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1 | /* | |
2 | * ADS7846 based touchscreen and sensor driver | |
3 | * | |
4 | * Copyright (c) 2005 David Brownell | |
5 | * Copyright (c) 2006 Nokia Corporation | |
6 | * Various changes: Imre Deak <imre.deak@nokia.com> | |
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/types.h> | |
21 | #include <linux/hwmon.h> | |
22 | #include <linux/err.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/delay.h> | |
25 | #include <linux/input.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/pm.h> | |
29 | #include <linux/of.h> | |
30 | #include <linux/of_gpio.h> | |
31 | #include <linux/of_device.h> | |
32 | #include <linux/gpio.h> | |
33 | #include <linux/spi/spi.h> | |
34 | #include <linux/spi/ads7846.h> | |
35 | #include <linux/regulator/consumer.h> | |
36 | #include <linux/module.h> | |
37 | #include <asm/irq.h> | |
38 | ||
39 | /* | |
40 | * This code has been heavily tested on a Nokia 770, and lightly | |
41 | * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). | |
42 | * TSC2046 is just newer ads7846 silicon. | |
43 | * Support for ads7843 tested on Atmel at91sam926x-EK. | |
44 | * Support for ads7845 has only been stubbed in. | |
45 | * Support for Analog Devices AD7873 and AD7843 tested. | |
46 | * | |
47 | * IRQ handling needs a workaround because of a shortcoming in handling | |
48 | * edge triggered IRQs on some platforms like the OMAP1/2. These | |
49 | * platforms don't handle the ARM lazy IRQ disabling properly, thus we | |
50 | * have to maintain our own SW IRQ disabled status. This should be | |
51 | * removed as soon as the affected platform's IRQ handling is fixed. | |
52 | * | |
53 | * App note sbaa036 talks in more detail about accurate sampling... | |
54 | * that ought to help in situations like LCDs inducing noise (which | |
55 | * can also be helped by using synch signals) and more generally. | |
56 | * This driver tries to utilize the measures described in the app | |
57 | * note. The strength of filtering can be set in the board-* specific | |
58 | * files. | |
59 | */ | |
60 | ||
61 | #define TS_POLL_DELAY 1 /* ms delay before the first sample */ | |
62 | #define TS_POLL_PERIOD 5 /* ms delay between samples */ | |
63 | ||
64 | /* this driver doesn't aim at the peak continuous sample rate */ | |
65 | #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) | |
66 | ||
67 | struct ts_event { | |
68 | /* | |
69 | * For portability, we can't read 12 bit values using SPI (which | |
70 | * would make the controller deliver them as native byte order u16 | |
71 | * with msbs zeroed). Instead, we read them as two 8-bit values, | |
72 | * *** WHICH NEED BYTESWAPPING *** and range adjustment. | |
73 | */ | |
74 | u16 x; | |
75 | u16 y; | |
76 | u16 z1, z2; | |
77 | bool ignore; | |
78 | u8 x_buf[3]; | |
79 | u8 y_buf[3]; | |
80 | }; | |
81 | ||
82 | /* | |
83 | * We allocate this separately to avoid cache line sharing issues when | |
84 | * driver is used with DMA-based SPI controllers (like atmel_spi) on | |
85 | * systems where main memory is not DMA-coherent (most non-x86 boards). | |
86 | */ | |
87 | struct ads7846_packet { | |
88 | u8 read_x, read_y, read_z1, read_z2, pwrdown; | |
89 | u16 dummy; /* for the pwrdown read */ | |
90 | struct ts_event tc; | |
91 | /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ | |
92 | u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; | |
93 | }; | |
94 | ||
95 | struct ads7846 { | |
96 | struct input_dev *input; | |
97 | char phys[32]; | |
98 | char name[32]; | |
99 | ||
100 | struct spi_device *spi; | |
101 | struct regulator *reg; | |
102 | ||
103 | #if IS_ENABLED(CONFIG_HWMON) | |
104 | struct device *hwmon; | |
105 | #endif | |
106 | ||
107 | u16 model; | |
108 | u16 vref_mv; | |
109 | u16 vref_delay_usecs; | |
110 | u16 x_plate_ohms; | |
111 | u16 pressure_max; | |
112 | ||
113 | bool swap_xy; | |
114 | bool use_internal; | |
115 | ||
116 | struct ads7846_packet *packet; | |
117 | ||
118 | struct spi_transfer xfer[18]; | |
119 | struct spi_message msg[5]; | |
120 | int msg_count; | |
121 | wait_queue_head_t wait; | |
122 | ||
123 | bool pendown; | |
124 | ||
125 | int read_cnt; | |
126 | int read_rep; | |
127 | int last_read; | |
128 | ||
129 | u16 debounce_max; | |
130 | u16 debounce_tol; | |
131 | u16 debounce_rep; | |
132 | ||
133 | u16 penirq_recheck_delay_usecs; | |
134 | ||
135 | struct mutex lock; | |
136 | bool stopped; /* P: lock */ | |
137 | bool disabled; /* P: lock */ | |
138 | bool suspended; /* P: lock */ | |
139 | ||
140 | int (*filter)(void *data, int data_idx, int *val); | |
141 | void *filter_data; | |
142 | void (*filter_cleanup)(void *data); | |
143 | int (*get_pendown_state)(void); | |
144 | int gpio_pendown; | |
145 | ||
146 | void (*wait_for_sync)(void); | |
147 | }; | |
148 | ||
149 | /* leave chip selected when we're done, for quicker re-select? */ | |
150 | #if 0 | |
151 | #define CS_CHANGE(xfer) ((xfer).cs_change = 1) | |
152 | #else | |
153 | #define CS_CHANGE(xfer) ((xfer).cs_change = 0) | |
154 | #endif | |
155 | ||
156 | /*--------------------------------------------------------------------------*/ | |
157 | ||
158 | /* The ADS7846 has touchscreen and other sensors. | |
159 | * Earlier ads784x chips are somewhat compatible. | |
160 | */ | |
161 | #define ADS_START (1 << 7) | |
162 | #define ADS_A2A1A0_d_y (1 << 4) /* differential */ | |
163 | #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ | |
164 | #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ | |
165 | #define ADS_A2A1A0_d_x (5 << 4) /* differential */ | |
166 | #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ | |
167 | #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ | |
168 | #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ | |
169 | #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ | |
170 | #define ADS_8_BIT (1 << 3) | |
171 | #define ADS_12_BIT (0 << 3) | |
172 | #define ADS_SER (1 << 2) /* non-differential */ | |
173 | #define ADS_DFR (0 << 2) /* differential */ | |
174 | #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ | |
175 | #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ | |
176 | #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ | |
177 | #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ | |
178 | ||
179 | #define MAX_12BIT ((1<<12)-1) | |
180 | ||
181 | /* leave ADC powered up (disables penirq) between differential samples */ | |
182 | #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ | |
183 | | ADS_12_BIT | ADS_DFR | \ | |
184 | (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) | |
185 | ||
186 | #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) | |
187 | #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) | |
188 | #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) | |
189 | ||
190 | #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) | |
191 | #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ | |
192 | ||
193 | /* single-ended samples need to first power up reference voltage; | |
194 | * we leave both ADC and VREF powered | |
195 | */ | |
196 | #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ | |
197 | | ADS_12_BIT | ADS_SER) | |
198 | ||
199 | #define REF_ON (READ_12BIT_DFR(x, 1, 1)) | |
200 | #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) | |
201 | ||
202 | /* Must be called with ts->lock held */ | |
203 | static void ads7846_stop(struct ads7846 *ts) | |
204 | { | |
205 | if (!ts->disabled && !ts->suspended) { | |
206 | /* Signal IRQ thread to stop polling and disable the handler. */ | |
207 | ts->stopped = true; | |
208 | mb(); | |
209 | wake_up(&ts->wait); | |
210 | disable_irq(ts->spi->irq); | |
211 | } | |
212 | } | |
213 | ||
214 | /* Must be called with ts->lock held */ | |
215 | static void ads7846_restart(struct ads7846 *ts) | |
216 | { | |
217 | if (!ts->disabled && !ts->suspended) { | |
218 | /* Tell IRQ thread that it may poll the device. */ | |
219 | ts->stopped = false; | |
220 | mb(); | |
221 | enable_irq(ts->spi->irq); | |
222 | } | |
223 | } | |
224 | ||
225 | /* Must be called with ts->lock held */ | |
226 | static void __ads7846_disable(struct ads7846 *ts) | |
227 | { | |
228 | ads7846_stop(ts); | |
229 | regulator_disable(ts->reg); | |
230 | ||
231 | /* | |
232 | * We know the chip's in low power mode since we always | |
233 | * leave it that way after every request | |
234 | */ | |
235 | } | |
236 | ||
237 | /* Must be called with ts->lock held */ | |
238 | static void __ads7846_enable(struct ads7846 *ts) | |
239 | { | |
240 | int error; | |
241 | ||
242 | error = regulator_enable(ts->reg); | |
243 | if (error != 0) | |
244 | dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); | |
245 | ||
246 | ads7846_restart(ts); | |
247 | } | |
248 | ||
249 | static void ads7846_disable(struct ads7846 *ts) | |
250 | { | |
251 | mutex_lock(&ts->lock); | |
252 | ||
253 | if (!ts->disabled) { | |
254 | ||
255 | if (!ts->suspended) | |
256 | __ads7846_disable(ts); | |
257 | ||
258 | ts->disabled = true; | |
259 | } | |
260 | ||
261 | mutex_unlock(&ts->lock); | |
262 | } | |
263 | ||
264 | static void ads7846_enable(struct ads7846 *ts) | |
265 | { | |
266 | mutex_lock(&ts->lock); | |
267 | ||
268 | if (ts->disabled) { | |
269 | ||
270 | ts->disabled = false; | |
271 | ||
272 | if (!ts->suspended) | |
273 | __ads7846_enable(ts); | |
274 | } | |
275 | ||
276 | mutex_unlock(&ts->lock); | |
277 | } | |
278 | ||
279 | /*--------------------------------------------------------------------------*/ | |
280 | ||
281 | /* | |
282 | * Non-touchscreen sensors only use single-ended conversions. | |
283 | * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; | |
284 | * ads7846 lets that pin be unconnected, to use internal vREF. | |
285 | */ | |
286 | ||
287 | struct ser_req { | |
288 | u8 ref_on; | |
289 | u8 command; | |
290 | u8 ref_off; | |
291 | u16 scratch; | |
292 | struct spi_message msg; | |
293 | struct spi_transfer xfer[6]; | |
294 | /* | |
295 | * DMA (thus cache coherency maintenance) requires the | |
296 | * transfer buffers to live in their own cache lines. | |
297 | */ | |
298 | __be16 sample ____cacheline_aligned; | |
299 | }; | |
300 | ||
301 | struct ads7845_ser_req { | |
302 | u8 command[3]; | |
303 | struct spi_message msg; | |
304 | struct spi_transfer xfer[2]; | |
305 | /* | |
306 | * DMA (thus cache coherency maintenance) requires the | |
307 | * transfer buffers to live in their own cache lines. | |
308 | */ | |
309 | u8 sample[3] ____cacheline_aligned; | |
310 | }; | |
311 | ||
312 | static int ads7846_read12_ser(struct device *dev, unsigned command) | |
313 | { | |
314 | struct spi_device *spi = to_spi_device(dev); | |
315 | struct ads7846 *ts = dev_get_drvdata(dev); | |
316 | struct ser_req *req; | |
317 | int status; | |
318 | ||
319 | req = kzalloc(sizeof *req, GFP_KERNEL); | |
320 | if (!req) | |
321 | return -ENOMEM; | |
322 | ||
323 | spi_message_init(&req->msg); | |
324 | ||
325 | /* maybe turn on internal vREF, and let it settle */ | |
326 | if (ts->use_internal) { | |
327 | req->ref_on = REF_ON; | |
328 | req->xfer[0].tx_buf = &req->ref_on; | |
329 | req->xfer[0].len = 1; | |
330 | spi_message_add_tail(&req->xfer[0], &req->msg); | |
331 | ||
332 | req->xfer[1].rx_buf = &req->scratch; | |
333 | req->xfer[1].len = 2; | |
334 | ||
335 | /* for 1uF, settle for 800 usec; no cap, 100 usec. */ | |
336 | req->xfer[1].delay_usecs = ts->vref_delay_usecs; | |
337 | spi_message_add_tail(&req->xfer[1], &req->msg); | |
338 | ||
339 | /* Enable reference voltage */ | |
340 | command |= ADS_PD10_REF_ON; | |
341 | } | |
342 | ||
343 | /* Enable ADC in every case */ | |
344 | command |= ADS_PD10_ADC_ON; | |
345 | ||
346 | /* take sample */ | |
347 | req->command = (u8) command; | |
348 | req->xfer[2].tx_buf = &req->command; | |
349 | req->xfer[2].len = 1; | |
350 | spi_message_add_tail(&req->xfer[2], &req->msg); | |
351 | ||
352 | req->xfer[3].rx_buf = &req->sample; | |
353 | req->xfer[3].len = 2; | |
354 | spi_message_add_tail(&req->xfer[3], &req->msg); | |
355 | ||
356 | /* REVISIT: take a few more samples, and compare ... */ | |
357 | ||
358 | /* converter in low power mode & enable PENIRQ */ | |
359 | req->ref_off = PWRDOWN; | |
360 | req->xfer[4].tx_buf = &req->ref_off; | |
361 | req->xfer[4].len = 1; | |
362 | spi_message_add_tail(&req->xfer[4], &req->msg); | |
363 | ||
364 | req->xfer[5].rx_buf = &req->scratch; | |
365 | req->xfer[5].len = 2; | |
366 | CS_CHANGE(req->xfer[5]); | |
367 | spi_message_add_tail(&req->xfer[5], &req->msg); | |
368 | ||
369 | mutex_lock(&ts->lock); | |
370 | ads7846_stop(ts); | |
371 | status = spi_sync(spi, &req->msg); | |
372 | ads7846_restart(ts); | |
373 | mutex_unlock(&ts->lock); | |
374 | ||
375 | if (status == 0) { | |
376 | /* on-wire is a must-ignore bit, a BE12 value, then padding */ | |
377 | status = be16_to_cpu(req->sample); | |
378 | status = status >> 3; | |
379 | status &= 0x0fff; | |
380 | } | |
381 | ||
382 | kfree(req); | |
383 | return status; | |
384 | } | |
385 | ||
386 | static int ads7845_read12_ser(struct device *dev, unsigned command) | |
387 | { | |
388 | struct spi_device *spi = to_spi_device(dev); | |
389 | struct ads7846 *ts = dev_get_drvdata(dev); | |
390 | struct ads7845_ser_req *req; | |
391 | int status; | |
392 | ||
393 | req = kzalloc(sizeof *req, GFP_KERNEL); | |
394 | if (!req) | |
395 | return -ENOMEM; | |
396 | ||
397 | spi_message_init(&req->msg); | |
398 | ||
399 | req->command[0] = (u8) command; | |
400 | req->xfer[0].tx_buf = req->command; | |
401 | req->xfer[0].rx_buf = req->sample; | |
402 | req->xfer[0].len = 3; | |
403 | spi_message_add_tail(&req->xfer[0], &req->msg); | |
404 | ||
405 | mutex_lock(&ts->lock); | |
406 | ads7846_stop(ts); | |
407 | status = spi_sync(spi, &req->msg); | |
408 | ads7846_restart(ts); | |
409 | mutex_unlock(&ts->lock); | |
410 | ||
411 | if (status == 0) { | |
412 | /* BE12 value, then padding */ | |
413 | status = be16_to_cpu(*((u16 *)&req->sample[1])); | |
414 | status = status >> 3; | |
415 | status &= 0x0fff; | |
416 | } | |
417 | ||
418 | kfree(req); | |
419 | return status; | |
420 | } | |
421 | ||
422 | #if IS_ENABLED(CONFIG_HWMON) | |
423 | ||
424 | #define SHOW(name, var, adjust) static ssize_t \ | |
425 | name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ | |
426 | { \ | |
427 | struct ads7846 *ts = dev_get_drvdata(dev); \ | |
428 | ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ | |
429 | READ_12BIT_SER(var)); \ | |
430 | if (v < 0) \ | |
431 | return v; \ | |
432 | return sprintf(buf, "%u\n", adjust(ts, v)); \ | |
433 | } \ | |
434 | static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); | |
435 | ||
436 | ||
437 | /* Sysfs conventions report temperatures in millidegrees Celsius. | |
438 | * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high | |
439 | * accuracy scheme without calibration data. For now we won't try either; | |
440 | * userspace sees raw sensor values, and must scale/calibrate appropriately. | |
441 | */ | |
442 | static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) | |
443 | { | |
444 | return v; | |
445 | } | |
446 | ||
447 | SHOW(temp0, temp0, null_adjust) /* temp1_input */ | |
448 | SHOW(temp1, temp1, null_adjust) /* temp2_input */ | |
449 | ||
450 | ||
451 | /* sysfs conventions report voltages in millivolts. We can convert voltages | |
452 | * if we know vREF. userspace may need to scale vAUX to match the board's | |
453 | * external resistors; we assume that vBATT only uses the internal ones. | |
454 | */ | |
455 | static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) | |
456 | { | |
457 | unsigned retval = v; | |
458 | ||
459 | /* external resistors may scale vAUX into 0..vREF */ | |
460 | retval *= ts->vref_mv; | |
461 | retval = retval >> 12; | |
462 | ||
463 | return retval; | |
464 | } | |
465 | ||
466 | static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) | |
467 | { | |
468 | unsigned retval = vaux_adjust(ts, v); | |
469 | ||
470 | /* ads7846 has a resistor ladder to scale this signal down */ | |
471 | if (ts->model == 7846) | |
472 | retval *= 4; | |
473 | ||
474 | return retval; | |
475 | } | |
476 | ||
477 | SHOW(in0_input, vaux, vaux_adjust) | |
478 | SHOW(in1_input, vbatt, vbatt_adjust) | |
479 | ||
480 | static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, | |
481 | int index) | |
482 | { | |
483 | struct device *dev = container_of(kobj, struct device, kobj); | |
484 | struct ads7846 *ts = dev_get_drvdata(dev); | |
485 | ||
486 | if (ts->model == 7843 && index < 2) /* in0, in1 */ | |
487 | return 0; | |
488 | if (ts->model == 7845 && index != 2) /* in0 */ | |
489 | return 0; | |
490 | ||
491 | return attr->mode; | |
492 | } | |
493 | ||
494 | static struct attribute *ads7846_attributes[] = { | |
495 | &dev_attr_temp0.attr, /* 0 */ | |
496 | &dev_attr_temp1.attr, /* 1 */ | |
497 | &dev_attr_in0_input.attr, /* 2 */ | |
498 | &dev_attr_in1_input.attr, /* 3 */ | |
499 | NULL, | |
500 | }; | |
501 | ||
502 | static struct attribute_group ads7846_attr_group = { | |
503 | .attrs = ads7846_attributes, | |
504 | .is_visible = ads7846_is_visible, | |
505 | }; | |
506 | __ATTRIBUTE_GROUPS(ads7846_attr); | |
507 | ||
508 | static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) | |
509 | { | |
510 | /* hwmon sensors need a reference voltage */ | |
511 | switch (ts->model) { | |
512 | case 7846: | |
513 | if (!ts->vref_mv) { | |
514 | dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); | |
515 | ts->vref_mv = 2500; | |
516 | ts->use_internal = true; | |
517 | } | |
518 | break; | |
519 | case 7845: | |
520 | case 7843: | |
521 | if (!ts->vref_mv) { | |
522 | dev_warn(&spi->dev, | |
523 | "external vREF for ADS%d not specified\n", | |
524 | ts->model); | |
525 | return 0; | |
526 | } | |
527 | break; | |
528 | } | |
529 | ||
530 | ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, | |
531 | ts, ads7846_attr_groups); | |
532 | ||
533 | return PTR_ERR_OR_ZERO(ts->hwmon); | |
534 | } | |
535 | ||
536 | static void ads784x_hwmon_unregister(struct spi_device *spi, | |
537 | struct ads7846 *ts) | |
538 | { | |
539 | if (ts->hwmon) | |
540 | hwmon_device_unregister(ts->hwmon); | |
541 | } | |
542 | ||
543 | #else | |
544 | static inline int ads784x_hwmon_register(struct spi_device *spi, | |
545 | struct ads7846 *ts) | |
546 | { | |
547 | return 0; | |
548 | } | |
549 | ||
550 | static inline void ads784x_hwmon_unregister(struct spi_device *spi, | |
551 | struct ads7846 *ts) | |
552 | { | |
553 | } | |
554 | #endif | |
555 | ||
556 | static ssize_t ads7846_pen_down_show(struct device *dev, | |
557 | struct device_attribute *attr, char *buf) | |
558 | { | |
559 | struct ads7846 *ts = dev_get_drvdata(dev); | |
560 | ||
561 | return sprintf(buf, "%u\n", ts->pendown); | |
562 | } | |
563 | ||
564 | static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); | |
565 | ||
566 | static ssize_t ads7846_disable_show(struct device *dev, | |
567 | struct device_attribute *attr, char *buf) | |
568 | { | |
569 | struct ads7846 *ts = dev_get_drvdata(dev); | |
570 | ||
571 | return sprintf(buf, "%u\n", ts->disabled); | |
572 | } | |
573 | ||
574 | static ssize_t ads7846_disable_store(struct device *dev, | |
575 | struct device_attribute *attr, | |
576 | const char *buf, size_t count) | |
577 | { | |
578 | struct ads7846 *ts = dev_get_drvdata(dev); | |
579 | unsigned int i; | |
580 | int err; | |
581 | ||
582 | err = kstrtouint(buf, 10, &i); | |
583 | if (err) | |
584 | return err; | |
585 | ||
586 | if (i) | |
587 | ads7846_disable(ts); | |
588 | else | |
589 | ads7846_enable(ts); | |
590 | ||
591 | return count; | |
592 | } | |
593 | ||
594 | static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); | |
595 | ||
596 | static struct attribute *ads784x_attributes[] = { | |
597 | &dev_attr_pen_down.attr, | |
598 | &dev_attr_disable.attr, | |
599 | NULL, | |
600 | }; | |
601 | ||
602 | static struct attribute_group ads784x_attr_group = { | |
603 | .attrs = ads784x_attributes, | |
604 | }; | |
605 | ||
606 | /*--------------------------------------------------------------------------*/ | |
607 | ||
608 | static int get_pendown_state(struct ads7846 *ts) | |
609 | { | |
610 | if (ts->get_pendown_state) | |
611 | return ts->get_pendown_state(); | |
612 | ||
613 | return !gpio_get_value(ts->gpio_pendown); | |
614 | } | |
615 | ||
616 | static void null_wait_for_sync(void) | |
617 | { | |
618 | } | |
619 | ||
620 | static int ads7846_debounce_filter(void *ads, int data_idx, int *val) | |
621 | { | |
622 | struct ads7846 *ts = ads; | |
623 | ||
624 | if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { | |
625 | /* Start over collecting consistent readings. */ | |
626 | ts->read_rep = 0; | |
627 | /* | |
628 | * Repeat it, if this was the first read or the read | |
629 | * wasn't consistent enough. | |
630 | */ | |
631 | if (ts->read_cnt < ts->debounce_max) { | |
632 | ts->last_read = *val; | |
633 | ts->read_cnt++; | |
634 | return ADS7846_FILTER_REPEAT; | |
635 | } else { | |
636 | /* | |
637 | * Maximum number of debouncing reached and still | |
638 | * not enough number of consistent readings. Abort | |
639 | * the whole sample, repeat it in the next sampling | |
640 | * period. | |
641 | */ | |
642 | ts->read_cnt = 0; | |
643 | return ADS7846_FILTER_IGNORE; | |
644 | } | |
645 | } else { | |
646 | if (++ts->read_rep > ts->debounce_rep) { | |
647 | /* | |
648 | * Got a good reading for this coordinate, | |
649 | * go for the next one. | |
650 | */ | |
651 | ts->read_cnt = 0; | |
652 | ts->read_rep = 0; | |
653 | return ADS7846_FILTER_OK; | |
654 | } else { | |
655 | /* Read more values that are consistent. */ | |
656 | ts->read_cnt++; | |
657 | return ADS7846_FILTER_REPEAT; | |
658 | } | |
659 | } | |
660 | } | |
661 | ||
662 | static int ads7846_no_filter(void *ads, int data_idx, int *val) | |
663 | { | |
664 | return ADS7846_FILTER_OK; | |
665 | } | |
666 | ||
667 | static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) | |
668 | { | |
669 | int value; | |
670 | struct spi_transfer *t = | |
671 | list_entry(m->transfers.prev, struct spi_transfer, transfer_list); | |
672 | ||
673 | if (ts->model == 7845) { | |
674 | value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); | |
675 | } else { | |
676 | /* | |
677 | * adjust: on-wire is a must-ignore bit, a BE12 value, then | |
678 | * padding; built from two 8 bit values written msb-first. | |
679 | */ | |
680 | value = be16_to_cpup((__be16 *)t->rx_buf); | |
681 | } | |
682 | ||
683 | /* enforce ADC output is 12 bits width */ | |
684 | return (value >> 3) & 0xfff; | |
685 | } | |
686 | ||
687 | static void ads7846_update_value(struct spi_message *m, int val) | |
688 | { | |
689 | struct spi_transfer *t = | |
690 | list_entry(m->transfers.prev, struct spi_transfer, transfer_list); | |
691 | ||
692 | *(u16 *)t->rx_buf = val; | |
693 | } | |
694 | ||
695 | static void ads7846_read_state(struct ads7846 *ts) | |
696 | { | |
697 | struct ads7846_packet *packet = ts->packet; | |
698 | struct spi_message *m; | |
699 | int msg_idx = 0; | |
700 | int val; | |
701 | int action; | |
702 | int error; | |
703 | ||
704 | while (msg_idx < ts->msg_count) { | |
705 | ||
706 | ts->wait_for_sync(); | |
707 | ||
708 | m = &ts->msg[msg_idx]; | |
709 | error = spi_sync(ts->spi, m); | |
710 | if (error) { | |
711 | dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); | |
712 | packet->tc.ignore = true; | |
713 | return; | |
714 | } | |
715 | ||
716 | /* | |
717 | * Last message is power down request, no need to convert | |
718 | * or filter the value. | |
719 | */ | |
720 | if (msg_idx < ts->msg_count - 1) { | |
721 | ||
722 | val = ads7846_get_value(ts, m); | |
723 | ||
724 | action = ts->filter(ts->filter_data, msg_idx, &val); | |
725 | switch (action) { | |
726 | case ADS7846_FILTER_REPEAT: | |
727 | continue; | |
728 | ||
729 | case ADS7846_FILTER_IGNORE: | |
730 | packet->tc.ignore = true; | |
731 | msg_idx = ts->msg_count - 1; | |
732 | continue; | |
733 | ||
734 | case ADS7846_FILTER_OK: | |
735 | ads7846_update_value(m, val); | |
736 | packet->tc.ignore = false; | |
737 | msg_idx++; | |
738 | break; | |
739 | ||
740 | default: | |
741 | BUG(); | |
742 | } | |
743 | } else { | |
744 | msg_idx++; | |
745 | } | |
746 | } | |
747 | } | |
748 | ||
749 | static void ads7846_report_state(struct ads7846 *ts) | |
750 | { | |
751 | struct ads7846_packet *packet = ts->packet; | |
752 | unsigned int Rt; | |
753 | u16 x, y, z1, z2; | |
754 | ||
755 | /* | |
756 | * ads7846_get_value() does in-place conversion (including byte swap) | |
757 | * from on-the-wire format as part of debouncing to get stable | |
758 | * readings. | |
759 | */ | |
760 | if (ts->model == 7845) { | |
761 | x = *(u16 *)packet->tc.x_buf; | |
762 | y = *(u16 *)packet->tc.y_buf; | |
763 | z1 = 0; | |
764 | z2 = 0; | |
765 | } else { | |
766 | x = packet->tc.x; | |
767 | y = packet->tc.y; | |
768 | z1 = packet->tc.z1; | |
769 | z2 = packet->tc.z2; | |
770 | } | |
771 | ||
772 | /* range filtering */ | |
773 | if (x == MAX_12BIT) | |
774 | x = 0; | |
775 | ||
776 | if (ts->model == 7843) { | |
777 | Rt = ts->pressure_max / 2; | |
778 | } else if (ts->model == 7845) { | |
779 | if (get_pendown_state(ts)) | |
780 | Rt = ts->pressure_max / 2; | |
781 | else | |
782 | Rt = 0; | |
783 | dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); | |
784 | } else if (likely(x && z1)) { | |
785 | /* compute touch pressure resistance using equation #2 */ | |
786 | Rt = z2; | |
787 | Rt -= z1; | |
788 | Rt *= x; | |
789 | Rt *= ts->x_plate_ohms; | |
790 | Rt /= z1; | |
791 | Rt = (Rt + 2047) >> 12; | |
792 | } else { | |
793 | Rt = 0; | |
794 | } | |
795 | ||
796 | /* | |
797 | * Sample found inconsistent by debouncing or pressure is beyond | |
798 | * the maximum. Don't report it to user space, repeat at least | |
799 | * once more the measurement | |
800 | */ | |
801 | if (packet->tc.ignore || Rt > ts->pressure_max) { | |
802 | dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", | |
803 | packet->tc.ignore, Rt); | |
804 | return; | |
805 | } | |
806 | ||
807 | /* | |
808 | * Maybe check the pendown state before reporting. This discards | |
809 | * false readings when the pen is lifted. | |
810 | */ | |
811 | if (ts->penirq_recheck_delay_usecs) { | |
812 | udelay(ts->penirq_recheck_delay_usecs); | |
813 | if (!get_pendown_state(ts)) | |
814 | Rt = 0; | |
815 | } | |
816 | ||
817 | /* | |
818 | * NOTE: We can't rely on the pressure to determine the pen down | |
819 | * state, even this controller has a pressure sensor. The pressure | |
820 | * value can fluctuate for quite a while after lifting the pen and | |
821 | * in some cases may not even settle at the expected value. | |
822 | * | |
823 | * The only safe way to check for the pen up condition is in the | |
824 | * timer by reading the pen signal state (it's a GPIO _and_ IRQ). | |
825 | */ | |
826 | if (Rt) { | |
827 | struct input_dev *input = ts->input; | |
828 | ||
829 | if (ts->swap_xy) | |
830 | swap(x, y); | |
831 | ||
832 | if (!ts->pendown) { | |
833 | input_report_key(input, BTN_TOUCH, 1); | |
834 | ts->pendown = true; | |
835 | dev_vdbg(&ts->spi->dev, "DOWN\n"); | |
836 | } | |
837 | ||
838 | input_report_abs(input, ABS_X, x); | |
839 | input_report_abs(input, ABS_Y, y); | |
840 | input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); | |
841 | ||
842 | input_sync(input); | |
843 | dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); | |
844 | } | |
845 | } | |
846 | ||
847 | static irqreturn_t ads7846_hard_irq(int irq, void *handle) | |
848 | { | |
849 | struct ads7846 *ts = handle; | |
850 | ||
851 | return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; | |
852 | } | |
853 | ||
854 | ||
855 | static irqreturn_t ads7846_irq(int irq, void *handle) | |
856 | { | |
857 | struct ads7846 *ts = handle; | |
858 | ||
859 | /* Start with a small delay before checking pendown state */ | |
860 | msleep(TS_POLL_DELAY); | |
861 | ||
862 | while (!ts->stopped && get_pendown_state(ts)) { | |
863 | ||
864 | /* pen is down, continue with the measurement */ | |
865 | ads7846_read_state(ts); | |
866 | ||
867 | if (!ts->stopped) | |
868 | ads7846_report_state(ts); | |
869 | ||
870 | wait_event_timeout(ts->wait, ts->stopped, | |
871 | msecs_to_jiffies(TS_POLL_PERIOD)); | |
872 | } | |
873 | ||
874 | if (ts->pendown) { | |
875 | struct input_dev *input = ts->input; | |
876 | ||
877 | input_report_key(input, BTN_TOUCH, 0); | |
878 | input_report_abs(input, ABS_PRESSURE, 0); | |
879 | input_sync(input); | |
880 | ||
881 | ts->pendown = false; | |
882 | dev_vdbg(&ts->spi->dev, "UP\n"); | |
883 | } | |
884 | ||
885 | return IRQ_HANDLED; | |
886 | } | |
887 | ||
888 | static int __maybe_unused ads7846_suspend(struct device *dev) | |
889 | { | |
890 | struct ads7846 *ts = dev_get_drvdata(dev); | |
891 | ||
892 | mutex_lock(&ts->lock); | |
893 | ||
894 | if (!ts->suspended) { | |
895 | ||
896 | if (!ts->disabled) | |
897 | __ads7846_disable(ts); | |
898 | ||
899 | if (device_may_wakeup(&ts->spi->dev)) | |
900 | enable_irq_wake(ts->spi->irq); | |
901 | ||
902 | ts->suspended = true; | |
903 | } | |
904 | ||
905 | mutex_unlock(&ts->lock); | |
906 | ||
907 | return 0; | |
908 | } | |
909 | ||
910 | static int __maybe_unused ads7846_resume(struct device *dev) | |
911 | { | |
912 | struct ads7846 *ts = dev_get_drvdata(dev); | |
913 | ||
914 | mutex_lock(&ts->lock); | |
915 | ||
916 | if (ts->suspended) { | |
917 | ||
918 | ts->suspended = false; | |
919 | ||
920 | if (device_may_wakeup(&ts->spi->dev)) | |
921 | disable_irq_wake(ts->spi->irq); | |
922 | ||
923 | if (!ts->disabled) | |
924 | __ads7846_enable(ts); | |
925 | } | |
926 | ||
927 | mutex_unlock(&ts->lock); | |
928 | ||
929 | return 0; | |
930 | } | |
931 | ||
932 | static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); | |
933 | ||
934 | static int ads7846_setup_pendown(struct spi_device *spi, | |
935 | struct ads7846 *ts, | |
936 | const struct ads7846_platform_data *pdata) | |
937 | { | |
938 | int err; | |
939 | ||
940 | /* | |
941 | * REVISIT when the irq can be triggered active-low, or if for some | |
942 | * reason the touchscreen isn't hooked up, we don't need to access | |
943 | * the pendown state. | |
944 | */ | |
945 | ||
946 | if (pdata->get_pendown_state) { | |
947 | ts->get_pendown_state = pdata->get_pendown_state; | |
948 | } else if (gpio_is_valid(pdata->gpio_pendown)) { | |
949 | ||
950 | err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, | |
951 | "ads7846_pendown"); | |
952 | if (err) { | |
953 | dev_err(&spi->dev, | |
954 | "failed to request/setup pendown GPIO%d: %d\n", | |
955 | pdata->gpio_pendown, err); | |
956 | return err; | |
957 | } | |
958 | ||
959 | ts->gpio_pendown = pdata->gpio_pendown; | |
960 | ||
961 | if (pdata->gpio_pendown_debounce) | |
962 | gpio_set_debounce(pdata->gpio_pendown, | |
963 | pdata->gpio_pendown_debounce); | |
964 | } else { | |
965 | dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); | |
966 | return -EINVAL; | |
967 | } | |
968 | ||
969 | return 0; | |
970 | } | |
971 | ||
972 | /* | |
973 | * Set up the transfers to read touchscreen state; this assumes we | |
974 | * use formula #2 for pressure, not #3. | |
975 | */ | |
976 | static void ads7846_setup_spi_msg(struct ads7846 *ts, | |
977 | const struct ads7846_platform_data *pdata) | |
978 | { | |
979 | struct spi_message *m = &ts->msg[0]; | |
980 | struct spi_transfer *x = ts->xfer; | |
981 | struct ads7846_packet *packet = ts->packet; | |
982 | int vref = pdata->keep_vref_on; | |
983 | ||
984 | if (ts->model == 7873) { | |
985 | /* | |
986 | * The AD7873 is almost identical to the ADS7846 | |
987 | * keep VREF off during differential/ratiometric | |
988 | * conversion modes. | |
989 | */ | |
990 | ts->model = 7846; | |
991 | vref = 0; | |
992 | } | |
993 | ||
994 | ts->msg_count = 1; | |
995 | spi_message_init(m); | |
996 | m->context = ts; | |
997 | ||
998 | if (ts->model == 7845) { | |
999 | packet->read_y_cmd[0] = READ_Y(vref); | |
1000 | packet->read_y_cmd[1] = 0; | |
1001 | packet->read_y_cmd[2] = 0; | |
1002 | x->tx_buf = &packet->read_y_cmd[0]; | |
1003 | x->rx_buf = &packet->tc.y_buf[0]; | |
1004 | x->len = 3; | |
1005 | spi_message_add_tail(x, m); | |
1006 | } else { | |
1007 | /* y- still on; turn on only y+ (and ADC) */ | |
1008 | packet->read_y = READ_Y(vref); | |
1009 | x->tx_buf = &packet->read_y; | |
1010 | x->len = 1; | |
1011 | spi_message_add_tail(x, m); | |
1012 | ||
1013 | x++; | |
1014 | x->rx_buf = &packet->tc.y; | |
1015 | x->len = 2; | |
1016 | spi_message_add_tail(x, m); | |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * The first sample after switching drivers can be low quality; | |
1021 | * optionally discard it, using a second one after the signals | |
1022 | * have had enough time to stabilize. | |
1023 | */ | |
1024 | if (pdata->settle_delay_usecs) { | |
1025 | x->delay_usecs = pdata->settle_delay_usecs; | |
1026 | ||
1027 | x++; | |
1028 | x->tx_buf = &packet->read_y; | |
1029 | x->len = 1; | |
1030 | spi_message_add_tail(x, m); | |
1031 | ||
1032 | x++; | |
1033 | x->rx_buf = &packet->tc.y; | |
1034 | x->len = 2; | |
1035 | spi_message_add_tail(x, m); | |
1036 | } | |
1037 | ||
1038 | ts->msg_count++; | |
1039 | m++; | |
1040 | spi_message_init(m); | |
1041 | m->context = ts; | |
1042 | ||
1043 | if (ts->model == 7845) { | |
1044 | x++; | |
1045 | packet->read_x_cmd[0] = READ_X(vref); | |
1046 | packet->read_x_cmd[1] = 0; | |
1047 | packet->read_x_cmd[2] = 0; | |
1048 | x->tx_buf = &packet->read_x_cmd[0]; | |
1049 | x->rx_buf = &packet->tc.x_buf[0]; | |
1050 | x->len = 3; | |
1051 | spi_message_add_tail(x, m); | |
1052 | } else { | |
1053 | /* turn y- off, x+ on, then leave in lowpower */ | |
1054 | x++; | |
1055 | packet->read_x = READ_X(vref); | |
1056 | x->tx_buf = &packet->read_x; | |
1057 | x->len = 1; | |
1058 | spi_message_add_tail(x, m); | |
1059 | ||
1060 | x++; | |
1061 | x->rx_buf = &packet->tc.x; | |
1062 | x->len = 2; | |
1063 | spi_message_add_tail(x, m); | |
1064 | } | |
1065 | ||
1066 | /* ... maybe discard first sample ... */ | |
1067 | if (pdata->settle_delay_usecs) { | |
1068 | x->delay_usecs = pdata->settle_delay_usecs; | |
1069 | ||
1070 | x++; | |
1071 | x->tx_buf = &packet->read_x; | |
1072 | x->len = 1; | |
1073 | spi_message_add_tail(x, m); | |
1074 | ||
1075 | x++; | |
1076 | x->rx_buf = &packet->tc.x; | |
1077 | x->len = 2; | |
1078 | spi_message_add_tail(x, m); | |
1079 | } | |
1080 | ||
1081 | /* turn y+ off, x- on; we'll use formula #2 */ | |
1082 | if (ts->model == 7846) { | |
1083 | ts->msg_count++; | |
1084 | m++; | |
1085 | spi_message_init(m); | |
1086 | m->context = ts; | |
1087 | ||
1088 | x++; | |
1089 | packet->read_z1 = READ_Z1(vref); | |
1090 | x->tx_buf = &packet->read_z1; | |
1091 | x->len = 1; | |
1092 | spi_message_add_tail(x, m); | |
1093 | ||
1094 | x++; | |
1095 | x->rx_buf = &packet->tc.z1; | |
1096 | x->len = 2; | |
1097 | spi_message_add_tail(x, m); | |
1098 | ||
1099 | /* ... maybe discard first sample ... */ | |
1100 | if (pdata->settle_delay_usecs) { | |
1101 | x->delay_usecs = pdata->settle_delay_usecs; | |
1102 | ||
1103 | x++; | |
1104 | x->tx_buf = &packet->read_z1; | |
1105 | x->len = 1; | |
1106 | spi_message_add_tail(x, m); | |
1107 | ||
1108 | x++; | |
1109 | x->rx_buf = &packet->tc.z1; | |
1110 | x->len = 2; | |
1111 | spi_message_add_tail(x, m); | |
1112 | } | |
1113 | ||
1114 | ts->msg_count++; | |
1115 | m++; | |
1116 | spi_message_init(m); | |
1117 | m->context = ts; | |
1118 | ||
1119 | x++; | |
1120 | packet->read_z2 = READ_Z2(vref); | |
1121 | x->tx_buf = &packet->read_z2; | |
1122 | x->len = 1; | |
1123 | spi_message_add_tail(x, m); | |
1124 | ||
1125 | x++; | |
1126 | x->rx_buf = &packet->tc.z2; | |
1127 | x->len = 2; | |
1128 | spi_message_add_tail(x, m); | |
1129 | ||
1130 | /* ... maybe discard first sample ... */ | |
1131 | if (pdata->settle_delay_usecs) { | |
1132 | x->delay_usecs = pdata->settle_delay_usecs; | |
1133 | ||
1134 | x++; | |
1135 | x->tx_buf = &packet->read_z2; | |
1136 | x->len = 1; | |
1137 | spi_message_add_tail(x, m); | |
1138 | ||
1139 | x++; | |
1140 | x->rx_buf = &packet->tc.z2; | |
1141 | x->len = 2; | |
1142 | spi_message_add_tail(x, m); | |
1143 | } | |
1144 | } | |
1145 | ||
1146 | /* power down */ | |
1147 | ts->msg_count++; | |
1148 | m++; | |
1149 | spi_message_init(m); | |
1150 | m->context = ts; | |
1151 | ||
1152 | if (ts->model == 7845) { | |
1153 | x++; | |
1154 | packet->pwrdown_cmd[0] = PWRDOWN; | |
1155 | packet->pwrdown_cmd[1] = 0; | |
1156 | packet->pwrdown_cmd[2] = 0; | |
1157 | x->tx_buf = &packet->pwrdown_cmd[0]; | |
1158 | x->len = 3; | |
1159 | } else { | |
1160 | x++; | |
1161 | packet->pwrdown = PWRDOWN; | |
1162 | x->tx_buf = &packet->pwrdown; | |
1163 | x->len = 1; | |
1164 | spi_message_add_tail(x, m); | |
1165 | ||
1166 | x++; | |
1167 | x->rx_buf = &packet->dummy; | |
1168 | x->len = 2; | |
1169 | } | |
1170 | ||
1171 | CS_CHANGE(*x); | |
1172 | spi_message_add_tail(x, m); | |
1173 | } | |
1174 | ||
1175 | #ifdef CONFIG_OF | |
1176 | static const struct of_device_id ads7846_dt_ids[] = { | |
1177 | { .compatible = "ti,tsc2046", .data = (void *) 7846 }, | |
1178 | { .compatible = "ti,ads7843", .data = (void *) 7843 }, | |
1179 | { .compatible = "ti,ads7845", .data = (void *) 7845 }, | |
1180 | { .compatible = "ti,ads7846", .data = (void *) 7846 }, | |
1181 | { .compatible = "ti,ads7873", .data = (void *) 7873 }, | |
1182 | { } | |
1183 | }; | |
1184 | MODULE_DEVICE_TABLE(of, ads7846_dt_ids); | |
1185 | ||
1186 | static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) | |
1187 | { | |
1188 | struct ads7846_platform_data *pdata; | |
1189 | struct device_node *node = dev->of_node; | |
1190 | const struct of_device_id *match; | |
1191 | ||
1192 | if (!node) { | |
1193 | dev_err(dev, "Device does not have associated DT data\n"); | |
1194 | return ERR_PTR(-EINVAL); | |
1195 | } | |
1196 | ||
1197 | match = of_match_device(ads7846_dt_ids, dev); | |
1198 | if (!match) { | |
1199 | dev_err(dev, "Unknown device model\n"); | |
1200 | return ERR_PTR(-EINVAL); | |
1201 | } | |
1202 | ||
1203 | pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); | |
1204 | if (!pdata) | |
1205 | return ERR_PTR(-ENOMEM); | |
1206 | ||
1207 | pdata->model = (unsigned long)match->data; | |
1208 | ||
1209 | of_property_read_u16(node, "ti,vref-delay-usecs", | |
1210 | &pdata->vref_delay_usecs); | |
1211 | of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); | |
1212 | pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); | |
1213 | ||
1214 | pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); | |
1215 | ||
1216 | of_property_read_u16(node, "ti,settle-delay-usec", | |
1217 | &pdata->settle_delay_usecs); | |
1218 | of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", | |
1219 | &pdata->penirq_recheck_delay_usecs); | |
1220 | ||
1221 | of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); | |
1222 | of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); | |
1223 | ||
1224 | of_property_read_u16(node, "ti,x-min", &pdata->x_min); | |
1225 | of_property_read_u16(node, "ti,y-min", &pdata->y_min); | |
1226 | of_property_read_u16(node, "ti,x-max", &pdata->x_max); | |
1227 | of_property_read_u16(node, "ti,y-max", &pdata->y_max); | |
1228 | ||
1229 | of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); | |
1230 | of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); | |
1231 | ||
1232 | of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); | |
1233 | of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); | |
1234 | of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); | |
1235 | ||
1236 | of_property_read_u32(node, "ti,pendown-gpio-debounce", | |
1237 | &pdata->gpio_pendown_debounce); | |
1238 | ||
1239 | pdata->wakeup = of_property_read_bool(node, "wakeup-source") || | |
1240 | of_property_read_bool(node, "linux,wakeup"); | |
1241 | ||
1242 | pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); | |
1243 | ||
1244 | return pdata; | |
1245 | } | |
1246 | #else | |
1247 | static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) | |
1248 | { | |
1249 | dev_err(dev, "no platform data defined\n"); | |
1250 | return ERR_PTR(-EINVAL); | |
1251 | } | |
1252 | #endif | |
1253 | ||
1254 | static int ads7846_probe(struct spi_device *spi) | |
1255 | { | |
1256 | const struct ads7846_platform_data *pdata; | |
1257 | struct ads7846 *ts; | |
1258 | struct ads7846_packet *packet; | |
1259 | struct input_dev *input_dev; | |
1260 | unsigned long irq_flags; | |
1261 | int err; | |
1262 | ||
1263 | if (!spi->irq) { | |
1264 | dev_dbg(&spi->dev, "no IRQ?\n"); | |
1265 | return -EINVAL; | |
1266 | } | |
1267 | ||
1268 | /* don't exceed max specified sample rate */ | |
1269 | if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { | |
1270 | dev_err(&spi->dev, "f(sample) %d KHz?\n", | |
1271 | (spi->max_speed_hz/SAMPLE_BITS)/1000); | |
1272 | return -EINVAL; | |
1273 | } | |
1274 | ||
1275 | /* | |
1276 | * We'd set TX word size 8 bits and RX word size to 13 bits ... except | |
1277 | * that even if the hardware can do that, the SPI controller driver | |
1278 | * may not. So we stick to very-portable 8 bit words, both RX and TX. | |
1279 | */ | |
1280 | spi->bits_per_word = 8; | |
1281 | spi->mode = SPI_MODE_0; | |
1282 | err = spi_setup(spi); | |
1283 | if (err < 0) | |
1284 | return err; | |
1285 | ||
1286 | ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); | |
1287 | packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); | |
1288 | input_dev = input_allocate_device(); | |
1289 | if (!ts || !packet || !input_dev) { | |
1290 | err = -ENOMEM; | |
1291 | goto err_free_mem; | |
1292 | } | |
1293 | ||
1294 | spi_set_drvdata(spi, ts); | |
1295 | ||
1296 | ts->packet = packet; | |
1297 | ts->spi = spi; | |
1298 | ts->input = input_dev; | |
1299 | ||
1300 | mutex_init(&ts->lock); | |
1301 | init_waitqueue_head(&ts->wait); | |
1302 | ||
1303 | pdata = dev_get_platdata(&spi->dev); | |
1304 | if (!pdata) { | |
1305 | pdata = ads7846_probe_dt(&spi->dev); | |
1306 | if (IS_ERR(pdata)) { | |
1307 | err = PTR_ERR(pdata); | |
1308 | goto err_free_mem; | |
1309 | } | |
1310 | } | |
1311 | ||
1312 | ts->model = pdata->model ? : 7846; | |
1313 | ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; | |
1314 | ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; | |
1315 | ts->pressure_max = pdata->pressure_max ? : ~0; | |
1316 | ||
1317 | ts->vref_mv = pdata->vref_mv; | |
1318 | ts->swap_xy = pdata->swap_xy; | |
1319 | ||
1320 | if (pdata->filter != NULL) { | |
1321 | if (pdata->filter_init != NULL) { | |
1322 | err = pdata->filter_init(pdata, &ts->filter_data); | |
1323 | if (err < 0) | |
1324 | goto err_free_mem; | |
1325 | } | |
1326 | ts->filter = pdata->filter; | |
1327 | ts->filter_cleanup = pdata->filter_cleanup; | |
1328 | } else if (pdata->debounce_max) { | |
1329 | ts->debounce_max = pdata->debounce_max; | |
1330 | if (ts->debounce_max < 2) | |
1331 | ts->debounce_max = 2; | |
1332 | ts->debounce_tol = pdata->debounce_tol; | |
1333 | ts->debounce_rep = pdata->debounce_rep; | |
1334 | ts->filter = ads7846_debounce_filter; | |
1335 | ts->filter_data = ts; | |
1336 | } else { | |
1337 | ts->filter = ads7846_no_filter; | |
1338 | } | |
1339 | ||
1340 | err = ads7846_setup_pendown(spi, ts, pdata); | |
1341 | if (err) | |
1342 | goto err_cleanup_filter; | |
1343 | ||
1344 | if (pdata->penirq_recheck_delay_usecs) | |
1345 | ts->penirq_recheck_delay_usecs = | |
1346 | pdata->penirq_recheck_delay_usecs; | |
1347 | ||
1348 | ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; | |
1349 | ||
1350 | snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); | |
1351 | snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); | |
1352 | ||
1353 | input_dev->name = ts->name; | |
1354 | input_dev->phys = ts->phys; | |
1355 | input_dev->dev.parent = &spi->dev; | |
1356 | ||
1357 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); | |
1358 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); | |
1359 | input_set_abs_params(input_dev, ABS_X, | |
1360 | pdata->x_min ? : 0, | |
1361 | pdata->x_max ? : MAX_12BIT, | |
1362 | 0, 0); | |
1363 | input_set_abs_params(input_dev, ABS_Y, | |
1364 | pdata->y_min ? : 0, | |
1365 | pdata->y_max ? : MAX_12BIT, | |
1366 | 0, 0); | |
1367 | input_set_abs_params(input_dev, ABS_PRESSURE, | |
1368 | pdata->pressure_min, pdata->pressure_max, 0, 0); | |
1369 | ||
1370 | ads7846_setup_spi_msg(ts, pdata); | |
1371 | ||
1372 | ts->reg = regulator_get(&spi->dev, "vcc"); | |
1373 | if (IS_ERR(ts->reg)) { | |
1374 | err = PTR_ERR(ts->reg); | |
1375 | dev_err(&spi->dev, "unable to get regulator: %d\n", err); | |
1376 | goto err_free_gpio; | |
1377 | } | |
1378 | ||
1379 | err = regulator_enable(ts->reg); | |
1380 | if (err) { | |
1381 | dev_err(&spi->dev, "unable to enable regulator: %d\n", err); | |
1382 | goto err_put_regulator; | |
1383 | } | |
1384 | ||
1385 | irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; | |
1386 | irq_flags |= IRQF_ONESHOT; | |
1387 | ||
1388 | err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, | |
1389 | irq_flags, spi->dev.driver->name, ts); | |
1390 | if (err && !pdata->irq_flags) { | |
1391 | dev_info(&spi->dev, | |
1392 | "trying pin change workaround on irq %d\n", spi->irq); | |
1393 | irq_flags |= IRQF_TRIGGER_RISING; | |
1394 | err = request_threaded_irq(spi->irq, | |
1395 | ads7846_hard_irq, ads7846_irq, | |
1396 | irq_flags, spi->dev.driver->name, ts); | |
1397 | } | |
1398 | ||
1399 | if (err) { | |
1400 | dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); | |
1401 | goto err_disable_regulator; | |
1402 | } | |
1403 | ||
1404 | err = ads784x_hwmon_register(spi, ts); | |
1405 | if (err) | |
1406 | goto err_free_irq; | |
1407 | ||
1408 | dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); | |
1409 | ||
1410 | /* | |
1411 | * Take a first sample, leaving nPENIRQ active and vREF off; avoid | |
1412 | * the touchscreen, in case it's not connected. | |
1413 | */ | |
1414 | if (ts->model == 7845) | |
1415 | ads7845_read12_ser(&spi->dev, PWRDOWN); | |
1416 | else | |
1417 | (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); | |
1418 | ||
1419 | err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); | |
1420 | if (err) | |
1421 | goto err_remove_hwmon; | |
1422 | ||
1423 | err = input_register_device(input_dev); | |
1424 | if (err) | |
1425 | goto err_remove_attr_group; | |
1426 | ||
1427 | device_init_wakeup(&spi->dev, pdata->wakeup); | |
1428 | ||
1429 | /* | |
1430 | * If device does not carry platform data we must have allocated it | |
1431 | * when parsing DT data. | |
1432 | */ | |
1433 | if (!dev_get_platdata(&spi->dev)) | |
1434 | devm_kfree(&spi->dev, (void *)pdata); | |
1435 | ||
1436 | return 0; | |
1437 | ||
1438 | err_remove_attr_group: | |
1439 | sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); | |
1440 | err_remove_hwmon: | |
1441 | ads784x_hwmon_unregister(spi, ts); | |
1442 | err_free_irq: | |
1443 | free_irq(spi->irq, ts); | |
1444 | err_disable_regulator: | |
1445 | regulator_disable(ts->reg); | |
1446 | err_put_regulator: | |
1447 | regulator_put(ts->reg); | |
1448 | err_free_gpio: | |
1449 | if (!ts->get_pendown_state) | |
1450 | gpio_free(ts->gpio_pendown); | |
1451 | err_cleanup_filter: | |
1452 | if (ts->filter_cleanup) | |
1453 | ts->filter_cleanup(ts->filter_data); | |
1454 | err_free_mem: | |
1455 | input_free_device(input_dev); | |
1456 | kfree(packet); | |
1457 | kfree(ts); | |
1458 | return err; | |
1459 | } | |
1460 | ||
1461 | static int ads7846_remove(struct spi_device *spi) | |
1462 | { | |
1463 | struct ads7846 *ts = spi_get_drvdata(spi); | |
1464 | ||
1465 | device_init_wakeup(&spi->dev, false); | |
1466 | ||
1467 | sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); | |
1468 | ||
1469 | ads7846_disable(ts); | |
1470 | free_irq(ts->spi->irq, ts); | |
1471 | ||
1472 | input_unregister_device(ts->input); | |
1473 | ||
1474 | ads784x_hwmon_unregister(spi, ts); | |
1475 | ||
1476 | regulator_put(ts->reg); | |
1477 | ||
1478 | if (!ts->get_pendown_state) { | |
1479 | /* | |
1480 | * If we are not using specialized pendown method we must | |
1481 | * have been relying on gpio we set up ourselves. | |
1482 | */ | |
1483 | gpio_free(ts->gpio_pendown); | |
1484 | } | |
1485 | ||
1486 | if (ts->filter_cleanup) | |
1487 | ts->filter_cleanup(ts->filter_data); | |
1488 | ||
1489 | kfree(ts->packet); | |
1490 | kfree(ts); | |
1491 | ||
1492 | dev_dbg(&spi->dev, "unregistered touchscreen\n"); | |
1493 | ||
1494 | return 0; | |
1495 | } | |
1496 | ||
1497 | static struct spi_driver ads7846_driver = { | |
1498 | .driver = { | |
1499 | .name = "ads7846", | |
1500 | .pm = &ads7846_pm, | |
1501 | .of_match_table = of_match_ptr(ads7846_dt_ids), | |
1502 | }, | |
1503 | .probe = ads7846_probe, | |
1504 | .remove = ads7846_remove, | |
1505 | }; | |
1506 | ||
1507 | module_spi_driver(ads7846_driver); | |
1508 | ||
1509 | MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); | |
1510 | MODULE_LICENSE("GPL"); | |
1511 | MODULE_ALIAS("spi:ads7846"); |