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Subject[PATCH 03/10] Blackfin SPI driver: add error handing
Date
 - add error handling in SPI bus driver with selecting clients
- use proper defines to access Blackfin MMRs
- remove useless SSYNCs

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
drivers/spi/spi_bfin5xx.c | 107 +++++++++++++++++++--------------------------
1 files changed, 45 insertions(+), 62 deletions(-)
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 8041b89..2f46283 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -59,10 +59,9 @@ MODULE_LICENSE("GPL");

#define DEFINE_SPI_REG(reg, off) \
static inline u16 read_##reg(void) \
- { return *(volatile unsigned short*)(SPI0_REGBASE + off); } \
+ { return bfin_read16(SPI0_REGBASE + off); } \
static inline void write_##reg(u16 v) \
- {*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\
- SSYNC();}
+ {bfin_write16(SPI0_REGBASE + off, v); }

DEFINE_SPI_REG(CTRL, 0x00)
DEFINE_SPI_REG(FLAG, 0x04)
@@ -145,7 +144,6 @@ static void bfin_spi_enable(struct driver_data *drv_data)

cr = read_CTRL();
write_CTRL(cr | BIT_CTL_ENABLE);
- SSYNC();
}

static void bfin_spi_disable(struct driver_data *drv_data)
@@ -154,7 +152,6 @@ static void bfin_spi_disable(struct driver_data *drv_data)

cr = read_CTRL();
write_CTRL(cr & (~BIT_CTL_ENABLE));
- SSYNC();
}

/* Caculate the SPI_BAUD register value based on input HZ */
@@ -182,52 +179,44 @@ static int flush(struct driver_data *drv_data)
return limit;
}

+#define MAX_SPI0_SSEL 7
+
/* stop controller and re-config current chip*/
-static void restore_state(struct driver_data *drv_data)
+static int restore_state(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
+ int ret = 0;
+ u16 ssel[MAX_SPI0_SSEL] = {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
+ P_SPI0_SSEL4, P_SPI0_SSEL5,
+ P_SPI0_SSEL6, P_SPI0_SSEL7,};

/* Clear status and disable clock */
write_STAT(BIT_STAT_CLR);
bfin_spi_disable(drv_data);
dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");

+ /* Load the registers */
+ write_CTRL(chip->ctl_reg);
+ write_BAUD(chip->baud);
+ write_FLAG(chip->flag);
+
if (!chip->chip_select_requested) {
+ int i = chip->chip_select_num;

- dev_dbg(&drv_data->pdev->dev,
- "chip select number is %d\n", chip->chip_select_num);
-
- switch (chip->chip_select_num) {
- case 1:
- peripheral_request(P_SPI0_SSEL1, DRV_NAME);
- break;
- case 2:
- peripheral_request(P_SPI0_SSEL2, DRV_NAME);
- break;
- case 3:
- peripheral_request(P_SPI0_SSEL3, DRV_NAME);
- break;
- case 4:
- peripheral_request(P_SPI0_SSEL4, DRV_NAME);
- break;
- case 5:
- peripheral_request(P_SPI0_SSEL5, DRV_NAME);
- break;
- case 6:
- peripheral_request(P_SPI0_SSEL6, DRV_NAME);
- break;
- case 7:
- peripheral_request(P_SPI0_SSEL7, DRV_NAME);
- break;
- }
+ dev_dbg(&drv_data->pdev->dev, "chip select number is %d\n", i);
+
+ if ((i > 0) && (i <= MAX_SPI0_SSEL))
+ ret = peripheral_request(ssel[i-1], DRV_NAME);

chip->chip_select_requested = 1;
}

- /* Load the registers */
- write_CTRL(chip->ctl_reg);
- write_BAUD(chip->baud);
- write_FLAG(chip->flag);
+ if (ret)
+ dev_dbg(&drv_data->pdev->dev,
+ ": request chip select number %d failed\n",
+ chip->chip_select_num);
+
+ return ret;
}

/* used to kick off transfer in rx mode */
@@ -285,7 +274,6 @@ static void u8_cs_chg_writer(struct driver_data *drv_data)

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)
@@ -293,13 +281,13 @@ static void u8_cs_chg_writer(struct driver_data *drv_data)
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)
@@ -331,7 +319,6 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)

while (drv_data->rx < drv_data->rx_end) {
write_FLAG(chip->flag);
- SSYNC();

read_RDBR(); /* kick off */
while (!(read_STAT() & BIT_STAT_RXS))
@@ -340,13 +327,13 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
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)
@@ -370,7 +357,7 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)

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))
@@ -379,14 +366,14 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)
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)
@@ -412,7 +399,6 @@ static void u16_cs_chg_writer(struct driver_data *drv_data)

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))
@@ -420,13 +406,12 @@ static void u16_cs_chg_writer(struct driver_data *drv_data)
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)
@@ -454,7 +439,6 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)

while (drv_data->rx < drv_data->rx_end) {
write_FLAG(chip->flag);
- SSYNC();

read_RDBR(); /* kick off */
while (!(read_STAT() & BIT_STAT_RXS))
@@ -463,13 +447,12 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
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)
@@ -493,7 +476,6 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data)

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))
@@ -502,14 +484,13 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data)
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 */
@@ -811,7 +792,6 @@ static void pump_transfers(unsigned long data)
"IO duplex: cr is 0x%x\n", cr);

write_CTRL(cr);
- SSYNC();

drv_data->duplex(drv_data);

@@ -826,7 +806,6 @@ static void pump_transfers(unsigned long data)
"IO write: cr is 0x%x\n", cr);

write_CTRL(cr);
- SSYNC();

drv_data->write(drv_data);

@@ -841,7 +820,6 @@ static void pump_transfers(unsigned long data)
"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)
@@ -890,6 +868,14 @@ static void pump_messages(struct work_struct *work)
/* Extract head of queue */
drv_data->cur_msg = list_entry(drv_data->queue.next,
struct spi_message, queue);
+
+ /* Setup the SSP using the per chip configuration */
+ drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
+ if (restore_state(drv_data)) {
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return;
+ };
+
list_del_init(&drv_data->cur_msg->queue);

/* Initial message state */
@@ -897,13 +883,10 @@ static void pump_messages(struct work_struct *work)
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);
dev_dbg(&drv_data->pdev->dev,
"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);
+ drv_data->cur_chip->baud, drv_data->cur_chip->flag,
+ drv_data->cur_chip->ctl_reg);

dev_dbg(&drv_data->pdev->dev,
"the first transfer len is %d\n",
--
1.5.3.4
-
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