1 files changed, 628 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/tsc200x-core.c b/drivers/input/touchscreen/tsc200x-core.c
new file mode 100644
index 000000000..72c7258b9
--- /dev/null
+++ b/drivers/input/touchscreen/tsc200x-core.c
@@ -0,0 +1,628 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TSC2004/TSC2005 touchscreen driver core
+ *
+ * Copyright (C) 2006-2010 Nokia Corporation
+ * Copyright (C) 2015 QWERTY Embedded Design
+ * Copyright (C) 2015 EMAC Inc.
+ *
+ * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
+ * based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/input/touchscreen.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
+#include "tsc200x-core.h"
+
+/*
+ * The touchscreen interface operates as follows:
+ *
+ * 1) Pen is pressed against the touchscreen.
+ * 2) TSC200X performs AD conversion.
+ * 3) After the conversion is done TSC200X drives DAV line down.
+ * 4) GPIO IRQ is received and tsc200x_irq_thread() is scheduled.
+ * 5) tsc200x_irq_thread() queues up a transfer to fetch the x, y, z1, z2
+ *    values.
+ * 6) tsc200x_irq_thread() reports coordinates to input layer and sets up
+ *    tsc200x_penup_timer() to be called after TSC200X_PENUP_TIME_MS (40ms).
+ * 7) When the penup timer expires, there have not been touch or DAV interrupts
+ *    during the last 40ms which means the pen has been lifted.
+ *
+ * ESD recovery via a hardware reset is done if the TSC200X doesn't respond
+ * after a configurable period (in ms) of activity. If esd_timeout is 0, the
+ * watchdog is disabled.
+ */
+
+static const struct regmap_range tsc200x_writable_ranges[] = {
+	regmap_reg_range(TSC200X_REG_AUX_HIGH, TSC200X_REG_CFR2),
+};
+
+static const struct regmap_access_table tsc200x_writable_table = {
+	.yes_ranges = tsc200x_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(tsc200x_writable_ranges),
+};
+
+const struct regmap_config tsc200x_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.reg_stride = 0x08,
+	.max_register = 0x78,
+	.read_flag_mask = TSC200X_REG_READ,
+	.write_flag_mask = TSC200X_REG_PND0,
+	.wr_table = &tsc200x_writable_table,
+	.use_single_read = true,
+	.use_single_write = true,
+};
+EXPORT_SYMBOL_GPL(tsc200x_regmap_config);
+
+struct tsc200x_data {
+	u16 x;
+	u16 y;
+	u16 z1;
+	u16 z2;
+} __packed;
+#define TSC200X_DATA_REGS 4
+
+struct tsc200x {
+	struct device           *dev;
+	struct regmap		*regmap;
+	__u16                   bustype;
+
+	struct input_dev	*idev;
+	char			phys[32];
+
+	struct mutex		mutex;
+
+	/* raw copy of previous x,y,z */
+	int			in_x;
+	int			in_y;
+	int                     in_z1;
+	int			in_z2;
+
+	struct touchscreen_properties prop;
+
+	spinlock_t		lock;
+	struct timer_list	penup_timer;
+
+	unsigned int		esd_timeout;
+	struct delayed_work	esd_work;
+	unsigned long		last_valid_interrupt;
+
+	unsigned int		x_plate_ohm;
+
+	bool			opened;
+	bool			suspended;
+
+	bool			pen_down;
+
+	struct regulator	*vio;
+
+	struct gpio_desc	*reset_gpio;
+	int			(*tsc200x_cmd)(struct device *dev, u8 cmd);
+	int			irq;
+};
+
+static void tsc200x_update_pen_state(struct tsc200x *ts,
+				     int x, int y, int pressure)
+{
+	if (pressure) {
+		touchscreen_report_pos(ts->idev, &ts->prop, x, y, false);
+		input_report_abs(ts->idev, ABS_PRESSURE, pressure);
+		if (!ts->pen_down) {
+			input_report_key(ts->idev, BTN_TOUCH, !!pressure);
+			ts->pen_down = true;
+		}
+	} else {
+		input_report_abs(ts->idev, ABS_PRESSURE, 0);
+		if (ts->pen_down) {
+			input_report_key(ts->idev, BTN_TOUCH, 0);
+			ts->pen_down = false;
+		}
+	}
+	input_sync(ts->idev);
+	dev_dbg(ts->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
+		pressure);
+}
+
+static irqreturn_t tsc200x_irq_thread(int irq, void *_ts)
+{
+	struct tsc200x *ts = _ts;
+	unsigned long flags;
+	unsigned int pressure;
+	struct tsc200x_data tsdata;
+	int error;
+
+	/* read the coordinates */
+	error = regmap_bulk_read(ts->regmap, TSC200X_REG_X, &tsdata,
+				 TSC200X_DATA_REGS);
+	if (unlikely(error))
+		goto out;
+
+	/* validate position */
+	if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT))
+		goto out;
+
+	/* Skip reading if the pressure components are out of range */
+	if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT))
+		goto out;
+	if (unlikely(tsdata.z1 >= tsdata.z2))
+		goto out;
+
+       /*
+	* Skip point if this is a pen down with the exact same values as
+	* the value before pen-up - that implies SPI fed us stale data
+	*/
+	if (!ts->pen_down &&
+	    ts->in_x == tsdata.x && ts->in_y == tsdata.y &&
+	    ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) {
+		goto out;
+	}
+
+	/*
+	 * At this point we are happy we have a valid and useful reading.
+	 * Remember it for later comparisons. We may now begin downsampling.
+	 */
+	ts->in_x = tsdata.x;
+	ts->in_y = tsdata.y;
+	ts->in_z1 = tsdata.z1;
+	ts->in_z2 = tsdata.z2;
+
+	/* Compute touch pressure resistance using equation #1 */
+	pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1;
+	pressure = pressure * ts->x_plate_ohm / 4096;
+	if (unlikely(pressure > MAX_12BIT))
+		goto out;
+
+	spin_lock_irqsave(&ts->lock, flags);
+
+	tsc200x_update_pen_state(ts, tsdata.x, tsdata.y, pressure);
+	mod_timer(&ts->penup_timer,
+		  jiffies + msecs_to_jiffies(TSC200X_PENUP_TIME_MS));
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+
+	ts->last_valid_interrupt = jiffies;
+out:
+	return IRQ_HANDLED;
+}
+
+static void tsc200x_penup_timer(struct timer_list *t)
+{
+	struct tsc200x *ts = from_timer(ts, t, penup_timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+	tsc200x_update_pen_state(ts, 0, 0, 0);
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static void tsc200x_start_scan(struct tsc200x *ts)
+{
+	regmap_write(ts->regmap, TSC200X_REG_CFR0, TSC200X_CFR0_INITVALUE);
+	regmap_write(ts->regmap, TSC200X_REG_CFR1, TSC200X_CFR1_INITVALUE);
+	regmap_write(ts->regmap, TSC200X_REG_CFR2, TSC200X_CFR2_INITVALUE);
+	ts->tsc200x_cmd(ts->dev, TSC200X_CMD_NORMAL);
+}
+
+static void tsc200x_stop_scan(struct tsc200x *ts)
+{
+	ts->tsc200x_cmd(ts->dev, TSC200X_CMD_STOP);
+}
+
+static void tsc200x_reset(struct tsc200x *ts)
+{
+	if (ts->reset_gpio) {
+		gpiod_set_value_cansleep(ts->reset_gpio, 1);
+		usleep_range(100, 500); /* only 10us required */
+		gpiod_set_value_cansleep(ts->reset_gpio, 0);
+	}
+}
+
+/* must be called with ts->mutex held */
+static void __tsc200x_disable(struct tsc200x *ts)
+{
+	tsc200x_stop_scan(ts);
+
+	disable_irq(ts->irq);
+	del_timer_sync(&ts->penup_timer);
+
+	cancel_delayed_work_sync(&ts->esd_work);
+
+	enable_irq(ts->irq);
+}
+
+/* must be called with ts->mutex held */
+static void __tsc200x_enable(struct tsc200x *ts)
+{
+	tsc200x_start_scan(ts);
+
+	if (ts->esd_timeout && ts->reset_gpio) {
+		ts->last_valid_interrupt = jiffies;
+		schedule_delayed_work(&ts->esd_work,
+				round_jiffies_relative(
+					msecs_to_jiffies(ts->esd_timeout)));
+	}
+}
+
+static ssize_t tsc200x_selftest_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct tsc200x *ts = dev_get_drvdata(dev);
+	unsigned int temp_high;
+	unsigned int temp_high_orig;
+	unsigned int temp_high_test;
+	bool success = true;
+	int error;
+
+	mutex_lock(&ts->mutex);
+
+	/*
+	 * Test TSC200X communications via temp high register.
+	 */
+	__tsc200x_disable(ts);
+
+	error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high_orig);
+	if (error) {
+		dev_warn(dev, "selftest failed: read error %d\n", error);
+		success = false;
+		goto out;
+	}
+
+	temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
+
+	error = regmap_write(ts->regmap, TSC200X_REG_TEMP_HIGH, temp_high_test);
+	if (error) {
+		dev_warn(dev, "selftest failed: write error %d\n", error);
+		success = false;
+		goto out;
+	}
+
+	error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high);
+	if (error) {
+		dev_warn(dev, "selftest failed: read error %d after write\n",
+			 error);
+		success = false;
+		goto out;
+	}
+
+	if (temp_high != temp_high_test) {
+		dev_warn(dev, "selftest failed: %d != %d\n",
+			 temp_high, temp_high_test);
+		success = false;
+	}
+
+	/* hardware reset */
+	tsc200x_reset(ts);
+
+	if (!success)
+		goto out;
+
+	/* test that the reset really happened */
+	error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high);
+	if (error) {
+		dev_warn(dev, "selftest failed: read error %d after reset\n",
+			 error);
+		success = false;
+		goto out;
+	}
+
+	if (temp_high != temp_high_orig) {
+		dev_warn(dev, "selftest failed after reset: %d != %d\n",
+			 temp_high, temp_high_orig);
+		success = false;
+	}
+
+out:
+	__tsc200x_enable(ts);
+	mutex_unlock(&ts->mutex);
+
+	return sprintf(buf, "%d\n", success);
+}
+
+static DEVICE_ATTR(selftest, S_IRUGO, tsc200x_selftest_show, NULL);
+
+static struct attribute *tsc200x_attrs[] = {
+	&dev_attr_selftest.attr,
+	NULL
+};
+
+static umode_t tsc200x_attr_is_visible(struct kobject *kobj,
+				      struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct tsc200x *ts = dev_get_drvdata(dev);
+	umode_t mode = attr->mode;
+
+	if (attr == &dev_attr_selftest.attr) {
+		if (!ts->reset_gpio)
+			mode = 0;
+	}
+
+	return mode;
+}
+
+static const struct attribute_group tsc200x_attr_group = {
+	.is_visible	= tsc200x_attr_is_visible,
+	.attrs		= tsc200x_attrs,
+};
+
+static void tsc200x_esd_work(struct work_struct *work)
+{
+	struct tsc200x *ts = container_of(work, struct tsc200x, esd_work.work);
+	int error;
+	unsigned int r;
+
+	if (!mutex_trylock(&ts->mutex)) {
+		/*
+		 * If the mutex is taken, it means that disable or enable is in
+		 * progress. In that case just reschedule the work. If the work
+		 * is not needed, it will be canceled by disable.
+		 */
+		goto reschedule;
+	}
+
+	if (time_is_after_jiffies(ts->last_valid_interrupt +
+				  msecs_to_jiffies(ts->esd_timeout)))
+		goto out;
+
+	/* We should be able to read register without disabling interrupts. */
+	error = regmap_read(ts->regmap, TSC200X_REG_CFR0, &r);
+	if (!error &&
+	    !((r ^ TSC200X_CFR0_INITVALUE) & TSC200X_CFR0_RW_MASK)) {
+		goto out;
+	}
+
+	/*
+	 * If we could not read our known value from configuration register 0
+	 * then we should reset the controller as if from power-up and start
+	 * scanning again.
+	 */
+	dev_info(ts->dev, "TSC200X not responding - resetting\n");
+
+	disable_irq(ts->irq);
+	del_timer_sync(&ts->penup_timer);
+
+	tsc200x_update_pen_state(ts, 0, 0, 0);
+
+	tsc200x_reset(ts);
+
+	enable_irq(ts->irq);
+	tsc200x_start_scan(ts);
+
+out:
+	mutex_unlock(&ts->mutex);
+reschedule:
+	/* re-arm the watchdog */
+	schedule_delayed_work(&ts->esd_work,
+			      round_jiffies_relative(
+					msecs_to_jiffies(ts->esd_timeout)));
+}
+
+static int tsc200x_open(struct input_dev *input)
+{
+	struct tsc200x *ts = input_get_drvdata(input);
+
+	mutex_lock(&ts->mutex);
+
+	if (!ts->suspended)
+		__tsc200x_enable(ts);
+
+	ts->opened = true;
+
+	mutex_unlock(&ts->mutex);
+
+	return 0;
+}
+
+static void tsc200x_close(struct input_dev *input)
+{
+	struct tsc200x *ts = input_get_drvdata(input);
+
+	mutex_lock(&ts->mutex);
+
+	if (!ts->suspended)
+		__tsc200x_disable(ts);
+
+	ts->opened = false;
+
+	mutex_unlock(&ts->mutex);
+}
+
+int tsc200x_probe(struct device *dev, int irq, const struct input_id *tsc_id,
+		  struct regmap *regmap,
+		  int (*tsc200x_cmd)(struct device *dev, u8 cmd))
+{
+	struct tsc200x *ts;
+	struct input_dev *input_dev;
+	u32 x_plate_ohm;
+	u32 esd_timeout;
+	int error;
+
+	if (irq <= 0) {
+		dev_err(dev, "no irq\n");
+		return -ENODEV;
+	}
+
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	if (!tsc200x_cmd) {
+		dev_err(dev, "no cmd function\n");
+		return -ENODEV;
+	}
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	input_dev = devm_input_allocate_device(dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	ts->irq = irq;
+	ts->dev = dev;
+	ts->idev = input_dev;
+	ts->regmap = regmap;
+	ts->tsc200x_cmd = tsc200x_cmd;
+
+	error = device_property_read_u32(dev, "ti,x-plate-ohms", &x_plate_ohm);
+	ts->x_plate_ohm = error ? TSC200X_DEF_RESISTOR : x_plate_ohm;
+
+	error = device_property_read_u32(dev, "ti,esd-recovery-timeout-ms",
+					 &esd_timeout);
+	ts->esd_timeout = error ? 0 : esd_timeout;
+
+	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts->reset_gpio)) {
+		error = PTR_ERR(ts->reset_gpio);
+		dev_err(dev, "error acquiring reset gpio: %d\n", error);
+		return error;
+	}
+
+	ts->vio = devm_regulator_get(dev, "vio");
+	if (IS_ERR(ts->vio)) {
+		error = PTR_ERR(ts->vio);
+		dev_err(dev, "error acquiring vio regulator: %d", error);
+		return error;
+	}
+
+	mutex_init(&ts->mutex);
+
+	spin_lock_init(&ts->lock);
+	timer_setup(&ts->penup_timer, tsc200x_penup_timer, 0);
+
+	INIT_DELAYED_WORK(&ts->esd_work, tsc200x_esd_work);
+
+	snprintf(ts->phys, sizeof(ts->phys),
+		 "%s/input-ts", dev_name(dev));
+
+	if (tsc_id->product == 2004) {
+		input_dev->name = "TSC200X touchscreen";
+	} else {
+		input_dev->name = devm_kasprintf(dev, GFP_KERNEL,
+						 "TSC%04d touchscreen",
+						 tsc_id->product);
+		if (!input_dev->name)
+			return -ENOMEM;
+	}
+
+	input_dev->phys = ts->phys;
+	input_dev->id = *tsc_id;
+
+	input_dev->open = tsc200x_open;
+	input_dev->close = tsc200x_close;
+
+	input_set_drvdata(input_dev, ts);
+
+	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
+	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+
+	input_set_abs_params(input_dev, ABS_X,
+			     0, MAX_12BIT, TSC200X_DEF_X_FUZZ, 0);
+	input_set_abs_params(input_dev, ABS_Y,
+			     0, MAX_12BIT, TSC200X_DEF_Y_FUZZ, 0);
+	input_set_abs_params(input_dev, ABS_PRESSURE,
+			     0, MAX_12BIT, TSC200X_DEF_P_FUZZ, 0);
+
+	touchscreen_parse_properties(input_dev, false, &ts->prop);
+
+	/* Ensure the touchscreen is off */
+	tsc200x_stop_scan(ts);
+
+	error = devm_request_threaded_irq(dev, irq, NULL,
+					  tsc200x_irq_thread,
+					  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					  "tsc200x", ts);
+	if (error) {
+		dev_err(dev, "Failed to request irq, err: %d\n", error);
+		return error;
+	}
+
+	error = regulator_enable(ts->vio);
+	if (error)
+		return error;
+
+	dev_set_drvdata(dev, ts);
+	error = sysfs_create_group(&dev->kobj, &tsc200x_attr_group);
+	if (error) {
+		dev_err(dev,
+			"Failed to create sysfs attributes, err: %d\n", error);
+		goto disable_regulator;
+	}
+
+	error = input_register_device(ts->idev);
+	if (error) {
+		dev_err(dev,
+			"Failed to register input device, err: %d\n", error);
+		goto err_remove_sysfs;
+	}
+
+	irq_set_irq_wake(irq, 1);
+	return 0;
+
+err_remove_sysfs:
+	sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
+disable_regulator:
+	regulator_disable(ts->vio);
+	return error;
+}
+EXPORT_SYMBOL_GPL(tsc200x_probe);
+
+void tsc200x_remove(struct device *dev)
+{
+	struct tsc200x *ts = dev_get_drvdata(dev);
+
+	sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
+
+	regulator_disable(ts->vio);
+}
+EXPORT_SYMBOL_GPL(tsc200x_remove);
+
+static int __maybe_unused tsc200x_suspend(struct device *dev)
+{
+	struct tsc200x *ts = dev_get_drvdata(dev);
+
+	mutex_lock(&ts->mutex);
+
+	if (!ts->suspended && ts->opened)
+		__tsc200x_disable(ts);
+
+	ts->suspended = true;
+
+	mutex_unlock(&ts->mutex);
+
+	return 0;
+}
+
+static int __maybe_unused tsc200x_resume(struct device *dev)
+{
+	struct tsc200x *ts = dev_get_drvdata(dev);
+
+	mutex_lock(&ts->mutex);
+
+	if (ts->suspended && ts->opened)
+		__tsc200x_enable(ts);
+
+	ts->suspended = false;
+
+	mutex_unlock(&ts->mutex);
+
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(tsc200x_pm_ops, tsc200x_suspend, tsc200x_resume);
+EXPORT_SYMBOL_GPL(tsc200x_pm_ops);
+
+MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
+MODULE_DESCRIPTION("TSC200x Touchscreen Driver Core");
+MODULE_LICENSE("GPL");