| Message ID | 1469513510-1516-1-git-send-email-wxt@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 26 Jul 2016 14:11:47 +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@rock-chips.com> > Cc: Jonathan Cameron <jic23@kernel.org> > Cc: Heiko Stuebner <heiko@sntech.de> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: linux-iio@vger.kernel.org > Cc: linux-rockchip@lists.infradead.org > --- > > diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c > index f9ad6c2..2f0e110 100644 > --- a/drivers/iio/adc/rockchip_saradc.c > +++ b/drivers/iio/adc/rockchip_saradc.c > @@ -218,6 +231,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev) > if (IS_ERR(info->regs)) > return PTR_ERR(info->regs); > > + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); > + if (IS_ERR(info->reset)) { > + ret = PTR_ERR(info->reset); > + dev_err(&pdev->dev, "failed to get saradc reset: %d\n", ret); > + return ret; > + } Does this need to handle ENOENT so as to avoid failing with old device tree blobs?
Am Dienstag, 26. Juli 2016, 14:11:47 schrieb Caesar Wang: > SARADC controller needs to be reset before programming it, otherwise > it will not function properly. > > Signed-off-by: Caesar Wang <wxt@rock-chips.com> > Cc: Jonathan Cameron <jic23@kernel.org> > Cc: Heiko Stuebner <heiko@sntech.de> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: linux-iio@vger.kernel.org > Cc: linux-rockchip@lists.infradead.org > --- > > .../bindings/iio/adc/rockchip-saradc.txt | 5 +++++ > drivers/iio/adc/Kconfig | 1 + > drivers/iio/adc/rockchip_saradc.c | 22 > ++++++++++++++++++++++ 3 files changed, 28 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt > b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt index > bf99e2f..d2258be 100644 > --- a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt > +++ b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt > @@ -13,6 +13,9 @@ Required properties: > - clocks: Must contain an entry for each entry in clock-names. > - clock-names: Shall be "saradc" for the converter-clock, and "apb_pclk" > for the peripheral clock. > +- resets: Must contain an entry for each entry in reset-names. > + See ../reset/reset.txt for details. > +- reset-names: Must include the name "saradc-apb". as pointed out by John, this should be an optional property, as it should work with old devicetrees as well.
On 2016年07月26日 17:00, John Keeping wrote: > On Tue, 26 Jul 2016 14:11:47 +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@rock-chips.com> >> Cc: Jonathan Cameron <jic23@kernel.org> >> Cc: Heiko Stuebner <heiko@sntech.de> >> Cc: Rob Herring <robh+dt@kernel.org> >> Cc: linux-iio@vger.kernel.org >> Cc: linux-rockchip@lists.infradead.org >> --- >> >> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c >> index f9ad6c2..2f0e110 100644 >> --- a/drivers/iio/adc/rockchip_saradc.c >> +++ b/drivers/iio/adc/rockchip_saradc.c >> @@ -218,6 +231,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev) >> if (IS_ERR(info->regs)) >> return PTR_ERR(info->regs); >> >> + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); >> + if (IS_ERR(info->reset)) { >> + ret = PTR_ERR(info->reset); >> + dev_err(&pdev->dev, "failed to get saradc reset: %d\n", ret); >> + return ret; >> + } > Does this need to handle ENOENT so as to avoid failing with old device > tree blobs? I'm no sure why we have to support the old device tree, We can apply this series patches if we need to support the reset property. --- Maybe, I can follow you suggestion to handle the ENOENT, as following: + /* + * The reset should be an optional property, as it should work + * with old devicetrees as well + */ + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); + if (IS_ERR(info->reset)) { + if (PTR_ERR(info->reset) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + return ret; + } + dev_dbg(&pdev->dev, "no reset control found\n"); + info->reset = NULL; + } ... + if (info->reset) + rockchip_saradc_reset_controller(info->reset); + How about it? - Caesar > > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip
On Tue, 26 Jul 2016 18:49:56 +0800, Caesar Wang wrote: > > On 2016年07月26日 17:00, John Keeping wrote: > > On Tue, 26 Jul 2016 14:11:47 +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@rock-chips.com> > >> Cc: Jonathan Cameron <jic23@kernel.org> > >> Cc: Heiko Stuebner <heiko@sntech.de> > >> Cc: Rob Herring <robh+dt@kernel.org> > >> Cc: linux-iio@vger.kernel.org > >> Cc: linux-rockchip@lists.infradead.org > >> --- > >> > >> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c > >> index f9ad6c2..2f0e110 100644 > >> --- a/drivers/iio/adc/rockchip_saradc.c > >> +++ b/drivers/iio/adc/rockchip_saradc.c > >> @@ -218,6 +231,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev) > >> if (IS_ERR(info->regs)) > >> return PTR_ERR(info->regs); > >> > >> + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); > >> + if (IS_ERR(info->reset)) { > >> + ret = PTR_ERR(info->reset); > >> + dev_err(&pdev->dev, "failed to get saradc reset: %d\n", ret); > >> + return ret; > >> + } > > Does this need to handle ENOENT so as to avoid failing with old device > > tree blobs? > > I'm no sure why we have to support the old device tree, > We can apply this series patches if we need to support the reset property. > --- > > Maybe, I can follow you suggestion to handle the ENOENT, as following: > > + /* > + * The reset should be an optional property, as it should work > + * with old devicetrees as well > + */ > + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); > + if (IS_ERR(info->reset)) { > + if (PTR_ERR(info->reset) == -EPROBE_DEFER) { > + ret = -EPROBE_DEFER; > + return ret; > + } > + dev_dbg(&pdev->dev, "no reset control found\n"); > + info->reset = NULL; > + } > ... > > How about it? I think it's better to handle ENOENT specifically, we still want to fail if some other errors like EINVAL is returned. Something like this, perhaps? 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; } Although I do wonder if a devm_reset_control_get_optional() helper would be useful (this isn't the first time I've seen reset control added to existing drivers).
diff --git a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt index bf99e2f..d2258be 100644 --- a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt +++ b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt @@ -13,6 +13,9 @@ Required properties: - clocks: Must contain an entry for each entry in clock-names. - clock-names: Shall be "saradc" for the converter-clock, and "apb_pclk" for the peripheral clock. +- resets: Must contain an entry for each entry in reset-names. + See ../reset/reset.txt for details. +- reset-names: Must include the name "saradc-apb". - vref-supply: The regulator supply ADC reference voltage. - #io-channel-cells: Should be 1, see ../iio-bindings.txt @@ -23,6 +26,8 @@ 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..2f0e110 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 +231,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev) if (IS_ERR(info->regs)) return PTR_ERR(info->regs); + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); + if (IS_ERR(info->reset)) { + ret = PTR_ERR(info->reset); + dev_err(&pdev->dev, "failed to get saradc reset: %d\n", ret); + return ret; + } + init_completion(&info->completion); irq = platform_get_irq(pdev, 0); @@ -252,6 +272,8 @@ static int rockchip_saradc_probe(struct platform_device *pdev) return PTR_ERR(info->vref); } + rockchip_saradc_reset_controller(info->reset); + /* * Use a default value for the converter clock. * This may become user-configurable in the future.
SARADC controller needs to be reset before programming it, otherwise it will not function properly. Signed-off-by: Caesar Wang <wxt@rock-chips.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-iio@vger.kernel.org Cc: linux-rockchip@lists.infradead.org --- .../bindings/iio/adc/rockchip-saradc.txt | 5 +++++ drivers/iio/adc/Kconfig | 1 + drivers/iio/adc/rockchip_saradc.c | 22 ++++++++++++++++++++++ 3 files changed, 28 insertions(+)