[PATCH 2/2] pwm: sophgo: add driver for SG2044

[Longbin Li <looong.bin@gmail.com>]

From: ghost <2990955050@qq.com>

Add PWM controller for SG2044.

Signed-off-by: Longbin Li <looong.bin@gmail.com>
---
 drivers/pwm/pwm-sophgo-sg2042.c | 162 +++++++++++++++++++++++++++-----
 1 file changed, 138 insertions(+), 24 deletions(-)

diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
index ff4639d849ce..c62e8c758d87 100644
--- a/drivers/pwm/pwm-sophgo-sg2042.c
+++ b/drivers/pwm/pwm-sophgo-sg2042.c
@@ -26,20 +26,22 @@
 #include <linux/pwm.h>
 #include <linux/reset.h>

-/*
- * Offset RegisterName
- * 0x0000 HLPERIOD0
- * 0x0004 PERIOD0
- * 0x0008 HLPERIOD1
- * 0x000C PERIOD1
- * 0x0010 HLPERIOD2
- * 0x0014 PERIOD2
- * 0x0018 HLPERIOD3
- * 0x001C PERIOD3
- * Four groups and every group is composed of HLPERIOD & PERIOD
- */
-#define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
-#define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)
+#define REG_HLPERIOD		0x0
+#define REG_PERIOD		0x4
+#define REG_GROUP		0x8
+#define REG_POLARITY		0x40
+
+#define REG_PWMSTART		0x44
+#define REG_PWMUPDATE		0x4C
+#define REG_SHIFTCOUNT		0x80
+#define REG_SHIFTSTART		0x90
+#define REG_PWM_OE		0xD0
+
+#define PWM_REG_NUM		0x80
+
+#define PWM_POLARITY_MASK(n) BIT(n)
+#define PWM_HLPERIOD(chan) ((chan) * REG_GROUP + REG_HLPERIOD)
+#define PWM_PERIOD(chan) ((chan) * REG_GROUP + REG_PERIOD)

 #define SG2042_PWM_CHANNELNUM	4

@@ -51,6 +53,12 @@
 struct sg2042_pwm_ddata {
 	void __iomem *base;
 	unsigned long clk_rate_hz;
+	struct mutex lock;
+};
+
+struct sg2042_chip_data {
+	const struct pwm_ops ops;
+	bool atomic;
 };

 /*
@@ -62,8 +70,8 @@ static void pwm_sg2042_config(struct sg2042_pwm_ddata *ddata, unsigned int chan,
 {
 	void __iomem *base = ddata->base;

-	writel(period_ticks, base + SG2042_PWM_PERIOD(chan));
-	writel(hlperiod_ticks, base + SG2042_PWM_HLPERIOD(chan));
+	writel(period_ticks, base + PWM_PERIOD(chan));
+	writel(hlperiod_ticks, base + PWM_HLPERIOD(chan));
 }

 static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -104,8 +112,8 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	u32 hlperiod_ticks;
 	u32 period_ticks;

-	period_ticks = readl(ddata->base + SG2042_PWM_PERIOD(chan));
-	hlperiod_ticks = readl(ddata->base + SG2042_PWM_HLPERIOD(chan));
+	period_ticks = readl(ddata->base + PWM_PERIOD(chan));
+	hlperiod_ticks = readl(ddata->base + PWM_HLPERIOD(chan));

 	if (!period_ticks) {
 		state->enabled = false;
@@ -123,13 +131,112 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	return 0;
 }

-static const struct pwm_ops pwm_sg2042_ops = {
-	.apply = pwm_sg2042_apply,
-	.get_state = pwm_sg2042_get_state,
+static void pwm_sg2044_config(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm, bool enabled)
+{
+	u32 pwm_value;
+
+	pwm_value = readl(ddata->base + REG_PWMSTART);
+
+	if (enabled)
+		writel(pwm_value | BIT(pwm->hwpwm), ddata->base + REG_PWMSTART);
+	else
+		writel(pwm_value & ~BIT(pwm->hwpwm), ddata->base + REG_PWMSTART);
+}
+
+static void pwm_sg2044_set_outputenable(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
+					bool enabled)
+{
+	u32 pwm_value;
+
+	pwm_value = readl(ddata->base + REG_PWM_OE);
+
+	if (enabled)
+		writel(pwm_value | BIT(pwm->hwpwm), ddata->base + REG_PWM_OE);
+	else
+		writel(pwm_value & ~BIT(pwm->hwpwm), ddata->base + REG_PWM_OE);
+}
+
+static int pwm_sg2044_set_polarity(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
+				   const struct pwm_state *state)
+{
+	enum pwm_polarity polarity;
+	u32 pwm_value;
+
+	pwm_value = readl(ddata->base + REG_POLARITY);
+
+	polarity = state->polarity;
+
+	if (polarity == PWM_POLARITY_NORMAL)
+		pwm_value &= ~BIT(pwm->hwpwm);
+	else
+		pwm_value |= BIT(pwm->hwpwm);
+
+	writel(pwm_value, ddata->base + REG_POLARITY);
+
+	return 0;
+}
+
+static int pwm_sg2044_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
+	u32 hlperiod_ticks;
+	u32 period_ticks;
+
+	if (!state->enabled) {
+		pwm_sg2044_config(ddata, pwm, false);
+		return 0;
+	}
+
+	pwm_sg2044_set_polarity(ddata, pwm, state);
+
+	/*
+	 * Duration of High level (duty_cycle) = HLPERIOD x Period_of_input_clk
+	 * Duration of One Cycle (period) = PERIOD x Period_of_input_clk
+	 */
+	period_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->period,
+					       NSEC_PER_SEC), U32_MAX);
+	hlperiod_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->duty_cycle,
+						 NSEC_PER_SEC), U32_MAX);
+
+	dev_dbg(pwmchip_parent(chip), "chan[%u]: PERIOD=%u, HLPERIOD=%u\n",
+		pwm->hwpwm, period_ticks, hlperiod_ticks);
+
+	pwm_sg2042_config(ddata, pwm->hwpwm, period_ticks, hlperiod_ticks);
+
+	guard(mutex)(&ddata->lock);
+
+	/*
+	 * re-enable PWMSTART to refresh the register period
+	 */
+	pwm_sg2044_config(ddata, pwm, false);
+	pwm_sg2044_set_outputenable(ddata, pwm, true);
+	pwm_sg2044_config(ddata, pwm, true);
+
+	return 0;
+}
+
+static const struct sg2042_chip_data sg2042_chip_data = {
+	.ops = {
+		.apply = pwm_sg2042_apply,
+		.get_state = pwm_sg2042_get_state,
+	},
+	.atomic = true,
+};
+
+static const struct sg2042_chip_data sg2044_chip_data = {
+	.ops = {
+		.apply = pwm_sg2044_apply,
+		.get_state = pwm_sg2042_get_state,
+	},
+	.atomic = false,
 };

 static const struct of_device_id sg2042_pwm_ids[] = {
-	{ .compatible = "sophgo,sg2042-pwm" },
+	{ .compatible = "sophgo,sg2042-pwm",
+	  .data = &sg2042_chip_data },
+	{ .compatible = "sophgo,sg2044-pwm",
+	  .data = &sg2044_chip_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);
@@ -137,17 +244,24 @@ MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);
 static int pwm_sg2042_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	const struct sg2042_chip_data *chip_data;
 	struct sg2042_pwm_ddata *ddata;
 	struct reset_control *rst;
 	struct pwm_chip *chip;
 	struct clk *clk;
 	int ret;

+	chip_data = device_get_match_data(dev);
+	if (!chip_data)
+		return -ENODEV;
+
 	chip = devm_pwmchip_alloc(dev, SG2042_PWM_CHANNELNUM, sizeof(*ddata));
 	if (IS_ERR(chip))
 		return PTR_ERR(chip);
 	ddata = pwmchip_get_drvdata(chip);

+	mutex_init(&ddata->lock);
+
 	ddata->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(ddata->base))
 		return PTR_ERR(ddata->base);
@@ -170,8 +284,8 @@ static int pwm_sg2042_probe(struct platform_device *pdev)
 	if (IS_ERR(rst))
 		return dev_err_probe(dev, PTR_ERR(rst), "Failed to get reset\n");

-	chip->ops = &pwm_sg2042_ops;
-	chip->atomic = true;
+	chip->ops = &chip_data->ops;
+	chip->atomic = chip_data->atomic;

 	ret = devm_pwmchip_add(dev, chip);
 	if (ret < 0)
--
2.48.1

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