diff options
Diffstat (limited to 'drivers/input/touchscreen/tsc200x-core.c')
| -rw-r--r-- | drivers/input/touchscreen/tsc200x-core.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/tsc200x-core.c b/drivers/input/touchscreen/tsc200x-core.c new file mode 100644 index 000000000000..15240c1ee850 --- /dev/null +++ b/drivers/input/touchscreen/tsc200x-core.c @@ -0,0 +1,665 @@ +/* + * 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"); |