Re: [PATCH v5 07/18] thermal: exynos: Modify exynos thermal code to use device tree for cpu cooling configuration

Lukasz Majewski
2015-01-21T08:33:04Z

Hi Viresh,

> Up till now exynos_tmu_data.c was used for storing CPU cooling
> configuration data. Now the Exynos thermal core code uses device tree
> to get this data. For this purpose generic thermal code for
> configuring CPU cooling was used.
>
> Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
> ---
> Changes for v2:
> - None
> Changes for v3:
> - Rewrite code responsible for registering CPU cooling device to not
> depend on explicit "/cpus/cpu@0" path since now Exynos SoCs use new
> cpu node names (e.g. cpu@A00). New approach iterates over "cpus" node
> children.
> - Patch title changed to thermal: exynos
> Changes for v4:
> - None
> Changes for v5:
> - None
>
> ---
> drivers/cpufreq/exynos-cpufreq.c | 30 +++++-
> drivers/thermal/samsung/exynos_thermal_common.c | 122
> ++++++++++++++----------
> drivers/thermal/samsung/exynos_tmu.c | 7 --
> drivers/thermal/samsung/exynos_tmu.h | 5 -
> drivers/thermal/samsung/exynos_tmu_data.c | 42 +------- 5
> files changed, 101 insertions(+), 105 deletions(-)
>
> diff --git a/drivers/cpufreq/exynos-cpufreq.c
> b/drivers/cpufreq/exynos-cpufreq.c index f99a0b0..32bc64d 100644
> --- a/drivers/cpufreq/exynos-cpufreq.c
> +++ b/drivers/cpufreq/exynos-cpufreq.c
> @@ -18,10 +18,13 @@
> #include <linux/cpufreq.h>
> #include <linux/platform_device.h>
> #include <linux/of.h>
> +#include <linux/cpu_cooling.h>
> +#include <linux/cpu.h>
>
> #include "exynos-cpufreq.h"
>
> static struct exynos_dvfs_info *exynos_info;
> +static struct thermal_cooling_device *cdev;
> static struct regulator *arm_regulator;
> static unsigned int locking_frequency;
>
> @@ -156,6 +159,7 @@ static struct cpufreq_driver exynos_driver = {
>
> static int exynos_cpufreq_probe(struct platform_device *pdev)
> {
> + struct device_node *cpus, *np;
> int ret = -EINVAL;
>
> exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL);
> @@ -198,9 +202,31 @@ static int exynos_cpufreq_probe(struct
> platform_device *pdev) /* Done here as we want to capture boot
> frequency */ locking_frequency = clk_get_rate(exynos_info->cpu_clk) /
> 1000;
> - if (!cpufreq_register_driver(&exynos_driver))
> - return 0;
> + if (cpufreq_register_driver(&exynos_driver))
> + goto err;
>
> + cpus = of_find_node_by_path("/cpus");
> + if (!cpus) {
> + pr_err("failed to find cpus node\n");
> + return -ENOENT;
> + }
> +
> + for (np = of_get_next_child(cpus, NULL); np;
> + of_node_put(np), np = of_get_next_child(cpus, np)) {
> + if (of_find_property(np, "#cooling-cells", NULL)) {
> + cdev = of_cpufreq_cooling_register(np,
> +
> cpu_present_mask);
> + if (IS_ERR(cdev))
> + pr_err("running cpufreq without
> cooling device: %ld\n",
> + PTR_ERR(cdev));
> + break;
> + }
> + }
> + of_node_put(np);
> + of_node_put(cpus);
> +
> + return 0;
> + err:
> dev_err(&pdev->dev, "failed to register cpufreq driver\n");
> regulator_put(arm_regulator);
> err_vdd_arm:

Viresh, the above is a small part of the cpufreq related code, which is
necessary for Exynos thermal rework to use device tree.

It is NOT adding any new functionality, but preserves possibility to
use cpufreq as a colling device.

Normally I would exclude this part from this commit, but then I cannot
assure that between commits no regression is slipping in.

> diff --git a/drivers/thermal/samsung/exynos_thermal_common.c
> b/drivers/thermal/samsung/exynos_thermal_common.c index
> 6dc3815..00aa688 100644 ---
> a/drivers/thermal/samsung/exynos_thermal_common.c +++
> b/drivers/thermal/samsung/exynos_thermal_common.c @@ -133,47 +133,62
> @@ static int exynos_get_crit_temp(struct thermal_zone_device
> *thermal, static int exynos_bind(struct thermal_zone_device *thermal,
> struct thermal_cooling_device *cdev) {
> - int ret = 0, i, tab_size, level;
> - struct freq_clip_table *tab_ptr, *clip_data;
> struct exynos_thermal_zone *th_zone = thermal->devdata;
> struct thermal_sensor_conf *data = th_zone->sensor_conf;
> + struct device_node *child, *gchild, *np;
> + struct of_phandle_args cooling_spec;
> + unsigned long max, state = 0;
> + int ret = 0, i = 0;
>
> - tab_ptr = (struct freq_clip_table
> *)data->cooling_data.freq_data;
> - tab_size = data->cooling_data.freq_clip_count;
> -
> - if (tab_ptr == NULL || tab_size == 0)
> + /*
> + * Below code is necessary to skip binding when cpufreq's
> + * frequency table is not yet initialized.
> + */
> + cdev->ops->get_max_state(cdev, &state);
> + if (!state && !th_zone->cool_dev_size) {
> + th_zone->cool_dev_size = 1;
> + th_zone->cool_dev[0] = cdev;
> + th_zone->bind = false;
> return 0;
> + }
>
> - /* find the cooling device registered*/
> - for (i = 0; i < th_zone->cool_dev_size; i++)
> - if (cdev == th_zone->cool_dev[i])
> - break;
> + np = of_find_node_by_path("/thermal-zones/cpu-thermal");
> + if (!np) {
> + pr_err("failed to find thmerla-zones/cpu-thermal
> node\n");
> + return -ENOENT;
> + }
>
> - /* No matching cooling device */
> - if (i == th_zone->cool_dev_size)
> - return 0;
> + child = of_get_child_by_name(np, "cooling-maps");
>
> - /* Bind the thermal zone to the cpufreq cooling device */
> - for (i = 0; i < tab_size; i++) {
> - clip_data = (struct freq_clip_table *)&(tab_ptr[i]);
> - level = cpufreq_cooling_get_level(0,
> clip_data->freq_clip_max);
> - if (level == THERMAL_CSTATE_INVALID)
> - return 0;
> - switch (GET_ZONE(i)) {
> - case MONITOR_ZONE:
> - case WARN_ZONE:
> - if
> (thermal_zone_bind_cooling_device(thermal, i, cdev,
> -
> level, 0)) {
> - dev_err(data->dev,
> - "error unbinding cdev
> inst=%d\n", i);
> - ret = -EINVAL;
> - }
> - th_zone->bind = true;
> - break;
> - default:
> + for_each_child_of_node(child, gchild) {
> + ret = of_parse_phandle_with_args(gchild,
> "cooling-device",
> + "#cooling-cells",
> + 0, &cooling_spec);
> + if (ret < 0) {
> + pr_err("missing cooling_device property\n");
> + goto end;
> + }
> +
> + if (cooling_spec.args_count < 2) {
> ret = -EINVAL;
> + goto end;
> }
> +
> + max = cooling_spec.args[0];
> + if (thermal_zone_bind_cooling_device(thermal, i,
> cdev,
> + max, 0)) {
> + dev_err(data->dev,
> + "thermal error unbinding cdev
> inst=%d\n", i); +
> + ret = -EINVAL;
> + goto end;
> + }
> + i++;
> }
> + th_zone->bind = true;
> +end:
> + of_node_put(child);
> + of_node_put(np);
>
> return ret;
> }
> @@ -182,16 +197,12 @@ static int exynos_bind(struct
> thermal_zone_device *thermal, static int exynos_unbind(struct
> thermal_zone_device *thermal, struct thermal_cooling_device *cdev)
> {
> - int ret = 0, i, tab_size;
> + int ret = 0, i;
> struct exynos_thermal_zone *th_zone = thermal->devdata;
> struct thermal_sensor_conf *data = th_zone->sensor_conf;
> + struct device_node *child, *gchild, *np;
>
> - if (th_zone->bind == false)
> - return 0;
> -
> - tab_size = data->cooling_data.freq_clip_count;
> -
> - if (tab_size == 0)
> + if (th_zone->bind == false || !th_zone->cool_dev_size)
> return 0;
>
> /* find the cooling device registered*/
> @@ -203,23 +214,30 @@ static int exynos_unbind(struct
> thermal_zone_device *thermal, if (i == th_zone->cool_dev_size)
> return 0;
>
> - /* Bind the thermal zone to the cpufreq cooling device */
> - for (i = 0; i < tab_size; i++) {
> - switch (GET_ZONE(i)) {
> - case MONITOR_ZONE:
> - case WARN_ZONE:
> - if
> (thermal_zone_unbind_cooling_device(thermal, i,
> -
> cdev)) {
> - dev_err(data->dev,
> - "error unbinding cdev
> inst=%d\n", i);
> - ret = -EINVAL;
> - }
> - th_zone->bind = false;
> - break;
> - default:
> + np = of_find_node_by_path("/thermal-zones/cpu-thermal");
> + if (!np) {
> + pr_err("failed to find thmerla-zones/cpu-thermal
> node\n");
> + return -ENOENT;
> + }
> +
> + child = of_get_child_by_name(np, "cooling-maps");
> +
> + i = 0;
> + for_each_child_of_node(child, gchild) {
> + if (thermal_zone_unbind_cooling_device(thermal, i,
> + cdev)) {
> + dev_err(data->dev,
> + "error unbinding cdev inst=%d\n", i);
> ret = -EINVAL;
> + goto end;
> }
> + i++;
> }
> + th_zone->bind = false;
> +end:
> + of_node_put(child);
> + of_node_put(np);
> +
> return ret;
> }
>
> diff --git a/drivers/thermal/samsung/exynos_tmu.c
> b/drivers/thermal/samsung/exynos_tmu.c index 5000727..ae30f6a 100644
> --- a/drivers/thermal/samsung/exynos_tmu.c
> +++ b/drivers/thermal/samsung/exynos_tmu.c
> @@ -916,13 +916,6 @@ static int exynos_tmu_probe(struct
> platform_device *pdev)
> sensor_conf->trip_data.trigger_falling =
> pdata->threshold_falling;
> - sensor_conf->cooling_data.freq_clip_count =
> pdata->freq_tab_count;
> - for (i = 0; i < pdata->freq_tab_count; i++) {
> - sensor_conf->cooling_data.freq_data[i].freq_clip_max
> =
> -
> pdata->freq_tab[i].freq_clip_max;
> - sensor_conf->cooling_data.freq_data[i].temp_level =
> -
> pdata->freq_tab[i].temp_level;
> - }
> sensor_conf->dev = &pdev->dev;
> /* Register the sensor with thermal management interface */
> ret = exynos_register_thermal(sensor_conf);
> diff --git a/drivers/thermal/samsung/exynos_tmu.h
> b/drivers/thermal/samsung/exynos_tmu.h index 7f880d2..627dec9 100644
> --- a/drivers/thermal/samsung/exynos_tmu.h
> +++ b/drivers/thermal/samsung/exynos_tmu.h
> @@ -83,9 +83,6 @@ enum soc_type {
> * @second_point_trim: temp value of the second point trimming
> * @default_temp_offset: default temperature offset in case of no
> trimming
> * @cal_type: calibration type for temperature
> - * @freq_clip_table: Table representing frequency reduction
> percentage.
> - * @freq_tab_count: Count of the above table as frequency reduction
> may
> - * applicable to only some of the trigger levels.
> *
> * This structure is required for configuration of exynos_tmu driver.
> */
> @@ -111,8 +108,6 @@ struct exynos_tmu_platform_data {
> enum soc_type type;
> u32 cal_type;
> u32 cal_mode;
> - struct freq_clip_table freq_tab[4];
> - unsigned int freq_tab_count;
> };
>
> /**
> diff --git a/drivers/thermal/samsung/exynos_tmu_data.c
> b/drivers/thermal/samsung/exynos_tmu_data.c index b239100..a993f3d
> 100644 --- a/drivers/thermal/samsung/exynos_tmu_data.c
> +++ b/drivers/thermal/samsung/exynos_tmu_data.c
> @@ -47,15 +47,6 @@ struct exynos_tmu_init_data const
> exynos4210_default_tmu_data = { .first_point_trim = 25,
> .second_point_trim = 85,
> .default_temp_offset = 50,
> - .freq_tab[0] = {
> - .freq_clip_max = 800 * 1000,
> - .temp_level = 85,
> - },
> - .freq_tab[1] = {
> - .freq_clip_max = 200 * 1000,
> - .temp_level = 100,
> - },
> - .freq_tab_count = 2,
> .type = SOC_ARCH_EXYNOS4210,
> },
> },
> @@ -87,16 +78,7 @@ struct exynos_tmu_init_data const
> exynos4210_default_tmu_data = { .max_efuse_value = 100, \
> .first_point_trim = 25, \
> .second_point_trim = 85, \
> - .default_temp_offset = 50, \
> - .freq_tab[0] = { \
> - .freq_clip_max = 800 * 1000, \
> - .temp_level = 70, \
> - }, \
> - .freq_tab[1] = { \
> - .freq_clip_max = 400 * 1000, \
> - .temp_level = 95, \
> - }, \
> - .freq_tab_count = 2
> + .default_temp_offset = 50
>
> struct exynos_tmu_init_data const exynos3250_default_tmu_data = {
> .tmu_data = {
> @@ -133,16 +115,7 @@ struct exynos_tmu_init_data const
> exynos3250_default_tmu_data = { .max_efuse_value = 100, \
> .first_point_trim = 25, \
> .second_point_trim = 85, \
> - .default_temp_offset = 50, \
> - .freq_tab[0] = { \
> - .freq_clip_max = 1400 * 1000, \
> - .temp_level = 70, \
> - }, \
> - .freq_tab[1] = { \
> - .freq_clip_max = 400 * 1000, \
> - .temp_level = 95, \
> - }, \
> - .freq_tab_count = 2
> + .default_temp_offset = 50
>
> struct exynos_tmu_init_data const exynos4412_default_tmu_data = {
> .tmu_data = {
> @@ -189,16 +162,7 @@ struct exynos_tmu_init_data const
> exynos5250_default_tmu_data = { .max_efuse_value = 100, \
> .first_point_trim = 25, \
> .second_point_trim = 85, \
> - .default_temp_offset = 50, \
> - .freq_tab[0] = { \
> - .freq_clip_max = 800 * 1000, \
> - .temp_level = 85, \
> - }, \
> - .freq_tab[1] = { \
> - .freq_clip_max = 200 * 1000, \
> - .temp_level = 103, \
> - }, \
> - .freq_tab_count = 2, \
> + .default_temp_offset = 50,
>
> #define EXYNOS5260_TMU_DATA \
> __EXYNOS5260_TMU_DATA \

--
Best regards,

Lukasz Majewski

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