diff options
author | chao bi <chao.bi@intel.com> | 2012-10-25 09:02:32 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-25 11:29:58 -0700 |
commit | 319fb0d21907f771d8ccdb6177fb2fcafabc6ab4 (patch) | |
tree | 9f6293ef3a34c288ad25a9638ec6bc463027d3cb /drivers/tty/serial/ifx6x60.c | |
parent | de609582072af195673e72d9e7647d5cba8eb7e4 (diff) | |
download | linux-319fb0d21907f771d8ccdb6177fb2fcafabc6ab4.tar.bz2 |
serial: ifx6x60: different SPI word width configure requires different swap process
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>
Diffstat (limited to 'drivers/tty/serial/ifx6x60.c')
-rw-r--r-- | drivers/tty/serial/ifx6x60.c | 70 |
1 files changed, 60 insertions, 10 deletions
diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c index 5b9bc19ed134..2d2bcbd80670 100644 --- a/drivers/tty/serial/ifx6x60.c +++ b/drivers/tty/serial/ifx6x60.c @@ -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; |