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spi: spi_bfin handles spi_transfer.cs_change 

Respect per-transfer cs_change field (protocol tweaking support) by
adding and using cs_active/cs_deactive functions.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Bryan Wu 2007-12-04 23:45:14 -08:00 committed by Linus Torvalds
parent 5fec5b5a4e
commit fad91c8909
1 changed files with 54 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
drivers/spi/spi_bfin5xx.c
View File

@ -115,6 +115,7 @@ struct driver_data {
size_t rx_map_len;
size_t tx_map_len;
u8 n_bytes;
int cs_change;
void (*write) (struct driver_data *);
void (*read) (struct driver_data *);
void (*duplex) (struct driver_data *);
@ -179,6 +180,26 @@ static int flush(struct driver_data *drv_data)
return limit;
}
/* Chip select operation functions for cs_change flag */
static void cs_active(struct chip_data *chip)
{
u16 flag = read_FLAG();
flag |= chip->flag;
flag &= ~(chip->flag << 8);
write_FLAG(flag);
}
static void cs_deactive(struct chip_data *chip)
{
u16 flag = read_FLAG();
flag |= (chip->flag << 8);
write_FLAG(flag);
}
#define MAX_SPI0_SSEL 7
/* stop controller and re-config current chip*/
@ -198,7 +219,7 @@ static int restore_state(struct driver_data *drv_data)
/* Load the registers */
write_CTRL(chip->ctl_reg);
write_BAUD(chip->baud);
write_FLAG(chip->flag);
cs_active(chip);
if (!chip->chip_select_requested) {
int i = chip->chip_select_num;
@ -273,20 +294,20 @@ 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);
cs_active(chip);
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);
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->tx;
}
write_FLAG(0xFF00);
cs_deactive(chip);
}
@ -318,7 +339,7 @@ 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);
cs_active(chip);
read_RDBR(); /* kick off */
while (!(read_STAT() & BIT_STAT_RXS))
@ -326,13 +347,13 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
*(u8 *) (drv_data->rx) = read_SHAW();
write_FLAG(0xFF00 | chip->flag);
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->rx;
}
write_FLAG(0xFF00);
cs_deactive(chip);
}
@ -356,7 +377,7 @@ 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);
cs_active(chip);
write_TDBR(*(u8 *) (drv_data->tx));
@ -365,15 +386,14 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u8 *) (drv_data->rx) = read_RDBR();
write_FLAG(0xFF00 | chip->flag);
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->rx;
++drv_data->tx;
}
write_FLAG(0xFF00);
cs_deactive(chip);
}
static void u16_writer(struct driver_data *drv_data)
@ -398,20 +418,20 @@ 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);
cs_active(chip);
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);
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->tx += 2;
}
write_FLAG(0xFF00);
cs_deactive(chip);
}
static void u16_reader(struct driver_data *drv_data)
@ -438,7 +458,7 @@ 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);
cs_active(chip);
read_RDBR(); /* kick off */
while (!(read_STAT() & BIT_STAT_RXS))
@ -446,13 +466,13 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
while (!(read_STAT() & BIT_STAT_SPIF))
continue;
*(u16 *) (drv_data->rx) = read_SHAW();
write_FLAG(0xFF00 | chip->flag);
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->rx += 2;
}
write_FLAG(0xFF00);
cs_deactive(chip);
}
static void u16_duplex(struct driver_data *drv_data)
@ -475,7 +495,7 @@ 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);
cs_active(chip);
write_TDBR(*(u16 *) (drv_data->tx));
while (!(read_STAT() & BIT_STAT_SPIF))
@ -483,14 +503,14 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data)
while (!(read_STAT() & BIT_STAT_RXS))
continue;
*(u16 *) (drv_data->rx) = read_RDBR();
write_FLAG(0xFF00 | chip->flag);
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->rx += 2;
drv_data->tx += 2;
}
write_FLAG(0xFF00);
cs_deactive(chip);
}
/* test if ther is more transfer to be done */
@ -515,6 +535,7 @@ static void *next_transfer(struct driver_data *drv_data)
*/
static void giveback(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
struct spi_transfer *last_transfer;
unsigned long flags;
struct spi_message *msg;
@ -534,10 +555,13 @@ static void giveback(struct driver_data *drv_data)
/* disable chip select signal. And not stop spi in autobuffer mode */
if (drv_data->tx_dma != 0xFFFF) {
write_FLAG(0xFF00);
cs_deactive(chip);
bfin_spi_disable(drv_data);
}
if (!drv_data->cs_change)
cs_deactive(chip);
if (msg->complete)
msg->complete(msg->context);
}
@ -546,6 +570,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
{
struct driver_data *drv_data = (struct driver_data *)dev_id;
struct spi_message *msg = drv_data->cur_msg;
struct chip_data *chip = drv_data->cur_chip;
dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
clear_dma_irqstat(CH_SPI);
@ -573,6 +598,9 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
msg->actual_length += drv_data->len_in_bytes;
if (drv_data->cs_change)
cs_deactive(chip);
/* Move to next transfer */
msg->state = next_transfer(drv_data);
@ -659,6 +687,7 @@ static void pump_transfers(unsigned long data)
drv_data->rx_dma = transfer->rx_dma;
drv_data->tx_dma = transfer->tx_dma;
drv_data->len_in_bytes = transfer->len;
drv_data->cs_change = transfer->cs_change;
width = chip->width;
if (width == CFG_SPI_WORDSIZE16) {
@ -683,7 +712,7 @@ static void pump_transfers(unsigned long data)
} else {
write_BAUD(chip->baud);
}
write_FLAG(chip->flag);
cs_active(chip);
dev_dbg(&drv_data->pdev->dev,
"now pumping a transfer: width is %d, len is %d\n",
@ -834,6 +863,9 @@ static void pump_transfers(unsigned long data)
/* Update total byte transfered */
message->actual_length += drv_data->len;
if (drv_data->cs_change)
cs_deactive(chip);
/* Move to next transfer of this msg */
message->state = next_transfer(drv_data);
}