[PATCH v2 0/2] LOW power sleep support for TI PWM submodules

[PATCH v2 0/2] LOW power sleep support for TI PWM submodules

[Philip Avinash]

TI PWM sub modules like ECAP & EHRPWM can enter in low power sleep
state during low power transitions of the platforms (like in AM33XX).
This patch series support low power sleep transition support. This
patch series depend on [1] and [2] and tested for low sleep support
on AM335x-evm for ECAP based PWM backlight.

1. ARM: OMAP2+: AM33XX: Add suspend-resume support
   http://www.mail-archive.com/linux-omap@vger.kernel.org/msg82635.html
2. HWMOD fixes for AM33xx PWM submodules and device tree nodes.
   https://lkml.org/lkml/2013/1/2/87

Philip Avinash (2):
  pwm: pwm-tiehrpwm: Low power sleep support
  pwm: pwm-tiecap: Low power sleep support

 drivers/pwm/pwm-tiecap.c   |   53 ++++++++++++++++++++++++++++
 drivers/pwm/pwm-tiehrpwm.c |   83 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+)

-- 
1.7.9.5

[PATCH v2 1/2] pwm: pwm-tiehrpwm: Low power sleep support

[Philip Avinash]

In low power modes of AM33XX platforms, peripherals power is cut off.
This patch supports low power sleep transition support for EHRPWM
driver.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
---
Changes since v1:
	- check the enabled status of pwm device for handling module
	  enable/disable on resume/suspend

 drivers/pwm/pwm-tiehrpwm.c |   83 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 4058df4..6627f42 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -113,6 +113,17 @@
 
 #define NUM_PWM_CHANNEL		2	/* EHRPWM channels */
 
+struct ehrpwm_context {
+	u16 tbctl;
+	u16 tbprd;
+	u16 cmpa;
+	u16 cmpb;
+	u16 aqctla;
+	u16 aqctlb;
+	u16 aqsfrc;
+	u16 aqcsfrc;
+};
+
 struct ehrpwm_pwm_chip {
 	struct pwm_chip	chip;
 	unsigned int	clk_rate;
@@ -120,6 +131,7 @@ struct ehrpwm_pwm_chip {
 	unsigned long period_cycles[NUM_PWM_CHANNEL];
 	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
 	struct	clk	*tbclk;
+	struct ehrpwm_context ctx;
 };
 
 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
@@ -127,6 +139,11 @@ static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
 	return container_of(chip, struct ehrpwm_pwm_chip, chip);
 }
 
+static u16 ehrpwm_read(void *base, int offset)
+{
+	return readw(base + offset);
+}
+
 static void ehrpwm_write(void *base, int offset, unsigned int val)
 {
 	writew(val & 0xFFFF, base + offset);
@@ -516,11 +533,77 @@ static int ehrpwm_pwm_remove(struct platform_device *pdev)
 	return pwmchip_remove(&pc->chip);
 }
 
+void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
+{
+	pm_runtime_get_sync(pc->chip.dev);
+	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
+	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
+	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
+	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
+	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
+	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
+	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
+	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
+	pm_runtime_put_sync(pc->chip.dev);
+}
+
+void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
+{
+	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
+	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
+	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
+	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
+	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
+	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
+	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
+	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
+}
+
+static int ehrpwm_pwm_suspend(struct device *dev)
+{
+	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
+	int i;
+
+	ehrpwm_pwm_save_context(pc);
+	for (i = 0; i < pc->chip.npwm; i++) {
+		struct pwm_device *pwm = &pc->chip.pwms[i];
+
+		if (!test_bit(PWMF_ENABLED, &pwm->flags))
+			continue;
+
+		/* Disable explicitly if PWM is running */
+		pm_runtime_put_sync(dev);
+	}
+	return 0;
+}
+
+static int ehrpwm_pwm_resume(struct device *dev)
+{
+	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
+	int i;
+
+	for (i = 0; i < pc->chip.npwm; i++) {
+		struct pwm_device *pwm = &pc->chip.pwms[i];
+
+		if (!test_bit(PWMF_ENABLED, &pwm->flags))
+			continue;
+
+		/* Enable explicitly if PWM was running */
+		pm_runtime_get_sync(dev);
+	}
+	ehrpwm_pwm_restore_context(pc);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
+		ehrpwm_pwm_resume);
+
 static struct platform_driver ehrpwm_pwm_driver = {
 	.driver = {
 		.name	= "ehrpwm",
 		.owner	= THIS_MODULE,
 		.of_match_table = ehrpwm_of_match,
+		.pm	= &ehrpwm_pwm_pm_ops,
 	},
 	.probe = ehrpwm_pwm_probe,
 	.remove = ehrpwm_pwm_remove,
-- 
1.7.9.5

[PATCH v2 2/2] pwm: pwm-tiecap: Low power sleep support

[Philip Avinash]

In low power modes of AM33XX platforms, peripherals power is cut off.
This patch supports low power sleep transition support for ECAP driver.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
---
Changes since v1:
	- check the enabled status of pwm device for handling module
	  enable/disable on resume/suspend

 drivers/pwm/pwm-tiecap.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 5cf016d..05b676d 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -41,10 +41,17 @@
 #define ECCTL2_SYNC_SEL_DISA	(BIT(7) | BIT(6))
 #define ECCTL2_TSCTR_FREERUN	BIT(4)
 
+struct ecap_context {
+	u32	cap3;
+	u32	cap4;
+	u16	ecctl2;
+};
+
 struct ecap_pwm_chip {
 	struct pwm_chip	chip;
 	unsigned int	clk_rate;
 	void __iomem	*mmio_base;
+	struct ecap_context ctx;
 };
 
 static inline struct ecap_pwm_chip *to_ecap_pwm_chip(struct pwm_chip *chip)
@@ -288,11 +295,57 @@ static int ecap_pwm_remove(struct platform_device *pdev)
 	return pwmchip_remove(&pc->chip);
 }
 
+void ecap_pwm_save_context(struct ecap_pwm_chip *pc)
+{
+	pm_runtime_get_sync(pc->chip.dev);
+	pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2);
+	pc->ctx.cap4 = readl(pc->mmio_base + CAP4);
+	pc->ctx.cap3 = readl(pc->mmio_base + CAP3);
+	pm_runtime_put_sync(pc->chip.dev);
+}
+
+void ecap_pwm_restore_context(struct ecap_pwm_chip *pc)
+{
+	writel(pc->ctx.cap3, pc->mmio_base + CAP3);
+	writel(pc->ctx.cap4, pc->mmio_base + CAP4);
+	writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2);
+}
+
+static int ecap_pwm_suspend(struct device *dev)
+{
+	struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
+	struct pwm_device *pwm = pc->chip.pwms;
+
+	ecap_pwm_save_context(pc);
+
+	/* Disable explicitly if PWM is running */
+	if (test_bit(PWMF_ENABLED, &pwm->flags))
+		pm_runtime_put_sync(dev);
+
+	return 0;
+}
+
+static int ecap_pwm_resume(struct device *dev)
+{
+	struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
+	struct pwm_device *pwm = pc->chip.pwms;
+
+	/* Enable explicitly if PWM was running */
+	if (test_bit(PWMF_ENABLED, &pwm->flags))
+		pm_runtime_get_sync(dev);
+
+	ecap_pwm_restore_context(pc);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ecap_pwm_pm_ops, ecap_pwm_suspend, ecap_pwm_resume);
+
 static struct platform_driver ecap_pwm_driver = {
 	.driver = {
 		.name	= "ecap",
 		.owner	= THIS_MODULE,
 		.of_match_table = ecap_of_match,
+		.pm	= &ecap_pwm_pm_ops,
 	},
 	.probe = ecap_pwm_probe,
 	.remove = ecap_pwm_remove,
-- 
1.7.9.5

Re: [PATCH v2 1/2] pwm: pwm-tiehrpwm: Low power sleep support

[Thierry Reding]

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On Thu, Jan 17, 2013 at 02:50:02PM +0530, Philip Avinash wrote:
> In low power modes of AM33XX platforms, peripherals power is cut off.
> This patch supports low power sleep transition support for EHRPWM
> driver.
> 
> Signed-off-by: Philip Avinash <avinashphilip@ti.com>
> ---
> Changes since v1:
> 	- check the enabled status of pwm device for handling module
> 	  enable/disable on resume/suspend
> 
>  drivers/pwm/pwm-tiehrpwm.c |   83 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 83 insertions(+)

Applied, thanks.

Thierry

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Re: [PATCH v2 2/2] pwm: pwm-tiecap: Low power sleep support

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 560 bytes --]

On Thu, Jan 17, 2013 at 02:50:03PM +0530, Philip Avinash wrote:
> In low power modes of AM33XX platforms, peripherals power is cut off.
> This patch supports low power sleep transition support for ECAP driver.
> 
> Signed-off-by: Philip Avinash <avinashphilip@ti.com>
> ---
> Changes since v1:
> 	- check the enabled status of pwm device for handling module
> 	  enable/disable on resume/suspend
> 
>  drivers/pwm/pwm-tiecap.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)

Applied, thanks.

Thierry

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RE: [PATCH v2 1/2] pwm: pwm-tiehrpwm: Low power sleep support

[Philip, Avinash]

On Thu, Jan 17, 2013 at 21:29:04, Thierry Reding wrote:
> On Thu, Jan 17, 2013 at 02:50:02PM +0530, Philip Avinash wrote:
> > In low power modes of AM33XX platforms, peripherals power is cut off.
> > This patch supports low power sleep transition support for EHRPWM
> > driver.
> > 
> > Signed-off-by: Philip Avinash <avinashphilip@ti.com>
> > ---
> > Changes since v1:
> > 	- check the enabled status of pwm device for handling module
> > 	  enable/disable on resume/suspend
> > 
> >  drivers/pwm/pwm-tiehrpwm.c |   83 ++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 83 insertions(+)
> 
> Applied, thanks.

Thanks for applying this patch
Avinash

> 
> Thierry
> 

RE: [PATCH v2 2/2] pwm: pwm-tiecap: Low power sleep support

[Philip, Avinash]

On Thu, Jan 17, 2013 at 21:29:14, Thierry Reding wrote:
> On Thu, Jan 17, 2013 at 02:50:03PM +0530, Philip Avinash wrote:
> > In low power modes of AM33XX platforms, peripherals power is cut off.
> > This patch supports low power sleep transition support for ECAP driver.
> > 
> > Signed-off-by: Philip Avinash <avinashphilip@ti.com>
> > ---
> > Changes since v1:
> > 	- check the enabled status of pwm device for handling module
> > 	  enable/disable on resume/suspend
> > 
> >  drivers/pwm/pwm-tiecap.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 53 insertions(+)
> 
> Applied, thanks.

Thanks for applying this patch
Avinash

> 
> Thierry
>