Commit 0c92ecf1 authored by Jassi Brar's avatar Jassi Brar Committed by Grant Likely
Browse files

spi/s3c64xx: Correction for 16,32 bits bus width 



We can't do without setting channel and bus width to
same size. In order to do that, use loop read/writes in
polling mode and appropriate burst size in DMA mode.

Signed-off-by: default avatarJassi Brar <jassi.brar@samsung.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent b42a81ca

drivers/spi/spi_s3c64xx.c

+41 −15
Original line number Diff line number Diff line
@@ -261,15 +261,25 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd, 
		chcfg |= S3C64XX_SPI_CH_TXCH_ON;

		if (dma_mode) {

			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;

			s3c2410_dma_config(sdd->tx_dmach, 1);

			s3c2410_dma_config(sdd->tx_dmach, sdd->cur_bpw / 8);

			s3c2410_dma_enqueue(sdd->tx_dmach, (void *)sdd,

						xfer->tx_dma, xfer->len);

			s3c2410_dma_ctrl(sdd->tx_dmach, S3C2410_DMAOP_START);

		} else {

			unsigned char *buf = (unsigned char *) xfer->tx_buf;

			int i = 0;

			while (i < xfer->len)

				writeb(buf[i++], regs + S3C64XX_SPI_TX_DATA);

			switch (sdd->cur_bpw) {

			case 32:

				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,

					xfer->tx_buf, xfer->len / 4);

				break;

			case 16:

				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,

					xfer->tx_buf, xfer->len / 2);

				break;

			default:

				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,

					xfer->tx_buf, xfer->len);

				break;

			}

		}

	}
@@ -286,7 +296,7 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd, 
			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)

					| S3C64XX_SPI_PACKET_CNT_EN,

					regs + S3C64XX_SPI_PACKET_CNT);

			s3c2410_dma_config(sdd->rx_dmach, 1);

			s3c2410_dma_config(sdd->rx_dmach, sdd->cur_bpw / 8);

			s3c2410_dma_enqueue(sdd->rx_dmach, (void *)sdd,

						xfer->rx_dma, xfer->len);

			s3c2410_dma_ctrl(sdd->rx_dmach, S3C2410_DMAOP_START);
@@ -366,20 +376,26 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, 
				return -EIO;

		}

	} else {

		unsigned char *buf;

		int i;



		/* If it was only Tx */

		if (xfer->rx_buf == NULL) {

			sdd->state &= ~TXBUSY;

			return 0;

		}



		i = 0;

		buf = xfer->rx_buf;

		while (i < xfer->len)

			buf[i++] = readb(regs + S3C64XX_SPI_RX_DATA);



		switch (sdd->cur_bpw) {

		case 32:

			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,

				xfer->rx_buf, xfer->len / 4);

			break;

		case 16:

			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,

				xfer->rx_buf, xfer->len / 2);

			break;

		default:

			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,

				xfer->rx_buf, xfer->len);

			break;

		}

		sdd->state &= ~RXBUSY;

	}
@@ -434,15 +450,17 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) 
	switch (sdd->cur_bpw) {

	case 32:

		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;

		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;

		break;

	case 16:

		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;

		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;

		break;

	default:

		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;

		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;

		break;

	}

	val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE; /* Always 8bits wide */



	writel(val, regs + S3C64XX_SPI_MODE_CFG);
@@ -629,6 +647,14 @@ static void handle_msg(struct s3c64xx_spi_driver_data *sdd, 
		bpw = xfer->bits_per_word ? : spi->bits_per_word;

		speed = xfer->speed_hz ? : spi->max_speed_hz;



		if (xfer->len % (bpw / 8)) {

			dev_err(&spi->dev,

				"Xfer length(%u) not a multiple of word size(%u)\n",

				xfer->len, bpw / 8);

			status = -EIO;

			goto out;

		}



		if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {

			sdd->cur_bpw = bpw;

			sdd->cur_speed = speed;