Commit 058fe49d authored by Leilk Liu's avatar Leilk Liu Committed by Mark Brown
Browse files

spi: mediatek: adjust register to enhance time accuracy 



this patch adjust register to enhance time accuracy.

Signed-off-by: default avatarLeilk Liu <leilk.liu@mediatek.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent d27ae103

drivers/spi/spi-mt65xx.c

+40 −5
Original line number Diff line number Diff line
@@ -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);

	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;

include/linux/platform_data/spi-mt65xx.h

+2 −0
Original line number Diff line number Diff line
@@ -16,5 +16,7 @@ 
struct mtk_chip_config {

	u32 tx_mlsb;

	u32 rx_mlsb;

	u32 cs_pol;

	u32 sample_sel;

};

#endif