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serial: ifx6x60: different SPI word width configure requires different swap process

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SPI protocol driver only provide one function (swap_buf()) to swap SPI
data into big endian format, which is only available when SPI
controller's word width is 16 bits. But word width could be configured
as 8/16/32 bits, different word width configure should be mapped to
different swap methods.This patch is to make SPI protocol driver choose
the right swap function corresponding to SPI word width configuration.

cc: liu chuansheng <chuansheng.liu@intel.com>
cc: Chen Jun <jun.d.chen@intel.com>
Signed-off-by: channing <chao.bi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
chao bi 2012-10-25 09:02:32 +08:00 committed by Greg Kroah-Hartman
parent de60958207
commit 319fb0d219
2 changed files with 61 additions and 10 deletions
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70
drivers/tty/serial/ifx6x60.c
View File

@ -152,26 +152,67 @@ ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
}
/**
* swap_buf
* swap_buf_8
* @buf: our buffer
* @len : number of bytes (not words) in the buffer
* @end: end of buffer
*
* Swap the contents of a buffer into big endian format
*/
static inline void swap_buf(u16 *buf, int len, void *end)
static inline void swap_buf_8(unsigned char *buf, int len, void *end)
{
/* don't swap buffer if SPI word width is 8 bits */
return;
}
/**
* swap_buf_16
* @buf: our buffer
* @len : number of bytes (not words) in the buffer
* @end: end of buffer
*
* Swap the contents of a buffer into big endian format
*/
static inline void swap_buf_16(unsigned char *buf, int len, void *end)
{
int n;
u16 *buf_16 = (u16 *)buf;
len = ((len + 1) >> 1);
if ((void *)&buf[len] > end) {
pr_err("swap_buf: swap exceeds boundary (%p > %p)!",
&buf[len], end);
if ((void *)&buf_16[len] > end) {
pr_err("swap_buf_16: swap exceeds boundary (%p > %p)!",
&buf_16[len], end);
return;
}
for (n = 0; n < len; n++) {
*buf = cpu_to_be16(*buf);
buf++;
*buf_16 = cpu_to_be16(*buf_16);
buf_16++;
}
}
/**
* swap_buf_32
* @buf: our buffer
* @len : number of bytes (not words) in the buffer
* @end: end of buffer
*
* Swap the contents of a buffer into big endian format
*/
static inline void swap_buf_32(unsigned char *buf, int len, void *end)
{
int n;
u32 *buf_32 = (u32 *)buf;
len = (len + 3) >> 2;
if ((void *)&buf_32[len] > end) {
pr_err("swap_buf_32: swap exceeds boundary (%p > %p)!\n",
&buf_32[len], end);
return;
}
for (n = 0; n < len; n++) {
*buf_32 = cpu_to_be32(*buf_32);
buf_32++;
}
}
@ -449,7 +490,7 @@ static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
tx_count-IFX_SPI_HEADER_OVERHEAD,
ifx_dev->spi_more);
/* swap actual data in the buffer */
swap_buf((u16 *)(ifx_dev->tx_buffer), tx_count,
ifx_dev->swap_buf((ifx_dev->tx_buffer), tx_count,
&ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
return tx_count;
}
@ -617,7 +658,7 @@ static void ifx_spi_complete(void *ctx)
if (!ifx_dev->spi_msg.status) {
/* check header validity, get comm flags */
swap_buf((u16 *)ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
ifx_dev->swap_buf(ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
&ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
&length, &more, &cts);
@ -636,7 +677,8 @@ static void ifx_spi_complete(void *ctx)
actual_length = min((unsigned int)length,
ifx_dev->spi_msg.actual_length);
swap_buf((u16 *)(ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
ifx_dev->swap_buf(
(ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
actual_length,
&ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
ifx_spi_insert_flip_string(
@ -1001,6 +1043,14 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
return -ENODEV;
}
/* init swap_buf function according to word width configuration */
if (spi->bits_per_word == 32)
ifx_dev->swap_buf = swap_buf_32;
else if (spi->bits_per_word == 16)
ifx_dev->swap_buf = swap_buf_16;
else
ifx_dev->swap_buf = swap_buf_8;
/* ensure SPI protocol flags are initialized to enable transfer */
ifx_dev->spi_more = 0;
ifx_dev->spi_slave_cts = 0;

1
drivers/tty/serial/ifx6x60.h
View File

@ -124,6 +124,7 @@ struct ifx_spi_device {
#define MR_INPROGRESS 1
#define MR_COMPLETE 2
wait_queue_head_t mdm_reset_wait;
void (*swap_buf)(unsigned char *buf, int len, void *end);
};
#endif /* _IFX6X60_H */