2 * TSC2005 touchscreen driver
4 * Copyright (C) 2006-2008 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>
30 #include <linux/gpio.h>
31 #include <linux/spi/spi.h>
33 #include <linux/spi/tsc2005.h>
36 * The touchscreen interface operates as follows:
39 * Request access to GPIO103 (DAV)
40 * tsc2005_dav_irq_handler will trigger when DAV line goes down
42 * 1) Pen is pressed against touchscreeen
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_dav_irq_handler is called
46 * 5) tsc2005_ts_irq_handler queues up an spi transfer to fetch
47 * the x, y, z1, z2 values
48 * 6) tsc2005_ts_rx() reports coordinates to input layer and
49 * sets up tsc2005_ts_timer() to be called after TSC2005_TS_SCAN_TIME
50 * 7) When the penup_timer expires, there have not been DAV interrupts
51 * during the last 20ms which means the pen has been lifted.
54 #define TSC2005_VDD_LOWER_27
56 #ifdef TSC2005_VDD_LOWER_27
57 #define TSC2005_HZ (10000000)
59 #define TSC2005_HZ (25000000)
62 #define TSC2005_CMD (0x80)
63 #define TSC2005_REG (0x00)
65 #define TSC2005_CMD_STOP (1)
66 #define TSC2005_CMD_10BIT (0 << 2)
67 #define TSC2005_CMD_12BIT (1 << 2)
69 #define TSC2005_CMD_SCAN_XYZZ (0 << 3)
70 #define TSC2005_CMD_SCAN_XY (1 << 3)
71 #define TSC2005_CMD_SCAN_X (2 << 3)
72 #define TSC2005_CMD_SCAN_Y (3 << 3)
73 #define TSC2005_CMD_SCAN_ZZ (4 << 3)
74 #define TSC2005_CMD_AUX_SINGLE (5 << 3)
75 #define TSC2005_CMD_TEMP1 (6 << 3)
76 #define TSC2005_CMD_TEMP2 (7 << 3)
77 #define TSC2005_CMD_AUX_CONT (8 << 3)
78 #define TSC2005_CMD_TEST_X_CONN (9 << 3)
79 #define TSC2005_CMD_TEST_Y_CONN (10 << 3)
80 /* command 11 reserved */
81 #define TSC2005_CMD_TEST_SHORT (12 << 3)
82 #define TSC2005_CMD_DRIVE_XX (13 << 3)
83 #define TSC2005_CMD_DRIVE_YY (14 << 3)
84 #define TSC2005_CMD_DRIVE_YX (15 << 3)
86 #define TSC2005_REG_X (0 << 3)
87 #define TSC2005_REG_Y (1 << 3)
88 #define TSC2005_REG_Z1 (2 << 3)
89 #define TSC2005_REG_Z2 (3 << 3)
90 #define TSC2005_REG_AUX (4 << 3)
91 #define TSC2005_REG_TEMP1 (5 << 3)
92 #define TSC2005_REG_TEMP2 (6 << 3)
93 #define TSC2005_REG_STATUS (7 << 3)
94 #define TSC2005_REG_AUX_HIGH (8 << 3)
95 #define TSC2005_REG_AUX_LOW (9 << 3)
96 #define TSC2005_REG_TEMP_HIGH (10 << 3)
97 #define TSC2005_REG_TEMP_LOW (11 << 3)
98 #define TSC2005_REG_CFR0 (12 << 3)
99 #define TSC2005_REG_CFR1 (13 << 3)
100 #define TSC2005_REG_CFR2 (14 << 3)
101 #define TSC2005_REG_FUNCTION (15 << 3)
103 #define TSC2005_REG_PND0 (1 << 1)
104 #define TSC2005_REG_READ (0x01)
105 #define TSC2005_REG_WRITE (0x00)
108 #define TSC2005_CFR0_LONGSAMPLING (1)
109 #define TSC2005_CFR0_DETECTINWAIT (1 << 1)
110 #define TSC2005_CFR0_SENSETIME_32US (0)
111 #define TSC2005_CFR0_SENSETIME_96US (1 << 2)
112 #define TSC2005_CFR0_SENSETIME_544US (1 << 3)
113 #define TSC2005_CFR0_SENSETIME_2080US (1 << 4)
114 #define TSC2005_CFR0_SENSETIME_2656US (0x001C)
115 #define TSC2005_CFR0_PRECHARGE_20US (0x0000)
116 #define TSC2005_CFR0_PRECHARGE_84US (0x0020)
117 #define TSC2005_CFR0_PRECHARGE_276US (0x0040)
118 #define TSC2005_CFR0_PRECHARGE_1044US (0x0080)
119 #define TSC2005_CFR0_PRECHARGE_1364US (0x00E0)
120 #define TSC2005_CFR0_STABTIME_0US (0x0000)
121 #define TSC2005_CFR0_STABTIME_100US (0x0100)
122 #define TSC2005_CFR0_STABTIME_500US (0x0200)
123 #define TSC2005_CFR0_STABTIME_1MS (0x0300)
124 #define TSC2005_CFR0_STABTIME_5MS (0x0400)
125 #define TSC2005_CFR0_STABTIME_100MS (0x0700)
126 #define TSC2005_CFR0_CLOCK_4MHZ (0x0000)
127 #define TSC2005_CFR0_CLOCK_2MHZ (0x0800)
128 #define TSC2005_CFR0_CLOCK_1MHZ (0x1000)
129 #define TSC2005_CFR0_RESOLUTION12 (0x2000)
130 #define TSC2005_CFR0_STATUS (0x4000)
131 #define TSC2005_CFR0_PENMODE (0x8000)
133 #define TSC2005_CFR0_INITVALUE (TSC2005_CFR0_STABTIME_1MS | \
134 TSC2005_CFR0_CLOCK_1MHZ | \
135 TSC2005_CFR0_RESOLUTION12 | \
136 TSC2005_CFR0_PRECHARGE_276US | \
137 TSC2005_CFR0_PENMODE)
139 #define TSC2005_CFR1_BATCHDELAY_0MS (0x0000)
140 #define TSC2005_CFR1_BATCHDELAY_1MS (0x0001)
141 #define TSC2005_CFR1_BATCHDELAY_2MS (0x0002)
142 #define TSC2005_CFR1_BATCHDELAY_4MS (0x0003)
143 #define TSC2005_CFR1_BATCHDELAY_10MS (0x0004)
144 #define TSC2005_CFR1_BATCHDELAY_20MS (0x0005)
145 #define TSC2005_CFR1_BATCHDELAY_40MS (0x0006)
146 #define TSC2005_CFR1_BATCHDELAY_100MS (0x0007)
148 #define TSC2005_CFR1_INITVALUE (TSC2005_CFR1_BATCHDELAY_2MS)
150 #define TSC2005_CFR2_MAVE_TEMP (0x0001)
151 #define TSC2005_CFR2_MAVE_AUX (0x0002)
152 #define TSC2005_CFR2_MAVE_Z (0x0004)
153 #define TSC2005_CFR2_MAVE_Y (0x0008)
154 #define TSC2005_CFR2_MAVE_X (0x0010)
155 #define TSC2005_CFR2_AVG_1 (0x0000)
156 #define TSC2005_CFR2_AVG_3 (0x0400)
157 #define TSC2005_CFR2_AVG_7 (0x0800)
158 #define TSC2005_CFR2_MEDIUM_1 (0x0000)
159 #define TSC2005_CFR2_MEDIUM_3 (0x1000)
160 #define TSC2005_CFR2_MEDIUM_7 (0x2000)
161 #define TSC2005_CFR2_MEDIUM_15 (0x3000)
163 #define TSC2005_CFR2_IRQ_DAV (0x4000)
164 #define TSC2005_CFR2_IRQ_PEN (0x8000)
165 #define TSC2005_CFR2_IRQ_PENDAV (0x0000)
167 #define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_IRQ_DAV | \
168 TSC2005_CFR2_MAVE_X | \
169 TSC2005_CFR2_MAVE_Y | \
170 TSC2005_CFR2_MAVE_Z | \
171 TSC2005_CFR2_MEDIUM_15 | \
174 #define MAX_12BIT ((1 << 12) - 1)
176 #define TS_RECT_SIZE 8
177 #define TSC2005_TS_PENUP_TIME 20
179 static const u32 tsc2005_read_reg[] = {
180 (TSC2005_REG | TSC2005_REG_X | TSC2005_REG_READ) << 16,
181 (TSC2005_REG | TSC2005_REG_Y | TSC2005_REG_READ) << 16,
182 (TSC2005_REG | TSC2005_REG_Z1 | TSC2005_REG_READ) << 16,
183 (TSC2005_REG | TSC2005_REG_Z2 | TSC2005_REG_READ) << 16,
185 #define NUM_READ_REGS (sizeof(tsc2005_read_reg)/sizeof(tsc2005_read_reg[0]))
188 struct spi_device *spi;
190 struct input_dev *idev;
192 struct timer_list penup_timer;
196 struct spi_message read_msg;
197 struct spi_transfer read_xfer[NUM_READ_REGS];
198 u32 data[NUM_READ_REGS];
204 /* average accumulators for each component */
226 static void tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
228 u16 data = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
229 struct spi_message msg;
230 struct spi_transfer xfer = { 0 };
235 xfer.bits_per_word = 8;
237 spi_message_init(&msg);
238 spi_message_add_tail(&xfer, &msg);
239 spi_sync(ts->spi, &msg);
242 static void tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value)
245 struct spi_message msg;
246 struct spi_transfer xfer = { 0 };
248 tx = (TSC2005_REG | reg | TSC2005_REG_PND0 |
249 TSC2005_REG_WRITE) << 16;
255 xfer.bits_per_word = 24;
257 spi_message_init(&msg);
258 spi_message_add_tail(&xfer, &msg);
259 spi_sync(ts->spi, &msg);
262 static void tsc2005_ts_update_pen_state(struct tsc2005 *ts,
263 int x, int y, int pressure)
266 input_report_abs(ts->idev, ABS_X, x);
267 input_report_abs(ts->idev, ABS_Y, y);
268 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
270 input_report_key(ts->idev, BTN_TOUCH, 1);
274 input_report_abs(ts->idev, ABS_PRESSURE, 0);
276 input_report_key(ts->idev, BTN_TOUCH, 0);
281 input_sync(ts->idev);
285 * This function is called by the SPI framework after the coordinates
286 * have been read from TSC2005
288 static void tsc2005_ts_rx(void *arg)
290 struct tsc2005 *ts = arg;
292 int inside_rect, pressure_limit;
293 int x, y, z1, z2, pressure;
295 spin_lock_irqsave(&ts->lock, flags);
302 /* validate pressure and position */
303 if (x > MAX_12BIT || y > MAX_12BIT)
306 /* skip coords if the pressure-components are out of range */
307 if (z1 < 100 || z2 > 4000)
310 /* don't run average on the "pen down" event */
311 if (ts->sample_sent) {
317 if (++ts->sample_cnt < TS_SAMPLES)
320 x = ts->avg_x / TS_SAMPLES;
321 y = ts->avg_y / TS_SAMPLES;
322 z1 = ts->avg_z1 / TS_SAMPLES;
323 z2 = ts->avg_z2 / TS_SAMPLES;
333 pressure = x * (z2 - z1) / z1;
334 pressure = pressure * ts->x_plate_ohm / 4096;
338 pressure_limit = ts->sample_sent? ts->p_max: ts->touch_pressure;
339 if (pressure > pressure_limit)
342 /* discard the event if it still is within the previous rect - unless
343 * if the pressure is harder, but then use previous x,y position */
344 inside_rect = (ts->sample_sent &&
345 x > (int)ts->x - TS_RECT_SIZE &&
346 x < (int)ts->x + TS_RECT_SIZE &&
347 y > (int)ts->y - TS_RECT_SIZE &&
348 y < (int)ts->y + TS_RECT_SIZE);
350 x = ts->x, y = ts->y;
352 if (!inside_rect || pressure < ts->p) {
353 tsc2005_ts_update_pen_state(ts, x, y, pressure);
361 spin_unlock_irqrestore(&ts->lock, flags);
363 /* kick pen up timer - to make sure it expires again(!) */
365 mod_timer(&ts->penup_timer,
366 jiffies + msecs_to_jiffies(TSC2005_TS_PENUP_TIME));
369 static void tsc2005_ts_penup_timer_handler(unsigned long data)
371 struct tsc2005 *ts = (struct tsc2005 *)data;
373 if (ts->sample_sent) {
374 tsc2005_ts_update_pen_state(ts, 0, 0, 0);
380 * This interrupt is called when pen is down and coordinates are
381 * available. That is indicated by a falling edge on DAV line.
383 static irqreturn_t tsc2005_ts_irq_handler(int irq, void *dev_id)
385 struct tsc2005 *ts = dev_id;
392 r = spi_async(ts->spi, &ts->read_msg);
394 dev_err(&ts->spi->dev, "ts: spi_async() failed");
396 /* kick pen up timer */
397 mod_timer(&ts->penup_timer,
398 jiffies + msecs_to_jiffies(TSC2005_TS_PENUP_TIME));
403 static void tsc2005_ts_setup_spi_xfer(struct tsc2005 *ts)
405 struct spi_message *m = &ts->read_msg;
406 struct spi_transfer *x = &ts->read_xfer[0];
411 for (i = 0; i < NUM_READ_REGS; i++, x++) {
412 x->tx_buf = &tsc2005_read_reg[i];
413 x->rx_buf = &ts->data[i];
415 x->bits_per_word = 24;
416 x->cs_change = i < (NUM_READ_REGS - 1);
417 spi_message_add_tail(x, m);
420 m->complete = tsc2005_ts_rx;
424 static ssize_t tsc2005_ts_pen_down_show(struct device *dev,
425 struct device_attribute *attr,
428 struct tsc2005 *tsc = dev_get_drvdata(dev);
430 return sprintf(buf, "%u\n", tsc->pen_down);
433 static DEVICE_ATTR(pen_down, S_IRUGO, tsc2005_ts_pen_down_show, NULL);
435 static int tsc2005_configure(struct tsc2005 *tsc, int flags)
437 tsc2005_write(tsc, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE);
438 tsc2005_write(tsc, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE);
439 tsc2005_write(tsc, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE);
440 tsc2005_cmd(tsc, flags);
445 static void tsc2005_start_scan(struct tsc2005 *tsc)
447 tsc2005_configure(tsc, TSC2005_CMD_SCAN_XYZZ);
450 static void tsc2005_stop_scan(struct tsc2005 *tsc)
452 tsc2005_cmd(tsc, TSC2005_CMD_STOP);
455 /* Must be called with mutex held */
456 static void tsc2005_disable(struct tsc2005 *ts)
458 if (ts->disable_depth++ != 0)
461 disable_irq(ts->irq);
463 /* wait until penup timer expire normally */
466 } while (ts->sample_sent);
468 tsc2005_stop_scan(ts);
471 static void tsc2005_enable(struct tsc2005 *ts)
473 if (--ts->disable_depth != 0)
478 tsc2005_start_scan(ts);
481 static ssize_t tsc2005_disable_show(struct device *dev,
482 struct device_attribute *attr, char *buf)
484 struct tsc2005 *ts = dev_get_drvdata(dev);
486 return sprintf(buf, "%u\n", ts->disabled);
489 static ssize_t tsc2005_disable_store(struct device *dev,
490 struct device_attribute *attr,
491 const char *buf, size_t count)
493 struct tsc2005 *tsc = dev_get_drvdata(dev);
497 i = strict_strtoul(buf, 10, &res);
500 mutex_lock(&tsc->mutex);
501 if (i == tsc->disabled)
506 tsc2005_disable(tsc);
510 mutex_unlock(&tsc->mutex);
514 static DEVICE_ATTR(disable_ts, 0664, tsc2005_disable_show,
515 tsc2005_disable_store);
518 static int __devinit tsc2005_ts_init(struct tsc2005 *ts,
519 struct tsc2005_platform_data *pdata)
521 struct input_dev *idev;
524 int x_fudge, y_fudge, p_fudge;
526 if (pdata->dav_gpio < 0) {
527 dev_err(&ts->spi->dev, "need DAV GPIO");
530 dav_gpio = pdata->dav_gpio;
531 ts->dav_gpio = dav_gpio;
532 dev_dbg(&ts->spi->dev, "TSC2005: DAV GPIO = %d\n", dav_gpio);
534 r = gpio_request(dav_gpio, "TSC2005 dav");
536 dev_err(&ts->spi->dev, "unable to get DAV GPIO");
539 gpio_direction_input(dav_gpio);
540 ts->irq = gpio_to_irq(dav_gpio);
541 dev_dbg(&ts->spi->dev, "TSC2005: DAV IRQ = %d\n", ts->irq);
543 init_timer(&ts->penup_timer);
544 setup_timer(&ts->penup_timer, tsc2005_ts_penup_timer_handler,
547 spin_lock_init(&ts->lock);
548 mutex_init(&ts->mutex);
550 ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280;
551 ts->hw_avg_max = pdata->ts_hw_avg;
552 ts->stab_time = pdata->ts_stab_time;
553 x_max = pdata->ts_x_max ? : 4096;
554 x_fudge = pdata->ts_x_fudge ? : 4;
555 y_max = pdata->ts_y_max ? : 4096;
556 y_fudge = pdata->ts_y_fudge ? : 8;
557 ts->p_max = pdata->ts_pressure_max ? : MAX_12BIT;
558 ts->touch_pressure = pdata->ts_touch_pressure ? : ts->p_max;
559 p_fudge = pdata->ts_pressure_fudge ? : 2;
561 idev = input_allocate_device();
567 idev->name = "TSC2005 touchscreen";
568 snprintf(ts->phys, sizeof(ts->phys), "%s/input-ts",
569 ts->spi->dev.bus_id);
570 idev->phys = ts->phys;
572 idev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
573 idev->absbit[0] = BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE);
576 tsc2005_ts_setup_spi_xfer(ts);
578 input_set_abs_params(idev, ABS_X, 0, x_max, x_fudge, 0);
579 input_set_abs_params(idev, ABS_Y, 0, y_max, y_fudge, 0);
580 input_set_abs_params(idev, ABS_PRESSURE, 0, ts->p_max, p_fudge, 0);
582 tsc2005_start_scan(ts);
584 r = request_irq(ts->irq, tsc2005_ts_irq_handler,
585 IRQF_TRIGGER_FALLING | IRQF_DISABLED |
586 IRQF_SAMPLE_RANDOM, "tsc2005", ts);
588 dev_err(&ts->spi->dev, "unable to get DAV IRQ");
592 set_irq_wake(ts->irq, 1);
594 r = input_register_device(idev);
596 dev_err(&ts->spi->dev, "can't register touchscreen device\n");
600 /* We can tolerate these failing */
601 if (device_create_file(&ts->spi->dev, &dev_attr_pen_down));
602 if (device_create_file(&ts->spi->dev, &dev_attr_disable_ts));
606 free_irq(ts->irq, ts);
608 tsc2005_stop_scan(ts);
609 input_free_device(idev);
616 static int __devinit tsc2005_probe(struct spi_device *spi)
619 struct tsc2005_platform_data *pdata = spi->dev.platform_data;
623 dev_dbg(&spi->dev, "no platform data?\n");
627 tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
631 dev_set_drvdata(&spi->dev, tsc);
633 spi->dev.power.power_state = PMSG_ON;
635 spi->mode = SPI_MODE_0;
636 spi->bits_per_word = 8;
637 /* The max speed might've been defined by the board-specific
639 if (!spi->max_speed_hz)
640 spi->max_speed_hz = TSC2005_HZ;
644 r = tsc2005_ts_init(tsc, pdata);
655 static int __devexit tsc2005_remove(struct spi_device *spi)
657 struct tsc2005 *ts = dev_get_drvdata(&spi->dev);
659 mutex_lock(&ts->mutex);
661 mutex_unlock(&ts->mutex);
663 device_remove_file(&ts->spi->dev, &dev_attr_disable_ts);
664 device_remove_file(&ts->spi->dev, &dev_attr_pen_down);
666 free_irq(ts->irq, ts);
667 input_unregister_device(ts->idev);
669 gpio_free(ts->dav_gpio);
676 static int tsc2005_suspend(struct spi_device *spi, pm_message_t mesg)
678 struct tsc2005 *ts = dev_get_drvdata(&spi->dev);
680 mutex_lock(&ts->mutex);
682 mutex_unlock(&ts->mutex);
687 static int tsc2005_resume(struct spi_device *spi)
689 struct tsc2005 *ts = dev_get_drvdata(&spi->dev);
691 mutex_lock(&ts->mutex);
693 mutex_unlock(&ts->mutex);
699 static struct spi_driver tsc2005_driver = {
702 .owner = THIS_MODULE,
705 .suspend = tsc2005_suspend,
706 .resume = tsc2005_resume,
708 .probe = tsc2005_probe,
709 .remove = __devexit_p(tsc2005_remove),
712 static int __init tsc2005_init(void)
714 printk(KERN_INFO "TSC2005 driver initializing\n");
716 return spi_register_driver(&tsc2005_driver);
718 module_init(tsc2005_init);
720 static void __exit tsc2005_exit(void)
722 spi_unregister_driver(&tsc2005_driver);
724 module_exit(tsc2005_exit);
726 MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
727 MODULE_LICENSE("GPL");
728 MODULE_ALIAS("platform:tsc2005");