thermal: rockchip: rk3368: ajust tsadc's data path according request of qos

we dynamically ajust data path according to request of qos to do
the balance between system's performance and tsadc's precision.

Change-Id: Iec6d6af6efce3932f894d9a07298daa9653cc87e
Signed-off-by: Rocky Hao <rocky.hao@rock-chips.com>

diff --git a/drivers/thermal/rk3368_thermal.c b/drivers/thermal/rk3368_thermal.c
index 290bd4d5aad89a5593948d99059871e460e2d6a8..937c0b67f104a9705d152f2101f51a7326c0812e 100644 (file)
--- a/drivers/thermal/rk3368_thermal.c
+++ b/drivers/thermal/rk3368_thermal.c
@@ -33,6 +33,8 @@
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/nvmem-consumer.h>
+#include <linux/pm_qos.h>
+#include <soc/rockchip/scpi.h>
 
 /**
  * If the temperature over a period of time High,
@@ -142,6 +144,7 @@ struct rk3368_tsadc_chip {
        enum tshut_mode tshut_mode;
        enum tsadc_mode mode;
        enum tshut_polarity tshut_polarity;
+       int latency_bound;
 
        const struct chip_tsadc_table *temp_table;
 
@@ -207,6 +210,8 @@ struct rk3368_thermal_data {
        struct kobject *rk3368_thermal_kobj;
        struct regulator *ref_regulator;
        int regulator_uv;
+       int latency_req;
+       int latency_bound;
        struct notifier_block tsadc_nb;
 };
 
@@ -214,6 +219,8 @@ static struct rk3368_thermal_data *thermal_ctx;
 
 static DEFINE_MUTEX(thermal_reg_mutex);
 
+static DEFINE_MUTEX(thermal_lat_mutex);
+
 static const struct tsadc_table code_table_3368[] = {
        {0, MIN_TEMP},
        {106, MIN_TEMP},
@@ -413,6 +420,7 @@ static int rk3368_code_to_temp(const struct chip_tsadc_table *tmp_table,
 static const struct rk3368_tsadc_chip rk3368_tsadc_data = {
        .tshut_mode = TSHUT_MODE_GPIO,  /* default TSHUT via GPIO give PMIC */
        .tshut_polarity = TSHUT_LOW_ACTIVE,     /* default TSHUT LOW ACTIVE */
+       .latency_bound = 50000, /* default 50000 us */
        .hw_shut_temp = 125000,
        .mode = TSHUT_USER_MODE,
        .chn_num = 2,
@@ -427,6 +435,8 @@ static int rk3368_configure_from_dt(struct device *dev,
 {
        u32 shut_temp;
        u32 rate;
+       u32 cycle;
+       int lat_bound;
        int ret;
 
        if (of_property_read_u32(np, "clock-frequency", &rate)) {
@@ -435,6 +445,13 @@ static int rk3368_configure_from_dt(struct device *dev,
        }
        ret = clk_set_rate(thermal->clk, rate);
 
+       cycle = DIV_ROUND_UP(1000000000, rate) / 1000;
+
+       if (scpi_thermal_set_clk_cycle(cycle)) {
+               dev_err(dev, "scpi_thermal_set_clk_cycle error.\n");
+               return -EINVAL;
+       }
+
        if (of_property_read_u32(np, "hw-shut-temp", &shut_temp)) {
                dev_warn(dev,
                         "Missing tshut temp property, using default %ld\n",
@@ -444,6 +461,15 @@ static int rk3368_configure_from_dt(struct device *dev,
                thermal->hw_shut_temp = shut_temp;
        }
 
+       if (of_property_read_u32(np, "latency-bound", &lat_bound)) {
+               dev_warn(dev,
+                        "Missing latency-bound property, using default %d\n",
+                        thermal->chip->latency_bound);
+               thermal->latency_bound = thermal->chip->latency_bound;
+       } else {
+               thermal->latency_bound = lat_bound;
+       }
+
        if (thermal->hw_shut_temp > INT_MAX) {
                dev_err(dev, "Invalid tshut temperature specified: %ld\n",
                        thermal->hw_shut_temp);
@@ -538,12 +564,15 @@ static int get_raw_code_internal(void)
 #define RAW_CODE_MIN (50)
 #define RAW_CODE_MAX (225)
 
-static int rk3368_get_raw_code(void)
+static int rk3368_get_raw_code(struct rk3368_thermal_data *ctx)
 {
        static int old_data = 130;
        int tsadc_data = 0;
 
-       tsadc_data = get_raw_code_internal();
+       if (ctx->latency_req > ctx->latency_bound)
+               tsadc_data = scpi_thermal_get_temperature();
+       else
+               tsadc_data = get_raw_code_internal();
 
        if ((tsadc_data < RAW_CODE_MIN) || (tsadc_data > RAW_CODE_MAX))
                tsadc_data = old_data;
@@ -609,7 +638,7 @@ static int rk3368_thermal_get_temp(void *_sensor, int *out_temp)
        pdev = ctx->pdev;
 
        mutex_lock(&thermal_reg_mutex);
-       raw_code = rk3368_get_raw_code();
+       raw_code = rk3368_get_raw_code(ctx);
        temp = rk3368_convert_code_2_temp(raw_code, ctx->regulator_uv);
        *out_temp = predict_temp(temp / 1000) * 1000;
        mutex_unlock(&thermal_reg_mutex);
@@ -831,6 +860,39 @@ static int rk3368_thermal_notify(struct notifier_block *nb,
        return NOTIFY_OK;
 }
 
+/*
+ * This function gets called when a part of the kernel has a new latency
+ * requirement. We record this requirement to instruct us to get temperature.
+ */
+static int tsadc_latency_notify(struct notifier_block *b,
+                               unsigned long l, void *v)
+{
+       struct rk3368_thermal_data *ctx = rk3368_thermal_get_data();
+
+       if (!ctx)
+               return NOTIFY_OK;
+
+       mutex_lock(&thermal_lat_mutex);
+       ctx->latency_req = (int)l;
+       mutex_unlock(&thermal_lat_mutex);
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block tsadc_latency_notifier = {
+       .notifier_call = tsadc_latency_notify,
+};
+
+static inline int tsadc_add_latency_notifier(struct notifier_block *n)
+{
+       return pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n);
+}
+
+static inline int tsadc_remove_latency_notifier(struct notifier_block *n)
+{
+       return pm_qos_remove_notifier(PM_QOS_CPU_DMA_LATENCY, n);
+}
+
 static const struct of_device_id of_rk3368_thermal_match[] = {
        {
         .compatible = "rockchip,rk3368-tsadc-legacy",
@@ -852,6 +914,7 @@ static int rk3368_thermal_probe(struct platform_device *pdev)
        int error;
        int uv;
        int ajust_code = 0;
+       int latency_req = 0;
 
        match = of_match_node(of_rk3368_thermal_match, np);
        if (!match)
@@ -956,6 +1019,19 @@ static int rk3368_thermal_probe(struct platform_device *pdev)
                ctx->regulator_uv = uv;
        mutex_unlock(&thermal_reg_mutex);
 
+       error = tsadc_add_latency_notifier(&tsadc_latency_notifier);
+       if (error) {
+               dev_err(&pdev->dev, "latency notifier request failed\n");
+               goto err_unreg_notifier;
+       }
+
+       latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
+
+       mutex_lock(&thermal_lat_mutex);
+       if (!ctx->latency_req)
+               ctx->latency_req = latency_req;
+       mutex_unlock(&thermal_lat_mutex);
+
        rk3368_get_ajust_code(np, &ajust_code);
 
        ctx->cpu_temp_adjust = (int)ajust_code;
@@ -971,7 +1047,7 @@ static int rk3368_thermal_probe(struct platform_device *pdev)
                        for (j = 0; j < i; j++)
                                thermal_zone_of_sensor_unregister(&pdev->dev,
                                                                  ctx->sensors[j].tzd);
-                       goto err_unreg_notifier;
+                       goto err_remove_latancy_notifier;
                }
        }
 
@@ -981,7 +1057,7 @@ static int rk3368_thermal_probe(struct platform_device *pdev)
                error = -ENOMEM;
                dev_err(&pdev->dev,
                        "failed to creat debug node : error= %d\n", error);
-               goto err_unreg_notifier;
+               goto err_remove_latancy_notifier;
        }
 
        for (i = 0; i < ARRAY_SIZE(rk3368_thermal_attrs); i++) {
@@ -996,7 +1072,7 @@ static int rk3368_thermal_probe(struct platform_device *pdev)
                                sysfs_remove_file(ctx->rk3368_thermal_kobj,
                                                  &rk3368_thermal_attrs[j].attr);
 
-                       goto err_unreg_notifier;
+                       goto err_remove_latancy_notifier;
                }
        }
 
@@ -1011,6 +1087,8 @@ static int rk3368_thermal_probe(struct platform_device *pdev)
 
        return 0;
 
+err_remove_latancy_notifier:
+       tsadc_remove_latency_notifier(&tsadc_latency_notifier);
 err_unreg_notifier:
        regulator_unregister_notifier(ctx->ref_regulator, &ctx->tsadc_nb);
 
@@ -1027,11 +1105,15 @@ static int rk3368_thermal_remove(struct platform_device *pdev)
        struct rk3368_thermal_data *ctx = platform_get_drvdata(pdev);
        int i;
 
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &rk3368_thermal_panic_block);
        for (i = 0; i < ctx->chip->chn_num; i++) {
                struct rk3368_thermal_sensor *sensor = &ctx->sensors[i];
 
                thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
        }
+       tsadc_remove_latency_notifier(&tsadc_latency_notifier);
+       regulator_unregister_notifier(ctx->ref_regulator, &ctx->tsadc_nb);
        clk_disable_unprepare(ctx->pclk);
        clk_disable_unprepare(ctx->clk);