spi: spi_bfin: change handling of communication parameters
Fix SPI driver to work with SPI flash ST M25P16 on bf548
Currently the SPI driver enables the SPI controller and sets the SPI baud
register for each SPI transfer. But they should never be changed within a SPI
message session, in which several SPI transfers are pumped.
This patch moves SPI setting to the begining of a message session, and
never disables SPI controller until an error occurs.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
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>
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 4496ed15..c99a2af 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -222,9 +222,13 @@
dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
/* Load the registers */
- write_CTRL(chip->ctl_reg);
+ cs_deactive(chip);
write_BAUD(chip->baud);
- cs_active(chip);
+ chip->ctl_reg &= (~BIT_CTL_TIMOD);
+ chip->ctl_reg |= (chip->width << 8);
+ write_CTRL(chip->ctl_reg);
+
+ bfin_spi_enable(drv_data);
if (ret)
dev_dbg(&drv_data->pdev->dev,
@@ -271,6 +275,7 @@
{
dev_dbg(&drv_data->pdev->dev,
"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)
@@ -293,16 +298,16 @@
write_TDBR(*(u8 *) (drv_data->tx));
while (read_STAT() & BIT_STAT_TXS)
continue;
- while (!(read_STAT() & BIT_STAT_SPIF))
- continue;
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->tx;
}
- cs_deactive(chip);
+ /* poll for SPI completion before returning */
+ while (!(read_STAT() & BIT_STAT_SPIF))
+ continue;
}
static void u8_reader(struct driver_data *drv_data)
@@ -314,6 +319,7 @@
write_TDBR(0xFFFF);
dummy_read();
+
while (drv_data->rx < drv_data->rx_end - 1) {
while (!(read_STAT() & BIT_STAT_RXS))
continue;
@@ -331,23 +337,30 @@
{
struct chip_data *chip = drv_data->cur_chip;
- while (drv_data->rx < drv_data->rx_end) {
- cs_active(chip);
+ /* clear TDBR buffer before read(else it will be shifted out) */
+ write_TDBR(0xFFFF);
- read_RDBR(); /* kick off */
- while (!(read_STAT() & BIT_STAT_RXS))
- continue;
- while (!(read_STAT() & BIT_STAT_SPIF))
- continue;
- *(u8 *) (drv_data->rx) = read_SHAW();
+ cs_active(chip);
+ dummy_read();
+
+ while (drv_data->rx < drv_data->rx_end - 1) {
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
+
+ while (!(read_STAT() & BIT_STAT_RXS))
+ continue;
+ cs_active(chip);
+ *(u8 *) (drv_data->rx) = read_RDBR();
++drv_data->rx;
}
cs_deactive(chip);
+ while (!(read_STAT() & BIT_STAT_RXS))
+ continue;
+ *(u8 *) (drv_data->rx) = read_SHAW();
+ ++drv_data->rx;
}
static void u8_duplex(struct driver_data *drv_data)
@@ -355,7 +368,7 @@
/* 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))
+ while (read_STAT() & BIT_STAT_TXS)
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
@@ -363,6 +376,10 @@
++drv_data->rx;
++drv_data->tx;
}
+
+ /* poll for SPI completion before returning */
+ while (!(read_STAT() & BIT_STAT_SPIF))
+ continue;
}
static void u8_cs_chg_duplex(struct driver_data *drv_data)
@@ -372,9 +389,8 @@
while (drv_data->rx < drv_data->rx_end) {
cs_active(chip);
-
write_TDBR(*(u8 *) (drv_data->tx));
- while (!(read_STAT() & BIT_STAT_SPIF))
+ while (read_STAT() & BIT_STAT_TXS)
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
@@ -386,7 +402,10 @@
++drv_data->rx;
++drv_data->tx;
}
- cs_deactive(chip);
+
+ /* poll for SPI completion before returning */
+ while (!(read_STAT() & BIT_STAT_SPIF))
+ continue;
}
static void u16_writer(struct driver_data *drv_data)
@@ -416,21 +435,26 @@
write_TDBR(*(u16 *) (drv_data->tx));
while ((read_STAT() & BIT_STAT_TXS))
continue;
- while (!(read_STAT() & BIT_STAT_SPIF))
- continue;
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->tx += 2;
}
- cs_deactive(chip);
+
+ /* poll for SPI completion before returning */
+ while (!(read_STAT() & BIT_STAT_SPIF))
+ continue;
}
static void u16_reader(struct driver_data *drv_data)
{
dev_dbg(&drv_data->pdev->dev,
"cr-16 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 - 2)) {
@@ -450,22 +474,30 @@
{
struct chip_data *chip = drv_data->cur_chip;
- while (drv_data->rx < drv_data->rx_end) {
- cs_active(chip);
+ /* clear TDBR buffer before read(else it will be shifted out) */
+ write_TDBR(0xFFFF);
- read_RDBR(); /* kick off */
- while (!(read_STAT() & BIT_STAT_RXS))
- continue;
- while (!(read_STAT() & BIT_STAT_SPIF))
- continue;
- *(u16 *) (drv_data->rx) = read_SHAW();
+ cs_active(chip);
+ dummy_read();
+
+ while (drv_data->rx < drv_data->rx_end) {
cs_deactive(chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
+
+ while (!(read_STAT() & BIT_STAT_RXS))
+ continue;
+ cs_active(chip);
+ *(u16 *) (drv_data->rx) = read_RDBR();
drv_data->rx += 2;
}
cs_deactive(chip);
+
+ while (!(read_STAT() & BIT_STAT_RXS))
+ continue;
+ *(u16 *) (drv_data->rx) = read_SHAW();
+ drv_data->rx += 2;
}
static void u16_duplex(struct driver_data *drv_data)
@@ -473,7 +505,7 @@
/* 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))
+ while (read_STAT() & BIT_STAT_TXS)
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
@@ -481,6 +513,10 @@
drv_data->rx += 2;
drv_data->tx += 2;
}
+
+ /* poll for SPI completion before returning */
+ while (!(read_STAT() & BIT_STAT_SPIF))
+ continue;
}
static void u16_cs_chg_duplex(struct driver_data *drv_data)
@@ -491,7 +527,7 @@
cs_active(chip);
write_TDBR(*(u16 *) (drv_data->tx));
- while (!(read_STAT() & BIT_STAT_SPIF))
+ while (read_STAT() & BIT_STAT_TXS)
continue;
while (!(read_STAT() & BIT_STAT_RXS))
continue;
@@ -503,7 +539,10 @@
drv_data->rx += 2;
drv_data->tx += 2;
}
- cs_deactive(chip);
+
+ /* poll for SPI completion before returning */
+ while (!(read_STAT() & BIT_STAT_SPIF))
+ continue;
}
/* test if ther is more transfer to be done */
@@ -587,8 +626,6 @@
while (!(read_STAT() & SPIF))
continue;
- bfin_spi_disable(drv_data);
-
msg->actual_length += drv_data->len_in_bytes;
if (drv_data->cs_change)
@@ -698,12 +735,8 @@
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_STAT(BIT_STAT_CLR);
+ cr = (read_CTRL() & (~BIT_CTL_TIMOD));
cs_active(chip);
dev_dbg(&drv_data->pdev->dev,
@@ -717,10 +750,8 @@
*/
if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
- write_STAT(BIT_STAT_CLR);
disable_dma(spi_dma_ch);
clear_dma_irqstat(spi_dma_ch);
- bfin_spi_disable(drv_data);
/* config dma channel */
dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
@@ -734,14 +765,14 @@
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) {
dev_dbg(&drv_data->pdev->dev,
"doing autobuffer DMA out.\n");
+ /* set SPI transfer mode */
+ write_CTRL(cr | CFG_SPI_DMAWRITE);
+
/* no irq in autobuffer mode */
dma_config =
(DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
@@ -749,8 +780,6 @@
set_dma_start_addr(spi_dma_ch,
(unsigned long)drv_data->tx);
enable_dma(spi_dma_ch);
- 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;
@@ -763,11 +792,11 @@
/* set transfer mode, and enable SPI */
dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
- /* disable SPI before write to TDBR */
- write_CTRL(cr & ~BIT_CTL_ENABLE);
+ /* set SPI transfer mode */
+ write_CTRL(cr | CFG_SPI_DMAREAD);
/* clear tx reg soformer data is not shifted out */
- write_TDBR(0xFF);
+ write_TDBR(0xFFFF);
set_dma_x_count(spi_dma_ch, drv_data->len);
@@ -779,14 +808,12 @@
(unsigned long)drv_data->rx);
enable_dma(spi_dma_ch);
- 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) {
dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
+ /* set SPI transfer mode */
+ write_CTRL(cr | CFG_SPI_DMAWRITE);
+
/* start dma */
dma_enable_irq(spi_dma_ch);
dma_config = (RESTART | dma_width | DI_EN);
@@ -794,28 +821,20 @@
set_dma_start_addr(spi_dma_ch,
(unsigned long)drv_data->tx);
enable_dma(spi_dma_ch);
-
- write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
- (CFG_SPI_ENABLE << 14));
-
}
} else {
/* IO mode write then read */
dev_dbg(&drv_data->pdev->dev, "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));
- cr |= CFG_SPI_WRITE | (width << 8) |
- (CFG_SPI_ENABLE << 14);
dev_dbg(&drv_data->pdev->dev,
"IO duplex: cr is 0x%x\n", cr);
- write_CTRL(cr);
+ /* set SPI transfer mode */
+ write_CTRL(cr | CFG_SPI_WRITE);
drv_data->duplex(drv_data);
@@ -823,13 +842,11 @@
tranf_success = 0;
} else if (drv_data->tx != NULL) {
/* write only half duplex */
- cr = (read_CTRL() & (~BIT_CTL_TIMOD));
- cr |= CFG_SPI_WRITE | (width << 8) |
- (CFG_SPI_ENABLE << 14);
dev_dbg(&drv_data->pdev->dev,
"IO write: cr is 0x%x\n", cr);
- write_CTRL(cr);
+ /* set SPI transfer mode */
+ write_CTRL(cr | CFG_SPI_WRITE);
drv_data->write(drv_data);
@@ -837,13 +854,11 @@
tranf_success = 0;
} else if (drv_data->rx != NULL) {
/* read only half duplex */
- cr = (read_CTRL() & (~BIT_CTL_TIMOD));
- cr |= CFG_SPI_READ | (width << 8) |
- (CFG_SPI_ENABLE << 14);
dev_dbg(&drv_data->pdev->dev,
"IO read: cr is 0x%x\n", cr);
- write_CTRL(cr);
+ /* set SPI transfer mode */
+ write_CTRL(cr | CFG_SPI_READ);
drv_data->read(drv_data);
if (drv_data->rx != drv_data->rx_end)
@@ -858,9 +873,6 @@
/* 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);
}