pwm: Add MediaTek MT2701 display PWM driver support

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@mediatek.com>
[thierry.reding@gmail.com: use of_device_get_match_data()]
[thierry.reding@gmail.com: parameterize more consistently]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-mtk-disp.c

@@ -18,30 +18,40 @@
 #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 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)
 
+struct mtk_pwm_data {
+	u32 enable_mask;
+	unsigned int con0;
+	u32 con0_sel;
+	unsigned int con1;
+
+	bool has_commit;
+	unsigned int commit;
+	unsigned int commit_mask;
+
+	unsigned int bls_debug;
+	u32 bls_debug_mask;
+};
+
 struct mtk_disp_pwm {
 	struct pwm_chip chip;
+	const struct mtk_pwm_data *data;
 	struct clk *clk_main;
 	struct clk *clk_mm;
 	void __iomem *base;
@@ -106,12 +116,21 @@ 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->has_commit) {
+		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
+					 mdp->data->commit_mask,
+					 mdp->data->commit_mask);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
+					 mdp->data->commit_mask,
+					 0x0);
+	}
 
 	clk_disable(mdp->clk_mm);
 	clk_disable(mdp->clk_main);
@@ -134,7 +153,8 @@ 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_mask,
+				 mdp->data->enable_mask);
 
 	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_mask,
+				 0x0);
 
 	clk_disable(mdp->clk_mm);
 	clk_disable(mdp->clk_main);
@@ -166,6 +187,8 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	if (!mdp)
 		return -ENOMEM;
 
+	mdp->data = of_device_get_match_data(&pdev->dev);
+
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	mdp->base = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(mdp->base))
@@ -200,6 +223,19 @@ 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->has_commit) {
+		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
+					 mdp->data->bls_debug_mask,
+					 mdp->data->bls_debug_mask);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
+					 mdp->data->con0_sel,
+					 mdp->data->con0_sel);
+	}
+
 	return 0;
 
 disable_clk_mm:
@@ -221,9 +257,30 @@ static int mtk_disp_pwm_remove(struct platform_device *pdev)
 	return ret;
 }
 
+static const struct mtk_pwm_data mt2701_pwm_data = {
+	.enable_mask = BIT(16),
+	.con0 = 0xa8,
+	.con0_sel = 0x2,
+	.con1 = 0xac,
+	.has_commit = false,
+	.bls_debug = 0xb0,
+	.bls_debug_mask = 0x3,
+};
+
+static const struct mtk_pwm_data mt8173_pwm_data = {
+	.enable_mask = BIT(0),
+	.con0 = 0x10,
+	.con0_sel = 0x0,
+	.con1 = 0x14,
+	.has_commit = true,
+	.commit = 0x8,
+	.commit_mask = 0x1,
+};
+
 static const struct of_device_id mtk_disp_pwm_of_match[] = {
-	{ .compatible = "mediatek,mt8173-disp-pwm" },
-	{ .compatible = "mediatek,mt6595-disp-pwm" },
+	{ .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);