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

Apurva Nandan
2023-08-09T17:39:28Z

From: Keerthy <j-keerthy@ti.com>

Add cpufreq as a cooling device, based on the inputs from the thermal
sensors.

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);

--
2.34.1