| /* |
| * 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/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; |
| |
| 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) { |
| 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(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 = 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->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, NULL); |
| |
| /* 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); |
| |
| int tsc200x_remove(struct device *dev) |
| { |
| struct tsc200x *ts = dev_get_drvdata(dev); |
| |
| sysfs_remove_group(&dev->kobj, &tsc200x_attr_group); |
| |
| 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"); |