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linux-next/drivers/spi/spi-pl022.c
Arvind Yadav 5b8d5ad230 spi: pl022: constify amba_id 
amba_id are not supposed to change at runtime. All functions
working with const amba_id. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-08-23 17:12:05 +01:00

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/*
* A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
*
* Copyright (C) 2008-2012 ST-Ericsson AB
* Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*
* Initial version inspired by:
* linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
* Initial adoption to PL022 by:
* Sachin Verma <sachin.verma@st.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/spi/spi.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/pl022.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/pm_runtime.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
/*
* This macro is used to define some register default values.
* reg is masked with mask, the OR:ed with an (again masked)
* val shifted sb steps to the left.
*/
#define SSP_WRITE_BITS(reg, val, mask, sb) \
((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
/*
* This macro is also used to define some default values.
* It will just shift val by sb steps to the left and mask
* the result with mask.
*/
#define GEN_MASK_BITS(val, mask, sb) \
(((val)<<(sb)) & (mask))
#define DRIVE_TX 0
#define DO_NOT_DRIVE_TX 1
#define DO_NOT_QUEUE_DMA 0
#define QUEUE_DMA 1
#define RX_TRANSFER 1
#define TX_TRANSFER 2
/*
* Macros to access SSP Registers with their offsets
*/
#define SSP_CR0(r) (r + 0x000)
#define SSP_CR1(r) (r + 0x004)
#define SSP_DR(r) (r + 0x008)
#define SSP_SR(r) (r + 0x00C)
#define SSP_CPSR(r) (r + 0x010)
#define SSP_IMSC(r) (r + 0x014)
#define SSP_RIS(r) (r + 0x018)
#define SSP_MIS(r) (r + 0x01C)
#define SSP_ICR(r) (r + 0x020)
#define SSP_DMACR(r) (r + 0x024)
#define SSP_CSR(r) (r + 0x030) /* vendor extension */
#define SSP_ITCR(r) (r + 0x080)
#define SSP_ITIP(r) (r + 0x084)
#define SSP_ITOP(r) (r + 0x088)
#define SSP_TDR(r) (r + 0x08C)
#define SSP_PID0(r) (r + 0xFE0)
#define SSP_PID1(r) (r + 0xFE4)
#define SSP_PID2(r) (r + 0xFE8)
#define SSP_PID3(r) (r + 0xFEC)
#define SSP_CID0(r) (r + 0xFF0)
#define SSP_CID1(r) (r + 0xFF4)
#define SSP_CID2(r) (r + 0xFF8)
#define SSP_CID3(r) (r + 0xFFC)
/*
* SSP Control Register 0 - SSP_CR0
*/
#define SSP_CR0_MASK_DSS (0x0FUL << 0)
#define SSP_CR0_MASK_FRF (0x3UL << 4)
#define SSP_CR0_MASK_SPO (0x1UL << 6)
#define SSP_CR0_MASK_SPH (0x1UL << 7)
#define SSP_CR0_MASK_SCR (0xFFUL << 8)
/*
* The ST version of this block moves som bits
* in SSP_CR0 and extends it to 32 bits
*/
#define SSP_CR0_MASK_DSS_ST (0x1FUL << 0)
#define SSP_CR0_MASK_HALFDUP_ST (0x1UL << 5)
#define SSP_CR0_MASK_CSS_ST (0x1FUL << 16)
#define SSP_CR0_MASK_FRF_ST (0x3UL << 21)
/*
* SSP Control Register 0 - SSP_CR1
*/
#define SSP_CR1_MASK_LBM (0x1UL << 0)
#define SSP_CR1_MASK_SSE (0x1UL << 1)
#define SSP_CR1_MASK_MS (0x1UL << 2)
#define SSP_CR1_MASK_SOD (0x1UL << 3)
/*
* The ST version of this block adds some bits
* in SSP_CR1
*/
#define SSP_CR1_MASK_RENDN_ST (0x1UL << 4)
#define SSP_CR1_MASK_TENDN_ST (0x1UL << 5)
#define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6)
#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
/* This one is only in the PL023 variant */
#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
/*
* SSP Status Register - SSP_SR
*/
#define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */
#define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */
#define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */
#define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */
#define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */
/*
* SSP Clock Prescale Register - SSP_CPSR
*/
#define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0)
/*
* SSP Interrupt Mask Set/Clear Register - SSP_IMSC
*/
#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
#define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */
#define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */
#define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */
/*
* SSP Raw Interrupt Status Register - SSP_RIS
*/
/* Receive Overrun Raw Interrupt status */
#define SSP_RIS_MASK_RORRIS (0x1UL << 0)
/* Receive Timeout Raw Interrupt status */
#define SSP_RIS_MASK_RTRIS (0x1UL << 1)
/* Receive FIFO Raw Interrupt status */
#define SSP_RIS_MASK_RXRIS (0x1UL << 2)
/* Transmit FIFO Raw Interrupt status */
#define SSP_RIS_MASK_TXRIS (0x1UL << 3)
/*
* SSP Masked Interrupt Status Register - SSP_MIS
*/
/* Receive Overrun Masked Interrupt status */
#define SSP_MIS_MASK_RORMIS (0x1UL << 0)
/* Receive Timeout Masked Interrupt status */
#define SSP_MIS_MASK_RTMIS (0x1UL << 1)
/* Receive FIFO Masked Interrupt status */
#define SSP_MIS_MASK_RXMIS (0x1UL << 2)
/* Transmit FIFO Masked Interrupt status */
#define SSP_MIS_MASK_TXMIS (0x1UL << 3)
/*
* SSP Interrupt Clear Register - SSP_ICR
*/
/* Receive Overrun Raw Clear Interrupt bit */
#define SSP_ICR_MASK_RORIC (0x1UL << 0)
/* Receive Timeout Clear Interrupt bit */
#define SSP_ICR_MASK_RTIC (0x1UL << 1)
/*
* SSP DMA Control Register - SSP_DMACR
*/
/* Receive DMA Enable bit */
#define SSP_DMACR_MASK_RXDMAE (0x1UL << 0)
/* Transmit DMA Enable bit */
#define SSP_DMACR_MASK_TXDMAE (0x1UL << 1)
/*
* SSP Chip Select Control Register - SSP_CSR
* (vendor extension)
*/
#define SSP_CSR_CSVALUE_MASK (0x1FUL << 0)
/*
* SSP Integration Test control Register - SSP_ITCR
*/
#define SSP_ITCR_MASK_ITEN (0x1UL << 0)
#define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1)
/*
* SSP Integration Test Input Register - SSP_ITIP
*/
#define ITIP_MASK_SSPRXD (0x1UL << 0)
#define ITIP_MASK_SSPFSSIN (0x1UL << 1)
#define ITIP_MASK_SSPCLKIN (0x1UL << 2)
#define ITIP_MASK_RXDMAC (0x1UL << 3)
#define ITIP_MASK_TXDMAC (0x1UL << 4)
#define ITIP_MASK_SSPTXDIN (0x1UL << 5)
/*
* SSP Integration Test output Register - SSP_ITOP
*/
#define ITOP_MASK_SSPTXD (0x1UL << 0)
#define ITOP_MASK_SSPFSSOUT (0x1UL << 1)
#define ITOP_MASK_SSPCLKOUT (0x1UL << 2)
#define ITOP_MASK_SSPOEn (0x1UL << 3)
#define ITOP_MASK_SSPCTLOEn (0x1UL << 4)
#define ITOP_MASK_RORINTR (0x1UL << 5)
#define ITOP_MASK_RTINTR (0x1UL << 6)
#define ITOP_MASK_RXINTR (0x1UL << 7)
#define ITOP_MASK_TXINTR (0x1UL << 8)
#define ITOP_MASK_INTR (0x1UL << 9)
#define ITOP_MASK_RXDMABREQ (0x1UL << 10)
#define ITOP_MASK_RXDMASREQ (0x1UL << 11)
#define ITOP_MASK_TXDMABREQ (0x1UL << 12)
#define ITOP_MASK_TXDMASREQ (0x1UL << 13)
/*
* SSP Test Data Register - SSP_TDR
*/
#define TDR_MASK_TESTDATA (0xFFFFFFFF)
/*
* Message State
* we use the spi_message.state (void *) pointer to
* hold a single state value, that's why all this
* (void *) casting is done here.
*/
#define STATE_START ((void *) 0)
#define STATE_RUNNING ((void *) 1)
#define STATE_DONE ((void *) 2)
#define STATE_ERROR ((void *) -1)
/*
* SSP State - Whether Enabled or Disabled
*/
#define SSP_DISABLED (0)
#define SSP_ENABLED (1)
/*
* SSP DMA State - Whether DMA Enabled or Disabled
*/
#define SSP_DMA_DISABLED (0)
#define SSP_DMA_ENABLED (1)
/*
* SSP Clock Defaults
*/
#define SSP_DEFAULT_CLKRATE 0x2
#define SSP_DEFAULT_PRESCALE 0x40
/*
* SSP Clock Parameter ranges
*/
#define CPSDVR_MIN 0x02
#define CPSDVR_MAX 0xFE
#define SCR_MIN 0x00
#define SCR_MAX 0xFF
/*
* SSP Interrupt related Macros
*/
#define DEFAULT_SSP_REG_IMSC 0x0UL
#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
#define ENABLE_ALL_INTERRUPTS ( \
SSP_IMSC_MASK_RORIM | \
SSP_IMSC_MASK_RTIM | \
SSP_IMSC_MASK_RXIM | \
SSP_IMSC_MASK_TXIM \
)
#define CLEAR_ALL_INTERRUPTS 0x3
#define SPI_POLLING_TIMEOUT 1000
/*
* The type of reading going on on this chip
*/
enum ssp_reading {
READING_NULL,
READING_U8,
READING_U16,
READING_U32
};
/**
* The type of writing going on on this chip
*/
enum ssp_writing {
WRITING_NULL,
WRITING_U8,
WRITING_U16,
WRITING_U32
};
/**
* struct vendor_data - vendor-specific config parameters
* for PL022 derivates
* @fifodepth: depth of FIFOs (both)
* @max_bpw: maximum number of bits per word
* @unidir: supports unidirection transfers
* @extended_cr: 32 bit wide control register 0 with extra
* features and extra features in CR1 as found in the ST variants
* @pl023: supports a subset of the ST extensions called "PL023"
* @internal_cs_ctrl: supports chip select control register
*/
struct vendor_data {
int fifodepth;
int max_bpw;
bool unidir;
bool extended_cr;
bool pl023;
bool loopback;
bool internal_cs_ctrl;
};
/**
* struct pl022 - This is the private SSP driver data structure
* @adev: AMBA device model hookup
* @vendor: vendor data for the IP block
* @phybase: the physical memory where the SSP device resides
* @virtbase: the virtual memory where the SSP is mapped
* @clk: outgoing clock "SPICLK" for the SPI bus
* @master: SPI framework hookup
* @master_info: controller-specific data from machine setup
* @pump_transfers: Tasklet used in Interrupt Transfer mode
* @cur_msg: Pointer to current spi_message being processed
* @cur_transfer: Pointer to current spi_transfer
* @cur_chip: pointer to current clients chip(assigned from controller_state)
* @next_msg_cs_active: the next message in the queue has been examined
* and it was found that it uses the same chip select as the previous
* message, so we left it active after the previous transfer, and it's
* active already.
* @tx: current position in TX buffer to be read
* @tx_end: end position in TX buffer to be read
* @rx: current position in RX buffer to be written
* @rx_end: end position in RX buffer to be written
* @read: the type of read currently going on
* @write: the type of write currently going on
* @exp_fifo_level: expected FIFO level
* @dma_rx_channel: optional channel for RX DMA
* @dma_tx_channel: optional channel for TX DMA
* @sgt_rx: scattertable for the RX transfer
* @sgt_tx: scattertable for the TX transfer
* @dummypage: a dummy page used for driving data on the bus with DMA
* @cur_cs: current chip select (gpio)
* @chipselects: list of chipselects (gpios)
*/
struct pl022 {
struct amba_device *adev;
struct vendor_data *vendor;
resource_size_t phybase;
void __iomem *virtbase;
struct clk *clk;
struct spi_master *master;
struct pl022_ssp_controller *master_info;
/* Message per-transfer pump */
struct tasklet_struct pump_transfers;
struct spi_message *cur_msg;
struct spi_transfer *cur_transfer;
struct chip_data *cur_chip;
bool next_msg_cs_active;
void *tx;
void *tx_end;
void *rx;
void *rx_end;
enum ssp_reading read;
enum ssp_writing write;
u32 exp_fifo_level;
enum ssp_rx_level_trig rx_lev_trig;
enum ssp_tx_level_trig tx_lev_trig;
/* DMA settings */
#ifdef CONFIG_DMA_ENGINE
struct dma_chan *dma_rx_channel;
struct dma_chan *dma_tx_channel;
struct sg_table sgt_rx;
struct sg_table sgt_tx;
char *dummypage;
bool dma_running;
#endif
int cur_cs;
int *chipselects;
};
/**
* struct chip_data - To maintain runtime state of SSP for each client chip
* @cr0: Value of control register CR0 of SSP - on later ST variants this
* register is 32 bits wide rather than just 16
* @cr1: Value of control register CR1 of SSP
* @dmacr: Value of DMA control Register of SSP
* @cpsr: Value of Clock prescale register
* @n_bytes: how many bytes(power of 2) reqd for a given data width of client
* @enable_dma: Whether to enable DMA or not
* @read: function ptr to be used to read when doing xfer for this chip
* @write: function ptr to be used to write when doing xfer for this chip
* @cs_control: chip select callback provided by chip
* @xfer_type: polling/interrupt/DMA
*
* Runtime state of the SSP controller, maintained per chip,
* This would be set according to the current message that would be served
*/
struct chip_data {
u32 cr0;
u16 cr1;
u16 dmacr;
u16 cpsr;
u8 n_bytes;
bool enable_dma;
enum ssp_reading read;
enum ssp_writing write;
void (*cs_control) (u32 command);
int xfer_type;
};
/**
* null_cs_control - Dummy chip select function
* @command: select/delect the chip
*
* If no chip select function is provided by client this is used as dummy
* chip select
*/
static void null_cs_control(u32 command)
{
pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
}
/**
* internal_cs_control - Control chip select signals via SSP_CSR.
* @pl022: SSP driver private data structure
* @command: select/delect the chip
*
* Used on controller with internal chip select control via SSP_CSR register
* (vendor extension). Each of the 5 LSB in the register controls one chip
* select signal.
*/
static void internal_cs_control(struct pl022 *pl022, u32 command)
{
u32 tmp;
tmp = readw(SSP_CSR(pl022->virtbase));
if (command == SSP_CHIP_SELECT)
tmp &= ~BIT(pl022->cur_cs);
else
tmp |= BIT(pl022->cur_cs);
writew(tmp, SSP_CSR(pl022->virtbase));
}
static void pl022_cs_control(struct pl022 *pl022, u32 command)
{
if (pl022->vendor->internal_cs_ctrl)
internal_cs_control(pl022, command);
else if (gpio_is_valid(pl022->cur_cs))
gpio_set_value(pl022->cur_cs, command);
else
pl022->cur_chip->cs_control(command);
}
/**
* giveback - current spi_message is over, schedule next message and call
* callback of this message. Assumes that caller already
* set message->status; dma and pio irqs are blocked
* @pl022: SSP driver private data structure
*/
static void giveback(struct pl022 *pl022)
{
struct spi_transfer *last_transfer;
pl022->next_msg_cs_active = false;
last_transfer = list_last_entry(&pl022->cur_msg->transfers,
struct spi_transfer, transfer_list);
/* Delay if requested before any change in chip select */
if (last_transfer->delay_usecs)
/*
* FIXME: This runs in interrupt context.
* Is this really smart?
*/
udelay(last_transfer->delay_usecs);
if (!last_transfer->cs_change) {
struct spi_message *next_msg;
/*
* cs_change was not set. We can keep the chip select
* enabled if there is message in the queue and it is
* for the same spi device.
*
* We cannot postpone this until pump_messages, because
* after calling msg->complete (below) the driver that
* sent the current message could be unloaded, which
* could invalidate the cs_control() callback...
*/
/* get a pointer to the next message, if any */
next_msg = spi_get_next_queued_message(pl022->master);
/*
* see if the next and current messages point
* to the same spi device.
*/
if (next_msg && next_msg->spi != pl022->cur_msg->spi)
next_msg = NULL;
if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
else
pl022->next_msg_cs_active = true;
}
pl022->cur_msg = NULL;
pl022->cur_transfer = NULL;
pl022->cur_chip = NULL;
/* disable the SPI/SSP operation */
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
spi_finalize_current_message(pl022->master);
}
/**
* flush - flush the FIFO to reach a clean state
* @pl022: SSP driver private data structure
*/
static int flush(struct pl022 *pl022)
{
unsigned long limit = loops_per_jiffy << 1;
dev_dbg(&pl022->adev->dev, "flush\n");
do {
while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
readw(SSP_DR(pl022->virtbase));
} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
pl022->exp_fifo_level = 0;
return limit;
}
/**
* restore_state - Load configuration of current chip
* @pl022: SSP driver private data structure
*/
static void restore_state(struct pl022 *pl022)
{
struct chip_data *chip = pl022->cur_chip;
if (pl022->vendor->extended_cr)
writel(chip->cr0, SSP_CR0(pl022->virtbase));
else
writew(chip->cr0, SSP_CR0(pl022->virtbase));
writew(chip->cr1, SSP_CR1(pl022->virtbase));
writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}
/*
* Default SSP Register Values
*/
#define DEFAULT_SSP_REG_CR0 ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)
/* ST versions have slightly different bit layout */
#define DEFAULT_SSP_REG_CR0_ST ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16) | \
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
)
/* The PL023 version is slightly different again */
#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)
#define DEFAULT_SSP_REG_CR1 ( \
GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
)
/* ST versions extend this register to use all 16 bits */
#define DEFAULT_SSP_REG_CR1_ST ( \
DEFAULT_SSP_REG_CR1 | \
GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
)
/*
* The PL023 variant has further differences: no loopback mode, no microwire
* support, and a new clock feedback delay setting.
*/
#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
)
#define DEFAULT_SSP_REG_CPSR ( \
GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
)
#define DEFAULT_SSP_REG_DMACR (\
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
)
/**
* load_ssp_default_config - Load default configuration for SSP
* @pl022: SSP driver private data structure
*/
static void load_ssp_default_config(struct pl022 *pl022)
{
if (pl022->vendor->pl023) {
writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
} else if (pl022->vendor->extended_cr) {
writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
} else {
writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
}
writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}
/**
* This will write to TX and read from RX according to the parameters
* set in pl022.
*/
static void readwriter(struct pl022 *pl022)
{
/*
* The FIFO depth is different between primecell variants.
* I believe filling in too much in the FIFO might cause
* errons in 8bit wide transfers on ARM variants (just 8 words
* FIFO, means only 8x8 = 64 bits in FIFO) at least.
*
* To prevent this issue, the TX FIFO is only filled to the
* unused RX FIFO fill length, regardless of what the TX
* FIFO status flag indicates.
*/
dev_dbg(&pl022->adev->dev,
"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
/* Read as much as you can */
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
&& (pl022->rx < pl022->rx_end)) {
switch (pl022->read) {
case READING_NULL:
readw(SSP_DR(pl022->virtbase));
break;
case READING_U8:
*(u8 *) (pl022->rx) =
readw(SSP_DR(pl022->virtbase)) & 0xFFU;
break;
case READING_U16:
*(u16 *) (pl022->rx) =
(u16) readw(SSP_DR(pl022->virtbase));
break;
case READING_U32:
*(u32 *) (pl022->rx) =
readl(SSP_DR(pl022->virtbase));
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
pl022->exp_fifo_level--;
}
/*
* Write as much as possible up to the RX FIFO size
*/
while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
&& (pl022->tx < pl022->tx_end)) {
switch (pl022->write) {
case WRITING_NULL:
writew(0x0, SSP_DR(pl022->virtbase));
break;
case WRITING_U8:
writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
break;
case WRITING_U16:
writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
break;
case WRITING_U32:
writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
break;
}
pl022->tx += (pl022->cur_chip->n_bytes);
pl022->exp_fifo_level++;
/*
* This inner reader takes care of things appearing in the RX
* FIFO as we're transmitting. This will happen a lot since the
* clock starts running when you put things into the TX FIFO,
* and then things are continuously clocked into the RX FIFO.
*/
while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
&& (pl022->rx < pl022->rx_end)) {
switch (pl022->read) {
case READING_NULL:
readw(SSP_DR(pl022->virtbase));
break;
case READING_U8:
*(u8 *) (pl022->rx) =
readw(SSP_DR(pl022->virtbase)) & 0xFFU;
break;
case READING_U16:
*(u16 *) (pl022->rx) =
(u16) readw(SSP_DR(pl022->virtbase));
break;
case READING_U32:
*(u32 *) (pl022->rx) =
readl(SSP_DR(pl022->virtbase));
break;
}
pl022->rx += (pl022->cur_chip->n_bytes);
pl022->exp_fifo_level--;
}
}
/*
* When we exit here the TX FIFO should be full and the RX FIFO
* should be empty
*/
}
/**
* next_transfer - Move to the Next transfer in the current spi message
* @pl022: SSP driver private data structure
*
* This function moves though the linked list of spi transfers in the
* current spi message and returns with the state of current spi
* message i.e whether its last transfer is done(STATE_DONE) or
* Next transfer is ready(STATE_RUNNING)
*/
static void *next_transfer(struct pl022 *pl022)
{
struct spi_message *msg = pl022->cur_msg;
struct spi_transfer *trans = pl022->cur_transfer;
/* Move to next transfer */
if (trans->transfer_list.next != &msg->transfers) {
pl022->cur_transfer =
list_entry(trans->transfer_list.next,
struct spi_transfer, transfer_list);
return STATE_RUNNING;
}
return STATE_DONE;
}
/*
* This DMA functionality is only compiled in if we have
* access to the generic DMA devices/DMA engine.
*/
#ifdef CONFIG_DMA_ENGINE
static void unmap_free_dma_scatter(struct pl022 *pl022)
{
/* Unmap and free the SG tables */
dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
sg_free_table(&pl022->sgt_rx);
sg_free_table(&pl022->sgt_tx);
}
static void dma_callback(void *data)
{
struct pl022 *pl022 = data;
struct spi_message *msg = pl022->cur_msg;
BUG_ON(!pl022->sgt_rx.sgl);
#ifdef VERBOSE_DEBUG
/*
* Optionally dump out buffers to inspect contents, this is
* good if you want to convince yourself that the loopback
* read/write contents are the same, when adopting to a new
* DMA engine.
*/
{
struct scatterlist *sg;
unsigned int i;
dma_sync_sg_for_cpu(&pl022->adev->dev,
pl022->sgt_rx.sgl,
pl022->sgt_rx.nents,
DMA_FROM_DEVICE);
for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
print_hex_dump(KERN_ERR, "SPI RX: ",
DUMP_PREFIX_OFFSET,
16,
1,
sg_virt(sg),
sg_dma_len(sg),
1);
}
for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
print_hex_dump(KERN_ERR, "SPI TX: ",
DUMP_PREFIX_OFFSET,
16,
1,
sg_virt(sg),
sg_dma_len(sg),
1);
}
}
#endif
unmap_free_dma_scatter(pl022);
/* Update total bytes transferred */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
}
static void setup_dma_scatter(struct pl022 *pl022,
void *buffer,
unsigned int length,
struct sg_table *sgtab)
{
struct scatterlist *sg;
int bytesleft = length;
void *bufp = buffer;
int mapbytes;
int i;
if (buffer) {
for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
/*
* If there are less bytes left than what fits
* in the current page (plus page alignment offset)
* we just feed in this, else we stuff in as much
* as we can.
*/
if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
mapbytes = bytesleft;
else
mapbytes = PAGE_SIZE - offset_in_page(bufp);
sg_set_page(sg, virt_to_page(bufp),
mapbytes, offset_in_page(bufp));
bufp += mapbytes;
bytesleft -= mapbytes;
dev_dbg(&pl022->adev->dev,
"set RX/TX target page @ %p, %d bytes, %d left\n",
bufp, mapbytes, bytesleft);
}
} else {
/* Map the dummy buffer on every page */
for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
if (bytesleft < PAGE_SIZE)
mapbytes = bytesleft;
else
mapbytes = PAGE_SIZE;
sg_set_page(sg, virt_to_page(pl022->dummypage),
mapbytes, 0);
bytesleft -= mapbytes;
dev_dbg(&pl022->adev->dev,
"set RX/TX to dummy page %d bytes, %d left\n",
mapbytes, bytesleft);
}
}
BUG_ON(bytesleft);
}
/**
* configure_dma - configures the channels for the next transfer
* @pl022: SSP driver's private data structure
*/
static int configure_dma(struct pl022 *pl022)
{
struct dma_slave_config rx_conf = {
.src_addr = SSP_DR(pl022->phybase),
.direction = DMA_DEV_TO_MEM,
.device_fc = false,
};
struct dma_slave_config tx_conf = {
.dst_addr = SSP_DR(pl022->phybase),
.direction = DMA_MEM_TO_DEV,
.device_fc = false,
};
unsigned int pages;
int ret;
int rx_sglen, tx_sglen;
struct dma_chan *rxchan = pl022->dma_rx_channel;
struct dma_chan *txchan = pl022->dma_tx_channel;
struct dma_async_tx_descriptor *rxdesc;
struct dma_async_tx_descriptor *txdesc;
/* Check that the channels are available */
if (!rxchan || !txchan)
return -ENODEV;
/*
* If supplied, the DMA burstsize should equal the FIFO trigger level.
* Notice that the DMA engine uses one-to-one mapping. Since we can
* not trigger on 2 elements this needs explicit mapping rather than
* calculation.
*/
switch (pl022->rx_lev_trig) {
case SSP_RX_1_OR_MORE_ELEM:
rx_conf.src_maxburst = 1;
break;
case SSP_RX_4_OR_MORE_ELEM:
rx_conf.src_maxburst = 4;
break;
case SSP_RX_8_OR_MORE_ELEM:
rx_conf.src_maxburst = 8;
break;
case SSP_RX_16_OR_MORE_ELEM:
rx_conf.src_maxburst = 16;
break;
case SSP_RX_32_OR_MORE_ELEM:
rx_conf.src_maxburst = 32;
break;
default:
rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
break;
}
switch (pl022->tx_lev_trig) {
case SSP_TX_1_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 1;
break;
case SSP_TX_4_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 4;
break;
case SSP_TX_8_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 8;
break;
case SSP_TX_16_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 16;
break;
case SSP_TX_32_OR_MORE_EMPTY_LOC:
tx_conf.dst_maxburst = 32;
break;
default:
tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
break;
}
switch (pl022->read) {
case READING_NULL:
/* Use the same as for writing */
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
break;
case READING_U8:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case READING_U16:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case READING_U32:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
}
switch (pl022->write) {
case WRITING_NULL:
/* Use the same as for reading */
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
break;
case WRITING_U8:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case WRITING_U16:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case WRITING_U32:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
}
/* SPI pecularity: we need to read and write the same width */
if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
rx_conf.src_addr_width = tx_conf.dst_addr_width;
if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
tx_conf.dst_addr_width = rx_conf.src_addr_width;
BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
dmaengine_slave_config(rxchan, &rx_conf);
dmaengine_slave_config(txchan, &tx_conf);
/* Create sglists for the transfers */
pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
if (ret)
goto err_alloc_rx_sg;
ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
if (ret)
goto err_alloc_tx_sg;
/* Fill in the scatterlists for the RX+TX buffers */
setup_dma_scatter(pl022, pl022->rx,
pl022->cur_transfer->len, &pl022->sgt_rx);
setup_dma_scatter(pl022, pl022->tx,
pl022->cur_transfer->len, &pl022->sgt_tx);
/* Map DMA buffers */
rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
if (!rx_sglen)
goto err_rx_sgmap;
tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
if (!tx_sglen)
goto err_tx_sgmap;
/* Send both scatterlists */
rxdesc = dmaengine_prep_slave_sg(rxchan,
pl022->sgt_rx.sgl,
rx_sglen,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!rxdesc)
goto err_rxdesc;
txdesc = dmaengine_prep_slave_sg(txchan,
pl022->sgt_tx.sgl,
tx_sglen,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!txdesc)
goto err_txdesc;
/* Put the callback on the RX transfer only, that should finish last */
rxdesc->callback = dma_callback;
rxdesc->callback_param = pl022;
/* Submit and fire RX and TX with TX last so we're ready to read! */
dmaengine_submit(rxdesc);
dmaengine_submit(txdesc);
dma_async_issue_pending(rxchan);
dma_async_issue_pending(txchan);
pl022->dma_running = true;
return 0;
err_txdesc:
dmaengine_terminate_all(txchan);
err_rxdesc:
dmaengine_terminate_all(rxchan);
dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
err_tx_sgmap:
dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
err_rx_sgmap:
sg_free_table(&pl022->sgt_tx);
err_alloc_tx_sg:
sg_free_table(&pl022->sgt_rx);
err_alloc_rx_sg:
return -ENOMEM;
}
static int pl022_dma_probe(struct pl022 *pl022)
{
dma_cap_mask_t mask;
/* Try to acquire a generic DMA engine slave channel */
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
/*
* We need both RX and TX channels to do DMA, else do none
* of them.
*/
pl022->dma_rx_channel = dma_request_channel(mask,
pl022->master_info->dma_filter,
pl022->master_info->dma_rx_param);
if (!pl022->dma_rx_channel) {
dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
goto err_no_rxchan;
}
pl022->dma_tx_channel = dma_request_channel(mask,
pl022->master_info->dma_filter,
pl022->master_info->dma_tx_param);
if (!pl022->dma_tx_channel) {
dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
goto err_no_txchan;
}
pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pl022->dummypage)
goto err_no_dummypage;
dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
dma_chan_name(pl022->dma_rx_channel),
dma_chan_name(pl022->dma_tx_channel));
return 0;
err_no_dummypage:
dma_release_channel(pl022->dma_tx_channel);
err_no_txchan:
dma_release_channel(pl022->dma_rx_channel);
pl022->dma_rx_channel = NULL;
err_no_rxchan:
dev_err(&pl022->adev->dev,
"Failed to work in dma mode, work without dma!\n");
return -ENODEV;
}
static int pl022_dma_autoprobe(struct pl022 *pl022)
{
struct device *dev = &pl022->adev->dev;
struct dma_chan *chan;
int err;
/* automatically configure DMA channels from platform, normally using DT */
chan = dma_request_slave_channel_reason(dev, "rx");
if (IS_ERR(chan)) {
err = PTR_ERR(chan);
goto err_no_rxchan;
}
pl022->dma_rx_channel = chan;
chan = dma_request_slave_channel_reason(dev, "tx");
if (IS_ERR(chan)) {
err = PTR_ERR(chan);
goto err_no_txchan;
}
pl022->dma_tx_channel = chan;
pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pl022->dummypage) {
err = -ENOMEM;
goto err_no_dummypage;
}
return 0;
err_no_dummypage:
dma_release_channel(pl022->dma_tx_channel);
pl022->dma_tx_channel = NULL;
err_no_txchan:
dma_release_channel(pl022->dma_rx_channel);
pl022->dma_rx_channel = NULL;
err_no_rxchan:
return err;
}
static void terminate_dma(struct pl022 *pl022)
{
struct dma_chan *rxchan = pl022->dma_rx_channel;
struct dma_chan *txchan = pl022->dma_tx_channel;
dmaengine_terminate_all(rxchan);
dmaengine_terminate_all(txchan);
unmap_free_dma_scatter(pl022);
pl022->dma_running = false;
}
static void pl022_dma_remove(struct pl022 *pl022)
{
if (pl022->dma_running)
terminate_dma(pl022);
if (pl022->dma_tx_channel)
dma_release_channel(pl022->dma_tx_channel);
if (pl022->dma_rx_channel)
dma_release_channel(pl022->dma_rx_channel);
kfree(pl022->dummypage);
}
#else
static inline int configure_dma(struct pl022 *pl022)
{
return -ENODEV;
}
static inline int pl022_dma_autoprobe(struct pl022 *pl022)
{
return 0;
}
static inline int pl022_dma_probe(struct pl022 *pl022)
{
return 0;
}
static inline void pl022_dma_remove(struct pl022 *pl022)
{
}
#endif
/**
* pl022_interrupt_handler - Interrupt handler for SSP controller
*
* This function handles interrupts generated for an interrupt based transfer.
* If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
* current message's state as STATE_ERROR and schedule the tasklet
* pump_transfers which will do the postprocessing of the current message by
* calling giveback(). Otherwise it reads data from RX FIFO till there is no
* more data, and writes data in TX FIFO till it is not full. If we complete
* the transfer we move to the next transfer and schedule the tasklet.
*/
static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
{
struct pl022 *pl022 = dev_id;
struct spi_message *msg = pl022->cur_msg;
u16 irq_status = 0;
if (unlikely(!msg)) {
dev_err(&pl022->adev->dev,
"bad message state in interrupt handler");
/* Never fail */
return IRQ_HANDLED;
}
/* Read the Interrupt Status Register */
irq_status = readw(SSP_MIS(pl022->virtbase));
if (unlikely(!irq_status))
return IRQ_NONE;
/*
* This handles the FIFO interrupts, the timeout
* interrupts are flatly ignored, they cannot be
* trusted.
*/
if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
/*
* Overrun interrupt - bail out since our Data has been
* corrupted
*/
dev_err(&pl022->adev->dev, "FIFO overrun\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
dev_err(&pl022->adev->dev,
"RXFIFO is full\n");
/*
* Disable and clear interrupts, disable SSP,
* mark message with bad status so it can be
* retried.
*/
writew(DISABLE_ALL_INTERRUPTS,
SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
msg->state = STATE_ERROR;
/* Schedule message queue handler */
tasklet_schedule(&pl022->pump_transfers);
return IRQ_HANDLED;
}
readwriter(pl022);
if (pl022->tx == pl022->tx_end) {
/* Disable Transmit interrupt, enable receive interrupt */
writew((readw(SSP_IMSC(pl022->virtbase)) &
~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
SSP_IMSC(pl022->virtbase));
}
/*
* Since all transactions must write as much as shall be read,
* we can conclude the entire transaction once RX is complete.
* At this point, all TX will always be finished.
*/
if (pl022->rx >= pl022->rx_end) {
writew(DISABLE_ALL_INTERRUPTS,
SSP_IMSC(pl022->virtbase));
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
if (unlikely(pl022->rx > pl022->rx_end)) {
dev_warn(&pl022->adev->dev, "read %u surplus "
"bytes (did you request an odd "
"number of bytes on a 16bit bus?)\n",
(u32) (pl022->rx - pl022->rx_end));
}
/* Update total bytes transferred */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
return IRQ_HANDLED;
}
return IRQ_HANDLED;
}
/**
* This sets up the pointers to memory for the next message to
* send out on the SPI bus.
*/
static int set_up_next_transfer(struct pl022 *pl022,
struct spi_transfer *transfer)
{
int residue;
/* Sanity check the message for this bus width */
residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
if (unlikely(residue != 0)) {
dev_err(&pl022->adev->dev,
"message of %u bytes to transmit but the current "
"chip bus has a data width of %u bytes!\n",
pl022->cur_transfer->len,
pl022->cur_chip->n_bytes);
dev_err(&pl022->adev->dev, "skipping this message\n");
return -EIO;
}
pl022->tx = (void *)transfer->tx_buf;
pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
pl022->rx = (void *)transfer->rx_buf;
pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
pl022->write =
pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
return 0;
}
/**
* pump_transfers - Tasklet function which schedules next transfer
* when running in interrupt or DMA transfer mode.
* @data: SSP driver private data structure
*
*/
static void pump_transfers(unsigned long data)
{
struct pl022 *pl022 = (struct pl022 *) data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
/* Get current state information */
message = pl022->cur_msg;
transfer = pl022->cur_transfer;
/* Handle for abort */
if (message->state == STATE_ERROR) {
message->status = -EIO;
giveback(pl022);
return;
}
/* Handle end of message */
if (message->state == STATE_DONE) {
message->status = 0;
giveback(pl022);
return;
}
/* Delay if requested at end of transfer before CS change */
if (message->state == STATE_RUNNING) {
previous = list_entry(transfer->transfer_list.prev,
struct spi_transfer,
transfer_list);
if (previous->delay_usecs)
/*
* FIXME: This runs in interrupt context.
* Is this really smart?
*/
udelay(previous->delay_usecs);
/* Reselect chip select only if cs_change was requested */
if (previous->cs_change)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
}
if (set_up_next_transfer(pl022, transfer)) {
message->state = STATE_ERROR;
message->status = -EIO;
giveback(pl022);
return;
}
/* Flush the FIFOs and let's go! */
flush(pl022);
if (pl022->cur_chip->enable_dma) {
if (configure_dma(pl022)) {
dev_dbg(&pl022->adev->dev,
"configuration of DMA failed, fall back to interrupt mode\n");
goto err_config_dma;
}
return;
}
err_config_dma:
/* enable all interrupts except RX */
writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
}
static void do_interrupt_dma_transfer(struct pl022 *pl022)
{
/*
* Default is to enable all interrupts except RX -
* this will be enabled once TX is complete
*/
u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
/* Enable target chip, if not already active */
if (!pl022->next_msg_cs_active)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
/* Error path */
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
/* If we're using DMA, set up DMA here */
if (pl022->cur_chip->enable_dma) {
/* Configure DMA transfer */
if (configure_dma(pl022)) {
dev_dbg(&pl022->adev->dev,
"configuration of DMA failed, fall back to interrupt mode\n");
goto err_config_dma;
}
/* Disable interrupts in DMA mode, IRQ from DMA controller */
irqflags = DISABLE_ALL_INTERRUPTS;
}
err_config_dma:
/* Enable SSP, turn on interrupts */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
writew(irqflags, SSP_IMSC(pl022->virtbase));
}
static void do_polling_transfer(struct pl022 *pl022)
{
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct chip_data *chip;
unsigned long time, timeout;
chip = pl022->cur_chip;
message = pl022->cur_msg;
while (message->state != STATE_DONE) {
/* Handle for abort */
if (message->state == STATE_ERROR)
break;
transfer = pl022->cur_transfer;
/* Delay if requested at end of transfer */
if (message->state == STATE_RUNNING) {
previous =
list_entry(transfer->transfer_list.prev,
struct spi_transfer, transfer_list);
if (previous->delay_usecs)
udelay(previous->delay_usecs);
if (previous->cs_change)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
if (!pl022->next_msg_cs_active)
pl022_cs_control(pl022, SSP_CHIP_SELECT);
}
/* Configuration Changing Per Transfer */
if (set_up_next_transfer(pl022, transfer)) {
/* Error path */
message->state = STATE_ERROR;
break;
}
/* Flush FIFOs and enable SSP */
flush(pl022);
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
time = jiffies;
readwriter(pl022);
if (time_after(time, timeout)) {
dev_warn(&pl022->adev->dev,
"%s: timeout!\n", __func__);
message->state = STATE_ERROR;
goto out;
}
cpu_relax();
}
/* Update total byte transferred */
message->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
message->state = next_transfer(pl022);
}
out:
/* Handle end of message */
if (message->state == STATE_DONE)
message->status = 0;
else
message->status = -EIO;
giveback(pl022);
return;
}
static int pl022_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct pl022 *pl022 = spi_master_get_devdata(master);
/* Initial message state */
pl022->cur_msg = msg;
msg->state = STATE_START;
pl022->cur_transfer = list_entry(msg->transfers.next,
struct spi_transfer, transfer_list);
/* Setup the SPI using the per chip configuration */
pl022->cur_chip = spi_get_ctldata(msg->spi);
pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
restore_state(pl022);
flush(pl022);
if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
do_polling_transfer(pl022);
else
do_interrupt_dma_transfer(pl022);
return 0;
}
static int pl022_unprepare_transfer_hardware(struct spi_master *master)
{
struct pl022 *pl022 = spi_master_get_devdata(master);
/* nothing more to do - disable spi/ssp and power off */
writew((readw(SSP_CR1(pl022->virtbase)) &
(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
return 0;
}
static int verify_controller_parameters(struct pl022 *pl022,
struct pl022_config_chip const *chip_info)
{
if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
|| (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
dev_err(&pl022->adev->dev,
"interface is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
(!pl022->vendor->unidir)) {
dev_err(&pl022->adev->dev,
"unidirectional mode not supported in this "
"hardware version\n");
return -EINVAL;
}
if ((chip_info->hierarchy != SSP_MASTER)
&& (chip_info->hierarchy != SSP_SLAVE)) {
dev_err(&pl022->adev->dev,
"hierarchy is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->com_mode != INTERRUPT_TRANSFER)
&& (chip_info->com_mode != DMA_TRANSFER)
&& (chip_info->com_mode != POLLING_TRANSFER)) {
dev_err(&pl022->adev->dev,
"Communication mode is configured incorrectly\n");
return -EINVAL;
}
switch (chip_info->rx_lev_trig) {
case SSP_RX_1_OR_MORE_ELEM:
case SSP_RX_4_OR_MORE_ELEM:
case SSP_RX_8_OR_MORE_ELEM:
/* These are always OK, all variants can handle this */
break;
case SSP_RX_16_OR_MORE_ELEM:
if (pl022->vendor->fifodepth < 16) {
dev_err(&pl022->adev->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
case SSP_RX_32_OR_MORE_ELEM:
if (pl022->vendor->fifodepth < 32) {
dev_err(&pl022->adev->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
default:
dev_err(&pl022->adev->dev,
"RX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
switch (chip_info->tx_lev_trig) {
case SSP_TX_1_OR_MORE_EMPTY_LOC:
case SSP_TX_4_OR_MORE_EMPTY_LOC:
case SSP_TX_8_OR_MORE_EMPTY_LOC:
/* These are always OK, all variants can handle this */
break;
case SSP_TX_16_OR_MORE_EMPTY_LOC:
if (pl022->vendor->fifodepth < 16) {
dev_err(&pl022->adev->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
case SSP_TX_32_OR_MORE_EMPTY_LOC:
if (pl022->vendor->fifodepth < 32) {
dev_err(&pl022->adev->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
break;
default:
dev_err(&pl022->adev->dev,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
if ((chip_info->ctrl_len < SSP_BITS_4)
|| (chip_info->ctrl_len > SSP_BITS_32)) {
dev_err(&pl022->adev->dev,
"CTRL LEN is configured incorrectly\n");
return -EINVAL;
}
if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
&& (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
dev_err(&pl022->adev->dev,
"Wait State is configured incorrectly\n");
return -EINVAL;
}
/* Half duplex is only available in the ST Micro version */
if (pl022->vendor->extended_cr) {
if ((chip_info->duplex !=
SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
&& (chip_info->duplex !=
SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
dev_err(&pl022->adev->dev,
"Microwire duplex mode is configured incorrectly\n");
return -EINVAL;
}
} else {
if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
dev_err(&pl022->adev->dev,
"Microwire half duplex mode requested,"
" but this is only available in the"
" ST version of PL022\n");
return -EINVAL;
}
}
return 0;
}
static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
{
return rate / (cpsdvsr * (1 + scr));
}
static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
ssp_clock_params * clk_freq)
{
/* Lets calculate the frequency parameters */
u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
best_scr = 0, tmp, found = 0;
rate = clk_get_rate(pl022->clk);
/* cpsdvscr = 2 & scr 0 */
max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
/* cpsdvsr = 254 & scr = 255 */
min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
if (freq > max_tclk)
dev_warn(&pl022->adev->dev,
"Max speed that can be programmed is %d Hz, you requested %d\n",
max_tclk, freq);
if (freq < min_tclk) {
dev_err(&pl022->adev->dev,
"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
freq, min_tclk);
return -EINVAL;
}
/*
* best_freq will give closest possible available rate (<= requested
* freq) for all values of scr & cpsdvsr.
*/
while ((cpsdvsr <= CPSDVR_MAX) && !found) {
while (scr <= SCR_MAX) {
tmp = spi_rate(rate, cpsdvsr, scr);
if (tmp > freq) {
/* we need lower freq */
scr++;
continue;
}
/*
* If found exact value, mark found and break.
* If found more closer value, update and break.
*/
if (tmp > best_freq) {
best_freq = tmp;
best_cpsdvsr = cpsdvsr;
best_scr = scr;
if (tmp == freq)
found = 1;
}
/*
* increased scr will give lower rates, which are not
* required
*/
break;
}
cpsdvsr += 2;
scr = SCR_MIN;
}
WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
freq);
clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
clk_freq->scr = (u8) (best_scr & 0xFF);
dev_dbg(&pl022->adev->dev,
"SSP Target Frequency is: %u, Effective Frequency is %u\n",
freq, best_freq);
dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
clk_freq->cpsdvsr, clk_freq->scr);
return 0;
}
/*
* A piece of default chip info unless the platform
* supplies it.
*/
static const struct pl022_config_chip pl022_default_chip_info = {
.com_mode = POLLING_TRANSFER,
.iface = SSP_INTERFACE_MOTOROLA_SPI,
.hierarchy = SSP_SLAVE,
.slave_tx_disable = DO_NOT_DRIVE_TX,
.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
.ctrl_len = SSP_BITS_8,
.wait_state = SSP_MWIRE_WAIT_ZERO,
.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
.cs_control = null_cs_control,
};
/**
* pl022_setup - setup function registered to SPI master framework
* @spi: spi device which is requesting setup
*
* This function is registered to the SPI framework for this SPI master
* controller. If it is the first time when setup is called by this device,
* this function will initialize the runtime state for this chip and save
* the same in the device structure. Else it will update the runtime info
* with the updated chip info. Nothing is really being written to the
* controller hardware here, that is not done until the actual transfer
* commence.
*/
static int pl022_setup(struct spi_device *spi)
{
struct pl022_config_chip const *chip_info;
struct pl022_config_chip chip_info_dt;
struct chip_data *chip;
struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
int status = 0;
struct pl022 *pl022 = spi_master_get_devdata(spi->master);
unsigned int bits = spi->bits_per_word;
u32 tmp;
struct device_node *np = spi->dev.of_node;
if (!spi->max_speed_hz)
return -EINVAL;
/* Get controller_state if one is supplied */
chip = spi_get_ctldata(spi);
if (chip == NULL) {
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
if (!chip)
return -ENOMEM;
dev_dbg(&spi->dev,
"allocated memory for controller's runtime state\n");
}
/* Get controller data if one is supplied */
chip_info = spi->controller_data;
if (chip_info == NULL) {
if (np) {
chip_info_dt = pl022_default_chip_info;
chip_info_dt.hierarchy = SSP_MASTER;
of_property_read_u32(np, "pl022,interface",
&chip_info_dt.iface);
of_property_read_u32(np, "pl022,com-mode",
&chip_info_dt.com_mode);
of_property_read_u32(np, "pl022,rx-level-trig",
&chip_info_dt.rx_lev_trig);
of_property_read_u32(np, "pl022,tx-level-trig",
&chip_info_dt.tx_lev_trig);
of_property_read_u32(np, "pl022,ctrl-len",
&chip_info_dt.ctrl_len);
of_property_read_u32(np, "pl022,wait-state",
&chip_info_dt.wait_state);
of_property_read_u32(np, "pl022,duplex",
&chip_info_dt.duplex);
chip_info = &chip_info_dt;
} else {
chip_info = &pl022_default_chip_info;
/* spi_board_info.controller_data not is supplied */
dev_dbg(&spi->dev,
"using default controller_data settings\n");
}
} else
dev_dbg(&spi->dev,
"using user supplied controller_data settings\n");
/*
* We can override with custom divisors, else we use the board
* frequency setting
*/
if ((0 == chip_info->clk_freq.cpsdvsr)
&& (0 == chip_info->clk_freq.scr)) {
status = calculate_effective_freq(pl022,
spi->max_speed_hz,
&clk_freq);
if (status < 0)
goto err_config_params;
} else {
memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
if ((clk_freq.cpsdvsr % 2) != 0)
clk_freq.cpsdvsr =
clk_freq.cpsdvsr - 1;
}
if ((clk_freq.cpsdvsr < CPSDVR_MIN)
|| (clk_freq.cpsdvsr > CPSDVR_MAX)) {
status = -EINVAL;
dev_err(&spi->dev,
"cpsdvsr is configured incorrectly\n");
goto err_config_params;
}
status = verify_controller_parameters(pl022, chip_info);
if (status) {
dev_err(&spi->dev, "controller data is incorrect");
goto err_config_params;
}
pl022->rx_lev_trig = chip_info->rx_lev_trig;
pl022->tx_lev_trig = chip_info->tx_lev_trig;
/* Now set controller state based on controller data */
chip->xfer_type = chip_info->com_mode;
if (!chip_info->cs_control) {
chip->cs_control = null_cs_control;
if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
dev_warn(&spi->dev,
"invalid chip select\n");
} else
chip->cs_control = chip_info->cs_control;
/* Check bits per word with vendor specific range */
if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
status = -ENOTSUPP;
dev_err(&spi->dev, "illegal data size for this controller!\n");
dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
pl022->vendor->max_bpw);
goto err_config_params;
} else if (bits <= 8) {
dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
chip->n_bytes = 1;
chip->read = READING_U8;
chip->write = WRITING_U8;
} else if (bits <= 16) {
dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
chip->n_bytes = 2;
chip->read = READING_U16;
chip->write = WRITING_U16;
} else {
dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
chip->n_bytes = 4;
chip->read = READING_U32;
chip->write = WRITING_U32;
}
/* Now Initialize all register settings required for this chip */
chip->cr0 = 0;
chip->cr1 = 0;
chip->dmacr = 0;
chip->cpsr = 0;
if ((chip_info->com_mode == DMA_TRANSFER)
&& ((pl022->master_info)->enable_dma)) {
chip->enable_dma = true;
dev_dbg(&spi->dev, "DMA mode set in controller state\n");
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_RXDMAE, 0);
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_TXDMAE, 1);
} else {
chip->enable_dma = false;
dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_RXDMAE, 0);
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_TXDMAE, 1);
}
chip->cpsr = clk_freq.cpsdvsr;
/* Special setup for the ST micro extended control registers */
if (pl022->vendor->extended_cr) {
u32 etx;
if (pl022->vendor->pl023) {
/* These bits are only in the PL023 */
SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
SSP_CR1_MASK_FBCLKDEL_ST, 13);
} else {
/* These bits are in the PL022 but not PL023 */
SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
SSP_CR0_MASK_HALFDUP_ST, 5);
SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
SSP_CR0_MASK_CSS_ST, 16);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF_ST, 21);
SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
SSP_CR1_MASK_MWAIT_ST, 6);
}
SSP_WRITE_BITS(chip->cr0, bits - 1,
SSP_CR0_MASK_DSS_ST, 0);
if (spi->mode & SPI_LSB_FIRST) {
tmp = SSP_RX_LSB;
etx = SSP_TX_LSB;
} else {
tmp = SSP_RX_MSB;
etx = SSP_TX_MSB;
}
SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
SSP_CR1_MASK_RXIFLSEL_ST, 7);
SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
SSP_CR1_MASK_TXIFLSEL_ST, 10);
} else {
SSP_WRITE_BITS(chip->cr0, bits - 1,
SSP_CR0_MASK_DSS, 0);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF, 4);
}
/* Stuff that is common for all versions */
if (spi->mode & SPI_CPOL)
tmp = SSP_CLK_POL_IDLE_HIGH;
else
tmp = SSP_CLK_POL_IDLE_LOW;
SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
if (spi->mode & SPI_CPHA)
tmp = SSP_CLK_SECOND_EDGE;
else
tmp = SSP_CLK_FIRST_EDGE;
SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
/* Loopback is available on all versions except PL023 */
if (pl022->vendor->loopback) {
if (spi->mode & SPI_LOOP)
tmp = LOOPBACK_ENABLED;
else
tmp = LOOPBACK_DISABLED;
SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
}
SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
3);
/* Save controller_state */
spi_set_ctldata(spi, chip);
return status;
err_config_params:
spi_set_ctldata(spi, NULL);
kfree(chip);
return status;
}
/**
* pl022_cleanup - cleanup function registered to SPI master framework
* @spi: spi device which is requesting cleanup
*
* This function is registered to the SPI framework for this SPI master
* controller. It will free the runtime state of chip.
*/
static void pl022_cleanup(struct spi_device *spi)
{
struct chip_data *chip = spi_get_ctldata(spi);
spi_set_ctldata(spi, NULL);
kfree(chip);
}
static struct pl022_ssp_controller *
pl022_platform_data_dt_get(struct device *dev)
{
struct device_node *np = dev->of_node;
struct pl022_ssp_controller *pd;
u32 tmp = 0;
if (!np) {
dev_err(dev, "no dt node defined\n");
return NULL;
}
pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
if (!pd)
return NULL;
pd->bus_id = -1;
pd->enable_dma = 1;
of_property_read_u32(np, "num-cs", &tmp);
pd->num_chipselect = tmp;
of_property_read_u32(np, "pl022,autosuspend-delay",
&pd->autosuspend_delay);
pd->rt = of_property_read_bool(np, "pl022,rt");
return pd;
}
static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device *dev = &adev->dev;
struct pl022_ssp_controller *platform_info =
dev_get_platdata(&adev->dev);
struct spi_master *master;
struct pl022 *pl022 = NULL; /*Data for this driver */
struct device_node *np = adev->dev.of_node;
int status = 0, i, num_cs;
dev_info(&adev->dev,
"ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
if (!platform_info && IS_ENABLED(CONFIG_OF))
platform_info = pl022_platform_data_dt_get(dev);
if (!platform_info) {
dev_err(dev, "probe: no platform data defined\n");
return -ENODEV;
}
if (platform_info->num_chipselect) {
num_cs = platform_info->num_chipselect;
} else {
dev_err(dev, "probe: no chip select defined\n");
return -ENODEV;
}
/* Allocate master with space for data */
master = spi_alloc_master(dev, sizeof(struct pl022));
if (master == NULL) {
dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
return -ENOMEM;
}
pl022 = spi_master_get_devdata(master);
pl022->master = master;
pl022->master_info = platform_info;
pl022->adev = adev;
pl022->vendor = id->data;
pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
GFP_KERNEL);
if (!pl022->chipselects) {
status = -ENOMEM;
goto err_no_mem;
}
/*
* Bus Number Which has been Assigned to this SSP controller
* on this board
*/
master->bus_num = platform_info->bus_id;
master->num_chipselect = num_cs;
master->cleanup = pl022_cleanup;
master->setup = pl022_setup;
master->auto_runtime_pm = true;
master->transfer_one_message = pl022_transfer_one_message;
master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
master->rt = platform_info->rt;
master->dev.of_node = dev->of_node;
if (platform_info->num_chipselect && platform_info->chipselects) {
for (i = 0; i < num_cs; i++)
pl022->chipselects[i] = platform_info->chipselects[i];
} else if (pl022->vendor->internal_cs_ctrl) {
for (i = 0; i < num_cs; i++)
pl022->chipselects[i] = i;
} else if (IS_ENABLED(CONFIG_OF)) {
for (i = 0; i < num_cs; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
if (cs_gpio == -EPROBE_DEFER) {
status = -EPROBE_DEFER;
goto err_no_gpio;
}
pl022->chipselects[i] = cs_gpio;
if (gpio_is_valid(cs_gpio)) {
if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
dev_err(&adev->dev,
"could not request %d gpio\n",
cs_gpio);
else if (gpio_direction_output(cs_gpio, 1))
dev_err(&adev->dev,
"could not set gpio %d as output\n",
cs_gpio);
}
}
}
/*
* Supports mode 0-3, loopback, and active low CS. Transfers are
* always MS bit first on the original pl022.
*/
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
if (pl022->vendor->extended_cr)
master->mode_bits |= SPI_LSB_FIRST;
dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
status = amba_request_regions(adev, NULL);
if (status)
goto err_no_ioregion;
pl022->phybase = adev->res.start;
pl022->virtbase = devm_ioremap(dev, adev->res.start,
resource_size(&adev->res));
if (pl022->virtbase == NULL) {
status = -ENOMEM;
goto err_no_ioremap;
}
dev_info(&adev->dev, "mapped registers from %pa to %p\n",
&adev->res.start, pl022->virtbase);
pl022->clk = devm_clk_get(&adev->dev, NULL);
if (IS_ERR(pl022->clk)) {
status = PTR_ERR(pl022->clk);
dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
goto err_no_clk;
}
status = clk_prepare_enable(pl022->clk);
if (status) {
dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
goto err_no_clk_en;
}
/* Initialize transfer pump */
tasklet_init(&pl022->pump_transfers, pump_transfers,
(unsigned long)pl022);
/* Disable SSP */
writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
SSP_CR1(pl022->virtbase));
load_ssp_default_config(pl022);
status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
0, "pl022", pl022);
if (status < 0) {
dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
goto err_no_irq;
}
/* Get DMA channels, try autoconfiguration first */
status = pl022_dma_autoprobe(pl022);
if (status == -EPROBE_DEFER) {
dev_dbg(dev, "deferring probe to get DMA channel\n");
goto err_no_irq;
}
/* If that failed, use channels from platform_info */
if (status == 0)
platform_info->enable_dma = 1;
else if (platform_info->enable_dma) {
status = pl022_dma_probe(pl022);
if (status != 0)
platform_info->enable_dma = 0;
}
/* Register with the SPI framework */
amba_set_drvdata(adev, pl022);
status = devm_spi_register_master(&adev->dev, master);
if (status != 0) {
dev_err(&adev->dev,
"probe - problem registering spi master\n");
goto err_spi_register;
}
dev_dbg(dev, "probe succeeded\n");
/* let runtime pm put suspend */
if (platform_info->autosuspend_delay > 0) {
dev_info(&adev->dev,
"will use autosuspend for runtime pm, delay %dms\n",
platform_info->autosuspend_delay);
pm_runtime_set_autosuspend_delay(dev,
platform_info->autosuspend_delay);
pm_runtime_use_autosuspend(dev);
}
pm_runtime_put(dev);
return 0;
err_spi_register:
if (platform_info->enable_dma)
pl022_dma_remove(pl022);
err_no_irq:
clk_disable_unprepare(pl022->clk);
err_no_clk_en:
err_no_clk:
err_no_ioremap:
amba_release_regions(adev);
err_no_ioregion:
err_no_gpio:
err_no_mem:
spi_master_put(master);
return status;
}
static int
pl022_remove(struct amba_device *adev)
{
struct pl022 *pl022 = amba_get_drvdata(adev);
if (!pl022)
return 0;
/*
* undo pm_runtime_put() in probe. I assume that we're not
* accessing the primecell here.
*/
pm_runtime_get_noresume(&adev->dev);
load_ssp_default_config(pl022);
if (pl022->master_info->enable_dma)
pl022_dma_remove(pl022);
clk_disable_unprepare(pl022->clk);
amba_release_regions(adev);
tasklet_disable(&pl022->pump_transfers);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int pl022_suspend(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
int ret;
ret = spi_master_suspend(pl022->master);
if (ret) {
dev_warn(dev, "cannot suspend master\n");
return ret;
}
ret = pm_runtime_force_suspend(dev);
if (ret) {
spi_master_resume(pl022->master);
return ret;
}
pinctrl_pm_select_sleep_state(dev);
dev_dbg(dev, "suspended\n");
return 0;
}
static int pl022_resume(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_force_resume(dev);
if (ret)
dev_err(dev, "problem resuming\n");
/* Start the queue running */
ret = spi_master_resume(pl022->master);
if (ret)
dev_err(dev, "problem starting queue (%d)\n", ret);
else
dev_dbg(dev, "resumed\n");
return ret;
}
#endif
#ifdef CONFIG_PM
static int pl022_runtime_suspend(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
clk_disable_unprepare(pl022->clk);
pinctrl_pm_select_idle_state(dev);
return 0;
}
static int pl022_runtime_resume(struct device *dev)
{
struct pl022 *pl022 = dev_get_drvdata(dev);
pinctrl_pm_select_default_state(dev);
clk_prepare_enable(pl022->clk);
return 0;
}
#endif
static const struct dev_pm_ops pl022_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
};
static struct vendor_data vendor_arm = {
.fifodepth = 8,
.max_bpw = 16,
.unidir = false,
.extended_cr = false,
.pl023 = false,
.loopback = true,
.internal_cs_ctrl = false,
};
static struct vendor_data vendor_st = {
.fifodepth = 32,
.max_bpw = 32,
.unidir = false,
.extended_cr = true,
.pl023 = false,
.loopback = true,
.internal_cs_ctrl = false,
};
static struct vendor_data vendor_st_pl023 = {
.fifodepth = 32,
.max_bpw = 32,
.unidir = false,
.extended_cr = true,
.pl023 = true,
.loopback = false,
.internal_cs_ctrl = false,
};
static struct vendor_data vendor_lsi = {
.fifodepth = 8,
.max_bpw = 16,
.unidir = false,
.extended_cr = false,
.pl023 = false,
.loopback = true,
.internal_cs_ctrl = true,
};
static const struct amba_id pl022_ids[] = {
{
/*
* ARM PL022 variant, this has a 16bit wide
* and 8 locations deep TX/RX FIFO
*/
.id = 0x00041022,
.mask = 0x000fffff,
.data = &vendor_arm,
},
{
/*
* ST Micro derivative, this has 32bit wide
* and 32 locations deep TX/RX FIFO
*/
.id = 0x01080022,
.mask = 0xffffffff,
.data = &vendor_st,
},
{
/*
* ST-Ericsson derivative "PL023" (this is not
* an official ARM number), this is a PL022 SSP block
* stripped to SPI mode only, it has 32bit wide
* and 32 locations deep TX/RX FIFO but no extended
* CR0/CR1 register
*/
.id = 0x00080023,
.mask = 0xffffffff,
.data = &vendor_st_pl023,
},
{
/*
* PL022 variant that has a chip select control register whih
* allows control of 5 output signals nCS[0:4].
*/
.id = 0x000b6022,
.mask = 0x000fffff,
.data = &vendor_lsi,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl022_ids);
static struct amba_driver pl022_driver = {
.drv = {
.name = "ssp-pl022",
.pm = &pl022_dev_pm_ops,
},
.id_table = pl022_ids,
.probe = pl022_probe,
.remove = pl022_remove,
};
static int __init pl022_init(void)
{
return amba_driver_register(&pl022_driver);
}
subsys_initcall(pl022_init);
static void __exit pl022_exit(void)
{
amba_driver_unregister(&pl022_driver);
}
module_exit(pl022_exit);
MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("PL022 SSP Controller Driver");
MODULE_LICENSE("GPL");
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