diff options
| author | Caesar Wang <wxt@rock-chips.com> | 2016-07-27 22:24:04 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-24 10:07:37 +0200 |
| commit | 5be0ba290063b1519f5c02ab2ef6b8788e91dfc7 (patch) | |
| tree | ecdc99827301a1c10183c8773ab2266bf6e673e2 /drivers | |
| parent | cb082cd5018c43860e2120e36292a1ffc6be2269 (diff) | |
iio: adc: rockchip_saradc: reset saradc controller before programming it
commit 543852af8e5902aee8f7c72c89e1513663e0f696 upstream.
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
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iio/adc/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/iio/adc/rockchip_saradc.c | 30 |
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 1e7aded53117..bda6bbe4479c 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -306,6 +306,7 @@ 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 9c311c1e1ac7..dffff64b5989 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; }; @@ -171,6 +174,16 @@ 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; @@ -199,6 +212,20 @@ 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(&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); @@ -233,6 +260,9 @@ 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. |