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8d1467a684
During probe, return the "get_irq" error value instead of -ENOENT. This allows the driver to be defer probed if needed. Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com> Acked-by: Amelie Delaunay <amelie.delaunay@st.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2065 lines
57 KiB
C
2065 lines
57 KiB
C
// SPDX-License-Identifier: GPL-2.0
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//
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// STMicroelectronics STM32 SPI Controller driver (master mode only)
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//
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// Copyright (C) 2017, STMicroelectronics - All Rights Reserved
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// Author(s): Amelie Delaunay <amelie.delaunay@st.com> for STMicroelectronics.
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#include <linux/debugfs.h>
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/dmaengine.h>
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#include <linux/gpio.h>
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#include <linux/interrupt.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include <linux/pm_runtime.h>
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#include <linux/reset.h>
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#include <linux/spi/spi.h>
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#define DRIVER_NAME "spi_stm32"
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/* STM32F4 SPI registers */
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#define STM32F4_SPI_CR1 0x00
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#define STM32F4_SPI_CR2 0x04
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#define STM32F4_SPI_SR 0x08
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#define STM32F4_SPI_DR 0x0C
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#define STM32F4_SPI_I2SCFGR 0x1C
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/* STM32F4_SPI_CR1 bit fields */
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#define STM32F4_SPI_CR1_CPHA BIT(0)
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#define STM32F4_SPI_CR1_CPOL BIT(1)
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#define STM32F4_SPI_CR1_MSTR BIT(2)
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#define STM32F4_SPI_CR1_BR_SHIFT 3
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#define STM32F4_SPI_CR1_BR GENMASK(5, 3)
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#define STM32F4_SPI_CR1_SPE BIT(6)
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#define STM32F4_SPI_CR1_LSBFRST BIT(7)
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#define STM32F4_SPI_CR1_SSI BIT(8)
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#define STM32F4_SPI_CR1_SSM BIT(9)
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#define STM32F4_SPI_CR1_RXONLY BIT(10)
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#define STM32F4_SPI_CR1_DFF BIT(11)
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#define STM32F4_SPI_CR1_CRCNEXT BIT(12)
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#define STM32F4_SPI_CR1_CRCEN BIT(13)
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#define STM32F4_SPI_CR1_BIDIOE BIT(14)
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#define STM32F4_SPI_CR1_BIDIMODE BIT(15)
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#define STM32F4_SPI_CR1_BR_MIN 0
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#define STM32F4_SPI_CR1_BR_MAX (GENMASK(5, 3) >> 3)
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/* STM32F4_SPI_CR2 bit fields */
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#define STM32F4_SPI_CR2_RXDMAEN BIT(0)
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#define STM32F4_SPI_CR2_TXDMAEN BIT(1)
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#define STM32F4_SPI_CR2_SSOE BIT(2)
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#define STM32F4_SPI_CR2_FRF BIT(4)
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#define STM32F4_SPI_CR2_ERRIE BIT(5)
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#define STM32F4_SPI_CR2_RXNEIE BIT(6)
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#define STM32F4_SPI_CR2_TXEIE BIT(7)
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/* STM32F4_SPI_SR bit fields */
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#define STM32F4_SPI_SR_RXNE BIT(0)
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#define STM32F4_SPI_SR_TXE BIT(1)
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#define STM32F4_SPI_SR_CHSIDE BIT(2)
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#define STM32F4_SPI_SR_UDR BIT(3)
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#define STM32F4_SPI_SR_CRCERR BIT(4)
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#define STM32F4_SPI_SR_MODF BIT(5)
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#define STM32F4_SPI_SR_OVR BIT(6)
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#define STM32F4_SPI_SR_BSY BIT(7)
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#define STM32F4_SPI_SR_FRE BIT(8)
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/* STM32F4_SPI_I2SCFGR bit fields */
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#define STM32F4_SPI_I2SCFGR_I2SMOD BIT(11)
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/* STM32F4 SPI Baud Rate min/max divisor */
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#define STM32F4_SPI_BR_DIV_MIN (2 << STM32F4_SPI_CR1_BR_MIN)
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#define STM32F4_SPI_BR_DIV_MAX (2 << STM32F4_SPI_CR1_BR_MAX)
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/* STM32H7 SPI registers */
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#define STM32H7_SPI_CR1 0x00
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#define STM32H7_SPI_CR2 0x04
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#define STM32H7_SPI_CFG1 0x08
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#define STM32H7_SPI_CFG2 0x0C
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#define STM32H7_SPI_IER 0x10
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#define STM32H7_SPI_SR 0x14
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#define STM32H7_SPI_IFCR 0x18
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#define STM32H7_SPI_TXDR 0x20
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#define STM32H7_SPI_RXDR 0x30
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#define STM32H7_SPI_I2SCFGR 0x50
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/* STM32H7_SPI_CR1 bit fields */
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#define STM32H7_SPI_CR1_SPE BIT(0)
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#define STM32H7_SPI_CR1_MASRX BIT(8)
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#define STM32H7_SPI_CR1_CSTART BIT(9)
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#define STM32H7_SPI_CR1_CSUSP BIT(10)
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#define STM32H7_SPI_CR1_HDDIR BIT(11)
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#define STM32H7_SPI_CR1_SSI BIT(12)
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/* STM32H7_SPI_CR2 bit fields */
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#define STM32H7_SPI_CR2_TSIZE_SHIFT 0
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#define STM32H7_SPI_CR2_TSIZE GENMASK(15, 0)
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/* STM32H7_SPI_CFG1 bit fields */
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#define STM32H7_SPI_CFG1_DSIZE_SHIFT 0
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#define STM32H7_SPI_CFG1_DSIZE GENMASK(4, 0)
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#define STM32H7_SPI_CFG1_FTHLV_SHIFT 5
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#define STM32H7_SPI_CFG1_FTHLV GENMASK(8, 5)
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#define STM32H7_SPI_CFG1_RXDMAEN BIT(14)
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#define STM32H7_SPI_CFG1_TXDMAEN BIT(15)
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#define STM32H7_SPI_CFG1_MBR_SHIFT 28
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#define STM32H7_SPI_CFG1_MBR GENMASK(30, 28)
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#define STM32H7_SPI_CFG1_MBR_MIN 0
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#define STM32H7_SPI_CFG1_MBR_MAX (GENMASK(30, 28) >> 28)
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/* STM32H7_SPI_CFG2 bit fields */
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#define STM32H7_SPI_CFG2_MIDI_SHIFT 4
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#define STM32H7_SPI_CFG2_MIDI GENMASK(7, 4)
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#define STM32H7_SPI_CFG2_COMM_SHIFT 17
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#define STM32H7_SPI_CFG2_COMM GENMASK(18, 17)
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#define STM32H7_SPI_CFG2_SP_SHIFT 19
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#define STM32H7_SPI_CFG2_SP GENMASK(21, 19)
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#define STM32H7_SPI_CFG2_MASTER BIT(22)
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#define STM32H7_SPI_CFG2_LSBFRST BIT(23)
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#define STM32H7_SPI_CFG2_CPHA BIT(24)
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#define STM32H7_SPI_CFG2_CPOL BIT(25)
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#define STM32H7_SPI_CFG2_SSM BIT(26)
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#define STM32H7_SPI_CFG2_AFCNTR BIT(31)
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/* STM32H7_SPI_IER bit fields */
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#define STM32H7_SPI_IER_RXPIE BIT(0)
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#define STM32H7_SPI_IER_TXPIE BIT(1)
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#define STM32H7_SPI_IER_DXPIE BIT(2)
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#define STM32H7_SPI_IER_EOTIE BIT(3)
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#define STM32H7_SPI_IER_TXTFIE BIT(4)
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#define STM32H7_SPI_IER_OVRIE BIT(6)
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#define STM32H7_SPI_IER_MODFIE BIT(9)
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#define STM32H7_SPI_IER_ALL GENMASK(10, 0)
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/* STM32H7_SPI_SR bit fields */
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#define STM32H7_SPI_SR_RXP BIT(0)
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#define STM32H7_SPI_SR_TXP BIT(1)
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#define STM32H7_SPI_SR_EOT BIT(3)
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#define STM32H7_SPI_SR_OVR BIT(6)
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#define STM32H7_SPI_SR_MODF BIT(9)
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#define STM32H7_SPI_SR_SUSP BIT(11)
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#define STM32H7_SPI_SR_RXPLVL_SHIFT 13
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#define STM32H7_SPI_SR_RXPLVL GENMASK(14, 13)
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#define STM32H7_SPI_SR_RXWNE BIT(15)
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/* STM32H7_SPI_IFCR bit fields */
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#define STM32H7_SPI_IFCR_ALL GENMASK(11, 3)
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/* STM32H7_SPI_I2SCFGR bit fields */
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#define STM32H7_SPI_I2SCFGR_I2SMOD BIT(0)
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/* STM32H7 SPI Master Baud Rate min/max divisor */
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#define STM32H7_SPI_MBR_DIV_MIN (2 << STM32H7_SPI_CFG1_MBR_MIN)
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#define STM32H7_SPI_MBR_DIV_MAX (2 << STM32H7_SPI_CFG1_MBR_MAX)
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/* STM32H7 SPI Communication mode */
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#define STM32H7_SPI_FULL_DUPLEX 0
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#define STM32H7_SPI_SIMPLEX_TX 1
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#define STM32H7_SPI_SIMPLEX_RX 2
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#define STM32H7_SPI_HALF_DUPLEX 3
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/* SPI Communication type */
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#define SPI_FULL_DUPLEX 0
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#define SPI_SIMPLEX_TX 1
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#define SPI_SIMPLEX_RX 2
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#define SPI_3WIRE_TX 3
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#define SPI_3WIRE_RX 4
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#define SPI_1HZ_NS 1000000000
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/*
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* use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers
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* without fifo buffers.
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*/
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#define SPI_DMA_MIN_BYTES 16
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/**
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* stm32_spi_reg - stm32 SPI register & bitfield desc
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* @reg: register offset
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* @mask: bitfield mask
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* @shift: left shift
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*/
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struct stm32_spi_reg {
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int reg;
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int mask;
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int shift;
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};
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/**
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* stm32_spi_regspec - stm32 registers definition, compatible dependent data
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* en: enable register and SPI enable bit
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* dma_rx_en: SPI DMA RX enable register end SPI DMA RX enable bit
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* dma_tx_en: SPI DMA TX enable register end SPI DMA TX enable bit
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* cpol: clock polarity register and polarity bit
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* cpha: clock phase register and phase bit
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* lsb_first: LSB transmitted first register and bit
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* br: baud rate register and bitfields
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* rx: SPI RX data register
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* tx: SPI TX data register
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*/
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struct stm32_spi_regspec {
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const struct stm32_spi_reg en;
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const struct stm32_spi_reg dma_rx_en;
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const struct stm32_spi_reg dma_tx_en;
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const struct stm32_spi_reg cpol;
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const struct stm32_spi_reg cpha;
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const struct stm32_spi_reg lsb_first;
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const struct stm32_spi_reg br;
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const struct stm32_spi_reg rx;
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const struct stm32_spi_reg tx;
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};
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struct stm32_spi;
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/**
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* stm32_spi_cfg - stm32 compatible configuration data
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* @regs: registers descriptions
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* @get_fifo_size: routine to get fifo size
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* @get_bpw_mask: routine to get bits per word mask
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* @disable: routine to disable controller
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* @config: routine to configure controller as SPI Master
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* @set_bpw: routine to configure registers to for bits per word
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* @set_mode: routine to configure registers to desired mode
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* @set_data_idleness: optional routine to configure registers to desired idle
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* time between frames (if driver has this functionality)
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* set_number_of_data: optional routine to configure registers to desired
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* number of data (if driver has this functionality)
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* @can_dma: routine to determine if the transfer is eligible for DMA use
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* @transfer_one_dma_start: routine to start transfer a single spi_transfer
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* using DMA
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* @dma_rx cb: routine to call after DMA RX channel operation is complete
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* @dma_tx cb: routine to call after DMA TX channel operation is complete
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* @transfer_one_irq: routine to configure interrupts for driver
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* @irq_handler_event: Interrupt handler for SPI controller events
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* @irq_handler_thread: thread of interrupt handler for SPI controller
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* @baud_rate_div_min: minimum baud rate divisor
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* @baud_rate_div_max: maximum baud rate divisor
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* @has_fifo: boolean to know if fifo is used for driver
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* @has_startbit: boolean to know if start bit is used to start transfer
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*/
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struct stm32_spi_cfg {
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const struct stm32_spi_regspec *regs;
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int (*get_fifo_size)(struct stm32_spi *spi);
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int (*get_bpw_mask)(struct stm32_spi *spi);
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void (*disable)(struct stm32_spi *spi);
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int (*config)(struct stm32_spi *spi);
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void (*set_bpw)(struct stm32_spi *spi);
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int (*set_mode)(struct stm32_spi *spi, unsigned int comm_type);
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void (*set_data_idleness)(struct stm32_spi *spi, u32 length);
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int (*set_number_of_data)(struct stm32_spi *spi, u32 length);
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void (*transfer_one_dma_start)(struct stm32_spi *spi);
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void (*dma_rx_cb)(void *data);
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void (*dma_tx_cb)(void *data);
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int (*transfer_one_irq)(struct stm32_spi *spi);
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irqreturn_t (*irq_handler_event)(int irq, void *dev_id);
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irqreturn_t (*irq_handler_thread)(int irq, void *dev_id);
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unsigned int baud_rate_div_min;
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unsigned int baud_rate_div_max;
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bool has_fifo;
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};
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/**
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* struct stm32_spi - private data of the SPI controller
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* @dev: driver model representation of the controller
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* @master: controller master interface
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* @cfg: compatible configuration data
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* @base: virtual memory area
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* @clk: hw kernel clock feeding the SPI clock generator
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* @clk_rate: rate of the hw kernel clock feeding the SPI clock generator
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* @rst: SPI controller reset line
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* @lock: prevent I/O concurrent access
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* @irq: SPI controller interrupt line
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* @fifo_size: size of the embedded fifo in bytes
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* @cur_midi: master inter-data idleness in ns
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* @cur_speed: speed configured in Hz
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* @cur_bpw: number of bits in a single SPI data frame
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* @cur_fthlv: fifo threshold level (data frames in a single data packet)
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* @cur_comm: SPI communication mode
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* @cur_xferlen: current transfer length in bytes
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* @cur_usedma: boolean to know if dma is used in current transfer
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* @tx_buf: data to be written, or NULL
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* @rx_buf: data to be read, or NULL
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* @tx_len: number of data to be written in bytes
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* @rx_len: number of data to be read in bytes
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* @dma_tx: dma channel for TX transfer
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* @dma_rx: dma channel for RX transfer
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* @phys_addr: SPI registers physical base address
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*/
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struct stm32_spi {
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struct device *dev;
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struct spi_master *master;
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const struct stm32_spi_cfg *cfg;
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void __iomem *base;
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struct clk *clk;
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u32 clk_rate;
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struct reset_control *rst;
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spinlock_t lock; /* prevent I/O concurrent access */
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int irq;
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unsigned int fifo_size;
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unsigned int cur_midi;
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unsigned int cur_speed;
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unsigned int cur_bpw;
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unsigned int cur_fthlv;
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unsigned int cur_comm;
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unsigned int cur_xferlen;
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bool cur_usedma;
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const void *tx_buf;
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void *rx_buf;
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int tx_len;
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int rx_len;
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struct dma_chan *dma_tx;
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struct dma_chan *dma_rx;
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dma_addr_t phys_addr;
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};
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static const struct stm32_spi_regspec stm32f4_spi_regspec = {
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.en = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE },
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.dma_rx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_RXDMAEN },
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.dma_tx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN },
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.cpol = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPOL },
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.cpha = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPHA },
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.lsb_first = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_LSBFRST },
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.br = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_BR, STM32F4_SPI_CR1_BR_SHIFT },
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.rx = { STM32F4_SPI_DR },
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.tx = { STM32F4_SPI_DR },
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};
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static const struct stm32_spi_regspec stm32h7_spi_regspec = {
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/* SPI data transfer is enabled but spi_ker_ck is idle.
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* CFG1 and CFG2 registers are write protected when SPE is enabled.
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*/
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.en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
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.dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
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.dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
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.cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
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.cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
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.lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
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.br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
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STM32H7_SPI_CFG1_MBR_SHIFT },
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.rx = { STM32H7_SPI_RXDR },
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.tx = { STM32H7_SPI_TXDR },
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};
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static inline void stm32_spi_set_bits(struct stm32_spi *spi,
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u32 offset, u32 bits)
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{
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writel_relaxed(readl_relaxed(spi->base + offset) | bits,
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spi->base + offset);
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}
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static inline void stm32_spi_clr_bits(struct stm32_spi *spi,
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u32 offset, u32 bits)
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{
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writel_relaxed(readl_relaxed(spi->base + offset) & ~bits,
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spi->base + offset);
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}
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/**
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* stm32h7_spi_get_fifo_size - Return fifo size
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* @spi: pointer to the spi controller data structure
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*/
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static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi)
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{
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unsigned long flags;
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u32 count = 0;
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spin_lock_irqsave(&spi->lock, flags);
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stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
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while (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP)
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writeb_relaxed(++count, spi->base + STM32H7_SPI_TXDR);
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stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
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spin_unlock_irqrestore(&spi->lock, flags);
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dev_dbg(spi->dev, "%d x 8-bit fifo size\n", count);
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return count;
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}
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/**
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* stm32f4_spi_get_bpw_mask - Return bits per word mask
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* @spi: pointer to the spi controller data structure
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*/
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static int stm32f4_spi_get_bpw_mask(struct stm32_spi *spi)
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{
|
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dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
|
|
return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_get_bpw_mask - Return bits per word mask
|
|
* @spi: pointer to the spi controller data structure
|
|
*/
|
|
static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
u32 cfg1, max_bpw;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
/*
|
|
* The most significant bit at DSIZE bit field is reserved when the
|
|
* maximum data size of periperal instances is limited to 16-bit
|
|
*/
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_DSIZE);
|
|
|
|
cfg1 = readl_relaxed(spi->base + STM32H7_SPI_CFG1);
|
|
max_bpw = (cfg1 & STM32H7_SPI_CFG1_DSIZE) >>
|
|
STM32H7_SPI_CFG1_DSIZE_SHIFT;
|
|
max_bpw += 1;
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw);
|
|
|
|
return SPI_BPW_RANGE_MASK(4, max_bpw);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_prepare_mbr - Determine baud rate divisor value
|
|
* @spi: pointer to the spi controller data structure
|
|
* @speed_hz: requested speed
|
|
* @min_div: minimum baud rate divisor
|
|
* @max_div: maximum baud rate divisor
|
|
*
|
|
* Return baud rate divisor value in case of success or -EINVAL
|
|
*/
|
|
static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
|
|
u32 min_div, u32 max_div)
|
|
{
|
|
u32 div, mbrdiv;
|
|
|
|
div = DIV_ROUND_UP(spi->clk_rate, speed_hz);
|
|
|
|
/*
|
|
* SPI framework set xfer->speed_hz to master->max_speed_hz if
|
|
* xfer->speed_hz is greater than master->max_speed_hz, and it returns
|
|
* an error when xfer->speed_hz is lower than master->min_speed_hz, so
|
|
* no need to check it there.
|
|
* However, we need to ensure the following calculations.
|
|
*/
|
|
if ((div < min_div) || (div > max_div))
|
|
return -EINVAL;
|
|
|
|
/* Determine the first power of 2 greater than or equal to div */
|
|
if (div & (div - 1))
|
|
mbrdiv = fls(div);
|
|
else
|
|
mbrdiv = fls(div) - 1;
|
|
|
|
spi->cur_speed = spi->clk_rate / (1 << mbrdiv);
|
|
|
|
return mbrdiv - 1;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_prepare_fthlv - Determine FIFO threshold level
|
|
* @spi: pointer to the spi controller data structure
|
|
*/
|
|
static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi)
|
|
{
|
|
u32 fthlv, half_fifo;
|
|
|
|
/* data packet should not exceed 1/2 of fifo space */
|
|
half_fifo = (spi->fifo_size / 2);
|
|
|
|
if (spi->cur_bpw <= 8)
|
|
fthlv = half_fifo;
|
|
else if (spi->cur_bpw <= 16)
|
|
fthlv = half_fifo / 2;
|
|
else
|
|
fthlv = half_fifo / 4;
|
|
|
|
/* align packet size with data registers access */
|
|
if (spi->cur_bpw > 8)
|
|
fthlv -= (fthlv % 2); /* multiple of 2 */
|
|
else
|
|
fthlv -= (fthlv % 4); /* multiple of 4 */
|
|
|
|
return fthlv;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_write_tx - Write bytes to Transmit Data Register
|
|
* @spi: pointer to the spi controller data structure
|
|
*
|
|
* Read from tx_buf depends on remaining bytes to avoid to read beyond
|
|
* tx_buf end.
|
|
*/
|
|
static void stm32f4_spi_write_tx(struct stm32_spi *spi)
|
|
{
|
|
if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) &
|
|
STM32F4_SPI_SR_TXE)) {
|
|
u32 offs = spi->cur_xferlen - spi->tx_len;
|
|
|
|
if (spi->cur_bpw == 16) {
|
|
const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
|
|
|
|
writew_relaxed(*tx_buf16, spi->base + STM32F4_SPI_DR);
|
|
spi->tx_len -= sizeof(u16);
|
|
} else {
|
|
const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
|
|
|
|
writeb_relaxed(*tx_buf8, spi->base + STM32F4_SPI_DR);
|
|
spi->tx_len -= sizeof(u8);
|
|
}
|
|
}
|
|
|
|
dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_write_txfifo - Write bytes in Transmit Data Register
|
|
* @spi: pointer to the spi controller data structure
|
|
*
|
|
* Read from tx_buf depends on remaining bytes to avoid to read beyond
|
|
* tx_buf end.
|
|
*/
|
|
static void stm32h7_spi_write_txfifo(struct stm32_spi *spi)
|
|
{
|
|
while ((spi->tx_len > 0) &&
|
|
(readl_relaxed(spi->base + STM32H7_SPI_SR) &
|
|
STM32H7_SPI_SR_TXP)) {
|
|
u32 offs = spi->cur_xferlen - spi->tx_len;
|
|
|
|
if (spi->tx_len >= sizeof(u32)) {
|
|
const u32 *tx_buf32 = (const u32 *)(spi->tx_buf + offs);
|
|
|
|
writel_relaxed(*tx_buf32, spi->base + STM32H7_SPI_TXDR);
|
|
spi->tx_len -= sizeof(u32);
|
|
} else if (spi->tx_len >= sizeof(u16)) {
|
|
const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
|
|
|
|
writew_relaxed(*tx_buf16, spi->base + STM32H7_SPI_TXDR);
|
|
spi->tx_len -= sizeof(u16);
|
|
} else {
|
|
const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
|
|
|
|
writeb_relaxed(*tx_buf8, spi->base + STM32H7_SPI_TXDR);
|
|
spi->tx_len -= sizeof(u8);
|
|
}
|
|
}
|
|
|
|
dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_read_rx - Read bytes from Receive Data Register
|
|
* @spi: pointer to the spi controller data structure
|
|
*
|
|
* Write in rx_buf depends on remaining bytes to avoid to write beyond
|
|
* rx_buf end.
|
|
*/
|
|
static void stm32f4_spi_read_rx(struct stm32_spi *spi)
|
|
{
|
|
if ((spi->rx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) &
|
|
STM32F4_SPI_SR_RXNE)) {
|
|
u32 offs = spi->cur_xferlen - spi->rx_len;
|
|
|
|
if (spi->cur_bpw == 16) {
|
|
u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
|
|
|
|
*rx_buf16 = readw_relaxed(spi->base + STM32F4_SPI_DR);
|
|
spi->rx_len -= sizeof(u16);
|
|
} else {
|
|
u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
|
|
|
|
*rx_buf8 = readb_relaxed(spi->base + STM32F4_SPI_DR);
|
|
spi->rx_len -= sizeof(u8);
|
|
}
|
|
}
|
|
|
|
dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->rx_len);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register
|
|
* @spi: pointer to the spi controller data structure
|
|
*
|
|
* Write in rx_buf depends on remaining bytes to avoid to write beyond
|
|
* rx_buf end.
|
|
*/
|
|
static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush)
|
|
{
|
|
u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
|
|
u32 rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >>
|
|
STM32H7_SPI_SR_RXPLVL_SHIFT;
|
|
|
|
while ((spi->rx_len > 0) &&
|
|
((sr & STM32H7_SPI_SR_RXP) ||
|
|
(flush && ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) {
|
|
u32 offs = spi->cur_xferlen - spi->rx_len;
|
|
|
|
if ((spi->rx_len >= sizeof(u32)) ||
|
|
(flush && (sr & STM32H7_SPI_SR_RXWNE))) {
|
|
u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs);
|
|
|
|
*rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR);
|
|
spi->rx_len -= sizeof(u32);
|
|
} else if ((spi->rx_len >= sizeof(u16)) ||
|
|
(flush && (rxplvl >= 2 || spi->cur_bpw > 8))) {
|
|
u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
|
|
|
|
*rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR);
|
|
spi->rx_len -= sizeof(u16);
|
|
} else {
|
|
u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
|
|
|
|
*rx_buf8 = readb_relaxed(spi->base + STM32H7_SPI_RXDR);
|
|
spi->rx_len -= sizeof(u8);
|
|
}
|
|
|
|
sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
|
|
rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >>
|
|
STM32H7_SPI_SR_RXPLVL_SHIFT;
|
|
}
|
|
|
|
dev_dbg(spi->dev, "%s%s: %d bytes left\n", __func__,
|
|
flush ? "(flush)" : "", spi->rx_len);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_enable - Enable SPI controller
|
|
* @spi: pointer to the spi controller data structure
|
|
*/
|
|
static void stm32_spi_enable(struct stm32_spi *spi)
|
|
{
|
|
dev_dbg(spi->dev, "enable controller\n");
|
|
|
|
stm32_spi_set_bits(spi, spi->cfg->regs->en.reg,
|
|
spi->cfg->regs->en.mask);
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_disable - Disable SPI controller
|
|
* @spi: pointer to the spi controller data structure
|
|
*/
|
|
static void stm32f4_spi_disable(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
u32 sr;
|
|
|
|
dev_dbg(spi->dev, "disable controller\n");
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
if (!(readl_relaxed(spi->base + STM32F4_SPI_CR1) &
|
|
STM32F4_SPI_CR1_SPE)) {
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* Disable interrupts */
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXEIE |
|
|
STM32F4_SPI_CR2_RXNEIE |
|
|
STM32F4_SPI_CR2_ERRIE);
|
|
|
|
/* Wait until BSY = 0 */
|
|
if (readl_relaxed_poll_timeout_atomic(spi->base + STM32F4_SPI_SR,
|
|
sr, !(sr & STM32F4_SPI_SR_BSY),
|
|
10, 100000) < 0) {
|
|
dev_warn(spi->dev, "disabling condition timeout\n");
|
|
}
|
|
|
|
if (spi->cur_usedma && spi->dma_tx)
|
|
dmaengine_terminate_all(spi->dma_tx);
|
|
if (spi->cur_usedma && spi->dma_rx)
|
|
dmaengine_terminate_all(spi->dma_rx);
|
|
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE);
|
|
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN |
|
|
STM32F4_SPI_CR2_RXDMAEN);
|
|
|
|
/* Sequence to clear OVR flag */
|
|
readl_relaxed(spi->base + STM32F4_SPI_DR);
|
|
readl_relaxed(spi->base + STM32F4_SPI_SR);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_disable - Disable SPI controller
|
|
* @spi: pointer to the spi controller data structure
|
|
*
|
|
* RX-Fifo is flushed when SPI controller is disabled. To prevent any data
|
|
* loss, use stm32h7_spi_read_rxfifo(flush) to read the remaining bytes in
|
|
* RX-Fifo.
|
|
* Normally, if TSIZE has been configured, we should relax the hardware at the
|
|
* reception of the EOT interrupt. But in case of error, EOT will not be
|
|
* raised. So the subsystem unprepare_message call allows us to properly
|
|
* complete the transfer from an hardware point of view.
|
|
*/
|
|
static void stm32h7_spi_disable(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
u32 cr1, sr;
|
|
|
|
dev_dbg(spi->dev, "disable controller\n");
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
cr1 = readl_relaxed(spi->base + STM32H7_SPI_CR1);
|
|
|
|
if (!(cr1 & STM32H7_SPI_CR1_SPE)) {
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* Wait on EOT or suspend the flow */
|
|
if (readl_relaxed_poll_timeout_atomic(spi->base + STM32H7_SPI_SR,
|
|
sr, !(sr & STM32H7_SPI_SR_EOT),
|
|
10, 100000) < 0) {
|
|
if (cr1 & STM32H7_SPI_CR1_CSTART) {
|
|
writel_relaxed(cr1 | STM32H7_SPI_CR1_CSUSP,
|
|
spi->base + STM32H7_SPI_CR1);
|
|
if (readl_relaxed_poll_timeout_atomic(
|
|
spi->base + STM32H7_SPI_SR,
|
|
sr, !(sr & STM32H7_SPI_SR_SUSP),
|
|
10, 100000) < 0)
|
|
dev_warn(spi->dev,
|
|
"Suspend request timeout\n");
|
|
}
|
|
}
|
|
|
|
if (!spi->cur_usedma && spi->rx_buf && (spi->rx_len > 0))
|
|
stm32h7_spi_read_rxfifo(spi, true);
|
|
|
|
if (spi->cur_usedma && spi->dma_tx)
|
|
dmaengine_terminate_all(spi->dma_tx);
|
|
if (spi->cur_usedma && spi->dma_rx)
|
|
dmaengine_terminate_all(spi->dma_rx);
|
|
|
|
stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
|
|
|
|
stm32_spi_clr_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN |
|
|
STM32H7_SPI_CFG1_RXDMAEN);
|
|
|
|
/* Disable interrupts and clear status flags */
|
|
writel_relaxed(0, spi->base + STM32H7_SPI_IER);
|
|
writel_relaxed(STM32H7_SPI_IFCR_ALL, spi->base + STM32H7_SPI_IFCR);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_can_dma - Determine if the transfer is eligible for DMA use
|
|
*
|
|
* If driver has fifo and the current transfer size is greater than fifo size,
|
|
* use DMA. Otherwise use DMA for transfer longer than defined DMA min bytes.
|
|
*/
|
|
static bool stm32_spi_can_dma(struct spi_master *master,
|
|
struct spi_device *spi_dev,
|
|
struct spi_transfer *transfer)
|
|
{
|
|
unsigned int dma_size;
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
|
|
if (spi->cfg->has_fifo)
|
|
dma_size = spi->fifo_size;
|
|
else
|
|
dma_size = SPI_DMA_MIN_BYTES;
|
|
|
|
dev_dbg(spi->dev, "%s: %s\n", __func__,
|
|
(transfer->len > dma_size) ? "true" : "false");
|
|
|
|
return (transfer->len > dma_size);
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_irq_event - Interrupt handler for SPI controller events
|
|
* @irq: interrupt line
|
|
* @dev_id: SPI controller master interface
|
|
*/
|
|
static irqreturn_t stm32f4_spi_irq_event(int irq, void *dev_id)
|
|
{
|
|
struct spi_master *master = dev_id;
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
u32 sr, mask = 0;
|
|
unsigned long flags;
|
|
bool end = false;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
sr = readl_relaxed(spi->base + STM32F4_SPI_SR);
|
|
/*
|
|
* BSY flag is not handled in interrupt but it is normal behavior when
|
|
* this flag is set.
|
|
*/
|
|
sr &= ~STM32F4_SPI_SR_BSY;
|
|
|
|
if (!spi->cur_usedma && (spi->cur_comm == SPI_SIMPLEX_TX ||
|
|
spi->cur_comm == SPI_3WIRE_TX)) {
|
|
/* OVR flag shouldn't be handled for TX only mode */
|
|
sr &= ~STM32F4_SPI_SR_OVR | STM32F4_SPI_SR_RXNE;
|
|
mask |= STM32F4_SPI_SR_TXE;
|
|
}
|
|
|
|
if (!spi->cur_usedma && spi->cur_comm == SPI_FULL_DUPLEX) {
|
|
/* TXE flag is set and is handled when RXNE flag occurs */
|
|
sr &= ~STM32F4_SPI_SR_TXE;
|
|
mask |= STM32F4_SPI_SR_RXNE | STM32F4_SPI_SR_OVR;
|
|
}
|
|
|
|
if (!(sr & mask)) {
|
|
dev_dbg(spi->dev, "spurious IT (sr=0x%08x)\n", sr);
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
if (sr & STM32F4_SPI_SR_OVR) {
|
|
dev_warn(spi->dev, "Overrun: received value discarded\n");
|
|
|
|
/* Sequence to clear OVR flag */
|
|
readl_relaxed(spi->base + STM32F4_SPI_DR);
|
|
readl_relaxed(spi->base + STM32F4_SPI_SR);
|
|
|
|
/*
|
|
* If overrun is detected, it means that something went wrong,
|
|
* so stop the current transfer. Transfer can wait for next
|
|
* RXNE but DR is already read and end never happens.
|
|
*/
|
|
end = true;
|
|
goto end_irq;
|
|
}
|
|
|
|
if (sr & STM32F4_SPI_SR_TXE) {
|
|
if (spi->tx_buf)
|
|
stm32f4_spi_write_tx(spi);
|
|
if (spi->tx_len == 0)
|
|
end = true;
|
|
}
|
|
|
|
if (sr & STM32F4_SPI_SR_RXNE) {
|
|
stm32f4_spi_read_rx(spi);
|
|
if (spi->rx_len == 0)
|
|
end = true;
|
|
else /* Load data for discontinuous mode */
|
|
stm32f4_spi_write_tx(spi);
|
|
}
|
|
|
|
end_irq:
|
|
if (end) {
|
|
/* Immediately disable interrupts to do not generate new one */
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_CR2,
|
|
STM32F4_SPI_CR2_TXEIE |
|
|
STM32F4_SPI_CR2_RXNEIE |
|
|
STM32F4_SPI_CR2_ERRIE);
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
return IRQ_WAKE_THREAD;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_irq_thread - Thread of interrupt handler for SPI controller
|
|
* @irq: interrupt line
|
|
* @dev_id: SPI controller master interface
|
|
*/
|
|
static irqreturn_t stm32f4_spi_irq_thread(int irq, void *dev_id)
|
|
{
|
|
struct spi_master *master = dev_id;
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
|
|
spi_finalize_current_transfer(master);
|
|
stm32f4_spi_disable(spi);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_irq_thread - Thread of interrupt handler for SPI controller
|
|
* @irq: interrupt line
|
|
* @dev_id: SPI controller master interface
|
|
*/
|
|
static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
|
|
{
|
|
struct spi_master *master = dev_id;
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
u32 sr, ier, mask;
|
|
unsigned long flags;
|
|
bool end = false;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
|
|
ier = readl_relaxed(spi->base + STM32H7_SPI_IER);
|
|
|
|
mask = ier;
|
|
/* EOTIE is triggered on EOT, SUSP and TXC events. */
|
|
mask |= STM32H7_SPI_SR_SUSP;
|
|
/*
|
|
* When TXTF is set, DXPIE and TXPIE are cleared. So in case of
|
|
* Full-Duplex, need to poll RXP event to know if there are remaining
|
|
* data, before disabling SPI.
|
|
*/
|
|
if (spi->rx_buf && !spi->cur_usedma)
|
|
mask |= STM32H7_SPI_SR_RXP;
|
|
|
|
if (!(sr & mask)) {
|
|
dev_dbg(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
|
|
sr, ier);
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
if (sr & STM32H7_SPI_SR_SUSP) {
|
|
dev_warn(spi->dev, "Communication suspended\n");
|
|
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
|
|
stm32h7_spi_read_rxfifo(spi, false);
|
|
/*
|
|
* If communication is suspended while using DMA, it means
|
|
* that something went wrong, so stop the current transfer
|
|
*/
|
|
if (spi->cur_usedma)
|
|
end = true;
|
|
}
|
|
|
|
if (sr & STM32H7_SPI_SR_MODF) {
|
|
dev_warn(spi->dev, "Mode fault: transfer aborted\n");
|
|
end = true;
|
|
}
|
|
|
|
if (sr & STM32H7_SPI_SR_OVR) {
|
|
dev_warn(spi->dev, "Overrun: received value discarded\n");
|
|
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
|
|
stm32h7_spi_read_rxfifo(spi, false);
|
|
/*
|
|
* If overrun is detected while using DMA, it means that
|
|
* something went wrong, so stop the current transfer
|
|
*/
|
|
if (spi->cur_usedma)
|
|
end = true;
|
|
}
|
|
|
|
if (sr & STM32H7_SPI_SR_EOT) {
|
|
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
|
|
stm32h7_spi_read_rxfifo(spi, true);
|
|
end = true;
|
|
}
|
|
|
|
if (sr & STM32H7_SPI_SR_TXP)
|
|
if (!spi->cur_usedma && (spi->tx_buf && (spi->tx_len > 0)))
|
|
stm32h7_spi_write_txfifo(spi);
|
|
|
|
if (sr & STM32H7_SPI_SR_RXP)
|
|
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
|
|
stm32h7_spi_read_rxfifo(spi, false);
|
|
|
|
writel_relaxed(mask, spi->base + STM32H7_SPI_IFCR);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
if (end) {
|
|
spi_finalize_current_transfer(master);
|
|
stm32h7_spi_disable(spi);
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_setup - setup device chip select
|
|
*/
|
|
static int stm32_spi_setup(struct spi_device *spi_dev)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!gpio_is_valid(spi_dev->cs_gpio)) {
|
|
dev_err(&spi_dev->dev, "%d is not a valid gpio\n",
|
|
spi_dev->cs_gpio);
|
|
return -EINVAL;
|
|
}
|
|
|
|
dev_dbg(&spi_dev->dev, "%s: set gpio%d output %s\n", __func__,
|
|
spi_dev->cs_gpio,
|
|
(spi_dev->mode & SPI_CS_HIGH) ? "low" : "high");
|
|
|
|
ret = gpio_direction_output(spi_dev->cs_gpio,
|
|
!(spi_dev->mode & SPI_CS_HIGH));
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_prepare_msg - set up the controller to transfer a single message
|
|
*/
|
|
static int stm32_spi_prepare_msg(struct spi_master *master,
|
|
struct spi_message *msg)
|
|
{
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
struct spi_device *spi_dev = msg->spi;
|
|
struct device_node *np = spi_dev->dev.of_node;
|
|
unsigned long flags;
|
|
u32 clrb = 0, setb = 0;
|
|
|
|
/* SPI slave device may need time between data frames */
|
|
spi->cur_midi = 0;
|
|
if (np && !of_property_read_u32(np, "st,spi-midi-ns", &spi->cur_midi))
|
|
dev_dbg(spi->dev, "%dns inter-data idleness\n", spi->cur_midi);
|
|
|
|
if (spi_dev->mode & SPI_CPOL)
|
|
setb |= spi->cfg->regs->cpol.mask;
|
|
else
|
|
clrb |= spi->cfg->regs->cpol.mask;
|
|
|
|
if (spi_dev->mode & SPI_CPHA)
|
|
setb |= spi->cfg->regs->cpha.mask;
|
|
else
|
|
clrb |= spi->cfg->regs->cpha.mask;
|
|
|
|
if (spi_dev->mode & SPI_LSB_FIRST)
|
|
setb |= spi->cfg->regs->lsb_first.mask;
|
|
else
|
|
clrb |= spi->cfg->regs->lsb_first.mask;
|
|
|
|
dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n",
|
|
spi_dev->mode & SPI_CPOL,
|
|
spi_dev->mode & SPI_CPHA,
|
|
spi_dev->mode & SPI_LSB_FIRST,
|
|
spi_dev->mode & SPI_CS_HIGH);
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
/* CPOL, CPHA and LSB FIRST bits have common register */
|
|
if (clrb || setb)
|
|
writel_relaxed(
|
|
(readl_relaxed(spi->base + spi->cfg->regs->cpol.reg) &
|
|
~clrb) | setb,
|
|
spi->base + spi->cfg->regs->cpol.reg);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_dma_tx_cb - dma callback
|
|
*
|
|
* DMA callback is called when the transfer is complete for DMA TX channel.
|
|
*/
|
|
static void stm32f4_spi_dma_tx_cb(void *data)
|
|
{
|
|
struct stm32_spi *spi = data;
|
|
|
|
if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
|
|
spi_finalize_current_transfer(spi->master);
|
|
stm32f4_spi_disable(spi);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_dma_rx_cb - dma callback
|
|
*
|
|
* DMA callback is called when the transfer is complete for DMA RX channel.
|
|
*/
|
|
static void stm32f4_spi_dma_rx_cb(void *data)
|
|
{
|
|
struct stm32_spi *spi = data;
|
|
|
|
spi_finalize_current_transfer(spi->master);
|
|
stm32f4_spi_disable(spi);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_dma_cb - dma callback
|
|
*
|
|
* DMA callback is called when the transfer is complete or when an error
|
|
* occurs. If the transfer is complete, EOT flag is raised.
|
|
*/
|
|
static void stm32h7_spi_dma_cb(void *data)
|
|
{
|
|
struct stm32_spi *spi = data;
|
|
unsigned long flags;
|
|
u32 sr;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
if (!(sr & STM32H7_SPI_SR_EOT))
|
|
dev_warn(spi->dev, "DMA error (sr=0x%08x)\n", sr);
|
|
|
|
/* Now wait for EOT, or SUSP or OVR in case of error */
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_dma_config - configure dma slave channel depending on current
|
|
* transfer bits_per_word.
|
|
*/
|
|
static void stm32_spi_dma_config(struct stm32_spi *spi,
|
|
struct dma_slave_config *dma_conf,
|
|
enum dma_transfer_direction dir)
|
|
{
|
|
enum dma_slave_buswidth buswidth;
|
|
u32 maxburst;
|
|
|
|
if (spi->cur_bpw <= 8)
|
|
buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
|
|
else if (spi->cur_bpw <= 16)
|
|
buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
|
|
else
|
|
buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
|
|
|
|
if (spi->cfg->has_fifo) {
|
|
/* Valid for DMA Half or Full Fifo threshold */
|
|
if (spi->cur_fthlv == 2)
|
|
maxburst = 1;
|
|
else
|
|
maxburst = spi->cur_fthlv;
|
|
} else {
|
|
maxburst = 1;
|
|
}
|
|
|
|
memset(dma_conf, 0, sizeof(struct dma_slave_config));
|
|
dma_conf->direction = dir;
|
|
if (dma_conf->direction == DMA_DEV_TO_MEM) { /* RX */
|
|
dma_conf->src_addr = spi->phys_addr + spi->cfg->regs->rx.reg;
|
|
dma_conf->src_addr_width = buswidth;
|
|
dma_conf->src_maxburst = maxburst;
|
|
|
|
dev_dbg(spi->dev, "Rx DMA config buswidth=%d, maxburst=%d\n",
|
|
buswidth, maxburst);
|
|
} else if (dma_conf->direction == DMA_MEM_TO_DEV) { /* TX */
|
|
dma_conf->dst_addr = spi->phys_addr + spi->cfg->regs->tx.reg;
|
|
dma_conf->dst_addr_width = buswidth;
|
|
dma_conf->dst_maxburst = maxburst;
|
|
|
|
dev_dbg(spi->dev, "Tx DMA config buswidth=%d, maxburst=%d\n",
|
|
buswidth, maxburst);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_transfer_one_irq - transfer a single spi_transfer using
|
|
* interrupts
|
|
*
|
|
* It must returns 0 if the transfer is finished or 1 if the transfer is still
|
|
* in progress.
|
|
*/
|
|
static int stm32f4_spi_transfer_one_irq(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
u32 cr2 = 0;
|
|
|
|
/* Enable the interrupts relative to the current communication mode */
|
|
if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
|
|
cr2 |= STM32F4_SPI_CR2_TXEIE;
|
|
} else if (spi->cur_comm == SPI_FULL_DUPLEX) {
|
|
/* In transmit-only mode, the OVR flag is set in the SR register
|
|
* since the received data are never read. Therefore set OVR
|
|
* interrupt only when rx buffer is available.
|
|
*/
|
|
cr2 |= STM32F4_SPI_CR2_RXNEIE | STM32F4_SPI_CR2_ERRIE;
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
stm32_spi_set_bits(spi, STM32F4_SPI_CR2, cr2);
|
|
|
|
stm32_spi_enable(spi);
|
|
|
|
/* starting data transfer when buffer is loaded */
|
|
if (spi->tx_buf)
|
|
stm32f4_spi_write_tx(spi);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using
|
|
* interrupts
|
|
*
|
|
* It must returns 0 if the transfer is finished or 1 if the transfer is still
|
|
* in progress.
|
|
*/
|
|
static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
u32 ier = 0;
|
|
|
|
/* Enable the interrupts relative to the current communication mode */
|
|
if (spi->tx_buf && spi->rx_buf) /* Full Duplex */
|
|
ier |= STM32H7_SPI_IER_DXPIE;
|
|
else if (spi->tx_buf) /* Half-Duplex TX dir or Simplex TX */
|
|
ier |= STM32H7_SPI_IER_TXPIE;
|
|
else if (spi->rx_buf) /* Half-Duplex RX dir or Simplex RX */
|
|
ier |= STM32H7_SPI_IER_RXPIE;
|
|
|
|
/* Enable the interrupts relative to the end of transfer */
|
|
ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE |
|
|
STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
stm32_spi_enable(spi);
|
|
|
|
/* Be sure to have data in fifo before starting data transfer */
|
|
if (spi->tx_buf)
|
|
stm32h7_spi_write_txfifo(spi);
|
|
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
|
|
|
|
writel_relaxed(ier, spi->base + STM32H7_SPI_IER);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_transfer_one_dma_start - Set SPI driver registers to start
|
|
* transfer using DMA
|
|
*/
|
|
static void stm32f4_spi_transfer_one_dma_start(struct stm32_spi *spi)
|
|
{
|
|
/* In DMA mode end of transfer is handled by DMA TX or RX callback. */
|
|
if (spi->cur_comm == SPI_SIMPLEX_RX || spi->cur_comm == SPI_3WIRE_RX ||
|
|
spi->cur_comm == SPI_FULL_DUPLEX) {
|
|
/*
|
|
* In transmit-only mode, the OVR flag is set in the SR register
|
|
* since the received data are never read. Therefore set OVR
|
|
* interrupt only when rx buffer is available.
|
|
*/
|
|
stm32_spi_set_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_ERRIE);
|
|
}
|
|
|
|
stm32_spi_enable(spi);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start
|
|
* transfer using DMA
|
|
*/
|
|
static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
|
|
{
|
|
/* Enable the interrupts relative to the end of transfer */
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_IER, STM32H7_SPI_IER_EOTIE |
|
|
STM32H7_SPI_IER_TXTFIE |
|
|
STM32H7_SPI_IER_OVRIE |
|
|
STM32H7_SPI_IER_MODFIE);
|
|
|
|
stm32_spi_enable(spi);
|
|
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_transfer_one_dma - transfer a single spi_transfer using DMA
|
|
*
|
|
* It must returns 0 if the transfer is finished or 1 if the transfer is still
|
|
* in progress.
|
|
*/
|
|
static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
|
|
struct spi_transfer *xfer)
|
|
{
|
|
struct dma_slave_config tx_dma_conf, rx_dma_conf;
|
|
struct dma_async_tx_descriptor *tx_dma_desc, *rx_dma_desc;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
rx_dma_desc = NULL;
|
|
if (spi->rx_buf && spi->dma_rx) {
|
|
stm32_spi_dma_config(spi, &rx_dma_conf, DMA_DEV_TO_MEM);
|
|
dmaengine_slave_config(spi->dma_rx, &rx_dma_conf);
|
|
|
|
/* Enable Rx DMA request */
|
|
stm32_spi_set_bits(spi, spi->cfg->regs->dma_rx_en.reg,
|
|
spi->cfg->regs->dma_rx_en.mask);
|
|
|
|
rx_dma_desc = dmaengine_prep_slave_sg(
|
|
spi->dma_rx, xfer->rx_sg.sgl,
|
|
xfer->rx_sg.nents,
|
|
rx_dma_conf.direction,
|
|
DMA_PREP_INTERRUPT);
|
|
}
|
|
|
|
tx_dma_desc = NULL;
|
|
if (spi->tx_buf && spi->dma_tx) {
|
|
stm32_spi_dma_config(spi, &tx_dma_conf, DMA_MEM_TO_DEV);
|
|
dmaengine_slave_config(spi->dma_tx, &tx_dma_conf);
|
|
|
|
tx_dma_desc = dmaengine_prep_slave_sg(
|
|
spi->dma_tx, xfer->tx_sg.sgl,
|
|
xfer->tx_sg.nents,
|
|
tx_dma_conf.direction,
|
|
DMA_PREP_INTERRUPT);
|
|
}
|
|
|
|
if ((spi->tx_buf && spi->dma_tx && !tx_dma_desc) ||
|
|
(spi->rx_buf && spi->dma_rx && !rx_dma_desc))
|
|
goto dma_desc_error;
|
|
|
|
if (spi->cur_comm == SPI_FULL_DUPLEX && (!tx_dma_desc || !rx_dma_desc))
|
|
goto dma_desc_error;
|
|
|
|
if (rx_dma_desc) {
|
|
rx_dma_desc->callback = spi->cfg->dma_rx_cb;
|
|
rx_dma_desc->callback_param = spi;
|
|
|
|
if (dma_submit_error(dmaengine_submit(rx_dma_desc))) {
|
|
dev_err(spi->dev, "Rx DMA submit failed\n");
|
|
goto dma_desc_error;
|
|
}
|
|
/* Enable Rx DMA channel */
|
|
dma_async_issue_pending(spi->dma_rx);
|
|
}
|
|
|
|
if (tx_dma_desc) {
|
|
if (spi->cur_comm == SPI_SIMPLEX_TX ||
|
|
spi->cur_comm == SPI_3WIRE_TX) {
|
|
tx_dma_desc->callback = spi->cfg->dma_tx_cb;
|
|
tx_dma_desc->callback_param = spi;
|
|
}
|
|
|
|
if (dma_submit_error(dmaengine_submit(tx_dma_desc))) {
|
|
dev_err(spi->dev, "Tx DMA submit failed\n");
|
|
goto dma_submit_error;
|
|
}
|
|
/* Enable Tx DMA channel */
|
|
dma_async_issue_pending(spi->dma_tx);
|
|
|
|
/* Enable Tx DMA request */
|
|
stm32_spi_set_bits(spi, spi->cfg->regs->dma_tx_en.reg,
|
|
spi->cfg->regs->dma_tx_en.mask);
|
|
}
|
|
|
|
spi->cfg->transfer_one_dma_start(spi);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return 1;
|
|
|
|
dma_submit_error:
|
|
if (spi->dma_rx)
|
|
dmaengine_terminate_all(spi->dma_rx);
|
|
|
|
dma_desc_error:
|
|
stm32_spi_clr_bits(spi, spi->cfg->regs->dma_rx_en.reg,
|
|
spi->cfg->regs->dma_rx_en.mask);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
dev_info(spi->dev, "DMA issue: fall back to irq transfer\n");
|
|
|
|
spi->cur_usedma = false;
|
|
return spi->cfg->transfer_one_irq(spi);
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_set_bpw - Configure bits per word
|
|
* @spi: pointer to the spi controller data structure
|
|
*/
|
|
static void stm32f4_spi_set_bpw(struct stm32_spi *spi)
|
|
{
|
|
if (spi->cur_bpw == 16)
|
|
stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF);
|
|
else
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_set_bpw - configure bits per word
|
|
* @spi: pointer to the spi controller data structure
|
|
*/
|
|
static void stm32h7_spi_set_bpw(struct stm32_spi *spi)
|
|
{
|
|
u32 bpw, fthlv;
|
|
u32 cfg1_clrb = 0, cfg1_setb = 0;
|
|
|
|
bpw = spi->cur_bpw - 1;
|
|
|
|
cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE;
|
|
cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) &
|
|
STM32H7_SPI_CFG1_DSIZE;
|
|
|
|
spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi);
|
|
fthlv = spi->cur_fthlv - 1;
|
|
|
|
cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
|
|
cfg1_setb |= (fthlv << STM32H7_SPI_CFG1_FTHLV_SHIFT) &
|
|
STM32H7_SPI_CFG1_FTHLV;
|
|
|
|
writel_relaxed(
|
|
(readl_relaxed(spi->base + STM32H7_SPI_CFG1) &
|
|
~cfg1_clrb) | cfg1_setb,
|
|
spi->base + STM32H7_SPI_CFG1);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_set_mbr - Configure baud rate divisor in master mode
|
|
* @spi: pointer to the spi controller data structure
|
|
* @mbrdiv: baud rate divisor value
|
|
*/
|
|
static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv)
|
|
{
|
|
u32 clrb = 0, setb = 0;
|
|
|
|
clrb |= spi->cfg->regs->br.mask;
|
|
setb |= ((u32)mbrdiv << spi->cfg->regs->br.shift) &
|
|
spi->cfg->regs->br.mask;
|
|
|
|
writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) &
|
|
~clrb) | setb,
|
|
spi->base + spi->cfg->regs->br.reg);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_communication_type - return transfer communication type
|
|
* @spi_dev: pointer to the spi device
|
|
* transfer: pointer to spi transfer
|
|
*/
|
|
static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev,
|
|
struct spi_transfer *transfer)
|
|
{
|
|
unsigned int type = SPI_FULL_DUPLEX;
|
|
|
|
if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */
|
|
/*
|
|
* SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL
|
|
* is forbidden and unvalidated by SPI subsystem so depending
|
|
* on the valid buffer, we can determine the direction of the
|
|
* transfer.
|
|
*/
|
|
if (!transfer->tx_buf)
|
|
type = SPI_3WIRE_RX;
|
|
else
|
|
type = SPI_3WIRE_TX;
|
|
} else {
|
|
if (!transfer->tx_buf)
|
|
type = SPI_SIMPLEX_RX;
|
|
else if (!transfer->rx_buf)
|
|
type = SPI_SIMPLEX_TX;
|
|
}
|
|
|
|
return type;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_set_mode - configure communication mode
|
|
* @spi: pointer to the spi controller data structure
|
|
* @comm_type: type of communication to configure
|
|
*/
|
|
static int stm32f4_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
|
|
{
|
|
if (comm_type == SPI_3WIRE_TX || comm_type == SPI_SIMPLEX_TX) {
|
|
stm32_spi_set_bits(spi, STM32F4_SPI_CR1,
|
|
STM32F4_SPI_CR1_BIDIMODE |
|
|
STM32F4_SPI_CR1_BIDIOE);
|
|
} else if (comm_type == SPI_FULL_DUPLEX) {
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_CR1,
|
|
STM32F4_SPI_CR1_BIDIMODE |
|
|
STM32F4_SPI_CR1_BIDIOE);
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_set_mode - configure communication mode
|
|
* @spi: pointer to the spi controller data structure
|
|
* @comm_type: type of communication to configure
|
|
*/
|
|
static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
|
|
{
|
|
u32 mode;
|
|
u32 cfg2_clrb = 0, cfg2_setb = 0;
|
|
|
|
if (comm_type == SPI_3WIRE_RX) {
|
|
mode = STM32H7_SPI_HALF_DUPLEX;
|
|
stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
|
|
} else if (comm_type == SPI_3WIRE_TX) {
|
|
mode = STM32H7_SPI_HALF_DUPLEX;
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
|
|
} else if (comm_type == SPI_SIMPLEX_RX) {
|
|
mode = STM32H7_SPI_SIMPLEX_RX;
|
|
} else if (comm_type == SPI_SIMPLEX_TX) {
|
|
mode = STM32H7_SPI_SIMPLEX_TX;
|
|
} else {
|
|
mode = STM32H7_SPI_FULL_DUPLEX;
|
|
}
|
|
|
|
cfg2_clrb |= STM32H7_SPI_CFG2_COMM;
|
|
cfg2_setb |= (mode << STM32H7_SPI_CFG2_COMM_SHIFT) &
|
|
STM32H7_SPI_CFG2_COMM;
|
|
|
|
writel_relaxed(
|
|
(readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
|
|
~cfg2_clrb) | cfg2_setb,
|
|
spi->base + STM32H7_SPI_CFG2);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_data_idleness - configure minimum time delay inserted between two
|
|
* consecutive data frames in master mode
|
|
* @spi: pointer to the spi controller data structure
|
|
* @len: transfer len
|
|
*/
|
|
static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len)
|
|
{
|
|
u32 cfg2_clrb = 0, cfg2_setb = 0;
|
|
|
|
cfg2_clrb |= STM32H7_SPI_CFG2_MIDI;
|
|
if ((len > 1) && (spi->cur_midi > 0)) {
|
|
u32 sck_period_ns = DIV_ROUND_UP(SPI_1HZ_NS, spi->cur_speed);
|
|
u32 midi = min((u32)DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
|
|
(u32)STM32H7_SPI_CFG2_MIDI >>
|
|
STM32H7_SPI_CFG2_MIDI_SHIFT);
|
|
|
|
dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n",
|
|
sck_period_ns, midi, midi * sck_period_ns);
|
|
cfg2_setb |= (midi << STM32H7_SPI_CFG2_MIDI_SHIFT) &
|
|
STM32H7_SPI_CFG2_MIDI;
|
|
}
|
|
|
|
writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
|
|
~cfg2_clrb) | cfg2_setb,
|
|
spi->base + STM32H7_SPI_CFG2);
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_number_of_data - configure number of data at current transfer
|
|
* @spi: pointer to the spi controller data structure
|
|
* @len: transfer length
|
|
*/
|
|
static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words)
|
|
{
|
|
u32 cr2_clrb = 0, cr2_setb = 0;
|
|
|
|
if (nb_words <= (STM32H7_SPI_CR2_TSIZE >>
|
|
STM32H7_SPI_CR2_TSIZE_SHIFT)) {
|
|
cr2_clrb |= STM32H7_SPI_CR2_TSIZE;
|
|
cr2_setb = nb_words << STM32H7_SPI_CR2_TSIZE_SHIFT;
|
|
writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CR2) &
|
|
~cr2_clrb) | cr2_setb,
|
|
spi->base + STM32H7_SPI_CR2);
|
|
} else {
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_transfer_one_setup - common setup to transfer a single
|
|
* spi_transfer either using DMA or
|
|
* interrupts.
|
|
*/
|
|
static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
|
|
struct spi_device *spi_dev,
|
|
struct spi_transfer *transfer)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int comm_type;
|
|
int nb_words, ret = 0;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
if (spi->cur_bpw != transfer->bits_per_word) {
|
|
spi->cur_bpw = transfer->bits_per_word;
|
|
spi->cfg->set_bpw(spi);
|
|
}
|
|
|
|
if (spi->cur_speed != transfer->speed_hz) {
|
|
int mbr;
|
|
|
|
/* Update spi->cur_speed with real clock speed */
|
|
mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
|
|
spi->cfg->baud_rate_div_min,
|
|
spi->cfg->baud_rate_div_max);
|
|
if (mbr < 0) {
|
|
ret = mbr;
|
|
goto out;
|
|
}
|
|
|
|
transfer->speed_hz = spi->cur_speed;
|
|
stm32_spi_set_mbr(spi, mbr);
|
|
}
|
|
|
|
comm_type = stm32_spi_communication_type(spi_dev, transfer);
|
|
if (spi->cur_comm != comm_type) {
|
|
ret = spi->cfg->set_mode(spi, comm_type);
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
spi->cur_comm = comm_type;
|
|
}
|
|
|
|
if (spi->cfg->set_data_idleness)
|
|
spi->cfg->set_data_idleness(spi, transfer->len);
|
|
|
|
if (spi->cur_bpw <= 8)
|
|
nb_words = transfer->len;
|
|
else if (spi->cur_bpw <= 16)
|
|
nb_words = DIV_ROUND_UP(transfer->len * 8, 16);
|
|
else
|
|
nb_words = DIV_ROUND_UP(transfer->len * 8, 32);
|
|
|
|
if (spi->cfg->set_number_of_data) {
|
|
ret = spi->cfg->set_number_of_data(spi, nb_words);
|
|
if (ret < 0)
|
|
goto out;
|
|
}
|
|
|
|
spi->cur_xferlen = transfer->len;
|
|
|
|
dev_dbg(spi->dev, "transfer communication mode set to %d\n",
|
|
spi->cur_comm);
|
|
dev_dbg(spi->dev,
|
|
"data frame of %d-bit, data packet of %d data frames\n",
|
|
spi->cur_bpw, spi->cur_fthlv);
|
|
dev_dbg(spi->dev, "speed set to %dHz\n", spi->cur_speed);
|
|
dev_dbg(spi->dev, "transfer of %d bytes (%d data frames)\n",
|
|
spi->cur_xferlen, nb_words);
|
|
dev_dbg(spi->dev, "dma %s\n",
|
|
(spi->cur_usedma) ? "enabled" : "disabled");
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_transfer_one - transfer a single spi_transfer
|
|
*
|
|
* It must return 0 if the transfer is finished or 1 if the transfer is still
|
|
* in progress.
|
|
*/
|
|
static int stm32_spi_transfer_one(struct spi_master *master,
|
|
struct spi_device *spi_dev,
|
|
struct spi_transfer *transfer)
|
|
{
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
int ret;
|
|
|
|
spi->tx_buf = transfer->tx_buf;
|
|
spi->rx_buf = transfer->rx_buf;
|
|
spi->tx_len = spi->tx_buf ? transfer->len : 0;
|
|
spi->rx_len = spi->rx_buf ? transfer->len : 0;
|
|
|
|
spi->cur_usedma = (master->can_dma &&
|
|
master->can_dma(master, spi_dev, transfer));
|
|
|
|
ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer);
|
|
if (ret) {
|
|
dev_err(spi->dev, "SPI transfer setup failed\n");
|
|
return ret;
|
|
}
|
|
|
|
if (spi->cur_usedma)
|
|
return stm32_spi_transfer_one_dma(spi, transfer);
|
|
else
|
|
return spi->cfg->transfer_one_irq(spi);
|
|
}
|
|
|
|
/**
|
|
* stm32_spi_unprepare_msg - relax the hardware
|
|
*/
|
|
static int stm32_spi_unprepare_msg(struct spi_master *master,
|
|
struct spi_message *msg)
|
|
{
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
|
|
spi->cfg->disable(spi);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32f4_spi_config - Configure SPI controller as SPI master
|
|
*/
|
|
static int stm32f4_spi_config(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
/* Ensure I2SMOD bit is kept cleared */
|
|
stm32_spi_clr_bits(spi, STM32F4_SPI_I2SCFGR,
|
|
STM32F4_SPI_I2SCFGR_I2SMOD);
|
|
|
|
/*
|
|
* - SS input value high
|
|
* - transmitter half duplex direction
|
|
* - Set the master mode (default Motorola mode)
|
|
* - Consider 1 master/n slaves configuration and
|
|
* SS input value is determined by the SSI bit
|
|
*/
|
|
stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SSI |
|
|
STM32F4_SPI_CR1_BIDIOE |
|
|
STM32F4_SPI_CR1_MSTR |
|
|
STM32F4_SPI_CR1_SSM);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* stm32h7_spi_config - Configure SPI controller as SPI master
|
|
*/
|
|
static int stm32h7_spi_config(struct stm32_spi *spi)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&spi->lock, flags);
|
|
|
|
/* Ensure I2SMOD bit is kept cleared */
|
|
stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR,
|
|
STM32H7_SPI_I2SCFGR_I2SMOD);
|
|
|
|
/*
|
|
* - SS input value high
|
|
* - transmitter half duplex direction
|
|
* - automatic communication suspend when RX-Fifo is full
|
|
*/
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SSI |
|
|
STM32H7_SPI_CR1_HDDIR |
|
|
STM32H7_SPI_CR1_MASRX);
|
|
|
|
/*
|
|
* - Set the master mode (default Motorola mode)
|
|
* - Consider 1 master/n slaves configuration and
|
|
* SS input value is determined by the SSI bit
|
|
* - keep control of all associated GPIOs
|
|
*/
|
|
stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_MASTER |
|
|
STM32H7_SPI_CFG2_SSM |
|
|
STM32H7_SPI_CFG2_AFCNTR);
|
|
|
|
spin_unlock_irqrestore(&spi->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct stm32_spi_cfg stm32f4_spi_cfg = {
|
|
.regs = &stm32f4_spi_regspec,
|
|
.get_bpw_mask = stm32f4_spi_get_bpw_mask,
|
|
.disable = stm32f4_spi_disable,
|
|
.config = stm32f4_spi_config,
|
|
.set_bpw = stm32f4_spi_set_bpw,
|
|
.set_mode = stm32f4_spi_set_mode,
|
|
.transfer_one_dma_start = stm32f4_spi_transfer_one_dma_start,
|
|
.dma_tx_cb = stm32f4_spi_dma_tx_cb,
|
|
.dma_rx_cb = stm32f4_spi_dma_rx_cb,
|
|
.transfer_one_irq = stm32f4_spi_transfer_one_irq,
|
|
.irq_handler_event = stm32f4_spi_irq_event,
|
|
.irq_handler_thread = stm32f4_spi_irq_thread,
|
|
.baud_rate_div_min = STM32F4_SPI_BR_DIV_MIN,
|
|
.baud_rate_div_max = STM32F4_SPI_BR_DIV_MAX,
|
|
.has_fifo = false,
|
|
};
|
|
|
|
static const struct stm32_spi_cfg stm32h7_spi_cfg = {
|
|
.regs = &stm32h7_spi_regspec,
|
|
.get_fifo_size = stm32h7_spi_get_fifo_size,
|
|
.get_bpw_mask = stm32h7_spi_get_bpw_mask,
|
|
.disable = stm32h7_spi_disable,
|
|
.config = stm32h7_spi_config,
|
|
.set_bpw = stm32h7_spi_set_bpw,
|
|
.set_mode = stm32h7_spi_set_mode,
|
|
.set_data_idleness = stm32h7_spi_data_idleness,
|
|
.set_number_of_data = stm32h7_spi_number_of_data,
|
|
.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
|
|
.dma_rx_cb = stm32h7_spi_dma_cb,
|
|
.dma_tx_cb = stm32h7_spi_dma_cb,
|
|
.transfer_one_irq = stm32h7_spi_transfer_one_irq,
|
|
.irq_handler_thread = stm32h7_spi_irq_thread,
|
|
.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
|
|
.baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
|
|
.has_fifo = true,
|
|
};
|
|
|
|
static const struct of_device_id stm32_spi_of_match[] = {
|
|
{ .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg },
|
|
{ .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, stm32_spi_of_match);
|
|
|
|
static int stm32_spi_probe(struct platform_device *pdev)
|
|
{
|
|
struct spi_master *master;
|
|
struct stm32_spi *spi;
|
|
struct resource *res;
|
|
int i, ret;
|
|
|
|
master = spi_alloc_master(&pdev->dev, sizeof(struct stm32_spi));
|
|
if (!master) {
|
|
dev_err(&pdev->dev, "spi master allocation failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
platform_set_drvdata(pdev, master);
|
|
|
|
spi = spi_master_get_devdata(master);
|
|
spi->dev = &pdev->dev;
|
|
spi->master = master;
|
|
spin_lock_init(&spi->lock);
|
|
|
|
spi->cfg = (const struct stm32_spi_cfg *)
|
|
of_match_device(pdev->dev.driver->of_match_table,
|
|
&pdev->dev)->data;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
spi->base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(spi->base)) {
|
|
ret = PTR_ERR(spi->base);
|
|
goto err_master_put;
|
|
}
|
|
|
|
spi->phys_addr = (dma_addr_t)res->start;
|
|
|
|
spi->irq = platform_get_irq(pdev, 0);
|
|
if (spi->irq <= 0) {
|
|
ret = spi->irq;
|
|
if (ret != -EPROBE_DEFER)
|
|
dev_err(&pdev->dev, "failed to get irq: %d\n", ret);
|
|
goto err_master_put;
|
|
}
|
|
ret = devm_request_threaded_irq(&pdev->dev, spi->irq,
|
|
spi->cfg->irq_handler_event,
|
|
spi->cfg->irq_handler_thread,
|
|
IRQF_ONESHOT, pdev->name, master);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq,
|
|
ret);
|
|
goto err_master_put;
|
|
}
|
|
|
|
spi->clk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(spi->clk)) {
|
|
ret = PTR_ERR(spi->clk);
|
|
dev_err(&pdev->dev, "clk get failed: %d\n", ret);
|
|
goto err_master_put;
|
|
}
|
|
|
|
ret = clk_prepare_enable(spi->clk);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "clk enable failed: %d\n", ret);
|
|
goto err_master_put;
|
|
}
|
|
spi->clk_rate = clk_get_rate(spi->clk);
|
|
if (!spi->clk_rate) {
|
|
dev_err(&pdev->dev, "clk rate = 0\n");
|
|
ret = -EINVAL;
|
|
goto err_clk_disable;
|
|
}
|
|
|
|
spi->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
|
|
if (!IS_ERR(spi->rst)) {
|
|
reset_control_assert(spi->rst);
|
|
udelay(2);
|
|
reset_control_deassert(spi->rst);
|
|
}
|
|
|
|
if (spi->cfg->has_fifo)
|
|
spi->fifo_size = spi->cfg->get_fifo_size(spi);
|
|
|
|
ret = spi->cfg->config(spi);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "controller configuration failed: %d\n",
|
|
ret);
|
|
goto err_clk_disable;
|
|
}
|
|
|
|
master->dev.of_node = pdev->dev.of_node;
|
|
master->auto_runtime_pm = true;
|
|
master->bus_num = pdev->id;
|
|
master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
|
|
SPI_3WIRE;
|
|
master->bits_per_word_mask = spi->cfg->get_bpw_mask(spi);
|
|
master->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min;
|
|
master->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max;
|
|
master->setup = stm32_spi_setup;
|
|
master->prepare_message = stm32_spi_prepare_msg;
|
|
master->transfer_one = stm32_spi_transfer_one;
|
|
master->unprepare_message = stm32_spi_unprepare_msg;
|
|
|
|
spi->dma_tx = dma_request_slave_channel(spi->dev, "tx");
|
|
if (!spi->dma_tx)
|
|
dev_warn(&pdev->dev, "failed to request tx dma channel\n");
|
|
else
|
|
master->dma_tx = spi->dma_tx;
|
|
|
|
spi->dma_rx = dma_request_slave_channel(spi->dev, "rx");
|
|
if (!spi->dma_rx)
|
|
dev_warn(&pdev->dev, "failed to request rx dma channel\n");
|
|
else
|
|
master->dma_rx = spi->dma_rx;
|
|
|
|
if (spi->dma_tx || spi->dma_rx)
|
|
master->can_dma = stm32_spi_can_dma;
|
|
|
|
pm_runtime_set_active(&pdev->dev);
|
|
pm_runtime_enable(&pdev->dev);
|
|
|
|
ret = devm_spi_register_master(&pdev->dev, master);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "spi master registration failed: %d\n",
|
|
ret);
|
|
goto err_dma_release;
|
|
}
|
|
|
|
if (!master->cs_gpios) {
|
|
dev_err(&pdev->dev, "no CS gpios available\n");
|
|
ret = -EINVAL;
|
|
goto err_dma_release;
|
|
}
|
|
|
|
for (i = 0; i < master->num_chipselect; i++) {
|
|
if (!gpio_is_valid(master->cs_gpios[i])) {
|
|
dev_err(&pdev->dev, "%i is not a valid gpio\n",
|
|
master->cs_gpios[i]);
|
|
ret = -EINVAL;
|
|
goto err_dma_release;
|
|
}
|
|
|
|
ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
|
|
DRIVER_NAME);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "can't get CS gpio %i\n",
|
|
master->cs_gpios[i]);
|
|
goto err_dma_release;
|
|
}
|
|
}
|
|
|
|
dev_info(&pdev->dev, "driver initialized\n");
|
|
|
|
return 0;
|
|
|
|
err_dma_release:
|
|
if (spi->dma_tx)
|
|
dma_release_channel(spi->dma_tx);
|
|
if (spi->dma_rx)
|
|
dma_release_channel(spi->dma_rx);
|
|
|
|
pm_runtime_disable(&pdev->dev);
|
|
err_clk_disable:
|
|
clk_disable_unprepare(spi->clk);
|
|
err_master_put:
|
|
spi_master_put(master);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_spi_remove(struct platform_device *pdev)
|
|
{
|
|
struct spi_master *master = platform_get_drvdata(pdev);
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
|
|
spi->cfg->disable(spi);
|
|
|
|
if (master->dma_tx)
|
|
dma_release_channel(master->dma_tx);
|
|
if (master->dma_rx)
|
|
dma_release_channel(master->dma_rx);
|
|
|
|
clk_disable_unprepare(spi->clk);
|
|
|
|
pm_runtime_disable(&pdev->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int stm32_spi_runtime_suspend(struct device *dev)
|
|
{
|
|
struct spi_master *master = dev_get_drvdata(dev);
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
|
|
clk_disable_unprepare(spi->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_spi_runtime_resume(struct device *dev)
|
|
{
|
|
struct spi_master *master = dev_get_drvdata(dev);
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
|
|
return clk_prepare_enable(spi->clk);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int stm32_spi_suspend(struct device *dev)
|
|
{
|
|
struct spi_master *master = dev_get_drvdata(dev);
|
|
int ret;
|
|
|
|
ret = spi_master_suspend(master);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return pm_runtime_force_suspend(dev);
|
|
}
|
|
|
|
static int stm32_spi_resume(struct device *dev)
|
|
{
|
|
struct spi_master *master = dev_get_drvdata(dev);
|
|
struct stm32_spi *spi = spi_master_get_devdata(master);
|
|
int ret;
|
|
|
|
ret = pm_runtime_force_resume(dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = spi_master_resume(master);
|
|
if (ret)
|
|
clk_disable_unprepare(spi->clk);
|
|
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops stm32_spi_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(stm32_spi_suspend, stm32_spi_resume)
|
|
SET_RUNTIME_PM_OPS(stm32_spi_runtime_suspend,
|
|
stm32_spi_runtime_resume, NULL)
|
|
};
|
|
|
|
static struct platform_driver stm32_spi_driver = {
|
|
.probe = stm32_spi_probe,
|
|
.remove = stm32_spi_remove,
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.pm = &stm32_spi_pm_ops,
|
|
.of_match_table = stm32_spi_of_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(stm32_spi_driver);
|
|
|
|
MODULE_ALIAS("platform:" DRIVER_NAME);
|
|
MODULE_DESCRIPTION("STMicroelectronics STM32 SPI Controller driver");
|
|
MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
|
|
MODULE_LICENSE("GPL v2");
|