Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 625 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
new file mode 100644
index 000000000..31d2a3029
--- /dev/null
+++ b/drivers/input/touchscreen/ad7879.c
@@ -0,0 +1,625 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AD7879/AD7889 based touchscreen and GPIO driver
+ *
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * History:
+ * Copyright (c) 2005 David Brownell
+ * Copyright (c) 2006 Nokia Corporation
+ * Various changes: Imre Deak <imre.deak@nokia.com>
+ *
+ * Using code from:
+ *  - corgi_ts.c
+ *	Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *	Copyright (C) 2002 MontaVista Software
+ *	Copyright (C) 2004 Texas Instruments
+ *	Copyright (C) 2005 Dirk Behme
+ *  - ad7877.c
+ *	Copyright (C) 2006-2008 Analog Devices Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/gpio/driver.h>
+
+#include <linux/input/touchscreen.h>
+#include <linux/module.h>
+#include "ad7879.h"
+
+#define AD7879_REG_ZEROS		0
+#define AD7879_REG_CTRL1		1
+#define AD7879_REG_CTRL2		2
+#define AD7879_REG_CTRL3		3
+#define AD7879_REG_AUX1HIGH		4
+#define AD7879_REG_AUX1LOW		5
+#define AD7879_REG_TEMP1HIGH		6
+#define AD7879_REG_TEMP1LOW		7
+#define AD7879_REG_XPLUS		8
+#define AD7879_REG_YPLUS		9
+#define AD7879_REG_Z1			10
+#define AD7879_REG_Z2			11
+#define AD7879_REG_AUXVBAT		12
+#define AD7879_REG_TEMP			13
+#define AD7879_REG_REVID		14
+
+/* Control REG 1 */
+#define AD7879_TMR(x)			((x & 0xFF) << 0)
+#define AD7879_ACQ(x)			((x & 0x3) << 8)
+#define AD7879_MODE_NOC			(0 << 10)	/* Do not convert */
+#define AD7879_MODE_SCC			(1 << 10)	/* Single channel conversion */
+#define AD7879_MODE_SEQ0		(2 << 10)	/* Sequence 0 in Slave Mode */
+#define AD7879_MODE_SEQ1		(3 << 10)	/* Sequence 1 in Master Mode */
+#define AD7879_MODE_INT			(1 << 15)	/* PENIRQ disabled INT enabled */
+
+/* Control REG 2 */
+#define AD7879_FCD(x)			((x & 0x3) << 0)
+#define AD7879_RESET			(1 << 4)
+#define AD7879_MFS(x)			((x & 0x3) << 5)
+#define AD7879_AVG(x)			((x & 0x3) << 7)
+#define	AD7879_SER			(1 << 9)	/* non-differential */
+#define	AD7879_DFR			(0 << 9)	/* differential */
+#define AD7879_GPIOPOL			(1 << 10)
+#define AD7879_GPIODIR			(1 << 11)
+#define AD7879_GPIO_DATA		(1 << 12)
+#define AD7879_GPIO_EN			(1 << 13)
+#define AD7879_PM(x)			((x & 0x3) << 14)
+#define AD7879_PM_SHUTDOWN		(0)
+#define AD7879_PM_DYN			(1)
+#define AD7879_PM_FULLON		(2)
+
+/* Control REG 3 */
+#define AD7879_TEMPMASK_BIT		(1<<15)
+#define AD7879_AUXVBATMASK_BIT		(1<<14)
+#define AD7879_INTMODE_BIT		(1<<13)
+#define AD7879_GPIOALERTMASK_BIT	(1<<12)
+#define AD7879_AUXLOW_BIT		(1<<11)
+#define AD7879_AUXHIGH_BIT		(1<<10)
+#define AD7879_TEMPLOW_BIT		(1<<9)
+#define AD7879_TEMPHIGH_BIT		(1<<8)
+#define AD7879_YPLUS_BIT		(1<<7)
+#define AD7879_XPLUS_BIT		(1<<6)
+#define AD7879_Z1_BIT			(1<<5)
+#define AD7879_Z2_BIT			(1<<4)
+#define AD7879_AUX_BIT			(1<<3)
+#define AD7879_VBAT_BIT			(1<<2)
+#define AD7879_TEMP_BIT			(1<<1)
+
+enum {
+	AD7879_SEQ_YPOS  = 0,
+	AD7879_SEQ_XPOS  = 1,
+	AD7879_SEQ_Z1    = 2,
+	AD7879_SEQ_Z2    = 3,
+	AD7879_NR_SENSE  = 4,
+};
+
+#define	MAX_12BIT			((1<<12)-1)
+#define	TS_PEN_UP_TIMEOUT		msecs_to_jiffies(50)
+
+struct ad7879 {
+	struct regmap		*regmap;
+	struct device		*dev;
+	struct input_dev	*input;
+	struct timer_list	timer;
+#ifdef CONFIG_GPIOLIB
+	struct gpio_chip	gc;
+	struct mutex		mutex;
+#endif
+	unsigned int		irq;
+	bool			disabled;	/* P: input->mutex */
+	bool			suspended;	/* P: input->mutex */
+	bool			swap_xy;
+	u16			conversion_data[AD7879_NR_SENSE];
+	char			phys[32];
+	u8			first_conversion_delay;
+	u8			acquisition_time;
+	u8			averaging;
+	u8			pen_down_acc_interval;
+	u8			median;
+	u16			x_plate_ohms;
+	u16			cmd_crtl1;
+	u16			cmd_crtl2;
+	u16			cmd_crtl3;
+	int			x;
+	int			y;
+	int			Rt;
+};
+
+static int ad7879_read(struct ad7879 *ts, u8 reg)
+{
+	unsigned int val;
+	int error;
+
+	error = regmap_read(ts->regmap, reg, &val);
+	if (error) {
+		dev_err(ts->dev, "failed to read register %#02x: %d\n",
+			reg, error);
+		return error;
+	}
+
+	return val;
+}
+
+static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
+{
+	int error;
+
+	error = regmap_write(ts->regmap, reg, val);
+	if (error) {
+		dev_err(ts->dev,
+			"failed to write %#04x to register %#02x: %d\n",
+			val, reg, error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int ad7879_report(struct ad7879 *ts)
+{
+	struct input_dev *input_dev = ts->input;
+	unsigned Rt;
+	u16 x, y, z1, z2;
+
+	x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
+	y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
+	z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
+	z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
+
+	if (ts->swap_xy)
+		swap(x, y);
+
+	/*
+	 * The samples processed here are already preprocessed by the AD7879.
+	 * The preprocessing function consists of a median and an averaging
+	 * filter.  The combination of these two techniques provides a robust
+	 * solution, discarding the spurious noise in the signal and keeping
+	 * only the data of interest.  The size of both filters is
+	 * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
+	 * Other user-programmable conversion controls include variable
+	 * acquisition time, and first conversion delay. Up to 16 averages can
+	 * be taken per conversion.
+	 */
+
+	if (likely(x && z1)) {
+		/* compute touch pressure resistance using equation #1 */
+		Rt = (z2 - z1) * x * ts->x_plate_ohms;
+		Rt /= z1;
+		Rt = (Rt + 2047) >> 12;
+
+		/*
+		 * Sample found inconsistent, pressure is beyond
+		 * the maximum. Don't report it to user space.
+		 */
+		if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
+			return -EINVAL;
+
+		/*
+		 * Note that we delay reporting events by one sample.
+		 * This is done to avoid reporting last sample of the
+		 * touch sequence, which may be incomplete if finger
+		 * leaves the surface before last reading is taken.
+		 */
+		if (timer_pending(&ts->timer)) {
+			/* Touch continues */
+			input_report_key(input_dev, BTN_TOUCH, 1);
+			input_report_abs(input_dev, ABS_X, ts->x);
+			input_report_abs(input_dev, ABS_Y, ts->y);
+			input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
+			input_sync(input_dev);
+		}
+
+		ts->x = x;
+		ts->y = y;
+		ts->Rt = Rt;
+
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void ad7879_ts_event_release(struct ad7879 *ts)
+{
+	struct input_dev *input_dev = ts->input;
+
+	input_report_abs(input_dev, ABS_PRESSURE, 0);
+	input_report_key(input_dev, BTN_TOUCH, 0);
+	input_sync(input_dev);
+}
+
+static void ad7879_timer(struct timer_list *t)
+{
+	struct ad7879 *ts = timer_container_of(ts, t, timer);
+
+	ad7879_ts_event_release(ts);
+}
+
+static irqreturn_t ad7879_irq(int irq, void *handle)
+{
+	struct ad7879 *ts = handle;
+	int error;
+
+	error = regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
+				 ts->conversion_data, AD7879_NR_SENSE);
+	if (error)
+		dev_err_ratelimited(ts->dev, "failed to read %#02x: %d\n",
+				    AD7879_REG_XPLUS, error);
+	else if (!ad7879_report(ts))
+		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
+
+	return IRQ_HANDLED;
+}
+
+static void __ad7879_enable(struct ad7879 *ts)
+{
+	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
+	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
+
+	enable_irq(ts->irq);
+}
+
+static void __ad7879_disable(struct ad7879 *ts)
+{
+	u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
+		AD7879_PM(AD7879_PM_SHUTDOWN);
+	disable_irq(ts->irq);
+
+	if (timer_delete_sync(&ts->timer))
+		ad7879_ts_event_release(ts);
+
+	ad7879_write(ts, AD7879_REG_CTRL2, reg);
+}
+
+
+static int ad7879_open(struct input_dev *input)
+{
+	struct ad7879 *ts = input_get_drvdata(input);
+
+	/* protected by input->mutex */
+	if (!ts->disabled && !ts->suspended)
+		__ad7879_enable(ts);
+
+	return 0;
+}
+
+static void ad7879_close(struct input_dev *input)
+{
+	struct ad7879 *ts = input_get_drvdata(input);
+
+	/* protected by input->mutex */
+	if (!ts->disabled && !ts->suspended)
+		__ad7879_disable(ts);
+}
+
+static int __maybe_unused ad7879_suspend(struct device *dev)
+{
+	struct ad7879 *ts = dev_get_drvdata(dev);
+
+	guard(mutex)(&ts->input->mutex);
+
+	if (!ts->suspended && !ts->disabled && input_device_enabled(ts->input))
+		__ad7879_disable(ts);
+
+	ts->suspended = true;
+
+	return 0;
+}
+
+static int __maybe_unused ad7879_resume(struct device *dev)
+{
+	struct ad7879 *ts = dev_get_drvdata(dev);
+
+	guard(mutex)(&ts->input->mutex);
+
+	if (ts->suspended && !ts->disabled && input_device_enabled(ts->input))
+		__ad7879_enable(ts);
+
+	ts->suspended = false;
+
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
+EXPORT_SYMBOL(ad7879_pm_ops);
+
+static void ad7879_toggle(struct ad7879 *ts, bool disable)
+{
+	guard(mutex)(&ts->input->mutex);
+
+	if (!ts->suspended && input_device_enabled(ts->input)) {
+
+		if (disable) {
+			if (ts->disabled)
+				__ad7879_enable(ts);
+		} else {
+			if (!ts->disabled)
+				__ad7879_disable(ts);
+		}
+	}
+
+	ts->disabled = disable;
+}
+
+static ssize_t ad7879_disable_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct ad7879 *ts = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", ts->disabled);
+}
+
+static ssize_t ad7879_disable_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct ad7879 *ts = dev_get_drvdata(dev);
+	unsigned int val;
+	int error;
+
+	error = kstrtouint(buf, 10, &val);
+	if (error)
+		return error;
+
+	ad7879_toggle(ts, val);
+
+	return count;
+}
+
+static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
+
+static struct attribute *ad7879_attributes[] = {
+	&dev_attr_disable.attr,
+	NULL
+};
+
+static const struct attribute_group ad7879_attr_group = {
+	.attrs = ad7879_attributes,
+};
+
+const struct attribute_group *ad7879_groups[] = {
+	&ad7879_attr_group,
+	NULL
+};
+EXPORT_SYMBOL_GPL(ad7879_groups);
+
+#ifdef CONFIG_GPIOLIB
+static int ad7879_gpio_direction_input(struct gpio_chip *chip,
+					unsigned gpio)
+{
+	struct ad7879 *ts = gpiochip_get_data(chip);
+
+	guard(mutex)(&ts->mutex);
+
+	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
+	return ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+}
+
+static int ad7879_gpio_direction_output(struct gpio_chip *chip,
+					unsigned gpio, int level)
+{
+	struct ad7879 *ts = gpiochip_get_data(chip);
+
+	guard(mutex)(&ts->mutex);
+
+	ts->cmd_crtl2 &= ~AD7879_GPIODIR;
+	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
+	if (level)
+		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
+	else
+		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
+
+	return ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+}
+
+static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct ad7879 *ts = gpiochip_get_data(chip);
+	u16 val;
+
+	guard(mutex)(&ts->mutex);
+
+	val = ad7879_read(ts, AD7879_REG_CTRL2);
+	return !!(val & AD7879_GPIO_DATA);
+}
+
+static int ad7879_gpio_set_value(struct gpio_chip *chip, unsigned int gpio,
+				 int value)
+{
+	struct ad7879 *ts = gpiochip_get_data(chip);
+
+	guard(mutex)(&ts->mutex);
+
+	if (value)
+		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
+	else
+		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
+
+	return ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+}
+
+static int ad7879_gpio_add(struct ad7879 *ts)
+{
+	int ret = 0;
+
+	mutex_init(&ts->mutex);
+
+	/* Do not create a chip unless flagged for it */
+	if (!device_property_read_bool(ts->dev, "gpio-controller"))
+		return 0;
+
+	ts->gc.direction_input = ad7879_gpio_direction_input;
+	ts->gc.direction_output = ad7879_gpio_direction_output;
+	ts->gc.get = ad7879_gpio_get_value;
+	ts->gc.set = ad7879_gpio_set_value;
+	ts->gc.can_sleep = 1;
+	ts->gc.base = -1;
+	ts->gc.ngpio = 1;
+	ts->gc.label = "AD7879-GPIO";
+	ts->gc.owner = THIS_MODULE;
+	ts->gc.parent = ts->dev;
+
+	ret = devm_gpiochip_add_data(ts->dev, &ts->gc, ts);
+	if (ret)
+		dev_err(ts->dev, "failed to register gpio %d\n",
+			ts->gc.base);
+
+	return ret;
+}
+#else
+static int ad7879_gpio_add(struct ad7879 *ts)
+{
+	return 0;
+}
+#endif
+
+static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
+{
+	int err;
+	u32 tmp;
+
+	err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
+	if (err) {
+		dev_err(dev, "failed to get resistance-plate-x property\n");
+		return err;
+	}
+	ts->x_plate_ohms = (u16)tmp;
+
+	device_property_read_u8(dev, "adi,first-conversion-delay",
+				&ts->first_conversion_delay);
+	device_property_read_u8(dev, "adi,acquisition-time",
+				&ts->acquisition_time);
+	device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
+	device_property_read_u8(dev, "adi,averaging", &ts->averaging);
+	device_property_read_u8(dev, "adi,conversion-interval",
+				&ts->pen_down_acc_interval);
+
+	ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
+
+	return 0;
+}
+
+int ad7879_probe(struct device *dev, struct regmap *regmap,
+		 int irq, u16 bustype, u8 devid)
+{
+	struct ad7879 *ts;
+	struct input_dev *input_dev;
+	int err;
+	u16 revid;
+
+	if (irq <= 0) {
+		dev_err(dev, "No IRQ specified\n");
+		return -EINVAL;
+	}
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	err = ad7879_parse_dt(dev, ts);
+	if (err)
+		return err;
+
+	input_dev = devm_input_allocate_device(dev);
+	if (!input_dev) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	ts->dev = dev;
+	ts->input = input_dev;
+	ts->irq = irq;
+	ts->regmap = regmap;
+
+	timer_setup(&ts->timer, ad7879_timer, 0);
+	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
+
+	input_dev->name = "AD7879 Touchscreen";
+	input_dev->phys = ts->phys;
+	input_dev->dev.parent = dev;
+	input_dev->id.bustype = bustype;
+
+	input_dev->open = ad7879_open;
+	input_dev->close = ad7879_close;
+
+	input_set_drvdata(input_dev, ts);
+
+	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+
+	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+	input_set_capability(input_dev, EV_ABS, ABS_PRESSURE);
+	touchscreen_parse_properties(input_dev, false, NULL);
+	if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
+		dev_err(dev, "Touchscreen pressure is not specified\n");
+		return -EINVAL;
+	}
+
+	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
+	if (err < 0) {
+		dev_err(dev, "Failed to write %s\n", input_dev->name);
+		return err;
+	}
+
+	revid = ad7879_read(ts, AD7879_REG_REVID);
+	input_dev->id.product = (revid & 0xff);
+	input_dev->id.version = revid >> 8;
+	if (input_dev->id.product != devid) {
+		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
+			input_dev->name, devid, revid);
+		return -ENODEV;
+	}
+
+	ts->cmd_crtl3 = AD7879_YPLUS_BIT |
+			AD7879_XPLUS_BIT |
+			AD7879_Z2_BIT |
+			AD7879_Z1_BIT |
+			AD7879_TEMPMASK_BIT |
+			AD7879_AUXVBATMASK_BIT |
+			AD7879_GPIOALERTMASK_BIT;
+
+	ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
+			AD7879_AVG(ts->averaging) |
+			AD7879_MFS(ts->median) |
+			AD7879_FCD(ts->first_conversion_delay);
+
+	ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
+			AD7879_ACQ(ts->acquisition_time) |
+			AD7879_TMR(ts->pen_down_acc_interval);
+
+	err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					dev_name(dev), ts);
+	if (err) {
+		dev_err(dev, "Failed to request IRQ: %d\n", err);
+		return err;
+	}
+
+	__ad7879_disable(ts);
+
+	err = ad7879_gpio_add(ts);
+	if (err)
+		return err;
+
+	err = input_register_device(input_dev);
+	if (err)
+		return err;
+
+	dev_set_drvdata(dev, ts);
+
+	return 0;
+}
+EXPORT_SYMBOL(ad7879_probe);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
+MODULE_LICENSE("GPL");