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linux/drivers/spi/spi-stm32.c
Ben Wolsieffer 52b62e7a5d
spi: stm32: enable controller before asserting CS 
On the STM32F4/7, the MOSI and CLK pins float while the controller is
disabled. CS is a regular GPIO, and therefore always driven. Currently,
the controller is enabled in the transfer_one() callback, which runs
after CS is asserted.  Therefore, there is a period where the SPI pins
are floating while CS is asserted, making it possible for stray signals
to disrupt communications. An analogous problem occurs at the end of the
transfer when the controller is disabled before CS is released.

This problem can be reliably observed by enabling the pull-up (if
CPOL=0) or pull-down (if CPOL=1) on the clock pin. This will cause two
extra unintended clock edges per transfer, when the controller is
enabled and disabled.

Note that this bug is likely not present on the STM32H7, because this
driver sets the AFCNTR bit (not supported on F4/F7), which keeps the SPI
pins driven even while the controller is disabled.

Enabling/disabling the controller as part of runtime PM was suggested as
an alternative approach, but this breaks the driver on the STM32MP1 (see
[1]). The following quote from the manual may explain this:

> To restart the internal state machine properly, SPI is strongly
> suggested to be disabled and re-enabled before next transaction starts
> despite its setting is not changed.

This patch has been tested on an STM32F746 with a MAX14830 UART
expander.

[1] https://lore.kernel.org/lkml/ZXzRi_h2AMqEhMVw@dell-precision-5540/T/

Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Link: https://lore.kernel.org/r/20240424135237.1329001-2-ben.wolsieffer@hefring.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2024-05-03 11:07:41 +09:00

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// SPDX-License-Identifier: GPL-2.0
//
// STMicroelectronics STM32 SPI Controller driver
//
// Copyright (C) 2017, STMicroelectronics - All Rights Reserved
// Author(s): Amelie Delaunay <amelie.delaunay@st.com> for STMicroelectronics.
#include <linux/bitfield.h>
#include <linux/debugfs.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/spi/spi.h>
#define DRIVER_NAME "spi_stm32"
/* STM32F4/7 SPI registers */
#define STM32FX_SPI_CR1 0x00
#define STM32FX_SPI_CR2 0x04
#define STM32FX_SPI_SR 0x08
#define STM32FX_SPI_DR 0x0C
#define STM32FX_SPI_I2SCFGR 0x1C
/* STM32FX_SPI_CR1 bit fields */
#define STM32FX_SPI_CR1_CPHA BIT(0)
#define STM32FX_SPI_CR1_CPOL BIT(1)
#define STM32FX_SPI_CR1_MSTR BIT(2)
#define STM32FX_SPI_CR1_BR_SHIFT 3
#define STM32FX_SPI_CR1_BR GENMASK(5, 3)
#define STM32FX_SPI_CR1_SPE BIT(6)
#define STM32FX_SPI_CR1_LSBFRST BIT(7)
#define STM32FX_SPI_CR1_SSI BIT(8)
#define STM32FX_SPI_CR1_SSM BIT(9)
#define STM32FX_SPI_CR1_RXONLY BIT(10)
#define STM32F4_SPI_CR1_DFF BIT(11)
#define STM32F7_SPI_CR1_CRCL BIT(11)
#define STM32FX_SPI_CR1_CRCNEXT BIT(12)
#define STM32FX_SPI_CR1_CRCEN BIT(13)
#define STM32FX_SPI_CR1_BIDIOE BIT(14)
#define STM32FX_SPI_CR1_BIDIMODE BIT(15)
#define STM32FX_SPI_CR1_BR_MIN 0
#define STM32FX_SPI_CR1_BR_MAX (GENMASK(5, 3) >> 3)
/* STM32FX_SPI_CR2 bit fields */
#define STM32FX_SPI_CR2_RXDMAEN BIT(0)
#define STM32FX_SPI_CR2_TXDMAEN BIT(1)
#define STM32FX_SPI_CR2_SSOE BIT(2)
#define STM32FX_SPI_CR2_FRF BIT(4)
#define STM32FX_SPI_CR2_ERRIE BIT(5)
#define STM32FX_SPI_CR2_RXNEIE BIT(6)
#define STM32FX_SPI_CR2_TXEIE BIT(7)
#define STM32F7_SPI_CR2_DS GENMASK(11, 8)
#define STM32F7_SPI_CR2_FRXTH BIT(12)
#define STM32F7_SPI_CR2_LDMA_RX BIT(13)
#define STM32F7_SPI_CR2_LDMA_TX BIT(14)
/* STM32FX_SPI_SR bit fields */
#define STM32FX_SPI_SR_RXNE BIT(0)
#define STM32FX_SPI_SR_TXE BIT(1)
#define STM32FX_SPI_SR_CHSIDE BIT(2)
#define STM32FX_SPI_SR_UDR BIT(3)
#define STM32FX_SPI_SR_CRCERR BIT(4)
#define STM32FX_SPI_SR_MODF BIT(5)
#define STM32FX_SPI_SR_OVR BIT(6)
#define STM32FX_SPI_SR_BSY BIT(7)
#define STM32FX_SPI_SR_FRE BIT(8)
#define STM32F7_SPI_SR_FRLVL GENMASK(10, 9)
#define STM32F7_SPI_SR_FTLVL GENMASK(12, 11)
/* STM32FX_SPI_I2SCFGR bit fields */
#define STM32FX_SPI_I2SCFGR_I2SMOD BIT(11)
/* STM32F4 SPI Baud Rate min/max divisor */
#define STM32FX_SPI_BR_DIV_MIN (2 << STM32FX_SPI_CR1_BR_MIN)
#define STM32FX_SPI_BR_DIV_MAX (2 << STM32FX_SPI_CR1_BR_MAX)
/* STM32H7 SPI registers */
#define STM32H7_SPI_CR1 0x00
#define STM32H7_SPI_CR2 0x04
#define STM32H7_SPI_CFG1 0x08
#define STM32H7_SPI_CFG2 0x0C
#define STM32H7_SPI_IER 0x10
#define STM32H7_SPI_SR 0x14
#define STM32H7_SPI_IFCR 0x18
#define STM32H7_SPI_TXDR 0x20
#define STM32H7_SPI_RXDR 0x30
#define STM32H7_SPI_I2SCFGR 0x50
/* STM32H7_SPI_CR1 bit fields */
#define STM32H7_SPI_CR1_SPE BIT(0)
#define STM32H7_SPI_CR1_MASRX BIT(8)
#define STM32H7_SPI_CR1_CSTART BIT(9)
#define STM32H7_SPI_CR1_CSUSP BIT(10)
#define STM32H7_SPI_CR1_HDDIR BIT(11)
#define STM32H7_SPI_CR1_SSI BIT(12)
/* STM32H7_SPI_CR2 bit fields */
#define STM32H7_SPI_CR2_TSIZE GENMASK(15, 0)
#define STM32H7_SPI_TSIZE_MAX GENMASK(15, 0)
/* STM32H7_SPI_CFG1 bit fields */
#define STM32H7_SPI_CFG1_DSIZE GENMASK(4, 0)
#define STM32H7_SPI_CFG1_FTHLV GENMASK(8, 5)
#define STM32H7_SPI_CFG1_RXDMAEN BIT(14)
#define STM32H7_SPI_CFG1_TXDMAEN BIT(15)
#define STM32H7_SPI_CFG1_MBR GENMASK(30, 28)
#define STM32H7_SPI_CFG1_MBR_SHIFT 28
#define STM32H7_SPI_CFG1_MBR_MIN 0
#define STM32H7_SPI_CFG1_MBR_MAX (GENMASK(30, 28) >> 28)
/* STM32H7_SPI_CFG2 bit fields */
#define STM32H7_SPI_CFG2_MIDI GENMASK(7, 4)
#define STM32H7_SPI_CFG2_COMM GENMASK(18, 17)
#define STM32H7_SPI_CFG2_SP GENMASK(21, 19)
#define STM32H7_SPI_CFG2_MASTER BIT(22)
#define STM32H7_SPI_CFG2_LSBFRST BIT(23)
#define STM32H7_SPI_CFG2_CPHA BIT(24)
#define STM32H7_SPI_CFG2_CPOL BIT(25)
#define STM32H7_SPI_CFG2_SSM BIT(26)
#define STM32H7_SPI_CFG2_SSIOP BIT(28)
#define STM32H7_SPI_CFG2_AFCNTR BIT(31)
/* STM32H7_SPI_IER bit fields */
#define STM32H7_SPI_IER_RXPIE BIT(0)
#define STM32H7_SPI_IER_TXPIE BIT(1)
#define STM32H7_SPI_IER_DXPIE BIT(2)
#define STM32H7_SPI_IER_EOTIE BIT(3)
#define STM32H7_SPI_IER_TXTFIE BIT(4)
#define STM32H7_SPI_IER_OVRIE BIT(6)
#define STM32H7_SPI_IER_MODFIE BIT(9)
#define STM32H7_SPI_IER_ALL GENMASK(10, 0)
/* STM32H7_SPI_SR bit fields */
#define STM32H7_SPI_SR_RXP BIT(0)
#define STM32H7_SPI_SR_TXP BIT(1)
#define STM32H7_SPI_SR_EOT BIT(3)
#define STM32H7_SPI_SR_OVR BIT(6)
#define STM32H7_SPI_SR_MODF BIT(9)
#define STM32H7_SPI_SR_SUSP BIT(11)
#define STM32H7_SPI_SR_RXPLVL GENMASK(14, 13)
#define STM32H7_SPI_SR_RXWNE BIT(15)
/* STM32H7_SPI_IFCR bit fields */
#define STM32H7_SPI_IFCR_ALL GENMASK(11, 3)
/* STM32H7_SPI_I2SCFGR bit fields */
#define STM32H7_SPI_I2SCFGR_I2SMOD BIT(0)
/* STM32MP25 SPI registers bit fields */
#define STM32MP25_SPI_HWCFGR1 0x3F0
/* STM32MP25_SPI_CR2 bit fields */
#define STM32MP25_SPI_TSIZE_MAX_LIMITED GENMASK(9, 0)
/* STM32MP25_SPI_HWCFGR1 */
#define STM32MP25_SPI_HWCFGR1_FULLCFG GENMASK(27, 24)
#define STM32MP25_SPI_HWCFGR1_FULLCFG_LIMITED 0x0
#define STM32MP25_SPI_HWCFGR1_FULLCFG_FULL 0x1
#define STM32MP25_SPI_HWCFGR1_DSCFG GENMASK(19, 16)
#define STM32MP25_SPI_HWCFGR1_DSCFG_16_B 0x0
#define STM32MP25_SPI_HWCFGR1_DSCFG_32_B 0x1
/* STM32H7 SPI Master Baud Rate min/max divisor */
#define STM32H7_SPI_MBR_DIV_MIN (2 << STM32H7_SPI_CFG1_MBR_MIN)
#define STM32H7_SPI_MBR_DIV_MAX (2 << STM32H7_SPI_CFG1_MBR_MAX)
/* STM32H7 SPI Communication mode */
#define STM32H7_SPI_FULL_DUPLEX 0
#define STM32H7_SPI_SIMPLEX_TX 1
#define STM32H7_SPI_SIMPLEX_RX 2
#define STM32H7_SPI_HALF_DUPLEX 3
/* SPI Communication type */
#define SPI_FULL_DUPLEX 0
#define SPI_SIMPLEX_TX 1
#define SPI_SIMPLEX_RX 2
#define SPI_3WIRE_TX 3
#define SPI_3WIRE_RX 4
#define STM32_SPI_AUTOSUSPEND_DELAY 1 /* 1 ms */
/*
* use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers
* without fifo buffers.
*/
#define SPI_DMA_MIN_BYTES 16
/* STM32 SPI driver helpers */
#define STM32_SPI_HOST_MODE(stm32_spi) (!(stm32_spi)->device_mode)
#define STM32_SPI_DEVICE_MODE(stm32_spi) ((stm32_spi)->device_mode)
/**
* struct stm32_spi_reg - stm32 SPI register & bitfield desc
* @reg: register offset
* @mask: bitfield mask
* @shift: left shift
*/
struct stm32_spi_reg {
int reg;
int mask;
int shift;
};
/**
* struct stm32_spi_regspec - stm32 registers definition, compatible dependent data
* @en: enable register and SPI enable bit
* @dma_rx_en: SPI DMA RX enable register end SPI DMA RX enable bit
* @dma_tx_en: SPI DMA TX enable register end SPI DMA TX enable bit
* @cpol: clock polarity register and polarity bit
* @cpha: clock phase register and phase bit
* @lsb_first: LSB transmitted first register and bit
* @cs_high: chips select active value
* @br: baud rate register and bitfields
* @rx: SPI RX data register
* @tx: SPI TX data register
* @fullcfg: SPI full or limited feature set register
*/
struct stm32_spi_regspec {
const struct stm32_spi_reg en;
const struct stm32_spi_reg dma_rx_en;
const struct stm32_spi_reg dma_tx_en;
const struct stm32_spi_reg cpol;
const struct stm32_spi_reg cpha;
const struct stm32_spi_reg lsb_first;
const struct stm32_spi_reg cs_high;
const struct stm32_spi_reg br;
const struct stm32_spi_reg rx;
const struct stm32_spi_reg tx;
const struct stm32_spi_reg fullcfg;
};
struct stm32_spi;
/**
* struct stm32_spi_cfg - stm32 compatible configuration data
* @regs: registers descriptions
* @get_fifo_size: routine to get fifo size
* @get_bpw_mask: routine to get bits per word mask
* @disable: routine to disable controller
* @config: routine to configure controller as SPI Host
* @set_bpw: routine to configure registers to for bits per word
* @set_mode: routine to configure registers to desired mode
* @set_data_idleness: optional routine to configure registers to desired idle
* time between frames (if driver has this functionality)
* @set_number_of_data: optional routine to configure registers to desired
* number of data (if driver has this functionality)
* @write_tx: routine to write to transmit register/FIFO
* @read_rx: routine to read from receive register/FIFO
* @transfer_one_dma_start: routine to start transfer a single spi_transfer
* using DMA
* @dma_rx_cb: routine to call after DMA RX channel operation is complete
* @dma_tx_cb: routine to call after DMA TX channel operation is complete
* @transfer_one_irq: routine to configure interrupts for driver
* @irq_handler_event: Interrupt handler for SPI controller events
* @irq_handler_thread: thread of interrupt handler for SPI controller
* @baud_rate_div_min: minimum baud rate divisor
* @baud_rate_div_max: maximum baud rate divisor
* @has_fifo: boolean to know if fifo is used for driver
* @has_device_mode: is this compatible capable to switch on device mode
* @flags: compatible specific SPI controller flags used at registration time
* @prevent_dma_burst: boolean to indicate to prevent DMA burst
*/
struct stm32_spi_cfg {
const struct stm32_spi_regspec *regs;
int (*get_fifo_size)(struct stm32_spi *spi);
int (*get_bpw_mask)(struct stm32_spi *spi);
void (*disable)(struct stm32_spi *spi);
int (*config)(struct stm32_spi *spi);
void (*set_bpw)(struct stm32_spi *spi);
int (*set_mode)(struct stm32_spi *spi, unsigned int comm_type);
void (*set_data_idleness)(struct stm32_spi *spi, u32 length);
int (*set_number_of_data)(struct stm32_spi *spi, u32 length);
void (*write_tx)(struct stm32_spi *spi);
void (*read_rx)(struct stm32_spi *spi);
void (*transfer_one_dma_start)(struct stm32_spi *spi);
void (*dma_rx_cb)(void *data);
void (*dma_tx_cb)(void *data);
int (*transfer_one_irq)(struct stm32_spi *spi);
irqreturn_t (*irq_handler_event)(int irq, void *dev_id);
irqreturn_t (*irq_handler_thread)(int irq, void *dev_id);
unsigned int baud_rate_div_min;
unsigned int baud_rate_div_max;
bool has_fifo;
bool has_device_mode;
u16 flags;
bool prevent_dma_burst;
};
/**
* struct stm32_spi - private data of the SPI controller
* @dev: driver model representation of the controller
* @ctrl: controller interface
* @cfg: compatible configuration data
* @base: virtual memory area
* @clk: hw kernel clock feeding the SPI clock generator
* @clk_rate: rate of the hw kernel clock feeding the SPI clock generator
* @lock: prevent I/O concurrent access
* @irq: SPI controller interrupt line
* @fifo_size: size of the embedded fifo in bytes
* @t_size_max: maximum number of data of one transfer
* @feature_set: SPI full or limited feature set
* @cur_midi: host inter-data idleness in ns
* @cur_speed: speed configured in Hz
* @cur_half_period: time of a half bit in us
* @cur_bpw: number of bits in a single SPI data frame
* @cur_fthlv: fifo threshold level (data frames in a single data packet)
* @cur_comm: SPI communication mode
* @cur_xferlen: current transfer length in bytes
* @cur_usedma: boolean to know if dma is used in current transfer
* @tx_buf: data to be written, or NULL
* @rx_buf: data to be read, or NULL
* @tx_len: number of data to be written in bytes
* @rx_len: number of data to be read in bytes
* @dma_tx: dma channel for TX transfer
* @dma_rx: dma channel for RX transfer
* @phys_addr: SPI registers physical base address
* @device_mode: the controller is configured as SPI device
*/
struct stm32_spi {
struct device *dev;
struct spi_controller *ctrl;
const struct stm32_spi_cfg *cfg;
void __iomem *base;
struct clk *clk;
u32 clk_rate;
spinlock_t lock; /* prevent I/O concurrent access */
int irq;
unsigned int fifo_size;
unsigned int t_size_max;
unsigned int feature_set;
#define STM32_SPI_FEATURE_LIMITED STM32MP25_SPI_HWCFGR1_FULLCFG_LIMITED /* 0x0 */
#define STM32_SPI_FEATURE_FULL STM32MP25_SPI_HWCFGR1_FULLCFG_FULL /* 0x1 */
unsigned int cur_midi;
unsigned int cur_speed;
unsigned int cur_half_period;
unsigned int cur_bpw;
unsigned int cur_fthlv;
unsigned int cur_comm;
unsigned int cur_xferlen;
bool cur_usedma;
const void *tx_buf;
void *rx_buf;
int tx_len;
int rx_len;
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
dma_addr_t phys_addr;
bool device_mode;
};
static const struct stm32_spi_regspec stm32fx_spi_regspec = {
.en = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_SPE },
.dma_rx_en = { STM32FX_SPI_CR2, STM32FX_SPI_CR2_RXDMAEN },
.dma_tx_en = { STM32FX_SPI_CR2, STM32FX_SPI_CR2_TXDMAEN },
.cpol = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_CPOL },
.cpha = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_CPHA },
.lsb_first = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_LSBFRST },
.cs_high = {},
.br = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_BR, STM32FX_SPI_CR1_BR_SHIFT },
.rx = { STM32FX_SPI_DR },
.tx = { STM32FX_SPI_DR },
};
static const struct stm32_spi_regspec stm32h7_spi_regspec = {
/* SPI data transfer is enabled but spi_ker_ck is idle.
* CFG1 and CFG2 registers are write protected when SPE is enabled.
*/
.en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
.dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
.dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
.cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
.cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
.lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
.cs_high = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_SSIOP },
.br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
STM32H7_SPI_CFG1_MBR_SHIFT },
.rx = { STM32H7_SPI_RXDR },
.tx = { STM32H7_SPI_TXDR },
};
static const struct stm32_spi_regspec stm32mp25_spi_regspec = {
/* SPI data transfer is enabled but spi_ker_ck is idle.
* CFG1 and CFG2 registers are write protected when SPE is enabled.
*/
.en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
.dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
.dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
.cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
.cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
.lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
.cs_high = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_SSIOP },
.br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
STM32H7_SPI_CFG1_MBR_SHIFT },
.rx = { STM32H7_SPI_RXDR },
.tx = { STM32H7_SPI_TXDR },
.fullcfg = { STM32MP25_SPI_HWCFGR1, STM32MP25_SPI_HWCFGR1_FULLCFG },
};
static inline void stm32_spi_set_bits(struct stm32_spi *spi,
u32 offset, u32 bits)
{
writel_relaxed(readl_relaxed(spi->base + offset) | bits,
spi->base + offset);
}
static inline void stm32_spi_clr_bits(struct stm32_spi *spi,
u32 offset, u32 bits)
{
writel_relaxed(readl_relaxed(spi->base + offset) & ~bits,
spi->base + offset);
}
/**
* stm32h7_spi_get_fifo_size - Return fifo size
* @spi: pointer to the spi controller data structure
*/
static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi)
{
unsigned long flags;
u32 count = 0;
spin_lock_irqsave(&spi->lock, flags);
stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
while (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP)
writeb_relaxed(++count, spi->base + STM32H7_SPI_TXDR);
stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
spin_unlock_irqrestore(&spi->lock, flags);
dev_dbg(spi->dev, "%d x 8-bit fifo size\n", count);
return count;
}
/**
* stm32f4_spi_get_bpw_mask - Return bits per word mask
* @spi: pointer to the spi controller data structure
*/
static int stm32f4_spi_get_bpw_mask(struct stm32_spi *spi)
{
dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
}
/**
* stm32f7_spi_get_bpw_mask - Return bits per word mask
* @spi: pointer to the spi controller data structure
*/
static int stm32f7_spi_get_bpw_mask(struct stm32_spi *spi)
{
dev_dbg(spi->dev, "16-bit maximum data frame\n");
return SPI_BPW_RANGE_MASK(4, 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 = FIELD_GET(STM32H7_SPI_CFG1_DSIZE, cfg1) + 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);
}
/**
* stm32mp25_spi_get_bpw_mask - Return bits per word mask
* @spi: pointer to the spi controller data structure
*/
static int stm32mp25_spi_get_bpw_mask(struct stm32_spi *spi)
{
u32 dscfg, max_bpw;
if (spi->feature_set == STM32_SPI_FEATURE_LIMITED) {
dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
}
dscfg = FIELD_GET(STM32MP25_SPI_HWCFGR1_DSCFG,
readl_relaxed(spi->base + STM32MP25_SPI_HWCFGR1));
max_bpw = 16;
if (dscfg == STM32MP25_SPI_HWCFGR1_DSCFG_32_B)
max_bpw = 32;
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;
/* Ensure spi->clk_rate is even */
div = DIV_ROUND_CLOSEST(spi->clk_rate & ~0x1, speed_hz);
/*
* SPI framework set xfer->speed_hz to ctrl->max_speed_hz if
* xfer->speed_hz is greater than ctrl->max_speed_hz, and it returns
* an error when xfer->speed_hz is lower than ctrl->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);
spi->cur_half_period = DIV_ROUND_CLOSEST(USEC_PER_SEC, 2 * spi->cur_speed);
return mbrdiv - 1;
}
/**
* stm32h7_spi_prepare_fthlv - Determine FIFO threshold level
* @spi: pointer to the spi controller data structure
* @xfer_len: length of the message to be transferred
*/
static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len)
{
u32 packet, bpw;
/* data packet should not exceed 1/2 of fifo space */
packet = clamp(xfer_len, 1U, spi->fifo_size / 2);
/* align packet size with data registers access */
bpw = DIV_ROUND_UP(spi->cur_bpw, 8);
return DIV_ROUND_UP(packet, bpw);
}
/**
* 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 + STM32FX_SPI_SR) &
STM32FX_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 + STM32FX_SPI_DR);
spi->tx_len -= sizeof(u16);
} else {
const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
writeb_relaxed(*tx_buf8, spi->base + STM32FX_SPI_DR);
spi->tx_len -= sizeof(u8);
}
}
dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
}
/**
* stm32f7_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 stm32f7_spi_write_tx(struct stm32_spi *spi)
{
if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32FX_SPI_SR) &
STM32FX_SPI_SR_TXE)) {
u32 offs = spi->cur_xferlen - spi->tx_len;
if (spi->tx_len >= sizeof(u16)) {
const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
writew_relaxed(*tx_buf16, spi->base + STM32FX_SPI_DR);
spi->tx_len -= sizeof(u16);
} else {
const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
writeb_relaxed(*tx_buf8, spi->base + STM32FX_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 + STM32FX_SPI_SR) &
STM32FX_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 + STM32FX_SPI_DR);
spi->rx_len -= sizeof(u16);
} else {
u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
*rx_buf8 = readb_relaxed(spi->base + STM32FX_SPI_DR);
spi->rx_len -= sizeof(u8);
}
}
dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->rx_len);
}
/**
* stm32f7_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 stm32f7_spi_read_rx(struct stm32_spi *spi)
{
u32 sr = readl_relaxed(spi->base + STM32FX_SPI_SR);
u32 frlvl = FIELD_GET(STM32F7_SPI_SR_FRLVL, sr);
while ((spi->rx_len > 0) && (frlvl > 0)) {
u32 offs = spi->cur_xferlen - spi->rx_len;
if ((spi->rx_len >= sizeof(u16)) && (frlvl >= 2)) {
u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
*rx_buf16 = readw_relaxed(spi->base + STM32FX_SPI_DR);
spi->rx_len -= sizeof(u16);
} else {
u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
*rx_buf8 = readb_relaxed(spi->base + STM32FX_SPI_DR);
spi->rx_len -= sizeof(u8);
}
sr = readl_relaxed(spi->base + STM32FX_SPI_SR);
frlvl = FIELD_GET(STM32F7_SPI_SR_FRLVL, sr);
}
if (spi->rx_len >= sizeof(u16))
stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
else
stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n",
__func__, spi->rx_len, sr);
}
/**
* 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)
{
u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
u32 rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
while ((spi->rx_len > 0) &&
((sr & STM32H7_SPI_SR_RXP) ||
((sr & STM32H7_SPI_SR_EOT) &&
((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) {
u32 offs = spi->cur_xferlen - spi->rx_len;
if ((spi->rx_len >= sizeof(u32)) ||
(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)) ||
(!(sr & STM32H7_SPI_SR_RXWNE) &&
(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 = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
}
dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n",
__func__, spi->rx_len, sr);
}
/**
* 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);
}
/**
* stm32fx_spi_disable - Disable SPI controller
* @spi: pointer to the spi controller data structure
*/
static void stm32fx_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 + STM32FX_SPI_CR1) &
STM32FX_SPI_CR1_SPE)) {
spin_unlock_irqrestore(&spi->lock, flags);
return;
}
/* Disable interrupts */
stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_TXEIE |
STM32FX_SPI_CR2_RXNEIE |
STM32FX_SPI_CR2_ERRIE);
/* Wait until BSY = 0 */
if (readl_relaxed_poll_timeout_atomic(spi->base + STM32FX_SPI_SR,
sr, !(sr & STM32FX_SPI_SR_BSY),
10, 100000) < 0) {
dev_warn(spi->dev, "disabling condition timeout\n");
}
if (spi->cur_usedma && spi->dma_tx)
dmaengine_terminate_async(spi->dma_tx);
if (spi->cur_usedma && spi->dma_rx)
dmaengine_terminate_async(spi->dma_rx);
stm32_spi_clr_bits(spi, STM32FX_SPI_CR1, STM32FX_SPI_CR1_SPE);
stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_TXDMAEN |
STM32FX_SPI_CR2_RXDMAEN);
/* Sequence to clear OVR flag */
readl_relaxed(spi->base + STM32FX_SPI_DR);
readl_relaxed(spi->base + STM32FX_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.
*/
static void stm32h7_spi_disable(struct stm32_spi *spi)
{
unsigned long flags;
u32 cr1;
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;
}
/* Add a delay to make sure that transmission is ended. */
if (spi->cur_half_period)
udelay(spi->cur_half_period);
if (spi->cur_usedma && spi->dma_tx)
dmaengine_terminate_async(spi->dma_tx);
if (spi->cur_usedma && spi->dma_rx)
dmaengine_terminate_async(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
* @ctrl: controller interface
* @spi_dev: pointer to the spi device
* @transfer: pointer to spi transfer
*
* 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_controller *ctrl,
struct spi_device *spi_dev,
struct spi_transfer *transfer)
{
unsigned int dma_size;
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
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);
}
/**
* stm32fx_spi_irq_event - Interrupt handler for SPI controller events
* @irq: interrupt line
* @dev_id: SPI controller ctrl interface
*/
static irqreturn_t stm32fx_spi_irq_event(int irq, void *dev_id)
{
struct spi_controller *ctrl = dev_id;
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
u32 sr, mask = 0;
bool end = false;
spin_lock(&spi->lock);
sr = readl_relaxed(spi->base + STM32FX_SPI_SR);
/*
* BSY flag is not handled in interrupt but it is normal behavior when
* this flag is set.
*/
sr &= ~STM32FX_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 &= ~(STM32FX_SPI_SR_OVR | STM32FX_SPI_SR_RXNE);
mask |= STM32FX_SPI_SR_TXE;
}
if (!spi->cur_usedma && (spi->cur_comm == SPI_FULL_DUPLEX ||
spi->cur_comm == SPI_SIMPLEX_RX ||
spi->cur_comm == SPI_3WIRE_RX)) {
/* TXE flag is set and is handled when RXNE flag occurs */
sr &= ~STM32FX_SPI_SR_TXE;
mask |= STM32FX_SPI_SR_RXNE | STM32FX_SPI_SR_OVR;
}
if (!(sr & mask)) {
dev_dbg(spi->dev, "spurious IT (sr=0x%08x)\n", sr);
spin_unlock(&spi->lock);
return IRQ_NONE;
}
if (sr & STM32FX_SPI_SR_OVR) {
dev_warn(spi->dev, "Overrun: received value discarded\n");
/* Sequence to clear OVR flag */
readl_relaxed(spi->base + STM32FX_SPI_DR);
readl_relaxed(spi->base + STM32FX_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 & STM32FX_SPI_SR_TXE) {
if (spi->tx_buf)
spi->cfg->write_tx(spi);
if (spi->tx_len == 0)
end = true;
}
if (sr & STM32FX_SPI_SR_RXNE) {
spi->cfg->read_rx(spi);
if (spi->rx_len == 0)
end = true;
else if (spi->tx_buf)/* Load data for discontinuous mode */
spi->cfg->write_tx(spi);
}
end_irq:
if (end) {
/* Immediately disable interrupts to do not generate new one */
stm32_spi_clr_bits(spi, STM32FX_SPI_CR2,
STM32FX_SPI_CR2_TXEIE |
STM32FX_SPI_CR2_RXNEIE |
STM32FX_SPI_CR2_ERRIE);
spin_unlock(&spi->lock);
return IRQ_WAKE_THREAD;
}
spin_unlock(&spi->lock);
return IRQ_HANDLED;
}
/**
* stm32fx_spi_irq_thread - Thread of interrupt handler for SPI controller
* @irq: interrupt line
* @dev_id: SPI controller interface
*/
static irqreturn_t stm32fx_spi_irq_thread(int irq, void *dev_id)
{
struct spi_controller *ctrl = dev_id;
spi_finalize_current_transfer(ctrl);
return IRQ_HANDLED;
}
/**
* stm32h7_spi_irq_thread - Thread of interrupt handler for SPI controller
* @irq: interrupt line
* @dev_id: SPI controller interface
*/
static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
{
struct spi_controller *ctrl = dev_id;
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
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 enables irq from EOT, SUSP and TXC events. We need to set
* SUSP to acknowledge it later. TXC is automatically cleared
*/
mask |= STM32H7_SPI_SR_SUSP;
/*
* DXPIE is set in Full-Duplex, one IT will be raised if TXP and RXP
* are set. So in case of Full-Duplex, need to poll TXP and RXP event.
*/
if ((spi->cur_comm == SPI_FULL_DUPLEX) && !spi->cur_usedma)
mask |= STM32H7_SPI_SR_TXP | STM32H7_SPI_SR_RXP;
if (!(sr & mask)) {
dev_warn(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) {
static DEFINE_RATELIMIT_STATE(rs,
DEFAULT_RATELIMIT_INTERVAL * 10,
1);
ratelimit_set_flags(&rs, RATELIMIT_MSG_ON_RELEASE);
if (__ratelimit(&rs))
dev_dbg_ratelimited(spi->dev, "Communication suspended\n");
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
stm32h7_spi_read_rxfifo(spi);
/*
* 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_err(spi->dev, "Overrun: RX data lost\n");
end = true;
}
if (sr & STM32H7_SPI_SR_EOT) {
if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
stm32h7_spi_read_rxfifo(spi);
if (!spi->cur_usedma ||
(spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX))
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);
writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR);
spin_unlock_irqrestore(&spi->lock, flags);
if (end) {
stm32h7_spi_disable(spi);
spi_finalize_current_transfer(ctrl);
}
return IRQ_HANDLED;
}
static int stm32_spi_optimize_message(struct spi_message *msg)
{
struct spi_controller *ctrl = msg->spi->controller;
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
/* On STM32H7, messages should not exceed a maximum size set
* later via the set_number_of_data function. In order to
* ensure that, split large messages into several messages
*/
if (spi->cfg->set_number_of_data)
return spi_split_transfers_maxwords(ctrl, msg, spi->t_size_max);
return 0;
}
/**
* stm32_spi_prepare_msg - set up the controller to transfer a single message
* @ctrl: controller interface
* @msg: pointer to spi message
*/
static int stm32_spi_prepare_msg(struct spi_controller *ctrl,
struct spi_message *msg)
{
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
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 target 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;
if (STM32_SPI_DEVICE_MODE(spi) && spi_dev->mode & SPI_CS_HIGH)
setb |= spi->cfg->regs->cs_high.mask;
else
clrb |= spi->cfg->regs->cs_high.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);
stm32_spi_enable(spi);
spin_unlock_irqrestore(&spi->lock, flags);
return 0;
}
/**
* stm32fx_spi_dma_tx_cb - dma callback
* @data: pointer to the spi controller data structure
*
* DMA callback is called when the transfer is complete for DMA TX channel.
*/
static void stm32fx_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->ctrl);
}
}
/**
* stm32_spi_dma_rx_cb - dma callback
* @data: pointer to the spi controller data structure
*
* DMA callback is called when the transfer is complete for DMA RX channel.
*/
static void stm32_spi_dma_rx_cb(void *data)
{
struct stm32_spi *spi = data;
spi_finalize_current_transfer(spi->ctrl);
}
/**
* stm32_spi_dma_config - configure dma slave channel depending on current
* transfer bits_per_word.
* @spi: pointer to the spi controller data structure
* @dma_chan: pointer to the DMA channel
* @dma_conf: pointer to the dma_slave_config structure
* @dir: direction of the dma transfer
*/
static void stm32_spi_dma_config(struct stm32_spi *spi,
struct dma_chan *dma_chan,
struct dma_slave_config *dma_conf,
enum dma_transfer_direction dir)
{
enum dma_slave_buswidth buswidth;
struct dma_slave_caps caps;
u32 maxburst = 1;
int ret;
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;
/* Valid for DMA Half or Full Fifo threshold */
if (!spi->cfg->prevent_dma_burst && spi->cfg->has_fifo && spi->cur_fthlv != 2)
maxburst = spi->cur_fthlv;
/* Get the DMA channel caps, and adjust maxburst if possible */
ret = dma_get_slave_caps(dma_chan, &caps);
if (!ret)
maxburst = min(maxburst, caps.max_burst);
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);
}
}
/**
* stm32fx_spi_transfer_one_irq - transfer a single spi_transfer using
* interrupts
* @spi: pointer to the spi controller data structure
*
* It must returns 0 if the transfer is finished or 1 if the transfer is still
* in progress.
*/
static int stm32fx_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 |= STM32FX_SPI_CR2_TXEIE;
} else if (spi->cur_comm == SPI_FULL_DUPLEX ||
spi->cur_comm == SPI_SIMPLEX_RX ||
spi->cur_comm == SPI_3WIRE_RX) {
/* 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 |= STM32FX_SPI_CR2_RXNEIE | STM32FX_SPI_CR2_ERRIE;
} else {
return -EINVAL;
}
spin_lock_irqsave(&spi->lock, flags);
stm32_spi_set_bits(spi, STM32FX_SPI_CR2, cr2);
/* starting data transfer when buffer is loaded */
if (spi->tx_buf)
spi->cfg->write_tx(spi);
spin_unlock_irqrestore(&spi->lock, flags);
return 1;
}
/**
* stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using
* interrupts
* @spi: pointer to the spi controller data structure
*
* 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);
/* Be sure to have data in fifo before starting data transfer */
if (spi->tx_buf)
stm32h7_spi_write_txfifo(spi);
if (STM32_SPI_HOST_MODE(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;
}
/**
* stm32fx_spi_transfer_one_dma_start - Set SPI driver registers to start
* transfer using DMA
* @spi: pointer to the spi controller data structure
*/
static void stm32fx_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, STM32FX_SPI_CR2, STM32FX_SPI_CR2_ERRIE);
}
}
/**
* stm32f7_spi_transfer_one_dma_start - Set SPI driver registers to start
* transfer using DMA
* @spi: pointer to the spi controller data structure
*/
static void stm32f7_spi_transfer_one_dma_start(struct stm32_spi *spi)
{
/* Configure DMA request trigger threshold according to DMA width */
if (spi->cur_bpw <= 8)
stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
else
stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
stm32fx_spi_transfer_one_dma_start(spi);
}
/**
* stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start
* transfer using DMA
* @spi: pointer to the spi controller data structure
*/
static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
{
uint32_t ier = STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
/* Enable the interrupts */
if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX)
ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE;
stm32_spi_set_bits(spi, STM32H7_SPI_IER, ier);
if (STM32_SPI_HOST_MODE(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
* @spi: pointer to the spi controller data structure
* @xfer: pointer to the spi_transfer structure
*
* 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, spi->dma_rx, &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, spi->dma_tx, &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_sync(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, STM32FX_SPI_CR1, STM32F4_SPI_CR1_DFF);
else
stm32_spi_clr_bits(spi, STM32FX_SPI_CR1, STM32F4_SPI_CR1_DFF);
}
/**
* stm32f7_spi_set_bpw - Configure bits per word
* @spi: pointer to the spi controller data structure
*/
static void stm32f7_spi_set_bpw(struct stm32_spi *spi)
{
u32 bpw;
u32 cr2_clrb = 0, cr2_setb = 0;
bpw = spi->cur_bpw - 1;
cr2_clrb |= STM32F7_SPI_CR2_DS;
cr2_setb |= FIELD_PREP(STM32F7_SPI_CR2_DS, bpw);
if (spi->rx_len >= sizeof(u16))
cr2_clrb |= STM32F7_SPI_CR2_FRXTH;
else
cr2_setb |= STM32F7_SPI_CR2_FRXTH;
writel_relaxed(
(readl_relaxed(spi->base + STM32FX_SPI_CR2) &
~cr2_clrb) | cr2_setb,
spi->base + STM32FX_SPI_CR2);
}
/**
* 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 |= FIELD_PREP(STM32H7_SPI_CFG1_DSIZE, bpw);
spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen);
fthlv = spi->cur_fthlv - 1;
cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_FTHLV, 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 host 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 |= (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;
}
/**
* stm32fx_spi_set_mode - configure communication mode
* @spi: pointer to the spi controller data structure
* @comm_type: type of communication to configure
*/
static int stm32fx_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, STM32FX_SPI_CR1,
STM32FX_SPI_CR1_BIDIMODE |
STM32FX_SPI_CR1_BIDIOE);
} else if (comm_type == SPI_FULL_DUPLEX ||
comm_type == SPI_SIMPLEX_RX) {
stm32_spi_clr_bits(spi, STM32FX_SPI_CR1,
STM32FX_SPI_CR1_BIDIMODE |
STM32FX_SPI_CR1_BIDIOE);
} else if (comm_type == SPI_3WIRE_RX) {
stm32_spi_set_bits(spi, STM32FX_SPI_CR1,
STM32FX_SPI_CR1_BIDIMODE);
stm32_spi_clr_bits(spi, STM32FX_SPI_CR1,
STM32FX_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 |= FIELD_PREP(STM32H7_SPI_CFG2_COMM, mode);
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 host 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(NSEC_PER_SEC, spi->cur_speed);
u32 midi = min_t(u32,
DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
FIELD_GET(STM32H7_SPI_CFG2_MIDI,
STM32H7_SPI_CFG2_MIDI));
dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n",
sck_period_ns, midi, midi * sck_period_ns);
cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_MIDI, 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
* @nb_words: transfer length (in words)
*/
static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words)
{
if (nb_words <= spi->t_size_max) {
writel_relaxed(FIELD_PREP(STM32H7_SPI_CR2_TSIZE, nb_words),
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.
* @spi: pointer to the spi controller data structure
* @spi_dev: pointer to the spi device
* @transfer: pointer to spi transfer
*/
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;
int mbr;
spin_lock_irqsave(&spi->lock, flags);
spi->cur_xferlen = transfer->len;
spi->cur_bpw = transfer->bits_per_word;
spi->cfg->set_bpw(spi);
/* Update spi->cur_speed with real clock speed */
if (STM32_SPI_HOST_MODE(spi)) {
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);
ret = spi->cfg->set_mode(spi, comm_type);
if (ret < 0)
goto out;
spi->cur_comm = comm_type;
if (STM32_SPI_HOST_MODE(spi) && 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;
}
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);
if (STM32_SPI_HOST_MODE(spi))
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
* @ctrl: controller interface
* @spi_dev: pointer to the spi device
* @transfer: pointer to 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_controller *ctrl,
struct spi_device *spi_dev,
struct spi_transfer *transfer)
{
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
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 = (ctrl->can_dma &&
ctrl->can_dma(ctrl, 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
* @ctrl: controller interface
* @msg: pointer to the spi message
*/
static int stm32_spi_unprepare_msg(struct spi_controller *ctrl,
struct spi_message *msg)
{
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
spi->cfg->disable(spi);
return 0;
}
/**
* stm32fx_spi_config - Configure SPI controller as SPI host
* @spi: pointer to the spi controller data structure
*/
static int stm32fx_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, STM32FX_SPI_I2SCFGR,
STM32FX_SPI_I2SCFGR_I2SMOD);
/*
* - SS input value high
* - transmitter half duplex direction
* - Set the host mode (default Motorola mode)
* - Consider 1 host/n targets configuration and
* SS input value is determined by the SSI bit
*/
stm32_spi_set_bits(spi, STM32FX_SPI_CR1, STM32FX_SPI_CR1_SSI |
STM32FX_SPI_CR1_BIDIOE |
STM32FX_SPI_CR1_MSTR |
STM32FX_SPI_CR1_SSM);
spin_unlock_irqrestore(&spi->lock, flags);
return 0;
}
/**
* stm32h7_spi_config - Configure SPI controller
* @spi: pointer to the spi controller data structure
*/
static int stm32h7_spi_config(struct stm32_spi *spi)
{
unsigned long flags;
u32 cr1 = 0, cfg2 = 0;
spin_lock_irqsave(&spi->lock, flags);
/* Ensure I2SMOD bit is kept cleared */
stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR,
STM32H7_SPI_I2SCFGR_I2SMOD);
if (STM32_SPI_DEVICE_MODE(spi)) {
/* Use native device select */
cfg2 &= ~STM32H7_SPI_CFG2_SSM;
} else {
/*
* - Transmitter half duplex direction
* - Automatic communication suspend when RX-Fifo is full
* - SS input value high
*/
cr1 |= STM32H7_SPI_CR1_HDDIR | STM32H7_SPI_CR1_MASRX | STM32H7_SPI_CR1_SSI;
/*
* - Set the host mode (default Motorola mode)
* - Consider 1 host/n devices configuration and
* SS input value is determined by the SSI bit
* - keep control of all associated GPIOs
*/
cfg2 |= STM32H7_SPI_CFG2_MASTER | STM32H7_SPI_CFG2_SSM | STM32H7_SPI_CFG2_AFCNTR;
}
stm32_spi_set_bits(spi, STM32H7_SPI_CR1, cr1);
stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, cfg2);
spin_unlock_irqrestore(&spi->lock, flags);
return 0;
}
static const struct stm32_spi_cfg stm32f4_spi_cfg = {
.regs = &stm32fx_spi_regspec,
.get_bpw_mask = stm32f4_spi_get_bpw_mask,
.disable = stm32fx_spi_disable,
.config = stm32fx_spi_config,
.set_bpw = stm32f4_spi_set_bpw,
.set_mode = stm32fx_spi_set_mode,
.write_tx = stm32f4_spi_write_tx,
.read_rx = stm32f4_spi_read_rx,
.transfer_one_dma_start = stm32fx_spi_transfer_one_dma_start,
.dma_tx_cb = stm32fx_spi_dma_tx_cb,
.dma_rx_cb = stm32_spi_dma_rx_cb,
.transfer_one_irq = stm32fx_spi_transfer_one_irq,
.irq_handler_event = stm32fx_spi_irq_event,
.irq_handler_thread = stm32fx_spi_irq_thread,
.baud_rate_div_min = STM32FX_SPI_BR_DIV_MIN,
.baud_rate_div_max = STM32FX_SPI_BR_DIV_MAX,
.has_fifo = false,
.has_device_mode = false,
.flags = SPI_CONTROLLER_MUST_TX,
};
static const struct stm32_spi_cfg stm32f7_spi_cfg = {
.regs = &stm32fx_spi_regspec,
.get_bpw_mask = stm32f7_spi_get_bpw_mask,
.disable = stm32fx_spi_disable,
.config = stm32fx_spi_config,
.set_bpw = stm32f7_spi_set_bpw,
.set_mode = stm32fx_spi_set_mode,
.write_tx = stm32f7_spi_write_tx,
.read_rx = stm32f7_spi_read_rx,
.transfer_one_dma_start = stm32f7_spi_transfer_one_dma_start,
.dma_tx_cb = stm32fx_spi_dma_tx_cb,
.dma_rx_cb = stm32_spi_dma_rx_cb,
.transfer_one_irq = stm32fx_spi_transfer_one_irq,
.irq_handler_event = stm32fx_spi_irq_event,
.irq_handler_thread = stm32fx_spi_irq_thread,
.baud_rate_div_min = STM32FX_SPI_BR_DIV_MIN,
.baud_rate_div_max = STM32FX_SPI_BR_DIV_MAX,
.has_fifo = false,
.flags = SPI_CONTROLLER_MUST_TX,
};
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,
.write_tx = stm32h7_spi_write_txfifo,
.read_rx = stm32h7_spi_read_rxfifo,
.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
.dma_rx_cb = stm32_spi_dma_rx_cb,
/*
* dma_tx_cb is not necessary since in case of TX, dma is followed by
* SPI access hence handling is performed within the SPI interrupt
*/
.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,
.has_device_mode = true,
};
/*
* STM32MP2 is compatible with the STM32H7 except:
* - enforce the DMA maxburst value to 1
* - spi8 have limited feature set (TSIZE_MAX = 1024, BPW of 8 OR 16)
*/
static const struct stm32_spi_cfg stm32mp25_spi_cfg = {
.regs = &stm32mp25_spi_regspec,
.get_fifo_size = stm32h7_spi_get_fifo_size,
.get_bpw_mask = stm32mp25_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 = stm32_spi_dma_rx_cb,
/*
* dma_tx_cb is not necessary since in case of TX, dma is followed by
* SPI access hence handling is performed within the SPI interrupt
*/
.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,
.prevent_dma_burst = true,
};
static const struct of_device_id stm32_spi_of_match[] = {
{ .compatible = "st,stm32mp25-spi", .data = (void *)&stm32mp25_spi_cfg },
{ .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg },
{ .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg },
{ .compatible = "st,stm32f7-spi", .data = (void *)&stm32f7_spi_cfg },
{},
};
MODULE_DEVICE_TABLE(of, stm32_spi_of_match);
static int stm32h7_spi_device_abort(struct spi_controller *ctrl)
{
spi_finalize_current_transfer(ctrl);
return 0;
}
static int stm32_spi_probe(struct platform_device *pdev)
{
struct spi_controller *ctrl;
struct stm32_spi *spi;
struct resource *res;
struct reset_control *rst;
struct device_node *np = pdev->dev.of_node;
bool device_mode;
int ret;
const struct stm32_spi_cfg *cfg = of_device_get_match_data(&pdev->dev);
device_mode = of_property_read_bool(np, "spi-slave");
if (!cfg->has_device_mode && device_mode) {
dev_err(&pdev->dev, "spi-slave not supported\n");
return -EPERM;
}
if (device_mode)
ctrl = devm_spi_alloc_target(&pdev->dev, sizeof(struct stm32_spi));
else
ctrl = devm_spi_alloc_host(&pdev->dev, sizeof(struct stm32_spi));
if (!ctrl) {
dev_err(&pdev->dev, "spi controller allocation failed\n");
return -ENOMEM;
}
platform_set_drvdata(pdev, ctrl);
spi = spi_controller_get_devdata(ctrl);
spi->dev = &pdev->dev;
spi->ctrl = ctrl;
spi->device_mode = device_mode;
spin_lock_init(&spi->lock);
spi->cfg = cfg;
spi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(spi->base))
return PTR_ERR(spi->base);
spi->phys_addr = (dma_addr_t)res->start;
spi->irq = platform_get_irq(pdev, 0);
if (spi->irq <= 0)
return spi->irq;
ret = devm_request_threaded_irq(&pdev->dev, spi->irq,
spi->cfg->irq_handler_event,
spi->cfg->irq_handler_thread,
IRQF_ONESHOT, pdev->name, ctrl);
if (ret) {
dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq,
ret);
return ret;
}
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);
return ret;
}
ret = clk_prepare_enable(spi->clk);
if (ret) {
dev_err(&pdev->dev, "clk enable failed: %d\n", ret);
return ret;
}
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;
}
rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
if (rst) {
if (IS_ERR(rst)) {
ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
"failed to get reset\n");
goto err_clk_disable;
}
reset_control_assert(rst);
udelay(2);
reset_control_deassert(rst);
}
if (spi->cfg->has_fifo)
spi->fifo_size = spi->cfg->get_fifo_size(spi);
spi->feature_set = STM32_SPI_FEATURE_FULL;
if (spi->cfg->regs->fullcfg.reg) {
spi->feature_set =
FIELD_GET(STM32MP25_SPI_HWCFGR1_FULLCFG,
readl_relaxed(spi->base + spi->cfg->regs->fullcfg.reg));
dev_dbg(spi->dev, "%s feature set\n",
spi->feature_set == STM32_SPI_FEATURE_FULL ? "full" : "limited");
}
/* Only for STM32H7 and after */
spi->t_size_max = spi->feature_set == STM32_SPI_FEATURE_FULL ?
STM32H7_SPI_TSIZE_MAX :
STM32MP25_SPI_TSIZE_MAX_LIMITED;
dev_dbg(spi->dev, "one message max size %d\n", spi->t_size_max);
ret = spi->cfg->config(spi);
if (ret) {
dev_err(&pdev->dev, "controller configuration failed: %d\n",
ret);
goto err_clk_disable;
}
ctrl->dev.of_node = pdev->dev.of_node;
ctrl->auto_runtime_pm = true;
ctrl->bus_num = pdev->id;
ctrl->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
SPI_3WIRE;
ctrl->bits_per_word_mask = spi->cfg->get_bpw_mask(spi);
ctrl->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min;
ctrl->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max;
ctrl->use_gpio_descriptors = true;
ctrl->optimize_message = stm32_spi_optimize_message;
ctrl->prepare_message = stm32_spi_prepare_msg;
ctrl->transfer_one = stm32_spi_transfer_one;
ctrl->unprepare_message = stm32_spi_unprepare_msg;
ctrl->flags = spi->cfg->flags;
if (STM32_SPI_DEVICE_MODE(spi))
ctrl->target_abort = stm32h7_spi_device_abort;
spi->dma_tx = dma_request_chan(spi->dev, "tx");
if (IS_ERR(spi->dma_tx)) {
ret = PTR_ERR(spi->dma_tx);
spi->dma_tx = NULL;
if (ret == -EPROBE_DEFER)
goto err_clk_disable;
dev_warn(&pdev->dev, "failed to request tx dma channel\n");
} else {
ctrl->dma_tx = spi->dma_tx;
}
spi->dma_rx = dma_request_chan(spi->dev, "rx");
if (IS_ERR(spi->dma_rx)) {
ret = PTR_ERR(spi->dma_rx);
spi->dma_rx = NULL;
if (ret == -EPROBE_DEFER)
goto err_dma_release;
dev_warn(&pdev->dev, "failed to request rx dma channel\n");
} else {
ctrl->dma_rx = spi->dma_rx;
}
if (spi->dma_tx || spi->dma_rx)
ctrl->can_dma = stm32_spi_can_dma;
pm_runtime_set_autosuspend_delay(&pdev->dev,
STM32_SPI_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_enable(&pdev->dev);
ret = spi_register_controller(ctrl);
if (ret) {
dev_err(&pdev->dev, "spi controller registration failed: %d\n",
ret);
goto err_pm_disable;
}
pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
dev_info(&pdev->dev, "driver initialized (%s mode)\n",
STM32_SPI_HOST_MODE(spi) ? "host" : "device");
return 0;
err_pm_disable:
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_dont_use_autosuspend(&pdev->dev);
err_dma_release:
if (spi->dma_tx)
dma_release_channel(spi->dma_tx);
if (spi->dma_rx)
dma_release_channel(spi->dma_rx);
err_clk_disable:
clk_disable_unprepare(spi->clk);
return ret;
}
static void stm32_spi_remove(struct platform_device *pdev)
{
struct spi_controller *ctrl = platform_get_drvdata(pdev);
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
pm_runtime_get_sync(&pdev->dev);
spi_unregister_controller(ctrl);
spi->cfg->disable(spi);
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_dont_use_autosuspend(&pdev->dev);
if (ctrl->dma_tx)
dma_release_channel(ctrl->dma_tx);
if (ctrl->dma_rx)
dma_release_channel(ctrl->dma_rx);
clk_disable_unprepare(spi->clk);
pinctrl_pm_select_sleep_state(&pdev->dev);
}
static int __maybe_unused stm32_spi_runtime_suspend(struct device *dev)
{
struct spi_controller *ctrl = dev_get_drvdata(dev);
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
clk_disable_unprepare(spi->clk);
return pinctrl_pm_select_sleep_state(dev);
}
static int __maybe_unused stm32_spi_runtime_resume(struct device *dev)
{
struct spi_controller *ctrl = dev_get_drvdata(dev);
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
int ret;
ret = pinctrl_pm_select_default_state(dev);
if (ret)
return ret;
return clk_prepare_enable(spi->clk);
}
static int __maybe_unused stm32_spi_suspend(struct device *dev)
{
struct spi_controller *ctrl = dev_get_drvdata(dev);
int ret;
ret = spi_controller_suspend(ctrl);
if (ret)
return ret;
return pm_runtime_force_suspend(dev);
}
static int __maybe_unused stm32_spi_resume(struct device *dev)
{
struct spi_controller *ctrl = dev_get_drvdata(dev);
struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
int ret;
ret = pm_runtime_force_resume(dev);
if (ret)
return ret;
ret = spi_controller_resume(ctrl);
if (ret) {
clk_disable_unprepare(spi->clk);
return ret;
}
ret = pm_runtime_resume_and_get(dev);
if (ret < 0) {
dev_err(dev, "Unable to power device:%d\n", ret);
return ret;
}
spi->cfg->config(spi);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
return 0;
}
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_new = 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");
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