[PATCH 2/2] spi: mt65xx: support wider tick delay field on IPM v59

[Tim Kuo <Tim.Kuo@mediatek.com>]

The IPM v59 SPI IP widens the tick delay field in SPI_CMD_REG from
3 bits (bits 24:22) to 7 bits (bits 28:22), so the field width can no
longer be hardcoded in mtk_spi_hw_init().

Add a tick_dly_mask member to struct mtk_spi_compatible and use
field_prep() with the per-SoC mask instead of the open-coded
mask-and-shift, then add a mtk_ipm_v59_compat entry carrying the wider
mask along with a "mediatek,spi-ipm-v59" compatible. Any further changes
related to IPM v59 can be modified based on this compatible.

Existing IPM designs keep GENMASK(24, 22) and are functionally
unchanged.

Signed-off-by: Tim Kuo <Tim.Kuo@mediatek.com>
---
 drivers/spi/spi-mt65xx.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index b845a599f7c6..27ed9be1b121 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -4,6 +4,7 @@
  * Author: Leilk Liu <leilk.liu@mediatek.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -81,6 +82,7 @@
 #define SPI_CMD_IPM_GET_TICKDLY_OFFSET	22
 
 #define SPI_CMD_IPM_GET_TICKDLY_MASK	GENMASK(24, 22)
+#define SPI_CMD_IPM_V59_GET_TICKDLY_MASK	GENMASK(28, 22)
 
 #define PIN_MODE_CFG(x)	((x) / 2)
 
@@ -120,6 +122,7 @@
  * @dma_ext:		DMA address extension supported
  * @no_need_unprepare:	Don't unprepare the SPI clk during runtime
  * @ipm_design:		Adjust/extend registers to support IPM design IP features
+ * @tick_dly_mask:	Tick delay field of SPI_CMD_REG, IPM designs only
  */
 struct mtk_spi_compatible {
 	bool need_pad_sel;
@@ -128,6 +131,7 @@ struct mtk_spi_compatible {
 	bool dma_ext;
 	bool no_need_unprepare;
 	bool ipm_design;
+	u32 tick_dly_mask;
 };
 
 /**
@@ -187,6 +191,15 @@ static const struct mtk_spi_compatible mtk_ipm_compat = {
 	.enhance_timing = true,
 	.dma_ext = true,
 	.ipm_design = true,
+	.tick_dly_mask = SPI_CMD_IPM_GET_TICKDLY_MASK,
+};
+
+/* Every SoC with IPM v59 or newer shares this */
+static const struct mtk_spi_compatible mtk_ipm_v59_compat = {
+	.enhance_timing = true,
+	.dma_ext = true,
+	.ipm_design = true,
+	.tick_dly_mask = SPI_CMD_IPM_V59_GET_TICKDLY_MASK,
 };
 
 static const struct mtk_spi_compatible mt6765_compat = {
@@ -226,6 +239,7 @@ static const struct mtk_spi_compatible mt6991_compat = {
 	.enhance_timing = true,
 	.dma_ext = true,
 	.ipm_design = true,
+	.tick_dly_mask = SPI_CMD_IPM_GET_TICKDLY_MASK,
 };
 
 /*
@@ -241,6 +255,9 @@ static const struct of_device_id mtk_spi_of_match[] = {
 	{ .compatible = "mediatek,spi-ipm",
 		.data = (void *)&mtk_ipm_compat,
 	},
+	{ .compatible = "mediatek,spi-ipm-v59",
+		.data = (void *)&mtk_ipm_v59_compat,
+	},
 	{ .compatible = "mediatek,mt2701-spi",
 		.data = (void *)&mtk_common_compat,
 	},
@@ -366,7 +383,7 @@ static int mtk_spi_hw_init(struct spi_controller *host,
 			   struct spi_device *spi)
 {
 	u16 cpha, cpol;
-	u32 reg_val;
+	u32 reg_val, mask;
 	struct mtk_chip_config *chip_config = spi->controller_data;
 	struct mtk_spi *mdata = spi_controller_get_devdata(host);
 
@@ -443,10 +460,10 @@ static int mtk_spi_hw_init(struct spi_controller *host,
 	/* tick delay */
 	if (mdata->dev_comp->enhance_timing) {
 		if (mdata->dev_comp->ipm_design) {
+			mask = mdata->dev_comp->tick_dly_mask;
 			reg_val = readl(mdata->base + SPI_CMD_REG);
-			reg_val &= ~SPI_CMD_IPM_GET_TICKDLY_MASK;
-			reg_val |= ((chip_config->tick_delay & 0x7)
-				    << SPI_CMD_IPM_GET_TICKDLY_OFFSET);
+			reg_val &= ~mask;
+			reg_val |= field_prep(mask, chip_config->tick_delay);
 			writel(reg_val, mdata->base + SPI_CMD_REG);
 		} else {
 			reg_val = readl(mdata->base + SPI_CFG1_REG);
-- 
2.45.2