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

From: Tomasz Figa
Date: Fri Apr 11 2014 - 06:56:41 EST


Hi,

On 11.04.2014 11:41, Bartlomiej Zolnierkiewicz 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/

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/

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@xxxxxxxxxx>
Cc: Kukjin Kim <kgene.kim@xxxxxxxxxxx>
Cc: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx>
Cc: linux-iio@xxxxxxxxxxxxxxx
Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/iio/adc/exynos_adc.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

This change alters DT bindings for Exynos ADC, so documentation must be modified appropriately.


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;
+ }
+

Is there any reason why we should have a warning on SoCs which don't have this clock? I think this clock should be acquired only for affected SoCs.

Best regards,
Tomasz
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