Messages in this thread | | | Date | Tue, 26 Jul 2016 10:51:34 +0800 | From | Caesar Wang <> | Subject | Re: [PATCH] iio: adc: rockchip_saradc: Explicitly disable ADC on probe |
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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@roeck-us.net> > --- > 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(); ... }
- Caesar
> + > platform_set_drvdata(pdev, indio_dev); > > indio_dev->name = dev_name(&pdev->dev);
-- caesar wang | software engineer | wxt@rock-chip.com
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