On 2016年07月26日 11:22, Guenter Roeck wrote:
On 07/25/2016 07:51 PM, Caesar Wang wrote:
Hi Guenter,
Thanks for fixing it.
On 2016年07月26日 03:39, Guenter Roeck wrote:
If the ADC is read for the first time, the caller gets a timeout error,
and the kernel log shows
read channel() error: -110
The ADC may be enabled on boot, and needs to be explicitly disabled
for a read sequence to work (otherwise there is no completion
interrupt).
Disaple it explicitly in the probe function.
Fixes: 44d6f2ef94f9 ("iio: adc: add driver for Rockchip saradc")
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/iio/adc/rockchip_saradc.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/iio/adc/rockchip_saradc.c
b/drivers/iio/adc/rockchip_saradc.c
index f9ad6c2d6821..6aa3271d86b5 100644
--- a/drivers/iio/adc/rockchip_saradc.c
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -280,6 +280,9 @@ static int rockchip_saradc_probe(struct
platform_device *pdev)
goto err_pclk;
}
+ /* Make sure ADC is disabled */
+ writel_relaxed(0, info->regs + SARADC_CTRL);
I think we should reset the saradc controller.
Since make sure the reset value is 0 and loader-->kernel may even
cause harm, as my experience on tsadc.
(drivers/thermal/rockchip_thermal.c)
e.g.:
/**
* Reset SARADC Controller, reset all saradc registers.
*/
static void rockchip_saradc_reset_controller(struct reset_control
*reset)
{
reset_control_assert(reset);
usleep_range(10, 20);
reset_control_deassert(reset);
}
..probe()
{
...
rockchip_saradc_reset_controller();
...
}
Ok, I'll give it a try.
I posted it on https://patchwork.kernel.org/patch/9247661/
Guenter
-
Caesar
+
platform_set_drvdata(pdev, indio_dev);
indio_dev->name = dev_name(&pdev->dev);
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--
caesar wang | software engineer | wxt@xxxxxxxxxxxxx
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