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[PATCH] spi: Update to PXA2xx SPI Driver
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Fix two outstanding issues with the pxa2xx_spi driver:

1) Bad cast in the function u32_writer. Thanks to Henrik Bechmann
2) Adds support for per transfer changes to speed and bits per word

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Stephen Street authored and Greg Kroah-Hartman committed May 16, 2006
1 parent a020ed7 commit 9708c12
Showing 1 changed file with 75 additions and 7 deletions.
82 changes: 75 additions & 7 deletions drivers/spi/pxa2xx_spi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -120,6 +120,8 @@ struct driver_data {
dma_addr_t tx_dma;
size_t rx_map_len;
size_t tx_map_len;
u8 n_bytes;
u32 dma_width;
int cs_change;
void (*write)(struct driver_data *drv_data);
void (*read)(struct driver_data *drv_data);
Expand All @@ -139,6 +141,8 @@ struct chip_data {
u32 threshold;
u32 dma_threshold;
u8 enable_dma;
u8 bits_per_word;
u32 speed_hz;
void (*write)(struct driver_data *drv_data);
void (*read)(struct driver_data *drv_data);
void (*cs_control)(u32 command);
Expand Down Expand Up @@ -186,7 +190,7 @@ static void null_cs_control(u32 command)
static void null_writer(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
u8 n_bytes = drv_data->cur_chip->n_bytes;
u8 n_bytes = drv_data->n_bytes;

while ((read_SSSR(reg) & SSSR_TNF)
&& (drv_data->tx < drv_data->tx_end)) {
Expand All @@ -198,7 +202,7 @@ static void null_writer(struct driver_data *drv_data)
static void null_reader(struct driver_data *drv_data)
{
void *reg = drv_data->ioaddr;
u8 n_bytes = drv_data->cur_chip->n_bytes;
u8 n_bytes = drv_data->n_bytes;

while ((read_SSSR(reg) & SSSR_RNE)
&& (drv_data->rx < drv_data->rx_end)) {
Expand Down Expand Up @@ -256,7 +260,7 @@ static void u32_writer(struct driver_data *drv_data)

while ((read_SSSR(reg) & SSSR_TNF)
&& (drv_data->tx < drv_data->tx_end)) {
write_SSDR(*(u16 *)(drv_data->tx), reg);
write_SSDR(*(u32 *)(drv_data->tx), reg);
drv_data->tx += 4;
}
}
Expand Down Expand Up @@ -677,6 +681,10 @@ static void pump_transfers(unsigned long data)
struct spi_transfer *previous = NULL;
struct chip_data *chip = NULL;
void *reg = drv_data->ioaddr;
u32 clk_div = 0;
u8 bits = 0;
u32 speed = 0;
u32 cr0;

/* Get current state information */
message = drv_data->cur_msg;
Expand Down Expand Up @@ -713,6 +721,8 @@ static void pump_transfers(unsigned long data)
giveback(message, drv_data);
return;
}
drv_data->n_bytes = chip->n_bytes;
drv_data->dma_width = chip->dma_width;
drv_data->cs_control = chip->cs_control;
drv_data->tx = (void *)transfer->tx_buf;
drv_data->tx_end = drv_data->tx + transfer->len;
Expand All @@ -724,6 +734,62 @@ static void pump_transfers(unsigned long data)
drv_data->write = drv_data->tx ? chip->write : null_writer;
drv_data->read = drv_data->rx ? chip->read : null_reader;
drv_data->cs_change = transfer->cs_change;

/* Change speed and bit per word on a per transfer */
if (transfer->speed_hz || transfer->bits_per_word) {

/* Disable clock */
write_SSCR0(chip->cr0 & ~SSCR0_SSE, reg);
cr0 = chip->cr0;
bits = chip->bits_per_word;
speed = chip->speed_hz;

if (transfer->speed_hz)
speed = transfer->speed_hz;

if (transfer->bits_per_word)
bits = transfer->bits_per_word;

if (reg == SSP1_VIRT)
clk_div = SSP1_SerClkDiv(speed);
else if (reg == SSP2_VIRT)
clk_div = SSP2_SerClkDiv(speed);
else if (reg == SSP3_VIRT)
clk_div = SSP3_SerClkDiv(speed);

if (bits <= 8) {
drv_data->n_bytes = 1;
drv_data->dma_width = DCMD_WIDTH1;
drv_data->read = drv_data->read != null_reader ?
u8_reader : null_reader;
drv_data->write = drv_data->write != null_writer ?
u8_writer : null_writer;
} else if (bits <= 16) {
drv_data->n_bytes = 2;
drv_data->dma_width = DCMD_WIDTH2;
drv_data->read = drv_data->read != null_reader ?
u16_reader : null_reader;
drv_data->write = drv_data->write != null_writer ?
u16_writer : null_writer;
} else if (bits <= 32) {
drv_data->n_bytes = 4;
drv_data->dma_width = DCMD_WIDTH4;
drv_data->read = drv_data->read != null_reader ?
u32_reader : null_reader;
drv_data->write = drv_data->write != null_writer ?
u32_writer : null_writer;
}

cr0 = clk_div
| SSCR0_Motorola
| SSCR0_DataSize(bits & 0x0f)
| SSCR0_SSE
| (bits > 16 ? SSCR0_EDSS : 0);

/* Start it back up */
write_SSCR0(cr0, reg);
}

message->state = RUNNING_STATE;

/* Try to map dma buffer and do a dma transfer if successful */
Expand All @@ -739,13 +805,13 @@ static void pump_transfers(unsigned long data)
if (drv_data->rx == drv_data->null_dma_buf)
/* No target address increment */
DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
| chip->dma_width
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;
else
DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
| DCMD_FLOWSRC
| chip->dma_width
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;

Expand All @@ -756,13 +822,13 @@ static void pump_transfers(unsigned long data)
if (drv_data->tx == drv_data->null_dma_buf)
/* No source address increment */
DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
| chip->dma_width
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;
else
DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
| DCMD_FLOWTRG
| chip->dma_width
| drv_data->dma_width
| chip->dma_burst_size
| drv_data->len;

Expand Down Expand Up @@ -943,6 +1009,7 @@ static int setup(struct spi_device *spi)
clk_div = SSP3_SerClkDiv(spi->max_speed_hz);
else
return -ENODEV;
chip->speed_hz = spi->max_speed_hz;

chip->cr0 = clk_div
| SSCR0_Motorola
Expand Down Expand Up @@ -987,6 +1054,7 @@ static int setup(struct spi_device *spi)
kfree(chip);
return -ENODEV;
}
chip->bits_per_word = spi->bits_per_word;

spi_set_ctldata(spi, chip);

Expand Down

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