spi: mediatek: add SPI_CS_HIGH support

Change to use SPI_CS_HIGH to support spi CS polarity setting
for chips support enhance_timing.

Signed-off-by: Luhua Xu <luhua.xu@mediatek.com>
Link: https://lore.kernel.org/r/1574053037-26721-2-git-send-email-luhua.xu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-mt65xx.c

@@ -139,7 +139,6 @@ static const struct mtk_spi_compatible mt8183_compat = {
  * supplies it.
  */
 static const struct mtk_chip_config mtk_default_chip_info = {
-	.cs_pol = 0,
 	.sample_sel = 0,
 };
 
@@ -230,10 +229,12 @@ static int mtk_spi_prepare_message(struct spi_master *master,
 #endif
 
 	if (mdata->dev_comp->enhance_timing) {
-		if (chip_config->cs_pol)
+		/* set CS polarity */
+		if (spi->mode & SPI_CS_HIGH)
 			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
@@ -264,6 +265,9 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
 	u32 reg_val;
 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
 
+	if (spi->mode & SPI_CS_HIGH)
+		enable = !enable;
+
 	reg_val = readl(mdata->base + SPI_CMD_REG);
 	if (!enable) {
 		reg_val |= SPI_CMD_PAUSE_EN;
@@ -646,6 +650,10 @@ static int mtk_spi_probe(struct platform_device *pdev)
 
 	mdata = spi_master_get_devdata(master);
 	mdata->dev_comp = of_id->data;
+
+	if (mdata->dev_comp->enhance_timing)
+		master->mode_bits |= SPI_CS_HIGH;
+
 	if (mdata->dev_comp->must_tx)
 		master->flags = SPI_MASTER_MUST_TX;
 

include/linux/platform_data/spi-mt65xx.h

@@ -11,7 +11,6 @@
 
 /* Board specific platform_data */
 struct mtk_chip_config {
-	u32 cs_pol;
 	u32 sample_sel;
 };
 #endif