drivers/input/keyboard/sun4i-lradc-keys.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Allwinner sun4i low res adc attached tablet keys driver
  *
  * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
  */

 /*
  * Allwinnner sunxi SoCs have a lradc which is specifically designed to have
  * various (tablet) keys (ie home, back, search, etc). attached to it using
  * a resistor network. This driver is for the keys on such boards.
  *
  * There are 2 channels, currently this driver only supports channel 0 since
  * 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>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #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
 #define LRADC_INTC		0x04
 #define LRADC_INTS		0x08
 #define LRADC_DATA0		0x0c
 #define LRADC_DATA1		0x10

 /* LRADC_CTRL bits */
 #define FIRST_CONVERT_DLY(x)	((x) << 24) /* 8 bits */
 #define CHAN_SELECT(x)		((x) << 22) /* 2 bits */
 #define CONTINUE_TIME_SEL(x)	((x) << 16) /* 4 bits */
 #define KEY_MODE_SEL(x)		((x) << 12) /* 2 bits */
 #define LEVELA_B_CNT(x)		((x) << 8)  /* 4 bits */
 #define HOLD_KEY_EN(x)		((x) << 7)
 #define HOLD_EN(x)		((x) << 6)
 #define LEVELB_VOL(x)		((x) << 4)  /* 2 bits */
 #define SAMPLE_RATE(x)		((x) << 2)  /* 2 bits */
 #define ENABLE(x)		((x) << 0)

 /* LRADC_INTC and LRADC_INTS bits */
 #define CHAN1_KEYUP_IRQ		BIT(12)
 #define CHAN1_ALRDY_HOLD_IRQ	BIT(11)
 #define CHAN1_HOLD_IRQ		BIT(10)
 #define	CHAN1_KEYDOWN_IRQ	BIT(9)
 #define CHAN1_DATA_IRQ		BIT(8)
 #define CHAN0_KEYUP_IRQ		BIT(4)
 #define CHAN0_ALRDY_HOLD_IRQ	BIT(3)
 #define CHAN0_HOLD_IRQ		BIT(2)
 #define	CHAN0_KEYDOWN_IRQ	BIT(1)
 #define CHAN0_DATA_IRQ		BIT(0)

 /* 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 = {
 	.divisor_numerator = 2,
 	.divisor_denominator = 3
 };

 static const struct lradc_variant r_lradc_variant_a83t = {
 	.divisor_numerator = 3,
 	.divisor_denominator = 4
 };

 static const struct lradc_variant lradc_variant_r329 = {
 	.divisor_numerator = 3,
 	.divisor_denominator = 4,
 	.has_clock_reset = true,
 };

 struct sun4i_lradc_keymap {
 	u32 voltage;
 	u32 keycode;
 };

 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;
 	u32 chan0_map_count;
 	u32 chan0_keycode;
 	u32 vref;
 };

 static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
 {
 	struct sun4i_lradc_data *lradc = dev_id;
 	u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;

 	ints  = readl(lradc->base + LRADC_INTS);

 	/*
 	 * lradc supports only one keypress at a time, release does not give
 	 * any info as to which key was released, so we cache the keycode.
 	 */

 	if (ints & CHAN0_KEYUP_IRQ) {
 		input_report_key(lradc->input, lradc->chan0_keycode, 0);
 		lradc->chan0_keycode = 0;
 	}

 	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
 		val = readl(lradc->base + LRADC_DATA0) & 0x3f;
 		voltage = val * lradc->vref / 63;

 		for (i = 0; i < lradc->chan0_map_count; i++) {
 			diff = abs(lradc->chan0_map[i].voltage - voltage);
 			if (diff < closest) {
 				closest = diff;
 				keycode = lradc->chan0_map[i].keycode;
 			}
 		}

 		lradc->chan0_keycode = keycode;
 		input_report_key(lradc->input, lradc->chan0_keycode, 1);
 	}

 	input_sync(lradc->input);

 	writel(ints, lradc->base + LRADC_INTS);

 	return IRQ_HANDLED;
 }

 static int sun4i_lradc_open(struct input_dev *dev)
 {
 	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
 	int error;

 	error = regulator_enable(lradc->vref_supply);
 	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;
 	/*
 	 * Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to
 	 * stabilize on press, wait (1 + 1) * 4 ms for key release
 	 */
 	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
 		SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL);

 	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)
 {
 	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);

 	/* Disable lradc, leave other settings unchanged */
 	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
 		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);
 }

 static int sun4i_lradc_load_dt_keymap(struct device *dev,
 				      struct sun4i_lradc_data *lradc)
 {
 	struct device_node *np, *pp;
 	int i;
 	int error;

 	np = dev->of_node;
 	if (!np)
 		return -EINVAL;

 	lradc->chan0_map_count = of_get_child_count(np);
 	if (lradc->chan0_map_count == 0) {
 		dev_err(dev, "keymap is missing in device tree\n");
 		return -EINVAL;
 	}

 	lradc->chan0_map = devm_kmalloc_array(dev, lradc->chan0_map_count,
 					      sizeof(struct sun4i_lradc_keymap),
 					      GFP_KERNEL);
 	if (!lradc->chan0_map)
 		return -ENOMEM;

 	i = 0;
 	for_each_child_of_node(np, pp) {
 		struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];
 		u32 channel;

 		error = of_property_read_u32(pp, "channel", &channel);
 		if (error || channel != 0) {
 			dev_err(dev, "%pOFn: Inval channel prop\n", pp);
 			of_node_put(pp);
 			return -EINVAL;
 		}

 		error = of_property_read_u32(pp, "voltage", &map->voltage);
 		if (error) {
 			dev_err(dev, "%pOFn: Inval voltage prop\n", pp);
 			of_node_put(pp);
 			return -EINVAL;
 		}

 		error = of_property_read_u32(pp, "linux,code", &map->keycode);
 		if (error) {
 			dev_err(dev, "%pOFn: Inval linux,code prop\n", pp);
 			of_node_put(pp);
 			return -EINVAL;
 		}

 		i++;
 	}

 	return 0;
 }

 static int sun4i_lradc_probe(struct platform_device *pdev)
 {
 	struct sun4i_lradc_data *lradc;
 	struct device *dev = &pdev->dev;
 	int error, i, irq;

 	lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
 	if (!lradc)
 		return -ENOMEM;

 	error = sun4i_lradc_load_dt_keymap(dev, lradc);
 	if (error)
 		return error;

 	lradc->variant = of_device_get_match_data(&pdev->dev);
 	if (!lradc->variant) {
 		dev_err(&pdev->dev, "Missing sun4i-a10-lradc-keys variant\n");
 		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);

 	lradc->dev = dev;
 	lradc->input = devm_input_allocate_device(dev);
 	if (!lradc->input)
 		return -ENOMEM;

 	lradc->input->name = pdev->name;
 	lradc->input->phys = "sun4i_lradc/input0";
 	lradc->input->open = sun4i_lradc_open;
 	lradc->input->close = sun4i_lradc_close;
 	lradc->input->id.bustype = BUS_HOST;
 	lradc->input->id.vendor = 0x0001;
 	lradc->input->id.product = 0x0001;
 	lradc->input->id.version = 0x0100;

 	__set_bit(EV_KEY, lradc->input->evbit);
 	for (i = 0; i < lradc->chan0_map_count; i++)
 		__set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);

 	input_set_drvdata(lradc->input, lradc);

 	lradc->base = devm_ioremap_resource(dev,
 			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
 	if (IS_ERR(lradc->base))
 		return PTR_ERR(lradc->base);

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	error = devm_request_irq(dev, irq, sun4i_lradc_irq, 0,
 				 "sun4i-a10-lradc-keys", lradc);
 	if (error)
 		return error;

 	error = input_register_device(lradc->input);
 	if (error)
 		return error;

 	if (device_property_read_bool(dev, "wakeup-source")) {
 		error = dev_pm_set_wake_irq(dev, irq);
 		if (error)
 			dev_warn(dev,
 				 "Failed to set IRQ %d as a wake IRQ: %d\n",
 				 irq, error);
 		else
 			device_set_wakeup_capable(dev, true);
 	}

 	return 0;
 }

 static const struct of_device_id sun4i_lradc_of_match[] = {
 	{ .compatible = "allwinner,sun4i-a10-lradc-keys",
 		.data = &lradc_variant_a10 },
 	{ .compatible = "allwinner,sun8i-a83t-r-lradc",
 		.data = &r_lradc_variant_a83t },
 	{ .compatible = "allwinner,sun50i-r329-lradc",
 		.data = &lradc_variant_r329 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);

 static struct platform_driver sun4i_lradc_driver = {
 	.driver = {
 		.name	= "sun4i-a10-lradc-keys",
 		.of_match_table = of_match_ptr(sun4i_lradc_of_match),
 	},
 	.probe	= sun4i_lradc_probe,
 };

 module_platform_driver(sun4i_lradc_driver);

 MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Allwinner sun4i low res adc attached tablet keys driver
	*
	* Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
	*/

	/*
	* Allwinnner sunxi SoCs have a lradc which is specifically designed to have
	* various (tablet) keys (ie home, back, search, etc). attached to it using
	* a resistor network. This driver is for the keys on such boards.
	*
	* There are 2 channels, currently this driver only supports channel 0 since
	* 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>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of_platform.h>
	#include <linux/platform_device.h>
	#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
	#define LRADC_INTC 0x04
	#define LRADC_INTS 0x08
	#define LRADC_DATA0 0x0c
	#define LRADC_DATA1 0x10

	/* LRADC_CTRL bits */
	#define FIRST_CONVERT_DLY(x) ((x) << 24) /* 8 bits */
	#define CHAN_SELECT(x) ((x) << 22) /* 2 bits */
	#define CONTINUE_TIME_SEL(x) ((x) << 16) /* 4 bits */
	#define KEY_MODE_SEL(x) ((x) << 12) /* 2 bits */
	#define LEVELA_B_CNT(x) ((x) << 8) /* 4 bits */
	#define HOLD_KEY_EN(x) ((x) << 7)
	#define HOLD_EN(x) ((x) << 6)
	#define LEVELB_VOL(x) ((x) << 4) /* 2 bits */
	#define SAMPLE_RATE(x) ((x) << 2) /* 2 bits */
	#define ENABLE(x) ((x) << 0)

	/* LRADC_INTC and LRADC_INTS bits */
	#define CHAN1_KEYUP_IRQ BIT(12)
	#define CHAN1_ALRDY_HOLD_IRQ BIT(11)
	#define CHAN1_HOLD_IRQ BIT(10)
	#define CHAN1_KEYDOWN_IRQ BIT(9)
	#define CHAN1_DATA_IRQ BIT(8)
	#define CHAN0_KEYUP_IRQ BIT(4)
	#define CHAN0_ALRDY_HOLD_IRQ BIT(3)
	#define CHAN0_HOLD_IRQ BIT(2)
	#define CHAN0_KEYDOWN_IRQ BIT(1)
	#define CHAN0_DATA_IRQ BIT(0)

	/* 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 = {
	.divisor_numerator = 2,
	.divisor_denominator = 3
	};

	static const struct lradc_variant r_lradc_variant_a83t = {
	.divisor_numerator = 3,
	.divisor_denominator = 4
	};

	static const struct lradc_variant lradc_variant_r329 = {
	.divisor_numerator = 3,
	.divisor_denominator = 4,
	.has_clock_reset = true,
	};

	struct sun4i_lradc_keymap {
	u32 voltage;
	u32 keycode;
	};

	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;
	u32 chan0_map_count;
	u32 chan0_keycode;
	u32 vref;
	};

	static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
	{
	struct sun4i_lradc_data *lradc = dev_id;
	u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;

	ints = readl(lradc->base + LRADC_INTS);

	/*
	* lradc supports only one keypress at a time, release does not give
	* any info as to which key was released, so we cache the keycode.
	*/

	if (ints & CHAN0_KEYUP_IRQ) {
	input_report_key(lradc->input, lradc->chan0_keycode, 0);
	lradc->chan0_keycode = 0;
	}

	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
	val = readl(lradc->base + LRADC_DATA0) & 0x3f;
	voltage = val * lradc->vref / 63;

	for (i = 0; i < lradc->chan0_map_count; i++) {
	diff = abs(lradc->chan0_map[i].voltage - voltage);
	if (diff < closest) {
	closest = diff;
	keycode = lradc->chan0_map[i].keycode;
	}
	}

	lradc->chan0_keycode = keycode;
	input_report_key(lradc->input, lradc->chan0_keycode, 1);
	}

	input_sync(lradc->input);

	writel(ints, lradc->base + LRADC_INTS);

	return IRQ_HANDLED;
	}

	static int sun4i_lradc_open(struct input_dev *dev)
	{
	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
	int error;

	error = regulator_enable(lradc->vref_supply);
	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;
	/*
	* Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to
	* stabilize on press, wait (1 + 1) * 4 ms for key release
	*/
	writel(FIRST_CONVERT_DLY(2) \| LEVELA_B_CNT(1) \| HOLD_EN(1) \|
	SAMPLE_RATE(0) \| ENABLE(1), lradc->base + LRADC_CTRL);

	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)
	{
	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);

	/* Disable lradc, leave other settings unchanged */
	writel(FIRST_CONVERT_DLY(2) \| LEVELA_B_CNT(1) \| HOLD_EN(1) \|
	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);
	}

	static int sun4i_lradc_load_dt_keymap(struct device *dev,
	struct sun4i_lradc_data *lradc)
	{
	struct device_node np, pp;
	int i;
	int error;

	np = dev->of_node;
	if (!np)
	return -EINVAL;

	lradc->chan0_map_count = of_get_child_count(np);
	if (lradc->chan0_map_count == 0) {
	dev_err(dev, "keymap is missing in device tree\n");
	return -EINVAL;
	}

	lradc->chan0_map = devm_kmalloc_array(dev, lradc->chan0_map_count,
	sizeof(struct sun4i_lradc_keymap),
	GFP_KERNEL);
	if (!lradc->chan0_map)
	return -ENOMEM;

	i = 0;
	for_each_child_of_node(np, pp) {
	struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];
	u32 channel;

	error = of_property_read_u32(pp, "channel", &channel);
	if (error \|\| channel != 0) {
	dev_err(dev, "%pOFn: Inval channel prop\n", pp);
	of_node_put(pp);
	return -EINVAL;
	}

	error = of_property_read_u32(pp, "voltage", &map->voltage);
	if (error) {
	dev_err(dev, "%pOFn: Inval voltage prop\n", pp);
	of_node_put(pp);
	return -EINVAL;
	}

	error = of_property_read_u32(pp, "linux,code", &map->keycode);
	if (error) {
	dev_err(dev, "%pOFn: Inval linux,code prop\n", pp);
	of_node_put(pp);
	return -EINVAL;
	}

	i++;
	}

	return 0;
	}

	static int sun4i_lradc_probe(struct platform_device *pdev)
	{
	struct sun4i_lradc_data *lradc;
	struct device *dev = &pdev->dev;
	int error, i, irq;

	lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
	if (!lradc)
	return -ENOMEM;

	error = sun4i_lradc_load_dt_keymap(dev, lradc);
	if (error)
	return error;

	lradc->variant = of_device_get_match_data(&pdev->dev);
	if (!lradc->variant) {
	dev_err(&pdev->dev, "Missing sun4i-a10-lradc-keys variant\n");
	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);

	lradc->dev = dev;
	lradc->input = devm_input_allocate_device(dev);
	if (!lradc->input)
	return -ENOMEM;

	lradc->input->name = pdev->name;
	lradc->input->phys = "sun4i_lradc/input0";
	lradc->input->open = sun4i_lradc_open;
	lradc->input->close = sun4i_lradc_close;
	lradc->input->id.bustype = BUS_HOST;
	lradc->input->id.vendor = 0x0001;
	lradc->input->id.product = 0x0001;
	lradc->input->id.version = 0x0100;

	__set_bit(EV_KEY, lradc->input->evbit);
	for (i = 0; i < lradc->chan0_map_count; i++)
	__set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);

	input_set_drvdata(lradc->input, lradc);

	lradc->base = devm_ioremap_resource(dev,
	platform_get_resource(pdev, IORESOURCE_MEM, 0));
	if (IS_ERR(lradc->base))
	return PTR_ERR(lradc->base);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	error = devm_request_irq(dev, irq, sun4i_lradc_irq, 0,
	"sun4i-a10-lradc-keys", lradc);
	if (error)
	return error;

	error = input_register_device(lradc->input);
	if (error)
	return error;

	if (device_property_read_bool(dev, "wakeup-source")) {
	error = dev_pm_set_wake_irq(dev, irq);
	if (error)
	dev_warn(dev,
	"Failed to set IRQ %d as a wake IRQ: %d\n",
	irq, error);
	else
	device_set_wakeup_capable(dev, true);
	}

	return 0;
	}

	static const struct of_device_id sun4i_lradc_of_match[] = {
	{ .compatible = "allwinner,sun4i-a10-lradc-keys",
	.data = &lradc_variant_a10 },
	{ .compatible = "allwinner,sun8i-a83t-r-lradc",
	.data = &r_lradc_variant_a83t },
	{ .compatible = "allwinner,sun50i-r329-lradc",
	.data = &lradc_variant_r329 },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);

	static struct platform_driver sun4i_lradc_driver = {
	.driver = {
	.name = "sun4i-a10-lradc-keys",
	.of_match_table = of_match_ptr(sun4i_lradc_of_match),
	},
	.probe = sun4i_lradc_probe,
	};

	module_platform_driver(sun4i_lradc_driver);

	MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
	MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
	MODULE_LICENSE("GPL");