[PATCH V2 0/2] Support for configuring polarity of PWM

[PATCH V2 0/2] Support for configuring polarity of PWM

[Philip, Avinash]

These patch set adds support for configuring polarity of eCAP & eHRPWM.

Philip, Avinash (2):
  pwm: pwm-tiecap: Add support for configuring polarity of PWM
  pwm: pwm-tiehrpwm: Add support for configuring polarity of PWM

 drivers/pwm/pwm-tiecap.c   |   22 +++++++++++++
 drivers/pwm/pwm-tiehrpwm.c |   72 +++++++++++++++++++++++++++++++-------------
 2 files changed, 73 insertions(+), 21 deletions(-)

[PATCH V2 1/2] pwm: pwm-tiecap: Add support for configuring polarity of PWM

[Philip, Avinash]

ECAP APWM hardware supports polarity configuration of PWM output.
This commit adds support for polarity configuration of ECAP APWM.

Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
---
:100644 100644 4b66889... a3d21e7... M	drivers/pwm/pwm-tiecap.c
 drivers/pwm/pwm-tiecap.c |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 4b66889..a3d21e7 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -32,6 +32,7 @@
 #define CAP3			0x10
 #define CAP4			0x14
 #define ECCTL2			0x2A
+#define ECCTL2_APWM_POL_LOW	BIT(10)
 #define ECCTL2_APWM_MODE	BIT(9)
 #define ECCTL2_SYNC_SEL_DISA	(BIT(7) | BIT(6))
 #define ECCTL2_TSCTR_FREERUN	BIT(4)
@@ -111,6 +112,26 @@ static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	return 0;
 }
 
+static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+		enum pwm_polarity polarity)
+{
+	struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+	unsigned short reg_val;
+
+	pm_runtime_get_sync(pc->chip.dev);
+	reg_val = readw(pc->mmio_base + ECCTL2);
+	if (polarity == PWM_POLARITY_INVERSED)
+		/* Duty cycle defines LOW period of PWM */
+		reg_val |= ECCTL2_APWM_POL_LOW;
+	else
+		/* Duty cycle defines HIGH period of PWM */
+		reg_val &= ~ECCTL2_APWM_POL_LOW;
+
+	writew(reg_val, pc->mmio_base + ECCTL2);
+	pm_runtime_put_sync(pc->chip.dev);
+	return 0;
+}
+
 static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
@@ -157,6 +178,7 @@ static void ecap_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 static const struct pwm_ops ecap_pwm_ops = {
 	.free		= ecap_pwm_free,
 	.config		= ecap_pwm_config,
+	.set_polarity	= ecap_pwm_set_polarity,
 	.enable		= ecap_pwm_enable,
 	.disable	= ecap_pwm_disable,
 	.owner		= THIS_MODULE,
-- 
1.7.1

[PATCH V2 2/2] pwm: pwm-tiehrpwm: Add support for configuring polarity of PWM

[Philip, Avinash]

EHRPWM hardware supports polarity configuration of PWM output. However
configuration of polarity done in hardware only in .enable() to ensure
PWM output present only after enabling PWM. This commit adds support for
polarity configuration for EHRPWM.
When being here, remove configuring of polarity during .config() and do
it explicitly from .set_polarity().

Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
---
changes since v1:
	- Remove config_chans API. Duty cycle configuration done in .cinfig()
	- Introduce config_polarity API, as don't want to confuse the
	  functionality of .enable()
	- Introduce polarity member as array in private structure to handle
	  both channels.

:100644 100644 b1996bc... db3675f... M	drivers/pwm/pwm-tiehrpwm.c
 drivers/pwm/pwm-tiehrpwm.c |   73 ++++++++++++++++++++++++++++++-------------
 1 files changed, 51 insertions(+), 22 deletions(-)

diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index b1996bc..db3675f 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -81,6 +81,15 @@
 #define AQCTL_ZRO_FRCHIGH	BIT(1)
 #define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))
 
+#define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
+				AQCTL_ZRO_FRCHIGH)
+#define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
+				AQCTL_ZRO_FRCLOW)
+#define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
+				AQCTL_ZRO_FRCHIGH)
+#define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
+				AQCTL_ZRO_FRCLOW)
+
 #define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
 #define AQSFRC_RLDCSF_ZRO	0
 #define AQSFRC_RLDCSF_PRD	BIT(6)
@@ -105,6 +114,7 @@ struct ehrpwm_pwm_chip {
 	unsigned int	clk_rate;
 	void __iomem	*mmio_base;
 	unsigned long period_cycles[NUM_PWM_CHANNEL];
+	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
 };
 
 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
@@ -165,39 +175,37 @@ static int set_prescale_div(unsigned long rqst_prescaler,
 	return 1;
 }
 
-static void configure_chans(struct ehrpwm_pwm_chip *pc, int chan,
-		unsigned long duty_cycles)
+static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
 {
-	int cmp_reg, aqctl_reg;
+	int aqctl_reg;
 	unsigned short aqctl_val, aqctl_mask;
 
 	/*
-	 * Channels can be configured from action qualifier module.
-	 * Channel 0 configured with compare A register and for
-	 * up-counter mode.
-	 * Channel 1 configured with compare B register and for
-	 * up-counter mode.
+	 * Configure PWM output to HIGH/LOW level on counter
+	 * reaches compare register value and LOW/HIGH level
+	 * on counter value reaches period register value and
+	 * zero value on counter
 	 */
 	if (chan == 1) {
 		aqctl_reg = AQCTLB;
-		cmp_reg = CMPB;
-		/* Configure PWM Low from compare B value */
-		aqctl_val = AQCTL_CBU_FRCLOW;
 		aqctl_mask = AQCTL_CBU_MASK;
+
+		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
+			aqctl_val = AQCTL_CHANB_POLINVERSED;
+		else
+			aqctl_val = AQCTL_CHANB_POLNORMAL;
 	} else {
-		cmp_reg = CMPA;
 		aqctl_reg = AQCTLA;
-		/* Configure PWM Low from compare A value*/
-		aqctl_val = AQCTL_CAU_FRCLOW;
 		aqctl_mask = AQCTL_CAU_MASK;
+
+		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
+			aqctl_val = AQCTL_CHANA_POLINVERSED;
+		else
+			aqctl_val = AQCTL_CHANA_POLNORMAL;
 	}
 
-	/* Configure PWM High from period value and zero value */
-	aqctl_val |= AQCTL_PRD_FRCHIGH | AQCTL_ZRO_FRCHIGH;
 	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
-	ehrpwm_modify(pc->mmio_base,  aqctl_reg, aqctl_mask, aqctl_val);
-
-	ehrpwm_write(pc->mmio_base,  cmp_reg, duty_cycles);
+	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
 }
 
 /*
@@ -211,7 +219,7 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned long long c;
 	unsigned long period_cycles, duty_cycles;
 	unsigned short ps_divval, tb_divval;
-	int i;
+	int i, cmp_reg;
 
 	if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
 		return -ERANGE;
@@ -278,12 +286,29 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
 			TBCTL_CTRMODE_UP);
 
-	/* Configure the channel for duty cycle */
-	configure_chans(pc, pwm->hwpwm, duty_cycles);
+	if (pwm->hwpwm == 1)
+		/* Channel 1 configured with compare B register */
+		cmp_reg = CMPB;
+	else
+		/* Channel 0 configured with compare A register */
+		cmp_reg = CMPA;
+
+	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
+
 	pm_runtime_put_sync(chip->dev);
 	return 0;
 }
 
+static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
+		struct pwm_device *pwm,	enum pwm_polarity polarity)
+{
+	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
+
+	/* Configuration of polarity in hardware delayed, do at enable */
+	pc->polarity[pwm->hwpwm] = polarity;
+	return 0;
+}
+
 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
@@ -307,6 +332,9 @@ static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
 
+	/* Channels polarity can be configured from action qualifier module */
+	configure_polarity(pc, pwm->hwpwm);
+
 	/* Enable time counter for free_run */
 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
 	return 0;
@@ -358,6 +386,7 @@ static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 static const struct pwm_ops ehrpwm_pwm_ops = {
 	.free		= ehrpwm_pwm_free,
 	.config		= ehrpwm_pwm_config,
+	.set_polarity	= ehrpwm_pwm_set_polarity,
 	.enable		= ehrpwm_pwm_enable,
 	.disable	= ehrpwm_pwm_disable,
 	.owner		= THIS_MODULE,
-- 
1.7.1

Re: [PATCH V2 0/2] Support for configuring polarity of PWM

[Thierry Reding]

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On Thu, Sep 06, 2012 at 10:40:01AM +0530, Philip, Avinash wrote:
> These patch set adds support for configuring polarity of eCAP & eHRPWM.
> 
> Philip, Avinash (2):
>   pwm: pwm-tiecap: Add support for configuring polarity of PWM
>   pwm: pwm-tiehrpwm: Add support for configuring polarity of PWM
> 
>  drivers/pwm/pwm-tiecap.c   |   22 +++++++++++++
>  drivers/pwm/pwm-tiehrpwm.c |   72 +++++++++++++++++++++++++++++++-------------
>  2 files changed, 73 insertions(+), 21 deletions(-)

Both patches applied, thanks.

Thierry

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