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- /*
- * 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, const struct input_id *tsc_id,
- 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));
- 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->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");
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