--- /dev/null
+/*
+ * 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>
+ *
+ * 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.
+ */
+
+#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/spi/tsc2005.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_rw = 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;
+
+ 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;
+ void (*set_reset)(bool enable);
+ 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) {
+ input_report_abs(ts->idev, ABS_X, x);
+ input_report_abs(ts->idev, ABS_Y, y);
+ 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(unsigned long data)
+{
+ struct tsc200x *ts = (struct tsc200x *)data;
+ 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_set_reset(struct tsc200x *ts, bool enable)
+{
+ if (ts->reset_gpio)
+ gpiod_set_value_cansleep(ts->reset_gpio, enable);
+ else if (ts->set_reset)
+ ts->set_reset(enable);
+}
+
+/* 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->set_reset || 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_set_reset(ts, false);
+ usleep_range(100, 500); /* only 10us required */
+ tsc200x_set_reset(ts, true);
+
+ 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 = container_of(kobj, struct device, kobj);
+ struct tsc200x *ts = dev_get_drvdata(dev);
+ umode_t mode = attr->mode;
+
+ if (attr == &dev_attr_selftest.attr) {
+ if (!ts->set_reset && !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_set_reset(ts, false);
+ usleep_range(100, 500); /* only 10us required */
+ tsc200x_set_reset(ts, true);
+
+ 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, __u16 bustype,
+ struct regmap *regmap,
+ int (*tsc200x_cmd)(struct device *dev, u8 cmd))
+{
+ const struct tsc2005_platform_data *pdata = dev_get_platdata(dev);
+ struct device_node *np = dev->of_node;
+
+ struct tsc200x *ts;
+ struct input_dev *input_dev;
+ unsigned int max_x = MAX_12BIT;
+ unsigned int max_y = MAX_12BIT;
+ unsigned int max_p = MAX_12BIT;
+ unsigned int fudge_x = TSC200X_DEF_X_FUZZ;
+ unsigned int fudge_y = TSC200X_DEF_Y_FUZZ;
+ unsigned int fudge_p = TSC200X_DEF_P_FUZZ;
+ unsigned int x_plate_ohm = TSC200X_DEF_RESISTOR;
+ unsigned int esd_timeout;
+ int error;
+
+ if (!np && !pdata) {
+ dev_err(dev, "no platform data\n");
+ return -ENODEV;
+ }
+
+ 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;
+ }
+
+ if (pdata) {
+ fudge_x = pdata->ts_x_fudge;
+ fudge_y = pdata->ts_y_fudge;
+ fudge_p = pdata->ts_pressure_fudge;
+ max_x = pdata->ts_x_max;
+ max_y = pdata->ts_y_max;
+ max_p = pdata->ts_pressure_max;
+ x_plate_ohm = pdata->ts_x_plate_ohm;
+ esd_timeout = pdata->esd_timeout_ms;
+ } else {
+ x_plate_ohm = TSC200X_DEF_RESISTOR;
+ of_property_read_u32(np, "ti,x-plate-ohms", &x_plate_ohm);
+ esd_timeout = 0;
+ of_property_read_u32(np, "ti,esd-recovery-timeout-ms",
+ &esd_timeout);
+ }
+
+ 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;
+ ts->x_plate_ohm = x_plate_ohm;
+ ts->esd_timeout = 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_optional(dev, "vio");
+ if (IS_ERR(ts->vio)) {
+ error = PTR_ERR(ts->vio);
+ dev_err(dev, "vio regulator missing (%d)", error);
+ return error;
+ }
+
+ if (!ts->reset_gpio && pdata)
+ ts->set_reset = pdata->set_reset;
+
+ mutex_init(&ts->mutex);
+
+ spin_lock_init(&ts->lock);
+ setup_timer(&ts->penup_timer, tsc200x_penup_timer, (unsigned long)ts);
+
+ INIT_DELAYED_WORK(&ts->esd_work, tsc200x_esd_work);
+
+ snprintf(ts->phys, sizeof(ts->phys),
+ "%s/input-ts", dev_name(dev));
+
+ input_dev->name = "TSC200X touchscreen";
+ input_dev->phys = ts->phys;
+ input_dev->id.bustype = bustype;
+ input_dev->dev.parent = dev;
+ input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
+ input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+ input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
+ input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
+ input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
+
+ if (np)
+ touchscreen_parse_properties(input_dev, false);
+
+ input_dev->open = tsc200x_open;
+ input_dev->close = tsc200x_close;
+
+ input_set_drvdata(input_dev, ts);
+
+ /* 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;
+ }
+
+ /* enable regulator for DT */
+ if (ts->vio) {
+ 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:
+ if (ts->vio)
+ regulator_disable(ts->vio);
+ return error;
+}
+EXPORT_SYMBOL_GPL(tsc200x_probe);
+
+int tsc200x_remove(struct device *dev)
+{
+ struct tsc200x *ts = dev_get_drvdata(dev);
+
+ sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
+
+ if (ts->vio)
+ regulator_disable(ts->vio);
+
+ return 0;
+}
+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");
Code Review / kvmfornfv.git / blobdiff