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linux/drivers/spi/spi_bfin5xx.c
Wu, Bryan a5f6abd4f7 Blackfin: blackfin on-chip SPI controller driver 
This patch implements the driver necessary use the Analog Devices Blackfin
processor's SPI Port.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:58 -07:00

1314 lines
32 KiB
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/*
* File: drivers/spi/bfin5xx_spi.c
* Based on: N/A
* Author: Luke Yang (Analog Devices Inc.)
*
* Created: March. 10th 2006
* Description: SPI controller driver for Blackfin 5xx
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* Modified:
* March 10, 2006 bfin5xx_spi.c Created. (Luke Yang)
* August 7, 2006 added full duplex mode (Axel Weiss & Luke Yang)
*
* Copyright 2004-2006 Analog Devices Inc.
*
* 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, 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 ; see the file COPYING.
* If not, write to the Free Software Foundation,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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/delay.h>
#include <asm/dma.h>
#include <asm/bfin5xx_spi.h>
MODULE_AUTHOR("Luke Yang");
MODULE_DESCRIPTION("Blackfin 5xx SPI Contoller");
MODULE_LICENSE("GPL");
#define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
#define DEFINE_SPI_REG(reg, off) \
static inline u16 read_##reg(void) \
{ return *(volatile unsigned short*)(SPI0_REGBASE + off); } \
static inline void write_##reg(u16 v) \
{*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\
SSYNC();}
DEFINE_SPI_REG(CTRL, 0x00)
DEFINE_SPI_REG(FLAG, 0x04)
DEFINE_SPI_REG(STAT, 0x08)
DEFINE_SPI_REG(TDBR, 0x0C)
DEFINE_SPI_REG(RDBR, 0x10)
DEFINE_SPI_REG(BAUD, 0x14)
DEFINE_SPI_REG(SHAW, 0x18)
#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
int dma_requested;
struct driver_data {
/* Driver model hookup */
struct platform_device *pdev;
/* SPI framework hookup */
struct spi_master *master;
/* BFIN hookup */
struct bfin5xx_spi_master *master_info;
/* 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_in_bytes;
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;
void (*write) (struct driver_data *);
void (*read) (struct driver_data *);
void (*duplex) (struct driver_data *);
};
struct chip_data {
u16 ctl_reg;
u16 baud;
u16 flag;
u8 chip_select_num;
u8 n_bytes;
u32 width; /* 0 or 1 */
u8 enable_dma;
u8 bits_per_word; /* 8 or 16 */
u8 cs_change_per_word;
u8 cs_chg_udelay;
void (*write) (struct driver_data *);
void (*read) (struct driver_data *);
void (*duplex) (struct driver_data *);
};
void bfin_spi_enable(struct driver_data *drv_data)
{
u16 cr;
cr = read_CTRL();
write_CTRL(cr | BIT_CTL_ENABLE);
SSYNC();
}
void bfin_spi_disable(struct driver_data *drv_data)
{
u16 cr;
cr = read_CTRL();
write_CTRL(cr & (~BIT_CTL_ENABLE));
SSYNC();
}
/* Caculate the SPI_BAUD register value based on input HZ */
static u16 hz_to_spi_baud(u32 speed_hz)
{
u_long sclk = get_sclk();
u16 spi_baud = (sclk / (2 * speed_hz));
if ((sclk % (2 * speed_hz)) > 0)
spi_baud++;
pr_debug("sclk = %ld, speed_hz = %d, spi_baud = %d\n", sclk, speed_hz,
spi_baud);
return spi_baud;
}
static int flush(struct driver_data *drv_data)
{
unsigned long limit = loops_per_jiffy << 1;
/* wait for stop and clear stat */
while (!(read_STAT() & BIT_STAT_SPIF) && limit--)
continue;
write_STAT(BIT_STAT_CLR);
return limit;
}
/* stop controller and re-config current chip*/
static void restore_state(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
/* Clear status and disable clock */
write_STAT(BIT_STAT_CLR);
bfin_spi_disable(drv_data);
pr_debug("restoring spi ctl state\n");
#if defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537)
pr_debug("chip select number is %d\n", chip->chip_select_num);
switch (chip->chip_select_num) {
case 1:
bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3c00);
SSYNC();
break;
case 2:
case 3:
bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJSE_SPI);
SSYNC();
bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
SSYNC();
break;
case 4:
bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS4E_SPI);
SSYNC();
bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3840);
SSYNC();
break;
case 5:
bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS5E_SPI);
SSYNC();
bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3820);
SSYNC();
break;
case 6:
bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS6E_SPI);
SSYNC();
bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3810);
SSYNC();
break;
case 7:
bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJCE_SPI);
SSYNC();
bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
SSYNC();
break;
}
#endif
/* Load the registers */
write_CTRL(chip->ctl_reg);
write_BAUD(chip->baud);
write_FLAG(chip->flag);
}
/* used to kick off transfer in rx mode */
static unsigned short dummy_read(void)
{
unsigned short tmp;
tmp = read_RDBR();
return tmp;
}
static void null_writer(struct driver_data *drv_data)
{
u8 n_bytes = drv_data->n_bytes;
while (drv_data->tx < drv_data->tx_end) {
write_TDBR(0);
while ((read_STAT() & BIT_STAT_TXS))
continue;
drv_data->tx += n_bytes;
}
}
static void null_reader(struct driver_data *drv_data)
{
u8 n_bytes = drv_data->n_bytes;
dummy_read();
while (drv_data->rx < drv_data->rx_end) {
while (!(read_STAT() & BIT_STAT_RXS))
continue;
dummy_read();
drv_data->rx += n_bytes;
}
}
static void u8_writer(struct driver_data *drv_data)
{
pr_debug("cr8-s is 0x%x\n", read_STAT());
while (drv_data->tx < drv_data->tx_end) {
write_TDBR(*(u8 *) (drv_data->tx));
while (read_STAT() & BIT_STAT_TXS)
continue;
++drv_data->tx;
}
/* poll for SPI completion before returning */
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
}
static void u8_cs_chg_writer(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
while (drv_data->tx < drv_data->tx_end) {
write_FLAG(chip->flag);
SSYNC();
write_TDBR(*(u8 *) (drv_data->tx));
while (read_STAT() & BIT_STAT_TXS)
continue;
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
write_FLAG(0xFF00 | chip->flag);
SSYNC();
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->tx;
}
write_FLAG(0xFF00);
SSYNC();
}
static void u8_reader(struct driver_data *drv_data)
{
pr_debug("cr-8 is 0x%x\n", read_STAT());
/* clear TDBR buffer before read(else it will be shifted out) */
write_TDBR(0xFFFF);
dummy_read();
while (drv_data->rx < drv_data->rx_end - 1) {
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u8 *) (drv_data->rx) = read_RDBR();
++drv_data->rx;
}
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u8 *) (drv_data->rx) = read_SHAW();
++drv_data->rx;
}
static void u8_cs_chg_reader(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
while (drv_data->rx < drv_data->rx_end) {
write_FLAG(chip->flag);
SSYNC();
read_RDBR(); /* kick off */
while (!(read_STAT() & BIT_STAT_RXS))
continue;
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
*(u8 *) (drv_data->rx) = read_SHAW();
write_FLAG(0xFF00 | chip->flag);
SSYNC();
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->rx;
}
write_FLAG(0xFF00);
SSYNC();
}
static void u8_duplex(struct driver_data *drv_data)
{
/* in duplex mode, clk is triggered by writing of TDBR */
while (drv_data->rx < drv_data->rx_end) {
write_TDBR(*(u8 *) (drv_data->tx));
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u8 *) (drv_data->rx) = read_RDBR();
++drv_data->rx;
++drv_data->tx;
}
}
static void u8_cs_chg_duplex(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
while (drv_data->rx < drv_data->rx_end) {
write_FLAG(chip->flag);
SSYNC();
write_TDBR(*(u8 *) (drv_data->tx));
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u8 *) (drv_data->rx) = read_RDBR();
write_FLAG(0xFF00 | chip->flag);
SSYNC();
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->rx;
++drv_data->tx;
}
write_FLAG(0xFF00);
SSYNC();
}
static void u16_writer(struct driver_data *drv_data)
{
pr_debug("cr16 is 0x%x\n", read_STAT());
while (drv_data->tx < drv_data->tx_end) {
write_TDBR(*(u16 *) (drv_data->tx));
while ((read_STAT() & BIT_STAT_TXS))
continue;
drv_data->tx += 2;
}
/* poll for SPI completion before returning */
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
}
static void u16_cs_chg_writer(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
while (drv_data->tx < drv_data->tx_end) {
write_FLAG(chip->flag);
SSYNC();
write_TDBR(*(u16 *) (drv_data->tx));
while ((read_STAT() & BIT_STAT_TXS))
continue;
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
write_FLAG(0xFF00 | chip->flag);
SSYNC();
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->tx += 2;
}
write_FLAG(0xFF00);
SSYNC();
}
static void u16_reader(struct driver_data *drv_data)
{
pr_debug("cr-16 is 0x%x\n", read_STAT());
dummy_read();
while (drv_data->rx < (drv_data->rx_end - 2)) {
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u16 *) (drv_data->rx) = read_RDBR();
drv_data->rx += 2;
}
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u16 *) (drv_data->rx) = read_SHAW();
drv_data->rx += 2;
}
static void u16_cs_chg_reader(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
while (drv_data->rx < drv_data->rx_end) {
write_FLAG(chip->flag);
SSYNC();
read_RDBR(); /* kick off */
while (!(read_STAT() & BIT_STAT_RXS))
continue;
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
*(u16 *) (drv_data->rx) = read_SHAW();
write_FLAG(0xFF00 | chip->flag);
SSYNC();
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->rx += 2;
}
write_FLAG(0xFF00);
SSYNC();
}
static void u16_duplex(struct driver_data *drv_data)
{
/* in duplex mode, clk is triggered by writing of TDBR */
while (drv_data->tx < drv_data->tx_end) {
write_TDBR(*(u16 *) (drv_data->tx));
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u16 *) (drv_data->rx) = read_RDBR();
drv_data->rx += 2;
drv_data->tx += 2;
}
}
static void u16_cs_chg_duplex(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
while (drv_data->tx < drv_data->tx_end) {
write_FLAG(chip->flag);
SSYNC();
write_TDBR(*(u16 *) (drv_data->tx));
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u16 *) (drv_data->rx) = read_RDBR();
write_FLAG(0xFF00 | chip->flag);
SSYNC();
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->rx += 2;
drv_data->tx += 2;
}
write_FLAG(0xFF00);
SSYNC();
}
/* test if ther is more transfer to be done */
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;
}
/*
* caller already set message->status;
* dma and pio irqs are blocked give finished message back
*/
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);
msg->state = NULL;
/* disable chip select signal. And not stop spi in autobuffer mode */
if (drv_data->tx_dma != 0xFFFF) {
write_FLAG(0xFF00);
bfin_spi_disable(drv_data);
}
if (msg->complete)
msg->complete(msg->context);
}
static irqreturn_t dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
{
struct driver_data *drv_data = (struct driver_data *)dev_id;
struct spi_message *msg = drv_data->cur_msg;
pr_debug("in dma_irq_handler\n");
clear_dma_irqstat(CH_SPI);
/*
* wait for the last transaction shifted out. yes, these two
* while loops are supposed to be the same (see the HRM).
*/
if (drv_data->tx != NULL) {
while (bfin_read_SPI_STAT() & TXS)
continue;
while (bfin_read_SPI_STAT() & TXS)
continue;
}
while (!(bfin_read_SPI_STAT() & SPIF))
continue;
bfin_spi_disable(drv_data);
msg->actual_length += drv_data->len_in_bytes;
/* Move to next transfer */
msg->state = next_transfer(drv_data);
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
/* free the irq handler before next transfer */
pr_debug("disable dma channel irq%d\n", CH_SPI);
dma_disable_irq(CH_SPI);
return IRQ_HANDLED;
}
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;
u16 cr, width, dma_width, dma_config;
u32 tranf_success = 1;
/* Get current state information */
message = drv_data->cur_msg;
transfer = drv_data->cur_transfer;
chip = drv_data->cur_chip;
/*
* if msg is error or done, report it back using complete() callback
*/
/* 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;
}
if (transfer->tx_buf != NULL) {
drv_data->tx = (void *)transfer->tx_buf;
drv_data->tx_end = drv_data->tx + transfer->len;
pr_debug("tx_buf is %p, tx_end is %p\n", transfer->tx_buf,
drv_data->tx_end);
} else {
drv_data->tx = NULL;
}
if (transfer->rx_buf != NULL) {
drv_data->rx = transfer->rx_buf;
drv_data->rx_end = drv_data->rx + transfer->len;
pr_debug("rx_buf is %p, rx_end is %p\n", transfer->rx_buf,
drv_data->rx_end);
} else {
drv_data->rx = NULL;
}
drv_data->rx_dma = transfer->rx_dma;
drv_data->tx_dma = transfer->tx_dma;
drv_data->len_in_bytes = transfer->len;
width = chip->width;
if (width == CFG_SPI_WORDSIZE16) {
drv_data->len = (transfer->len) >> 1;
} else {
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->duplex = chip->duplex ? chip->duplex : null_writer;
pr_debug
("transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
drv_data->write, chip->write, null_writer);
/* speed and width has been set on per message */
message->state = RUNNING_STATE;
dma_config = 0;
/* restore spi status for each spi transfer */
if (transfer->speed_hz) {
write_BAUD(hz_to_spi_baud(transfer->speed_hz));
} else {
write_BAUD(chip->baud);
}
write_FLAG(chip->flag);
pr_debug("now pumping a transfer: width is %d, len is %d\n", width,
transfer->len);
/*
* Try to map dma buffer and do a dma transfer if
* successful use different way to r/w according to
* drv_data->cur_chip->enable_dma
*/
if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
write_STAT(BIT_STAT_CLR);
disable_dma(CH_SPI);
clear_dma_irqstat(CH_SPI);
bfin_spi_disable(drv_data);
/* config dma channel */
pr_debug("doing dma transfer\n");
if (width == CFG_SPI_WORDSIZE16) {
set_dma_x_count(CH_SPI, drv_data->len);
set_dma_x_modify(CH_SPI, 2);
dma_width = WDSIZE_16;
} else {
set_dma_x_count(CH_SPI, drv_data->len);
set_dma_x_modify(CH_SPI, 1);
dma_width = WDSIZE_8;
}
/* set transfer width,direction. And enable spi */
cr = (read_CTRL() & (~BIT_CTL_TIMOD));
/* dirty hack for autobuffer DMA mode */
if (drv_data->tx_dma == 0xFFFF) {
pr_debug("doing autobuffer DMA out.\n");
/* no irq in autobuffer mode */
dma_config =
(DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
set_dma_config(CH_SPI, dma_config);
set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
enable_dma(CH_SPI);
write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
(CFG_SPI_ENABLE << 14));
/* just return here, there can only be one transfer in this mode */
message->status = 0;
giveback(drv_data);
return;
}
/* In dma mode, rx or tx must be NULL in one transfer */
if (drv_data->rx != NULL) {
/* set transfer mode, and enable SPI */
pr_debug("doing DMA in.\n");
/* disable SPI before write to TDBR */
write_CTRL(cr & ~BIT_CTL_ENABLE);
/* clear tx reg soformer data is not shifted out */
write_TDBR(0xFF);
set_dma_x_count(CH_SPI, drv_data->len);
/* start dma */
dma_enable_irq(CH_SPI);
dma_config = (WNR | RESTART | dma_width | DI_EN);
set_dma_config(CH_SPI, dma_config);
set_dma_start_addr(CH_SPI, (unsigned long)drv_data->rx);
enable_dma(CH_SPI);
cr |=
CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE <<
14);
/* set transfer mode, and enable SPI */
write_CTRL(cr);
} else if (drv_data->tx != NULL) {
pr_debug("doing DMA out.\n");
/* start dma */
dma_enable_irq(CH_SPI);
dma_config = (RESTART | dma_width | DI_EN);
set_dma_config(CH_SPI, dma_config);
set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
enable_dma(CH_SPI);
write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
(CFG_SPI_ENABLE << 14));
}
} else {
/* IO mode write then read */
pr_debug("doing IO transfer\n");
write_STAT(BIT_STAT_CLR);
if (drv_data->tx != NULL && drv_data->rx != NULL) {
/* full duplex mode */
BUG_ON((drv_data->tx_end - drv_data->tx) !=
(drv_data->rx_end - drv_data->rx));
cr = (read_CTRL() & (~BIT_CTL_TIMOD)); /* clear the TIMOD bits */
cr |=
CFG_SPI_WRITE | (width << 8) | (CFG_SPI_ENABLE <<
14);
pr_debug("IO duplex: cr is 0x%x\n", cr);
write_CTRL(cr);
SSYNC();
drv_data->duplex(drv_data);
if (drv_data->tx != drv_data->tx_end)
tranf_success = 0;
} else if (drv_data->tx != NULL) {
/* write only half duplex */
cr = (read_CTRL() & (~BIT_CTL_TIMOD)); /* clear the TIMOD bits */
cr |=
CFG_SPI_WRITE | (width << 8) | (CFG_SPI_ENABLE <<
14);
pr_debug("IO write: cr is 0x%x\n", cr);
write_CTRL(cr);
SSYNC();
drv_data->write(drv_data);
if (drv_data->tx != drv_data->tx_end)
tranf_success = 0;
} else if (drv_data->rx != NULL) {
/* read only half duplex */
cr = (read_CTRL() & (~BIT_CTL_TIMOD)); /* cleare the TIMOD bits */
cr |=
CFG_SPI_READ | (width << 8) | (CFG_SPI_ENABLE <<
14);
pr_debug("IO read: cr is 0x%x\n", cr);
write_CTRL(cr);
SSYNC();
drv_data->read(drv_data);
if (drv_data->rx != drv_data->rx_end)
tranf_success = 0;
}
if (!tranf_success) {
pr_debug("IO write error!\n");
message->state = ERROR_STATE;
} else {
/* Update total byte transfered */
message->actual_length += drv_data->len;
/* Move to next transfer of this msg */
message->state = next_transfer(drv_data);
}
/* Schedule next transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
}
}
/* pop a msg from queue and kick off real transfer */
static void pump_messages(struct work_struct *work)
{
struct driver_data *drv_data = container_of(work, struct driver_data, pump_messages);
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) {
/* pumper kicked off but no work to do */
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);
pr_debug
("got a message to pump, state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
drv_data->cur_chip->baud, drv_data->cur_chip->flag,
drv_data->cur_chip->ctl_reg);
pr_debug("the first transfer len is %d\n", drv_data->cur_transfer->len);
/* Mark as busy and launch transfers */
tasklet_schedule(&drv_data->pump_transfers);
drv_data->busy = 1;
spin_unlock_irqrestore(&drv_data->lock, flags);
}
/*
* got a msg to transfer, queue it in drv_data->queue.
* And kick off message pumper
*/
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;
pr_debug("adding an msg in transfer() \n");
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;
}
/* first setup for new devices */
static int setup(struct spi_device *spi)
{
struct bfin5xx_spi_chip *chip_info = NULL;
struct chip_data *chip;
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
u8 spi_flg;
/* Abort device setup if requested features are not supported */
if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
dev_err(&spi->dev, "requested mode not fully supported\n");
return -EINVAL;
}
/* Zero (the default) here means 8 bits */
if (!spi->bits_per_word)
spi->bits_per_word = 8;
if (spi->bits_per_word != 8 && 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->enable_dma = 0;
chip_info = spi->controller_data;
}
/* chip_info isn't always needed */
if (chip_info) {
chip->enable_dma = chip_info->enable_dma != 0
&& drv_data->master_info->enable_dma;
chip->ctl_reg = chip_info->ctl_reg;
chip->bits_per_word = chip_info->bits_per_word;
chip->cs_change_per_word = chip_info->cs_change_per_word;
chip->cs_chg_udelay = chip_info->cs_chg_udelay;
}
/* translate common spi framework into our register */
if (spi->mode & SPI_CPOL)
chip->ctl_reg |= CPOL;
if (spi->mode & SPI_CPHA)
chip->ctl_reg |= CPHA;
if (spi->mode & SPI_LSB_FIRST)
chip->ctl_reg |= LSBF;
/* we dont support running in slave mode (yet?) */
chip->ctl_reg |= MSTR;
/*
* if any one SPI chip is registered and wants DMA, request the
* DMA channel for it
*/
if (chip->enable_dma && !dma_requested) {
/* register dma irq handler */
if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) {
pr_debug
("Unable to request BlackFin SPI DMA channel\n");
return -ENODEV;
}
if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data)
< 0) {
pr_debug("Unable to set dma callback\n");
return -EPERM;
}
dma_disable_irq(CH_SPI);
dma_requested = 1;
}
/*
* Notice: for blackfin, the speed_hz is the value of register
* SPI_BAUD, not the real baudrate
*/
chip->baud = hz_to_spi_baud(spi->max_speed_hz);
spi_flg = ~(1 << (spi->chip_select));
chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
chip->chip_select_num = spi->chip_select;
switch (chip->bits_per_word) {
case 8:
chip->n_bytes = 1;
chip->width = CFG_SPI_WORDSIZE8;
chip->read = chip->cs_change_per_word ?
u8_cs_chg_reader : u8_reader;
chip->write = chip->cs_change_per_word ?
u8_cs_chg_writer : u8_writer;
chip->duplex = chip->cs_change_per_word ?
u8_cs_chg_duplex : u8_duplex;
break;
case 16:
chip->n_bytes = 2;
chip->width = CFG_SPI_WORDSIZE16;
chip->read = chip->cs_change_per_word ?
u16_cs_chg_reader : u16_reader;
chip->write = chip->cs_change_per_word ?
u16_cs_chg_writer : u16_writer;
chip->duplex = chip->cs_change_per_word ?
u16_cs_chg_duplex : u16_duplex;
break;
default:
dev_err(&spi->dev, "%d bits_per_word is not supported\n",
chip->bits_per_word);
kfree(chip);
return -ENODEV;
}
pr_debug("setup spi chip %s, width is %d, dma is %d,",
spi->modalias, chip->width, chip->enable_dma);
pr_debug("ctl_reg is 0x%x, flag_reg is 0x%x\n",
chip->ctl_reg, chip->flag);
spi_set_ctldata(spi, chip);
return 0;
}
/*
* callback for spi framework.
* clean driver specific data
*/
static void cleanup(const struct spi_device *spi)
{
struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
kfree(chip);
}
static inline 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;
/* init transfer tasklet */
tasklet_init(&drv_data->pump_transfers,
pump_transfers, (unsigned long)drv_data);
/* init messages workqueue */
INIT_WORK(&drv_data->pump_messages, pump_messages);
drv_data->workqueue =
create_singlethread_workqueue(drv_data->master->cdev.dev->bus_id);
if (drv_data->workqueue == NULL)
return -EBUSY;
return 0;
}
static inline 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 inline 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 inline 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 __init bfin5xx_spi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct bfin5xx_spi_master *platform_info;
struct spi_master *master;
struct driver_data *drv_data = 0;
int status = 0;
platform_info = dev->platform_data;
/* Allocate master with space for drv_data */
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;
/* Initial and start queue */
status = init_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "problem initializing queue\n");
goto out_error_queue_alloc;
}
status = start_queue(drv_data);
if (status != 0) {
dev_err(&pdev->dev, "problem starting queue\n");
goto out_error_queue_alloc;
}
/* 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;
}
pr_debug("controller probe successfully\n");
return status;
out_error_queue_alloc:
destroy_queue(drv_data);
spi_master_put(master);
return status;
}
/* stop hardware and remove the driver */
static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
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 */
bfin_spi_disable(drv_data);
/* Release DMA */
if (drv_data->master_info->enable_dma) {
if (dma_channel_active(CH_SPI))
free_dma(CH_SPI);
}
/* Disconnect from the SPI framework */
spi_unregister_master(drv_data->master);
/* Prevent double remove */
platform_set_drvdata(pdev, NULL);
return 0;
}
#ifdef CONFIG_PM
static int bfin5xx_spi_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)
return status;
/* stop hardware */
bfin_spi_disable(drv_data);
return 0;
}
static int bfin5xx_spi_resume(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
int status = 0;
/* Enable the SPI interface */
bfin_spi_enable(drv_data);
/* 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 bfin5xx_spi_suspend NULL
#define bfin5xx_spi_resume NULL
#endif /* CONFIG_PM */
static struct platform_driver bfin5xx_spi_driver = {
.driver = {
.name = "bfin-spi-master",
.bus = &platform_bus_type,
.owner = THIS_MODULE,
},
.probe = bfin5xx_spi_probe,
.remove = __devexit_p(bfin5xx_spi_remove),
.suspend = bfin5xx_spi_suspend,
.resume = bfin5xx_spi_resume,
};
static int __init bfin5xx_spi_init(void)
{
return platform_driver_register(&bfin5xx_spi_driver);
}
module_init(bfin5xx_spi_init);
static void __exit bfin5xx_spi_exit(void)
{
platform_driver_unregister(&bfin5xx_spi_driver);
}
module_exit(bfin5xx_spi_exit);
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