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authorBob Liu <lliubbo@gmail.com>2011-01-11 11:19:07 -0500
committerGrant Likely <grant.likely@secretlab.ca>2011-02-15 13:56:58 -0700
commit4d676fc5c39a677aa72148debd47029d8d8f0634 (patch)
tree5f2e97edbf7870a5cdb789faffde7ebeca25648e /drivers/spi
parentb214b7bbffca8ac6a6f1dad46408f7a9d4219098 (diff)
downloadlinux-4d676fc5c39a677aa72148debd47029d8d8f0634.tar.bz2
spi/bfin_spi: support for multiples of 8bits with hardware CS
We can do multiples of 8bit transfers when using the hardware CS and a little bit of magic, so make it work. Signed-off-by: Bob Liu <lliubbo@gmail.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi_bfin5xx.c103
1 files changed, 71 insertions, 32 deletions
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 3f223511127b..e8d68b79e98f 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -425,6 +425,7 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
struct bfin_spi_slave_data *chip = drv_data->cur_chip;
struct spi_message *msg = drv_data->cur_msg;
int n_bytes = drv_data->n_bytes;
+ int loop = 0;
/* wait until transfer finished. */
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
@@ -435,10 +436,15 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
/* last read */
if (drv_data->rx) {
dev_dbg(&drv_data->pdev->dev, "last read\n");
- if (n_bytes == 2)
- *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
- else if (n_bytes == 1)
- *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
+ if (n_bytes % 2) {
+ u16 *buf = (u16 *)drv_data->rx;
+ for (loop = 0; loop < n_bytes / 2; loop++)
+ *buf++ = read_RDBR(drv_data);
+ } else {
+ u8 *buf = (u8 *)drv_data->rx;
+ for (loop = 0; loop < n_bytes; loop++)
+ *buf++ = read_RDBR(drv_data);
+ }
drv_data->rx += n_bytes;
}
@@ -458,29 +464,53 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
if (drv_data->rx && drv_data->tx) {
/* duplex */
dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n");
- if (drv_data->n_bytes == 2) {
- *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
- write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
- } else if (drv_data->n_bytes == 1) {
- *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
- write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
+ if (n_bytes % 2) {
+ u16 *buf = (u16 *)drv_data->rx;
+ u16 *buf2 = (u16 *)drv_data->tx;
+ for (loop = 0; loop < n_bytes / 2; loop++) {
+ *buf++ = read_RDBR(drv_data);
+ write_TDBR(drv_data, *buf2++);
+ }
+ } else {
+ u8 *buf = (u8 *)drv_data->rx;
+ u8 *buf2 = (u8 *)drv_data->tx;
+ for (loop = 0; loop < n_bytes; loop++) {
+ *buf++ = read_RDBR(drv_data);
+ write_TDBR(drv_data, *buf2++);
+ }
}
} else if (drv_data->rx) {
/* read */
dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n");
- if (drv_data->n_bytes == 2)
- *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
- else if (drv_data->n_bytes == 1)
- *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
- write_TDBR(drv_data, chip->idle_tx_val);
+ if (n_bytes % 2) {
+ u16 *buf = (u16 *)drv_data->rx;
+ for (loop = 0; loop < n_bytes / 2; loop++) {
+ *buf++ = read_RDBR(drv_data);
+ write_TDBR(drv_data, chip->idle_tx_val);
+ }
+ } else {
+ u8 *buf = (u8 *)drv_data->rx;
+ for (loop = 0; loop < n_bytes; loop++) {
+ *buf++ = read_RDBR(drv_data);
+ write_TDBR(drv_data, chip->idle_tx_val);
+ }
+ }
} else if (drv_data->tx) {
/* write */
dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n");
- bfin_spi_dummy_read(drv_data);
- if (drv_data->n_bytes == 2)
- write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
- else if (drv_data->n_bytes == 1)
- write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
+ if (n_bytes % 2) {
+ u16 *buf = (u16 *)drv_data->tx;
+ for (loop = 0; loop < n_bytes / 2; loop++) {
+ read_RDBR(drv_data);
+ write_TDBR(drv_data, *buf++);
+ }
+ } else {
+ u8 *buf = (u8 *)drv_data->tx;
+ for (loop = 0; loop < n_bytes; loop++) {
+ read_RDBR(drv_data);
+ write_TDBR(drv_data, *buf++);
+ }
+ }
}
if (drv_data->tx)
@@ -651,16 +681,16 @@ static void bfin_spi_pump_transfers(unsigned long data)
/* Bits per word setup */
bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word;
- if (bits_per_word == 8) {
- drv_data->n_bytes = 1;
- drv_data->len = transfer->len;
- cr_width = 0;
- drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
- } else if (bits_per_word == 16) {
- drv_data->n_bytes = 2;
+ if ((bits_per_word > 0) && (bits_per_word % 16 == 0)) {
+ drv_data->n_bytes = bits_per_word/8;
drv_data->len = (transfer->len) >> 1;
cr_width = BIT_CTL_WORDSIZE;
drv_data->ops = &bfin_bfin_spi_transfer_ops_u16;
+ } else if ((bits_per_word > 0) && (bits_per_word % 8 == 0)) {
+ drv_data->n_bytes = bits_per_word/8;
+ drv_data->len = transfer->len;
+ cr_width = 0;
+ drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
} else {
dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n");
message->status = -EINVAL;
@@ -815,10 +845,19 @@ static void bfin_spi_pump_transfers(unsigned long data)
if (drv_data->tx == NULL)
write_TDBR(drv_data, chip->idle_tx_val);
else {
- if (bits_per_word == 8)
- write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
- else
- write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
+ int loop;
+ if (bits_per_word % 16 == 0) {
+ u16 *buf = (u16 *)drv_data->tx;
+ for (loop = 0; loop < bits_per_word / 16;
+ loop++) {
+ write_TDBR(drv_data, *buf++);
+ }
+ } else if (bits_per_word % 8 == 0) {
+ u8 *buf = (u8 *)drv_data->tx;
+ for (loop = 0; loop < bits_per_word / 8; loop++)
+ write_TDBR(drv_data, *buf++);
+ }
+
drv_data->tx += drv_data->n_bytes;
}
@@ -1031,7 +1070,7 @@ static int bfin_spi_setup(struct spi_device *spi)
chip->ctl_reg &= bfin_ctl_reg;
}
- if (spi->bits_per_word != 8 && spi->bits_per_word != 16) {
+ if (spi->bits_per_word % 8) {
dev_err(&spi->dev, "%d bits_per_word is not supported\n",
spi->bits_per_word);
goto error;