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linux/drivers/spi/pxa2xx_spi.c
Jeff Garzik c7bec5aba5 Various drivers' irq handlers: kill dead code, needless casts 
- Eliminate casts to/from void*

- Eliminate checks for conditions that never occur.  These typically
  fall into two classes:

	1) Checking for 'dev_id == NULL', then it is never called with
	NULL as an argument.

	2) Checking for invalid irq number, when the only caller (the
	system) guarantees the irq handler is called with the proper
	'irq' number argument.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-06 15:00:58 -04:00

1487 lines
38 KiB
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/*
* Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#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/errno.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/delay.h>
#include <asm/dma.h>
#include <asm/arch/hardware.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/pxa2xx_spi.h>
MODULE_AUTHOR("Stephen Street");
MODULE_DESCRIPTION("PXA2xx SSP SPI Contoller");
MODULE_LICENSE("GPL");
#define MAX_BUSES 3
#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK)
#define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
#define DEFINE_SSP_REG(reg, off) \
static inline u32 read_##reg(void *p) { return __raw_readl(p + (off)); } \
static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (off)); }
DEFINE_SSP_REG(SSCR0, 0x00)
DEFINE_SSP_REG(SSCR1, 0x04)
DEFINE_SSP_REG(SSSR, 0x08)
DEFINE_SSP_REG(SSITR, 0x0c)
DEFINE_SSP_REG(SSDR, 0x10)
DEFINE_SSP_REG(SSTO, 0x28)
DEFINE_SSP_REG(SSPSP, 0x2c)
#define START_STATE ((void*)0)
#define RUNNING_STATE ((void*)1)
#define DONE_STATE ((void*)2)
#define ERROR_STATE ((void*)-1)
#define QUEUE_RUNNING 0
#define QUEUE_STOPPED 1
struct driver_data {
/* Driver model hookup */
struct platform_device *pdev;
/* SPI framework hookup */
enum pxa_ssp_type ssp_type;
struct spi_master *master;
/* PXA hookup */
struct pxa2xx_spi_master *master_info;
/* DMA setup stuff */
int rx_channel;
int tx_channel;
u32 *null_dma_buf;
/* SSP register addresses */
void *ioaddr;
u32 ssdr_physical;
/* SSP masks*/
u32 dma_cr1;
u32 int_cr1;
u32 clear_sr;
u32 mask_sr;
/* Driver message queue */
struct workqueue_struct *workqueue;
struct work_struct pump_messages;
spinlock_t lock;
struct list_head queue;
int busy;
int run;
/* Message Transfer pump */
struct tasklet_struct pump_transfers;
/* Current message transfer state info */
struct spi_message* cur_msg;
struct spi_transfer* cur_transfer;
struct chip_data *cur_chip;
size_t len;
void *tx;
void *tx_end;
void *rx;
void *rx_end;
int dma_mapped;
dma_addr_t rx_dma;
dma_addr_t tx_dma;
size_t rx_map_len;
size_t tx_map_len;
u8 n_bytes;
u32 dma_width;
int cs_change;
void (*write)(struct driver_data *drv_data);
void (*read)(struct driver_data *drv_data);
irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
void (*cs_control)(u32 command);
};
struct chip_data {
u32 cr0;
u32 cr1;
u32 to;
u32 psp;
u32 timeout;
u8 n_bytes;
u32 dma_width;
u32 dma_burst_size;
u32 threshold;
u32 dma_threshold;
u8 enable_dma;
u8 bits_per_word;
u32 speed_hz;
void (*write)(struct driver_data *drv_data);
void (*read)(struct driver_data *drv_data);
void (*cs_control)(u32 command);
};
static void pump_messages(void *data);
static int flush(struct driver_data *drv_data)
{
unsigned long limit = loops_per_jiffy << 1;
void *reg = drv_data->ioaddr;
do {
while (read_SSSR(reg) & SSSR_RNE) {
read_SSDR(reg);
}
} while ((read_SSSR(reg) & SSSR_BSY) && limit--);
write_SSSR(SSSR_ROR, reg);
return limit;
}
static void restore_state(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
/* Clear status and disable clock */
write_SSSR(drv_data->clear_sr, reg);
write_SSCR0(drv_data->cur_chip->cr0 & ~SSCR0_SSE, reg);
/* Load the registers */
write_SSCR1(drv_data->cur_chip->cr1, reg);
write_SSCR0(drv_data->cur_chip->cr0, reg);
if (drv_data->ssp_type != PXA25x_SSP) {
write_SSTO(0, reg);
write_SSPSP(drv_data->cur_chip->psp, reg);
}
}
static void null_cs_control(u32 command)
{
}
static void null_writer(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
u8 n_bytes = drv_data->n_bytes;
while ((read_SSSR(reg) & SSSR_TNF)
&& (drv_data->tx < drv_data->tx_end)) {
write_SSDR(0, reg);
drv_data->tx += n_bytes;
}
}
static void null_reader(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
u8 n_bytes = drv_data->n_bytes;
while ((read_SSSR(reg) & SSSR_RNE)
&& (drv_data->rx < drv_data->rx_end)) {
read_SSDR(reg);
drv_data->rx += n_bytes;
}
}
static void u8_writer(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_TNF)
&& (drv_data->tx < drv_data->tx_end)) {
write_SSDR(*(u8 *)(drv_data->tx), reg);
++drv_data->tx;
}
}
static void u8_reader(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_RNE)
&& (drv_data->rx < drv_data->rx_end)) {
*(u8 *)(drv_data->rx) = read_SSDR(reg);
++drv_data->rx;
}
}
static void u16_writer(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_TNF)
&& (drv_data->tx < drv_data->tx_end)) {
write_SSDR(*(u16 *)(drv_data->tx), reg);
drv_data->tx += 2;
}
}
static void u16_reader(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_RNE)
&& (drv_data->rx < drv_data->rx_end)) {
*(u16 *)(drv_data->rx) = read_SSDR(reg);
drv_data->rx += 2;
}
}
static void u32_writer(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_TNF)
&& (drv_data->tx < drv_data->tx_end)) {
write_SSDR(*(u32 *)(drv_data->tx), reg);
drv_data->tx += 4;
}
}
static void u32_reader(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_RNE)
&& (drv_data->rx < drv_data->rx_end)) {
*(u32 *)(drv_data->rx) = read_SSDR(reg);
drv_data->rx += 4;
}
}
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;
} else
return DONE_STATE;
}
static int map_dma_buffers(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
struct device *dev = &msg->spi->dev;
if (!drv_data->cur_chip->enable_dma)
return 0;
if (msg->is_dma_mapped)
return drv_data->rx_dma && drv_data->tx_dma;
if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
return 0;
/* Modify setup if rx buffer is null */
if (drv_data->rx == NULL) {
*drv_data->null_dma_buf = 0;
drv_data->rx = drv_data->null_dma_buf;
drv_data->rx_map_len = 4;
} else
drv_data->rx_map_len = drv_data->len;
/* Modify setup if tx buffer is null */
if (drv_data->tx == NULL) {
*drv_data->null_dma_buf = 0;
drv_data->tx = drv_data->null_dma_buf;
drv_data->tx_map_len = 4;
} else
drv_data->tx_map_len = drv_data->len;
/* Stream map the rx buffer */
drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
drv_data->rx_map_len,
DMA_FROM_DEVICE);
if (dma_mapping_error(drv_data->rx_dma))
return 0;
/* Stream map the tx buffer */
drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
drv_data->tx_map_len,
DMA_TO_DEVICE);
if (dma_mapping_error(drv_data->tx_dma)) {
dma_unmap_single(dev, drv_data->rx_dma,
drv_data->rx_map_len, DMA_FROM_DEVICE);
return 0;
}
return 1;
}
static void unmap_dma_buffers(struct driver_data *drv_data)
{
struct device *dev;
if (!drv_data->dma_mapped)
return;
if (!drv_data->cur_msg->is_dma_mapped) {
dev = &drv_data->cur_msg->spi->dev;
dma_unmap_single(dev, drv_data->rx_dma,
drv_data->rx_map_len, DMA_FROM_DEVICE);
dma_unmap_single(dev, drv_data->tx_dma,
drv_data->tx_map_len, DMA_TO_DEVICE);
}
drv_data->dma_mapped = 0;
}
/* caller already set message->status; dma and pio irqs are blocked */
static void giveback(struct driver_data *drv_data)
{
struct spi_transfer* last_transfer;
unsigned long flags;
struct spi_message *msg;
spin_lock_irqsave(&drv_data->lock, flags);
msg = drv_data->cur_msg;
drv_data->cur_msg = NULL;
drv_data->cur_transfer = NULL;
drv_data->cur_chip = NULL;
queue_work(drv_data->workqueue, &drv_data->pump_messages);
spin_unlock_irqrestore(&drv_data->lock, flags);
last_transfer = list_entry(msg->transfers.prev,
struct spi_transfer,
transfer_list);
if (!last_transfer->cs_change)
drv_data->cs_control(PXA2XX_CS_DEASSERT);
msg->state = NULL;
if (msg->complete)
msg->complete(msg->context);
}
static int wait_ssp_rx_stall(void *ioaddr)
{
unsigned long limit = loops_per_jiffy << 1;
while ((read_SSSR(ioaddr) & SSSR_BSY) && limit--)
cpu_relax();
return limit;
}
static int wait_dma_channel_stop(int channel)
{
unsigned long limit = loops_per_jiffy << 1;
while (!(DCSR(channel) & DCSR_STOPSTATE) && limit--)
cpu_relax();
return limit;
}
static void dma_handler(int channel, void *data)
{
struct driver_data *drv_data = data;
struct spi_message *msg = drv_data->cur_msg;
void *reg = drv_data->ioaddr;
u32 irq_status = DCSR(channel) & DMA_INT_MASK;
u32 trailing_sssr = 0;
if (irq_status & DCSR_BUSERR) {
/* Disable interrupts, clear status and reset DMA */
write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, reg);
write_SSSR(drv_data->clear_sr, reg);
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
if (flush(drv_data) == 0)
dev_err(&drv_data->pdev->dev,
"dma_handler: flush fail\n");
unmap_dma_buffers(drv_data);
if (channel == drv_data->tx_channel)
dev_err(&drv_data->pdev->dev,
"dma_handler: bad bus address on "
"tx channel %d, source %x target = %x\n",
channel, DSADR(channel), DTADR(channel));
else
dev_err(&drv_data->pdev->dev,
"dma_handler: bad bus address on "
"rx channel %d, source %x target = %x\n",
channel, DSADR(channel), DTADR(channel));
msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
}
/* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
if ((drv_data->ssp_type == PXA25x_SSP)
&& (channel == drv_data->tx_channel)
&& (irq_status & DCSR_ENDINTR)) {
/* Wait for rx to stall */
if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
dev_err(&drv_data->pdev->dev,
"dma_handler: ssp rx stall failed\n");
/* Clear and disable interrupts on SSP and DMA channels*/
write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
write_SSSR(drv_data->clear_sr, reg);
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
dev_err(&drv_data->pdev->dev,
"dma_handler: dma rx channel stop failed\n");
unmap_dma_buffers(drv_data);
/* Read trailing bytes */
/* Calculate number of trailing bytes, read them */
trailing_sssr = read_SSSR(reg);
if ((trailing_sssr & 0xf008) != 0xf000) {
drv_data->rx = drv_data->rx_end -
(((trailing_sssr >> 12) & 0x0f) + 1);
drv_data->read(drv_data);
}
msg->actual_length += drv_data->len;
/* Release chip select if requested, transfer delays are
* handled in pump_transfers */
if (drv_data->cs_change)
drv_data->cs_control(PXA2XX_CS_DEASSERT);
/* Move to next transfer */
msg->state = next_transfer(drv_data);
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
}
}
static irqreturn_t dma_transfer(struct driver_data *drv_data)
{
u32 irq_status;
u32 trailing_sssr = 0;
struct spi_message *msg = drv_data->cur_msg;
void *reg = drv_data->ioaddr;
irq_status = read_SSSR(reg) & drv_data->mask_sr;
if (irq_status & SSSR_ROR) {
/* Clear and disable interrupts on SSP and DMA channels*/
write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, reg);
write_SSSR(drv_data->clear_sr, reg);
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
unmap_dma_buffers(drv_data);
if (flush(drv_data) == 0)
dev_err(&drv_data->pdev->dev,
"dma_transfer: flush fail\n");
dev_warn(&drv_data->pdev->dev, "dma_transfer: fifo overun\n");
drv_data->cur_msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
return IRQ_HANDLED;
}
/* Check for false positive timeout */
if ((irq_status & SSSR_TINT) && DCSR(drv_data->tx_channel) & DCSR_RUN) {
write_SSSR(SSSR_TINT, reg);
return IRQ_HANDLED;
}
if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
/* Clear and disable interrupts on SSP and DMA channels*/
write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, reg);
write_SSSR(drv_data->clear_sr, reg);
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
dev_err(&drv_data->pdev->dev,
"dma_transfer: dma rx channel stop failed\n");
if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
dev_err(&drv_data->pdev->dev,
"dma_transfer: ssp rx stall failed\n");
unmap_dma_buffers(drv_data);
/* Calculate number of trailing bytes, read them */
trailing_sssr = read_SSSR(reg);
if ((trailing_sssr & 0xf008) != 0xf000) {
drv_data->rx = drv_data->rx_end -
(((trailing_sssr >> 12) & 0x0f) + 1);
drv_data->read(drv_data);
}
msg->actual_length += drv_data->len;
/* Release chip select if requested, transfer delays are
* handled in pump_transfers */
if (drv_data->cs_change)
drv_data->cs_control(PXA2XX_CS_DEASSERT);
/* 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_transfer(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
void *reg = drv_data->ioaddr;
unsigned long limit = loops_per_jiffy << 1;
u32 irq_status;
u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
while ((irq_status = read_SSSR(reg) & irq_mask)) {
if (irq_status & SSSR_ROR) {
/* Clear and disable interrupts */
write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, reg);
write_SSSR(drv_data->clear_sr, reg);
if (flush(drv_data) == 0)
dev_err(&drv_data->pdev->dev,
"interrupt_transfer: flush fail\n");
/* Stop the SSP */
dev_warn(&drv_data->pdev->dev,
"interrupt_transfer: fifo overun\n");
msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
return IRQ_HANDLED;
}
/* Look for false positive timeout */
if ((irq_status & SSSR_TINT)
&& (drv_data->rx < drv_data->rx_end))
write_SSSR(SSSR_TINT, reg);
/* Pump data */
drv_data->read(drv_data);
drv_data->write(drv_data);
if (drv_data->tx == drv_data->tx_end) {
/* Disable tx interrupt */
write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg);
irq_mask = drv_data->mask_sr & ~SSSR_TFS;
/* PXA25x_SSP has no timeout, read trailing bytes */
if (drv_data->ssp_type == PXA25x_SSP) {
while ((read_SSSR(reg) & SSSR_BSY) && limit--)
drv_data->read(drv_data);
if (limit == 0)
dev_err(&drv_data->pdev->dev,
"interrupt_transfer: "
"trailing byte read failed\n");
}
}
if ((irq_status & SSSR_TINT)
|| (drv_data->rx == drv_data->rx_end)) {
/* Clear timeout */
write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, reg);
write_SSSR(drv_data->clear_sr, reg);
/* Update total byte transfered */
msg->actual_length += drv_data->len;
/* Release chip select if requested, transfer delays are
* handled in pump_transfers */
if (drv_data->cs_change)
drv_data->cs_control(PXA2XX_CS_DEASSERT);
/* Move to next transfer */
msg->state = next_transfer(drv_data);
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
}
}
/* We did something */
return IRQ_HANDLED;
}
static irqreturn_t ssp_int(int irq, void *dev_id)
{
struct driver_data *drv_data = dev_id;
void *reg = drv_data->ioaddr;
if (!drv_data->cur_msg) {
write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, reg);
write_SSSR(drv_data->clear_sr, reg);
dev_err(&drv_data->pdev->dev, "bad message state "
"in interrupt handler");
/* Never fail */
return IRQ_HANDLED;
}
return drv_data->transfer_handler(drv_data);
}
static void pump_transfers(unsigned long data)
{
struct driver_data *drv_data = (struct driver_data *)data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct chip_data *chip = NULL;
void *reg = drv_data->ioaddr;
u32 clk_div = 0;
u8 bits = 0;
u32 speed = 0;
u32 cr0;
/* Get current state information */
message = drv_data->cur_msg;
transfer = drv_data->cur_transfer;
chip = drv_data->cur_chip;
/* Handle for abort */
if (message->state == ERROR_STATE) {
message->status = -EIO;
giveback(drv_data);
return;
}
/* Handle end of message */
if (message->state == DONE_STATE) {
message->status = 0;
giveback(drv_data);
return;
}
/* Delay if requested at end of 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);
}
/* Setup the transfer state based on the type of transfer */
if (flush(drv_data) == 0) {
dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
message->status = -EIO;
giveback(drv_data);
return;
}
drv_data->n_bytes = chip->n_bytes;
drv_data->dma_width = chip->dma_width;
drv_data->cs_control = chip->cs_control;
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->write = drv_data->tx ? chip->write : null_writer;
drv_data->read = drv_data->rx ? chip->read : null_reader;
drv_data->cs_change = transfer->cs_change;
/* Change speed and bit per word on a per transfer */
if (transfer->speed_hz || transfer->bits_per_word) {
/* Disable clock */
write_SSCR0(chip->cr0 & ~SSCR0_SSE, reg);
cr0 = chip->cr0;
bits = chip->bits_per_word;
speed = chip->speed_hz;
if (transfer->speed_hz)
speed = transfer->speed_hz;
if (transfer->bits_per_word)
bits = transfer->bits_per_word;
if (reg == SSP1_VIRT)
clk_div = SSP1_SerClkDiv(speed);
else if (reg == SSP2_VIRT)
clk_div = SSP2_SerClkDiv(speed);
else if (reg == SSP3_VIRT)
clk_div = SSP3_SerClkDiv(speed);
if (bits <= 8) {
drv_data->n_bytes = 1;
drv_data->dma_width = DCMD_WIDTH1;
drv_data->read = drv_data->read != null_reader ?
u8_reader : null_reader;
drv_data->write = drv_data->write != null_writer ?
u8_writer : null_writer;
} else if (bits <= 16) {
drv_data->n_bytes = 2;
drv_data->dma_width = DCMD_WIDTH2;
drv_data->read = drv_data->read != null_reader ?
u16_reader : null_reader;
drv_data->write = drv_data->write != null_writer ?
u16_writer : null_writer;
} else if (bits <= 32) {
drv_data->n_bytes = 4;
drv_data->dma_width = DCMD_WIDTH4;
drv_data->read = drv_data->read != null_reader ?
u32_reader : null_reader;
drv_data->write = drv_data->write != null_writer ?
u32_writer : null_writer;
}
cr0 = clk_div
| SSCR0_Motorola
| SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
| SSCR0_SSE
| (bits > 16 ? SSCR0_EDSS : 0);
/* Start it back up */
write_SSCR0(cr0, reg);
}
message->state = RUNNING_STATE;
/* Try to map dma buffer and do a dma transfer if successful */
if ((drv_data->dma_mapped = map_dma_buffers(drv_data))) {
/* Ensure we have the correct interrupt handler */
drv_data->transfer_handler = dma_transfer;
/* Setup rx DMA Channel */
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
DTADR(drv_data->rx_channel) = drv_data->rx_dma;
if (drv_data->rx == drv_data->null_dma_buf)
/* No target address increment */
DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;
else
DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
| DCMD_FLOWSRC
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;
/* Setup tx DMA Channel */
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
DSADR(drv_data->tx_channel) = drv_data->tx_dma;
DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
if (drv_data->tx == drv_data->null_dma_buf)
/* No source address increment */
DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;
else
DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
| DCMD_FLOWTRG
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;
/* Enable dma end irqs on SSP to detect end of transfer */
if (drv_data->ssp_type == PXA25x_SSP)
DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
/* Fix me, need to handle cs polarity */
drv_data->cs_control(PXA2XX_CS_ASSERT);
/* Go baby, go */
write_SSSR(drv_data->clear_sr, reg);
DCSR(drv_data->rx_channel) |= DCSR_RUN;
DCSR(drv_data->tx_channel) |= DCSR_RUN;
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(chip->timeout, reg);
write_SSCR1(chip->cr1
| chip->dma_threshold
| drv_data->dma_cr1,
reg);
} else {
/* Ensure we have the correct interrupt handler */
drv_data->transfer_handler = interrupt_transfer;
/* Fix me, need to handle cs polarity */
drv_data->cs_control(PXA2XX_CS_ASSERT);
/* Go baby, go */
write_SSSR(drv_data->clear_sr, reg);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(chip->timeout, reg);
write_SSCR1(chip->cr1
| chip->threshold
| drv_data->int_cr1,
reg);
}
}
static void pump_messages(void *data)
{
struct driver_data *drv_data = data;
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);
/* 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 SSP 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);
drv_data->busy = 1;
spin_unlock_irqrestore(&drv_data->lock, flags);
}
static int transfer(struct spi_device *spi, struct spi_message *msg)
{
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
unsigned long flags;
spin_lock_irqsave(&drv_data->lock, flags);
if (drv_data->run == QUEUE_STOPPED) {
spin_unlock_irqrestore(&drv_data->lock, flags);
return -ESHUTDOWN;
}
msg->actual_length = 0;
msg->status = -EINPROGRESS;
msg->state = START_STATE;
list_add_tail(&msg->queue, &drv_data->queue);
if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
queue_work(drv_data->workqueue, &drv_data->pump_messages);
spin_unlock_irqrestore(&drv_data->lock, flags);
return 0;
}
static int setup(struct spi_device *spi)
{
struct pxa2xx_spi_chip *chip_info = NULL;
struct chip_data *chip;
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
unsigned int clk_div;
if (!spi->bits_per_word)
spi->bits_per_word = 8;
if (drv_data->ssp_type != PXA25x_SSP
&& (spi->bits_per_word < 4 || spi->bits_per_word > 32))
return -EINVAL;
else if (spi->bits_per_word < 4 || spi->bits_per_word > 16)
return -EINVAL;
/* Only alloc (or use chip_info) on first setup */
chip = spi_get_ctldata(spi);
if (chip == NULL) {
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->cs_control = null_cs_control;
chip->enable_dma = 0;
chip->timeout = SSP_TIMEOUT(1000);
chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1);
chip->dma_burst_size = drv_data->master_info->enable_dma ?
DCMD_BURST8 : 0;
chip_info = spi->controller_data;
}
/* chip_info isn't always needed */
if (chip_info) {
if (chip_info->cs_control)
chip->cs_control = chip_info->cs_control;
chip->timeout = SSP_TIMEOUT(chip_info->timeout_microsecs);
chip->threshold = SSCR1_RxTresh(chip_info->rx_threshold)
| SSCR1_TxTresh(chip_info->tx_threshold);
chip->enable_dma = chip_info->dma_burst_size != 0
&& drv_data->master_info->enable_dma;
chip->dma_threshold = 0;
if (chip->enable_dma) {
if (chip_info->dma_burst_size <= 8) {
chip->dma_threshold = SSCR1_RxTresh(8)
| SSCR1_TxTresh(8);
chip->dma_burst_size = DCMD_BURST8;
} else if (chip_info->dma_burst_size <= 16) {
chip->dma_threshold = SSCR1_RxTresh(16)
| SSCR1_TxTresh(16);
chip->dma_burst_size = DCMD_BURST16;
} else {
chip->dma_threshold = SSCR1_RxTresh(32)
| SSCR1_TxTresh(32);
chip->dma_burst_size = DCMD_BURST32;
}
}
if (chip_info->enable_loopback)
chip->cr1 = SSCR1_LBM;
}
if (drv_data->ioaddr == SSP1_VIRT)
clk_div = SSP1_SerClkDiv(spi->max_speed_hz);
else if (drv_data->ioaddr == SSP2_VIRT)
clk_div = SSP2_SerClkDiv(spi->max_speed_hz);
else if (drv_data->ioaddr == SSP3_VIRT)
clk_div = SSP3_SerClkDiv(spi->max_speed_hz);
else
return -ENODEV;
chip->speed_hz = spi->max_speed_hz;
chip->cr0 = clk_div
| SSCR0_Motorola
| SSCR0_DataSize(spi->bits_per_word > 16 ?
spi->bits_per_word - 16 : spi->bits_per_word)
| SSCR0_SSE
| (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) << 4)
| (((spi->mode & SPI_CPOL) != 0) << 3);
/* NOTE: PXA25x_SSP _could_ use external clocking ... */
if (drv_data->ssp_type != PXA25x_SSP)
dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
spi->bits_per_word,
(CLOCK_SPEED_HZ)
/ (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
spi->mode & 0x3);
else
dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
spi->bits_per_word,
(CLOCK_SPEED_HZ/2)
/ (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
spi->mode & 0x3);
if (spi->bits_per_word <= 8) {
chip->n_bytes = 1;
chip->dma_width = DCMD_WIDTH1;
chip->read = u8_reader;
chip->write = u8_writer;
} else if (spi->bits_per_word <= 16) {
chip->n_bytes = 2;
chip->dma_width = DCMD_WIDTH2;
chip->read = u16_reader;
chip->write = u16_writer;
} else if (spi->bits_per_word <= 32) {
chip->cr0 |= SSCR0_EDSS;
chip->n_bytes = 4;
chip->dma_width = DCMD_WIDTH4;
chip->read = u32_reader;
chip->write = u32_writer;
} else {
dev_err(&spi->dev, "invalid wordsize\n");
kfree(chip);
return -ENODEV;
}
chip->bits_per_word = spi->bits_per_word;
spi_set_ctldata(spi, chip);
return 0;
}
static void cleanup(const struct spi_device *spi)
{
struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
kfree(chip);
}
static int 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->pump_messages, pump_messages, drv_data);
drv_data->workqueue = create_singlethread_workqueue(
drv_data->master->cdev.dev->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->pump_messages);
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;
destroy_workqueue(drv_data->workqueue);
return 0;
}
static int pxa2xx_spi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct pxa2xx_spi_master *platform_info;
struct spi_master *master;
struct driver_data *drv_data = 0;
struct resource *memory_resource;
int irq;
int status = 0;
platform_info = dev->platform_data;
if (platform_info->ssp_type == SSP_UNDEFINED) {
dev_err(&pdev->dev, "undefined SSP\n");
return -ENODEV;
}
/* Allocate master with space for drv_data and null dma buffer */
master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
if (!master) {
dev_err(&pdev->dev, "can not alloc spi_master\n");
return -ENOMEM;
}
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->ssp_type = platform_info->ssp_type;
drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
sizeof(struct driver_data)), 8);
/* Setup register addresses */
memory_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!memory_resource) {
dev_err(&pdev->dev, "memory resources not defined\n");
status = -ENODEV;
goto out_error_master_alloc;
}
drv_data->ioaddr = (void *)io_p2v((unsigned long)(memory_resource->start));
drv_data->ssdr_physical = memory_resource->start + 0x00000010;
if (platform_info->ssp_type == PXA25x_SSP) {
drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
drv_data->dma_cr1 = 0;
drv_data->clear_sr = SSSR_ROR;
drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
} else {
drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE;
drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
}
/* Attach to IRQ */
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "irq resource not defined\n");
status = -ENODEV;
goto out_error_master_alloc;
}
status = request_irq(irq, ssp_int, 0, dev->bus_id, drv_data);
if (status < 0) {
dev_err(&pdev->dev, "can not get IRQ\n");
goto out_error_master_alloc;
}
/* Setup DMA if requested */
drv_data->tx_channel = -1;
drv_data->rx_channel = -1;
if (platform_info->enable_dma) {
/* Get two DMA channels (rx and tx) */
drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx",
DMA_PRIO_HIGH,
dma_handler,
drv_data);
if (drv_data->rx_channel < 0) {
dev_err(dev, "problem (%d) requesting rx channel\n",
drv_data->rx_channel);
status = -ENODEV;
goto out_error_irq_alloc;
}
drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx",
DMA_PRIO_MEDIUM,
dma_handler,
drv_data);
if (drv_data->tx_channel < 0) {
dev_err(dev, "problem (%d) requesting tx channel\n",
drv_data->tx_channel);
status = -ENODEV;
goto out_error_dma_alloc;
}
if (drv_data->ioaddr == SSP1_VIRT) {
DRCMRRXSSDR = DRCMR_MAPVLD
| drv_data->rx_channel;
DRCMRTXSSDR = DRCMR_MAPVLD
| drv_data->tx_channel;
} else if (drv_data->ioaddr == SSP2_VIRT) {
DRCMRRXSS2DR = DRCMR_MAPVLD
| drv_data->rx_channel;
DRCMRTXSS2DR = DRCMR_MAPVLD
| drv_data->tx_channel;
} else if (drv_data->ioaddr == SSP3_VIRT) {
DRCMRRXSS3DR = DRCMR_MAPVLD
| drv_data->rx_channel;
DRCMRTXSS3DR = DRCMR_MAPVLD
| drv_data->tx_channel;
} else {
dev_err(dev, "bad SSP type\n");
goto out_error_dma_alloc;
}
}
/* Enable SOC clock */
pxa_set_cken(platform_info->clock_enable, 1);
/* Load default SSP configuration */
write_SSCR0(0, drv_data->ioaddr);
write_SSCR1(SSCR1_RxTresh(4) | SSCR1_TxTresh(12), drv_data->ioaddr);
write_SSCR0(SSCR0_SerClkDiv(2)
| SSCR0_Motorola
| SSCR0_DataSize(8),
drv_data->ioaddr);
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, drv_data->ioaddr);
write_SSPSP(0, drv_data->ioaddr);
/* Initial and start queue */
status = init_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "problem initializing queue\n");
goto out_error_clock_enabled;
}
status = start_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "problem starting queue\n");
goto out_error_clock_enabled;
}
/* Register with the SPI framework */
platform_set_drvdata(pdev, drv_data);
status = spi_register_master(master);
if (status != 0) {
dev_err(&pdev->dev, "problem registering spi master\n");
goto out_error_queue_alloc;
}
return status;
out_error_queue_alloc:
destroy_queue(drv_data);
out_error_clock_enabled:
pxa_set_cken(platform_info->clock_enable, 0);
out_error_dma_alloc:
if (drv_data->tx_channel != -1)
pxa_free_dma(drv_data->tx_channel);
if (drv_data->rx_channel != -1)
pxa_free_dma(drv_data->rx_channel);
out_error_irq_alloc:
free_irq(irq, drv_data);
out_error_master_alloc:
spi_master_put(master);
return status;
}
static int pxa2xx_spi_remove(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int irq;
int status = 0;
if (!drv_data)
return 0;
/* Remove the queue */
status = destroy_queue(drv_data);
if (status != 0)
return status;
/* Disable the SSP at the peripheral and SOC level */
write_SSCR0(0, drv_data->ioaddr);
pxa_set_cken(drv_data->master_info->clock_enable, 0);
/* Release DMA */
if (drv_data->master_info->enable_dma) {
if (drv_data->ioaddr == SSP1_VIRT) {
DRCMRRXSSDR = 0;
DRCMRTXSSDR = 0;
} else if (drv_data->ioaddr == SSP2_VIRT) {
DRCMRRXSS2DR = 0;
DRCMRTXSS2DR = 0;
} else if (drv_data->ioaddr == SSP3_VIRT) {
DRCMRRXSS3DR = 0;
DRCMRTXSS3DR = 0;
}
pxa_free_dma(drv_data->tx_channel);
pxa_free_dma(drv_data->rx_channel);
}
/* Release IRQ */
irq = platform_get_irq(pdev, 0);
if (irq >= 0)
free_irq(irq, drv_data);
/* Disconnect from the SPI framework */
spi_unregister_master(drv_data->master);
/* Prevent double remove */
platform_set_drvdata(pdev, NULL);
return 0;
}
static void pxa2xx_spi_shutdown(struct platform_device *pdev)
{
int status = 0;
if ((status = pxa2xx_spi_remove(pdev)) != 0)
dev_err(&pdev->dev, "shutdown failed with %d\n", status);
}
#ifdef CONFIG_PM
static int suspend_devices(struct device *dev, void *pm_message)
{
pm_message_t *state = pm_message;
if (dev->power.power_state.event != state->event) {
dev_warn(dev, "pm state does not match request\n");
return -1;
}
return 0;
}
static int pxa2xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int status = 0;
/* Check all childern for current power state */
if (device_for_each_child(&pdev->dev, &state, suspend_devices) != 0) {
dev_warn(&pdev->dev, "suspend aborted\n");
return -1;
}
status = stop_queue(drv_data);
if (status != 0)
return status;
write_SSCR0(0, drv_data->ioaddr);
pxa_set_cken(drv_data->master_info->clock_enable, 0);
return 0;
}
static int pxa2xx_spi_resume(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int status = 0;
/* Enable the SSP clock */
pxa_set_cken(drv_data->master_info->clock_enable, 1);
/* Start the queue running */
status = start_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
return status;
}
return 0;
}
#else
#define pxa2xx_spi_suspend NULL
#define pxa2xx_spi_resume NULL
#endif /* CONFIG_PM */
static struct platform_driver driver = {
.driver = {
.name = "pxa2xx-spi",
.bus = &platform_bus_type,
.owner = THIS_MODULE,
},
.probe = pxa2xx_spi_probe,
.remove = __devexit_p(pxa2xx_spi_remove),
.shutdown = pxa2xx_spi_shutdown,
.suspend = pxa2xx_spi_suspend,
.resume = pxa2xx_spi_resume,
};
static int __init pxa2xx_spi_init(void)
{
platform_driver_register(&driver);
return 0;
}
module_init(pxa2xx_spi_init);
static void __exit pxa2xx_spi_exit(void)
{
platform_driver_unregister(&driver);
}
module_exit(pxa2xx_spi_exit);
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