diff mbox

[[PATCH,v2] 09/11] pwm: sti: Add support for PWM Capture IRQs

Message ID 1461320295-20414-10-git-send-email-lee.jones@linaro.org
State Superseded
Headers show

Commit Message

Lee Jones April 22, 2016, 10:18 a.m. UTC
Here we're requesting the PWM Capture IRQ and supplying the
handler which will be called in the event of an IRQ fire to
handle it.

Signed-off-by: Lee Jones <lee.jones@linaro.org>

---
 drivers/pwm/pwm-sti.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 91 insertions(+), 1 deletion(-)

-- 
2.8.0

Comments

Peter Griffin June 7, 2016, 8:14 a.m. UTC | #1
Hi Lee,

On Fri, 22 Apr 2016, Lee Jones wrote:

> Here we're requesting the PWM Capture IRQ and supplying the

> handler which will be called in the event of an IRQ fire to

> handle it.

> 

> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> ---

>  drivers/pwm/pwm-sti.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++-

>  1 file changed, 91 insertions(+), 1 deletion(-)

> 

> diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c

> index 9d597bb..2230afb 100644

> --- a/drivers/pwm/pwm-sti.c

> +++ b/drivers/pwm/pwm-sti.c

> @@ -91,7 +91,9 @@ struct sti_pwm_chip {

>  	struct regmap_field *prescale_low;

>  	struct regmap_field *prescale_high;

>  	struct regmap_field *pwm_out_en;

> +	struct regmap_field *pwm_cpt_en;

>  	struct regmap_field *pwm_cpt_int_en;

> +	struct regmap_field *pwm_cpt_int_stat;

>  	struct pwm_chip chip;

>  	struct pwm_device *cur;

>  	unsigned long configured;

> @@ -311,6 +313,76 @@ static const struct pwm_ops sti_pwm_ops = {

>  	.owner = THIS_MODULE,

>  };

>  

> +static irqreturn_t sti_pwm_interrupt(int irq, void *data)

> +{

> +	struct sti_pwm_chip *pc = data;

> +	struct device *dev = pc->dev;

> +	struct sti_cpt_ddata *ddata;

> +	int devicenum;

> +	unsigned int cpt_int_stat;

> +	unsigned int reg;

> +	int ret = IRQ_NONE;

> +

> +	ret = regmap_field_read(pc->pwm_cpt_int_stat, &cpt_int_stat);

> +	if (ret)

> +		return ret;

> +

> +	while (cpt_int_stat) {

> +		devicenum = ffs(cpt_int_stat) - 1;

> +

> +		ddata = pwm_get_chip_data(&pc->chip.pwms[devicenum]);

> +

> +		/*

> +		 * Capture input:

> +		 *    _______                   _______

> +		 *   |       |                 |       |

> +		 * __|       |_________________|       |________

> +		 *   ^0      ^1                ^2

> +		 *

> +		 * Capture start by the first available rising edge

> +		 * When a capture event occurs, capture value (CPT_VALx)

> +		 * is stored, index incremented, capture edge changed.

> +		 *

> +		 * After the capture, if the index > 1, we have collected

> +		 * the necessary data so we signal the thread waiting for it

> +		 * and disable the capture by setting capture edge to none

> +		 *

> +		 */

> +

> +		regmap_read(pc->regmap,

> +			    PWM_CPT_VAL(devicenum),

> +			    &ddata->snapshot[ddata->index]);

> +

> +		switch (ddata->index) {

> +		case 0:

> +		case 1:

> +			regmap_read(pc->regmap, PWM_CPT_EDGE(devicenum), &reg);

> +			reg ^= PWM_CPT_EDGE_MASK;

> +			regmap_write(pc->regmap, PWM_CPT_EDGE(devicenum), reg);

> +

> +			ddata->index++;

> +			break;

> +		case 2:

> +			regmap_write(pc->regmap,

> +				     PWM_CPT_EDGE(devicenum),

> +				     CPT_EDGE_DISABLED);

> +			wake_up(&ddata->wait);

> +			break;

> +		default:

> +			dev_err(dev, "Internal error\n");

> +		}

> +

> +		cpt_int_stat &= ~BIT_MASK(devicenum);

> +

> +		ret = IRQ_HANDLED;

> +	}

> +

> +	/* Just ACK everything */

> +	regmap_write(pc->regmap, PWM_INT_ACK, PWM_INT_ACK_MASK);

> +

> +	return ret;

> +}

> +

>  static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)

>  {

>  	struct device *dev = pc->dev;

> @@ -351,6 +423,11 @@ static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)

>  	if (IS_ERR(pc->pwm_cpt_int_en))

>  		return PTR_ERR(pc->pwm_cpt_int_en);

>  

> +	pc->pwm_cpt_int_stat = devm_regmap_field_alloc(dev, pc->regmap,

> +						reg_fields[PWM_CPT_INT_STAT]);

> +	if (PTR_ERR_OR_ZERO(pc->pwm_cpt_int_stat))

> +		return PTR_ERR(pc->pwm_cpt_int_stat);

> +

>  	return 0;

>  }

>  

> @@ -367,7 +444,7 @@ static int sti_pwm_probe(struct platform_device *pdev)

>  	struct sti_pwm_chip *pc;

>  	struct resource *res;

>  	unsigned int devnum;

> -	int ret;

> +	int irq, ret;

>  

>  	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);

>  	if (!pc)

> @@ -388,6 +465,19 @@ static int sti_pwm_probe(struct platform_device *pdev)

>  	if (IS_ERR(pc->regmap))

>  		return PTR_ERR(pc->regmap);

>  

> +	irq = platform_get_irq(pdev, 0);

> +	if (irq < 0) {

> +		dev_err(&pdev->dev, "Failed to obtain IRQ\n");

> +		return irq;

> +	}

> +

> +	ret = devm_request_irq(&pdev->dev, irq, sti_pwm_interrupt,

> +			       0, pdev->name, pc);

> +	if (ret < 0) {

> +		dev_err(&pdev->dev, "Failed to request IRQ\n");

> +		return ret;

> +	}

> +

>  	/*

>  	 * Setup PWM data with default values: some values could be replaced

>  	 * with specific ones provided from Device Tree.


pwm-st.txt dt binding document and pwm example needs updating to document this
irq.

regards,

Peter
Lee Jones June 7, 2016, 9:03 a.m. UTC | #2
On Tue, 07 Jun 2016, Peter Griffin wrote:

> Hi Lee,

> 

> On Fri, 22 Apr 2016, Lee Jones wrote:

> 

> > Here we're requesting the PWM Capture IRQ and supplying the

> > handler which will be called in the event of an IRQ fire to

> > handle it.

> > 

> > Signed-off-by: Lee Jones <lee.jones@linaro.org>

> > ---

> >  drivers/pwm/pwm-sti.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++-

> >  1 file changed, 91 insertions(+), 1 deletion(-)

> > 

> > diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c

> > index 9d597bb..2230afb 100644

> > --- a/drivers/pwm/pwm-sti.c

> > +++ b/drivers/pwm/pwm-sti.c


[...]

Please cut any large chunks of unnecessary cruft when reviewing.

> > @@ -367,7 +444,7 @@ static int sti_pwm_probe(struct platform_device *pdev)

> >  	struct sti_pwm_chip *pc;

> >  	struct resource *res;

> >  	unsigned int devnum;

> > -	int ret;

> > +	int irq, ret;

> >  

> >  	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);

> >  	if (!pc)

> > @@ -388,6 +465,19 @@ static int sti_pwm_probe(struct platform_device *pdev)

> >  	if (IS_ERR(pc->regmap))

> >  		return PTR_ERR(pc->regmap);

> >  

> > +	irq = platform_get_irq(pdev, 0);

> > +	if (irq < 0) {

> > +		dev_err(&pdev->dev, "Failed to obtain IRQ\n");

> > +		return irq;

> > +	}

> > +

> > +	ret = devm_request_irq(&pdev->dev, irq, sti_pwm_interrupt,

> > +			       0, pdev->name, pc);

> > +	if (ret < 0) {

> > +		dev_err(&pdev->dev, "Failed to request IRQ\n");

> > +		return ret;

> > +	}

> > +

> >  	/*

> >  	 * Setup PWM data with default values: some values could be replaced

> >  	 * with specific ones provided from Device Tree.

> 

> pwm-st.txt dt binding document and pwm example needs updating to document this

> irq.


Yes, it does.  I will update the documentation and place it into this
patch-set on next submission. 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
diff mbox

Patch

diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c
index 9d597bb..2230afb 100644
--- a/drivers/pwm/pwm-sti.c
+++ b/drivers/pwm/pwm-sti.c
@@ -91,7 +91,9 @@  struct sti_pwm_chip {
 	struct regmap_field *prescale_low;
 	struct regmap_field *prescale_high;
 	struct regmap_field *pwm_out_en;
+	struct regmap_field *pwm_cpt_en;
 	struct regmap_field *pwm_cpt_int_en;
+	struct regmap_field *pwm_cpt_int_stat;
 	struct pwm_chip chip;
 	struct pwm_device *cur;
 	unsigned long configured;
@@ -311,6 +313,76 @@  static const struct pwm_ops sti_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
+static irqreturn_t sti_pwm_interrupt(int irq, void *data)
+{
+	struct sti_pwm_chip *pc = data;
+	struct device *dev = pc->dev;
+	struct sti_cpt_ddata *ddata;
+	int devicenum;
+	unsigned int cpt_int_stat;
+	unsigned int reg;
+	int ret = IRQ_NONE;
+
+	ret = regmap_field_read(pc->pwm_cpt_int_stat, &cpt_int_stat);
+	if (ret)
+		return ret;
+
+	while (cpt_int_stat) {
+		devicenum = ffs(cpt_int_stat) - 1;
+
+		ddata = pwm_get_chip_data(&pc->chip.pwms[devicenum]);
+
+		/*
+		 * Capture input:
+		 *    _______                   _______
+		 *   |       |                 |       |
+		 * __|       |_________________|       |________
+		 *   ^0      ^1                ^2
+		 *
+		 * Capture start by the first available rising edge
+		 * When a capture event occurs, capture value (CPT_VALx)
+		 * is stored, index incremented, capture edge changed.
+		 *
+		 * After the capture, if the index > 1, we have collected
+		 * the necessary data so we signal the thread waiting for it
+		 * and disable the capture by setting capture edge to none
+		 *
+		 */
+
+		regmap_read(pc->regmap,
+			    PWM_CPT_VAL(devicenum),
+			    &ddata->snapshot[ddata->index]);
+
+		switch (ddata->index) {
+		case 0:
+		case 1:
+			regmap_read(pc->regmap, PWM_CPT_EDGE(devicenum), &reg);
+			reg ^= PWM_CPT_EDGE_MASK;
+			regmap_write(pc->regmap, PWM_CPT_EDGE(devicenum), reg);
+
+			ddata->index++;
+			break;
+		case 2:
+			regmap_write(pc->regmap,
+				     PWM_CPT_EDGE(devicenum),
+				     CPT_EDGE_DISABLED);
+			wake_up(&ddata->wait);
+			break;
+		default:
+			dev_err(dev, "Internal error\n");
+		}
+
+		cpt_int_stat &= ~BIT_MASK(devicenum);
+
+		ret = IRQ_HANDLED;
+	}
+
+	/* Just ACK everything */
+	regmap_write(pc->regmap, PWM_INT_ACK, PWM_INT_ACK_MASK);
+
+	return ret;
+}
+
 static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
 {
 	struct device *dev = pc->dev;
@@ -351,6 +423,11 @@  static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
 	if (IS_ERR(pc->pwm_cpt_int_en))
 		return PTR_ERR(pc->pwm_cpt_int_en);
 
+	pc->pwm_cpt_int_stat = devm_regmap_field_alloc(dev, pc->regmap,
+						reg_fields[PWM_CPT_INT_STAT]);
+	if (PTR_ERR_OR_ZERO(pc->pwm_cpt_int_stat))
+		return PTR_ERR(pc->pwm_cpt_int_stat);
+
 	return 0;
 }
 
@@ -367,7 +444,7 @@  static int sti_pwm_probe(struct platform_device *pdev)
 	struct sti_pwm_chip *pc;
 	struct resource *res;
 	unsigned int devnum;
-	int ret;
+	int irq, ret;
 
 	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc)
@@ -388,6 +465,19 @@  static int sti_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pc->regmap))
 		return PTR_ERR(pc->regmap);
 
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Failed to obtain IRQ\n");
+		return irq;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, sti_pwm_interrupt,
+			       0, pdev->name, pc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to request IRQ\n");
+		return ret;
+	}
+
 	/*
 	 * Setup PWM data with default values: some values could be replaced
 	 * with specific ones provided from Device Tree.