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spi: mediatek: adjust register to enhance time accuracy 

this patch adjust register to enhance time accuracy.

Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
hifive-unleashed-5.1
Leilk Liu 2017-06-12 09:24:39 +08:00 committed by Mark Brown
parent d27ae103bf
commit 058fe49da3
2 changed files with 42 additions and 5 deletions
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45
drivers/spi/spi-mt65xx.c
View File

@ -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 @@ static const struct mtk_spi_compatible mt8173_compat = {
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;

2
include/linux/platform_data/spi-mt65xx.h
View File

@ -16,5 +16,7 @@
struct mtk_chip_config {
u32 tx_mlsb;
u32 rx_mlsb;
u32 cs_pol;
u32 sample_sel;
};
#endif