Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1569287 > unrolled thread

[PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX PWMv2

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX PWMv2 Lukasz Majewski <lukma@denx.de> - 2017-01-29 23:00 +0100
    Re: [PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX  PWMv2 Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-01-30 09:00 +0100
      Re: [PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX  PWMv2 Thierry Reding <thierry.reding@gmail.com> - 2017-01-30 09:10 +0100

#1569287 — [PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX PWMv2

This commit provides apply() callback implementation for i.MX's PWMv2.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
Changes for v5:
- Modify ->apply() function to avoid unbalanced clock enabling/disabling
- Fix preventing iMX7 from hanging

Changes for v4:
- Avoid recalculation of PWM parameters when disabling PWM signal
- Unconditionally call clk_prepare_enable(imx->clk_per) and
  clk_disable_unprepare(imx->clk_per)

Changes for v3:
- Remove ipg clock enable/disable functions

Changes for v2:
- None
---
 drivers/pwm/pwm-imx.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 60cdc5c..fdaa11b 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip,
 	return ret;
 }
 
+static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
+			    struct pwm_state *state)
+{
+	unsigned long period_cycles, duty_cycles, prescale;
+	struct imx_chip *imx = to_imx_chip(chip);
+	struct pwm_state cstate;
+	unsigned long long c;
+	int ret;
+
+	pwm_get_state(pwm, &cstate);
+
+	if (state->enabled) {
+		c = clk_get_rate(imx->clk_per);
+		c *= state->period;
+
+		do_div(c, 1000000000);
+		period_cycles = c;
+
+		prescale = period_cycles / 0x10000 + 1;
+
+		period_cycles /= prescale;
+		c = (unsigned long long)period_cycles * state->duty_cycle;
+		do_div(c, state->period);
+		duty_cycles = c;
+
+		/*
+		 * according to imx pwm RM, the real period value should be
+		 * PERIOD value in PWMPR plus 2.
+		 */
+		if (period_cycles > 2)
+			period_cycles -= 2;
+		else
+			period_cycles = 0;
+
+		/*
+		 * Wait for a free FIFO slot if the PWM is already enabled, and
+		 * flush the FIFO if the PWM was disabled and is about to be
+		 * enabled.
+		 */
+		if (cstate.enabled) {
+			imx_pwm_wait_fifo_slot(chip, pwm);
+		} else if (state->enabled) {
+			ret = clk_prepare_enable(imx->clk_per);
+			if (ret)
+				return ret;
+
+			imx_pwm_sw_reset(chip);
+		}
+
+		writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+		writel(period_cycles, imx->mmio_base + MX3_PWMPR);
+
+		writel(MX3_PWMCR_PRESCALER(prescale) |
+		       MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+		       MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
+		       MX3_PWMCR_EN,
+		       imx->mmio_base + MX3_PWMCR);
+
+	} else if (cstate.enabled) {
+		writel(0, imx->mmio_base + MX3_PWMCR);
+
+		clk_disable_unprepare(imx->clk_per);
+	}
+
+	return 0;
+}
+
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct imx_chip *imx = to_imx_chip(chip);
@@ -280,6 +347,7 @@ static struct pwm_ops imx_pwm_ops_v1 = {
 };
 
 static struct pwm_ops imx_pwm_ops_v2 = {
+	.apply = imx_pwm_apply_v2,
 	.enable = imx_pwm_enable,
 	.disable = imx_pwm_disable,
 	.config = imx_pwm_config,
-- 
2.1.4

[toc] | [next] | [standalone]

#1569447 — Re: [PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX PWMv2

On Sun, 29 Jan 2017 22:54:11 +0100
Lukasz Majewski <lukma@denx.de> wrote:

> This commit provides apply() callback implementation for i.MX's PWMv2.
> 
> Suggested-by: Stefan Agner <stefan@agner.ch>
> Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> Changes for v5:
> - Modify ->apply() function to avoid unbalanced clock enabling/disabling
> - Fix preventing iMX7 from hanging
> 
> Changes for v4:
> - Avoid recalculation of PWM parameters when disabling PWM signal
> - Unconditionally call clk_prepare_enable(imx->clk_per) and
>   clk_disable_unprepare(imx->clk_per)
> 
> Changes for v3:
> - Remove ipg clock enable/disable functions
> 
> Changes for v2:
> - None
> ---
>  drivers/pwm/pwm-imx.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
> index 60cdc5c..fdaa11b 100644
> --- a/drivers/pwm/pwm-imx.c
> +++ b/drivers/pwm/pwm-imx.c
> @@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip,
>  	return ret;
>  }
>  
> +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
> +			    struct pwm_state *state)
> +{
> +	unsigned long period_cycles, duty_cycles, prescale;
> +	struct imx_chip *imx = to_imx_chip(chip);
> +	struct pwm_state cstate;
> +	unsigned long long c;
> +	int ret;
> +
> +	pwm_get_state(pwm, &cstate);
> +
> +	if (state->enabled) {
> +		c = clk_get_rate(imx->clk_per);
> +		c *= state->period;
> +
> +		do_div(c, 1000000000);
> +		period_cycles = c;
> +
> +		prescale = period_cycles / 0x10000 + 1;
> +
> +		period_cycles /= prescale;
> +		c = (unsigned long long)period_cycles * state->duty_cycle;
> +		do_div(c, state->period);
> +		duty_cycles = c;
> +
> +		/*
> +		 * according to imx pwm RM, the real period value should be
> +		 * PERIOD value in PWMPR plus 2.
> +		 */
> +		if (period_cycles > 2)
> +			period_cycles -= 2;
> +		else
> +			period_cycles = 0;
> +
> +		/*
> +		 * Wait for a free FIFO slot if the PWM is already enabled, and
> +		 * flush the FIFO if the PWM was disabled and is about to be
> +		 * enabled.
> +		 */
> +		if (cstate.enabled) {
> +			imx_pwm_wait_fifo_slot(chip, pwm);
> +		} else if (state->enabled) {

Should just be

		} else {

since we're already in the 'if (state->enabled)' block (see above).

I see that Thierry already applied the series, so, just for the record,
with this fixed, the whole series is

Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Thanks,

Boris

> +			ret = clk_prepare_enable(imx->clk_per);
> +			if (ret)
> +				return ret;
> +
> +			imx_pwm_sw_reset(chip);
> +		}
> +
> +		writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
> +		writel(period_cycles, imx->mmio_base + MX3_PWMPR);
> +
> +		writel(MX3_PWMCR_PRESCALER(prescale) |
> +		       MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
> +		       MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
> +		       MX3_PWMCR_EN,
> +		       imx->mmio_base + MX3_PWMCR);
> +
> +	} else if (cstate.enabled) {
> +		writel(0, imx->mmio_base + MX3_PWMCR);
> +
> +		clk_disable_unprepare(imx->clk_per);
> +	}
> +
> +	return 0;
> +}

[toc] | [prev] | [next] | [standalone]

#1569452 — Re: [PATCH v5 07/11] pwm: imx: Provide atomic PWM support for i.MX PWMv2

[Multipart message — attachments visible in raw view] — view raw

On Mon, Jan 30, 2017 at 08:49:14AM +0100, Boris Brezillon wrote:
> On Sun, 29 Jan 2017 22:54:11 +0100
> Lukasz Majewski <lukma@denx.de> wrote:
> 
> > This commit provides apply() callback implementation for i.MX's PWMv2.
> > 
> > Suggested-by: Stefan Agner <stefan@agner.ch>
> > Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
> > Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > ---
> > Changes for v5:
> > - Modify ->apply() function to avoid unbalanced clock enabling/disabling
> > - Fix preventing iMX7 from hanging
> > 
> > Changes for v4:
> > - Avoid recalculation of PWM parameters when disabling PWM signal
> > - Unconditionally call clk_prepare_enable(imx->clk_per) and
> >   clk_disable_unprepare(imx->clk_per)
> > 
> > Changes for v3:
> > - Remove ipg clock enable/disable functions
> > 
> > Changes for v2:
> > - None
> > ---
> >  drivers/pwm/pwm-imx.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 68 insertions(+)
> > 
> > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
> > index 60cdc5c..fdaa11b 100644
> > --- a/drivers/pwm/pwm-imx.c
> > +++ b/drivers/pwm/pwm-imx.c
> > @@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip,
> >  	return ret;
> >  }
> >  
> > +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
> > +			    struct pwm_state *state)
> > +{
> > +	unsigned long period_cycles, duty_cycles, prescale;
> > +	struct imx_chip *imx = to_imx_chip(chip);
> > +	struct pwm_state cstate;
> > +	unsigned long long c;
> > +	int ret;
> > +
> > +	pwm_get_state(pwm, &cstate);
> > +
> > +	if (state->enabled) {
> > +		c = clk_get_rate(imx->clk_per);
> > +		c *= state->period;
> > +
> > +		do_div(c, 1000000000);
> > +		period_cycles = c;
> > +
> > +		prescale = period_cycles / 0x10000 + 1;
> > +
> > +		period_cycles /= prescale;
> > +		c = (unsigned long long)period_cycles * state->duty_cycle;
> > +		do_div(c, state->period);
> > +		duty_cycles = c;
> > +
> > +		/*
> > +		 * according to imx pwm RM, the real period value should be
> > +		 * PERIOD value in PWMPR plus 2.
> > +		 */
> > +		if (period_cycles > 2)
> > +			period_cycles -= 2;
> > +		else
> > +			period_cycles = 0;
> > +
> > +		/*
> > +		 * Wait for a free FIFO slot if the PWM is already enabled, and
> > +		 * flush the FIFO if the PWM was disabled and is about to be
> > +		 * enabled.
> > +		 */
> > +		if (cstate.enabled) {
> > +			imx_pwm_wait_fifo_slot(chip, pwm);
> > +		} else if (state->enabled) {
> 
> Should just be
> 
> 		} else {
> 
> since we're already in the 'if (state->enabled)' block (see above).
> 
> I see that Thierry already applied the series, so, just for the record,
> with this fixed, the whole series is
> 
> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

I haven't gotten to that patch yet because I need to manually apply a
bunch of these because of the const pwm_ops patch. I'll apply the change
you mentioned and will add your R-b tag.

Thanks,
Thierry

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web