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ffa458c1 DB |
1 | /* |
2 | * ADS7846 based touchscreen and sensor driver | |
3 | * | |
4 | * Copyright (c) 2005 David Brownell | |
7de90a8c ID |
5 | * Copyright (c) 2006 Nokia Corporation |
6 | * Various changes: Imre Deak <imre.deak@nokia.com> | |
ffa458c1 DB |
7 | * |
8 | * Using code from: | |
9 | * - corgi_ts.c | |
10 | * Copyright (C) 2004-2005 Richard Purdie | |
11 | * - omap_ts.[hc], ads7846.h, ts_osk.c | |
12 | * Copyright (C) 2002 MontaVista Software | |
13 | * Copyright (C) 2004 Texas Instruments | |
14 | * Copyright (C) 2005 Dirk Behme | |
15 | * | |
16 | * This program is free software; you can redistribute it and/or modify | |
17 | * it under the terms of the GNU General Public License version 2 as | |
18 | * published by the Free Software Foundation. | |
19 | */ | |
20 | #include <linux/device.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/delay.h> | |
23 | #include <linux/input.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/spi/spi.h> | |
27 | #include <linux/spi/ads7846.h> | |
3ac8bf07 | 28 | #include <asm/irq.h> |
ffa458c1 DB |
29 | |
30 | #ifdef CONFIG_ARM | |
31 | #include <asm/mach-types.h> | |
32 | #ifdef CONFIG_ARCH_OMAP | |
33 | #include <asm/arch/gpio.h> | |
34 | #endif | |
ffa458c1 DB |
35 | #endif |
36 | ||
37 | ||
38 | /* | |
9084533e DB |
39 | * This code has been heavily tested on a Nokia 770, and lightly |
40 | * tested on other ads7846 devices (OSK/Mistral, Lubbock). | |
ffa458c1 DB |
41 | * Support for ads7843 and ads7845 has only been stubbed in. |
42 | * | |
7de90a8c ID |
43 | * IRQ handling needs a workaround because of a shortcoming in handling |
44 | * edge triggered IRQs on some platforms like the OMAP1/2. These | |
45 | * platforms don't handle the ARM lazy IRQ disabling properly, thus we | |
46 | * have to maintain our own SW IRQ disabled status. This should be | |
47 | * removed as soon as the affected platform's IRQ handling is fixed. | |
48 | * | |
ffa458c1 DB |
49 | * app note sbaa036 talks in more detail about accurate sampling... |
50 | * that ought to help in situations like LCDs inducing noise (which | |
51 | * can also be helped by using synch signals) and more generally. | |
7de90a8c ID |
52 | * This driver tries to utilize the measures described in the app |
53 | * note. The strength of filtering can be set in the board-* specific | |
54 | * files. | |
ffa458c1 DB |
55 | */ |
56 | ||
57 | #define TS_POLL_PERIOD msecs_to_jiffies(10) | |
58 | ||
d93f70b2 DB |
59 | /* this driver doesn't aim at the peak continuous sample rate */ |
60 | #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) | |
61 | ||
ffa458c1 DB |
62 | struct ts_event { |
63 | /* For portability, we can't read 12 bit values using SPI (which | |
64 | * would make the controller deliver them as native byteorder u16 | |
d93f70b2 | 65 | * with msbs zeroed). Instead, we read them as two 8-bit values, |
ffa458c1 DB |
66 | * which need byteswapping then range adjustment. |
67 | */ | |
68 | __be16 x; | |
69 | __be16 y; | |
70 | __be16 z1, z2; | |
d5b415c9 | 71 | int ignore; |
ffa458c1 DB |
72 | }; |
73 | ||
74 | struct ads7846 { | |
a90f7e98 | 75 | struct input_dev *input; |
ffa458c1 DB |
76 | char phys[32]; |
77 | ||
78 | struct spi_device *spi; | |
79 | u16 model; | |
80 | u16 vref_delay_usecs; | |
81 | u16 x_plate_ohms; | |
d5b415c9 | 82 | u16 pressure_max; |
ffa458c1 | 83 | |
53a0ef89 ID |
84 | u8 read_x, read_y, read_z1, read_z2, pwrdown; |
85 | u16 dummy; /* for the pwrdown read */ | |
ffa458c1 DB |
86 | struct ts_event tc; |
87 | ||
53a0ef89 | 88 | struct spi_transfer xfer[10]; |
0b7018aa | 89 | struct spi_message msg[5]; |
d5b415c9 | 90 | struct spi_message *last_msg; |
0b7018aa ID |
91 | int msg_idx; |
92 | int read_cnt; | |
d5b415c9 | 93 | int read_rep; |
0b7018aa ID |
94 | int last_read; |
95 | ||
96 | u16 debounce_max; | |
97 | u16 debounce_tol; | |
d5b415c9 | 98 | u16 debounce_rep; |
ffa458c1 DB |
99 | |
100 | spinlock_t lock; | |
101 | struct timer_list timer; /* P: lock */ | |
102 | unsigned pendown:1; /* P: lock */ | |
103 | unsigned pending:1; /* P: lock */ | |
104 | // FIXME remove "irq_disabled" | |
105 | unsigned irq_disabled:1; /* P: lock */ | |
7de90a8c | 106 | unsigned disabled:1; |
c9e617a5 ID |
107 | |
108 | int (*get_pendown_state)(void); | |
ffa458c1 DB |
109 | }; |
110 | ||
111 | /* leave chip selected when we're done, for quicker re-select? */ | |
112 | #if 0 | |
113 | #define CS_CHANGE(xfer) ((xfer).cs_change = 1) | |
114 | #else | |
115 | #define CS_CHANGE(xfer) ((xfer).cs_change = 0) | |
116 | #endif | |
117 | ||
118 | /*--------------------------------------------------------------------------*/ | |
119 | ||
120 | /* The ADS7846 has touchscreen and other sensors. | |
121 | * Earlier ads784x chips are somewhat compatible. | |
122 | */ | |
123 | #define ADS_START (1 << 7) | |
124 | #define ADS_A2A1A0_d_y (1 << 4) /* differential */ | |
125 | #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ | |
126 | #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ | |
127 | #define ADS_A2A1A0_d_x (5 << 4) /* differential */ | |
128 | #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ | |
129 | #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ | |
130 | #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ | |
131 | #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ | |
132 | #define ADS_8_BIT (1 << 3) | |
133 | #define ADS_12_BIT (0 << 3) | |
134 | #define ADS_SER (1 << 2) /* non-differential */ | |
135 | #define ADS_DFR (0 << 2) /* differential */ | |
136 | #define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */ | |
137 | #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ | |
138 | #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ | |
139 | #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ | |
140 | ||
141 | #define MAX_12BIT ((1<<12)-1) | |
142 | ||
143 | /* leave ADC powered up (disables penirq) between differential samples */ | |
144 | #define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \ | |
145 | | ADS_12_BIT | ADS_DFR) | |
146 | ||
d93f70b2 DB |
147 | #define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON) |
148 | #define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON) | |
149 | #define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON) | |
53a0ef89 ID |
150 | |
151 | #define READ_X (READ_12BIT_DFR(x) | ADS_PD10_ADC_ON) | |
152 | #define PWRDOWN (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) /* LAST */ | |
ffa458c1 DB |
153 | |
154 | /* single-ended samples need to first power up reference voltage; | |
155 | * we leave both ADC and VREF powered | |
156 | */ | |
157 | #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ | |
158 | | ADS_12_BIT | ADS_SER) | |
159 | ||
d93f70b2 DB |
160 | #define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON) |
161 | #define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) | |
ffa458c1 DB |
162 | |
163 | /*--------------------------------------------------------------------------*/ | |
164 | ||
165 | /* | |
166 | * Non-touchscreen sensors only use single-ended conversions. | |
167 | */ | |
168 | ||
169 | struct ser_req { | |
d93f70b2 | 170 | u8 ref_on; |
ffa458c1 | 171 | u8 command; |
d93f70b2 | 172 | u8 ref_off; |
ffa458c1 DB |
173 | u16 scratch; |
174 | __be16 sample; | |
175 | struct spi_message msg; | |
176 | struct spi_transfer xfer[6]; | |
177 | }; | |
178 | ||
7de90a8c ID |
179 | static void ads7846_enable(struct ads7846 *ts); |
180 | static void ads7846_disable(struct ads7846 *ts); | |
181 | ||
c9e617a5 ID |
182 | static int device_suspended(struct device *dev) |
183 | { | |
184 | struct ads7846 *ts = dev_get_drvdata(dev); | |
185 | return dev->power.power_state.event != PM_EVENT_ON || ts->disabled; | |
186 | } | |
187 | ||
ffa458c1 DB |
188 | static int ads7846_read12_ser(struct device *dev, unsigned command) |
189 | { | |
190 | struct spi_device *spi = to_spi_device(dev); | |
191 | struct ads7846 *ts = dev_get_drvdata(dev); | |
192 | struct ser_req *req = kzalloc(sizeof *req, SLAB_KERNEL); | |
193 | int status; | |
194 | int sample; | |
a90f7e98 | 195 | int i; |
ffa458c1 DB |
196 | |
197 | if (!req) | |
198 | return -ENOMEM; | |
199 | ||
0b7018aa | 200 | spi_message_init(&req->msg); |
8275c642 | 201 | |
ffa458c1 | 202 | /* activate reference, so it has time to settle; */ |
d93f70b2 DB |
203 | req->ref_on = REF_ON; |
204 | req->xfer[0].tx_buf = &req->ref_on; | |
ffa458c1 DB |
205 | req->xfer[0].len = 1; |
206 | req->xfer[1].rx_buf = &req->scratch; | |
207 | req->xfer[1].len = 2; | |
208 | ||
209 | /* | |
210 | * for external VREF, 0 usec (and assume it's always on); | |
211 | * for 1uF, use 800 usec; | |
212 | * no cap, 100 usec. | |
213 | */ | |
214 | req->xfer[1].delay_usecs = ts->vref_delay_usecs; | |
215 | ||
216 | /* take sample */ | |
217 | req->command = (u8) command; | |
218 | req->xfer[2].tx_buf = &req->command; | |
219 | req->xfer[2].len = 1; | |
220 | req->xfer[3].rx_buf = &req->sample; | |
221 | req->xfer[3].len = 2; | |
222 | ||
223 | /* REVISIT: take a few more samples, and compare ... */ | |
224 | ||
225 | /* turn off reference */ | |
d93f70b2 DB |
226 | req->ref_off = REF_OFF; |
227 | req->xfer[4].tx_buf = &req->ref_off; | |
ffa458c1 DB |
228 | req->xfer[4].len = 1; |
229 | req->xfer[5].rx_buf = &req->scratch; | |
230 | req->xfer[5].len = 2; | |
231 | ||
232 | CS_CHANGE(req->xfer[5]); | |
233 | ||
234 | /* group all the transfers together, so we can't interfere with | |
235 | * reading touchscreen state; disable penirq while sampling | |
236 | */ | |
8275c642 VW |
237 | for (i = 0; i < 6; i++) |
238 | spi_message_add_tail(&req->xfer[i], &req->msg); | |
ffa458c1 | 239 | |
c9e617a5 | 240 | ts->irq_disabled = 1; |
ffa458c1 DB |
241 | disable_irq(spi->irq); |
242 | status = spi_sync(spi, &req->msg); | |
c9e617a5 | 243 | ts->irq_disabled = 0; |
ffa458c1 DB |
244 | enable_irq(spi->irq); |
245 | ||
246 | if (req->msg.status) | |
247 | status = req->msg.status; | |
9084533e DB |
248 | |
249 | /* on-wire is a must-ignore bit, a BE12 value, then padding */ | |
ffa458c1 | 250 | sample = be16_to_cpu(req->sample); |
9084533e DB |
251 | sample = sample >> 3; |
252 | sample &= 0x0fff; | |
ffa458c1 | 253 | |
9084533e | 254 | kfree(req); |
ffa458c1 DB |
255 | return status ? status : sample; |
256 | } | |
257 | ||
258 | #define SHOW(name) static ssize_t \ | |
259 | name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ | |
260 | { \ | |
261 | ssize_t v = ads7846_read12_ser(dev, \ | |
262 | READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \ | |
263 | if (v < 0) \ | |
264 | return v; \ | |
265 | return sprintf(buf, "%u\n", (unsigned) v); \ | |
266 | } \ | |
267 | static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); | |
268 | ||
269 | SHOW(temp0) | |
270 | SHOW(temp1) | |
271 | SHOW(vaux) | |
272 | SHOW(vbatt) | |
273 | ||
438f2a74 ID |
274 | static int is_pen_down(struct device *dev) |
275 | { | |
276 | struct ads7846 *ts = dev_get_drvdata(dev); | |
277 | ||
278 | return ts->pendown; | |
279 | } | |
280 | ||
281 | static ssize_t ads7846_pen_down_show(struct device *dev, | |
282 | struct device_attribute *attr, char *buf) | |
283 | { | |
284 | return sprintf(buf, "%u\n", is_pen_down(dev)); | |
285 | } | |
286 | ||
287 | static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); | |
288 | ||
7de90a8c ID |
289 | static ssize_t ads7846_disable_show(struct device *dev, |
290 | struct device_attribute *attr, char *buf) | |
291 | { | |
292 | struct ads7846 *ts = dev_get_drvdata(dev); | |
293 | ||
294 | return sprintf(buf, "%u\n", ts->disabled); | |
295 | } | |
296 | ||
297 | static ssize_t ads7846_disable_store(struct device *dev, | |
298 | struct device_attribute *attr, | |
299 | const char *buf, size_t count) | |
300 | { | |
301 | struct ads7846 *ts = dev_get_drvdata(dev); | |
302 | char *endp; | |
303 | int i; | |
304 | ||
305 | i = simple_strtoul(buf, &endp, 10); | |
306 | spin_lock_irq(&ts->lock); | |
307 | ||
308 | if (i) | |
309 | ads7846_disable(ts); | |
310 | else | |
311 | ads7846_enable(ts); | |
312 | ||
313 | spin_unlock_irq(&ts->lock); | |
314 | ||
315 | return count; | |
316 | } | |
317 | ||
318 | static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); | |
319 | ||
ffa458c1 DB |
320 | /*--------------------------------------------------------------------------*/ |
321 | ||
322 | /* | |
323 | * PENIRQ only kicks the timer. The timer only reissues the SPI transfer, | |
324 | * to retrieve touchscreen status. | |
325 | * | |
326 | * The SPI transfer completion callback does the real work. It reports | |
327 | * touchscreen events and reactivates the timer (or IRQ) as appropriate. | |
328 | */ | |
329 | ||
330 | static void ads7846_rx(void *ads) | |
331 | { | |
a90f7e98 DT |
332 | struct ads7846 *ts = ads; |
333 | struct input_dev *input_dev = ts->input; | |
334 | unsigned Rt; | |
335 | unsigned sync = 0; | |
336 | u16 x, y, z1, z2; | |
337 | unsigned long flags; | |
ffa458c1 | 338 | |
9084533e DB |
339 | /* adjust: on-wire is a must-ignore bit, a BE12 value, then padding; |
340 | * built from two 8 bit values written msb-first. | |
ffa458c1 | 341 | */ |
9084533e DB |
342 | x = (be16_to_cpu(ts->tc.x) >> 3) & 0x0fff; |
343 | y = (be16_to_cpu(ts->tc.y) >> 3) & 0x0fff; | |
344 | z1 = (be16_to_cpu(ts->tc.z1) >> 3) & 0x0fff; | |
345 | z2 = (be16_to_cpu(ts->tc.z2) >> 3) & 0x0fff; | |
ffa458c1 DB |
346 | |
347 | /* range filtering */ | |
348 | if (x == MAX_12BIT) | |
349 | x = 0; | |
350 | ||
c9e617a5 | 351 | if (likely(x && z1 && !device_suspended(&ts->spi->dev))) { |
ffa458c1 DB |
352 | /* compute touch pressure resistance using equation #2 */ |
353 | Rt = z2; | |
354 | Rt -= z1; | |
355 | Rt *= x; | |
356 | Rt *= ts->x_plate_ohms; | |
357 | Rt /= z1; | |
358 | Rt = (Rt + 2047) >> 12; | |
359 | } else | |
360 | Rt = 0; | |
361 | ||
d5b415c9 ID |
362 | /* Sample found inconsistent by debouncing or pressure is beyond |
363 | * the maximum. Don't report it to user space, repeat at least | |
364 | * once more the measurement */ | |
365 | if (ts->tc.ignore || Rt > ts->pressure_max) { | |
366 | mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD); | |
367 | return; | |
368 | } | |
369 | ||
ffa458c1 DB |
370 | /* NOTE: "pendown" is inferred from pressure; we don't rely on |
371 | * being able to check nPENIRQ status, or "friendly" trigger modes | |
372 | * (both-edges is much better than just-falling or low-level). | |
373 | * | |
374 | * REVISIT: some boards may require reading nPENIRQ; it's | |
375 | * needed on 7843. and 7845 reads pressure differently... | |
376 | * | |
377 | * REVISIT: the touchscreen might not be connected; this code | |
378 | * won't notice that, even if nPENIRQ never fires ... | |
379 | */ | |
380 | if (!ts->pendown && Rt != 0) { | |
a90f7e98 | 381 | input_report_key(input_dev, BTN_TOUCH, 1); |
ffa458c1 DB |
382 | sync = 1; |
383 | } else if (ts->pendown && Rt == 0) { | |
a90f7e98 | 384 | input_report_key(input_dev, BTN_TOUCH, 0); |
ffa458c1 DB |
385 | sync = 1; |
386 | } | |
387 | ||
388 | if (Rt) { | |
a90f7e98 DT |
389 | input_report_abs(input_dev, ABS_X, x); |
390 | input_report_abs(input_dev, ABS_Y, y); | |
ffa458c1 DB |
391 | sync = 1; |
392 | } | |
ae82d5ab ID |
393 | |
394 | if (sync) { | |
395 | input_report_abs(input_dev, ABS_PRESSURE, Rt); | |
a90f7e98 | 396 | input_sync(input_dev); |
ae82d5ab | 397 | } |
ffa458c1 DB |
398 | |
399 | #ifdef VERBOSE | |
400 | if (Rt || ts->pendown) | |
401 | pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id, | |
402 | x, y, Rt, Rt ? "" : " UP"); | |
403 | #endif | |
404 | ||
ffa458c1 DB |
405 | spin_lock_irqsave(&ts->lock, flags); |
406 | ||
407 | ts->pendown = (Rt != 0); | |
c9e617a5 | 408 | mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD); |
ffa458c1 DB |
409 | |
410 | spin_unlock_irqrestore(&ts->lock, flags); | |
411 | } | |
412 | ||
0b7018aa ID |
413 | static void ads7846_debounce(void *ads) |
414 | { | |
415 | struct ads7846 *ts = ads; | |
416 | struct spi_message *m; | |
417 | struct spi_transfer *t; | |
d5b415c9 | 418 | int val; |
0b7018aa ID |
419 | int status; |
420 | ||
421 | m = &ts->msg[ts->msg_idx]; | |
422 | t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list); | |
9084533e | 423 | val = (be16_to_cpu(*(__be16 *)t->rx_buf) >> 3) & 0x0fff; |
d5b415c9 ID |
424 | if (!ts->read_cnt || (abs(ts->last_read - val) > ts->debounce_tol)) { |
425 | /* Repeat it, if this was the first read or the read | |
426 | * wasn't consistent enough. */ | |
427 | if (ts->read_cnt < ts->debounce_max) { | |
428 | ts->last_read = val; | |
429 | ts->read_cnt++; | |
430 | } else { | |
431 | /* Maximum number of debouncing reached and still | |
432 | * not enough number of consistent readings. Abort | |
433 | * the whole sample, repeat it in the next sampling | |
434 | * period. | |
435 | */ | |
436 | ts->tc.ignore = 1; | |
437 | ts->read_cnt = 0; | |
438 | /* Last message will contain ads7846_rx() as the | |
439 | * completion function. | |
440 | */ | |
441 | m = ts->last_msg; | |
442 | } | |
443 | /* Start over collecting consistent readings. */ | |
444 | ts->read_rep = 0; | |
0b7018aa | 445 | } else { |
d5b415c9 ID |
446 | if (++ts->read_rep > ts->debounce_rep) { |
447 | /* Got a good reading for this coordinate, | |
448 | * go for the next one. */ | |
449 | ts->tc.ignore = 0; | |
450 | ts->msg_idx++; | |
451 | ts->read_cnt = 0; | |
452 | ts->read_rep = 0; | |
453 | m++; | |
454 | } else | |
455 | /* Read more values that are consistent. */ | |
456 | ts->read_cnt++; | |
0b7018aa ID |
457 | } |
458 | status = spi_async(ts->spi, m); | |
459 | if (status) | |
460 | dev_err(&ts->spi->dev, "spi_async --> %d\n", | |
461 | status); | |
462 | } | |
463 | ||
ffa458c1 DB |
464 | static void ads7846_timer(unsigned long handle) |
465 | { | |
466 | struct ads7846 *ts = (void *)handle; | |
467 | int status = 0; | |
0b7018aa | 468 | |
c9e617a5 ID |
469 | spin_lock_irq(&ts->lock); |
470 | ||
471 | if (unlikely(ts->msg_idx && !ts->pendown)) { | |
9084533e | 472 | /* measurement cycle ended */ |
c9e617a5 ID |
473 | if (!device_suspended(&ts->spi->dev)) { |
474 | ts->irq_disabled = 0; | |
475 | enable_irq(ts->spi->irq); | |
476 | } | |
477 | ts->pending = 0; | |
478 | ts->msg_idx = 0; | |
479 | } else { | |
480 | /* pen is still down, continue with the measurement */ | |
481 | ts->msg_idx = 0; | |
482 | status = spi_async(ts->spi, &ts->msg[0]); | |
483 | if (status) | |
484 | dev_err(&ts->spi->dev, "spi_async --> %d\n", status); | |
485 | } | |
486 | ||
487 | spin_unlock_irq(&ts->lock); | |
0b7018aa ID |
488 | } |
489 | ||
490 | static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs) | |
491 | { | |
492 | struct ads7846 *ts = handle; | |
493 | unsigned long flags; | |
ffa458c1 DB |
494 | |
495 | spin_lock_irqsave(&ts->lock, flags); | |
c9e617a5 | 496 | if (likely(ts->get_pendown_state())) { |
ffa458c1 | 497 | if (!ts->irq_disabled) { |
9084533e DB |
498 | /* The ARM do_simple_IRQ() dispatcher doesn't act |
499 | * like the other dispatchers: it will report IRQs | |
500 | * even after they've been disabled. We work around | |
501 | * that here. (The "generic irq" framework may help...) | |
0b7018aa | 502 | */ |
ffa458c1 DB |
503 | ts->irq_disabled = 1; |
504 | disable_irq(ts->spi->irq); | |
0b7018aa ID |
505 | ts->pending = 1; |
506 | mod_timer(&ts->timer, jiffies); | |
507 | } | |
ffa458c1 DB |
508 | } |
509 | spin_unlock_irqrestore(&ts->lock, flags); | |
7de90a8c ID |
510 | |
511 | return IRQ_HANDLED; | |
ffa458c1 DB |
512 | } |
513 | ||
514 | /*--------------------------------------------------------------------------*/ | |
515 | ||
7de90a8c ID |
516 | /* Must be called with ts->lock held */ |
517 | static void ads7846_disable(struct ads7846 *ts) | |
ffa458c1 | 518 | { |
7de90a8c ID |
519 | if (ts->disabled) |
520 | return; | |
ffa458c1 | 521 | |
c9e617a5 ID |
522 | ts->disabled = 1; |
523 | ||
ffa458c1 | 524 | /* are we waiting for IRQ, or polling? */ |
c9e617a5 ID |
525 | if (!ts->pending) { |
526 | ts->irq_disabled = 1; | |
527 | disable_irq(ts->spi->irq); | |
ffa458c1 | 528 | } else { |
c9e617a5 ID |
529 | /* the timer will run at least once more, and |
530 | * leave everything in a clean state, IRQ disabled | |
ffa458c1 | 531 | */ |
c9e617a5 | 532 | while (ts->pending) { |
7de90a8c | 533 | spin_unlock_irq(&ts->lock); |
c4febb94 | 534 | msleep(1); |
7de90a8c | 535 | spin_lock_irq(&ts->lock); |
ffa458c1 DB |
536 | } |
537 | } | |
538 | ||
539 | /* we know the chip's in lowpower mode since we always | |
540 | * leave it that way after every request | |
541 | */ | |
542 | ||
7de90a8c ID |
543 | } |
544 | ||
545 | /* Must be called with ts->lock held */ | |
546 | static void ads7846_enable(struct ads7846 *ts) | |
547 | { | |
548 | if (!ts->disabled) | |
549 | return; | |
550 | ||
551 | ts->disabled = 0; | |
552 | ts->irq_disabled = 0; | |
553 | enable_irq(ts->spi->irq); | |
554 | } | |
555 | ||
556 | static int ads7846_suspend(struct spi_device *spi, pm_message_t message) | |
557 | { | |
558 | struct ads7846 *ts = dev_get_drvdata(&spi->dev); | |
559 | ||
560 | spin_lock_irq(&ts->lock); | |
561 | ||
562 | spi->dev.power.power_state = message; | |
563 | ads7846_disable(ts); | |
564 | ||
565 | spin_unlock_irq(&ts->lock); | |
566 | ||
ffa458c1 | 567 | return 0; |
7de90a8c | 568 | |
ffa458c1 DB |
569 | } |
570 | ||
2e5a7bd9 | 571 | static int ads7846_resume(struct spi_device *spi) |
ffa458c1 | 572 | { |
2e5a7bd9 | 573 | struct ads7846 *ts = dev_get_drvdata(&spi->dev); |
ffa458c1 | 574 | |
7de90a8c ID |
575 | spin_lock_irq(&ts->lock); |
576 | ||
2e5a7bd9 | 577 | spi->dev.power.power_state = PMSG_ON; |
7de90a8c ID |
578 | ads7846_enable(ts); |
579 | ||
580 | spin_unlock_irq(&ts->lock); | |
581 | ||
ffa458c1 DB |
582 | return 0; |
583 | } | |
584 | ||
2e5a7bd9 | 585 | static int __devinit ads7846_probe(struct spi_device *spi) |
ffa458c1 | 586 | { |
ffa458c1 | 587 | struct ads7846 *ts; |
a90f7e98 | 588 | struct input_dev *input_dev; |
2e5a7bd9 | 589 | struct ads7846_platform_data *pdata = spi->dev.platform_data; |
0b7018aa | 590 | struct spi_message *m; |
ffa458c1 | 591 | struct spi_transfer *x; |
a90f7e98 | 592 | int err; |
ffa458c1 DB |
593 | |
594 | if (!spi->irq) { | |
2e5a7bd9 | 595 | dev_dbg(&spi->dev, "no IRQ?\n"); |
ffa458c1 DB |
596 | return -ENODEV; |
597 | } | |
598 | ||
599 | if (!pdata) { | |
2e5a7bd9 | 600 | dev_dbg(&spi->dev, "no platform data?\n"); |
ffa458c1 DB |
601 | return -ENODEV; |
602 | } | |
603 | ||
604 | /* don't exceed max specified sample rate */ | |
d93f70b2 | 605 | if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { |
2e5a7bd9 | 606 | dev_dbg(&spi->dev, "f(sample) %d KHz?\n", |
d93f70b2 | 607 | (spi->max_speed_hz/SAMPLE_BITS)/1000); |
ffa458c1 DB |
608 | return -EINVAL; |
609 | } | |
610 | ||
9084533e DB |
611 | /* REVISIT when the irq can be triggered active-low, or if for some |
612 | * reason the touchscreen isn't hooked up, we don't need to access | |
613 | * the pendown state. | |
614 | */ | |
c9e617a5 ID |
615 | if (pdata->get_pendown_state == NULL) { |
616 | dev_dbg(&spi->dev, "no get_pendown_state function?\n"); | |
617 | return -EINVAL; | |
618 | } | |
619 | ||
9084533e DB |
620 | /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except |
621 | * that even if the hardware can do that, the SPI controller driver | |
622 | * may not. So we stick to very-portable 8 bit words, both RX and TX. | |
ffa458c1 | 623 | */ |
9084533e | 624 | spi->bits_per_word = 8; |
ffa458c1 | 625 | |
a90f7e98 DT |
626 | ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); |
627 | input_dev = input_allocate_device(); | |
628 | if (!ts || !input_dev) { | |
629 | err = -ENOMEM; | |
630 | goto err_free_mem; | |
631 | } | |
ffa458c1 | 632 | |
2e5a7bd9 | 633 | dev_set_drvdata(&spi->dev, ts); |
a90f7e98 | 634 | spi->dev.power.power_state = PMSG_ON; |
ffa458c1 DB |
635 | |
636 | ts->spi = spi; | |
a90f7e98 | 637 | ts->input = input_dev; |
ffa458c1 DB |
638 | |
639 | init_timer(&ts->timer); | |
640 | ts->timer.data = (unsigned long) ts; | |
641 | ts->timer.function = ads7846_timer; | |
642 | ||
7de90a8c ID |
643 | spin_lock_init(&ts->lock); |
644 | ||
ffa458c1 DB |
645 | ts->model = pdata->model ? : 7846; |
646 | ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; | |
647 | ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; | |
d5b415c9 ID |
648 | ts->pressure_max = pdata->pressure_max ? : ~0; |
649 | if (pdata->debounce_max) { | |
650 | ts->debounce_max = pdata->debounce_max; | |
651 | ts->debounce_tol = pdata->debounce_tol; | |
652 | ts->debounce_rep = pdata->debounce_rep; | |
653 | if (ts->debounce_rep > ts->debounce_max + 1) | |
654 | ts->debounce_rep = ts->debounce_max - 1; | |
655 | } else | |
656 | ts->debounce_tol = ~0; | |
c9e617a5 | 657 | ts->get_pendown_state = pdata->get_pendown_state; |
ffa458c1 | 658 | |
a90f7e98 | 659 | snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id); |
ffa458c1 | 660 | |
a90f7e98 DT |
661 | input_dev->name = "ADS784x Touchscreen"; |
662 | input_dev->phys = ts->phys; | |
663 | input_dev->cdev.dev = &spi->dev; | |
ffa458c1 | 664 | |
a90f7e98 DT |
665 | input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS); |
666 | input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH); | |
667 | input_set_abs_params(input_dev, ABS_X, | |
ffa458c1 DB |
668 | pdata->x_min ? : 0, |
669 | pdata->x_max ? : MAX_12BIT, | |
670 | 0, 0); | |
a90f7e98 | 671 | input_set_abs_params(input_dev, ABS_Y, |
ffa458c1 DB |
672 | pdata->y_min ? : 0, |
673 | pdata->y_max ? : MAX_12BIT, | |
674 | 0, 0); | |
a90f7e98 | 675 | input_set_abs_params(input_dev, ABS_PRESSURE, |
ffa458c1 DB |
676 | pdata->pressure_min, pdata->pressure_max, 0, 0); |
677 | ||
ffa458c1 DB |
678 | /* set up the transfers to read touchscreen state; this assumes we |
679 | * use formula #2 for pressure, not #3. | |
680 | */ | |
0b7018aa | 681 | m = &ts->msg[0]; |
ffa458c1 DB |
682 | x = ts->xfer; |
683 | ||
0b7018aa ID |
684 | spi_message_init(m); |
685 | ||
ffa458c1 | 686 | /* y- still on; turn on only y+ (and ADC) */ |
d93f70b2 DB |
687 | ts->read_y = READ_Y; |
688 | x->tx_buf = &ts->read_y; | |
ffa458c1 | 689 | x->len = 1; |
0b7018aa | 690 | spi_message_add_tail(x, m); |
d93f70b2 | 691 | |
ffa458c1 DB |
692 | x++; |
693 | x->rx_buf = &ts->tc.y; | |
694 | x->len = 2; | |
0b7018aa ID |
695 | spi_message_add_tail(x, m); |
696 | ||
697 | m->complete = ads7846_debounce; | |
698 | m->context = ts; | |
699 | ||
700 | m++; | |
701 | spi_message_init(m); | |
702 | ||
703 | /* turn y- off, x+ on, then leave in lowpower */ | |
704 | x++; | |
705 | ts->read_x = READ_X; | |
706 | x->tx_buf = &ts->read_x; | |
707 | x->len = 1; | |
708 | spi_message_add_tail(x, m); | |
709 | ||
710 | x++; | |
711 | x->rx_buf = &ts->tc.x; | |
712 | x->len = 2; | |
713 | spi_message_add_tail(x, m); | |
714 | ||
715 | m->complete = ads7846_debounce; | |
716 | m->context = ts; | |
ffa458c1 DB |
717 | |
718 | /* turn y+ off, x- on; we'll use formula #2 */ | |
719 | if (ts->model == 7846) { | |
0b7018aa ID |
720 | m++; |
721 | spi_message_init(m); | |
722 | ||
d93f70b2 DB |
723 | x++; |
724 | ts->read_z1 = READ_Z1; | |
725 | x->tx_buf = &ts->read_z1; | |
ffa458c1 | 726 | x->len = 1; |
0b7018aa | 727 | spi_message_add_tail(x, m); |
d93f70b2 | 728 | |
ffa458c1 DB |
729 | x++; |
730 | x->rx_buf = &ts->tc.z1; | |
731 | x->len = 2; | |
0b7018aa ID |
732 | spi_message_add_tail(x, m); |
733 | ||
734 | m->complete = ads7846_debounce; | |
735 | m->context = ts; | |
736 | ||
737 | m++; | |
738 | spi_message_init(m); | |
ffa458c1 | 739 | |
d93f70b2 DB |
740 | x++; |
741 | ts->read_z2 = READ_Z2; | |
742 | x->tx_buf = &ts->read_z2; | |
ffa458c1 | 743 | x->len = 1; |
0b7018aa | 744 | spi_message_add_tail(x, m); |
d93f70b2 | 745 | |
ffa458c1 DB |
746 | x++; |
747 | x->rx_buf = &ts->tc.z2; | |
748 | x->len = 2; | |
0b7018aa | 749 | spi_message_add_tail(x, m); |
ffa458c1 | 750 | |
0b7018aa ID |
751 | m->complete = ads7846_debounce; |
752 | m->context = ts; | |
753 | } | |
53a0ef89 ID |
754 | |
755 | /* power down */ | |
0b7018aa ID |
756 | m++; |
757 | spi_message_init(m); | |
758 | ||
53a0ef89 ID |
759 | x++; |
760 | ts->pwrdown = PWRDOWN; | |
761 | x->tx_buf = &ts->pwrdown; | |
762 | x->len = 1; | |
0b7018aa | 763 | spi_message_add_tail(x, m); |
53a0ef89 ID |
764 | |
765 | x++; | |
766 | x->rx_buf = &ts->dummy; | |
767 | x->len = 2; | |
d93f70b2 | 768 | CS_CHANGE(*x); |
0b7018aa | 769 | spi_message_add_tail(x, m); |
ffa458c1 | 770 | |
0b7018aa ID |
771 | m->complete = ads7846_rx; |
772 | m->context = ts; | |
ffa458c1 | 773 | |
d5b415c9 ID |
774 | ts->last_msg = m; |
775 | ||
dace1453 | 776 | if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING, |
9084533e | 777 | spi->dev.driver->name, ts)) { |
2e5a7bd9 | 778 | dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); |
a90f7e98 DT |
779 | err = -EBUSY; |
780 | goto err_free_mem; | |
ffa458c1 | 781 | } |
ffa458c1 | 782 | |
2e5a7bd9 | 783 | dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); |
ffa458c1 DB |
784 | |
785 | /* take a first sample, leaving nPENIRQ active; avoid | |
786 | * the touchscreen, in case it's not connected. | |
787 | */ | |
2e5a7bd9 | 788 | (void) ads7846_read12_ser(&spi->dev, |
ffa458c1 DB |
789 | READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON); |
790 | ||
791 | /* ads7843/7845 don't have temperature sensors, and | |
792 | * use the other sensors a bit differently too | |
793 | */ | |
794 | if (ts->model == 7846) { | |
2e5a7bd9 DB |
795 | device_create_file(&spi->dev, &dev_attr_temp0); |
796 | device_create_file(&spi->dev, &dev_attr_temp1); | |
ffa458c1 DB |
797 | } |
798 | if (ts->model != 7845) | |
2e5a7bd9 DB |
799 | device_create_file(&spi->dev, &dev_attr_vbatt); |
800 | device_create_file(&spi->dev, &dev_attr_vaux); | |
ffa458c1 | 801 | |
438f2a74 ID |
802 | device_create_file(&spi->dev, &dev_attr_pen_down); |
803 | ||
7de90a8c ID |
804 | device_create_file(&spi->dev, &dev_attr_disable); |
805 | ||
a90f7e98 DT |
806 | err = input_register_device(input_dev); |
807 | if (err) | |
7de90a8c | 808 | goto err_remove_attr; |
a90f7e98 | 809 | |
ffa458c1 | 810 | return 0; |
a90f7e98 | 811 | |
7de90a8c ID |
812 | err_remove_attr: |
813 | device_remove_file(&spi->dev, &dev_attr_disable); | |
814 | device_remove_file(&spi->dev, &dev_attr_pen_down); | |
815 | if (ts->model == 7846) { | |
816 | device_remove_file(&spi->dev, &dev_attr_temp1); | |
817 | device_remove_file(&spi->dev, &dev_attr_temp0); | |
818 | } | |
819 | if (ts->model != 7845) | |
820 | device_remove_file(&spi->dev, &dev_attr_vbatt); | |
821 | device_remove_file(&spi->dev, &dev_attr_vaux); | |
822 | ||
a90f7e98 DT |
823 | free_irq(spi->irq, ts); |
824 | err_free_mem: | |
825 | input_free_device(input_dev); | |
826 | kfree(ts); | |
827 | return err; | |
ffa458c1 DB |
828 | } |
829 | ||
2e5a7bd9 | 830 | static int __devexit ads7846_remove(struct spi_device *spi) |
ffa458c1 | 831 | { |
2e5a7bd9 | 832 | struct ads7846 *ts = dev_get_drvdata(&spi->dev); |
ffa458c1 | 833 | |
7de90a8c ID |
834 | input_unregister_device(ts->input); |
835 | ||
2e5a7bd9 | 836 | ads7846_suspend(spi, PMSG_SUSPEND); |
ffa458c1 | 837 | |
7de90a8c | 838 | device_remove_file(&spi->dev, &dev_attr_disable); |
438f2a74 | 839 | device_remove_file(&spi->dev, &dev_attr_pen_down); |
ffa458c1 | 840 | if (ts->model == 7846) { |
2e5a7bd9 | 841 | device_remove_file(&spi->dev, &dev_attr_temp1); |
7de90a8c | 842 | device_remove_file(&spi->dev, &dev_attr_temp0); |
ffa458c1 DB |
843 | } |
844 | if (ts->model != 7845) | |
2e5a7bd9 DB |
845 | device_remove_file(&spi->dev, &dev_attr_vbatt); |
846 | device_remove_file(&spi->dev, &dev_attr_vaux); | |
ffa458c1 | 847 | |
7de90a8c | 848 | free_irq(ts->spi->irq, ts); |
c9e617a5 ID |
849 | /* suspend left the IRQ disabled */ |
850 | enable_irq(ts->spi->irq); | |
7de90a8c | 851 | |
ffa458c1 DB |
852 | kfree(ts); |
853 | ||
2e5a7bd9 | 854 | dev_dbg(&spi->dev, "unregistered touchscreen\n"); |
ffa458c1 DB |
855 | return 0; |
856 | } | |
857 | ||
2e5a7bd9 DB |
858 | static struct spi_driver ads7846_driver = { |
859 | .driver = { | |
860 | .name = "ads7846", | |
861 | .bus = &spi_bus_type, | |
862 | .owner = THIS_MODULE, | |
863 | }, | |
ffa458c1 | 864 | .probe = ads7846_probe, |
2e5a7bd9 | 865 | .remove = __devexit_p(ads7846_remove), |
ffa458c1 DB |
866 | .suspend = ads7846_suspend, |
867 | .resume = ads7846_resume, | |
868 | }; | |
869 | ||
870 | static int __init ads7846_init(void) | |
871 | { | |
872 | /* grr, board-specific init should stay out of drivers!! */ | |
873 | ||
874 | #ifdef CONFIG_ARCH_OMAP | |
875 | if (machine_is_omap_osk()) { | |
876 | /* GPIO4 = PENIRQ; GPIO6 = BUSY */ | |
877 | omap_request_gpio(4); | |
878 | omap_set_gpio_direction(4, 1); | |
879 | omap_request_gpio(6); | |
880 | omap_set_gpio_direction(6, 1); | |
881 | } | |
882 | // also TI 1510 Innovator, bitbanging through FPGA | |
883 | // also Nokia 770 | |
884 | // also Palm Tungsten T2 | |
885 | #endif | |
886 | ||
887 | // PXA: | |
888 | // also Dell Axim X50 | |
889 | // also HP iPaq H191x/H192x/H415x/H435x | |
2e5a7bd9 | 890 | // also Intel Lubbock (additional to UCB1400; as temperature sensor) |
ffa458c1 DB |
891 | // also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky) |
892 | ||
2e5a7bd9 DB |
893 | // Atmel at91sam9261-EK uses ads7843 |
894 | ||
ffa458c1 DB |
895 | // also various AMD Au1x00 devel boards |
896 | ||
2e5a7bd9 | 897 | return spi_register_driver(&ads7846_driver); |
ffa458c1 DB |
898 | } |
899 | module_init(ads7846_init); | |
900 | ||
901 | static void __exit ads7846_exit(void) | |
902 | { | |
2e5a7bd9 | 903 | spi_unregister_driver(&ads7846_driver); |
ffa458c1 DB |
904 | |
905 | #ifdef CONFIG_ARCH_OMAP | |
906 | if (machine_is_omap_osk()) { | |
907 | omap_free_gpio(4); | |
908 | omap_free_gpio(6); | |
909 | } | |
910 | #endif | |
911 | ||
912 | } | |
913 | module_exit(ads7846_exit); | |
914 | ||
915 | MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); | |
916 | MODULE_LICENSE("GPL"); |