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authorFeng Tang <feng.tang@intel.com>2011-03-30 23:09:52 +0800
committerGrant Likely <grant.likely@secretlab.ca>2011-03-30 21:31:48 -0600
commitde6efe0a966cf86b3c4039a610b2d4157db707f2 (patch)
tree1eae388ca7196ea94d5480174d5f69fd1b43d588 /drivers/spi
parent0ce790e7d736cedc563e1fb4e998babf5a4dbc3d (diff)
spi/dw_spi: unify the low level read/write routines
The original version has many duplicated codes for null/u8/u16 case, so unify them to make it cleaner Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/dw_spi.c103
-rw-r--r--drivers/spi/dw_spi.h2
2 files changed, 26 insertions, 79 deletions
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 9a6196461b2..c4fca3d9d45 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -58,8 +58,6 @@ struct chip_data {
u8 bits_per_word;
u16 clk_div; /* baud rate divider */
u32 speed_hz; /* baud rate */
- int (*write)(struct dw_spi *dws);
- int (*read)(struct dw_spi *dws);
void (*cs_control)(u32 command);
};
@@ -185,80 +183,45 @@ static void flush(struct dw_spi *dws)
wait_till_not_busy(dws);
}
-static int null_writer(struct dw_spi *dws)
-{
- u8 n_bytes = dws->n_bytes;
-
- if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
- || (dws->tx == dws->tx_end))
- return 0;
- dw_writew(dws, dr, 0);
- dws->tx += n_bytes;
- wait_till_not_busy(dws);
- return 1;
-}
-
-static int null_reader(struct dw_spi *dws)
+static int dw_writer(struct dw_spi *dws)
{
- u8 n_bytes = dws->n_bytes;
+ u16 txw = 0;
- while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
- && (dws->rx < dws->rx_end)) {
- dw_readw(dws, dr);
- dws->rx += n_bytes;
- }
- wait_till_not_busy(dws);
- return dws->rx == dws->rx_end;
-}
-
-static int u8_writer(struct dw_spi *dws)
-{
if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
|| (dws->tx == dws->tx_end))
return 0;
- dw_writew(dws, dr, *(u8 *)(dws->tx));
- ++dws->tx;
-
- wait_till_not_busy(dws);
- return 1;
-}
-
-static int u8_reader(struct dw_spi *dws)
-{
- while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
- && (dws->rx < dws->rx_end)) {
- *(u8 *)(dws->rx) = dw_readw(dws, dr);
- ++dws->rx;
+ /* Set the tx word if the transfer's original "tx" is not null */
+ if (dws->tx_end - dws->len) {
+ if (dws->n_bytes == 1)
+ txw = *(u8 *)(dws->tx);
+ else
+ txw = *(u16 *)(dws->tx);
}
- wait_till_not_busy(dws);
- return dws->rx == dws->rx_end;
-}
-
-static int u16_writer(struct dw_spi *dws)
-{
- if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
- || (dws->tx == dws->tx_end))
- return 0;
-
- dw_writew(dws, dr, *(u16 *)(dws->tx));
- dws->tx += 2;
+ dw_writew(dws, dr, txw);
+ dws->tx += dws->n_bytes;
wait_till_not_busy(dws);
return 1;
}
-static int u16_reader(struct dw_spi *dws)
+static int dw_reader(struct dw_spi *dws)
{
- u16 temp;
+ u16 rxw;
while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
&& (dws->rx < dws->rx_end)) {
- temp = dw_readw(dws, dr);
- *(u16 *)(dws->rx) = temp;
- dws->rx += 2;
+ rxw = dw_readw(dws, dr);
+ /* Care rx only if the transfer's original "rx" is not null */
+ if (dws->rx_end - dws->len) {
+ if (dws->n_bytes == 1)
+ *(u8 *)(dws->rx) = rxw;
+ else
+ *(u16 *)(dws->rx) = rxw;
+ }
+ dws->rx += dws->n_bytes;
}
wait_till_not_busy(dws);
@@ -383,8 +346,8 @@ static irqreturn_t interrupt_transfer(struct dw_spi *dws)
left = (left > int_level) ? int_level : left;
while (left--)
- dws->write(dws);
- dws->read(dws);
+ dw_writer(dws);
+ dw_reader(dws);
/* Re-enable the IRQ if there is still data left to tx */
if (dws->tx_end > dws->tx)
@@ -417,13 +380,13 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
/* Must be called inside pump_transfers() */
static void poll_transfer(struct dw_spi *dws)
{
- while (dws->write(dws))
- dws->read(dws);
+ while (dw_writer(dws))
+ dw_reader(dws);
/*
* There is a possibility that the last word of a transaction
* will be lost if data is not ready. Re-read to solve this issue.
*/
- dws->read(dws);
+ dw_reader(dws);
dw_spi_xfer_done(dws);
}
@@ -483,8 +446,6 @@ static void pump_transfers(unsigned long data)
dws->tx_end = dws->tx + transfer->len;
dws->rx = transfer->rx_buf;
dws->rx_end = dws->rx + transfer->len;
- dws->write = dws->tx ? chip->write : null_writer;
- dws->read = dws->rx ? chip->read : null_reader;
dws->cs_change = transfer->cs_change;
dws->len = dws->cur_transfer->len;
if (chip != dws->prev_chip)
@@ -520,18 +481,10 @@ static void pump_transfers(unsigned long data)
case 8:
dws->n_bytes = 1;
dws->dma_width = 1;
- dws->read = (dws->read != null_reader) ?
- u8_reader : null_reader;
- dws->write = (dws->write != null_writer) ?
- u8_writer : null_writer;
break;
case 16:
dws->n_bytes = 2;
dws->dma_width = 2;
- dws->read = (dws->read != null_reader) ?
- u16_reader : null_reader;
- dws->write = (dws->write != null_writer) ?
- u16_writer : null_writer;
break;
default:
printk(KERN_ERR "MRST SPI0: unsupported bits:"
@@ -733,13 +686,9 @@ static int dw_spi_setup(struct spi_device *spi)
if (spi->bits_per_word <= 8) {
chip->n_bytes = 1;
chip->dma_width = 1;
- chip->read = u8_reader;
- chip->write = u8_writer;
} else if (spi->bits_per_word <= 16) {
chip->n_bytes = 2;
chip->dma_width = 2;
- chip->read = u16_reader;
- chip->write = u16_writer;
} else {
/* Never take >16b case for MRST SPIC */
dev_err(&spi->dev, "invalid wordsize\n");
diff --git a/drivers/spi/dw_spi.h b/drivers/spi/dw_spi.h
index fb0bce56484..d8aac1f4c54 100644
--- a/drivers/spi/dw_spi.h
+++ b/drivers/spi/dw_spi.h
@@ -137,8 +137,6 @@ struct dw_spi {
u8 max_bits_per_word; /* maxim is 16b */
u32 dma_width;
int cs_change;
- int (*write)(struct dw_spi *dws);
- int (*read)(struct dw_spi *dws);
irqreturn_t (*transfer_handler)(struct dw_spi *dws);
void (*cs_control)(u32 command);