Re: [PATCH 1/3] thermal: k3_j72xx_bandgap: Add cooling device support

Daniel Lezcano
2023-08-16T10:16:21Z

On 09/08/2023 19:39, Apurva Nandan wrote:
> From: Keerthy <j-keerthy@ti.com>
>
> Add cpufreq as a cooling device, based on the inputs from the thermal
> sensors.

I don't understand these changes.

By using the DT, it is all done automatically, no ?

>
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> Signed-off-by: Apurva Nandan <a-nandan@ti.com>
> ---
> drivers/thermal/k3_j72xx_bandgap.c | 121 +++++++++++++++++++++++++++++
> 1 file changed, 121 insertions(+)
>
> diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
> index a5a0fc9b9356..c844cb527761 100644
> --- a/drivers/thermal/k3_j72xx_bandgap.c
> +++ b/drivers/thermal/k3_j72xx_bandgap.c
> @@ -19,6 +19,9 @@
> #include <linux/of.h>
> #include <linux/delay.h>
> #include <linux/slab.h>
> +#include <linux/cpufreq.h>
> +#include <linux/cpumask.h>
> +#include <linux/cpu_cooling.h>
>
> #define K3_VTM_DEVINFO_PWR0_OFFSET 0x4
> #define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK 0xf0
> @@ -183,10 +186,28 @@ struct k3_j72xx_bandgap {
> /* common data structures */
> struct k3_thermal_data {
> struct k3_j72xx_bandgap *bgp;
> + struct cpufreq_policy *policy;
> + struct thermal_zone_device *ti_thermal;
> + struct thermal_cooling_device *cool_dev;
> + struct work_struct thermal_wq;
> u32 ctrl_offset;
> u32 stat_offset;
> + enum thermal_device_mode mode;
> + int prev_temp;
> + int sensor_id;
> };
>
> +static void k3_thermal_work(struct work_struct *work)
> +{
> + struct k3_thermal_data *data = container_of(work,
> + struct k3_thermal_data, thermal_wq);
> +
> + thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED);
> +
> + dev_info(&data->ti_thermal->device, "updated thermal zone %s\n",
> + data->ti_thermal->type);
> +}
> +
> static int two_cmp(int tmp, int mask)
> {
> tmp = ~(tmp);
> @@ -251,8 +272,40 @@ static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
> return k3_bgp_read_temp(thermal_zone_device_priv(tz), temp);
> }
>
> +static int k3_thermal_get_trend(struct thermal_zone_device *tz, int trip, enum thermal_trend *trend)
> +{
> + struct k3_thermal_data *data = tz->devdata;
> + struct k3_j72xx_bandgap *bgp;
> + u32 temp1, temp2;
> + int tr, ret = 0;
> +
> + bgp = data->bgp;
> +
> + ret = k3_thermal_get_temp(tz, &temp1);
> + if (ret)
> + return ret;
> + temp2 = data->prev_temp;
> +
> + tr = temp1 - temp2;
> +
> + data->prev_temp = temp1;
> +
> + if (tr > 0)
> + *trend = THERMAL_TREND_RAISING;
> + else if (tr < 0)
> + *trend = THERMAL_TREND_DROPPING;
> + else
> + *trend = THERMAL_TREND_STABLE;
> +
> + dev_dbg(bgp->dev, "The temperatures are t1 = %d and t2 = %d and trend =%d\n",
> + temp1, temp2, *trend);
> +
> + return ret;
> +}
> +
> static const struct thermal_zone_device_ops k3_of_thermal_ops = {
> .get_temp = k3_thermal_get_temp,
> + .get_trend = k3_thermal_get_trend,
> };
>
> static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
> @@ -342,6 +395,63 @@ struct k3_j72xx_bandgap_data {
> const bool has_errata_i2128;
> };
>
> +static int k3_thermal_register_cpu_cooling(struct k3_j72xx_bandgap *bgp, int id)
> +{
> + struct k3_thermal_data *data;
> + struct device_node *np = bgp->dev->of_node;
> +
> + /*
> + * We are assuming here that if one deploys the zone
> + * using DT, then it must be aware that the cooling device
> + * loading has to happen via cpufreq driver.
> + */
> + if (of_find_property(np, "#thermal-sensor-cells", NULL))
> + return 0;
> +
> + data = bgp->ts_data[id];
> + if (!data)
> + return -EINVAL;
> +
> + data->policy = cpufreq_cpu_get(0);
> + if (!data->policy) {
> + pr_debug("%s: CPUFreq policy not found\n", __func__);
> + return -EPROBE_DEFER;
> + }
> +
> + /* Register cooling device */
> + data->cool_dev = cpufreq_cooling_register(data->policy);
> + if (IS_ERR(data->cool_dev)) {
> + int ret = PTR_ERR(data->cool_dev);
> +
> + dev_err(bgp->dev, "Failed to register cpu cooling device %d\n",
> + ret);
> + cpufreq_cpu_put(data->policy);
> +
> + return ret;
> + }
> +
> + data->mode = THERMAL_DEVICE_ENABLED;
> +
> + INIT_WORK(&data->thermal_wq, k3_thermal_work);
> +
> + return 0;
> +}
> +
> +static int k3_thermal_unregister_cpu_cooling(struct k3_j72xx_bandgap *bgp, int id)
> +{
> + struct k3_thermal_data *data;
> +
> + data = bgp->ts_data[id];
> +
> + if (!IS_ERR_OR_NULL(data)) {
> + cpufreq_cooling_unregister(data->cool_dev);
> + if (data->policy)
> + cpufreq_cpu_put(data->policy);
> + }
> +
> + return 0;
> +}
> +
> static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
> {
> int ret = 0, cnt, val, id;
> @@ -452,6 +562,7 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
> /* Register the thermal sensors */
> for (id = 0; id < cnt; id++) {
> data[id].bgp = bgp;
> + data[id].sensor_id = id;
> data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
> data[id].stat_offset = data[id].ctrl_offset +
> K3_VTM_TMPSENS_STAT_OFFSET;
> @@ -477,6 +588,12 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
> writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
>
> bgp->ts_data[id] = &data[id];
> +
> + if (id == 1)
> + ret = k3_thermal_register_cpu_cooling(bgp, 1);
> + if (ret)
> + goto err_alloc;
> +
> ti_thermal = devm_thermal_of_zone_register(bgp->dev, id, &data[id],
> &k3_of_thermal_ops);
> if (IS_ERR(ti_thermal)) {
> @@ -514,6 +631,7 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
> return 0;
>
> err_free_ref_table:
> + k3_thermal_unregister_cpu_cooling(bgp, 1);
> kfree(ref_table);
>
> err_alloc:
> @@ -525,6 +643,9 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
>
> static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
> {
> + struct k3_j72xx_bandgap *bgp = platform_get_drvdata(pdev);
> +
> + k3_thermal_unregister_cpu_cooling(bgp, 1);
> pm_runtime_put_sync(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
>

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