[4/5] input: touchscreen: support Allwinner SoCs' touchscreen

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 8ecdc38..f16ce36 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1072,14 +1072,13 @@  config TOUCHSCREEN_STMPE
 config TOUCHSCREEN_SUN4I
 	tristate "Allwinner sun4i resistive touchscreen controller support"
 	depends on ARCH_SUNXI || COMPILE_TEST
-	depends on HWMON
-	depends on THERMAL || !THERMAL_OF
+	depends on SUNXI_ADC
 	help
-	  This selects support for the resistive touchscreen controller
-	  found on Allwinner sunxi SoCs.
+	  This selects support for the resistive touchscreen controller found
+	  on Allwinner SoCs (A10, A13, A31).
 
-	  To compile this driver as a module, choose M here: the
-	  module will be called sun4i-ts.
+	  To compile this driver as a module, choose M here: the module will be
+	  called sunxi-gpadc-ts.
 
 config TOUCHSCREEN_SUR40
 	tristate "Samsung SUR40 (Surface 2.0/PixelSense) touchscreen"
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index f42975e..bdc1889 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -65,7 +65,7 @@  obj-$(CONFIG_TOUCHSCREEN_PIXCIR)	+= pixcir_i2c_ts.o
 obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
 obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
 obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
-obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sun4i-ts.o
+obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sunxi-gpadc-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUR40)		+= sur40.o
 obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC)	+= ti_am335x_tsc.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)	+= touchit213.o
diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
deleted file mode 100644
index d07dd29..0000000
--- a/drivers/input/touchscreen/sun4i-ts.c
+++ /dev/null
@@ -1,419 +0,0 @@ 
-/*
- * Allwinner sunxi resistive touchscreen controller driver
- *
- * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com>
- *
- * The hwmon parts are based on work by Corentin LABBE which is:
- * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-/*
- * The sun4i-ts controller is capable of detecting a second touch, but when a
- * second touch is present then the accuracy becomes so bad the reported touch
- * location is not useable.
- *
- * The original android driver contains some complicated heuristics using the
- * aprox. distance between the 2 touches to see if the user is making a pinch
- * open / close movement, and then reports emulated multi-touch events around
- * the last touch coordinate (as the dual-touch coordinates are worthless).
- *
- * These kinds of heuristics are just asking for trouble (and don't belong
- * in the kernel). So this driver offers straight forward, reliable single
- * touch functionality only.
- *
- * s.a. A20 User Manual "1.15 TP" (Documentation/arm/sunxi/README)
- * (looks like the description in the A20 User Manual v1.3 is better
- * than the one in the A10 User Manual v.1.5)
- */
-
-#include <linux/err.h>
-#include <linux/hwmon.h>
-#include <linux/thermal.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/slab.h>
-
-#define TP_CTRL0		0x00
-#define TP_CTRL1		0x04
-#define TP_CTRL2		0x08
-#define TP_CTRL3		0x0c
-#define TP_INT_FIFOC		0x10
-#define TP_INT_FIFOS		0x14
-#define TP_TPR			0x18
-#define TP_CDAT			0x1c
-#define TEMP_DATA		0x20
-#define TP_DATA			0x24
-
-/* TP_CTRL0 bits */
-#define ADC_FIRST_DLY(x)	((x) << 24) /* 8 bits */
-#define ADC_FIRST_DLY_MODE(x)	((x) << 23)
-#define ADC_CLK_SEL(x)		((x) << 22)
-#define ADC_CLK_DIV(x)		((x) << 20) /* 3 bits */
-#define FS_DIV(x)		((x) << 16) /* 4 bits */
-#define T_ACQ(x)		((x) << 0) /* 16 bits */
-
-/* TP_CTRL1 bits */
-#define STYLUS_UP_DEBOUN(x)	((x) << 12) /* 8 bits */
-#define STYLUS_UP_DEBOUN_EN(x)	((x) << 9)
-#define TOUCH_PAN_CALI_EN(x)	((x) << 6)
-#define TP_DUAL_EN(x)		((x) << 5)
-#define TP_MODE_EN(x)		((x) << 4)
-#define TP_ADC_SELECT(x)	((x) << 3)
-#define ADC_CHAN_SELECT(x)	((x) << 0)  /* 3 bits */
-
-/* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
-#define SUN6I_TP_MODE_EN(x)	((x) << 5)
-
-/* TP_CTRL2 bits */
-#define TP_SENSITIVE_ADJUST(x)	((x) << 28) /* 4 bits */
-#define TP_MODE_SELECT(x)	((x) << 26) /* 2 bits */
-#define PRE_MEA_EN(x)		((x) << 24)
-#define PRE_MEA_THRE_CNT(x)	((x) << 0) /* 24 bits */
-
-/* TP_CTRL3 bits */
-#define FILTER_EN(x)		((x) << 2)
-#define FILTER_TYPE(x)		((x) << 0)  /* 2 bits */
-
-/* TP_INT_FIFOC irq and fifo mask / control bits */
-#define TEMP_IRQ_EN(x)		((x) << 18)
-#define OVERRUN_IRQ_EN(x)	((x) << 17)
-#define DATA_IRQ_EN(x)		((x) << 16)
-#define TP_DATA_XY_CHANGE(x)	((x) << 13)
-#define FIFO_TRIG(x)		((x) << 8)  /* 5 bits */
-#define DATA_DRQ_EN(x)		((x) << 7)
-#define FIFO_FLUSH(x)		((x) << 4)
-#define TP_UP_IRQ_EN(x)		((x) << 1)
-#define TP_DOWN_IRQ_EN(x)	((x) << 0)
-
-/* TP_INT_FIFOS irq and fifo status bits */
-#define TEMP_DATA_PENDING	BIT(18)
-#define FIFO_OVERRUN_PENDING	BIT(17)
-#define FIFO_DATA_PENDING	BIT(16)
-#define TP_IDLE_FLG		BIT(2)
-#define TP_UP_PENDING		BIT(1)
-#define TP_DOWN_PENDING		BIT(0)
-
-/* TP_TPR bits */
-#define TEMP_ENABLE(x)		((x) << 16)
-#define TEMP_PERIOD(x)		((x) << 0)  /* t = x * 256 * 16 / clkin */
-
-struct sun4i_ts_data {
-	struct device *dev;
-	struct input_dev *input;
-	void __iomem *base;
-	unsigned int irq;
-	bool ignore_fifo_data;
-	int temp_data;
-	int temp_offset;
-	int temp_step;
-};
-
-static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
-{
-	u32 x, y;
-
-	if (reg_val & FIFO_DATA_PENDING) {
-		x = readl(ts->base + TP_DATA);
-		y = readl(ts->base + TP_DATA);
-		/* The 1st location reported after an up event is unreliable */
-		if (!ts->ignore_fifo_data) {
-			input_report_abs(ts->input, ABS_X, x);
-			input_report_abs(ts->input, ABS_Y, y);
-			/*
-			 * The hardware has a separate down status bit, but
-			 * that gets set before we get the first location,
-			 * resulting in reporting a click on the old location.
-			 */
-			input_report_key(ts->input, BTN_TOUCH, 1);
-			input_sync(ts->input);
-		} else {
-			ts->ignore_fifo_data = false;
-		}
-	}
-
-	if (reg_val & TP_UP_PENDING) {
-		ts->ignore_fifo_data = true;
-		input_report_key(ts->input, BTN_TOUCH, 0);
-		input_sync(ts->input);
-	}
-}
-
-static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
-{
-	struct sun4i_ts_data *ts = dev_id;
-	u32 reg_val;
-
-	reg_val  = readl(ts->base + TP_INT_FIFOS);
-
-	if (reg_val & TEMP_DATA_PENDING)
-		ts->temp_data = readl(ts->base + TEMP_DATA);
-
-	if (ts->input)
-		sun4i_ts_irq_handle_input(ts, reg_val);
-
-	writel(reg_val, ts->base + TP_INT_FIFOS);
-
-	return IRQ_HANDLED;
-}
-
-static int sun4i_ts_open(struct input_dev *dev)
-{
-	struct sun4i_ts_data *ts = input_get_drvdata(dev);
-
-	/* Flush, set trig level to 1, enable temp, data and up irqs */
-	writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
-		TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
-
-	return 0;
-}
-
-static void sun4i_ts_close(struct input_dev *dev)
-{
-	struct sun4i_ts_data *ts = input_get_drvdata(dev);
-
-	/* Deactivate all input IRQs */
-	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
-}
-
-static int sun4i_get_temp(const struct sun4i_ts_data *ts, int *temp)
-{
-	/* No temp_data until the first irq */
-	if (ts->temp_data == -1)
-		return -EAGAIN;
-
-	*temp = ts->temp_data * ts->temp_step - ts->temp_offset;
-
-	return 0;
-}
-
-static int sun4i_get_tz_temp(void *data, int *temp)
-{
-	return sun4i_get_temp(data, temp);
-}
-
-static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
-	.get_temp = sun4i_get_tz_temp,
-};
-
-static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
-			 char *buf)
-{
-	struct sun4i_ts_data *ts = dev_get_drvdata(dev);
-	int temp;
-	int error;
-
-	error = sun4i_get_temp(ts, &temp);
-	if (error)
-		return error;
-
-	return sprintf(buf, "%d\n", temp);
-}
-
-static ssize_t show_temp_label(struct device *dev,
-			      struct device_attribute *devattr, char *buf)
-{
-	return sprintf(buf, "SoC temperature\n");
-}
-
-static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
-static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
-
-static struct attribute *sun4i_ts_attrs[] = {
-	&dev_attr_temp1_input.attr,
-	&dev_attr_temp1_label.attr,
-	NULL
-};
-ATTRIBUTE_GROUPS(sun4i_ts);
-
-static int sun4i_ts_probe(struct platform_device *pdev)
-{
-	struct sun4i_ts_data *ts;
-	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
-	struct device *hwmon;
-	int error;
-	u32 reg;
-	bool ts_attached;
-	u32 tp_sensitive_adjust = 15;
-	u32 filter_type = 1;
-
-	ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
-	if (!ts)
-		return -ENOMEM;
-
-	ts->dev = dev;
-	ts->ignore_fifo_data = true;
-	ts->temp_data = -1;
-	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
-		/* Allwinner SDK has temperature (C) = (value / 6) - 271 */
-		ts->temp_offset = 271000;
-		ts->temp_step = 167;
-	} else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
-		/*
-		 * The A10 temperature sensor has quite a wide spread, these
-		 * parameters are based on the averaging of the calibration
-		 * results of 4 completely different boards, with a spread of
-		 * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
-		 */
-		ts->temp_offset = 257000;
-		ts->temp_step = 133;
-	} else {
-		/*
-		 * The user manuals do not contain the formula for calculating
-		 * the temperature. The formula used here is from the AXP209,
-		 * which is designed by X-Powers, an affiliate of Allwinner:
-		 *
-		 *     temperature (C) = (value * 0.1) - 144.7
-		 *
-		 * Allwinner does not have any documentation whatsoever for
-		 * this hardware. Moreover, it is claimed that the sensor
-		 * is inaccurate and cannot work properly.
-		 */
-		ts->temp_offset = 144700;
-		ts->temp_step = 100;
-	}
-
-	ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
-	if (ts_attached) {
-		ts->input = devm_input_allocate_device(dev);
-		if (!ts->input)
-			return -ENOMEM;
-
-		ts->input->name = pdev->name;
-		ts->input->phys = "sun4i_ts/input0";
-		ts->input->open = sun4i_ts_open;
-		ts->input->close = sun4i_ts_close;
-		ts->input->id.bustype = BUS_HOST;
-		ts->input->id.vendor = 0x0001;
-		ts->input->id.product = 0x0001;
-		ts->input->id.version = 0x0100;
-		ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
-		__set_bit(BTN_TOUCH, ts->input->keybit);
-		input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
-		input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
-		input_set_drvdata(ts->input, ts);
-	}
-
-	ts->base = devm_ioremap_resource(dev,
-			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
-	if (IS_ERR(ts->base))
-		return PTR_ERR(ts->base);
-
-	ts->irq = platform_get_irq(pdev, 0);
-	error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
-	if (error)
-		return error;
-
-	/*
-	 * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
-	 * t_acq = clkin / (16 * 64)
-	 */
-	writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
-	       ts->base + TP_CTRL0);
-
-	/*
-	 * tp_sensitive_adjust is an optional property
-	 * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
-	 */
-	of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
-			     &tp_sensitive_adjust);
-	writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
-	       ts->base + TP_CTRL2);
-
-	/*
-	 * Enable median and averaging filter, optional property for
-	 * filter type.
-	 */
-	of_property_read_u32(np, "allwinner,filter-type", &filter_type);
-	writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);
-
-	/* Enable temperature measurement, period 1953 (2 seconds) */
-	writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
-
-	/*
-	 * Set stylus up debounce to aprox 10 ms, enable debounce, and
-	 * finally enable tp mode.
-	 */
-	reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
-	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
-		reg |= SUN6I_TP_MODE_EN(1);
-	else
-		reg |= TP_MODE_EN(1);
-	writel(reg, ts->base + TP_CTRL1);
-
-	/*
-	 * The thermal core does not register hwmon devices for DT-based
-	 * thermal zone sensors, such as this one.
-	 */
-	hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
-						       ts, sun4i_ts_groups);
-	if (IS_ERR(hwmon))
-		return PTR_ERR(hwmon);
-
-	devm_thermal_zone_of_sensor_register(ts->dev, 0, ts, &sun4i_ts_tz_ops);
-
-	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
-
-	if (ts_attached) {
-		error = input_register_device(ts->input);
-		if (error) {
-			writel(0, ts->base + TP_INT_FIFOC);
-			return error;
-		}
-	}
-
-	platform_set_drvdata(pdev, ts);
-	return 0;
-}
-
-static int sun4i_ts_remove(struct platform_device *pdev)
-{
-	struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
-
-	/* Explicit unregister to avoid open/close changing the imask later */
-	if (ts->input)
-		input_unregister_device(ts->input);
-
-	/* Deactivate all IRQs */
-	writel(0, ts->base + TP_INT_FIFOC);
-
-	return 0;
-}
-
-static const struct of_device_id sun4i_ts_of_match[] = {
-	{ .compatible = "allwinner,sun4i-a10-ts", },
-	{ .compatible = "allwinner,sun5i-a13-ts", },
-	{ .compatible = "allwinner,sun6i-a31-ts", },
-	{ /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
-
-static struct platform_driver sun4i_ts_driver = {
-	.driver = {
-		.name	= "sun4i-ts",
-		.of_match_table = of_match_ptr(sun4i_ts_of_match),
-	},
-	.probe	= sun4i_ts_probe,
-	.remove	= sun4i_ts_remove,
-};
-
-module_platform_driver(sun4i_ts_driver);
-
-MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
-MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
-MODULE_LICENSE("GPL");
diff --git a/drivers/input/touchscreen/sunxi-gpadc-ts.c b/drivers/input/touchscreen/sunxi-gpadc-ts.c
new file mode 100644
index 0000000..410d14f
--- /dev/null
+++ b/drivers/input/touchscreen/sunxi-gpadc-ts.c
@@ -0,0 +1,195 @@ 
+/* Touchscreen driver for Allwinner SoCs (A10, A13, A31) GPADC
+ *
+ * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/consumer.h>
+#include <linux/mfd/sunxi-gpadc-mfd.h>
+
+struct sunxi_gpadc_ts {
+	struct iio_cb_buffer	*buffer;
+	struct input_dev	*input;
+	struct platform_device	*pdev;
+	unsigned int		tp_up_irq;
+	bool			ignore_fifo_data;
+};
+
+static int sunxi_gpadc_ts_open(struct input_dev *dev)
+{
+	struct sunxi_gpadc_ts *info = input_get_drvdata(dev);
+	int ret;
+
+	ret = iio_channel_start_all_cb(info->buffer);
+	if (ret) {
+		dev_err(dev->dev.parent,
+			"failed to start iio channels with callback\n");
+		return ret;
+	}
+
+	enable_irq(info->tp_up_irq);
+
+	return 0;
+}
+
+static void sunxi_gpadc_ts_close(struct input_dev *dev)
+{
+	struct sunxi_gpadc_ts *info = input_get_drvdata(dev);
+
+	iio_channel_stop_all_cb(info->buffer);
+
+	disable_irq(info->tp_up_irq);
+}
+
+/*
+ * This function will be called by iio_push_to_buffers from another driver
+ * (namely sunxi-gpadc-iio). It will be passed the buffer filled with input
+ * values (X value then Y value) and the sunxi_gpadc_ts structure representing
+ * the device.
+ */
+static int sunxi_gpadc_ts_callback(const void *data, void *private)
+{
+	const struct sunxi_gpadc_buffer *buffer = data;
+	struct sunxi_gpadc_ts *info = private;
+	int i = 0;
+
+	/* Locations in the first buffer after an up event are unreliable */
+	if (info->ignore_fifo_data) {
+		info->ignore_fifo_data = false;
+		return 0;
+	}
+
+	while (i + 1 < buffer->buff_size) {
+		input_event(info->input, EV_ABS, ABS_X, buffer->buffer[i++]);
+		input_event(info->input, EV_ABS, ABS_Y, buffer->buffer[i++]);
+		input_event(info->input, EV_KEY, BTN_TOUCH, 1);
+		input_sync(info->input);
+	}
+
+	return 0;
+}
+
+static irqreturn_t sunxi_gpadc_tp_up_irq_handler(int irq, void *dev_id)
+{
+	struct sunxi_gpadc_ts *info = dev_id;
+
+	info->ignore_fifo_data = true;
+
+	input_event(info->input, EV_KEY, BTN_TOUCH, 0);
+	input_sync(info->input);
+
+	return IRQ_HANDLED;
+}
+
+static int sunxi_gpadc_ts_probe(struct platform_device *pdev)
+{
+	struct input_dev *input;
+	struct sunxi_gpadc_ts *info;
+	int ret, irq;
+	struct sunxi_gpadc_mfd_dev *sunxi_gpadc_mfd_dev;
+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->buffer = iio_channel_get_all_cb(&pdev->dev,
+					      &sunxi_gpadc_ts_callback,
+					      (void *)info);
+	if (IS_ERR(info->buffer)) {
+		if (PTR_ERR(info->buffer) == -ENODEV)
+			return -EPROBE_DEFER;
+		return PTR_ERR(info->buffer);
+	}
+
+	info->pdev = pdev;
+	info->input = input;
+	info->ignore_fifo_data = false;
+	platform_set_drvdata(pdev, info);
+
+	input->dev.parent = &pdev->dev;
+	input->name = "sunxi-gpadc-ts";
+	input->id.bustype = BUS_HOST;
+	input->open = sunxi_gpadc_ts_open;
+	input->close = sunxi_gpadc_ts_close;
+	__set_bit(EV_SYN, input->evbit);
+	input_set_capability(input, EV_KEY, BTN_TOUCH);
+	input_set_abs_params(input, ABS_X, 0, 4095, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, 4095, 0, 0);
+	input_set_drvdata(input, info);
+
+	irq = platform_get_irq_byname(pdev, "TP_UP_PENDING");
+	if (irq < 0) {
+		dev_err(&pdev->dev, "no TP_UP_PENDING interrupt registered\n");
+		ret = irq;
+		goto err;
+	}
+
+	sunxi_gpadc_mfd_dev = dev_get_drvdata(pdev->dev.parent);
+
+	irq = regmap_irq_get_virq(sunxi_gpadc_mfd_dev->regmap_irqc, irq);
+	ret = devm_request_any_context_irq(&pdev->dev, irq,
+					   sunxi_gpadc_tp_up_irq_handler, 0,
+					   "tp_up", info);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"could not request TP_UP_PENDING interrupt: %d\n", ret);
+		goto err;
+	}
+
+	info->tp_up_irq = irq;
+	disable_irq(irq);
+
+	ret = input_register_device(input);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	iio_channel_release_all_cb(info->buffer);
+
+	return ret;
+}
+
+static int sunxi_gpadc_ts_remove(struct platform_device *pdev)
+{
+	struct sunxi_gpadc_ts *info = platform_get_drvdata(pdev);
+
+	iio_channel_stop_all_cb(info->buffer);
+	iio_channel_release_all_cb(info->buffer);
+
+	disable_irq(info->tp_up_irq);
+
+	return 0;
+}
+
+static struct platform_driver sunxi_gpadc_ts_driver = {
+	.driver = {
+		.name = "sunxi-gpadc-ts",
+	},
+	.probe = sunxi_gpadc_ts_probe,
+	.remove = sunxi_gpadc_ts_remove,
+};
+
+module_platform_driver(sunxi_gpadc_ts_driver);
+
+MODULE_DESCRIPTION("Touchscreen driver for Allwinner SoCs (A10, A13, A31) GPADC");
+MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
+MODULE_LICENSE("GPL v2");