/* * 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 * based on TSC2301 driver by Klaus K. Pedersen * * 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 #include #include #include #include #include #include #include #include #include #include #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; 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_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); 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->open = tsc200x_open; input_dev->close = tsc200x_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, 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 "); MODULE_DESCRIPTION("TSC200x Touchscreen Driver Core"); MODULE_LICENSE("GPL");