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* drivers/spi/spi_imx.c
*
* Copyright (C) 2006 SWAPP
* Andrea Paterniani <a.paterniani@swapp-eng.it>
*
* Initial version inspired by:
* linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
*
* 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/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <mach/hardware.h>
#include <mach/imx-dma.h>
#include <mach/spi_imx.h>
/*-------------------------------------------------------------------------*/
/* SPI Registers offsets from peripheral base address */
#define SPI_RXDATA (0x00)
#define SPI_TXDATA (0x04)
#define SPI_CONTROL (0x08)
#define SPI_INT_STATUS (0x0C)
#define SPI_TEST (0x10)
#define SPI_PERIOD (0x14)
#define SPI_DMA (0x18)
#define SPI_RESET (0x1C)
/* SPI Control Register Bit Fields & Masks */
#define SPI_CONTROL_BITCOUNT_MASK (0xF) /* Bit Count Mask */
#define SPI_CONTROL_BITCOUNT(n) (((n) - 1) & SPI_CONTROL_BITCOUNT_MASK)
#define SPI_CONTROL_POL (0x1 << 4) /* Clock Polarity Mask */
#define SPI_CONTROL_POL_ACT_HIGH (0x0 << 4) /* Active high pol. (0=idle) */
#define SPI_CONTROL_POL_ACT_LOW (0x1 << 4) /* Active low pol. (1=idle) */
#define SPI_CONTROL_PHA (0x1 << 5) /* Clock Phase Mask */
#define SPI_CONTROL_PHA_0 (0x0 << 5) /* Clock Phase 0 */
#define SPI_CONTROL_PHA_1 (0x1 << 5) /* Clock Phase 1 */
#define SPI_CONTROL_SSCTL (0x1 << 6) /* /SS Waveform Select Mask */
#define SPI_CONTROL_SSCTL_0 (0x0 << 6) /* Master: /SS stays low between SPI burst
Slave: RXFIFO advanced by BIT_COUNT */
#define SPI_CONTROL_SSCTL_1 (0x1 << 6) /* Master: /SS insert pulse between SPI burst
Slave: RXFIFO advanced by /SS rising edge */
#define SPI_CONTROL_SSPOL (0x1 << 7) /* /SS Polarity Select Mask */
#define SPI_CONTROL_SSPOL_ACT_LOW (0x0 << 7) /* /SS Active low */
#define SPI_CONTROL_SSPOL_ACT_HIGH (0x1 << 7) /* /SS Active high */
#define SPI_CONTROL_XCH (0x1 << 8) /* Exchange */
#define SPI_CONTROL_SPIEN (0x1 << 9) /* SPI Module Enable */
#define SPI_CONTROL_MODE (0x1 << 10) /* SPI Mode Select Mask */
#define SPI_CONTROL_MODE_SLAVE (0x0 << 10) /* SPI Mode Slave */
#define SPI_CONTROL_MODE_MASTER (0x1 << 10) /* SPI Mode Master */
#define SPI_CONTROL_DRCTL (0x3 << 11) /* /SPI_RDY Control Mask */
#define SPI_CONTROL_DRCTL_0 (0x0 << 11) /* Ignore /SPI_RDY */
#define SPI_CONTROL_DRCTL_1 (0x1 << 11) /* /SPI_RDY falling edge triggers input */
#define SPI_CONTROL_DRCTL_2 (0x2 << 11) /* /SPI_RDY active low level triggers input */
#define SPI_CONTROL_DATARATE (0x7 << 13) /* Data Rate Mask */
#define SPI_PERCLK2_DIV_MIN (0) /* PERCLK2:4 */
#define SPI_PERCLK2_DIV_MAX (7) /* PERCLK2:512 */
#define SPI_CONTROL_DATARATE_MIN (SPI_PERCLK2_DIV_MAX << 13)
#define SPI_CONTROL_DATARATE_MAX (SPI_PERCLK2_DIV_MIN << 13)
#define SPI_CONTROL_DATARATE_BAD (SPI_CONTROL_DATARATE_MIN + 1)
/* SPI Interrupt/Status Register Bit Fields & Masks */
#define SPI_STATUS_TE (0x1 << 0) /* TXFIFO Empty Status */
#define SPI_STATUS_TH (0x1 << 1) /* TXFIFO Half Status */
#define SPI_STATUS_TF (0x1 << 2) /* TXFIFO Full Status */
#define SPI_STATUS_RR (0x1 << 3) /* RXFIFO Data Ready Status */
#define SPI_STATUS_RH (0x1 << 4) /* RXFIFO Half Status */
#define SPI_STATUS_RF (0x1 << 5) /* RXFIFO Full Status */
#define SPI_STATUS_RO (0x1 << 6) /* RXFIFO Overflow */
#define SPI_STATUS_BO (0x1 << 7) /* Bit Count Overflow */
#define SPI_STATUS (0xFF) /* SPI Status Mask */
#define SPI_INTEN_TE (0x1 << 8) /* TXFIFO Empty Interrupt Enable */
#define SPI_INTEN_TH (0x1 << 9) /* TXFIFO Half Interrupt Enable */
#define SPI_INTEN_TF (0x1 << 10) /* TXFIFO Full Interrupt Enable */
#define SPI_INTEN_RE (0x1 << 11) /* RXFIFO Data Ready Interrupt Enable */
#define SPI_INTEN_RH (0x1 << 12) /* RXFIFO Half Interrupt Enable */
#define SPI_INTEN_RF (0x1 << 13) /* RXFIFO Full Interrupt Enable */
#define SPI_INTEN_RO (0x1 << 14) /* RXFIFO Overflow Interrupt Enable */
#define SPI_INTEN_BO (0x1 << 15) /* Bit Count Overflow Interrupt Enable */
#define SPI_INTEN (0xFF << 8) /* SPI Interrupt Enable Mask */
/* SPI Test Register Bit Fields & Masks */
#define SPI_TEST_TXCNT (0xF << 0) /* TXFIFO Counter */
#define SPI_TEST_RXCNT_LSB (4) /* RXFIFO Counter LSB */
#define SPI_TEST_RXCNT (0xF << 4) /* RXFIFO Counter */
#define SPI_TEST_SSTATUS (0xF << 8) /* State Machine Status */
#define SPI_TEST_LBC (0x1 << 14) /* Loop Back Control */
/* SPI Period Register Bit Fields & Masks */
#define SPI_PERIOD_WAIT (0x7FFF << 0) /* Wait Between Transactions */
#define SPI_PERIOD_MAX_WAIT (0x7FFF) /* Max Wait Between
Transactions */
#define SPI_PERIOD_CSRC (0x1 << 15) /* Period Clock Source Mask */
#define SPI_PERIOD_CSRC_BCLK (0x0 << 15) /* Period Clock Source is
Bit Clock */
#define SPI_PERIOD_CSRC_32768 (0x1 << 15) /* Period Clock Source is
32.768 KHz Clock */
/* SPI DMA Register Bit Fields & Masks */
#define SPI_DMA_RHDMA (0x1 << 4) /* RXFIFO Half Status */
#define SPI_DMA_RFDMA (0x1 << 5) /* RXFIFO Full Status */
#define SPI_DMA_TEDMA (0x1 << 6) /* TXFIFO Empty Status */
#define SPI_DMA_THDMA (0x1 << 7) /* TXFIFO Half Status */
#define SPI_DMA_RHDEN (0x1 << 12) /* RXFIFO Half DMA Request Enable */
#define SPI_DMA_RFDEN (0x1 << 13) /* RXFIFO Full DMA Request Enable */
#define SPI_DMA_TEDEN (0x1 << 14) /* TXFIFO Empty DMA Request Enable */
#define SPI_DMA_THDEN (0x1 << 15) /* TXFIFO Half DMA Request Enable */
/* SPI Soft Reset Register Bit Fields & Masks */
#define SPI_RESET_START (0x1) /* Start */
/* Default SPI configuration values */
#define SPI_DEFAULT_CONTROL \
( \
SPI_CONTROL_BITCOUNT(16) | \
SPI_CONTROL_POL_ACT_HIGH | \
SPI_CONTROL_PHA_0 | \
SPI_CONTROL_SPIEN | \
SPI_CONTROL_SSCTL_1 | \
SPI_CONTROL_MODE_MASTER | \
SPI_CONTROL_DRCTL_0 | \
SPI_CONTROL_DATARATE_MIN \
)
#define SPI_DEFAULT_ENABLE_LOOPBACK (0)
#define SPI_DEFAULT_ENABLE_DMA (0)
#define SPI_DEFAULT_PERIOD_WAIT (8)
/*-------------------------------------------------------------------------*/
/*-------------------------------------------------------------------------*/
/* TX/RX SPI FIFO size */
#define SPI_FIFO_DEPTH (8)
#define SPI_FIFO_BYTE_WIDTH (2)
#define SPI_FIFO_OVERFLOW_MARGIN (2)
/* DMA burst length for half full/empty request trigger */
#define SPI_DMA_BLR (SPI_FIFO_DEPTH * SPI_FIFO_BYTE_WIDTH / 2)
/* Dummy char output to achieve reads.
Choosing something different from all zeroes may help pattern recogition
for oscilloscope analysis, but may break some drivers. */
#define SPI_DUMMY_u8 0
#define SPI_DUMMY_u16 ((SPI_DUMMY_u8 << 8) | SPI_DUMMY_u8)
#define SPI_DUMMY_u32 ((SPI_DUMMY_u16 << 16) | SPI_DUMMY_u16)
/**
* Macro to change a u32 field:
* @r : register to edit
* @m : bit mask
* @v : new value for the field correctly bit-alligned
*/
#define u32_EDIT(r, m, v) r = (r & ~(m)) | (v)
/* Message state */
#define START_STATE ((void*)0)
#define RUNNING_STATE ((void*)1)
#define DONE_STATE ((void*)2)
#define ERROR_STATE ((void*)-1)
/* Queue state */
#define QUEUE_RUNNING (0)
#define QUEUE_STOPPED (1)
#define IS_DMA_ALIGNED(x) (((u32)(x) & 0x03) == 0)
/*-------------------------------------------------------------------------*/
/*-------------------------------------------------------------------------*/
/* Driver data structs */
/* Context */
struct driver_data {
/* Driver model hookup */
struct platform_device *pdev;
/* SPI framework hookup */
struct spi_master *master;
/* IMX hookup */
struct spi_imx_master *master_info;
/* Memory resources and SPI regs virtual address */
struct resource *ioarea;
void __iomem *regs;
/* SPI RX_DATA physical address */
dma_addr_t rd_data_phys;
/* Driver message queue */
struct workqueue_struct *workqueue;
struct work_struct work;
spinlock_t lock;
struct list_head queue;
int busy;
int run;
/* Message Transfer pump */
struct tasklet_struct pump_transfers;
/* Current message, transfer and state */
struct spi_message *cur_msg;
struct spi_transfer *cur_transfer;
struct chip_data *cur_chip;
/* Rd / Wr buffers pointers */
size_t len;
void *tx;
void *tx_end;
void *rx;
void *rx_end;
u8 rd_only;
u8 n_bytes;
int cs_change;
/* Function pointers */
irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
void (*cs_control)(u32 command);
/* DMA setup */
int rx_channel;
int tx_channel;
dma_addr_t rx_dma;
dma_addr_t tx_dma;
int rx_dma_needs_unmap;
int tx_dma_needs_unmap;
size_t tx_map_len;
u32 dummy_dma_buf ____cacheline_aligned;
struct clk *clk;
};
/* Runtime state */
struct chip_data {
u32 control;
u32 period;
u32 test;
u8 enable_dma:1;
u8 bits_per_word;
u8 n_bytes;
u32 max_speed_hz;
void (*cs_control)(u32 command);
};
/*-------------------------------------------------------------------------*/
static void pump_messages(struct work_struct *work);
static void flush(struct driver_data *drv_data)
{
void __iomem *regs = drv_data->regs;
u32 control;
dev_dbg(&drv_data->pdev->dev, "flush\n");
/* Wait for end of transaction */
do {
control = readl(regs + SPI_CONTROL);
} while (control & SPI_CONTROL_XCH);
/* Release chip select if requested, transfer delays are
handled in pump_transfers */
if (drv_data->cs_change)
drv_data->cs_control(SPI_CS_DEASSERT);
/* Disable SPI to flush FIFOs */
writel(control & ~SPI_CONTROL_SPIEN, regs + SPI_CONTROL);
writel(control, regs + SPI_CONTROL);
}
static void restore_state(struct driver_data *drv_data)
{
void __iomem *regs = drv_data->regs;
struct chip_data *chip = drv_data->cur_chip;
/* Load chip registers */
dev_dbg(&drv_data->pdev->dev,
"restore_state\n"
" test = 0x%08X\n"
" control = 0x%08X\n",
chip->test,
chip->control);
writel(chip->test, regs + SPI_TEST);
writel(chip->period, regs + SPI_PERIOD);
writel(0, regs + SPI_INT_STATUS);
writel(chip->control, regs + SPI_CONTROL);
}
static void null_cs_control(u32 command)
{
}
static inline u32 data_to_write(struct driver_data *drv_data)
{
return ((u32)(drv_data->tx_end - drv_data->tx)) / drv_data->n_bytes;
}
static inline u32 data_to_read(struct driver_data *drv_data)
{
return ((u32)(drv_data->rx_end - drv_data->rx)) / drv_data->n_bytes;
}
static int write(struct driver_data *drv_data)
{
void __iomem *regs = drv_data->regs;
void *tx = drv_data->tx;
void *tx_end = drv_data->tx_end;
u8 n_bytes = drv_data->n_bytes;
u32 remaining_writes;
u32 fifo_avail_space;
u32 n;
u16 d;
/* Compute how many fifo writes to do */
remaining_writes = (u32)(tx_end - tx) / n_bytes;
fifo_avail_space = SPI_FIFO_DEPTH -
(readl(regs + SPI_TEST) & SPI_TEST_TXCNT);
if (drv_data->rx && (fifo_avail_space > SPI_FIFO_OVERFLOW_MARGIN))
/* Fix misunderstood receive overflow */
fifo_avail_space -= SPI_FIFO_OVERFLOW_MARGIN;
n = min(remaining_writes, fifo_avail_space);
dev_dbg(&drv_data->pdev->dev,
"write type %s\n"
" remaining writes = %d\n"
" fifo avail space = %d\n"
" fifo writes = %d\n",
(n_bytes == 1) ? "u8" : "u16",
remaining_writes,
fifo_avail_space,
n);
if (n > 0) {
/* Fill SPI TXFIFO */
if (drv_data->rd_only) {
tx += n * n_bytes;
while (n--)
writel(SPI_DUMMY_u16, regs + SPI_TXDATA);
} else {
if (n_bytes == 1) {
while (n--) {
d = *(u8*)tx;
writel(d, regs + SPI_TXDATA);
tx += 1;
}
} else {
while (n--) {
d = *(u16*)tx;
writel(d, regs + SPI_TXDATA);
tx += 2;
}
}
}
/* Trigger transfer */
writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
regs + SPI_CONTROL);
/* Update tx pointer */
drv_data->tx = tx;
}
return (tx >= tx_end);
}
static int read(struct driver_data *drv_data)
{
void __iomem *regs = drv_data->regs;
void *rx = drv_data->rx;
void *rx_end = drv_data->rx_end;
u8 n_bytes = drv_data->n_bytes;
u32 remaining_reads;
u32 fifo_rxcnt;
u32 n;
u16 d;
/* Compute how many fifo reads to do */
remaining_reads = (u32)(rx_end - rx) / n_bytes;
fifo_rxcnt = (readl(regs + SPI_TEST) & SPI_TEST_RXCNT) >>
SPI_TEST_RXCNT_LSB;
n = min(remaining_reads, fifo_rxcnt);
dev_dbg(&drv_data->pdev->dev,
"read type %s\n"
" remaining reads = %d\n"
" fifo rx count = %d\n"
" fifo reads = %d\n",
(n_bytes == 1) ? "u8" : "u16",
remaining_reads,
fifo_rxcnt,
n);
if (n > 0) {
/* Read SPI RXFIFO */
if (n_bytes == 1) {
while (n--) {
d = readl(regs + SPI_RXDATA);
*((u8*)rx) = d;
rx += 1;
}
} else {
while (n--) {
d = readl(regs + SPI_RXDATA);
*((u16*)rx) = d;
rx += 2;
}
}
/* Update rx pointer */
drv_data->rx = rx;
}
return (rx >= rx_end);
}
static void *next_transfer(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
struct spi_transfer *trans = drv_data->cur_transfer;
/* Move to next transfer */
if (trans->transfer_list.next != &msg->transfers) {
drv_data->cur_transfer =
list_entry(trans->transfer_list.next,
struct spi_transfer,
transfer_list);
return RUNNING_STATE;
}
return DONE_STATE;
}
static int map_dma_buffers(struct driver_data *drv_data)
{
struct spi_message *msg;
struct device *dev;
void *buf;
drv_data->rx_dma_needs_unmap = 0;
drv_data->tx_dma_needs_unmap = 0;
if (!drv_data->master_info->enable_dma ||
!drv_data->cur_chip->enable_dma)
return -1;
msg = drv_data->cur_msg;
dev = &msg->spi->dev;
if (msg->is_dma_mapped) {
if (drv_data->tx_dma)
/* The caller provided at least dma and cpu virtual
address for write; pump_transfers() will consider the
transfer as write only if cpu rx virtual address is
NULL */
return 0;
if (drv_data->rx_dma) {
/* The caller provided dma and cpu virtual address to
performe read only transfer -->
use drv_data->dummy_dma_buf for dummy writes to
achive reads */
buf = &drv_data->dummy_dma_buf;
drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
drv_data->tx_dma = dma_map_single(dev,
buf,
drv_data->tx_map_len,
DMA_TO_DEVICE);
if (dma_mapping_error(dev, drv_data->tx_dma))
return -1;
drv_data->tx_dma_needs_unmap = 1;
/* Flags transfer as rd_only for pump_transfers() DMA
regs programming (should be redundant) */
drv_data->tx = NULL;
return 0;
}
}
if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
return -1;
if (drv_data->tx == NULL) {
/* Read only message --> use drv_data->dummy_dma_buf for dummy
writes to achive reads */
buf = &drv_data->dummy_dma_buf;
drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
} else {
buf = drv_data->tx;
drv_data->tx_map_len = drv_data->len;
}
drv_data->tx_dma = dma_map_single(dev,
buf,
drv_data->tx_map_len,
DMA_TO_DEVICE);
if (dma_mapping_error(dev, drv_data->tx_dma))
return -1;
drv_data->tx_dma_needs_unmap = 1;
/* NULL rx means write-only transfer and no map needed
* since rx DMA will not be used */
if (drv_data->rx) {
buf = drv_data->rx;
drv_data->rx_dma = dma_map_single(dev,
buf,
drv_data->len,
DMA_FROM_DEVICE);
if (dma_mapping_error(dev, drv_data->rx_dma)) {
if (drv_data->tx_dma) {
dma_unmap_single(dev,
drv_data->tx_dma,
drv_data->tx_map_len,
DMA_TO_DEVICE);
drv_data->tx_dma_needs_unmap = 0;
}
return -1;
}
drv_data->rx_dma_needs_unmap = 1;
}
return 0;
}
static void unmap_dma_buffers(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
struct device *dev = &msg->spi->dev;
if (drv_data->rx_dma_needs_unmap) {
dma_unmap_single(dev,
drv_data->rx_dma,
drv_data->len,
DMA_FROM_DEVICE);
drv_data->rx_dma_needs_unmap = 0;
}
if (drv_data->tx_dma_needs_unmap) {
dma_unmap_single(dev,
drv_data->tx_dma,
drv_data->tx_map_len,
DMA_TO_DEVICE);
drv_data->tx_dma_needs_unmap = 0;
}
}
/* Caller already set message->status (dma is already blocked) */
static void giveback(struct spi_message *message, struct driver_data *drv_data)
{
void __iomem *regs = drv_data->regs;
/* Bring SPI to sleep; restore_state() and pump_transfer()
will do new setup */
writel(0, regs + SPI_INT_STATUS);
writel(0, regs + SPI_DMA);
/* Unconditioned deselct */
drv_data->cs_control(SPI_CS_DEASSERT);
message->state = NULL;
if (message->complete)
message->complete(message->context);
drv_data->cur_msg = NULL;
drv_data->cur_transfer = NULL;
drv_data->cur_chip = NULL;
queue_work(drv_data->workqueue, &drv_data->work);
}
static void dma_err_handler(int channel, void *data, int errcode)
{
struct driver_data *drv_data = data;
struct spi_message *msg = drv_data->cur_msg;
dev_dbg(&drv_data->pdev->dev, "dma_err_handler\n");
/* Disable both rx and tx dma channels */
imx_dma_disable(drv_data->rx_channel);
imx_dma_disable(drv_data->tx_channel);
unmap_dma_buffers(drv_data);
flush(drv_data);
msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
}
static void dma_tx_handler(int channel, void *data)
{
struct driver_data *drv_data = data;
dev_dbg(&drv_data->pdev->dev, "dma_tx_handler\n");
imx_dma_disable(channel);
/* Now waits for TX FIFO empty */
writel(SPI_INTEN_TE, drv_data->regs + SPI_INT_STATUS);
}
static irqreturn_t dma_transfer(struct driver_data *drv_data)
{
u32 status;
struct spi_message *msg = drv_data->cur_msg;
void __iomem *regs = drv_data->regs;
status = readl(regs + SPI_INT_STATUS);
if ((status & (SPI_INTEN_RO | SPI_STATUS_RO))
== (SPI_INTEN_RO | SPI_STATUS_RO)) {
writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
imx_dma_disable(drv_data->tx_channel);
imx_dma_disable(drv_data->rx_channel);
unmap_dma_buffers(drv_data);
flush(drv_data);
dev_warn(&drv_data->pdev->dev,
"dma_transfer - fifo overun\n");
msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
return IRQ_HANDLED;
}
if (status & SPI_STATUS_TE) {
writel(status & ~SPI_INTEN_TE, regs + SPI_INT_STATUS);
if (drv_data->rx) {
/* Wait end of transfer before read trailing data */
while (readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH)
cpu_relax();
imx_dma_disable(drv_data->rx_channel);
unmap_dma_buffers(drv_data);
/* Release chip select if requested, transfer delays are
handled in pump_transfers() */
if (drv_data->cs_change)
drv_data->cs_control(SPI_CS_DEASSERT);
/* Calculate number of trailing data and read them */
dev_dbg(&drv_data->pdev->dev,
"dma_transfer - test = 0x%08X\n",
readl(regs + SPI_TEST));
drv_data->rx = drv_data->rx_end -
((readl(regs + SPI_TEST) &
SPI_TEST_RXCNT) >>
SPI_TEST_RXCNT_LSB)*drv_data->n_bytes;
read(drv_data);
} else {
/* Write only transfer */
unmap_dma_buffers(drv_data);
flush(drv_data);
}
/* End of transfer, update total byte transfered */
msg->actual_length += drv_data->len;
/* Move to next transfer */
msg->state = next_transfer(drv_data);
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
return IRQ_HANDLED;
}
/* Opps problem detected */
return IRQ_NONE;
}
static irqreturn_t interrupt_wronly_transfer(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
void __iomem *regs = drv_data->regs;
u32 status;
irqreturn_t handled = IRQ_NONE;
status = readl(regs + SPI_INT_STATUS);
if (status & SPI_INTEN_TE) {
/* TXFIFO Empty Interrupt on the last transfered word */
writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
dev_dbg(&drv_data->pdev->dev,
"interrupt_wronly_transfer - end of tx\n");
flush(drv_data);
/* Update total byte transfered */
msg->actual_length += drv_data->len;
/* Move to next transfer */
msg->state = next_transfer(drv_data);
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
return IRQ_HANDLED;
} else {
while (status & SPI_STATUS_TH) {
dev_dbg(&drv_data->pdev->dev,
"interrupt_wronly_transfer - status = 0x%08X\n",
status);
/* Pump data */
if (write(drv_data)) {
/* End of TXFIFO writes,
now wait until TXFIFO is empty */
writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
return IRQ_HANDLED;
}
status = readl(regs + SPI_INT_STATUS);
/* We did something */
handled = IRQ_HANDLED;
}
}
return handled;
}
static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
void __iomem *regs = drv_data->regs;
u32 status, control;
irqreturn_t handled = IRQ_NONE;
unsigned long limit;
status = readl(regs + SPI_INT_STATUS);
if (status & SPI_INTEN_TE) {
/* TXFIFO Empty Interrupt on the last transfered word */
writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
dev_dbg(&drv_data->pdev->dev,
"interrupt_transfer - end of tx\n");
if (msg->state == ERROR_STATE) {
/* RXFIFO overrun was detected and message aborted */
flush(drv_data);
} else {
/* Wait for end of transaction */
do {
control = readl(regs + SPI_CONTROL);
} while (control & SPI_CONTROL_XCH);
/* Release chip select if requested, transfer delays are
handled in pump_transfers */
if (drv_data->cs_change)
drv_data->cs_control(SPI_CS_DEASSERT);
/* Read trailing bytes */
limit = loops_per_jiffy << 1;
while ((read(drv_data) == 0) && limit--);
if (limit == 0)
dev_err(&drv_data->pdev->dev,
"interrupt_transfer - "
"trailing byte read failed\n");
else
dev_dbg(&drv_data->pdev->dev,
"interrupt_transfer - end of rx\n");
/* Update total byte transfered */
msg->actual_length += drv_data->len;
/* Move to next transfer */
msg->state = next_transfer(drv_data);
}
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
return IRQ_HANDLED;
} else {
while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
dev_dbg(&drv_data->pdev->dev,
"interrupt_transfer - status = 0x%08X\n",
status);
if (status & SPI_STATUS_RO) {
/* RXFIFO overrun, abort message end wait
until TXFIFO is empty */
writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
dev_warn(&drv_data->pdev->dev,
"interrupt_transfer - fifo overun\n"
" data not yet written = %d\n"
" data not yet read = %d\n",
data_to_write(drv_data),
data_to_read(drv_data));
msg->state = ERROR_STATE;
return IRQ_HANDLED;
}
/* Pump data */
read(drv_data);
if (write(drv_data)) {
/* End of TXFIFO writes,
now wait until TXFIFO is empty */
writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
return IRQ_HANDLED;
}
status = readl(regs + SPI_INT_STATUS);
/* We did something */
handled = IRQ_HANDLED;
}
}
return handled;
}
static irqreturn_t spi_int(int irq, void *dev_id)
{
struct driver_data *drv_data = (struct driver_data *)dev_id;
if (!drv_data->cur_msg) {
dev_err(&drv_data->pdev->dev,
"spi_int - bad message state\n");
/* Never fail */
return IRQ_HANDLED;
}
return drv_data->transfer_handler(drv_data);
}
static inline u32 spi_speed_hz(struct driver_data *drv_data, u32 data_rate)
{
return clk_get_rate(drv_data->clk) / (4 << ((data_rate) >> 13));
}
static u32 spi_data_rate(struct driver_data *drv_data, u32 speed_hz)
{
u32 div;
u32 quantized_hz = clk_get_rate(drv_data->clk) >> 2;
for (div = SPI_PERCLK2_DIV_MIN;
div <= SPI_PERCLK2_DIV_MAX;
div++, quantized_hz >>= 1) {
if (quantized_hz <= speed_hz)
/* Max available speed LEQ required speed */
return div << 13;
}
return SPI_CONTROL_DATARATE_BAD;
}
static void pump_transfers(unsigned long data)
{
struct driver_data *drv_data = (struct driver_data *)data;
struct spi_message *message;
struct spi_transfer *transfer, *previous;
struct chip_data *chip;
void __iomem *regs;
u32 tmp, control;
dev_dbg(&drv_data->pdev->dev, "pump_transfer\n");
message = drv_data->cur_msg;
/* Handle for abort */
if (message->state == ERROR_STATE) {
message->status = -EIO;
giveback(message, drv_data);
return;
}
/* Handle end of message */
if (message->state == DONE_STATE) {
message->status = 0;
giveback(message, drv_data);
return;
}
chip = drv_data->cur_chip;
/* Delay if requested at end of transfer*/
transfer = drv_data->cur_transfer;
if (message->state == RUNNING_STATE) {
previous = list_entry(transfer->transfer_list.prev,
struct spi_transfer,
transfer_list);
if (previous->delay_usecs)
udelay(previous->delay_usecs);
} else {
/* START_STATE */
message->state = RUNNING_STATE;
drv_data->cs_control = chip->cs_control;
}
transfer = drv_data->cur_transfer;
drv_data->tx = (void *)transfer->tx_buf;
drv_data->tx_end = drv_data->tx + transfer->len;
drv_data->rx = transfer->rx_buf;
drv_data->rx_end = drv_data->rx + transfer->len;
drv_data->rx_dma = transfer->rx_dma;
drv_data->tx_dma = transfer->tx_dma;
drv_data->len = transfer->len;
drv_data->cs_change = transfer->cs_change;
drv_data->rd_only = (drv_data->tx == NULL);
regs = drv_data->regs;
control = readl(regs + SPI_CONTROL);
/* Bits per word setup */
tmp = transfer->bits_per_word;
if (tmp == 0) {
/* Use device setup */
tmp = chip->bits_per_word;
drv_data->n_bytes = chip->n_bytes;
} else
/* Use per-transfer setup */
drv_data->n_bytes = (tmp <= 8) ? 1 : 2;
u32_EDIT(control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
/* Speed setup (surely valid because already checked) */
tmp = transfer->speed_hz;
if (tmp == 0)
tmp = chip->max_speed_hz;
tmp = spi_data_rate(drv_data, tmp);
u32_EDIT(control, SPI_CONTROL_DATARATE, tmp);
writel(control, regs + SPI_CONTROL);
/* Assert device chip-select */
drv_data->cs_control(SPI_CS_ASSERT);
/* DMA cannot read/write SPI FIFOs other than 16 bits at a time; hence
if bits_per_word is less or equal 8 PIO transfers are performed.
Moreover DMA is convinient for transfer length bigger than FIFOs
byte size. */
if ((drv_data->n_bytes == 2) &&
(drv_data->len > SPI_FIFO_DEPTH*SPI_FIFO_BYTE_WIDTH) &&
(map_dma_buffers(drv_data) == 0)) {
dev_dbg(&drv_data->pdev->dev,
"pump dma transfer\n"
" tx = %p\n"
" tx_dma = %08X\n"
" rx = %p\n"
" rx_dma = %08X\n"
" len = %d\n",
drv_data->tx,
(unsigned int)drv_data->tx_dma,
drv_data->rx,
(unsigned int)drv_data->rx_dma,
drv_data->len);
/* Ensure we have the correct interrupt handler */
drv_data->transfer_handler = dma_transfer;
/* Trigger transfer */
writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
regs + SPI_CONTROL);
/* Setup tx DMA */
if (drv_data->tx)
/* Linear source address */
CCR(drv_data->tx_channel) =
CCR_DMOD_FIFO |
CCR_SMOD_LINEAR |
CCR_SSIZ_32 | CCR_DSIZ_16 |
CCR_REN;
else
/* Read only transfer -> fixed source address for
dummy write to achive read */
CCR(drv_data->tx_channel) =
CCR_DMOD_FIFO |
CCR_SMOD_FIFO |
CCR_SSIZ_32 | CCR_DSIZ_16 |
CCR_REN;
imx_dma_setup_single(
drv_data->tx_channel,
drv_data->tx_dma,
drv_data->len,
drv_data->rd_data_phys + 4,
DMA_MODE_WRITE);
if (drv_data->rx) {
/* Setup rx DMA for linear destination address */
CCR(drv_data->rx_channel) =
CCR_DMOD_LINEAR |
CCR_SMOD_FIFO |
CCR_DSIZ_32 | CCR_SSIZ_16 |
CCR_REN;
imx_dma_setup_single(
drv_data->rx_channel,
drv_data->rx_dma,
drv_data->len,
drv_data->rd_data_phys,
DMA_MODE_READ);
imx_dma_enable(drv_data->rx_channel);
/* Enable SPI interrupt */
writel(SPI_INTEN_RO, regs + SPI_INT_STATUS);
/* Set SPI to request DMA service on both
Rx and Tx half fifo watermark */
writel(SPI_DMA_RHDEN | SPI_DMA_THDEN, regs + SPI_DMA);
} else
/* Write only access -> set SPI to request DMA
service on Tx half fifo watermark */
writel(SPI_DMA_THDEN, regs + SPI_DMA);
imx_dma_enable(drv_data->tx_channel);
} else {
dev_dbg(&drv_data->pdev->dev,
"pump pio transfer\n"
" tx = %p\n"
" rx = %p\n"
" len = %d\n",
drv_data->tx,
drv_data->rx,
drv_data->len);
/* Ensure we have the correct interrupt handler */
if (drv_data->rx)
drv_data->transfer_handler = interrupt_transfer;
else
drv_data->transfer_handler = interrupt_wronly_transfer;
/* Enable SPI interrupt */
if (drv_data->rx)
writel(SPI_INTEN_TH | SPI_INTEN_RO,
regs + SPI_INT_STATUS);
else
writel(SPI_INTEN_TH, regs + SPI_INT_STATUS);
}
}
static void pump_messages(struct work_struct *work)
{
struct driver_data *drv_data =
container_of(work, struct driver_data, work);
unsigned long flags;
/* Lock queue and check for queue work */
spin_lock_irqsave(&drv_data->lock, flags);
if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
drv_data->busy = 0;
spin_unlock_irqrestore(&drv_data->lock, flags);
return;
}
/* Make sure we are not already running a message */
if (drv_data->cur_msg) {
spin_unlock_irqrestore(&drv_data->lock, flags);
return;
}
/* Extract head of queue */
drv_data->cur_msg = list_entry(drv_data->queue.next,
struct spi_message, queue);
list_del_init(&drv_data->cur_msg->queue);
drv_data->busy = 1;
spin_unlock_irqrestore(&drv_data->lock, flags);
/* Initial message state */
drv_data->cur_msg->state = START_STATE;
drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
struct spi_transfer,
transfer_list);
/* Setup the SPI using the per chip configuration */
drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
restore_state(drv_data);
/* Mark as busy and launch transfers */
tasklet_schedule(&drv_data->pump_transfers);
}
static int transfer(struct spi_device *spi, struct spi_message *msg)
{
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
u32 min_speed_hz, max_speed_hz, tmp;
struct spi_transfer *trans;
unsigned long flags;
msg->actual_length = 0;
/* Per transfer setup check */
min_speed_hz = spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN);
max_speed_hz = spi->max_speed_hz;
list_for_each_entry(trans, &msg->transfers, transfer_list) {
tmp = trans->bits_per_word;
if (tmp > 16) {
dev_err(&drv_data->pdev->dev,
"message rejected : "
"invalid transfer bits_per_word (%d bits)\n",
tmp);
goto msg_rejected;
}
tmp = trans->speed_hz;
if (tmp) {
if (tmp < min_speed_hz) {
dev_err(&drv_data->pdev->dev,
"message rejected : "
"device min speed (%d Hz) exceeds "
"required transfer speed (%d Hz)\n",
min_speed_hz,
tmp);
goto msg_rejected;
} else if (tmp > max_speed_hz) {
dev_err(&drv_data->pdev->dev,
"message rejected : "
"transfer speed (%d Hz) exceeds "
"device max speed (%d Hz)\n",
tmp,
max_speed_hz);
goto msg_rejected;
}
}
}
/* Message accepted */
msg->status = -EINPROGRESS;
msg->state = START_STATE;
spin_lock_irqsave(&drv_data->lock, flags);
if (drv_data->run == QUEUE_STOPPED) {
spin_unlock_irqrestore(&drv_data->lock, flags);
return -ESHUTDOWN;
}
list_add_tail(&msg->queue, &drv_data->queue);
if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
queue_work(drv_data->workqueue, &drv_data->work);
spin_unlock_irqrestore(&drv_data->lock, flags);
return 0;
msg_rejected:
/* Message rejected and not queued */
msg->status = -EINVAL;
msg->state = ERROR_STATE;
if (msg->complete)
msg->complete(msg->context);
return -EINVAL;
}
/* the spi->mode bits understood by this driver: */
#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
/* On first setup bad values must free chip_data memory since will cause
spi_new_device to fail. Bad value setup from protocol driver are simply not
applied and notified to the calling driver. */
static int setup(struct spi_device *spi)
{
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
struct spi_imx_chip *chip_info;
struct chip_data *chip;
int first_setup = 0;
u32 tmp;
int status = 0;
if (spi->mode & ~MODEBITS) {
dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
spi->mode & ~MODEBITS);
return -EINVAL;
}
/* Get controller data */
chip_info = spi->controller_data;
/* Get controller_state */
chip = spi_get_ctldata(spi);
if (chip == NULL) {
first_setup = 1;
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
if (!chip) {
dev_err(&spi->dev,
"setup - cannot allocate controller state\n");
return -ENOMEM;
}
chip->control = SPI_DEFAULT_CONTROL;
if (chip_info == NULL) {
/* spi_board_info.controller_data not is supplied */
chip_info = kzalloc(sizeof(struct spi_imx_chip),
GFP_KERNEL);
if (!chip_info) {
dev_err(&spi->dev,
"setup - "
"cannot allocate controller data\n");
status = -ENOMEM;
goto err_first_setup;
}
/* Set controller data default value */
chip_info->enable_loopback =
SPI_DEFAULT_ENABLE_LOOPBACK;
chip_info->enable_dma = SPI_DEFAULT_ENABLE_DMA;
chip_info->ins_ss_pulse = 1;
chip_info->bclk_wait = SPI_DEFAULT_PERIOD_WAIT;
chip_info->cs_control = null_cs_control;
}
}
/* Now set controller state based on controller data */
if (first_setup) {
/* SPI loopback */
if (chip_info->enable_loopback)
chip->test = SPI_TEST_LBC;
else
chip->test = 0;
/* SPI dma driven */
chip->enable_dma = chip_info->enable_dma;
/* SPI /SS pulse between spi burst */
if (chip_info->ins_ss_pulse)
u32_EDIT(chip->control,
SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_1);
else
u32_EDIT(chip->control,
SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_0);
/* SPI bclk waits between each bits_per_word spi burst */
if (chip_info->bclk_wait > SPI_PERIOD_MAX_WAIT) {
dev_err(&spi->dev,
"setup - "
"bclk_wait exceeds max allowed (%d)\n",
SPI_PERIOD_MAX_WAIT);
goto err_first_setup;
}
chip->period = SPI_PERIOD_CSRC_BCLK |
(chip_info->bclk_wait & SPI_PERIOD_WAIT);
}
/* SPI mode */
tmp = spi->mode;
if (tmp & SPI_CS_HIGH) {
u32_EDIT(chip->control,
SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);
}
switch (tmp & SPI_MODE_3) {
case SPI_MODE_0:
tmp = 0;
break;
case SPI_MODE_1:
tmp = SPI_CONTROL_PHA_1;
break;
case SPI_MODE_2:
tmp = SPI_CONTROL_POL_ACT_LOW;
break;
default:
/* SPI_MODE_3 */
tmp = SPI_CONTROL_PHA_1 | SPI_CONTROL_POL_ACT_LOW;
break;
}
u32_EDIT(chip->control, SPI_CONTROL_POL | SPI_CONTROL_PHA, tmp);
/* SPI word width */
tmp = spi->bits_per_word;
if (tmp == 0) {
tmp = 8;
spi->bits_per_word = 8;
} else if (tmp > 16) {
status = -EINVAL;
dev_err(&spi->dev,
"setup - "
"invalid bits_per_word (%d)\n",
tmp);
if (first_setup)
goto err_first_setup;
else {
/* Undo setup using chip as backup copy */
tmp = chip->bits_per_word;
spi->bits_per_word = tmp;
}
}
chip->bits_per_word = tmp;
u32_EDIT(chip->control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
chip->n_bytes = (tmp <= 8) ? 1 : 2;
/* SPI datarate */
tmp = spi_data_rate(drv_data, spi->max_speed_hz);
if (tmp == SPI_CONTROL_DATARATE_BAD) {
status = -EINVAL;
dev_err(&spi->dev,
"setup - "
"HW min speed (%d Hz) exceeds required "
"max speed (%d Hz)\n",
spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN),
spi->max_speed_hz);
if (first_setup)
goto err_first_setup;
else
/* Undo setup using chip as backup copy */
spi->max_speed_hz = chip->max_speed_hz;
} else {
u32_EDIT(chip->control, SPI_CONTROL_DATARATE, tmp);
/* Actual rounded max_speed_hz */
tmp = spi_speed_hz(drv_data, tmp);
spi->max_speed_hz = tmp;
chip->max_speed_hz = tmp;
}
/* SPI chip-select management */
if (chip_info->cs_control)
chip->cs_control = chip_info->cs_control;
else
chip->cs_control = null_cs_control;
/* Save controller_state */
spi_set_ctldata(spi, chip);
/* Summary */
dev_dbg(&spi->dev,
"setup succeded\n"
" loopback enable = %s\n"
" dma enable = %s\n"
" insert /ss pulse = %s\n"
" period wait = %d\n"
" mode = %d\n"
" bits per word = %d\n"
" min speed = %d Hz\n"
" rounded max speed = %d Hz\n",
chip->test & SPI_TEST_LBC ? "Yes" : "No",
chip->enable_dma ? "Yes" : "No",
chip->control & SPI_CONTROL_SSCTL ? "Yes" : "No",
chip->period & SPI_PERIOD_WAIT,
spi->mode,
spi->bits_per_word,
spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN),
spi->max_speed_hz);
return status;
err_first_setup:
kfree(chip);
return status;
}
static void cleanup(struct spi_device *spi)
{
kfree(spi_get_ctldata(spi));
}
static int __init init_queue(struct driver_data *drv_data)
{
INIT_LIST_HEAD(&drv_data->queue);
spin_lock_init(&drv_data->lock);
drv_data->run = QUEUE_STOPPED;
drv_data->busy = 0;
tasklet_init(&drv_data->pump_transfers,
pump_transfers, (unsigned long)drv_data);
INIT_WORK(&drv_data->work, pump_messages);
drv_data->workqueue = create_singlethread_workqueue(
drv_data->master->dev.parent->bus_id);
if (drv_data->workqueue == NULL)
return -EBUSY;
return 0;
}
static int start_queue(struct driver_data *drv_data)
{
unsigned long flags;
spin_lock_irqsave(&drv_data->lock, flags);
if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
spin_unlock_irqrestore(&drv_data->lock, flags);
return -EBUSY;
}
drv_data->run = QUEUE_RUNNING;
drv_data->cur_msg = NULL;
drv_data->cur_transfer = NULL;
drv_data->cur_chip = NULL;
spin_unlock_irqrestore(&drv_data->lock, flags);
queue_work(drv_data->workqueue, &drv_data->work);
return 0;
}
static int stop_queue(struct driver_data *drv_data)
{
unsigned long flags;
unsigned limit = 500;
int status = 0;
spin_lock_irqsave(&drv_data->lock, flags);
/* This is a bit lame, but is optimized for the common execution path.
* A wait_queue on the drv_data->busy could be used, but then the common
* execution path (pump_messages) would be required to call wake_up or
* friends on every SPI message. Do this instead */
drv_data->run = QUEUE_STOPPED;
while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
spin_unlock_irqrestore(&drv_data->lock, flags);
msleep(10);
spin_lock_irqsave(&drv_data->lock, flags);
}
if (!list_empty(&drv_data->queue) || drv_data->busy)
status = -EBUSY;
spin_unlock_irqrestore(&drv_data->lock, flags);
return status;
}
static int destroy_queue(struct driver_data *drv_data)
{
int status;
status = stop_queue(drv_data);
if (status != 0)
return status;
if (drv_data->workqueue)
destroy_workqueue(drv_data->workqueue);
return 0;
}
static int __init spi_imx_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct spi_imx_master *platform_info;
struct spi_master *master;
struct driver_data *drv_data;
struct resource *res;
int irq, status = 0;
platform_info = dev->platform_data;
if (platform_info == NULL) {
dev_err(&pdev->dev, "probe - no platform data supplied\n");
status = -ENODEV;
goto err_no_pdata;
}
/* Allocate master with space for drv_data */
master = spi_alloc_master(dev, sizeof(struct driver_data));
if (!master) {
dev_err(&pdev->dev, "probe - cannot alloc spi_master\n");
status = -ENOMEM;
goto err_no_mem;
}
drv_data = spi_master_get_devdata(master);
drv_data->master = master;
drv_data->master_info = platform_info;
drv_data->pdev = pdev;
master->bus_num = pdev->id;
master->num_chipselect = platform_info->num_chipselect;
master->cleanup = cleanup;
master->setup = setup;
master->transfer = transfer;
drv_data->dummy_dma_buf = SPI_DUMMY_u32;
drv_data->clk = clk_get(&pdev->dev, "perclk2");
if (IS_ERR(drv_data->clk)) {
dev_err(&pdev->dev, "probe - cannot get clock\n");
status = PTR_ERR(drv_data->clk);
goto err_no_clk;
}
clk_enable(drv_data->clk);
/* Find and map resources */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "probe - MEM resources not defined\n");
status = -ENODEV;
goto err_no_iores;
}
drv_data->ioarea = request_mem_region(res->start,
res->end - res->start + 1,
pdev->name);
if (drv_data->ioarea == NULL) {
dev_err(&pdev->dev, "probe - cannot reserve region\n");
status = -ENXIO;
goto err_no_iores;
}
drv_data->regs = ioremap(res->start, res->end - res->start + 1);
if (drv_data->regs == NULL) {
dev_err(&pdev->dev, "probe - cannot map IO\n");
status = -ENXIO;
goto err_no_iomap;
}
drv_data->rd_data_phys = (dma_addr_t)res->start;
/* Attach to IRQ */
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "probe - IRQ resource not defined\n");
status = -ENODEV;
goto err_no_irqres;
}
status = request_irq(irq, spi_int, IRQF_DISABLED, dev->bus_id, drv_data);
if (status < 0) {
dev_err(&pdev->dev, "probe - cannot get IRQ (%d)\n", status);
goto err_no_irqres;
}
/* Setup DMA if requested */
drv_data->tx_channel = -1;
drv_data->rx_channel = -1;
if (platform_info->enable_dma) {
/* Get rx DMA channel */
drv_data->rx_channel = imx_dma_request_by_prio("spi_imx_rx",
DMA_PRIO_HIGH);
if (drv_data->rx_channel < 0) {
dev_err(dev,
"probe - problem (%d) requesting rx channel\n",
drv_data->rx_channel);
goto err_no_rxdma;
} else
imx_dma_setup_handlers(drv_data->rx_channel, NULL,
dma_err_handler, drv_data);
/* Get tx DMA channel */
drv_data->tx_channel = imx_dma_request_by_prio("spi_imx_tx",
DMA_PRIO_MEDIUM);
if (drv_data->tx_channel < 0) {
dev_err(dev,
"probe - problem (%d) requesting tx channel\n",
drv_data->tx_channel);
imx_dma_free(drv_data->rx_channel);
goto err_no_txdma;
} else
imx_dma_setup_handlers(drv_data->tx_channel,
dma_tx_handler, dma_err_handler,
drv_data);
/* Set request source and burst length for allocated channels */
switch (drv_data->pdev->id) {
case 1:
/* Using SPI1 */
RSSR(drv_data->rx_channel) = DMA_REQ_SPI1_R;
RSSR(drv_data->tx_channel) = DMA_REQ_SPI1_T;
break;
case 2:
/* Using SPI2 */
RSSR(drv_data->rx_channel) = DMA_REQ_SPI2_R;
RSSR(drv_data->tx_channel) = DMA_REQ_SPI2_T;
break;
default:
dev_err(dev, "probe - bad SPI Id\n");
imx_dma_free(drv_data->rx_channel);
imx_dma_free(drv_data->tx_channel);
status = -ENODEV;
goto err_no_devid;
}
BLR(drv_data->rx_channel) = SPI_DMA_BLR;
BLR(drv_data->tx_channel) = SPI_DMA_BLR;
}
/* Load default SPI configuration */
writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
writel(0, drv_data->regs + SPI_RESET);
writel(SPI_DEFAULT_CONTROL, drv_data->regs + SPI_CONTROL);
/* Initial and start queue */
status = init_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "probe - problem initializing queue\n");
goto err_init_queue;
}
status = start_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "probe - problem starting queue\n");
goto err_start_queue;
}
/* Register with the SPI framework */
platform_set_drvdata(pdev, drv_data);
status = spi_register_master(master);
if (status != 0) {
dev_err(&pdev->dev, "probe - problem registering spi master\n");
goto err_spi_register;
}
dev_dbg(dev, "probe succeded\n");
return 0;
err_init_queue:
err_start_queue:
err_spi_register:
destroy_queue(drv_data);
err_no_rxdma:
err_no_txdma:
err_no_devid:
free_irq(irq, drv_data);
err_no_irqres:
iounmap(drv_data->regs);
err_no_iomap:
release_resource(drv_data->ioarea);
kfree(drv_data->ioarea);
err_no_iores:
clk_disable(drv_data->clk);
clk_put(drv_data->clk);
err_no_clk:
spi_master_put(master);
err_no_pdata:
err_no_mem:
return status;
}
static int __exit spi_imx_remove(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int irq;
int status = 0;
if (!drv_data)
return 0;
tasklet_kill(&drv_data->pump_transfers);
/* Remove the queue */
status = destroy_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "queue remove failed (%d)\n", status);
return status;
}
/* Reset SPI */
writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
writel(0, drv_data->regs + SPI_RESET);
/* Release DMA */
if (drv_data->master_info->enable_dma) {
RSSR(drv_data->rx_channel) = 0;
RSSR(drv_data->tx_channel) = 0;
imx_dma_free(drv_data->tx_channel);
imx_dma_free(drv_data->rx_channel);
}
/* Release IRQ */
irq = platform_get_irq(pdev, 0);
if (irq >= 0)
free_irq(irq, drv_data);
clk_disable(drv_data->clk);
clk_put(drv_data->clk);
/* Release map resources */
iounmap(drv_data->regs);
release_resource(drv_data->ioarea);
kfree(drv_data->ioarea);
/* Disconnect from the SPI framework */
spi_unregister_master(drv_data->master);
spi_master_put(drv_data->master);
/* Prevent double remove */
platform_set_drvdata(pdev, NULL);
dev_dbg(&pdev->dev, "remove succeded\n");
return 0;
}
static void spi_imx_shutdown(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
/* Reset SPI */
writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
writel(0, drv_data->regs + SPI_RESET);
dev_dbg(&pdev->dev, "shutdown succeded\n");
}
#ifdef CONFIG_PM
static int spi_imx_suspend(struct platform_device *pdev, pm_message_t state)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int status = 0;
status = stop_queue(drv_data);
if (status != 0) {
dev_warn(&pdev->dev, "suspend cannot stop queue\n");
return status;
}
dev_dbg(&pdev->dev, "suspended\n");
return 0;
}
static int spi_imx_resume(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int status = 0;
/* Start the queue running */
status = start_queue(drv_data);
if (status != 0)
dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
else
dev_dbg(&pdev->dev, "resumed\n");
return status;
}
#else
#define spi_imx_suspend NULL
#define spi_imx_resume NULL
#endif /* CONFIG_PM */
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:spi_imx");
static struct platform_driver driver = {
.driver = {
.name = "spi_imx",
.owner = THIS_MODULE,
},
.remove = __exit_p(spi_imx_remove),
.shutdown = spi_imx_shutdown,
.suspend = spi_imx_suspend,
.resume = spi_imx_resume,
};
static int __init spi_imx_init(void)
{
return platform_driver_probe(&driver, spi_imx_probe);
}
module_init(spi_imx_init);
static void __exit spi_imx_exit(void)
{
platform_driver_unregister(&driver);
}
module_exit(spi_imx_exit);
MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
MODULE_DESCRIPTION("iMX SPI Controller Driver");
MODULE_LICENSE("GPL");
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