[PATCH] thermal: exynos: add optional sclk support
Abhilash Kesavan
kesavan.abhilash at gmail.com
Sat Nov 22 21:32:51 PST 2014
Hi Chanwoo,
On Sun, Nov 23, 2014 at 10:21 AM, Chanwoo Choi <cwchoi00 at gmail.com> wrote:
> Hi Abhilash,
>
> On Sat, Nov 22, 2014 at 4:45 PM, Abhilash Kesavan <a.kesavan at samsung.com> 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 optional clock and update the binding documentation.
>>
>
> Latest Exynos SoC needs the special clocks. It is different part from
> previous Exynos SoC.
> Exynos3250 must need the special clock for ADC IP like this patch.
> So, I sent the smiliar patch[1] to support SCLK as following and merged it.
>
> [1] https://lkml.org/lkml/2014/7/21/734
Thanks for the link.
>
> So, I suggest you that Exynos would use the similar method to support
> special clock
> on all of IPs for Exynos SoC.
>
>> Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
>> ---
>> This patch was earlier part of the series adding TMU support for
>> Exynos7 [1]. It has been split out as it does not impact the on-going
>> consolidation in the exynos tmu driver and can be considered
>> independently.
>>
>> .../devicetree/bindings/thermal/exynos-thermal.txt | 3 +++
>> drivers/thermal/samsung/exynos_tmu.c | 27 ++++++++++++++++----
>> 2 files changed, 25 insertions(+), 5 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> index ae738f5..2393eac 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
>> + -- "tmu_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..6627937 100644
>> --- a/drivers/thermal/samsung/exynos_tmu.c
>> +++ b/drivers/thermal/samsung/exynos_tmu.c
>> @@ -128,6 +128,7 @@
>> * @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 clk.
>> * @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.
>> @@ -147,7 +148,7 @@ struct exynos_tmu_data {
>> 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 +884,21 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>> goto err_clk_sec;
>> }
>>
>> + data->sclk = devm_clk_get(&pdev->dev, "tmu_sclk");
>> + if (IS_ERR(data->sclk)) {
>> + dev_err(&pdev->dev, "Failed to get optional special clock\n");
>
> Exynos4, Exynos3250 etc may show error message always. I think It is not proper.
> I recommend that you use additional 'needs_sclk' field. If 'needs_sclk' is true,
> tmu driver will get the special clock of tmu without error message.
OK, I'll add a per-soc field to check for sclk availability.
>
> Also, How about just 'sclk' instead of 'tmu_sclk'?
> I discussed the name of 'sclk' with Arnd Bergmann on following patch[2]
Sure, I'll use 'sclk' instead of 'tmu_sclk'.
>
> [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/273557.html
>
>> + } else {
>> + ret = clk_prepare_enable(data->sclk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Failed to enable special clock\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 +908,7 @@ 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 +940,7 @@ 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 +948,13 @@ 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:
>> + if (!IS_ERR(data->sclk))
>> + clk_disable_unprepare(data->sclk);
>
> I think IS_ERROR don't be necessary because
> clk_disalbe_unprepare check the NULL pointer of clock pointer.
>
>> err_clk:
>> clk_unprepare(data->clk);
>> err_clk_sec:
>> @@ -956,6 +971,8 @@ static int exynos_tmu_remove(struct platform_device *pdev)
>>
>> exynos_tmu_control(pdev, false);
>>
>> + if (!IS_ERR(data->sclk))
>> + clk_disable_unprepare(data->sclk);
>
> ditto.
Will fix.
Thanks for the review.
Regards,
Abhilash
>
> Best Regards,
> Chanwoo Choi
>
>> clk_unprepare(data->clk);
>> if (!IS_ERR(data->clk_sec))
>> clk_unprepare(data->clk_sec);
>> --
>> 1.7.9.5
>>
>>
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