Re: [PATCH v2] thermal: exynos: add special clock support
From: Abhilash Kesavan
Date: Wed Nov 26 2014 - 10:04:27 EST
Hi Eduardo,
On Wed, Nov 26, 2014 at 8:15 PM, Eduardo Valentin <edubezval@xxxxxxxxx> wrote:
>
> Abhilash,
>
> On Wed, Nov 26, 2014 at 06:21:10AM +0530, Abhilash Kesavan wrote:
>> Exynos7 has a special clock required for the functional operation
>> of the TMU that is not present in earlier SoCs. Add support for
>> this clock and update the binding documentation.
>>
>> Signed-off-by: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx>
>> ---
>> Changes since v1:
>> - Added a per-soc flag to indicate the presence of special clock
>> - Changed the name of special clock from "tmu_sclk" to "sclk"
>> - Fixed the error handling for sclk
>>
>> Tested on 5420 and 5800 based chromebooks, no change in existing behavior.
>>
>> .../devicetree/bindings/thermal/exynos-thermal.txt | 3 ++
>> drivers/thermal/samsung/exynos_tmu.c | 31 ++++++++++++++++----
>> 2 files changed, 29 insertions(+), 5 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> index ae738f5..acf4705 100644
>> --- a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> +++ b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> @@ -32,10 +32,13 @@
>> - clocks : The main clocks for TMU device
>> -- 1. operational clock for TMU channel
>> -- 2. optional clock to access the shared registers of TMU channel
>> + -- 3. optional special clock for functional operation
>> - clock-names : Thermal system clock name
>> -- "tmu_apbif" operational clock for current TMU channel
>> -- "tmu_triminfo_apbif" clock to access the shared triminfo register
>> for current TMU channel
>> + -- "sclk" clock for functional operation of the current TMU
>> + channel
>> - vtmu-supply: This entry is optional and provides the regulator node supplying
>> voltage to TMU. If needed this entry can be placed inside
>> board/platform specific dts file.
>> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
>> index d44d91d..8ed8409 100644
>> --- a/drivers/thermal/samsung/exynos_tmu.c
>> +++ b/drivers/thermal/samsung/exynos_tmu.c
>> @@ -123,11 +123,14 @@
>> * @base: base address of the single instance of the TMU controller.
>> * @base_second: base address of the common registers of the TMU controller.
>> * @irq: irq number of the TMU controller.
>> + * @needs_sclk: SoC specific flag indicating that sclk is required for
>> + functional operation of the TMU controller.
>> * @soc: id of the SOC type.
>> * @irq_work: pointer to the irq work structure.
>> * @lock: lock to implement synchronization.
>> * @clk: pointer to the clock structure.
>> * @clk_sec: pointer to the clock structure for accessing the base_second.
>> + * @sclk: pointer to the clock structure for accessing the tmu special clock.
>> * @temp_error1: fused value of the first point trim.
>> * @temp_error2: fused value of the second point trim.
>> * @regulator: pointer to the TMU regulator structure.
>> @@ -144,10 +147,11 @@ struct exynos_tmu_data {
>> void __iomem *base;
>> void __iomem *base_second;
>> int irq;
>> + bool needs_sclk;
>> enum soc_type soc;
>> struct work_struct irq_work;
>> struct mutex lock;
>> - struct clk *clk, *clk_sec;
>> + struct clk *clk, *clk_sec, *sclk;
>> u8 temp_error1, temp_error2;
>> struct regulator *regulator;
>> struct thermal_sensor_conf *reg_conf;
>> @@ -883,10 +887,24 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>> goto err_clk_sec;
>> }
>>
>> + if (data->needs_sclk) {
>
> Based on the trend we see from Bartlomiej's and Lukasz' works, you
> should be asking for SoC version, not adding a flag. Can you please
> crosscheck with them?
I planned to populate this flag as true for Exynos7 in
exynos_map_dt_data() where other soc specific methods are being setup.
Bartlomiej/Lukasz can you kindly comment on if you would prefer the
check to be based on the SoC version.
Regards,
Abhilash
>
> Cheers,
>
> Eduardo Valentin
>
>> + data->sclk = devm_clk_get(&pdev->dev, "sclk");
>> + if (IS_ERR(data->sclk)) {
>> + dev_err(&pdev->dev, "Failed to get sclk\n");
>> + goto err_clk;
>> + } else {
>> + ret = clk_prepare_enable(data->sclk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Failed to enable sclk\n");
>> + goto err_clk;
>> + }
>> + }
>> + }
>> +
>> ret = exynos_tmu_initialize(pdev);
>> if (ret) {
>> dev_err(&pdev->dev, "Failed to initialize TMU\n");
>> - goto err_clk;
>> + goto err_sclk;
>> }
>>
>> exynos_tmu_control(pdev, true);
>> @@ -896,7 +914,7 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>> sizeof(struct thermal_sensor_conf), GFP_KERNEL);
>> if (!sensor_conf) {
>> ret = -ENOMEM;
>> - goto err_clk;
>> + goto err_sclk;
>> }
>> sprintf(sensor_conf->name, "therm_zone%d", data->id);
>> sensor_conf->read_temperature = (int (*)(void *))exynos_tmu_read;
>> @@ -928,7 +946,7 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>> ret = exynos_register_thermal(sensor_conf);
>> if (ret) {
>> dev_err(&pdev->dev, "Failed to register thermal interface\n");
>> - goto err_clk;
>> + goto err_sclk;
>> }
>> data->reg_conf = sensor_conf;
>>
>> @@ -936,10 +954,12 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>> IRQF_TRIGGER_RISING | IRQF_SHARED, dev_name(&pdev->dev), data);
>> if (ret) {
>> dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
>> - goto err_clk;
>> + goto err_sclk;
>> }
>>
>> return 0;
>> +err_sclk:
>> + clk_disable_unprepare(data->sclk);
>> err_clk:
>> clk_unprepare(data->clk);
>> err_clk_sec:
>> @@ -956,6 +976,7 @@ static int exynos_tmu_remove(struct platform_device *pdev)
>>
>> exynos_tmu_control(pdev, false);
>>
>> + clk_disable_unprepare(data->sclk);
>> clk_unprepare(data->clk);
>> if (!IS_ERR(data->clk_sec))
>> clk_unprepare(data->clk_sec);
>> --
>> 1.7.9.5
>>
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