Re: [PATCH v2] thermal: exynos: add special clock support

[Abhilash Kesavan]

Hi Eduardo,

On Wed, Nov 26, 2014 at 8:44 PM, Eduardo Valentin <edubezval@xxxxxxxxx> wrote:
> Abhilash,
>
> On Wed, Nov 26, 2014 at 08:34:19PM +0530, Abhilash Kesavan wrote:
>> 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.
>
> Well, that I wouldn't expect different, otherwise how your code is
> supposed to work, right?

yes :)

>
>>
>> Bartlomiej/Lukasz can you kindly comment on if you would prefer the
>> check to be based on the SoC version.
>>
>
>
> Have a look on how Bartz has removed the flag based code in my -linus
> branch. Here is an example:
> https://git.kernel.org/cgit/linux/kernel/git/evalenti/linux-soc-thermal.git/commit/?h=linus&id=ef3f80fc7f79c32a1b015afcbffce2a2630011a4

OK, I see what you mean. I'll wait for Bartlomiej and Lukasz to weigh
in as well. If they are in favor of using the SoC version then I will
fold this into the patch adding support for Exynos7 (to be posted
after all of Lukasz' patches are in)

Thanks,
Abhilash
>
>> 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
>> >>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/