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Commit 5c2818cd authored by Cory Maccarrone's avatar Cory Maccarrone Committed by Grant Likely
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SPI100k: Fix 8-bit and RX-only transfers 



This change fixes 8-bit transfers and RX-only transfers.  The
SPI100k framework requires minimum 16-bit words to be written, so 8-bit
transfers must be shited by 8 bits and sent out as a 16-bit word.

Additionally, receive-only transfers were failing due to the
perceived need to fill the TX buffer with something.  This is in
fact not needed.

Signed-off-by: default avatarCory Maccarrone <darkstar6262@gmail.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 4751c1c7

drivers/spi/omap_spi_100k.c

+12 −11
Original line number Original line Diff line number Diff line
@@ -141,7 +141,12 @@ static void spi100k_write_data(struct spi_master *master, int len, int data) 
{

{

	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);

	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);





	/* write 16-bit word */

	/* write 16-bit word, shifting 8-bit data if necessary */

	if (len <= 8) {

		data <<= 8;

		len = 16;

	}



	spi100k_enable_clock(master);

	spi100k_enable_clock(master);

	writew( data , spi100k->base + SPI_TX_MSB);

	writew( data , spi100k->base + SPI_TX_MSB);
@@ -162,6 +167,10 @@ static int spi100k_read_data(struct spi_master *master, int len) 
	int dataH,dataL;

	int dataH,dataL;

	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);

	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);





	/* Always do at least 16 bits */

	if (len <= 8)

		len = 16;



	spi100k_enable_clock(master);

	spi100k_enable_clock(master);

	writew(SPI_CTRL_SEN(0) |

	writew(SPI_CTRL_SEN(0) |

	       SPI_CTRL_WORD_SIZE(len) |

	       SPI_CTRL_WORD_SIZE(len) |
@@ -214,10 +223,6 @@ omap1_spi100k_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) 
	c = count;

	c = count;

	word_len = cs->word_len;

	word_len = cs->word_len;





	/* RX_ONLY mode needs dummy data in TX reg */

	if (xfer->tx_buf == NULL)

		spi100k_write_data(spi->master,word_len, 0);



	if (word_len <= 8) {

	if (word_len <= 8) {

		u8              *rx;

		u8              *rx;

		const u8        *tx;

		const u8        *tx;
@@ -227,9 +232,9 @@ omap1_spi100k_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) 
		do {

		do {

			c-=1;

			c-=1;

			if (xfer->tx_buf != NULL)

			if (xfer->tx_buf != NULL)

				spi100k_write_data(spi->master,word_len, *tx);

				spi100k_write_data(spi->master, word_len, *tx++);

			if (xfer->rx_buf != NULL)

			if (xfer->rx_buf != NULL)

				*rx = spi100k_read_data(spi->master,word_len);

				*rx++ = spi100k_read_data(spi->master, word_len);

		} while(c);

		} while(c);

	} else if (word_len <= 16) {

	} else if (word_len <= 16) {

		u16             *rx;

		u16             *rx;
@@ -380,10 +385,6 @@ static void omap1_spi100k_work(struct work_struct *work) 
			if (t->len) {

			if (t->len) {

				unsigned count;

				unsigned count;





				/* RX_ONLY mode needs dummy data in TX reg */

				if (t->tx_buf == NULL)

					spi100k_write_data(spi->master, 8, 0);



				count = omap1_spi100k_txrx_pio(spi, t);

				count = omap1_spi100k_txrx_pio(spi, t);

				m->actual_length += count;

				m->actual_length += count;