this patch adjust register to enhance time accuracy.
Signed-off-by: Leilk Liu <leilk.liu@xxxxxxxxxxxx>
---
drivers/spi/spi-mt65xx.c | 45 ++++++++++++++++++++++++++----
include/linux/platform_data/spi-mt65xx.h | 2 ++
2 files changed, 42 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 278867a..eae73b5 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -35,11 +35,15 @@
#define SPI_CMD_REG 0x0018
#define SPI_STATUS0_REG 0x001c
#define SPI_PAD_SEL_REG 0x0024
+#define SPI_CFG2_REG 0x0028
#define SPI_CFG0_SCK_HIGH_OFFSET 0
#define SPI_CFG0_SCK_LOW_OFFSET 8
#define SPI_CFG0_CS_HOLD_OFFSET 16
#define SPI_CFG0_CS_SETUP_OFFSET 24
+#define SPI_ADJUST_CFG0_SCK_LOW_OFFSET 16
+#define SPI_ADJUST_CFG0_CS_HOLD_OFFSET 0
+#define SPI_ADJUST_CFG0_CS_SETUP_OFFSET 16
#define SPI_CFG1_CS_IDLE_OFFSET 0
#define SPI_CFG1_PACKET_LOOP_OFFSET 8
@@ -55,6 +59,8 @@
#define SPI_CMD_RST BIT(2)
#define SPI_CMD_PAUSE_EN BIT(4)
#define SPI_CMD_DEASSERT BIT(5)
+#define SPI_CMD_SAMPLE_SEL BIT(6)
+#define SPI_CMD_CS_POL BIT(7)
#define SPI_CMD_CPHA BIT(8)
#define SPI_CMD_CPOL BIT(9)
#define SPI_CMD_RX_DMA BIT(10)
@@ -80,6 +86,8 @@ struct mtk_spi_compatible {
bool need_pad_sel;
/* Must explicitly send dummy Tx bytes to do Rx only transfer */
bool must_tx;
+ /* some IC design adjust cfg register to enhance time accuracy */
+ bool enhance_timing;
};
struct mtk_spi {
@@ -108,6 +116,8 @@ struct mtk_spi {
static const struct mtk_chip_config mtk_default_chip_info = {
.rx_mlsb = 1,
.tx_mlsb = 1,
+ .cs_pol = 0,
+ .sample_sel = 0,
};
static const struct of_device_id mtk_spi_of_match[] = {
@@ -182,6 +192,17 @@ static int mtk_spi_prepare_message(struct spi_master *master,
reg_val |= SPI_CMD_RX_ENDIAN;
#endif
+ if (mdata->dev_comp->enhance_timing) {
+ if (chip_config->cs_pol)
+ reg_val |= SPI_CMD_CS_POL;
+ else
+ reg_val &= ~SPI_CMD_CS_POL;
+ if (chip_config->sample_sel)
+ reg_val |= SPI_CMD_SAMPLE_SEL;
+ else
+ reg_val &= ~SPI_CMD_SAMPLE_SEL;
+ }
+
/* set finish and pause interrupt always enable */
reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
@@ -233,11 +254,25 @@ static void mtk_spi_prepare_transfer(struct spi_master *master,
sck_time = (div + 1) / 2;
cs_time = sck_time * 2;
- reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_HIGH_OFFSET);
- reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
- reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
- reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
- writel(reg_val, mdata->base + SPI_CFG0_REG);
+ if (mdata->dev_comp->enhance_timing) {
+ reg_val |= (((sck_time - 1) & 0xffff)
+ << SPI_CFG0_SCK_HIGH_OFFSET);
+ reg_val |= (((sck_time - 1) & 0xffff)
+ << SPI_ADJUST_CFG0_SCK_LOW_OFFSET);
+ writel(reg_val, mdata->base + SPI_CFG2_REG);
+ reg_val |= (((cs_time - 1) & 0xffff)
+ << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
+ reg_val |= (((cs_time - 1) & 0xffff)
+ << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
+ writel(reg_val, mdata->base + SPI_CFG0_REG);
+ } else {
+ reg_val |= (((sck_time - 1) & 0xff)
+ << SPI_CFG0_SCK_HIGH_OFFSET);
+ reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
+ reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
+ reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
+ writel(reg_val, mdata->base + SPI_CFG0_REG);
+ }
reg_val = readl(mdata->base + SPI_CFG1_REG);
reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
diff --git a/include/linux/platform_data/spi-mt65xx.h b/include/linux/platform_data/spi-mt65xx.h
index 54b0448..ba4e4bb 100644
--- a/include/linux/platform_data/spi-mt65xx.h
+++ b/include/linux/platform_data/spi-mt65xx.h
@@ -16,5 +16,7 @@
struct mtk_chip_config {
u32 tx_mlsb;
u32 rx_mlsb;
+ u32 cs_pol;
+ u32 sample_sel;
};
#endif
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
