[PATCH] Thermal: imx: add clk disable/enable for suspend/resume

[PATCH] Thermal: imx: add clk disable/enable for suspend/resume

[Anson Huang]

Thermal sensor's clk is from pll3_usb_otg, per hardware
design requirement, need to make sure pll3_usb_otg is disabled
before STOP mode is entered, otherwise, all PFDs under it may
enter incorrect state, this patch disables pll3_usb_otg before
suspend and enables it after resume.

Signed-off-by: Anson Huang <b20788@freescale.com>
---
 drivers/thermal/imx_thermal.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 461bf3d..03894da 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -600,6 +600,8 @@ static int imx_thermal_suspend(struct device *dev)
 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 	data->mode = THERMAL_DEVICE_DISABLED;
+	if (!IS_ERR(data->thermal_clk))
+		clk_disable_unprepare(data->thermal_clk);
 
 	return 0;
 }
@@ -609,6 +611,8 @@ static int imx_thermal_resume(struct device *dev)
 	struct imx_thermal_data *data = dev_get_drvdata(dev);
 	struct regmap *map = data->tempmon;
 
+	if (!IS_ERR(data->thermal_clk))
+		clk_prepare_enable(data->thermal_clk);
 	/* Enabled thermal sensor after resume */
 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
-- 
1.9.1

Re: [PATCH] Thermal: imx: add clk disable/enable for suspend/resume

[Eduardo Valentin]

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Hello,

On Mon, Jan 05, 2015 at 10:34:11PM +0530, Pankaj Jangra wrote:
> Hi Anson,
> 
> On Mon, Jan 5, 2015 at 7:59 PM, Anson Huang <b20788@freescale.com> wrote:
> 
> > Thermal sensor's clk is from pll3_usb_otg, per hardware
> > design requirement, need to make sure pll3_usb_otg is disabled
> > before STOP mode is entered, otherwise, all PFDs under it may
> > enter incorrect state, this patch disables pll3_usb_otg before
> > suspend and enables it after resume.
> >
> > Signed-off-by: Anson Huang <b20788@freescale.com>
> >
> > +++ b/drivers/thermal/imx_thermal.c
> > @@ -600,6 +600,8 @@ static int imx_thermal_suspend(struct device *dev)
> >         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
> >         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
> >         data->mode = THERMAL_DEVICE_DISABLED;
> > +       if (!IS_ERR(data->thermal_clk))
> >
> I think you do not need to check for the error condition here. Because
> during the probe of driver, this condition is already checked and if the
> clock get is failed,
> it will fail the driver probing itself.
> 

Agreed here, no need for this extra check.

> +               clk_disable_unprepare(data->thermal_clk);
> 
> 
> >         return 0;
> >  }
> > @@ -609,6 +611,8 @@ static int imx_thermal_resume(struct device *dev)
> >         struct imx_thermal_data *data = dev_get_drvdata(dev);
> >         struct regmap *map = data->tempmon;
> >
> > +       if (!IS_ERR(data->thermal_clk))
> >
> Same as above.
> 
> > +               clk_prepare_enable(data->thermal_clk);
> >         /* Enabled thermal sensor after resume */
> >         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
> >         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
> > --
> >
> 
> Else changes looks good to me.
> 
> -- Pankaj Jangra
> 
> > 1.9.1
> >
> > --
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> >

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