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authorEmil Renner Berthing <kernel@esmil.dk>2018-10-31 13:57:10 +0300
committerMark Brown <broonie@kernel.org>2018-11-05 14:42:39 +0300
commit65498c6ae2414a1425aa6c4231e79e2998afec05 (patch)
tree70cca0880cc8557f3855bb1d338ceaa1661fab53 /drivers/spi/spi-rockchip.c
parent01b59ce5dac856323a0c13c1d51d99a819f32efe (diff)
downloadlinux-65498c6ae2414a1425aa6c4231e79e2998afec05.tar.xz
spi: rockchip: support 4bit words
The hardware supports 4, 8 and 16bit spi words, so add the missing support for 4bit words. Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> Tested-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-rockchip.c')
-rw-r--r--drivers/spi/spi-rockchip.c41
1 files changed, 29 insertions, 12 deletions
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 1297f081818d..9e47e81553a1 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -54,6 +54,9 @@
/* Bit fields in CTRLR0 */
#define CR0_DFS_OFFSET 0
+#define CR0_DFS_4BIT 0x0
+#define CR0_DFS_8BIT 0x1
+#define CR0_DFS_16BIT 0x2
#define CR0_CFS_OFFSET 2
@@ -464,15 +467,14 @@ static void rockchip_spi_config(struct rockchip_spi *rs,
struct spi_device *spi, struct spi_transfer *xfer,
bool use_dma)
{
- u32 dmacr = 0;
-
u32 cr0 = CR0_FRF_SPI << CR0_FRF_OFFSET
| CR0_BHT_8BIT << CR0_BHT_OFFSET
| CR0_SSD_ONE << CR0_SSD_OFFSET
| CR0_EM_BIG << CR0_EM_OFFSET;
+ u32 cr1;
+ u32 dmacr = 0;
cr0 |= rs->rsd << CR0_RSD_OFFSET;
- cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
if (xfer->rx_buf && xfer->tx_buf)
@@ -482,6 +484,27 @@ static void rockchip_spi_config(struct rockchip_spi *rs,
else if (use_dma)
cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
+ switch (xfer->bits_per_word) {
+ case 4:
+ cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
+ cr1 = xfer->len - 1;
+ break;
+ case 8:
+ cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
+ cr1 = xfer->len - 1;
+ break;
+ case 16:
+ cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
+ cr1 = xfer->len / 2 - 1;
+ break;
+ default:
+ /* we only whitelist 4, 8 and 16 bit words in
+ * master->bits_per_word_mask, so this shouldn't
+ * happen
+ */
+ unreachable();
+ }
+
if (use_dma) {
if (xfer->tx_buf)
dmacr |= TF_DMA_EN;
@@ -490,13 +513,7 @@ static void rockchip_spi_config(struct rockchip_spi *rs,
}
writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
-
- if (rs->n_bytes == 1)
- writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
- else if (rs->n_bytes == 2)
- writel_relaxed((xfer->len / 2) - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
- else
- writel_relaxed((xfer->len * 2) - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
+ writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
/* unfortunately setting the fifo threshold level to generate an
* interrupt exactly when the fifo is full doesn't seem to work,
@@ -545,7 +562,7 @@ static int rockchip_spi_transfer_one(
return -EINVAL;
}
- rs->n_bytes = xfer->bits_per_word >> 3;
+ rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
use_dma = master->can_dma ? master->can_dma(master, spi, xfer) : false;
@@ -667,7 +684,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
master->dev.of_node = pdev->dev.of_node;
- master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
+ master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
master->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
master->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);