Commit 10d7e9a9 authored by Daniel Lezcano's avatar Daniel Lezcano Committed by Eduardo Valentin
Browse files

thermal/drivers/hisi: Remove costly sensor inspection 



The sensor is all setup, bind, resetted, acked, etc... every single second.

That was the way to workaround a problem with the interrupt bouncing again and
again.

With the following changes, we fix all in one:

 - Do the setup, one time, at probe time

 - Add the IRQF_ONESHOT, ack the interrupt in the threaded handler

 - Remove the interrupt handler

 - Set the correct value for the LAG register

 - Remove all the irq_enabled stuff in the code as the interruption
   handling is fixed

 - Remove the 3ms delay

 - Reorder the initialization routine to be in the right order

It ends up to a nicer code and more efficient, the 3-5ms delay is removed from
the get_temp() path.

Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: default avatarLeo Yan <leo.yan@linaro.org>
Tested-by: default avatarLeo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent b424315a

drivers/thermal/hisi_thermal.c

+93 −110
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#define HISI_TEMP_BASE			(-60000)

#define HISI_TEMP_RESET			(100000)

#define HISI_TEMP_STEP			(784)

#define HISI_TEMP_LAG			(3500)



#define HISI_MAX_SENSORS		4

#define HISI_DEFAULT_SENSOR		2
@@ -60,8 +61,6 @@ struct hisi_thermal_data { 
	struct clk *clk;

	struct hisi_thermal_sensor sensors;

	int irq;

	bool irq_enabled;



	void __iomem *regs;

};
@@ -99,9 +98,40 @@ static inline long hisi_thermal_round_temp(int temp) 
		hisi_thermal_temp_to_step(temp));

}



/*

 * The lag register contains 5 bits encoding the temperature in steps.

 *

 * Each time the temperature crosses the threshold boundary, an

 * interrupt is raised. It could be when the temperature is going

 * above the threshold or below. However, if the temperature is

 * fluctuating around this value due to the load, we can receive

 * several interrupts which may not desired.

 *

 * We can setup a temperature representing the delta between the

 * threshold and the current temperature when the temperature is

 * decreasing.

 *

 * For instance: the lag register is 5°C, the threshold is 65°C, when

 * the temperature reaches 65°C an interrupt is raised and when the

 * temperature decrease to 65°C - 5°C another interrupt is raised.

 *

 * A very short lag can lead to an interrupt storm, a long lag

 * increase the latency to react to the temperature changes.  In our

 * case, that is not really a problem as we are polling the

 * temperature.

 *

 * [0:4] : lag register

 *

 * The temperature is coded in steps, cf. HISI_TEMP_STEP.

 *

 * Min : 0x00 :  0.0 °C

 * Max : 0x1F : 24.3 °C

 *

 * The 'value' parameter is in milliCelsius.

 */

static inline void hisi_thermal_set_lag(void __iomem *addr, int value)

{

	writel(value, addr + TEMP0_LAG);

	writel((value / HISI_TEMP_STEP) & 0x1F, addr + TEMP0_LAG);

}



static inline void hisi_thermal_alarm_clear(void __iomem *addr, int value)
@@ -171,71 +201,6 @@ static inline void hisi_thermal_hdak_set(void __iomem *addr, int value) 
	       (value << 4), addr + TEMP0_CFG);

}



static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,

					 struct hisi_thermal_sensor *sensor)

{

	long val;



	mutex_lock(&data->thermal_lock);



	/* disable interrupt */

	hisi_thermal_alarm_enable(data->regs, 0);

	hisi_thermal_alarm_clear(data->regs, 1);



	/* disable module firstly */

	hisi_thermal_enable(data->regs, 0);



	/* select sensor id */

	hisi_thermal_sensor_select(data->regs, sensor->id);



	/* enable module */

	hisi_thermal_enable(data->regs, 1);



	usleep_range(3000, 5000);



	val = hisi_thermal_get_temperature(data->regs);



	mutex_unlock(&data->thermal_lock);



	return val;

}



static void hisi_thermal_enable_bind_irq_sensor

			(struct hisi_thermal_data *data)

{

	struct hisi_thermal_sensor *sensor;



	mutex_lock(&data->thermal_lock);



	sensor = &data->sensors;



	/* setting the hdak time */

	hisi_thermal_hdak_set(data->regs, 0);



	/* disable module firstly */

	hisi_thermal_reset_enable(data->regs, 0);

	hisi_thermal_enable(data->regs, 0);



	/* select sensor id */

	hisi_thermal_sensor_select(data->regs, sensor->id);



	/* enable for interrupt */

	hisi_thermal_alarm_set(data->regs, sensor->thres_temp);



	hisi_thermal_reset_set(data->regs, HISI_TEMP_RESET);



	/* enable module */

	hisi_thermal_reset_enable(data->regs, 1);

	hisi_thermal_enable(data->regs, 1);



	hisi_thermal_alarm_clear(data->regs, 0);

	hisi_thermal_alarm_enable(data->regs, 1);



	usleep_range(3000, 5000);



	mutex_unlock(&data->thermal_lock);

}



static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)

{

	mutex_lock(&data->thermal_lock);
@@ -253,25 +218,10 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp) 
	struct hisi_thermal_sensor *sensor = _sensor;

	struct hisi_thermal_data *data = sensor->thermal;



	*temp = hisi_thermal_get_sensor_temp(data, sensor);

	*temp = hisi_thermal_get_temperature(data->regs);



	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%d, thres=%d\n",

		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);

	/*

	 * Bind irq to sensor for two cases:

	 *   Reenable alarm IRQ if temperature below threshold;

	 *   if irq has been enabled, always set it;

	 */

	if (data->irq_enabled) {

		hisi_thermal_enable_bind_irq_sensor(data);

		return 0;

	}



	if (*temp < sensor->thres_temp) {

		data->irq_enabled = true;

		hisi_thermal_enable_bind_irq_sensor(data);

		enable_irq(data->irq);

	}

	dev_dbg(&data->pdev->dev, "id=%d, temp=%d, thres=%d\n",

		sensor->id, *temp, sensor->thres_temp);



	return 0;

}
@@ -280,27 +230,28 @@ static const struct thermal_zone_of_device_ops hisi_of_thermal_ops = { 
	.get_temp = hisi_thermal_get_temp,

};



static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)

{

	struct hisi_thermal_data *data = dev;



	disable_irq_nosync(irq);

	data->irq_enabled = false;



	return IRQ_WAKE_THREAD;

}



static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)

{

	struct hisi_thermal_data *data = dev;

	struct hisi_thermal_sensor *sensor = &data->sensors;

	int temp;



	hisi_thermal_alarm_clear(data->regs, 1);



	temp = hisi_thermal_get_temperature(data->regs);



	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",

		 sensor->thres_temp);

	if (temp >= sensor->thres_temp) {

		dev_crit(&data->pdev->dev, "THERMAL ALARM: %d > %d\n",

			 temp, sensor->thres_temp);



		thermal_zone_device_update(data->sensors.tzd,

					   THERMAL_EVENT_UNSPECIFIED);



	} else if (temp < sensor->thres_temp) {

		dev_crit(&data->pdev->dev, "THERMAL ALARM stopped: %d < %d\n",

			 temp, sensor->thres_temp);

	}



	return IRQ_HANDLED;

}
@@ -352,6 +303,40 @@ static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor, 
		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);

}



static int hisi_thermal_setup(struct hisi_thermal_data *data)

{

	struct hisi_thermal_sensor *sensor;



	sensor = &data->sensors;



	/* disable module firstly */

	hisi_thermal_reset_enable(data->regs, 0);

	hisi_thermal_enable(data->regs, 0);



	/* select sensor id */

	hisi_thermal_sensor_select(data->regs, sensor->id);



	/* setting the hdak time */

	hisi_thermal_hdak_set(data->regs, 0);



	/* setting lag value between current temp and the threshold */

	hisi_thermal_set_lag(data->regs, HISI_TEMP_LAG);



	/* enable for interrupt */

	hisi_thermal_alarm_set(data->regs, sensor->thres_temp);



	hisi_thermal_reset_set(data->regs, HISI_TEMP_RESET);



	/* enable module */

	hisi_thermal_reset_enable(data->regs, 1);

	hisi_thermal_enable(data->regs, 1);



	hisi_thermal_alarm_clear(data->regs, 0);

	hisi_thermal_alarm_enable(data->regs, 1);



	return 0;

}



static int hisi_thermal_probe(struct platform_device *pdev)

{

	struct hisi_thermal_data *data;
@@ -394,9 +379,6 @@ static int hisi_thermal_probe(struct platform_device *pdev) 
		return ret;

	}



	hisi_thermal_enable_bind_irq_sensor(data);

	data->irq_enabled = true;



	ret = hisi_thermal_register_sensor(pdev, data,

					   &data->sensors,

					   HISI_DEFAULT_SENSOR);
@@ -406,18 +388,21 @@ static int hisi_thermal_probe(struct platform_device *pdev) 
		return ret;

	}



	hisi_thermal_toggle_sensor(&data->sensors, true);

	ret = hisi_thermal_setup(data);

	if (ret) {

		dev_err(&pdev->dev, "Failed to setup the sensor: %d\n", ret);

		return ret;

	}



	ret = devm_request_threaded_irq(&pdev->dev, data->irq,

					hisi_thermal_alarm_irq,

	ret = devm_request_threaded_irq(&pdev->dev, data->irq, NULL,

					hisi_thermal_alarm_irq_thread,

					0, "hisi_thermal", data);

					IRQF_ONESHOT, "hisi_thermal", data);

	if (ret < 0) {

		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);

		return ret;

	}



	enable_irq(data->irq);

	hisi_thermal_toggle_sensor(&data->sensors, true);



	return 0;

}
@@ -440,7 +425,6 @@ static int hisi_thermal_suspend(struct device *dev) 
	struct hisi_thermal_data *data = dev_get_drvdata(dev);



	hisi_thermal_disable_sensor(data);

	data->irq_enabled = false;



	clk_disable_unprepare(data->clk);
@@ -456,8 +440,7 @@ static int hisi_thermal_resume(struct device *dev) 
	if (ret)

		return ret;



	data->irq_enabled = true;

	hisi_thermal_enable_bind_irq_sensor(data);

	hisi_thermal_setup(data);



	return 0;

}

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