2 * TSC2301 touchscreen driver
4 * Copyright (C) 2005-2008 Nokia Corporation
6 * Written by Jarkko Oikarinen, Imre Deak and Juha Yrjola
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/input.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/spi/spi.h>
31 #ifdef CONFIG_ARCH_OMAP
32 #include <asm/arch/gpio.h>
35 #include <linux/spi/tsc2301.h>
38 * The touchscreen interface operates as follows:
41 * Request access to GPIO103 (DAV)
42 * tsc2301_ts_irq_handler will trigger when DAV line goes down
44 * 1) Pen is pressed against touchscreeen
45 * 2) TSC2301 performs AD conversion
46 * 3) After the conversion is done TSC2301 drives DAV line down
47 * 4) GPIO IRQ is received and tsc2301_ts_irq_handler is called
48 * 5) tsc2301_ts_irq_handler queues up an spi transfer to fetch
49 * the x, y, z1, z2 values
50 * 6) SPI framework calls tsc2301_ts_rx after the coordinates are read
51 * 7) When the penup_timer expires, there have not been DAV interrupts
52 * during the last 20ms which means the pen has been lifted.
56 #define TSC2301_TOUCHSCREEN_PRODUCT_ID 0x0052
57 #define TSC2301_TOUCHSCREEN_PRODUCT_VERSION 0x0001
59 #define TSC2301_TS_PENUP_TIME 20
61 #define TSC2301_ADCREG_CONVERSION_CTRL_BY_TSC2301 0x8000
62 #define TSC2301_ADCREG_CONVERSION_CTRL_BY_HOST 0x0000
64 #define TSC2301_ADCREG_FUNCTION_NONE 0x0000
65 #define TSC2301_ADCREG_FUNCTION_XY 0x0400
66 #define TSC2301_ADCREG_FUNCTION_XYZ 0x0800
67 #define TSC2301_ADCREG_FUNCTION_X 0x0C00
68 #define TSC2301_ADCREG_FUNCTION_Y 0x1000
69 #define TSC2301_ADCREG_FUNCTION_Z 0x1400
70 #define TSC2301_ADCREG_FUNCTION_DAT1 0x1800
71 #define TSC2301_ADCREG_FUNCTION_DAT2 0x1C00
72 #define TSC2301_ADCREG_FUNCTION_AUX1 0x2000
73 #define TSC2301_ADCREG_FUNCTION_AUX2 0x2400
74 #define TSC2301_ADCREG_FUNCTION_TEMP 0x2800
76 #define TSC2301_ADCREG_RESOLUTION_8BIT 0x0100
77 #define TSC2301_ADCREG_RESOLUTION_10BIT 0x0200
78 #define TSC2301_ADCREG_RESOLUTION_12BIT 0x0300
80 #define TSC2301_ADCREG_AVERAGING_NONE 0x0000
81 #define TSC2301_ADCREG_AVERAGING_4AVG 0x0040
82 #define TSC2301_ADCREG_AVERAGING_8AVG 0x0080
83 #define TSC2301_ADCREG_AVERAGING_16AVG 0x00C0
85 #define TSC2301_ADCREG_CLOCK_8MHZ 0x0000
86 #define TSC2301_ADCREG_CLOCK_4MHZ 0x0010
87 #define TSC2301_ADCREG_CLOCK_2MHZ 0x0020
88 #define TSC2301_ADCREG_CLOCK_1MHZ 0x0030
90 #define TSC2301_ADCREG_VOLTAGE_STAB_0US 0x0000
91 #define TSC2301_ADCREG_VOLTAGE_STAB_100US 0x0002
92 #define TSC2301_ADCREG_VOLTAGE_STAB_500US 0x0004
93 #define TSC2301_ADCREG_VOLTAGE_STAB_1MS 0x0006
94 #define TSC2301_ADCREG_VOLTAGE_STAB_5MS 0x0008
95 #define TSC2301_ADCREG_VOLTAGE_STAB_10MS 0x000A
96 #define TSC2301_ADCREG_VOLTAGE_STAB_50MS 0x000C
97 #define TSC2301_ADCREG_VOLTAGE_STAB_100MS 0x000E
99 #define TSC2301_ADCREG_STOP_CONVERSION 0x4000
101 #define MAX_12BIT ((1 << 12) - 1)
104 struct input_dev *idev;
106 struct timer_list penup_timer;
109 struct spi_transfer read_xfer[2];
110 struct spi_message read_msg;
136 static const u16 tsc2301_ts_read_data = 0x8000 | TSC2301_REG_X;
138 static int tsc2301_ts_check_config(struct tsc2301_ts *ts, int *hw_flags)
143 switch (ts->hw_avg_max) {
145 flags |= TSC2301_ADCREG_AVERAGING_NONE;
148 flags |= TSC2301_ADCREG_AVERAGING_4AVG;
151 flags |= TSC2301_ADCREG_AVERAGING_8AVG;
154 flags |= TSC2301_ADCREG_AVERAGING_16AVG;
160 switch (ts->stab_time) {
162 flags |= TSC2301_ADCREG_VOLTAGE_STAB_0US;
165 flags |= TSC2301_ADCREG_VOLTAGE_STAB_100US;
168 flags |= TSC2301_ADCREG_VOLTAGE_STAB_500US;
171 flags |= TSC2301_ADCREG_VOLTAGE_STAB_1MS;
174 flags |= TSC2301_ADCREG_VOLTAGE_STAB_5MS;
177 flags |= TSC2301_ADCREG_VOLTAGE_STAB_10MS;
180 flags |= TSC2301_ADCREG_VOLTAGE_STAB_50MS;
183 flags |= TSC2301_ADCREG_VOLTAGE_STAB_100MS;
194 * This odd three-time initialization is to work around a bug in TSC2301.
195 * See TSC2301 errata for details.
197 static int tsc2301_ts_configure(struct tsc2301 *tsc, int flags)
199 struct spi_transfer xfer[5];
200 struct spi_transfer *x;
201 struct spi_message m;
203 u16 val1, val2, val3;
206 val1 = TSC2301_ADCREG_CONVERSION_CTRL_BY_HOST |
207 TSC2301_ADCREG_STOP_CONVERSION |
208 TSC2301_ADCREG_FUNCTION_NONE |
209 TSC2301_ADCREG_RESOLUTION_12BIT |
210 TSC2301_ADCREG_AVERAGING_NONE |
211 TSC2301_ADCREG_CLOCK_2MHZ |
212 TSC2301_ADCREG_VOLTAGE_STAB_100MS;
214 val2 = TSC2301_ADCREG_CONVERSION_CTRL_BY_HOST |
215 TSC2301_ADCREG_FUNCTION_XYZ |
216 TSC2301_ADCREG_RESOLUTION_12BIT |
217 TSC2301_ADCREG_AVERAGING_16AVG |
218 TSC2301_ADCREG_CLOCK_1MHZ |
219 TSC2301_ADCREG_VOLTAGE_STAB_100MS;
221 /* Averaging and voltage stabilization settings in flags */
222 val3 = TSC2301_ADCREG_CONVERSION_CTRL_BY_TSC2301 |
223 TSC2301_ADCREG_FUNCTION_XYZ |
224 TSC2301_ADCREG_RESOLUTION_12BIT |
225 TSC2301_ADCREG_CLOCK_2MHZ |
228 /* Now we prepare the command for transferring */
229 data[0] = TSC2301_REG_ADC;
231 data[2] = TSC2301_REG_ADC;
233 data[4] = TSC2301_REG_ADC;
235 data[6] = TSC2301_REG_REF;
236 data[7] = 1 << 4 | 1 << 2 | 1; /* intref, 100uS settl, 2.5V ref */
237 data[8] = TSC2301_REG_CONFIG;
238 data[9] = 3 << 3 | 2 << 0; /* 340uS pre-chrg, 544us delay */
240 spi_message_init(&m);
243 memset(xfer, 0, sizeof(xfer));
246 for (i = 0; i < 10; i += 2) {
247 x->tx_buf = &data[i];
251 spi_message_add_tail(x, &m);
259 static void tsc2301_ts_start_scan(struct tsc2301 *tsc)
261 tsc2301_ts_configure(tsc, tsc->ts->hw_flags);
264 static void tsc2301_ts_stop_scan(struct tsc2301 *tsc)
266 tsc2301_write_reg(tsc, TSC2301_REG_ADC, TSC2301_ADCREG_STOP_CONVERSION);
269 static void update_pen_state(struct tsc2301_ts *ts, int x, int y, int pressure)
272 input_report_abs(ts->idev, ABS_X, x);
273 input_report_abs(ts->idev, ABS_Y, y);
274 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
276 input_report_key(ts->idev, BTN_TOUCH, 1);
279 input_report_abs(ts->idev, ABS_PRESSURE, 0);
281 input_report_key(ts->idev, BTN_TOUCH, 0);
285 input_sync(ts->idev);
288 dev_dbg(&tsc->spi->dev, "x %4d y %4d p %4d\n", x, y, pressure);
292 static int filter(struct tsc2301_ts *ts, int x, int y, int z1, int z2)
294 int pressure, pressure_limit;
297 pressure = ts->x_plate_ohm * x;
304 /* If pressure value is above a preset limit (pen is barely
305 * touching the screen) we can't trust the coordinate values.
307 pressure_limit = ts->event_sent? ts->max_pressure: ts->touch_pressure;
309 if (pressure < pressure_limit && x < MAX_12BIT && y < MAX_12BIT) {
319 * This procedure is called by the SPI framework after the coordinates
320 * have been read from TSC2301
322 static void tsc2301_ts_rx(void *arg)
324 struct tsc2301 *tsc = arg;
325 struct tsc2301_ts *ts = tsc->ts;
334 send_event = filter(ts, x, y, z1, z2);
336 update_pen_state(ts, ts->x, ts->y, ts->p);
340 mod_timer(&ts->penup_timer,
341 jiffies + msecs_to_jiffies(TSC2301_TS_PENUP_TIME));
345 * Timer is called TSC2301_TS_PENUP_TIME after pen is up
347 static void tsc2301_ts_timer_handler(unsigned long data)
349 struct tsc2301 *tsc = (struct tsc2301 *)data;
350 struct tsc2301_ts *ts = tsc->ts;
352 if (ts->event_sent) {
354 update_pen_state(ts, 0, 0, 0);
359 * This interrupt is called when pen is down and coordinates are
360 * available. That is indicated by a falling edge on DEV line.
362 static irqreturn_t tsc2301_ts_irq_handler(int irq, void *dev_id)
364 struct tsc2301 *tsc = dev_id;
365 struct tsc2301_ts *ts = tsc->ts;
368 r = spi_async(tsc->spi, &ts->read_msg);
370 dev_err(&tsc->spi->dev, "ts: spi_async() failed");
372 mod_timer(&ts->penup_timer,
373 jiffies + msecs_to_jiffies(TSC2301_TS_PENUP_TIME));
378 static void tsc2301_ts_disable(struct tsc2301 *tsc)
380 struct tsc2301_ts *ts = tsc->ts;
382 if (ts->disable_depth++ != 0)
385 disable_irq(ts->irq);
387 /* wait until penup timer expire normally */
390 } while (ts->event_sent);
392 tsc2301_ts_stop_scan(tsc);
393 /* Workaround a bug where turning on / off touchscreen scanner
394 * can get the keypad scanner stuck.
396 tsc2301_kp_restart(tsc);
399 static void tsc2301_ts_enable(struct tsc2301 *tsc)
401 struct tsc2301_ts *ts = tsc->ts;
403 if (--ts->disable_depth != 0)
408 tsc2301_ts_start_scan(tsc);
409 /* Same workaround as above. */
410 tsc2301_kp_restart(tsc);
414 int tsc2301_ts_suspend(struct tsc2301 *tsc)
416 struct tsc2301_ts *ts = tsc->ts;
418 mutex_lock(&ts->mutex);
419 tsc2301_ts_disable(tsc);
420 mutex_unlock(&ts->mutex);
425 void tsc2301_ts_resume(struct tsc2301 *tsc)
427 struct tsc2301_ts *ts = tsc->ts;
429 mutex_lock(&ts->mutex);
430 tsc2301_ts_enable(tsc);
431 mutex_unlock(&ts->mutex);
435 static void tsc2301_ts_setup_spi_xfer(struct tsc2301 *tsc)
437 struct tsc2301_ts *ts = tsc->ts;
438 struct spi_message *m = &ts->read_msg;
439 struct spi_transfer *x = &ts->read_xfer[0];
443 x->tx_buf = &tsc2301_ts_read_data;
445 spi_message_add_tail(x, m);
448 x->rx_buf = &ts->data;
450 spi_message_add_tail(x, m);
452 m->complete = tsc2301_ts_rx;
456 static ssize_t tsc2301_ts_pen_down_show(struct device *dev,
457 struct device_attribute *attr,
460 struct tsc2301 *tsc = dev_get_drvdata(dev);
462 return sprintf(buf, "%u\n", tsc->ts->pen_down);
465 static DEVICE_ATTR(pen_down, S_IRUGO, tsc2301_ts_pen_down_show, NULL);
467 static ssize_t tsc2301_ts_disable_show(struct device *dev,
468 struct device_attribute *attr, char *buf)
470 struct tsc2301 *tsc = dev_get_drvdata(dev);
471 struct tsc2301_ts *ts = tsc->ts;
473 return sprintf(buf, "%u\n", ts->disabled);
476 static ssize_t tsc2301_ts_disable_store(struct device *dev,
477 struct device_attribute *attr,
478 const char *buf, size_t count)
480 struct tsc2301 *tsc = dev_get_drvdata(dev);
481 struct tsc2301_ts *ts = tsc->ts;
485 i = simple_strtoul(buf, &endp, 10);
487 mutex_lock(&ts->mutex);
488 if (i == ts->disabled) goto out;
492 tsc2301_ts_disable(tsc);
494 tsc2301_ts_enable(tsc);
496 mutex_unlock(&ts->mutex);
500 static DEVICE_ATTR(disable_ts, 0664, tsc2301_ts_disable_show,
501 tsc2301_ts_disable_store);
503 int __devinit tsc2301_ts_init(struct tsc2301 *tsc,
504 struct tsc2301_platform_data *pdata)
506 struct tsc2301_ts *ts;
507 struct input_dev *idev;
510 int x_fudge, y_fudge, p_fudge;
512 if (pdata->dav_gpio < 0) {
513 dev_err(&tsc->spi->dev, "need DAV GPIO");
516 dav_gpio = pdata->dav_gpio;
518 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
523 ts->dav_gpio = dav_gpio;
524 #ifdef CONFIG_ARCH_OMAP
525 r = omap_request_gpio(dav_gpio);
527 dev_err(&tsc->spi->dev, "unable to get DAV GPIO");
530 omap_set_gpio_direction(dav_gpio, 1);
531 ts->irq = OMAP_GPIO_IRQ(dav_gpio);
533 init_timer(&ts->penup_timer);
534 setup_timer(&ts->penup_timer, tsc2301_ts_timer_handler,
537 mutex_init(&ts->mutex);
539 ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280;
540 ts->hw_avg_max = pdata->ts_hw_avg;
541 ts->max_pressure = pdata->ts_max_pressure ? : MAX_12BIT;
542 ts->touch_pressure = pdata->ts_touch_pressure ? : ts->max_pressure;
543 ts->stab_time = pdata->ts_stab_time;
545 x_max = pdata->ts_x_max ? : 4096;
546 y_max = pdata->ts_y_max ? : 4096;
547 x_fudge = pdata->ts_x_fudge ? : 4;
548 y_fudge = pdata->ts_y_fudge ? : 8;
549 p_fudge = pdata->ts_pressure_fudge ? : 2;
551 if ((r = tsc2301_ts_check_config(ts, &ts->hw_flags))) {
552 dev_err(&tsc->spi->dev, "invalid configuration\n");
556 idev = input_allocate_device();
561 idev->name = "TSC2301 touchscreen";
562 snprintf(ts->phys, sizeof(ts->phys),
563 "%s/input-ts", tsc->spi->dev.bus_id);
564 idev->phys = ts->phys;
566 idev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
567 idev->absbit[0] = BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE);
570 tsc2301_ts_setup_spi_xfer(tsc);
572 /* These parameters should perhaps be configurable? */
573 input_set_abs_params(idev, ABS_X, 0, x_max, x_fudge, 0);
574 input_set_abs_params(idev, ABS_Y, 0, y_max, y_fudge, 0);
575 input_set_abs_params(idev, ABS_PRESSURE, 0, ts->max_pressure,
578 tsc2301_ts_start_scan(tsc);
580 r = request_irq(ts->irq, tsc2301_ts_irq_handler,
581 IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_FALLING,
584 dev_err(&tsc->spi->dev, "unable to get DAV IRQ");
587 set_irq_wake(ts->irq, 1);
589 if (device_create_file(&tsc->spi->dev, &dev_attr_pen_down) < 0)
591 if (device_create_file(&tsc->spi->dev, &dev_attr_disable_ts) < 0)
594 r = input_register_device(idev);
596 dev_err(&tsc->spi->dev, "can't register touchscreen device\n");
602 device_remove_file(&tsc->spi->dev, &dev_attr_disable_ts);
604 device_remove_file(&tsc->spi->dev, &dev_attr_pen_down);
606 free_irq(ts->irq, tsc);
608 tsc2301_ts_stop_scan(tsc);
609 input_free_device(idev);
611 #ifdef CONFIG_ARCH_OMAP
612 omap_free_gpio(dav_gpio);
619 void __devexit tsc2301_ts_exit(struct tsc2301 *tsc)
621 struct tsc2301_ts *ts = tsc->ts;
623 tsc2301_ts_disable(tsc);
625 device_remove_file(&tsc->spi->dev, &dev_attr_disable_ts);
626 device_remove_file(&tsc->spi->dev, &dev_attr_pen_down);
628 free_irq(ts->irq, tsc);
629 input_unregister_device(ts->idev);
631 #ifdef CONFIG_ARCH_OMAP
632 omap_free_gpio(ts->dav_gpio);
636 MODULE_AUTHOR("Jarkko Oikarinen <jarkko.oikarinen@nokia.com>");
637 MODULE_LICENSE("GPL");