2 * TSC2005 touchscreen driver
4 * Copyright (C) 2006-2010 Nokia Corporation
6 * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
7 * based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/input.h>
28 #include <linux/input/touchscreen.h>
29 #include <linux/interrupt.h>
30 #include <linux/delay.h>
33 #include <linux/spi/spi.h>
34 #include <linux/spi/tsc2005.h>
35 #include <linux/regulator/consumer.h>
36 #include <linux/regmap.h>
37 #include <linux/gpio/consumer.h>
40 * The touchscreen interface operates as follows:
42 * 1) Pen is pressed against the touchscreen.
43 * 2) TSC2005 performs AD conversion.
44 * 3) After the conversion is done TSC2005 drives DAV line down.
45 * 4) GPIO IRQ is received and tsc2005_irq_thread() is scheduled.
46 * 5) tsc2005_irq_thread() queues up an spi transfer to fetch the x, y, z1, z2
48 * 6) tsc2005_irq_thread() reports coordinates to input layer and sets up
49 * tsc2005_penup_timer() to be called after TSC2005_PENUP_TIME_MS (40ms).
50 * 7) When the penup timer expires, there have not been touch or DAV interrupts
51 * during the last 40ms which means the pen has been lifted.
53 * ESD recovery via a hardware reset is done if the TSC2005 doesn't respond
54 * after a configurable period (in ms) of activity. If esd_timeout is 0, the
55 * watchdog is disabled.
59 #define TSC2005_CMD 0x80
60 #define TSC2005_CMD_NORMAL 0x00
61 #define TSC2005_CMD_STOP 0x01
62 #define TSC2005_CMD_12BIT 0x04
65 #define TSC2005_REG_READ 0x01 /* R/W access */
66 #define TSC2005_REG_PND0 0x02 /* Power Not Down Control */
67 #define TSC2005_REG_X (0x0 << 3)
68 #define TSC2005_REG_Y (0x1 << 3)
69 #define TSC2005_REG_Z1 (0x2 << 3)
70 #define TSC2005_REG_Z2 (0x3 << 3)
71 #define TSC2005_REG_AUX (0x4 << 3)
72 #define TSC2005_REG_TEMP1 (0x5 << 3)
73 #define TSC2005_REG_TEMP2 (0x6 << 3)
74 #define TSC2005_REG_STATUS (0x7 << 3)
75 #define TSC2005_REG_AUX_HIGH (0x8 << 3)
76 #define TSC2005_REG_AUX_LOW (0x9 << 3)
77 #define TSC2005_REG_TEMP_HIGH (0xA << 3)
78 #define TSC2005_REG_TEMP_LOW (0xB << 3)
79 #define TSC2005_REG_CFR0 (0xC << 3)
80 #define TSC2005_REG_CFR1 (0xD << 3)
81 #define TSC2005_REG_CFR2 (0xE << 3)
82 #define TSC2005_REG_CONV_FUNC (0xF << 3)
84 /* configuration register 0 */
85 #define TSC2005_CFR0_PRECHARGE_276US 0x0040
86 #define TSC2005_CFR0_STABTIME_1MS 0x0300
87 #define TSC2005_CFR0_CLOCK_1MHZ 0x1000
88 #define TSC2005_CFR0_RESOLUTION12 0x2000
89 #define TSC2005_CFR0_PENMODE 0x8000
90 #define TSC2005_CFR0_INITVALUE (TSC2005_CFR0_STABTIME_1MS | \
91 TSC2005_CFR0_CLOCK_1MHZ | \
92 TSC2005_CFR0_RESOLUTION12 | \
93 TSC2005_CFR0_PRECHARGE_276US | \
96 /* bits common to both read and write of configuration register 0 */
97 #define TSC2005_CFR0_RW_MASK 0x3fff
99 /* configuration register 1 */
100 #define TSC2005_CFR1_BATCHDELAY_4MS 0x0003
101 #define TSC2005_CFR1_INITVALUE TSC2005_CFR1_BATCHDELAY_4MS
103 /* configuration register 2 */
104 #define TSC2005_CFR2_MAVE_Z 0x0004
105 #define TSC2005_CFR2_MAVE_Y 0x0008
106 #define TSC2005_CFR2_MAVE_X 0x0010
107 #define TSC2005_CFR2_AVG_7 0x0800
108 #define TSC2005_CFR2_MEDIUM_15 0x3000
109 #define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_MAVE_X | \
110 TSC2005_CFR2_MAVE_Y | \
111 TSC2005_CFR2_MAVE_Z | \
112 TSC2005_CFR2_MEDIUM_15 | \
115 #define MAX_12BIT 0xfff
116 #define TSC2005_DEF_X_FUZZ 4
117 #define TSC2005_DEF_Y_FUZZ 8
118 #define TSC2005_DEF_P_FUZZ 2
119 #define TSC2005_DEF_RESISTOR 280
121 #define TSC2005_SPI_MAX_SPEED_HZ 10000000
122 #define TSC2005_PENUP_TIME_MS 40
124 static const struct regmap_range tsc2005_writable_ranges[] = {
125 regmap_reg_range(TSC2005_REG_AUX_HIGH, TSC2005_REG_CFR2),
128 static const struct regmap_access_table tsc2005_writable_table = {
129 .yes_ranges = tsc2005_writable_ranges,
130 .n_yes_ranges = ARRAY_SIZE(tsc2005_writable_ranges),
133 static struct regmap_config tsc2005_regmap_config = {
137 .max_register = 0x78,
138 .read_flag_mask = TSC2005_REG_READ,
139 .write_flag_mask = TSC2005_REG_PND0,
140 .wr_table = &tsc2005_writable_table,
141 .use_single_rw = true,
144 struct tsc2005_data {
150 #define TSC2005_DATA_REGS 4
153 struct spi_device *spi;
154 struct regmap *regmap;
156 struct input_dev *idev;
161 /* raw copy of previous x,y,z */
168 struct timer_list penup_timer;
170 unsigned int esd_timeout;
171 struct delayed_work esd_work;
172 unsigned long last_valid_interrupt;
174 unsigned int x_plate_ohm;
181 struct regulator *vio;
183 struct gpio_desc *reset_gpio;
184 void (*set_reset)(bool enable);
187 static int tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
189 u8 tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
190 struct spi_transfer xfer = {
195 struct spi_message msg;
198 spi_message_init(&msg);
199 spi_message_add_tail(&xfer, &msg);
201 error = spi_sync(ts->spi, &msg);
203 dev_err(&ts->spi->dev, "%s: failed, command: %x, error: %d\n",
204 __func__, cmd, error);
211 static void tsc2005_update_pen_state(struct tsc2005 *ts,
212 int x, int y, int pressure)
215 input_report_abs(ts->idev, ABS_X, x);
216 input_report_abs(ts->idev, ABS_Y, y);
217 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
219 input_report_key(ts->idev, BTN_TOUCH, !!pressure);
223 input_report_abs(ts->idev, ABS_PRESSURE, 0);
225 input_report_key(ts->idev, BTN_TOUCH, 0);
226 ts->pen_down = false;
229 input_sync(ts->idev);
230 dev_dbg(&ts->spi->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
234 static irqreturn_t tsc2005_irq_thread(int irq, void *_ts)
236 struct tsc2005 *ts = _ts;
238 unsigned int pressure;
239 struct tsc2005_data tsdata;
242 /* read the coordinates */
243 error = regmap_bulk_read(ts->regmap, TSC2005_REG_X, &tsdata,
248 /* validate position */
249 if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT))
252 /* Skip reading if the pressure components are out of range */
253 if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT))
255 if (unlikely(tsdata.z1 >= tsdata.z2))
259 * Skip point if this is a pen down with the exact same values as
260 * the value before pen-up - that implies SPI fed us stale data
263 ts->in_x == tsdata.x && ts->in_y == tsdata.y &&
264 ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) {
269 * At this point we are happy we have a valid and useful reading.
270 * Remember it for later comparisons. We may now begin downsampling.
274 ts->in_z1 = tsdata.z1;
275 ts->in_z2 = tsdata.z2;
277 /* Compute touch pressure resistance using equation #1 */
278 pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1;
279 pressure = pressure * ts->x_plate_ohm / 4096;
280 if (unlikely(pressure > MAX_12BIT))
283 spin_lock_irqsave(&ts->lock, flags);
285 tsc2005_update_pen_state(ts, tsdata.x, tsdata.y, pressure);
286 mod_timer(&ts->penup_timer,
287 jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS));
289 spin_unlock_irqrestore(&ts->lock, flags);
291 ts->last_valid_interrupt = jiffies;
296 static void tsc2005_penup_timer(unsigned long data)
298 struct tsc2005 *ts = (struct tsc2005 *)data;
301 spin_lock_irqsave(&ts->lock, flags);
302 tsc2005_update_pen_state(ts, 0, 0, 0);
303 spin_unlock_irqrestore(&ts->lock, flags);
306 static void tsc2005_start_scan(struct tsc2005 *ts)
308 regmap_write(ts->regmap, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE);
309 regmap_write(ts->regmap, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE);
310 regmap_write(ts->regmap, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE);
311 tsc2005_cmd(ts, TSC2005_CMD_NORMAL);
314 static void tsc2005_stop_scan(struct tsc2005 *ts)
316 tsc2005_cmd(ts, TSC2005_CMD_STOP);
319 static void tsc2005_set_reset(struct tsc2005 *ts, bool enable)
322 gpiod_set_value_cansleep(ts->reset_gpio, enable);
323 else if (ts->set_reset)
324 ts->set_reset(enable);
327 /* must be called with ts->mutex held */
328 static void __tsc2005_disable(struct tsc2005 *ts)
330 tsc2005_stop_scan(ts);
332 disable_irq(ts->spi->irq);
333 del_timer_sync(&ts->penup_timer);
335 cancel_delayed_work_sync(&ts->esd_work);
337 enable_irq(ts->spi->irq);
340 /* must be called with ts->mutex held */
341 static void __tsc2005_enable(struct tsc2005 *ts)
343 tsc2005_start_scan(ts);
345 if (ts->esd_timeout && (ts->set_reset || ts->reset_gpio)) {
346 ts->last_valid_interrupt = jiffies;
347 schedule_delayed_work(&ts->esd_work,
348 round_jiffies_relative(
349 msecs_to_jiffies(ts->esd_timeout)));
354 static ssize_t tsc2005_selftest_show(struct device *dev,
355 struct device_attribute *attr,
358 struct tsc2005 *ts = dev_get_drvdata(dev);
359 unsigned int temp_high;
360 unsigned int temp_high_orig;
361 unsigned int temp_high_test;
365 mutex_lock(&ts->mutex);
368 * Test TSC2005 communications via temp high register.
370 __tsc2005_disable(ts);
372 error = regmap_read(ts->regmap, TSC2005_REG_TEMP_HIGH, &temp_high_orig);
374 dev_warn(dev, "selftest failed: read error %d\n", error);
379 temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
381 error = regmap_write(ts->regmap, TSC2005_REG_TEMP_HIGH, temp_high_test);
383 dev_warn(dev, "selftest failed: write error %d\n", error);
388 error = regmap_read(ts->regmap, TSC2005_REG_TEMP_HIGH, &temp_high);
390 dev_warn(dev, "selftest failed: read error %d after write\n",
396 if (temp_high != temp_high_test) {
397 dev_warn(dev, "selftest failed: %d != %d\n",
398 temp_high, temp_high_test);
403 tsc2005_set_reset(ts, false);
404 usleep_range(100, 500); /* only 10us required */
405 tsc2005_set_reset(ts, true);
410 /* test that the reset really happened */
411 error = regmap_read(ts->regmap, TSC2005_REG_TEMP_HIGH, &temp_high);
413 dev_warn(dev, "selftest failed: read error %d after reset\n",
419 if (temp_high != temp_high_orig) {
420 dev_warn(dev, "selftest failed after reset: %d != %d\n",
421 temp_high, temp_high_orig);
426 __tsc2005_enable(ts);
427 mutex_unlock(&ts->mutex);
429 return sprintf(buf, "%d\n", success);
432 static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL);
434 static struct attribute *tsc2005_attrs[] = {
435 &dev_attr_selftest.attr,
439 static umode_t tsc2005_attr_is_visible(struct kobject *kobj,
440 struct attribute *attr, int n)
442 struct device *dev = container_of(kobj, struct device, kobj);
443 struct tsc2005 *ts = dev_get_drvdata(dev);
444 umode_t mode = attr->mode;
446 if (attr == &dev_attr_selftest.attr) {
447 if (!ts->set_reset && !ts->reset_gpio)
454 static const struct attribute_group tsc2005_attr_group = {
455 .is_visible = tsc2005_attr_is_visible,
456 .attrs = tsc2005_attrs,
459 static void tsc2005_esd_work(struct work_struct *work)
461 struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work.work);
465 if (!mutex_trylock(&ts->mutex)) {
467 * If the mutex is taken, it means that disable or enable is in
468 * progress. In that case just reschedule the work. If the work
469 * is not needed, it will be canceled by disable.
474 if (time_is_after_jiffies(ts->last_valid_interrupt +
475 msecs_to_jiffies(ts->esd_timeout)))
478 /* We should be able to read register without disabling interrupts. */
479 error = regmap_read(ts->regmap, TSC2005_REG_CFR0, &r);
481 !((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK)) {
486 * If we could not read our known value from configuration register 0
487 * then we should reset the controller as if from power-up and start
490 dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n");
492 disable_irq(ts->spi->irq);
493 del_timer_sync(&ts->penup_timer);
495 tsc2005_update_pen_state(ts, 0, 0, 0);
497 tsc2005_set_reset(ts, false);
498 usleep_range(100, 500); /* only 10us required */
499 tsc2005_set_reset(ts, true);
501 enable_irq(ts->spi->irq);
502 tsc2005_start_scan(ts);
505 mutex_unlock(&ts->mutex);
507 /* re-arm the watchdog */
508 schedule_delayed_work(&ts->esd_work,
509 round_jiffies_relative(
510 msecs_to_jiffies(ts->esd_timeout)));
513 static int tsc2005_open(struct input_dev *input)
515 struct tsc2005 *ts = input_get_drvdata(input);
517 mutex_lock(&ts->mutex);
520 __tsc2005_enable(ts);
524 mutex_unlock(&ts->mutex);
529 static void tsc2005_close(struct input_dev *input)
531 struct tsc2005 *ts = input_get_drvdata(input);
533 mutex_lock(&ts->mutex);
536 __tsc2005_disable(ts);
540 mutex_unlock(&ts->mutex);
543 static int tsc2005_probe(struct spi_device *spi)
545 const struct tsc2005_platform_data *pdata = dev_get_platdata(&spi->dev);
546 struct device_node *np = spi->dev.of_node;
549 struct input_dev *input_dev;
550 unsigned int max_x = MAX_12BIT;
551 unsigned int max_y = MAX_12BIT;
552 unsigned int max_p = MAX_12BIT;
553 unsigned int fudge_x = TSC2005_DEF_X_FUZZ;
554 unsigned int fudge_y = TSC2005_DEF_Y_FUZZ;
555 unsigned int fudge_p = TSC2005_DEF_P_FUZZ;
556 unsigned int x_plate_ohm = TSC2005_DEF_RESISTOR;
557 unsigned int esd_timeout;
561 dev_err(&spi->dev, "no platform data\n");
566 dev_err(&spi->dev, "no irq\n");
571 fudge_x = pdata->ts_x_fudge;
572 fudge_y = pdata->ts_y_fudge;
573 fudge_p = pdata->ts_pressure_fudge;
574 max_x = pdata->ts_x_max;
575 max_y = pdata->ts_y_max;
576 max_p = pdata->ts_pressure_max;
577 x_plate_ohm = pdata->ts_x_plate_ohm;
578 esd_timeout = pdata->esd_timeout_ms;
580 x_plate_ohm = TSC2005_DEF_RESISTOR;
581 of_property_read_u32(np, "ti,x-plate-ohms", &x_plate_ohm);
583 of_property_read_u32(np, "ti,esd-recovery-timeout-ms",
587 spi->mode = SPI_MODE_0;
588 spi->bits_per_word = 8;
589 if (!spi->max_speed_hz)
590 spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ;
592 error = spi_setup(spi);
596 ts = devm_kzalloc(&spi->dev, sizeof(*ts), GFP_KERNEL);
600 input_dev = devm_input_allocate_device(&spi->dev);
605 ts->idev = input_dev;
607 ts->regmap = devm_regmap_init_spi(spi, &tsc2005_regmap_config);
608 if (IS_ERR(ts->regmap))
609 return PTR_ERR(ts->regmap);
611 ts->x_plate_ohm = x_plate_ohm;
612 ts->esd_timeout = esd_timeout;
614 ts->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
616 if (IS_ERR(ts->reset_gpio)) {
617 error = PTR_ERR(ts->reset_gpio);
618 dev_err(&spi->dev, "error acquiring reset gpio: %d\n", error);
622 ts->vio = devm_regulator_get_optional(&spi->dev, "vio");
623 if (IS_ERR(ts->vio)) {
624 error = PTR_ERR(ts->vio);
625 dev_err(&spi->dev, "vio regulator missing (%d)", error);
629 if (!ts->reset_gpio && pdata)
630 ts->set_reset = pdata->set_reset;
632 mutex_init(&ts->mutex);
634 spin_lock_init(&ts->lock);
635 setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts);
637 INIT_DELAYED_WORK(&ts->esd_work, tsc2005_esd_work);
639 snprintf(ts->phys, sizeof(ts->phys),
640 "%s/input-ts", dev_name(&spi->dev));
642 input_dev->name = "TSC2005 touchscreen";
643 input_dev->phys = ts->phys;
644 input_dev->id.bustype = BUS_SPI;
645 input_dev->dev.parent = &spi->dev;
646 input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
647 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
649 input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
650 input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
651 input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
654 touchscreen_parse_properties(input_dev, false);
656 input_dev->open = tsc2005_open;
657 input_dev->close = tsc2005_close;
659 input_set_drvdata(input_dev, ts);
661 /* Ensure the touchscreen is off */
662 tsc2005_stop_scan(ts);
664 error = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
666 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
669 dev_err(&spi->dev, "Failed to request irq, err: %d\n", error);
673 /* enable regulator for DT */
675 error = regulator_enable(ts->vio);
680 dev_set_drvdata(&spi->dev, ts);
681 error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group);
684 "Failed to create sysfs attributes, err: %d\n", error);
685 goto disable_regulator;
688 error = input_register_device(ts->idev);
691 "Failed to register input device, err: %d\n", error);
692 goto err_remove_sysfs;
695 irq_set_irq_wake(spi->irq, 1);
699 sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
702 regulator_disable(ts->vio);
706 static int tsc2005_remove(struct spi_device *spi)
708 struct tsc2005 *ts = dev_get_drvdata(&spi->dev);
710 sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
713 regulator_disable(ts->vio);
718 static int __maybe_unused tsc2005_suspend(struct device *dev)
720 struct tsc2005 *ts = dev_get_drvdata(dev);
722 mutex_lock(&ts->mutex);
724 if (!ts->suspended && ts->opened)
725 __tsc2005_disable(ts);
727 ts->suspended = true;
729 mutex_unlock(&ts->mutex);
734 static int __maybe_unused tsc2005_resume(struct device *dev)
736 struct tsc2005 *ts = dev_get_drvdata(dev);
738 mutex_lock(&ts->mutex);
740 if (ts->suspended && ts->opened)
741 __tsc2005_enable(ts);
743 ts->suspended = false;
745 mutex_unlock(&ts->mutex);
750 static SIMPLE_DEV_PM_OPS(tsc2005_pm_ops, tsc2005_suspend, tsc2005_resume);
752 static struct spi_driver tsc2005_driver = {
755 .owner = THIS_MODULE,
756 .pm = &tsc2005_pm_ops,
758 .probe = tsc2005_probe,
759 .remove = tsc2005_remove,
762 module_spi_driver(tsc2005_driver);
764 MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
765 MODULE_DESCRIPTION("TSC2005 Touchscreen Driver");
766 MODULE_LICENSE("GPL");
767 MODULE_ALIAS("spi:tsc2005");