[RFC PATCH 2/2] drivers: pwm: pwm-atmel: add support for pwm modes

[Claudiu Beznea <claudiu.beznea@microchip.com>]

Implement pwm modes by adding PWM controller specific
configuration. Since this driver is used by controllers
which supports PWM push-pull mode and controllers which
doesn't, a new field was added in driver private data
structure. Also, the driver private data structure was
changed to adapt the new feature.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/pwm/pwm-atmel.c | 94 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 63 insertions(+), 31 deletions(-)

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 530d7dc..9e812ce 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -33,8 +33,11 @@
 
 #define PWM_CMR			0x0
 /* Bit field in CMR */
-#define PWM_CMR_CPOL		(1 << 9)
-#define PWM_CMR_UPD_CDTY	(1 << 10)
+#define PWM_CMR_CPOL		BIT(9)
+#define PWM_CMR_UPD_CDTY	BIT(10)
+#define PWM_CMR_DTHI		BIT(17)
+#define PWM_CMR_DTLI		BIT(18)
+#define PWM_CMR_PPM		BIT(19)
 #define PWM_CMR_CPRE_MSK	0xF
 
 /* The following registers for PWM v1 */
@@ -65,11 +68,16 @@ struct atmel_pwm_registers {
 	u8 duty_upd;
 };
 
+struct atmel_pwm_data {
+	struct atmel_pwm_registers regs;
+	bool ppm_supported;
+};
+
 struct atmel_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
 	void __iomem *base;
-	const struct atmel_pwm_registers *regs;
+	const struct atmel_pwm_data *data;
 
 	unsigned int updated_pwms;
 	/* ISR is cleared when read, ensure only one thread does that */
@@ -150,15 +158,15 @@ static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 	u32 val;
 
-	if (atmel_pwm->regs->duty_upd ==
-	    atmel_pwm->regs->period_upd) {
+	if (atmel_pwm->data->regs.duty_upd ==
+	    atmel_pwm->data->regs.period_upd) {
 		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
 		val &= ~PWM_CMR_UPD_CDTY;
 		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
 	}
 
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
-			    atmel_pwm->regs->duty_upd, cdty);
+			    atmel_pwm->data->regs.duty_upd, cdty);
 }
 
 static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
@@ -168,9 +176,9 @@ static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
 	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
 
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
-			    atmel_pwm->regs->duty, cdty);
+			    atmel_pwm->data->regs.duty, cdty);
 	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
-			    atmel_pwm->regs->period, cprd);
+			    atmel_pwm->data->regs.period, cprd);
 }
 
 static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -223,9 +231,10 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (state->enabled) {
 		if (cstate.enabled &&
 		    cstate.polarity == state->polarity &&
-		    cstate.period == state->period) {
+		    cstate.period == state->period &&
+		    cstate.mode == state->mode) {
 			cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
-						  atmel_pwm->regs->period);
+						  atmel_pwm->data->regs.period);
 			atmel_pwm_calculate_cdty(state, cprd, &cdty);
 			atmel_pwm_update_cdty(chip, pwm, cdty);
 			return 0;
@@ -258,6 +267,23 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			val &= ~PWM_CMR_CPOL;
 		else
 			val |= PWM_CMR_CPOL;
+
+		/* PWM mode. */
+		if (atmel_pwm->data->ppm_supported) {
+			if (state->mode == PWM_MODE_PUSH_PULL) {
+				val |= PWM_CMR_PPM;
+				if (state->polarity == PWM_POLARITY_NORMAL)
+					val = (val & ~PWM_CMR_DTHI) |
+					      PWM_CMR_DTLI;
+				else
+					val = (val & ~PWM_CMR_DTLI) |
+					      PWM_CMR_DTHI;
+			} else {
+				val &= ~(PWM_CMR_PPM | PWM_CMR_DTLI |
+					 PWM_CMR_DTHI);
+			}
+		}
+
 		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
 		atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty);
 		mutex_lock(&atmel_pwm->isr_lock);
@@ -277,27 +303,33 @@ static const struct pwm_ops atmel_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
-static const struct atmel_pwm_registers atmel_pwm_regs_v1 = {
-	.period		= PWMV1_CPRD,
-	.period_upd	= PWMV1_CUPD,
-	.duty		= PWMV1_CDTY,
-	.duty_upd	= PWMV1_CUPD,
+static const struct atmel_pwm_data atmel_pwm_data_v1 = {
+	.regs = {
+		.period		= PWMV1_CPRD,
+		.period_upd	= PWMV1_CUPD,
+		.duty		= PWMV1_CDTY,
+		.duty_upd	= PWMV1_CUPD,
+	},
+	.ppm_supported = false,
 };
 
-static const struct atmel_pwm_registers atmel_pwm_regs_v2 = {
-	.period		= PWMV2_CPRD,
-	.period_upd	= PWMV2_CPRDUPD,
-	.duty		= PWMV2_CDTY,
-	.duty_upd	= PWMV2_CDTYUPD,
+static const struct atmel_pwm_data atmel_pwm_data_v2 = {
+	.regs = {
+		.period		= PWMV2_CPRD,
+		.period_upd	= PWMV2_CPRDUPD,
+		.duty		= PWMV2_CDTY,
+		.duty_upd	= PWMV2_CDTYUPD,
+	},
+	.ppm_supported = true,
 };
 
 static const struct platform_device_id atmel_pwm_devtypes[] = {
 	{
 		.name = "at91sam9rl-pwm",
-		.driver_data = (kernel_ulong_t)&atmel_pwm_regs_v1,
+		.driver_data = (kernel_ulong_t)&atmel_pwm_data_v1,
 	}, {
 		.name = "sama5d3-pwm",
-		.driver_data = (kernel_ulong_t)&atmel_pwm_regs_v2,
+		.driver_data = (kernel_ulong_t)&atmel_pwm_data_v2,
 	}, {
 		/* sentinel */
 	},
@@ -307,20 +339,20 @@ MODULE_DEVICE_TABLE(platform, atmel_pwm_devtypes);
 static const struct of_device_id atmel_pwm_dt_ids[] = {
 	{
 		.compatible = "atmel,at91sam9rl-pwm",
-		.data = &atmel_pwm_regs_v1,
+		.data = &atmel_pwm_data_v1,
 	}, {
 		.compatible = "atmel,sama5d3-pwm",
-		.data = &atmel_pwm_regs_v2,
+		.data = &atmel_pwm_data_v2,
 	}, {
 		.compatible = "atmel,sama5d2-pwm",
-		.data = &atmel_pwm_regs_v2,
+		.data = &atmel_pwm_data_v2,
 	}, {
 		/* sentinel */
 	},
 };
 MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
 
-static inline const struct atmel_pwm_registers *
+static inline const struct atmel_pwm_data*
 atmel_pwm_get_driver_data(struct platform_device *pdev)
 {
 	const struct platform_device_id *id;
@@ -330,18 +362,18 @@ atmel_pwm_get_driver_data(struct platform_device *pdev)
 
 	id = platform_get_device_id(pdev);
 
-	return (struct atmel_pwm_registers *)id->driver_data;
+	return (struct atmel_pwm_data *)id->driver_data;
 }
 
 static int atmel_pwm_probe(struct platform_device *pdev)
 {
-	const struct atmel_pwm_registers *regs;
+	const struct atmel_pwm_data *data;
 	struct atmel_pwm_chip *atmel_pwm;
 	struct resource *res;
 	int ret;
 
-	regs = atmel_pwm_get_driver_data(pdev);
-	if (!regs)
+	data = atmel_pwm_get_driver_data(pdev);
+	if (!data)
 		return -ENODEV;
 
 	atmel_pwm = devm_kzalloc(&pdev->dev, sizeof(*atmel_pwm), GFP_KERNEL);
@@ -373,7 +405,7 @@ static int atmel_pwm_probe(struct platform_device *pdev)
 
 	atmel_pwm->chip.base = -1;
 	atmel_pwm->chip.npwm = 4;
-	atmel_pwm->regs = regs;
+	atmel_pwm->data = data;
 	atmel_pwm->updated_pwms = 0;
 	mutex_init(&atmel_pwm->isr_lock);
 
-- 
2.7.4