Re: [PATCH V3] Thermal: imx: add i.mx6sx thermal support

edubezval
2014-08-06T13:24:51Z

Hello Anson,

On Wed, Aug 6, 2014 at 3:12 AM, Anson Huang <b20788@freescale.com> 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.

So far the patch is pretty much better now. Unfortunately, I do not
have a way to test it. Can you please check if some workmate of yours
can do a testing on both hardwares and send his/her tested-by?

>
> Signed-off-by: Anson Huang <b20788@freescale.com>
> ---
> .../devicetree/bindings/thermal/imx-thermal.txt | 5 +-
> drivers/thermal/imx_thermal.c | 91 +++++++++++++++++---
> 2 files changed, 82 insertions(+), 14 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/thermal/imx-thermal.txt b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> index 1f0f672..3c67bd5 100644
> --- a/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> +++ b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> @@ -1,7 +1,10 @@
> * Temperature Monitor (TEMPMON) on Freescale i.MX SoCs
>
> Required properties:
> -- compatible : "fsl,imx6q-thermal"
> +- compatible : "fsl,imx6q-tempmon" for i.MX6Q, "fsl,imx6sx-tempmon" for i.MX6SX.
> + i.MX6SX has two more IRQs than i.MX6Q, one is IRQ_LOW and the other is IRQ_PANIC,
> + when temperature is below than low threshold, IRQ_LOW will be triggered, when temperature
> + is higher than panic threshold, system will auto reboot by SRC module.
> - 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..461bf3d 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 +32,11 @@
>
> #define MISC0 0x0150
> #define MISC0_REFTOP_SELBIASOFF (1 << 3)
> +#define MISC1 0x0160
> +#define MISC1_IRQ_TEMPHIGH (1 << 29)
> +/* Below LOW and PANIC bits are only for TEMPMON_IMX6SX */
> +#define MISC1_IRQ_TEMPLOW (1 << 28)
> +#define MISC1_IRQ_TEMPPANIC (1 << 27)
>
> #define TEMPSENSE0 0x0180
> #define TEMPSENSE0_ALARM_VALUE_SHIFT 20
> @@ -43,6 +49,12 @@
>
> #define TEMPSENSE1 0x0190
> #define TEMPSENSE1_MEASURE_FREQ 0xffff
> +/* Below TEMPSENSE2 is only for TEMPMON_IMX6SX */
> +#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
>
> #define OCOTP_ANA1 0x04e0
>
> @@ -66,6 +78,21 @@ enum imx_thermal_trip {
> #define FACTOR1 15976
> #define FACTOR2 4297157
>
> +#define TEMPMON_IMX6Q 1
> +#define TEMPMON_IMX6SX 2
> +
> +struct thermal_soc_data {
> + u32 version;
> +};
> +
> +static struct thermal_soc_data thermal_imx6q_data = {
> + .version = TEMPMON_IMX6Q,
> +};
> +
> +static struct thermal_soc_data thermal_imx6sx_data = {
> + .version = TEMPMON_IMX6SX,
> +};
> +
> struct imx_thermal_data {
> struct thermal_zone_device *tz;
> struct thermal_cooling_device *cdev;
> @@ -79,8 +106,21 @@ 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 +182,17 @@ 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 for TEMPMON_IMX6Q */
> + if (data->socdata->version == TEMPMON_IMX6Q) {
> + 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 +442,17 @@ 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 +471,20 @@ 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 enabling irq on i.MX6SX */
> + if (data->socdata->version == TEMPMON_IMX6SX) {

A general question on the patch strategy. You have chosen to split the
features per chip version. While this strategy is straight forward,
and one would even say very natural, I would say it is not very
scalable. In case your next chip versions have an overlap in features
with the existing ones, you will make your code a nightmare of ifs per
chip version. One suggestion is, that I have experienced to work with
TI and Samsung chips, to split the code per feature, not per chip
version.

In chis case, you will have a .supports or .features bitfield instead
of a .version. Then you would check if particular feature is present
in the chip you are dealing with, instead of asking for chip version.
What do you think?

> + regmap_write(map, MISC1 + REG_CLR, MISC1_IRQ_TEMPHIGH |
> + 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 +556,10 @@ 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_IMX6SX)
> + 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 +621,6 @@ 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
>

--
Eduardo Bezerra Valentin