On Tue, Jul 26, 2016 at 08:13:12PM +0800, Caesar Wang wrote: > SARADC controller needs to be reset before programming it, otherwise > it will not function properly. > > Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx> > Cc: Jonathan Cameron <jic23@xxxxxxxxxx> > Cc: Heiko Stuebner <heiko@xxxxxxxxx> > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: linux-iio@xxxxxxxxxxxxxxx > Cc: linux-rockchip@xxxxxxxxxxxxxxxxxxx Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > --- > > Changes in v2: > - Make the reset as an optional property, since it should work > with old devicetrees as well. > > .../bindings/iio/adc/rockchip-saradc.txt | 7 +++++ > drivers/iio/adc/Kconfig | 1 + > drivers/iio/adc/rockchip_saradc.c | 31 ++++++++++++++++++++++ > 3 files changed, 39 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt > index bf99e2f..205593f 100644 > --- a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt > +++ b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt > @@ -16,6 +16,11 @@ Required properties: > - vref-supply: The regulator supply ADC reference voltage. > - #io-channel-cells: Should be 1, see ../iio-bindings.txt > > +Optional properties: > +- resets: Must contain an entry for each entry in reset-names if need support > + this option. See ../reset/reset.txt for details. > +- reset-names: Must include the name "saradc-apb". > + > Example: > saradc: saradc@2006c000 { > compatible = "rockchip,saradc"; > @@ -23,6 +28,8 @@ Example: > interrupts = <GIC_SPI 26 IRQ_TYPE_LEVEL_HIGH>; > clocks = <&cru SCLK_SARADC>, <&cru PCLK_SARADC>; > clock-names = "saradc", "apb_pclk"; > + resets = <&cru SRST_SARADC>; > + reset-names = "saradc-apb"; > #io-channel-cells = <1>; > vref-supply = <&vcc18>; > }; > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 1de31bd..7675772 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -389,6 +389,7 @@ config QCOM_SPMI_VADC > config ROCKCHIP_SARADC > tristate "Rockchip SARADC driver" > depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST) > + depends on RESET_CONTROLLER > help > Say yes here to build support for the SARADC found in SoCs from > Rockchip. > diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c > index f9ad6c2..dc1379f 100644 > --- a/drivers/iio/adc/rockchip_saradc.c > +++ b/drivers/iio/adc/rockchip_saradc.c > @@ -21,6 +21,8 @@ > #include <linux/of_device.h> > #include <linux/clk.h> > #include <linux/completion.h> > +#include <linux/delay.h> > +#include <linux/reset.h> > #include <linux/regulator/consumer.h> > #include <linux/iio/iio.h> > > @@ -53,6 +55,7 @@ struct rockchip_saradc { > struct clk *clk; > struct completion completion; > struct regulator *vref; > + struct reset_control *reset; > const struct rockchip_saradc_data *data; > u16 last_val; > }; > @@ -190,6 +193,16 @@ static const struct of_device_id rockchip_saradc_match[] = { > }; > MODULE_DEVICE_TABLE(of, rockchip_saradc_match); > > +/** > + * Reset SARADC Controller. > + */ > +static void rockchip_saradc_reset_controller(struct reset_control *reset) > +{ > + reset_control_assert(reset); > + usleep_range(10, 20); > + reset_control_deassert(reset); > +} > + > static int rockchip_saradc_probe(struct platform_device *pdev) > { > struct rockchip_saradc *info = NULL; > @@ -218,6 +231,21 @@ static int rockchip_saradc_probe(struct platform_device *pdev) > if (IS_ERR(info->regs)) > return PTR_ERR(info->regs); > > + /* > + * The reset should be an optional property, as it should work > + * with old devicetrees as well > + */ > + info->reset = devm_reset_control_get_optional(&pdev->dev, > + "saradc-apb"); > + if (IS_ERR(info->reset)) { > + ret = PTR_ERR(info->reset); > + if (ret != -ENOENT) > + return ret; > + > + dev_dbg(&pdev->dev, "no reset control found\n"); > + info->reset = NULL; > + } > + > init_completion(&info->completion); > > irq = platform_get_irq(pdev, 0); > @@ -252,6 +280,9 @@ static int rockchip_saradc_probe(struct platform_device *pdev) > return PTR_ERR(info->vref); > } > > + if (info->reset) > + rockchip_saradc_reset_controller(info->reset); > + > /* > * Use a default value for the converter clock. > * This may become user-configurable in the future. > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html