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/interrupt.h>
29 #include <linux/delay.h>
31 #include <linux/spi/spi.h>
32 #include <linux/spi/tsc2005.h>
35 * The touchscreen interface operates as follows:
37 * 1) Pen is pressed against the touchscreen.
38 * 2) TSC2005 performs AD conversion.
39 * 3) After the conversion is done TSC2005 drives DAV line down.
40 * 4) GPIO IRQ is received and tsc2005_irq_thread() is scheduled.
41 * 5) tsc2005_irq_thread() queues up an spi transfer to fetch the x, y, z1, z2
43 * 6) tsc2005_irq_thread() reports coordinates to input layer and sets up
44 * tsc2005_penup_timer() to be called after TSC2005_PENUP_TIME_MS (40ms).
45 * 7) When the penup timer expires, there have not been touch or DAV interrupts
46 * during the last 40ms which means the pen has been lifted.
48 * ESD recovery via a hardware reset is done if the TSC2005 doesn't respond
49 * after a configurable period (in ms) of activity. If esd_timeout is 0, the
50 * watchdog is disabled.
54 #define TSC2005_CMD 0x80
55 #define TSC2005_CMD_NORMAL 0x00
56 #define TSC2005_CMD_STOP 0x01
57 #define TSC2005_CMD_12BIT 0x04
60 #define TSC2005_REG_READ 0x0001
61 #define TSC2005_REG_PND0 0x0002
62 #define TSC2005_REG_X 0x0000
63 #define TSC2005_REG_Y 0x0008
64 #define TSC2005_REG_Z1 0x0010
65 #define TSC2005_REG_Z2 0x0018
66 #define TSC2005_REG_TEMP_HIGH 0x0050
67 #define TSC2005_REG_CFR0 0x0060
68 #define TSC2005_REG_CFR1 0x0068
69 #define TSC2005_REG_CFR2 0x0070
71 /* configuration register 0 */
72 #define TSC2005_CFR0_PRECHARGE_276US 0x0040
73 #define TSC2005_CFR0_STABTIME_1MS 0x0300
74 #define TSC2005_CFR0_CLOCK_1MHZ 0x1000
75 #define TSC2005_CFR0_RESOLUTION12 0x2000
76 #define TSC2005_CFR0_PENMODE 0x8000
77 #define TSC2005_CFR0_INITVALUE (TSC2005_CFR0_STABTIME_1MS | \
78 TSC2005_CFR0_CLOCK_1MHZ | \
79 TSC2005_CFR0_RESOLUTION12 | \
80 TSC2005_CFR0_PRECHARGE_276US | \
83 /* bits common to both read and write of configuration register 0 */
84 #define TSC2005_CFR0_RW_MASK 0x3fff
86 /* configuration register 1 */
87 #define TSC2005_CFR1_BATCHDELAY_4MS 0x0003
88 #define TSC2005_CFR1_INITVALUE TSC2005_CFR1_BATCHDELAY_4MS
90 /* configuration register 2 */
91 #define TSC2005_CFR2_MAVE_Z 0x0004
92 #define TSC2005_CFR2_MAVE_Y 0x0008
93 #define TSC2005_CFR2_MAVE_X 0x0010
94 #define TSC2005_CFR2_AVG_7 0x0800
95 #define TSC2005_CFR2_MEDIUM_15 0x3000
96 #define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_MAVE_X | \
97 TSC2005_CFR2_MAVE_Y | \
98 TSC2005_CFR2_MAVE_Z | \
99 TSC2005_CFR2_MEDIUM_15 | \
102 #define MAX_12BIT 0xfff
103 #define TSC2005_SPI_MAX_SPEED_HZ 10000000
104 #define TSC2005_PENUP_TIME_MS 40
106 struct tsc2005_spi_rd {
107 struct spi_transfer spi_xfer;
113 struct spi_device *spi;
115 struct spi_message spi_read_msg;
116 struct tsc2005_spi_rd spi_x;
117 struct tsc2005_spi_rd spi_y;
118 struct tsc2005_spi_rd spi_z1;
119 struct tsc2005_spi_rd spi_z2;
121 struct input_dev *idev;
126 /* raw copy of previous x,y,z */
132 struct timer_list penup_timer;
133 struct work_struct penup_work;
135 unsigned int esd_timeout;
136 struct timer_list esd_timer;
137 struct work_struct esd_work;
139 unsigned int x_plate_ohm;
142 unsigned int disable_depth;
143 unsigned int pen_down;
145 void (*set_reset)(bool enable);
148 static void tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
151 struct spi_message msg;
152 struct spi_transfer xfer = { 0 };
154 tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
159 xfer.bits_per_word = 8;
161 spi_message_init(&msg);
162 spi_message_add_tail(&xfer, &msg);
163 spi_sync(ts->spi, &msg);
166 static void tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value)
169 struct spi_message msg;
170 struct spi_transfer xfer = { 0 };
172 tx = (reg | TSC2005_REG_PND0) << 16;
178 xfer.bits_per_word = 24;
180 spi_message_init(&msg);
181 spi_message_add_tail(&xfer, &msg);
182 spi_sync(ts->spi, &msg);
185 static void tsc2005_setup_read(struct tsc2005_spi_rd *rd, u8 reg, bool last)
187 rd->spi_tx = (reg | TSC2005_REG_READ) << 16;
188 rd->spi_xfer.tx_buf = &rd->spi_tx;
189 rd->spi_xfer.rx_buf = &rd->spi_rx;
190 rd->spi_xfer.len = 4;
191 rd->spi_xfer.bits_per_word = 24;
192 rd->spi_xfer.cs_change = !last;
195 static void tsc2005_read(struct tsc2005 *ts, u8 reg, u16 *value)
197 struct spi_message msg;
198 struct tsc2005_spi_rd spi_rd = { { 0 }, 0, 0 };
200 tsc2005_setup_read(&spi_rd, reg, 1);
202 spi_message_init(&msg);
203 spi_message_add_tail(&spi_rd.spi_xfer, &msg);
204 spi_sync(ts->spi, &msg);
205 *value = spi_rd.spi_rx;
208 static void tsc2005_update_pen_state(struct tsc2005 *ts,
209 int x, int y, int pressure)
212 input_report_abs(ts->idev, ABS_X, x);
213 input_report_abs(ts->idev, ABS_Y, y);
214 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
216 input_report_key(ts->idev, BTN_TOUCH, !!pressure);
220 input_report_abs(ts->idev, ABS_PRESSURE, 0);
222 input_report_key(ts->idev, BTN_TOUCH, 0);
226 input_sync(ts->idev);
227 dev_dbg(&ts->spi->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
231 static irqreturn_t tsc2005_irq_handler(int irq, void *dev_id)
233 struct tsc2005 *ts = dev_id;
235 /* update the penup timer only if it's pending */
236 mod_timer_pending(&ts->penup_timer,
237 jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS));
239 return IRQ_WAKE_THREAD;
242 static irqreturn_t tsc2005_irq_thread(int irq, void *_ts)
244 struct tsc2005 *ts = _ts;
245 unsigned int pressure;
251 mutex_lock(&ts->mutex);
253 if (unlikely(ts->disable_depth))
256 /* read the coordinates */
257 spi_sync(ts->spi, &ts->spi_read_msg);
258 x = ts->spi_x.spi_rx;
259 y = ts->spi_y.spi_rx;
260 z1 = ts->spi_z1.spi_rx;
261 z2 = ts->spi_z2.spi_rx;
263 /* validate position */
264 if (unlikely(x > MAX_12BIT || y > MAX_12BIT))
267 /* skip coords if the pressure components are out of range */
268 if (unlikely(z1 == 0 || z2 > MAX_12BIT || z1 >= z2))
271 /* skip point if this is a pen down with the exact same values as
272 * the value before pen-up - that implies SPI fed us stale data
281 /* At this point we are happy we have a valid and useful reading.
282 * Remember it for later comparisons. We may now begin downsampling
289 /* compute touch pressure resistance using equation #1 */
290 pressure = x * (z2 - z1) / z1;
291 pressure = pressure * ts->x_plate_ohm / 4096;
292 if (unlikely(pressure > MAX_12BIT))
295 tsc2005_update_pen_state(ts, x, y, pressure);
297 /* set the penup timer */
298 mod_timer(&ts->penup_timer,
299 jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS));
301 if (!ts->esd_timeout)
304 /* update the watchdog timer */
305 mod_timer(&ts->esd_timer,
306 round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout)));
309 mutex_unlock(&ts->mutex);
313 static void tsc2005_penup_timer(unsigned long data)
315 struct tsc2005 *ts = (struct tsc2005 *)data;
317 schedule_work(&ts->penup_work);
320 static void tsc2005_penup_work(struct work_struct *work)
322 struct tsc2005 *ts = container_of(work, struct tsc2005, penup_work);
324 mutex_lock(&ts->mutex);
325 tsc2005_update_pen_state(ts, 0, 0, 0);
326 mutex_unlock(&ts->mutex);
329 static void tsc2005_start_scan(struct tsc2005 *ts)
331 tsc2005_write(ts, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE);
332 tsc2005_write(ts, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE);
333 tsc2005_write(ts, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE);
334 tsc2005_cmd(ts, TSC2005_CMD_NORMAL);
337 static void tsc2005_stop_scan(struct tsc2005 *ts)
339 tsc2005_cmd(ts, TSC2005_CMD_STOP);
342 /* must be called with mutex held */
343 static void tsc2005_disable(struct tsc2005 *ts)
345 if (ts->disable_depth++ != 0)
347 disable_irq(ts->spi->irq);
349 del_timer_sync(&ts->esd_timer);
350 del_timer_sync(&ts->penup_timer);
351 tsc2005_stop_scan(ts);
354 /* must be called with mutex held */
355 static void tsc2005_enable(struct tsc2005 *ts)
357 if (--ts->disable_depth != 0)
359 tsc2005_start_scan(ts);
360 enable_irq(ts->spi->irq);
361 if (!ts->esd_timeout)
363 mod_timer(&ts->esd_timer,
364 round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout)));
367 static ssize_t tsc2005_disable_show(struct device *dev,
368 struct device_attribute *attr, char *buf)
370 struct spi_device *spi = to_spi_device(dev);
371 struct tsc2005 *ts = spi_get_drvdata(spi);
373 return sprintf(buf, "%u\n", ts->disabled);
376 static ssize_t tsc2005_disable_store(struct device *dev,
377 struct device_attribute *attr,
378 const char *buf, size_t count)
380 struct spi_device *spi = to_spi_device(dev);
381 struct tsc2005 *ts = spi_get_drvdata(spi);
385 if (strict_strtoul(buf, 10, &res) < 0)
389 mutex_lock(&ts->mutex);
390 if (i == ts->disabled)
398 mutex_unlock(&ts->mutex);
401 static DEVICE_ATTR(disable, 0664, tsc2005_disable_show, tsc2005_disable_store);
403 static ssize_t tsc2005_selftest_show(struct device *dev,
404 struct device_attribute *attr,
407 struct spi_device *spi = to_spi_device(dev);
408 struct tsc2005 *ts = spi_get_drvdata(spi);
414 mutex_lock(&ts->mutex);
417 * Test TSC2005 communications via temp high register.
421 tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high_orig);
422 temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
423 tsc2005_write(ts, TSC2005_REG_TEMP_HIGH, temp_high_test);
424 tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
425 if (temp_high != temp_high_test) {
426 dev_warn(dev, "selftest failed: %d != %d\n",
427 temp_high, temp_high_test);
433 usleep_range(100, 500); /* only 10us required */
437 /* test that the reset really happened */
438 tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
439 if (temp_high != temp_high_orig) {
440 dev_warn(dev, "selftest failed after reset: %d != %d\n",
441 temp_high, temp_high_orig);
445 mutex_unlock(&ts->mutex);
447 return sprintf(buf, "%u\n", result);
450 static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL);
452 static struct attribute *tsc2005_attrs[] = {
453 &dev_attr_disable.attr,
454 &dev_attr_selftest.attr,
458 static mode_t tsc2005_attr_is_visible(struct kobject *kobj,
459 struct attribute *attr, int n)
461 struct device *dev = container_of(kobj, struct device, kobj);
462 struct spi_device *spi = to_spi_device(dev);
463 struct tsc2005 *ts = spi_get_drvdata(spi);
464 mode_t mode = attr->mode;
466 if (attr == &dev_attr_selftest.attr) {
474 static const struct attribute_group tsc2005_attr_group = {
475 .is_visible = tsc2005_attr_is_visible,
476 .attrs = tsc2005_attrs,
479 static void tsc2005_esd_timer(unsigned long data)
481 struct tsc2005 *ts = (struct tsc2005 *)data;
483 schedule_work(&ts->esd_work);
486 static void tsc2005_esd_work(struct work_struct *work)
488 struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work);
491 mutex_lock(&ts->mutex);
493 if (ts->disable_depth)
497 * If we cannot read our known value from configuration register 0 then
498 * reset the controller as if from power-up and start scanning again.
500 tsc2005_read(ts, TSC2005_REG_CFR0, &r);
501 if ((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK) {
502 dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n");
504 tsc2005_update_pen_state(ts, 0, 0, 0);
505 usleep_range(100, 500); /* only 10us required */
507 tsc2005_start_scan(ts);
510 /* re-arm the watchdog */
511 mod_timer(&ts->esd_timer,
512 round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout)));
515 mutex_unlock(&ts->mutex);
518 static void __devinit tsc2005_setup_spi_xfer(struct tsc2005 *ts)
520 tsc2005_setup_read(&ts->spi_x, TSC2005_REG_X, 0);
521 tsc2005_setup_read(&ts->spi_y, TSC2005_REG_Y, 0);
522 tsc2005_setup_read(&ts->spi_z1, TSC2005_REG_Z1, 0);
523 tsc2005_setup_read(&ts->spi_z2, TSC2005_REG_Z2, 1);
525 spi_message_init(&ts->spi_read_msg);
526 spi_message_add_tail(&ts->spi_x.spi_xfer, &ts->spi_read_msg);
527 spi_message_add_tail(&ts->spi_y.spi_xfer, &ts->spi_read_msg);
528 spi_message_add_tail(&ts->spi_z1.spi_xfer, &ts->spi_read_msg);
529 spi_message_add_tail(&ts->spi_z2.spi_xfer, &ts->spi_read_msg);
532 static int __devinit tsc2005_probe(struct spi_device *spi)
534 const struct tsc2005_platform_data *pdata = spi->dev.platform_data;
536 struct input_dev *input_dev;
537 unsigned int max_x, max_y, max_p;
538 unsigned int fudge_x, fudge_y, fudge_p;
542 dev_dbg(&spi->dev, "no platform data\n");
546 fudge_x = pdata->ts_x_fudge ? : 4;
547 fudge_y = pdata->ts_y_fudge ? : 8;
548 fudge_p = pdata->ts_pressure_fudge ? : 2;
549 max_x = pdata->ts_x_max ? : MAX_12BIT;
550 max_y = pdata->ts_y_max ? : MAX_12BIT;
551 max_p = pdata->ts_pressure_max ? : MAX_12BIT;
554 dev_dbg(&spi->dev, "no irq\n");
558 spi->mode = SPI_MODE_0;
559 spi->bits_per_word = 8;
560 if (!spi->max_speed_hz)
561 spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ;
563 error = spi_setup(spi);
567 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
568 input_dev = input_allocate_device();
569 if (!ts || !input_dev) {
575 ts->idev = input_dev;
577 ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280;
578 ts->esd_timeout = pdata->esd_timeout_ms;
579 ts->set_reset = pdata->set_reset;
581 mutex_init(&ts->mutex);
583 setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts);
584 INIT_WORK(&ts->penup_work, tsc2005_penup_work);
586 setup_timer(&ts->esd_timer, tsc2005_esd_timer, (unsigned long)ts);
587 INIT_WORK(&ts->esd_work, tsc2005_esd_work);
589 tsc2005_setup_spi_xfer(ts);
591 snprintf(ts->phys, sizeof(ts->phys),
592 "%s/input-ts", dev_name(&spi->dev));
594 input_dev->name = "TSC2005 touchscreen";
595 input_dev->phys = ts->phys;
596 input_dev->id.bustype = BUS_SPI;
597 input_dev->dev.parent = &spi->dev;
598 input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
599 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
601 input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
602 input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
603 input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
605 error = request_threaded_irq(spi->irq,
606 tsc2005_irq_handler, tsc2005_irq_thread,
607 IRQF_TRIGGER_RISING, "tsc2005", ts);
609 dev_err(&spi->dev, "Failed to request irq, err: %d\n", error);
613 spi_set_drvdata(spi, ts);
614 error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group);
617 "Failed to create sysfs attributes, err: %d\n", error);
618 goto err_clear_drvdata;
621 error = input_register_device(ts->idev);
624 "Failed to register input device, err: %d\n", error);
625 goto err_remove_sysfs;
628 tsc2005_start_scan(ts);
630 if (ts->esd_timeout && ts->set_reset) {
631 /* start the optional ESD watchdog */
632 mod_timer(&ts->esd_timer, round_jiffies(jiffies +
633 msecs_to_jiffies(ts->esd_timeout)));
636 set_irq_wake(spi->irq, 1);
640 sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
642 spi_set_drvdata(spi, NULL);
643 free_irq(spi->irq, ts);
645 input_free_device(input_dev);
650 static int __devexit tsc2005_remove(struct spi_device *spi)
652 struct tsc2005 *ts = spi_get_drvdata(spi);
654 sysfs_remove_group(&ts->spi->dev.kobj, &tsc2005_attr_group);
656 mutex_lock(&ts->mutex);
658 mutex_unlock(&ts->mutex);
661 del_timer_sync(&ts->esd_timer);
662 del_timer_sync(&ts->penup_timer);
664 flush_work(&ts->esd_work);
665 flush_work(&ts->penup_work);
667 free_irq(ts->spi->irq, ts);
668 input_unregister_device(ts->idev);
671 spi_set_drvdata(spi, NULL);
675 #ifdef CONFIG_PM_SLEEP
676 static int tsc2005_suspend(struct device *dev)
678 struct spi_device *spi = to_spi_device(dev);
679 struct tsc2005 *ts = spi_get_drvdata(spi);
681 mutex_lock(&ts->mutex);
683 mutex_unlock(&ts->mutex);
688 static int tsc2005_resume(struct device *dev)
690 struct spi_device *spi = to_spi_device(dev);
691 struct tsc2005 *ts = spi_get_drvdata(spi);
693 mutex_lock(&ts->mutex);
695 mutex_unlock(&ts->mutex);
701 static SIMPLE_DEV_PM_OPS(tsc2005_pm_ops, tsc2005_suspend, tsc2005_resume);
703 static struct spi_driver tsc2005_driver = {
706 .owner = THIS_MODULE,
707 .pm = &tsc2005_pm_ops,
709 .probe = tsc2005_probe,
710 .remove = __devexit_p(tsc2005_remove),
713 static int __init tsc2005_init(void)
715 return spi_register_driver(&tsc2005_driver);
717 module_init(tsc2005_init);
719 static void __exit tsc2005_exit(void)
721 spi_unregister_driver(&tsc2005_driver);
723 module_exit(tsc2005_exit);
725 MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
726 MODULE_DESCRIPTION("TSC2005 Touchscreen Driver");
727 MODULE_LICENSE("GPL");