Commit 319fb0d2 authored by chao bi's avatar chao bi Committed by Greg Kroah-Hartman
Browse files

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: default avatarchanning <chao.bi@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent de609582

drivers/tty/serial/ifx6x60.c

+60 −10
Original line number Diff line number Diff line
@@ -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_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 = cpu_to_be16(*buf);

		buf++;

		*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;

drivers/tty/serial/ifx6x60.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

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