On 23 October 2012 02:51, Francesco Lavra [off-list ref] wrote:

On 10/22/2012 02:02 PM, Hongbo Zhang wrote:
[...]

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+static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
+{
+     struct db8500_thermal_zone *pzone = irq_data;
+     struct db8500_thsens_platform_data *ptrips;
+     unsigned long next_low, next_high;
+     unsigned int idx;
+
+     ptrips = pzone->trip_tab;
+     idx = pzone->cur_index;
+     if (unlikely(idx == 0))
+             /* Meaningless for thermal management, ignoring it */
+             return IRQ_HANDLED;
+
+     if (idx == 1) {
+             next_high = ptrips->trip_points[0].temp;
+             next_low = PRCMU_DEFAULT_LOW_TEMP;
+     } else {
+             next_high = ptrips->trip_points[idx-1].temp;
+             next_low = ptrips->trip_points[idx-2].temp;
+     }
+
+     pzone->cur_index -= 1;
+     pzone->cur_temp_pseudo = (next_high + next_low)/2;
+
+     prcmu_stop_temp_sense();
+     prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
+     prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
+
+     pr_debug("PRCMU set max %ld, set min %ld\n", next_high, next_low);
+
+     pzone->trend = THERMAL_TREND_DROPPING;
+     schedule_work(&pzone->therm_work);
+
+     return IRQ_HANDLED;
+}
+
+static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
+{
+     struct db8500_thermal_zone *pzone = irq_data;
+     struct db8500_thsens_platform_data *ptrips;
+     unsigned long next_low, next_high;
+     unsigned int idx;
+
+     ptrips = pzone->trip_tab;
+     idx = pzone->cur_index;
+
+     if (idx < ptrips->num_trips - 1) {
+             next_high = ptrips->trip_points[idx+1].temp;
+             next_low = ptrips->trip_points[idx].temp;
+
+             pzone->cur_index += 1;
+             pzone->cur_temp_pseudo = (next_high + next_low)/2;
+
+             prcmu_stop_temp_sense();
+             prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
+             prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
+
+             pr_debug("PRCMU set max %ld, min %ld\n", next_high, next_low);
+     }
+
+     if (idx == ptrips->num_trips - 1)

} else if ()

There is no else condition here, because it it the highest critical
trip point, system will be shut down in thermal_work.
But I'd like to add some comments here to state this situation.

I didn't mean adding a new else condition, what I meant is that if the
first condition (idx < ptrips->num_trips - 1) is verified, then there is
no need to check for the second condition (idx == ptrips->num_trips -
1). So I was thinking of changing the code to:

if (idx < ptrips->num_trips - 1)
        ...
else if (idx == ptrips->num_trips - 1)
        ...

Sorry if I wasn't clear.

Got it, thanks.

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+             pzone->cur_temp_pseudo = ptrips->trip_points[idx].temp + 1;
+
+     pzone->trend = THERMAL_TREND_RAISING;
+     schedule_work(&pzone->therm_work);
+
+     return IRQ_HANDLED;
+}
+
+static void db8500_thermal_work(struct work_struct *work)
+{
+     enum thermal_device_mode cur_mode;
+     struct db8500_thermal_zone *pzone;
+
+     pzone = container_of(work, struct db8500_thermal_zone, therm_work);
+
+     mutex_lock(&pzone->th_lock);
+     cur_mode = pzone->mode;
+     mutex_unlock(&pzone->th_lock);
+
+     if (cur_mode == THERMAL_DEVICE_DISABLED) {
+             pr_warn("Warning: thermal function disabled.\n");
+             return;
+     }
+
+     thermal_zone_device_update(pzone->therm_dev);
+     pr_debug("db8500_thermal_work finished.\n");
+}
+
+static int __devinit db8500_thermal_probe(struct platform_device *pdev)
+{
+     struct db8500_thermal_zone *pzone = NULL;
+     struct db8500_thsens_platform_data *ptrips;
+     int low_irq, high_irq, ret = 0;
+     unsigned long dft_low, dft_high;
+
+     pzone = devm_kzalloc(&pdev->dev,
+                     sizeof(struct db8500_thermal_zone), GFP_KERNEL);
+     if (!pzone)
+             return -ENOMEM;
+
+     pzone->thsens_pdev = pdev;
+
+     low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
+     if (low_irq < 0) {
+             pr_err("Get IRQ_HOTMON_LOW failed.\n");
+             return low_irq;
+     }
+
+     ret = devm_request_threaded_irq(&pdev->dev, low_irq, NULL,
+             prcmu_low_irq_handler,
+             IRQF_NO_SUSPEND | IRQF_ONESHOT, "dbx500_temp_low", pzone);
+     if (ret < 0) {
+             pr_err("Failed to allocate temp low irq.\n");
+             return ret;
+     }
+
+     high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
+     if (high_irq < 0) {
+             pr_err("Get IRQ_HOTMON_HIGH failed.\n");
+             return high_irq;
+     }
+
+     ret = devm_request_threaded_irq(&pdev->dev, high_irq, NULL,
+             prcmu_high_irq_handler,
+             IRQF_NO_SUSPEND | IRQF_ONESHOT, "dbx500_temp_high", pzone);
+     if (ret < 0) {
+             pr_err("Failed to allocate temp high irq.\n");
+             return ret;
+     }
+
+     pzone->low_irq = low_irq;
+     pzone->high_irq = high_irq;
+
+     pzone->mode = THERMAL_DEVICE_DISABLED;
+
+     mutex_init(&pzone->th_lock);
+
+     INIT_WORK(&pzone->therm_work, db8500_thermal_work);
+
+     ptrips = pdev->dev.platform_data;
+     pzone->trip_tab = ptrips;
+
+     pzone->therm_dev = thermal_zone_device_register("db8500_thermal_zone",
+             ptrips->num_trips, 0, pzone, &thdev_ops, 0, 0);
+
+     if (IS_ERR(pzone->therm_dev)) {
+             pr_err("Failed to register thermal zone device\n");
+             return PTR_ERR(pzone->therm_dev);
+     }
+
+     dft_low = PRCMU_DEFAULT_LOW_TEMP;
+     dft_high = ptrips->trip_points[0].temp;
+
+     prcmu_stop_temp_sense();
+     prcmu_config_hotmon((u8)(dft_low/1000), (u8)(dft_high/1000));
+     prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
+
+     pzone->cur_index = 0;
+     pzone->cur_temp_pseudo = (dft_low + dft_high)/2;
+     pzone->trend = THERMAL_TREND_STABLE;

All the stuff from prcmu_stop_temp_sense() up to this line can race with
the irq handlers, I would suggest doing it before requesting the irqs.

quoted

+     pzone->mode = THERMAL_DEVICE_ENABLED;

Shouldn't this be protected by pzone->th_lock? Otherwise it should be
set before the thermal zone is registered.

quoted

+
+     platform_set_drvdata(pdev, pzone);
+
+     return 0;
+}
+
+static int __devexit db8500_thermal_remove(struct platform_device *pdev)
+{
+     struct db8500_thermal_zone *pzone;
+     pzone = platform_get_drvdata(pdev);
+
+     cancel_work_sync(&pzone->therm_work);
+
+     if (pzone->therm_dev)
+             thermal_zone_device_unregister(pzone->therm_dev);
+
+     return 0;
+}

mutex_destroy() should be called on pzone->th_lock

quoted

+
+static int db8500_thermal_suspend(struct platform_device *pdev,
+             pm_message_t state)
+{
+     struct db8500_thermal_zone *pzone;
+     pzone = platform_get_drvdata(pdev);
+
+     flush_work_sync(&pzone->therm_work);
+     prcmu_stop_temp_sense();
+
+     return 0;
+}
+
+static int db8500_thermal_resume(struct platform_device *pdev)
+{
+     struct db8500_thermal_zone *pzone;
+     struct db8500_thsens_platform_data *ptrips;
+     unsigned long dft_low, dft_high;
+
+     pzone = platform_get_drvdata(pdev);
+     ptrips = pzone->trip_tab;
+     dft_low = PRCMU_DEFAULT_LOW_TEMP;
+     dft_high = ptrips->trip_points[0].temp;
+
+     prcmu_config_hotmon((u8)(dft_low/1000), (u8)(dft_high/1000));
+     prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);

Shouldn't cur_index and cur_temp_pseudo be updated as well? You may want
to define a helper function with all the code shared by irq handlers
(both high and low), probe and resume.

No, they cannot be update because we don't know the actual current
temp[1] after short or long time suspend, everything goes as
beginning.

That's what I wanted to say, if everything is reset to a default value,
then cur_index and cur_temp should be reset too, as it's done in the
probe function. Otherwise you may have a current pseudo-temp and a
current index unrelated to how the hotmon is configured.

Yes, right.

quoted

If a helper function is introduced, it can be only used in probe and
resume I think, different and a bit complicated algorithm in irq
handlers.

I was thinking about a function which takes the new index and the new
low and high parameters, and updates cur_index and cur_pseudo_temp and
does the prcmu stuff. It seems to me this is (or should be) common to
all the 4 functions.

I misunderstood this helper will do all the updates, but algorithm of
cur_index is different everywhere.
If cur_index is calculated outside this new helper function, it works.
I will do that.

quoted

[1] due to lack of corresponding interface, search "TODO" in this file
to get more explanation.

--
Francesco