Re: [PATCH] iio: adc: exynos_adc: Control special clock of ADC to support Exynos3250 ADC

Chanwoo Choi
2014-04-14T00:58:24Z

Hi Jonathan,

On 04/12/2014 04:49 PM, Jonathan Cameron wrote:
>
>
> On April 11, 2014 11:45:42 PM GMT+01:00, "최찬우" <cwchoi00@gmail.com> wrote:
>> Hi Bartlomiej,
>>
>> On Fri, Apr 11, 2014 at 6:41 PM, Bartlomiej Zolnierkiewicz
>> <b.zolnierkie@samsung.com> wrote:
>>>
>>> Hi,
>>>
>>> On Friday, April 11, 2014 11:00:40 AM Chanwoo Choi wrote:
>>>> This patch control special clock for ADC in Exynos series's FSYS
>> block.
>>>
>>> s/control/controls/
>>
>> I'll fix it.
>>
>>>
>>>> If special clock of ADC is registerd on clock list of common clk
>> framework,
>>>> Exynos ADC drvier have to control this clock.
>>>
>>> s/drvier/driver/
>>
>> I'll fix it.
>>
>>>
>>>> Exynos3250/Exynos4/Exynos5 has 'adc' clock as following:
>>>> - 'adc' clock: bus clock for ADC
>>>>
>>>> Exynos3250 has additional 'sclk_tsadc' clock as following:
>>>> - 'sclk_tsadc' clock: special clock for ADC which provide clock to
>> internal ADC
>>>>
>>>> Exynos 4210/4212/4412 and Exynos5250/5420 has not included
>> 'sclk_tsadc' clock
>>>> in FSYS_BLK. But, Exynos3250 based on Cortex-A7 has only included
>> 'sclk_tsadc'
>>>> clock in FSYS_BLK.
>>>>
>>>> Cc: Jonathan Cameron <jic23@kernel.org>
>>>> Cc: Kukjin Kim <kgene.kim@samsung.com>
>>>> Cc: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
>>>> Cc: linux-iio@vger.kernel.org
>>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>>>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>>>> ---
>>>> drivers/iio/adc/exynos_adc.c | 13 +++++++++++++
>>>> 1 file changed, 13 insertions(+)
>>>>
>>>> diff --git a/drivers/iio/adc/exynos_adc.c
>> b/drivers/iio/adc/exynos_adc.c
>>>> index d25b262..4cd1975 100644
>>>> --- a/drivers/iio/adc/exynos_adc.c
>>>> +++ b/drivers/iio/adc/exynos_adc.c
>>>> @@ -88,6 +88,7 @@ struct exynos_adc {
>>>> void __iomem *regs;
>>>> void __iomem *enable_reg;
>>>> struct clk *clk;
>>>> + struct clk *sclk;
>>>> unsigned int irq;
>>>> struct regulator *vdd;
>>>>
>>>> @@ -308,6 +309,13 @@ static int exynos_adc_probe(struct
>> platform_device *pdev)
>>>> goto err_irq;
>>>> }
>>>>
>>>> + info->sclk = devm_clk_get(&pdev->dev, "sclk_tsadc");
>>>> + if (IS_ERR(info->sclk)) {
>>>> + dev_warn(&pdev->dev, "failed getting sclk clock, err =
>> %ld\n",
>>>> +
>> PTR_ERR(info->sclk));
>>>> + info->sclk = NULL;
>>>> + }
>>>> +
>>>> info->vdd = devm_regulator_get(&pdev->dev, "vdd");
>>>> if (IS_ERR(info->vdd)) {
>>>> dev_err(&pdev->dev, "failed getting regulator, err =
>> %ld\n",
>>>> @@ -341,6 +349,7 @@ static int exynos_adc_probe(struct
>> platform_device *pdev)
>>>> goto err_iio_dev;
>>>>
>>>> clk_prepare_enable(info->clk);
>>>> + clk_prepare_enable(info->sclk);
>>>>
>>>> exynos_adc_hw_init(info);
>>>>
>>>> @@ -357,6 +366,7 @@ err_of_populate:
>>>> exynos_adc_remove_devices);
>>>> regulator_disable(info->vdd);
>>>> clk_disable_unprepare(info->clk);
>>>> + clk_disable_unprepare(info->sclk);
>>>
>>> Please disable clocks in the reverse of order in which they were
>> enabled.
>>
>> Is it necessary? I don't think that.
> It is probably not a bug but it is more obviously correct in the reverse order so that is how it should be done!

OK, I'll fix it on next posting(v2). Thanks.

Best Regards,
Chanwoo Choi