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>

diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c
index 5b9bc19ed134b2a4d50eb793b5d88717871df3a5..2d2bcbd80670fe63fe74fd9044f979e9436e670e 100644 (file)
--- 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;

diff --git a/drivers/tty/serial/ifx6x60.h b/drivers/tty/serial/ifx6x60.h
index e8464baf9e75d985140a038f64e008981eb0780a..d8869f5a4632cb7ec1d4165be171424c3b281720 100644 (file)
--- a/drivers/tty/serial/ifx6x60.h
+++ b/drivers/tty/serial/ifx6x60.h
@@ -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 */