Commit ac2d5b43 authored by Samuel Holland's avatar Samuel Holland Committed by Dmitry Torokhov
Browse files

Input: sun4i-lradc-keys - add optional clock/reset support 



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: default avatarSamuel Holland <samuel@sholland.org>
Acked-by: default avatarJernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220414002349.24332-2-samuel@sholland.org


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 61f19f67

drivers/input/keyboard/sun4i-lradc-keys.c

+33 −0
Original line number Diff line number Diff line
@@ -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>
@@ -25,6 +26,7 @@ 
#include <linux/pm_wakeirq.h>

#include <linux/pm_wakeup.h>

#include <linux/regulator/consumer.h>

#include <linux/reset.h>

#include <linux/slab.h>



#define LRADC_CTRL		0x00
@@ -60,10 +62,12 @@ 
/* 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 = {
@@ -85,6 +89,8 @@ 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;
@@ -142,6 +148,14 @@ 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;
@@ -155,6 +169,13 @@ 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)
@@ -166,6 +187,8 @@ 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);

}
@@ -244,6 +267,16 @@ 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);