spi: clps711x: Add support for 1-8 BPW transfers

This patch adds support for 1 to 8 BPW to driver and removes
excess BPW validation since this is already checked by SPI core.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-clps711x.c

@@ -32,6 +32,7 @@ struct spi_clps711x_data {
 
 	u8			*tx_buf;
 	u8			*rx_buf;
+	unsigned int		bpw;
 	int			len;
 
 	int			chipselect[0];
@@ -57,18 +58,12 @@ static void spi_clps711x_setup_mode(struct spi_device *spi)
 		clps_writew(clps_readw(SYSCON3) & ~SYSCON3_ADCCKNSEN, SYSCON3);
 }
 
-static int spi_clps711x_setup_xfer(struct spi_device *spi,
+static void spi_clps711x_setup_xfer(struct spi_device *spi,
 				    struct spi_transfer *xfer)
 {
 	u32 speed = xfer->speed_hz ? : spi->max_speed_hz;
-	u8 bpw = xfer->bits_per_word;
 	struct spi_clps711x_data *hw = spi_master_get_devdata(spi->master);
 
-	if (bpw != 8) {
-		dev_err(&spi->dev, "Unsupported master bus width %i\n", bpw);
-		return -EINVAL;
-	}
-
 	/* Setup SPI frequency divider */
 	if (!speed || (speed >= hw->max_speed_hz))
 		clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) |
@@ -82,38 +77,36 @@ static int spi_clps711x_setup_xfer(struct spi_device *spi,
 	else
 		clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) |
 			    SYSCON1_ADCKSEL(0), SYSCON1);
-
-	return 0;
 }
 
 static int spi_clps711x_transfer_one_message(struct spi_master *master,
 					     struct spi_message *msg)
 {
 	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+	struct spi_device *spi = msg->spi;
 	struct spi_transfer *xfer;
-	int status = 0, cs = hw->chipselect[msg->spi->chip_select];
+	int cs = hw->chipselect[spi->chip_select];
 
-	spi_clps711x_setup_mode(msg->spi);
+	spi_clps711x_setup_mode(spi);
 
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 		u8 data;
 
-		if (spi_clps711x_setup_xfer(msg->spi, xfer)) {
-			status = -EINVAL;
-			goto out_xfr;
-		}
+		spi_clps711x_setup_xfer(spi, xfer);
 
-		gpio_set_value(cs, !!(msg->spi->mode & SPI_CS_HIGH));
+		gpio_set_value(cs, !!(spi->mode & SPI_CS_HIGH));
 
 		reinit_completion(&hw->done);
 
 		hw->len = xfer->len;
+		hw->bpw = xfer->bits_per_word ? : spi->bits_per_word;
 		hw->tx_buf = (u8 *)xfer->tx_buf;
 		hw->rx_buf = (u8 *)xfer->rx_buf;
 
 		/* Initiate transfer */
 		data = hw->tx_buf ? *hw->tx_buf++ : 0;
-		clps_writel(data | SYNCIO_FRMLEN(8) | SYNCIO_TXFRMEN, SYNCIO);
+		clps_writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
+			    SYNCIO);
 
 		wait_for_completion(&hw->done);
 
@@ -122,13 +115,12 @@ static int spi_clps711x_transfer_one_message(struct spi_master *master,
 
 		if (xfer->cs_change ||
 		    list_is_last(&xfer->transfer_list, &msg->transfers))
-			gpio_set_value(cs, !(msg->spi->mode & SPI_CS_HIGH));
+			gpio_set_value(cs, !(spi->mode & SPI_CS_HIGH));
 
 		msg->actual_length += xfer->len;
 	}
 
-out_xfr:
-	msg->status = status;
+	msg->status = 0;
 	spi_finalize_current_message(master);
 
 	return 0;
@@ -147,7 +139,8 @@ static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
 	/* Handle TX */
 	if (--hw->len > 0) {
 		data = hw->tx_buf ? *hw->tx_buf++ : 0;
-		clps_writel(data | SYNCIO_FRMLEN(8) | SYNCIO_TXFRMEN, SYNCIO);
+		clps_writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
+			    SYNCIO);
 	} else
 		complete(&hw->done);
 
@@ -181,7 +174,7 @@ static int spi_clps711x_probe(struct platform_device *pdev)
 
 	master->bus_num = pdev->id;
 	master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
-	master->bits_per_word_mask = SPI_BPW_MASK(8);
+	master->bits_per_word_mask =  SPI_BPW_RANGE_MASK(1, 8);
 	master->num_chipselect = pdata->num_chipselect;
 	master->setup = spi_clps711x_setup;
 	master->transfer_one_message = spi_clps711x_transfer_one_message;