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linux-next/drivers/spi/pxa2xx_spi.c
Stephen Street 5daa3ba0c6 [PATCH] pxa2xx-spi update 
Fix some outstanding issues with the pxa2xx_spi driver when running on a
PXA270:

- Wrong timeout calculation in the setup function due to different
  peripheral clock rates in the PXAxxx family.

- Bad handling of SSSR_TFS interrupts in interrupt_transfer function.

- Added locking to interface between the pump_messages workqueue and the
  pump_transfers tasklet.

Much thanks to Juergen Beisert for the extensive testing on the PXA270.

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21 12:59:20 -07:00

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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 pt_regs *regs)
{
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 pt_regs *regs)
{
struct driver_data *drv_data = (struct driver_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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