[PATCH V2 2/3] pwm: Add MediaTek MT2701 display PWM driver support

[Weiqing Kong]

Use the mtk_pwm_data struction to define different registers
and add MT2701 specific register operations, such as MT2701
doesn't have commit register, needs to disable double buffer
before writing register, and needs to select manual mode
and use PWM_PERIOD/PWM_HIGH_WIDTH.

Signed-off-by: Weiqing Kong <weiqing.kong@xxxxxxxxxxxx>
---
 drivers/pwm/pwm-mtk-disp.c | 99 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 80 insertions(+), 19 deletions(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 0ad3385..5eb1f6c 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -18,33 +18,45 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
 
 #define DISP_PWM_EN		0x00
-#define PWM_ENABLE_MASK		BIT(0)
 
-#define DISP_PWM_COMMIT		0x08
-#define PWM_COMMIT_MASK		BIT(0)
+#define MT8173_PWM_COMMIT_MASK		BIT(0)
 
-#define DISP_PWM_CON_0		0x10
 #define PWM_CLKDIV_SHIFT	16
 #define PWM_CLKDIV_MAX		0x3ff
 #define PWM_CLKDIV_MASK		(PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
 
-#define DISP_PWM_CON_1		0x14
 #define PWM_PERIOD_BIT_WIDTH	12
 #define PWM_PERIOD_MASK		((1 << PWM_PERIOD_BIT_WIDTH) - 1)
 
 #define PWM_HIGH_WIDTH_SHIFT	16
 #define PWM_HIGH_WIDTH_MASK	(0x1fff << PWM_HIGH_WIDTH_SHIFT)
 
+#define MT2701_PWM_MANUAL_SEL_MASK	BIT(1)
+#define MT2701_PWM_BLS_DEBUG		0xb0
+#define MT2701_PWM_BLS_DEBUG_MASK	0x3
+
+struct mtk_pwm_data {
+	unsigned int bls_debug;
+	unsigned int enable_bit;
+	unsigned int con0;
+	unsigned int con0_sel;
+	unsigned int con1;
+	unsigned int commit_reg_offset;
+	bool have_commit_reg;
+};
+
 struct mtk_disp_pwm {
 	struct pwm_chip chip;
 	struct clk *clk_main;
 	struct clk *clk_mm;
 	void __iomem *base;
+	const struct mtk_pwm_data *data;
 };
 
 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
@@ -106,12 +118,18 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return err;
 	}
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_CON_0, PWM_CLKDIV_MASK,
+	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
+				 PWM_CLKDIV_MASK,
 				 clk_div << PWM_CLKDIV_SHIFT);
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_CON_1,
-				 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK, value);
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT, PWM_COMMIT_MASK, 1);
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT, PWM_COMMIT_MASK, 0);
+	mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
+				 PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
+				 value);
+	if (mdp->data->have_commit_reg) {
+		mtk_disp_pwm_update_bits(mdp, mdp->data->commit_reg_offset,
+					 MT8173_PWM_COMMIT_MASK, 0x1);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->commit_reg_offset,
+					 MT8173_PWM_COMMIT_MASK, 0x0);
+	}
 
 	clk_disable(mdp->clk_mm);
 	clk_disable(mdp->clk_main);
@@ -134,7 +152,9 @@ static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 		return err;
 	}
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, PWM_ENABLE_MASK, 1);
+	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
+				 mdp->data->enable_bit,
+				 mdp->data->enable_bit);
 
 	return 0;
 }
@@ -143,7 +163,8 @@ static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, PWM_ENABLE_MASK, 0);
+	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
+				 mdp->data->enable_bit, 0x0);
 
 	clk_disable(mdp->clk_mm);
 	clk_disable(mdp->clk_main);
@@ -156,12 +177,45 @@ static const struct pwm_ops mtk_disp_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
+static const struct mtk_pwm_data mt8173_pwm_data = {
+	.bls_debug = 0x0,
+	.enable_bit = BIT(0),
+	.con0 = 0x10,
+	.con0_sel = 0x0,
+	.con1 = 0x14,
+	.commit_reg_offset = 0x8,
+	.have_commit_reg = true,
+};
+
+static const struct mtk_pwm_data mt2701_pwm_data = {
+	.bls_debug = 0x3,
+	.enable_bit = BIT(16),
+	.con0 = 0xa8,
+	.con0_sel = 0x2,
+	.con1 = 0xac,
+	.commit_reg_offset = 0x0,
+	.have_commit_reg = false,
+};
+
+static const struct of_device_id mtk_disp_pwm_of_match[] = {
+	{ .compatible = "mediatek,mt2701-disp-pwm", .data = &mt2701_pwm_data},
+	{ .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
+	{ .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
+
 static int mtk_disp_pwm_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *id;
 	struct mtk_disp_pwm *mdp;
 	struct resource *r;
 	int ret;
 
+	id = of_match_device(mtk_disp_pwm_of_match, &pdev->dev);
+	if (!id)
+		return -EINVAL;
+
 	mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
 	if (!mdp)
 		return -ENOMEM;
@@ -191,6 +245,7 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	mdp->chip.ops = &mtk_disp_pwm_ops;
 	mdp->chip.base = -1;
 	mdp->chip.npwm = 1;
+	mdp->data = id->data;
 
 	ret = pwmchip_add(&mdp->chip);
 	if (ret < 0) {
@@ -200,6 +255,19 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mdp);
 
+	/*
+	 * For MT2701, disable double buffer before writing register
+	 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
+	 */
+	if (!mdp->data->have_commit_reg) {
+		mtk_disp_pwm_update_bits(mdp, MT2701_PWM_BLS_DEBUG,
+					 MT2701_PWM_BLS_DEBUG_MASK,
+					 mdp->data->bls_debug);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
+					 MT2701_PWM_MANUAL_SEL_MASK,
+					 mdp->data->con0_sel);
+	}
+
 	return 0;
 
 disable_clk_mm:
@@ -221,13 +289,6 @@ static int mtk_disp_pwm_remove(struct platform_device *pdev)
 	return ret;
 }
 
-static const struct of_device_id mtk_disp_pwm_of_match[] = {
-	{ .compatible = "mediatek,mt8173-disp-pwm" },
-	{ .compatible = "mediatek,mt6595-disp-pwm" },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
-
 static struct platform_driver mtk_disp_pwm_driver = {
 	.driver = {
 		.name = "mediatek-disp-pwm",
-- 
1.8.1.1.dirty