Re: [PATCH v2 2/3] Input: sun4i-lradc-keys: Add optional clock/reset support

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne četrtek, 14. april 2022 ob 02:23:47 CEST je Samuel Holland napisal(a):
> Until the R329, the LRADC hardware was always active. Now it requires
> enabling a clock gate and deasserting a reset line. Add support for this
> variant of the hardware.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> ---
> 
> Changes in v2:
>  - Guard the code with a flag instead of using "_optional" variants.
> 
>  drivers/input/keyboard/sun4i-lradc-keys.c | 33 +++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c
> b/drivers/input/keyboard/sun4i-lradc-keys.c index
> 4a796bed48ac..5630334a6c09 100644
> --- a/drivers/input/keyboard/sun4i-lradc-keys.c
> +++ b/drivers/input/keyboard/sun4i-lradc-keys.c
> @@ -14,6 +14,7 @@
>   * there are no boards known to use channel 1.
>   */
> 
> +#include <linux/clk.h>
>  #include <linux/err.h>
>  #include <linux/init.h>
>  #include <linux/input.h>
> @@ -23,6 +24,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
> 
>  #define LRADC_CTRL		0x00
> @@ -58,10 +60,12 @@
>  /* struct lradc_variant - Describe sun4i-a10-lradc-keys hardware variant
>   * @divisor_numerator:		The numerator of lradc Vref internally 
divisor
>   * @divisor_denominator:	The denominator of lradc Vref internally 
divisor
> + * @has_clock_reset:		If the binding requires a clock and reset
>   */
>  struct lradc_variant {
>  	u8 divisor_numerator;
>  	u8 divisor_denominator;
> +	bool has_clock_reset;
>  };
> 
>  static const struct lradc_variant lradc_variant_a10 = {
> @@ -83,6 +87,8 @@ struct sun4i_lradc_data {
>  	struct device *dev;
>  	struct input_dev *input;
>  	void __iomem *base;
> +	struct clk *clk;
> +	struct reset_control *reset;
>  	struct regulator *vref_supply;
>  	struct sun4i_lradc_keymap *chan0_map;
>  	const struct lradc_variant *variant;
> @@ -140,6 +146,14 @@ static int sun4i_lradc_open(struct input_dev *dev)
>  	if (error)
>  		return error;
> 
> +	error = reset_control_deassert(lradc->reset);
> +	if (error)
> +		goto err_disable_reg;
> +
> +	error = clk_prepare_enable(lradc->clk);
> +	if (error)
> +		goto err_assert_reset;
> +
>  	lradc->vref = regulator_get_voltage(lradc->vref_supply) *
>  		      lradc->variant->divisor_numerator /
>  		      lradc->variant->divisor_denominator;
> @@ -153,6 +167,13 @@ static int sun4i_lradc_open(struct input_dev *dev)
>  	writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + 
LRADC_INTC);
> 
>  	return 0;
> +
> +err_assert_reset:
> +	reset_control_assert(lradc->reset);
> +err_disable_reg:
> +	regulator_disable(lradc->vref_supply);
> +
> +	return error;
>  }
> 
>  static void sun4i_lradc_close(struct input_dev *dev)
> @@ -164,6 +185,8 @@ static void sun4i_lradc_close(struct input_dev *dev)
>  		SAMPLE_RATE(2), lradc->base + LRADC_CTRL);
>  	writel(0, lradc->base + LRADC_INTC);
> 
> +	clk_disable_unprepare(lradc->clk);
> +	reset_control_assert(lradc->reset);
>  	regulator_disable(lradc->vref_supply);
>  }
> 
> @@ -243,6 +266,16 @@ static int sun4i_lradc_probe(struct platform_device
> *pdev) return -EINVAL;
>  	}
> 
> +	if (lradc->variant->has_clock_reset) {
> +		lradc->clk = devm_clk_get(dev, NULL);
> +		if (IS_ERR(lradc->clk))
> +			return PTR_ERR(lradc->clk);
> +
> +		lradc->reset = devm_reset_control_get_exclusive(dev, 
NULL);
> +		if (IS_ERR(lradc->reset))
> +			return PTR_ERR(lradc->reset);
> +	}
> +
>  	lradc->vref_supply = devm_regulator_get(dev, "vref");
>  	if (IS_ERR(lradc->vref_supply))
>  		return PTR_ERR(lradc->vref_supply);