Re: [PATCH] Thermal: imx: add i.mx6sx thermal support

[Anson Huang <b20788@freescale.com>]

On Tue, Aug 05, 2014 at 09:25:53AM -0400, Eduardo Valentin wrote:
> Hello Anson,
> 
> On Tue, Aug 05, 2014 at 05:12:43PM +0800, Anson Huang wrote:
> > i.MX6SX has some new features of thermal interrupt function,
> > there are LOW, HIGH and PANIC irq for thermal sensor, so add
> > platform data to separate different thermal version;
> > 
> > The reset value of LOW ALARM is 0 which means the highest
> > temp, so the LOW ALARM will be triggered once irq is enabled,
> > so we need to correct it before enabling thermal irq;
> > 
> > Enable PANIC ALARM as critical trip point, it will trigger
> > system reset via SRC module once PANIC IRQ is triggered, it
> > is pure hardware function, so use it instead of software
> > reset by cooling device.
> > 
> > Signed-off-by: Anson Huang <b20788@freescale.com>
> > ---
> >  .../devicetree/bindings/thermal/imx-thermal.txt    |    2 +-
> >  drivers/thermal/imx_thermal.c                      |   88 +++++++++++++++++---
> >  2 files changed, 76 insertions(+), 14 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/thermal/imx-thermal.txt b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> > index 1f0f672..95c05b1 100644
> > --- a/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> > +++ b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> > @@ -1,7 +1,7 @@
> >  * Temperature Monitor (TEMPMON) on Freescale i.MX SoCs
> >  
> >  Required properties:
> > -- compatible : "fsl,imx6q-thermal"
> > +- compatible : "fsl,imx6q-tempmon" for V1, "fsl,imx6sx-tempmon" for V2.
> 
> It would be kind to document the difference between V1 and V2, don't you
> think?

Accepted, will add some brief summary about the new feature added on V2.

> 
> >  - fsl,tempmon : phandle pointer to system controller that contains TEMPMON
> >    control registers, e.g. ANATOP on imx6q.
> >  - fsl,tempmon-data : phandle pointer to fuse controller that contains TEMPMON
> > diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> > index 2c516f2..2276e74 100644
> > --- a/drivers/thermal/imx_thermal.c
> > +++ b/drivers/thermal/imx_thermal.c
> > @@ -19,6 +19,7 @@
> >  #include <linux/mfd/syscon.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> > +#include <linux/of_device.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/regmap.h>
> >  #include <linux/slab.h>
> > @@ -31,6 +32,10 @@
> >  
> >  #define MISC0				0x0150
> >  #define MISC0_REFTOP_SELBIASOFF		(1 << 3)
> > +#define MISC1				0x0160
> > +#define MISC1_IRQ_TEMPHIGH		(1 << 29)
> > +#define MISC1_IRQ_TEMPLOW		(1 << 28)
> > +#define MISC1_IRQ_TEMPPANIC		(1 << 27)
> 
> how about using 
> +#define MISC1_IRQ_TEMPHIGH		BIT(29)
> +#define MISC1_IRQ_TEMPLOW		BIT(28)
> +#define MISC1_IRQ_TEMPPANIC		BIT(27)
> 

Accepted, will improve it in V2 patch.

> >  
> >  #define TEMPSENSE0			0x0180
> >  #define TEMPSENSE0_ALARM_VALUE_SHIFT	20
> > @@ -43,6 +48,11 @@
> >  
> >  #define TEMPSENSE1			0x0190
> >  #define TEMPSENSE1_MEASURE_FREQ		0xffff
> > +#define TEMPSENSE2			0x0290
> > +#define TEMPSENSE2_LOW_VALUE_SHIFT	0
> > +#define TEMPSENSE2_LOW_VALUE_MASK	0xfff
> > +#define TEMPSENSE2_PANIC_VALUE_SHIFT	16
> > +#define TEMPSENSE2_PANIC_VALUE_MASK	0xfff0000
> 
> Are the above register offsets and (bit) masks applicable to both
> versions? do you mind adding a comment to what is specific to V2?
> 

Accepted, will add comments in V2 patch.

> >  
> >  #define OCOTP_ANA1			0x04e0
> >  
> > @@ -66,6 +76,21 @@ enum imx_thermal_trip {
> >  #define FACTOR1				15976
> >  #define FACTOR2				4297157
> >  
> > +#define TEMPMON_V1			1
> > +#define TEMPMON_V2			2
> > +
> 
> where does the V1/V2 nomenclature come from? how about:
> 
> +#define TEMPMON_IMX6Q			1
> +#define TEMPMON_IMX6SX			2
> 

OK.

> 
> > +struct thermal_soc_data {
> > +	u32 version;
> > +};
> > +
> > +static struct thermal_soc_data thermal_imx6q_data = {
> > +	.version = TEMPMON_V1,
> > +};
> > +
> > +static struct thermal_soc_data thermal_imx6sx_data = {
> > +	.version = TEMPMON_V2,
> > +};
> > +
> >  struct imx_thermal_data {
> >  	struct thermal_zone_device *tz;
> >  	struct thermal_cooling_device *cdev;
> > @@ -79,8 +104,21 @@ struct imx_thermal_data {
> >  	bool irq_enabled;
> >  	int irq;
> >  	struct clk *thermal_clk;
> > +	const struct thermal_soc_data *socdata;
> >  };
> >  
> > +static void imx_set_panic_temp(struct imx_thermal_data *data,
> > +			       signed long panic_temp)
> > +{
> > +	struct regmap *map = data->tempmon;
> > +	int critical_value;
> > +
> > +	critical_value = (data->c2 - panic_temp) / data->c1;
> > +	regmap_write(map, TEMPSENSE2 + REG_CLR, TEMPSENSE2_PANIC_VALUE_MASK);
> > +	regmap_write(map, TEMPSENSE2 + REG_SET, critical_value <<
> > +			TEMPSENSE2_PANIC_VALUE_SHIFT);
> > +}
> > +
> >  static void imx_set_alarm_temp(struct imx_thermal_data *data,
> >  			       signed long alarm_temp)
> >  {
> > @@ -142,13 +180,15 @@ static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
> >  	/* See imx_get_sensor_data() for formula derivation */
> >  	*temp = data->c2 - n_meas * data->c1;
> >  
> > -	/* Update alarm value to next higher trip point */
> > -	if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive)
> > -		imx_set_alarm_temp(data, data->temp_critical);
> > -	if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) {
> > -		imx_set_alarm_temp(data, data->temp_passive);
> > -		dev_dbg(&tz->device, "thermal alarm off: T < %lu\n",
> > -			data->alarm_temp / 1000);
> > +	/* Update alarm value to next higher trip point, only V1 needs it */
> > +	if (data->socdata->version == TEMPMON_V1) {
> > +		if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive)
> > +			imx_set_alarm_temp(data, data->temp_critical);
> > +		if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) {
> > +			imx_set_alarm_temp(data, data->temp_passive);
> > +			dev_dbg(&tz->device, "thermal alarm off: T < %lu\n",
> > +				data->alarm_temp / 1000);
> > +		}
> >  	}
> >  
> >  	if (*temp != data->last_temp) {
> > @@ -398,8 +438,17 @@ static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
> >  	return IRQ_HANDLED;
> >  }
> >  
> > +static const struct of_device_id of_imx_thermal_match[] = {
> > +	{ .compatible = "fsl,imx6q-tempmon", .data = &thermal_imx6q_data, },
> > +	{ .compatible = "fsl,imx6sx-tempmon", .data = &thermal_imx6sx_data, },
> > +	{ /* end */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
> > +
> >  static int imx_thermal_probe(struct platform_device *pdev)
> >  {
> > +	const struct of_device_id *of_id =
> > +		of_match_device(of_imx_thermal_match, &pdev->dev);
> >  	struct imx_thermal_data *data;
> >  	struct cpumask clip_cpus;
> >  	struct regmap *map;
> > @@ -418,6 +467,21 @@ static int imx_thermal_probe(struct platform_device *pdev)
> >  	}
> >  	data->tempmon = map;
> >  
> > +	data->socdata = of_id->data;
> > +
> > +	/* make sure the IRQ flag is clear before enable irq */
> > +	regmap_write(map, MISC1 + REG_CLR, MISC1_IRQ_TEMPHIGH);
> 
> Shouldn't this be also done only for TEMPMON_V2? What is the benefit /
> effect in doing for V1 ?
> 

As on i.MX6SX, these bits are set by default, so we must clear them here, since
the TEMPHIGH is common for all i.MX6 SoCs, so I do it for both V1 and V2. But I am
OK to move it to only for V2, as we did NOT meet any issue on V1 before. Will move
it in patch V2.

Thanks for review!

Anson

> > +	if (data->socdata->version == TEMPMON_V2) {
> > +		regmap_write(map, MISC1 + REG_CLR, MISC1_IRQ_TEMPLOW |
> > +			MISC1_IRQ_TEMPPANIC);
> > +		/*
> > +		 * reset value of LOW ALARM is incorrect, set it to lowest
> > +		 * value to avoid false trigger of low alarm.
> > +		 */
> > +		regmap_write(map, TEMPSENSE2 + REG_SET,
> > +			TEMPSENSE2_LOW_VALUE_MASK);
> > +	}
> > +
> >  	data->irq = platform_get_irq(pdev, 0);
> >  	if (data->irq < 0)
> >  		return data->irq;
> > @@ -489,6 +553,10 @@ static int imx_thermal_probe(struct platform_device *pdev)
> >  	measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
> >  	regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
> >  	imx_set_alarm_temp(data, data->temp_passive);
> > +
> > +	if (data->socdata->version == TEMPMON_V2)
> > +		imx_set_panic_temp(data, data->temp_critical);
> > +
> >  	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
> >  	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
> >  
> > @@ -550,12 +618,6 @@ static int imx_thermal_resume(struct device *dev)
> >  static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
> >  			 imx_thermal_suspend, imx_thermal_resume);
> >  
> > -static const struct of_device_id of_imx_thermal_match[] = {
> > -	{ .compatible = "fsl,imx6q-tempmon", },
> > -	{ /* end */ }
> > -};
> > -MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
> > -
> >  static struct platform_driver imx_thermal = {
> >  	.driver = {
> >  		.name	= "imx_thermal",
> > -- 
> > 1.7.9.5
> > 
>