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Commit | Line | Data |
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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 | */ | |
2c8dc071 | 20 | #include <linux/hwmon.h> |
ffa458c1 | 21 | #include <linux/init.h> |
2c8dc071 | 22 | #include <linux/err.h> |
ffa458c1 DB |
23 | #include <linux/delay.h> |
24 | #include <linux/input.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/slab.h> | |
4d5975e5 | 27 | #include <linux/gpio.h> |
ffa458c1 DB |
28 | #include <linux/spi/spi.h> |
29 | #include <linux/spi/ads7846.h> | |
3ac8bf07 | 30 | #include <asm/irq.h> |
ffa458c1 | 31 | |
ffa458c1 | 32 | /* |
9084533e | 33 | * This code has been heavily tested on a Nokia 770, and lightly |
52ce4eaa | 34 | * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). |
bff0de5f | 35 | * TSC2046 is just newer ads7846 silicon. |
969111e9 NF |
36 | * Support for ads7843 tested on Atmel at91sam926x-EK. |
37 | * Support for ads7845 has only been stubbed in. | |
ffa458c1 | 38 | * |
7de90a8c ID |
39 | * IRQ handling needs a workaround because of a shortcoming in handling |
40 | * edge triggered IRQs on some platforms like the OMAP1/2. These | |
41 | * platforms don't handle the ARM lazy IRQ disabling properly, thus we | |
42 | * have to maintain our own SW IRQ disabled status. This should be | |
43 | * removed as soon as the affected platform's IRQ handling is fixed. | |
44 | * | |
52ce4eaa | 45 | * App note sbaa036 talks in more detail about accurate sampling... |
ffa458c1 DB |
46 | * that ought to help in situations like LCDs inducing noise (which |
47 | * can also be helped by using synch signals) and more generally. | |
7de90a8c ID |
48 | * This driver tries to utilize the measures described in the app |
49 | * note. The strength of filtering can be set in the board-* specific | |
50 | * files. | |
ffa458c1 DB |
51 | */ |
52 | ||
1936d590 ID |
53 | #define TS_POLL_DELAY (1 * 1000000) /* ns delay before the first sample */ |
54 | #define TS_POLL_PERIOD (5 * 1000000) /* ns delay between samples */ | |
ffa458c1 | 55 | |
d93f70b2 DB |
56 | /* this driver doesn't aim at the peak continuous sample rate */ |
57 | #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) | |
58 | ||
ffa458c1 DB |
59 | struct ts_event { |
60 | /* For portability, we can't read 12 bit values using SPI (which | |
61 | * would make the controller deliver them as native byteorder u16 | |
d93f70b2 | 62 | * with msbs zeroed). Instead, we read them as two 8-bit values, |
da970e69 | 63 | * *** WHICH NEED BYTESWAPPING *** and range adjustment. |
ffa458c1 | 64 | */ |
da970e69 ID |
65 | u16 x; |
66 | u16 y; | |
67 | u16 z1, z2; | |
2c8dc071 | 68 | int ignore; |
ffa458c1 DB |
69 | }; |
70 | ||
e8f462d2 DT |
71 | /* |
72 | * We allocate this separately to avoid cache line sharing issues when | |
73 | * driver is used with DMA-based SPI controllers (like atmel_spi) on | |
74 | * systems where main memory is not DMA-coherent (most non-x86 boards). | |
75 | */ | |
76 | struct ads7846_packet { | |
77 | u8 read_x, read_y, read_z1, read_z2, pwrdown; | |
78 | u16 dummy; /* for the pwrdown read */ | |
79 | struct ts_event tc; | |
80 | }; | |
81 | ||
ffa458c1 | 82 | struct ads7846 { |
a90f7e98 | 83 | struct input_dev *input; |
ffa458c1 | 84 | char phys[32]; |
b58895f8 | 85 | char name[32]; |
ffa458c1 DB |
86 | |
87 | struct spi_device *spi; | |
2c8dc071 DB |
88 | |
89 | #if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE) | |
8dd51650 | 90 | struct attribute_group *attr_group; |
1beeffe4 | 91 | struct device *hwmon; |
2c8dc071 DB |
92 | #endif |
93 | ||
ffa458c1 | 94 | u16 model; |
7c6d0ee1 | 95 | u16 vref_mv; |
ffa458c1 DB |
96 | u16 vref_delay_usecs; |
97 | u16 x_plate_ohms; | |
d5b415c9 | 98 | u16 pressure_max; |
ffa458c1 | 99 | |
86579a4c MR |
100 | bool swap_xy; |
101 | ||
e8f462d2 | 102 | struct ads7846_packet *packet; |
ffa458c1 | 103 | |
e4f48861 | 104 | struct spi_transfer xfer[18]; |
0b7018aa | 105 | struct spi_message msg[5]; |
d5b415c9 | 106 | struct spi_message *last_msg; |
0b7018aa ID |
107 | int msg_idx; |
108 | int read_cnt; | |
d5b415c9 | 109 | int read_rep; |
0b7018aa ID |
110 | int last_read; |
111 | ||
112 | u16 debounce_max; | |
113 | u16 debounce_tol; | |
d5b415c9 | 114 | u16 debounce_rep; |
ffa458c1 | 115 | |
1d25891f SH |
116 | u16 penirq_recheck_delay_usecs; |
117 | ||
ffa458c1 | 118 | spinlock_t lock; |
1936d590 | 119 | struct hrtimer timer; |
ffa458c1 DB |
120 | unsigned pendown:1; /* P: lock */ |
121 | unsigned pending:1; /* P: lock */ | |
122 | // FIXME remove "irq_disabled" | |
123 | unsigned irq_disabled:1; /* P: lock */ | |
7de90a8c | 124 | unsigned disabled:1; |
fbb38e30 | 125 | unsigned is_suspended:1; |
c9e617a5 | 126 | |
da970e69 ID |
127 | int (*filter)(void *data, int data_idx, int *val); |
128 | void *filter_data; | |
129 | void (*filter_cleanup)(void *data); | |
c9e617a5 | 130 | int (*get_pendown_state)(void); |
4d5975e5 | 131 | int gpio_pendown; |
fd746d54 EM |
132 | |
133 | void (*wait_for_sync)(void); | |
ffa458c1 DB |
134 | }; |
135 | ||
136 | /* leave chip selected when we're done, for quicker re-select? */ | |
137 | #if 0 | |
138 | #define CS_CHANGE(xfer) ((xfer).cs_change = 1) | |
139 | #else | |
140 | #define CS_CHANGE(xfer) ((xfer).cs_change = 0) | |
141 | #endif | |
142 | ||
143 | /*--------------------------------------------------------------------------*/ | |
144 | ||
145 | /* The ADS7846 has touchscreen and other sensors. | |
146 | * Earlier ads784x chips are somewhat compatible. | |
147 | */ | |
148 | #define ADS_START (1 << 7) | |
149 | #define ADS_A2A1A0_d_y (1 << 4) /* differential */ | |
150 | #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ | |
151 | #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ | |
152 | #define ADS_A2A1A0_d_x (5 << 4) /* differential */ | |
153 | #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ | |
154 | #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ | |
155 | #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ | |
156 | #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ | |
157 | #define ADS_8_BIT (1 << 3) | |
158 | #define ADS_12_BIT (0 << 3) | |
159 | #define ADS_SER (1 << 2) /* non-differential */ | |
160 | #define ADS_DFR (0 << 2) /* differential */ | |
161 | #define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */ | |
162 | #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ | |
163 | #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ | |
164 | #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ | |
165 | ||
166 | #define MAX_12BIT ((1<<12)-1) | |
167 | ||
168 | /* leave ADC powered up (disables penirq) between differential samples */ | |
de2defd9 ID |
169 | #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ |
170 | | ADS_12_BIT | ADS_DFR | \ | |
171 | (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) | |
ffa458c1 | 172 | |
de2defd9 ID |
173 | #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) |
174 | #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) | |
175 | #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) | |
53a0ef89 | 176 | |
de2defd9 ID |
177 | #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) |
178 | #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ | |
ffa458c1 DB |
179 | |
180 | /* single-ended samples need to first power up reference voltage; | |
181 | * we leave both ADC and VREF powered | |
182 | */ | |
183 | #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ | |
184 | | ADS_12_BIT | ADS_SER) | |
185 | ||
de2defd9 ID |
186 | #define REF_ON (READ_12BIT_DFR(x, 1, 1)) |
187 | #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) | |
ffa458c1 DB |
188 | |
189 | /*--------------------------------------------------------------------------*/ | |
190 | ||
191 | /* | |
192 | * Non-touchscreen sensors only use single-ended conversions. | |
2c8dc071 DB |
193 | * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; |
194 | * ads7846 lets that pin be unconnected, to use internal vREF. | |
ffa458c1 DB |
195 | */ |
196 | ||
197 | struct ser_req { | |
d93f70b2 | 198 | u8 ref_on; |
ffa458c1 | 199 | u8 command; |
d93f70b2 | 200 | u8 ref_off; |
ffa458c1 DB |
201 | u16 scratch; |
202 | __be16 sample; | |
203 | struct spi_message msg; | |
204 | struct spi_transfer xfer[6]; | |
205 | }; | |
206 | ||
7de90a8c ID |
207 | static void ads7846_enable(struct ads7846 *ts); |
208 | static void ads7846_disable(struct ads7846 *ts); | |
209 | ||
c9e617a5 ID |
210 | static int device_suspended(struct device *dev) |
211 | { | |
212 | struct ads7846 *ts = dev_get_drvdata(dev); | |
fbb38e30 | 213 | return ts->is_suspended || ts->disabled; |
c9e617a5 ID |
214 | } |
215 | ||
ffa458c1 DB |
216 | static int ads7846_read12_ser(struct device *dev, unsigned command) |
217 | { | |
218 | struct spi_device *spi = to_spi_device(dev); | |
219 | struct ads7846 *ts = dev_get_drvdata(dev); | |
e94b1766 | 220 | struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL); |
ffa458c1 | 221 | int status; |
2c8dc071 | 222 | int use_internal; |
ffa458c1 DB |
223 | |
224 | if (!req) | |
225 | return -ENOMEM; | |
226 | ||
0b7018aa | 227 | spi_message_init(&req->msg); |
8275c642 | 228 | |
2c8dc071 DB |
229 | /* FIXME boards with ads7846 might use external vref instead ... */ |
230 | use_internal = (ts->model == 7846); | |
231 | ||
232 | /* maybe turn on internal vREF, and let it settle */ | |
233 | if (use_internal) { | |
234 | req->ref_on = REF_ON; | |
235 | req->xfer[0].tx_buf = &req->ref_on; | |
236 | req->xfer[0].len = 1; | |
237 | spi_message_add_tail(&req->xfer[0], &req->msg); | |
238 | ||
239 | req->xfer[1].rx_buf = &req->scratch; | |
240 | req->xfer[1].len = 2; | |
241 | ||
242 | /* for 1uF, settle for 800 usec; no cap, 100 usec. */ | |
243 | req->xfer[1].delay_usecs = ts->vref_delay_usecs; | |
244 | spi_message_add_tail(&req->xfer[1], &req->msg); | |
245 | } | |
ffa458c1 DB |
246 | |
247 | /* take sample */ | |
248 | req->command = (u8) command; | |
249 | req->xfer[2].tx_buf = &req->command; | |
250 | req->xfer[2].len = 1; | |
2c8dc071 DB |
251 | spi_message_add_tail(&req->xfer[2], &req->msg); |
252 | ||
ffa458c1 DB |
253 | req->xfer[3].rx_buf = &req->sample; |
254 | req->xfer[3].len = 2; | |
2c8dc071 | 255 | spi_message_add_tail(&req->xfer[3], &req->msg); |
ffa458c1 DB |
256 | |
257 | /* REVISIT: take a few more samples, and compare ... */ | |
258 | ||
969111e9 NF |
259 | /* converter in low power mode & enable PENIRQ */ |
260 | req->ref_off = PWRDOWN; | |
261 | req->xfer[4].tx_buf = &req->ref_off; | |
262 | req->xfer[4].len = 1; | |
263 | spi_message_add_tail(&req->xfer[4], &req->msg); | |
264 | ||
265 | req->xfer[5].rx_buf = &req->scratch; | |
266 | req->xfer[5].len = 2; | |
267 | CS_CHANGE(req->xfer[5]); | |
268 | spi_message_add_tail(&req->xfer[5], &req->msg); | |
ffa458c1 | 269 | |
c9e617a5 | 270 | ts->irq_disabled = 1; |
ffa458c1 DB |
271 | disable_irq(spi->irq); |
272 | status = spi_sync(spi, &req->msg); | |
c9e617a5 | 273 | ts->irq_disabled = 0; |
ffa458c1 DB |
274 | enable_irq(spi->irq); |
275 | ||
c24b2602 MP |
276 | if (status == 0) { |
277 | /* on-wire is a must-ignore bit, a BE12 value, then padding */ | |
7c6d0ee1 DB |
278 | status = be16_to_cpu(req->sample); |
279 | status = status >> 3; | |
280 | status &= 0x0fff; | |
c24b2602 | 281 | } |
ffa458c1 | 282 | |
9084533e | 283 | kfree(req); |
7c6d0ee1 | 284 | return status; |
ffa458c1 DB |
285 | } |
286 | ||
2c8dc071 DB |
287 | #if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE) |
288 | ||
289 | #define SHOW(name, var, adjust) static ssize_t \ | |
ffa458c1 DB |
290 | name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ |
291 | { \ | |
2c8dc071 | 292 | struct ads7846 *ts = dev_get_drvdata(dev); \ |
ffa458c1 | 293 | ssize_t v = ads7846_read12_ser(dev, \ |
2c8dc071 | 294 | READ_12BIT_SER(var) | ADS_PD10_ALL_ON); \ |
ffa458c1 DB |
295 | if (v < 0) \ |
296 | return v; \ | |
2c8dc071 | 297 | return sprintf(buf, "%u\n", adjust(ts, v)); \ |
ffa458c1 DB |
298 | } \ |
299 | static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); | |
300 | ||
2c8dc071 | 301 | |
b731d7b6 | 302 | /* Sysfs conventions report temperatures in millidegrees Celsius. |
2c8dc071 DB |
303 | * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high |
304 | * accuracy scheme without calibration data. For now we won't try either; | |
305 | * userspace sees raw sensor values, and must scale/calibrate appropriately. | |
306 | */ | |
307 | static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) | |
308 | { | |
309 | return v; | |
310 | } | |
311 | ||
312 | SHOW(temp0, temp0, null_adjust) /* temp1_input */ | |
313 | SHOW(temp1, temp1, null_adjust) /* temp2_input */ | |
314 | ||
315 | ||
316 | /* sysfs conventions report voltages in millivolts. We can convert voltages | |
317 | * if we know vREF. userspace may need to scale vAUX to match the board's | |
318 | * external resistors; we assume that vBATT only uses the internal ones. | |
319 | */ | |
320 | static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) | |
321 | { | |
322 | unsigned retval = v; | |
323 | ||
324 | /* external resistors may scale vAUX into 0..vREF */ | |
7c6d0ee1 | 325 | retval *= ts->vref_mv; |
2c8dc071 DB |
326 | retval = retval >> 12; |
327 | return retval; | |
328 | } | |
329 | ||
330 | static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) | |
331 | { | |
332 | unsigned retval = vaux_adjust(ts, v); | |
333 | ||
334 | /* ads7846 has a resistor ladder to scale this signal down */ | |
335 | if (ts->model == 7846) | |
336 | retval *= 4; | |
337 | return retval; | |
338 | } | |
339 | ||
340 | SHOW(in0_input, vaux, vaux_adjust) | |
341 | SHOW(in1_input, vbatt, vbatt_adjust) | |
342 | ||
343 | ||
344 | static struct attribute *ads7846_attributes[] = { | |
345 | &dev_attr_temp0.attr, | |
346 | &dev_attr_temp1.attr, | |
347 | &dev_attr_in0_input.attr, | |
348 | &dev_attr_in1_input.attr, | |
349 | NULL, | |
350 | }; | |
351 | ||
352 | static struct attribute_group ads7846_attr_group = { | |
353 | .attrs = ads7846_attributes, | |
354 | }; | |
355 | ||
356 | static struct attribute *ads7843_attributes[] = { | |
357 | &dev_attr_in0_input.attr, | |
358 | &dev_attr_in1_input.attr, | |
359 | NULL, | |
360 | }; | |
361 | ||
362 | static struct attribute_group ads7843_attr_group = { | |
363 | .attrs = ads7843_attributes, | |
364 | }; | |
365 | ||
366 | static struct attribute *ads7845_attributes[] = { | |
367 | &dev_attr_in0_input.attr, | |
368 | NULL, | |
369 | }; | |
370 | ||
371 | static struct attribute_group ads7845_attr_group = { | |
372 | .attrs = ads7845_attributes, | |
373 | }; | |
374 | ||
375 | static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) | |
376 | { | |
1beeffe4 | 377 | struct device *hwmon; |
2c8dc071 DB |
378 | int err; |
379 | ||
380 | /* hwmon sensors need a reference voltage */ | |
381 | switch (ts->model) { | |
382 | case 7846: | |
7c6d0ee1 | 383 | if (!ts->vref_mv) { |
2c8dc071 | 384 | dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); |
7c6d0ee1 | 385 | ts->vref_mv = 2500; |
2c8dc071 DB |
386 | } |
387 | break; | |
388 | case 7845: | |
389 | case 7843: | |
7c6d0ee1 | 390 | if (!ts->vref_mv) { |
2c8dc071 DB |
391 | dev_warn(&spi->dev, |
392 | "external vREF for ADS%d not specified\n", | |
393 | ts->model); | |
394 | return 0; | |
395 | } | |
396 | break; | |
397 | } | |
398 | ||
399 | /* different chips have different sensor groups */ | |
400 | switch (ts->model) { | |
401 | case 7846: | |
402 | ts->attr_group = &ads7846_attr_group; | |
403 | break; | |
404 | case 7845: | |
405 | ts->attr_group = &ads7845_attr_group; | |
406 | break; | |
407 | case 7843: | |
408 | ts->attr_group = &ads7843_attr_group; | |
409 | break; | |
410 | default: | |
411 | dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model); | |
412 | return 0; | |
413 | } | |
414 | ||
415 | err = sysfs_create_group(&spi->dev.kobj, ts->attr_group); | |
416 | if (err) | |
417 | return err; | |
418 | ||
419 | hwmon = hwmon_device_register(&spi->dev); | |
420 | if (IS_ERR(hwmon)) { | |
421 | sysfs_remove_group(&spi->dev.kobj, ts->attr_group); | |
422 | return PTR_ERR(hwmon); | |
423 | } | |
424 | ||
425 | ts->hwmon = hwmon; | |
426 | return 0; | |
427 | } | |
428 | ||
429 | static void ads784x_hwmon_unregister(struct spi_device *spi, | |
430 | struct ads7846 *ts) | |
431 | { | |
432 | if (ts->hwmon) { | |
433 | sysfs_remove_group(&spi->dev.kobj, ts->attr_group); | |
434 | hwmon_device_unregister(ts->hwmon); | |
435 | } | |
436 | } | |
437 | ||
438 | #else | |
439 | static inline int ads784x_hwmon_register(struct spi_device *spi, | |
440 | struct ads7846 *ts) | |
441 | { | |
442 | return 0; | |
443 | } | |
444 | ||
445 | static inline void ads784x_hwmon_unregister(struct spi_device *spi, | |
446 | struct ads7846 *ts) | |
447 | { | |
448 | } | |
449 | #endif | |
ffa458c1 | 450 | |
438f2a74 ID |
451 | static int is_pen_down(struct device *dev) |
452 | { | |
2c8dc071 | 453 | struct ads7846 *ts = dev_get_drvdata(dev); |
438f2a74 ID |
454 | |
455 | return ts->pendown; | |
456 | } | |
457 | ||
458 | static ssize_t ads7846_pen_down_show(struct device *dev, | |
459 | struct device_attribute *attr, char *buf) | |
460 | { | |
461 | return sprintf(buf, "%u\n", is_pen_down(dev)); | |
462 | } | |
463 | ||
464 | static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); | |
465 | ||
7de90a8c ID |
466 | static ssize_t ads7846_disable_show(struct device *dev, |
467 | struct device_attribute *attr, char *buf) | |
468 | { | |
469 | struct ads7846 *ts = dev_get_drvdata(dev); | |
470 | ||
471 | return sprintf(buf, "%u\n", ts->disabled); | |
472 | } | |
473 | ||
474 | static ssize_t ads7846_disable_store(struct device *dev, | |
475 | struct device_attribute *attr, | |
476 | const char *buf, size_t count) | |
477 | { | |
478 | struct ads7846 *ts = dev_get_drvdata(dev); | |
3a0c58dd | 479 | unsigned long i; |
160f1fef JR |
480 | |
481 | if (strict_strtoul(buf, 10, &i)) | |
482 | return -EINVAL; | |
7de90a8c | 483 | |
7de90a8c ID |
484 | spin_lock_irq(&ts->lock); |
485 | ||
486 | if (i) | |
487 | ads7846_disable(ts); | |
488 | else | |
489 | ads7846_enable(ts); | |
490 | ||
491 | spin_unlock_irq(&ts->lock); | |
492 | ||
493 | return count; | |
494 | } | |
495 | ||
496 | static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); | |
497 | ||
2c8dc071 | 498 | static struct attribute *ads784x_attributes[] = { |
8dd51650 DT |
499 | &dev_attr_pen_down.attr, |
500 | &dev_attr_disable.attr, | |
501 | NULL, | |
502 | }; | |
503 | ||
2c8dc071 DB |
504 | static struct attribute_group ads784x_attr_group = { |
505 | .attrs = ads784x_attributes, | |
8dd51650 DT |
506 | }; |
507 | ||
ffa458c1 DB |
508 | /*--------------------------------------------------------------------------*/ |
509 | ||
4d5975e5 EM |
510 | static int get_pendown_state(struct ads7846 *ts) |
511 | { | |
512 | if (ts->get_pendown_state) | |
513 | return ts->get_pendown_state(); | |
514 | ||
515 | return !gpio_get_value(ts->gpio_pendown); | |
516 | } | |
517 | ||
fd746d54 EM |
518 | static void null_wait_for_sync(void) |
519 | { | |
520 | } | |
521 | ||
ffa458c1 DB |
522 | /* |
523 | * PENIRQ only kicks the timer. The timer only reissues the SPI transfer, | |
524 | * to retrieve touchscreen status. | |
525 | * | |
526 | * The SPI transfer completion callback does the real work. It reports | |
527 | * touchscreen events and reactivates the timer (or IRQ) as appropriate. | |
528 | */ | |
529 | ||
530 | static void ads7846_rx(void *ads) | |
531 | { | |
a90f7e98 | 532 | struct ads7846 *ts = ads; |
e8f462d2 | 533 | struct ads7846_packet *packet = ts->packet; |
a90f7e98 | 534 | unsigned Rt; |
a90f7e98 | 535 | u16 x, y, z1, z2; |
ffa458c1 | 536 | |
da970e69 ID |
537 | /* ads7846_rx_val() did in-place conversion (including byteswap) from |
538 | * on-the-wire format as part of debouncing to get stable readings. | |
ffa458c1 | 539 | */ |
e8f462d2 DT |
540 | x = packet->tc.x; |
541 | y = packet->tc.y; | |
542 | z1 = packet->tc.z1; | |
543 | z2 = packet->tc.z2; | |
ffa458c1 DB |
544 | |
545 | /* range filtering */ | |
546 | if (x == MAX_12BIT) | |
547 | x = 0; | |
548 | ||
9460b652 HCE |
549 | if (ts->model == 7843) { |
550 | Rt = ts->pressure_max / 2; | |
551 | } else if (likely(x && z1)) { | |
ffa458c1 DB |
552 | /* compute touch pressure resistance using equation #2 */ |
553 | Rt = z2; | |
554 | Rt -= z1; | |
555 | Rt *= x; | |
556 | Rt *= ts->x_plate_ohms; | |
557 | Rt /= z1; | |
558 | Rt = (Rt + 2047) >> 12; | |
9460b652 | 559 | } else { |
ffa458c1 | 560 | Rt = 0; |
9460b652 | 561 | } |
969111e9 | 562 | |
d5b415c9 | 563 | /* Sample found inconsistent by debouncing or pressure is beyond |
1936d590 ID |
564 | * the maximum. Don't report it to user space, repeat at least |
565 | * once more the measurement | |
566 | */ | |
e8f462d2 | 567 | if (packet->tc.ignore || Rt > ts->pressure_max) { |
52ce4eaa PM |
568 | dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", |
569 | packet->tc.ignore, Rt); | |
1936d590 | 570 | hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), |
c9cb2e3d | 571 | HRTIMER_MODE_REL); |
d5b415c9 ID |
572 | return; |
573 | } | |
574 | ||
1d25891f SH |
575 | /* Maybe check the pendown state before reporting. This discards |
576 | * false readings when the pen is lifted. | |
577 | */ | |
578 | if (ts->penirq_recheck_delay_usecs) { | |
579 | udelay(ts->penirq_recheck_delay_usecs); | |
4d5975e5 | 580 | if (!get_pendown_state(ts)) |
1d25891f SH |
581 | Rt = 0; |
582 | } | |
583 | ||
15e3589e ID |
584 | /* NOTE: We can't rely on the pressure to determine the pen down |
585 | * state, even this controller has a pressure sensor. The pressure | |
586 | * value can fluctuate for quite a while after lifting the pen and | |
587 | * in some cases may not even settle at the expected value. | |
ffa458c1 | 588 | * |
15e3589e ID |
589 | * The only safe way to check for the pen up condition is in the |
590 | * timer by reading the pen signal state (it's a GPIO _and_ IRQ). | |
ffa458c1 | 591 | */ |
ffa458c1 | 592 | if (Rt) { |
15e3589e | 593 | struct input_dev *input = ts->input; |
ae82d5ab | 594 | |
15e3589e ID |
595 | if (!ts->pendown) { |
596 | input_report_key(input, BTN_TOUCH, 1); | |
597 | ts->pendown = 1; | |
52ce4eaa | 598 | dev_vdbg(&ts->spi->dev, "DOWN\n"); |
15e3589e | 599 | } |
86579a4c MR |
600 | |
601 | if (ts->swap_xy) | |
602 | swap(x, y); | |
603 | ||
15e3589e ID |
604 | input_report_abs(input, ABS_X, x); |
605 | input_report_abs(input, ABS_Y, y); | |
30ad7ba0 | 606 | input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); |
ffa458c1 | 607 | |
15e3589e | 608 | input_sync(input); |
52ce4eaa | 609 | dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); |
15e3589e | 610 | } |
ffa458c1 | 611 | |
c9cb2e3d TG |
612 | hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), |
613 | HRTIMER_MODE_REL); | |
ffa458c1 DB |
614 | } |
615 | ||
da970e69 | 616 | static int ads7846_debounce(void *ads, int data_idx, int *val) |
0b7018aa ID |
617 | { |
618 | struct ads7846 *ts = ads; | |
0b7018aa | 619 | |
da970e69 ID |
620 | if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { |
621 | /* Start over collecting consistent readings. */ | |
622 | ts->read_rep = 0; | |
d5b415c9 ID |
623 | /* Repeat it, if this was the first read or the read |
624 | * wasn't consistent enough. */ | |
625 | if (ts->read_cnt < ts->debounce_max) { | |
da970e69 | 626 | ts->last_read = *val; |
d5b415c9 | 627 | ts->read_cnt++; |
da970e69 | 628 | return ADS7846_FILTER_REPEAT; |
d5b415c9 ID |
629 | } else { |
630 | /* Maximum number of debouncing reached and still | |
631 | * not enough number of consistent readings. Abort | |
632 | * the whole sample, repeat it in the next sampling | |
633 | * period. | |
634 | */ | |
d5b415c9 | 635 | ts->read_cnt = 0; |
da970e69 | 636 | return ADS7846_FILTER_IGNORE; |
d5b415c9 | 637 | } |
0b7018aa | 638 | } else { |
d5b415c9 ID |
639 | if (++ts->read_rep > ts->debounce_rep) { |
640 | /* Got a good reading for this coordinate, | |
641 | * go for the next one. */ | |
d5b415c9 ID |
642 | ts->read_cnt = 0; |
643 | ts->read_rep = 0; | |
da970e69 ID |
644 | return ADS7846_FILTER_OK; |
645 | } else { | |
d5b415c9 ID |
646 | /* Read more values that are consistent. */ |
647 | ts->read_cnt++; | |
da970e69 ID |
648 | return ADS7846_FILTER_REPEAT; |
649 | } | |
650 | } | |
651 | } | |
652 | ||
653 | static int ads7846_no_filter(void *ads, int data_idx, int *val) | |
654 | { | |
655 | return ADS7846_FILTER_OK; | |
656 | } | |
657 | ||
658 | static void ads7846_rx_val(void *ads) | |
659 | { | |
660 | struct ads7846 *ts = ads; | |
e8f462d2 | 661 | struct ads7846_packet *packet = ts->packet; |
da970e69 ID |
662 | struct spi_message *m; |
663 | struct spi_transfer *t; | |
da970e69 ID |
664 | int val; |
665 | int action; | |
666 | int status; | |
667 | ||
668 | m = &ts->msg[ts->msg_idx]; | |
669 | t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list); | |
da970e69 ID |
670 | |
671 | /* adjust: on-wire is a must-ignore bit, a BE12 value, then padding; | |
672 | * built from two 8 bit values written msb-first. | |
673 | */ | |
494f6857 | 674 | val = be16_to_cpup((__be16 *)t->rx_buf) >> 3; |
da970e69 ID |
675 | |
676 | action = ts->filter(ts->filter_data, ts->msg_idx, &val); | |
677 | switch (action) { | |
678 | case ADS7846_FILTER_REPEAT: | |
679 | break; | |
680 | case ADS7846_FILTER_IGNORE: | |
e8f462d2 | 681 | packet->tc.ignore = 1; |
da970e69 ID |
682 | /* Last message will contain ads7846_rx() as the |
683 | * completion function. | |
684 | */ | |
685 | m = ts->last_msg; | |
686 | break; | |
687 | case ADS7846_FILTER_OK: | |
494f6857 | 688 | *(u16 *)t->rx_buf = val; |
e8f462d2 | 689 | packet->tc.ignore = 0; |
da970e69 ID |
690 | m = &ts->msg[++ts->msg_idx]; |
691 | break; | |
692 | default: | |
693 | BUG(); | |
0b7018aa | 694 | } |
fd746d54 | 695 | ts->wait_for_sync(); |
0b7018aa ID |
696 | status = spi_async(ts->spi, m); |
697 | if (status) | |
698 | dev_err(&ts->spi->dev, "spi_async --> %d\n", | |
699 | status); | |
700 | } | |
701 | ||
c9cb2e3d | 702 | static enum hrtimer_restart ads7846_timer(struct hrtimer *handle) |
ffa458c1 | 703 | { |
1936d590 | 704 | struct ads7846 *ts = container_of(handle, struct ads7846, timer); |
ffa458c1 | 705 | int status = 0; |
0b7018aa | 706 | |
ca109491 | 707 | spin_lock(&ts->lock); |
c9e617a5 | 708 | |
4d5975e5 | 709 | if (unlikely(!get_pendown_state(ts) || |
15e3589e ID |
710 | device_suspended(&ts->spi->dev))) { |
711 | if (ts->pendown) { | |
712 | struct input_dev *input = ts->input; | |
713 | ||
714 | input_report_key(input, BTN_TOUCH, 0); | |
715 | input_report_abs(input, ABS_PRESSURE, 0); | |
716 | input_sync(input); | |
717 | ||
718 | ts->pendown = 0; | |
52ce4eaa | 719 | dev_vdbg(&ts->spi->dev, "UP\n"); |
15e3589e ID |
720 | } |
721 | ||
9084533e | 722 | /* measurement cycle ended */ |
c9e617a5 ID |
723 | if (!device_suspended(&ts->spi->dev)) { |
724 | ts->irq_disabled = 0; | |
725 | enable_irq(ts->spi->irq); | |
726 | } | |
727 | ts->pending = 0; | |
c9e617a5 ID |
728 | } else { |
729 | /* pen is still down, continue with the measurement */ | |
730 | ts->msg_idx = 0; | |
fd746d54 | 731 | ts->wait_for_sync(); |
c9e617a5 ID |
732 | status = spi_async(ts->spi, &ts->msg[0]); |
733 | if (status) | |
734 | dev_err(&ts->spi->dev, "spi_async --> %d\n", status); | |
735 | } | |
736 | ||
ca109491 | 737 | spin_unlock(&ts->lock); |
1936d590 | 738 | return HRTIMER_NORESTART; |
0b7018aa ID |
739 | } |
740 | ||
7d12e780 | 741 | static irqreturn_t ads7846_irq(int irq, void *handle) |
0b7018aa ID |
742 | { |
743 | struct ads7846 *ts = handle; | |
744 | unsigned long flags; | |
ffa458c1 DB |
745 | |
746 | spin_lock_irqsave(&ts->lock, flags); | |
4d5975e5 | 747 | if (likely(get_pendown_state(ts))) { |
ffa458c1 | 748 | if (!ts->irq_disabled) { |
9084533e DB |
749 | /* The ARM do_simple_IRQ() dispatcher doesn't act |
750 | * like the other dispatchers: it will report IRQs | |
751 | * even after they've been disabled. We work around | |
752 | * that here. (The "generic irq" framework may help...) | |
0b7018aa | 753 | */ |
ffa458c1 | 754 | ts->irq_disabled = 1; |
3f3e7c6e | 755 | disable_irq_nosync(ts->spi->irq); |
0b7018aa | 756 | ts->pending = 1; |
1936d590 | 757 | hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY), |
c9cb2e3d | 758 | HRTIMER_MODE_REL); |
0b7018aa | 759 | } |
ffa458c1 DB |
760 | } |
761 | spin_unlock_irqrestore(&ts->lock, flags); | |
7de90a8c ID |
762 | |
763 | return IRQ_HANDLED; | |
ffa458c1 DB |
764 | } |
765 | ||
766 | /*--------------------------------------------------------------------------*/ | |
767 | ||
7de90a8c ID |
768 | /* Must be called with ts->lock held */ |
769 | static void ads7846_disable(struct ads7846 *ts) | |
ffa458c1 | 770 | { |
7de90a8c ID |
771 | if (ts->disabled) |
772 | return; | |
ffa458c1 | 773 | |
c9e617a5 ID |
774 | ts->disabled = 1; |
775 | ||
ffa458c1 | 776 | /* are we waiting for IRQ, or polling? */ |
c9e617a5 ID |
777 | if (!ts->pending) { |
778 | ts->irq_disabled = 1; | |
779 | disable_irq(ts->spi->irq); | |
ffa458c1 | 780 | } else { |
c9e617a5 ID |
781 | /* the timer will run at least once more, and |
782 | * leave everything in a clean state, IRQ disabled | |
ffa458c1 | 783 | */ |
c9e617a5 | 784 | while (ts->pending) { |
7de90a8c | 785 | spin_unlock_irq(&ts->lock); |
c4febb94 | 786 | msleep(1); |
7de90a8c | 787 | spin_lock_irq(&ts->lock); |
ffa458c1 DB |
788 | } |
789 | } | |
790 | ||
791 | /* we know the chip's in lowpower mode since we always | |
792 | * leave it that way after every request | |
793 | */ | |
7de90a8c ID |
794 | } |
795 | ||
796 | /* Must be called with ts->lock held */ | |
797 | static void ads7846_enable(struct ads7846 *ts) | |
798 | { | |
799 | if (!ts->disabled) | |
800 | return; | |
801 | ||
802 | ts->disabled = 0; | |
803 | ts->irq_disabled = 0; | |
804 | enable_irq(ts->spi->irq); | |
805 | } | |
806 | ||
807 | static int ads7846_suspend(struct spi_device *spi, pm_message_t message) | |
808 | { | |
809 | struct ads7846 *ts = dev_get_drvdata(&spi->dev); | |
810 | ||
811 | spin_lock_irq(&ts->lock); | |
812 | ||
fbb38e30 | 813 | ts->is_suspended = 1; |
7de90a8c ID |
814 | ads7846_disable(ts); |
815 | ||
816 | spin_unlock_irq(&ts->lock); | |
817 | ||
ffa458c1 | 818 | return 0; |
7de90a8c | 819 | |
ffa458c1 DB |
820 | } |
821 | ||
2e5a7bd9 | 822 | static int ads7846_resume(struct spi_device *spi) |
ffa458c1 | 823 | { |
2e5a7bd9 | 824 | struct ads7846 *ts = dev_get_drvdata(&spi->dev); |
ffa458c1 | 825 | |
7de90a8c ID |
826 | spin_lock_irq(&ts->lock); |
827 | ||
fbb38e30 | 828 | ts->is_suspended = 0; |
7de90a8c ID |
829 | ads7846_enable(ts); |
830 | ||
831 | spin_unlock_irq(&ts->lock); | |
832 | ||
ffa458c1 DB |
833 | return 0; |
834 | } | |
835 | ||
4d5975e5 EM |
836 | static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts) |
837 | { | |
838 | struct ads7846_platform_data *pdata = spi->dev.platform_data; | |
839 | int err; | |
840 | ||
841 | /* REVISIT when the irq can be triggered active-low, or if for some | |
842 | * reason the touchscreen isn't hooked up, we don't need to access | |
843 | * the pendown state. | |
844 | */ | |
845 | if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) { | |
846 | dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); | |
847 | return -EINVAL; | |
848 | } | |
849 | ||
850 | if (pdata->get_pendown_state) { | |
851 | ts->get_pendown_state = pdata->get_pendown_state; | |
852 | return 0; | |
853 | } | |
854 | ||
855 | err = gpio_request(pdata->gpio_pendown, "ads7846_pendown"); | |
856 | if (err) { | |
857 | dev_err(&spi->dev, "failed to request pendown GPIO%d\n", | |
858 | pdata->gpio_pendown); | |
859 | return err; | |
860 | } | |
861 | ||
862 | ts->gpio_pendown = pdata->gpio_pendown; | |
863 | return 0; | |
864 | } | |
865 | ||
2e5a7bd9 | 866 | static int __devinit ads7846_probe(struct spi_device *spi) |
ffa458c1 | 867 | { |
ffa458c1 | 868 | struct ads7846 *ts; |
e8f462d2 | 869 | struct ads7846_packet *packet; |
a90f7e98 | 870 | struct input_dev *input_dev; |
2e5a7bd9 | 871 | struct ads7846_platform_data *pdata = spi->dev.platform_data; |
0b7018aa | 872 | struct spi_message *m; |
ffa458c1 | 873 | struct spi_transfer *x; |
de2defd9 | 874 | int vref; |
a90f7e98 | 875 | int err; |
ffa458c1 DB |
876 | |
877 | if (!spi->irq) { | |
2e5a7bd9 | 878 | dev_dbg(&spi->dev, "no IRQ?\n"); |
ffa458c1 DB |
879 | return -ENODEV; |
880 | } | |
881 | ||
882 | if (!pdata) { | |
2e5a7bd9 | 883 | dev_dbg(&spi->dev, "no platform data?\n"); |
ffa458c1 DB |
884 | return -ENODEV; |
885 | } | |
886 | ||
887 | /* don't exceed max specified sample rate */ | |
d93f70b2 | 888 | if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { |
2e5a7bd9 | 889 | dev_dbg(&spi->dev, "f(sample) %d KHz?\n", |
d93f70b2 | 890 | (spi->max_speed_hz/SAMPLE_BITS)/1000); |
ffa458c1 DB |
891 | return -EINVAL; |
892 | } | |
893 | ||
9084533e DB |
894 | /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except |
895 | * that even if the hardware can do that, the SPI controller driver | |
896 | * may not. So we stick to very-portable 8 bit words, both RX and TX. | |
ffa458c1 | 897 | */ |
9084533e | 898 | spi->bits_per_word = 8; |
230ffc8e | 899 | spi->mode = SPI_MODE_0; |
7937e86a ID |
900 | err = spi_setup(spi); |
901 | if (err < 0) | |
902 | return err; | |
ffa458c1 | 903 | |
a90f7e98 | 904 | ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); |
e8f462d2 | 905 | packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); |
a90f7e98 | 906 | input_dev = input_allocate_device(); |
e8f462d2 | 907 | if (!ts || !packet || !input_dev) { |
a90f7e98 DT |
908 | err = -ENOMEM; |
909 | goto err_free_mem; | |
910 | } | |
ffa458c1 | 911 | |
2e5a7bd9 | 912 | dev_set_drvdata(&spi->dev, ts); |
ffa458c1 | 913 | |
e8f462d2 | 914 | ts->packet = packet; |
ffa458c1 | 915 | ts->spi = spi; |
a90f7e98 | 916 | ts->input = input_dev; |
7c6d0ee1 | 917 | ts->vref_mv = pdata->vref_mv; |
86579a4c | 918 | ts->swap_xy = pdata->swap_xy; |
ffa458c1 | 919 | |
c9cb2e3d | 920 | hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
ffa458c1 DB |
921 | ts->timer.function = ads7846_timer; |
922 | ||
7de90a8c ID |
923 | spin_lock_init(&ts->lock); |
924 | ||
ffa458c1 DB |
925 | ts->model = pdata->model ? : 7846; |
926 | ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; | |
927 | ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; | |
d5b415c9 | 928 | ts->pressure_max = pdata->pressure_max ? : ~0; |
da970e69 ID |
929 | |
930 | if (pdata->filter != NULL) { | |
931 | if (pdata->filter_init != NULL) { | |
932 | err = pdata->filter_init(pdata, &ts->filter_data); | |
933 | if (err < 0) | |
934 | goto err_free_mem; | |
935 | } | |
936 | ts->filter = pdata->filter; | |
937 | ts->filter_cleanup = pdata->filter_cleanup; | |
938 | } else if (pdata->debounce_max) { | |
d5b415c9 | 939 | ts->debounce_max = pdata->debounce_max; |
da970e69 ID |
940 | if (ts->debounce_max < 2) |
941 | ts->debounce_max = 2; | |
d5b415c9 ID |
942 | ts->debounce_tol = pdata->debounce_tol; |
943 | ts->debounce_rep = pdata->debounce_rep; | |
da970e69 ID |
944 | ts->filter = ads7846_debounce; |
945 | ts->filter_data = ts; | |
d5b415c9 | 946 | } else |
da970e69 | 947 | ts->filter = ads7846_no_filter; |
4d5975e5 EM |
948 | |
949 | err = setup_pendown(spi, ts); | |
950 | if (err) | |
951 | goto err_cleanup_filter; | |
ffa458c1 | 952 | |
1d25891f SH |
953 | if (pdata->penirq_recheck_delay_usecs) |
954 | ts->penirq_recheck_delay_usecs = | |
955 | pdata->penirq_recheck_delay_usecs; | |
956 | ||
fd746d54 EM |
957 | ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; |
958 | ||
a6c2490f | 959 | snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); |
b58895f8 | 960 | snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); |
ffa458c1 | 961 | |
b58895f8 | 962 | input_dev->name = ts->name; |
a90f7e98 | 963 | input_dev->phys = ts->phys; |
a5394fb0 | 964 | input_dev->dev.parent = &spi->dev; |
ffa458c1 | 965 | |
7b19ada2 JS |
966 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
967 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); | |
a90f7e98 | 968 | input_set_abs_params(input_dev, ABS_X, |
ffa458c1 DB |
969 | pdata->x_min ? : 0, |
970 | pdata->x_max ? : MAX_12BIT, | |
971 | 0, 0); | |
a90f7e98 | 972 | input_set_abs_params(input_dev, ABS_Y, |
ffa458c1 DB |
973 | pdata->y_min ? : 0, |
974 | pdata->y_max ? : MAX_12BIT, | |
975 | 0, 0); | |
a90f7e98 | 976 | input_set_abs_params(input_dev, ABS_PRESSURE, |
ffa458c1 DB |
977 | pdata->pressure_min, pdata->pressure_max, 0, 0); |
978 | ||
de2defd9 ID |
979 | vref = pdata->keep_vref_on; |
980 | ||
ffa458c1 DB |
981 | /* set up the transfers to read touchscreen state; this assumes we |
982 | * use formula #2 for pressure, not #3. | |
983 | */ | |
0b7018aa | 984 | m = &ts->msg[0]; |
ffa458c1 DB |
985 | x = ts->xfer; |
986 | ||
0b7018aa ID |
987 | spi_message_init(m); |
988 | ||
ffa458c1 | 989 | /* y- still on; turn on only y+ (and ADC) */ |
e8f462d2 DT |
990 | packet->read_y = READ_Y(vref); |
991 | x->tx_buf = &packet->read_y; | |
ffa458c1 | 992 | x->len = 1; |
0b7018aa | 993 | spi_message_add_tail(x, m); |
d93f70b2 | 994 | |
ffa458c1 | 995 | x++; |
e8f462d2 | 996 | x->rx_buf = &packet->tc.y; |
ffa458c1 | 997 | x->len = 2; |
0b7018aa ID |
998 | spi_message_add_tail(x, m); |
999 | ||
e4f48861 SH |
1000 | /* the first sample after switching drivers can be low quality; |
1001 | * optionally discard it, using a second one after the signals | |
1002 | * have had enough time to stabilize. | |
1003 | */ | |
1004 | if (pdata->settle_delay_usecs) { | |
1005 | x->delay_usecs = pdata->settle_delay_usecs; | |
1006 | ||
1007 | x++; | |
e8f462d2 | 1008 | x->tx_buf = &packet->read_y; |
e4f48861 SH |
1009 | x->len = 1; |
1010 | spi_message_add_tail(x, m); | |
1011 | ||
1012 | x++; | |
e8f462d2 | 1013 | x->rx_buf = &packet->tc.y; |
e4f48861 SH |
1014 | x->len = 2; |
1015 | spi_message_add_tail(x, m); | |
1016 | } | |
1017 | ||
da970e69 | 1018 | m->complete = ads7846_rx_val; |
0b7018aa ID |
1019 | m->context = ts; |
1020 | ||
1021 | m++; | |
1022 | spi_message_init(m); | |
1023 | ||
1024 | /* turn y- off, x+ on, then leave in lowpower */ | |
1025 | x++; | |
e8f462d2 DT |
1026 | packet->read_x = READ_X(vref); |
1027 | x->tx_buf = &packet->read_x; | |
0b7018aa ID |
1028 | x->len = 1; |
1029 | spi_message_add_tail(x, m); | |
1030 | ||
1031 | x++; | |
e8f462d2 | 1032 | x->rx_buf = &packet->tc.x; |
0b7018aa ID |
1033 | x->len = 2; |
1034 | spi_message_add_tail(x, m); | |
1035 | ||
e4f48861 SH |
1036 | /* ... maybe discard first sample ... */ |
1037 | if (pdata->settle_delay_usecs) { | |
1038 | x->delay_usecs = pdata->settle_delay_usecs; | |
1039 | ||
1040 | x++; | |
e8f462d2 | 1041 | x->tx_buf = &packet->read_x; |
e4f48861 SH |
1042 | x->len = 1; |
1043 | spi_message_add_tail(x, m); | |
1044 | ||
1045 | x++; | |
e8f462d2 | 1046 | x->rx_buf = &packet->tc.x; |
e4f48861 SH |
1047 | x->len = 2; |
1048 | spi_message_add_tail(x, m); | |
1049 | } | |
1050 | ||
da970e69 | 1051 | m->complete = ads7846_rx_val; |
0b7018aa | 1052 | m->context = ts; |
ffa458c1 DB |
1053 | |
1054 | /* turn y+ off, x- on; we'll use formula #2 */ | |
1055 | if (ts->model == 7846) { | |
0b7018aa ID |
1056 | m++; |
1057 | spi_message_init(m); | |
1058 | ||
d93f70b2 | 1059 | x++; |
e8f462d2 DT |
1060 | packet->read_z1 = READ_Z1(vref); |
1061 | x->tx_buf = &packet->read_z1; | |
ffa458c1 | 1062 | x->len = 1; |
0b7018aa | 1063 | spi_message_add_tail(x, m); |
d93f70b2 | 1064 | |
ffa458c1 | 1065 | x++; |
e8f462d2 | 1066 | x->rx_buf = &packet->tc.z1; |
ffa458c1 | 1067 | x->len = 2; |
0b7018aa ID |
1068 | spi_message_add_tail(x, m); |
1069 | ||
e4f48861 SH |
1070 | /* ... maybe discard first sample ... */ |
1071 | if (pdata->settle_delay_usecs) { | |
1072 | x->delay_usecs = pdata->settle_delay_usecs; | |
1073 | ||
1074 | x++; | |
e8f462d2 | 1075 | x->tx_buf = &packet->read_z1; |
e4f48861 SH |
1076 | x->len = 1; |
1077 | spi_message_add_tail(x, m); | |
1078 | ||
1079 | x++; | |
e8f462d2 | 1080 | x->rx_buf = &packet->tc.z1; |
e4f48861 SH |
1081 | x->len = 2; |
1082 | spi_message_add_tail(x, m); | |
1083 | } | |
1084 | ||
da970e69 | 1085 | m->complete = ads7846_rx_val; |
0b7018aa ID |
1086 | m->context = ts; |
1087 | ||
1088 | m++; | |
1089 | spi_message_init(m); | |
ffa458c1 | 1090 | |
d93f70b2 | 1091 | x++; |
e8f462d2 DT |
1092 | packet->read_z2 = READ_Z2(vref); |
1093 | x->tx_buf = &packet->read_z2; | |
ffa458c1 | 1094 | x->len = 1; |
0b7018aa | 1095 | spi_message_add_tail(x, m); |
d93f70b2 | 1096 | |
ffa458c1 | 1097 | x++; |
e8f462d2 | 1098 | x->rx_buf = &packet->tc.z2; |
ffa458c1 | 1099 | x->len = 2; |
0b7018aa | 1100 | spi_message_add_tail(x, m); |
ffa458c1 | 1101 | |
e4f48861 SH |
1102 | /* ... maybe discard first sample ... */ |
1103 | if (pdata->settle_delay_usecs) { | |
1104 | x->delay_usecs = pdata->settle_delay_usecs; | |
1105 | ||
1106 | x++; | |
e8f462d2 | 1107 | x->tx_buf = &packet->read_z2; |
e4f48861 SH |
1108 | x->len = 1; |
1109 | spi_message_add_tail(x, m); | |
1110 | ||
1111 | x++; | |
e8f462d2 | 1112 | x->rx_buf = &packet->tc.z2; |
e4f48861 SH |
1113 | x->len = 2; |
1114 | spi_message_add_tail(x, m); | |
1115 | } | |
1116 | ||
da970e69 | 1117 | m->complete = ads7846_rx_val; |
0b7018aa ID |
1118 | m->context = ts; |
1119 | } | |
53a0ef89 ID |
1120 | |
1121 | /* power down */ | |
0b7018aa ID |
1122 | m++; |
1123 | spi_message_init(m); | |
1124 | ||
53a0ef89 | 1125 | x++; |
e8f462d2 DT |
1126 | packet->pwrdown = PWRDOWN; |
1127 | x->tx_buf = &packet->pwrdown; | |
53a0ef89 | 1128 | x->len = 1; |
0b7018aa | 1129 | spi_message_add_tail(x, m); |
53a0ef89 ID |
1130 | |
1131 | x++; | |
e8f462d2 | 1132 | x->rx_buf = &packet->dummy; |
53a0ef89 | 1133 | x->len = 2; |
d93f70b2 | 1134 | CS_CHANGE(*x); |
0b7018aa | 1135 | spi_message_add_tail(x, m); |
ffa458c1 | 1136 | |
0b7018aa ID |
1137 | m->complete = ads7846_rx; |
1138 | m->context = ts; | |
ffa458c1 | 1139 | |
d5b415c9 ID |
1140 | ts->last_msg = m; |
1141 | ||
dace1453 | 1142 | if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING, |
9084533e | 1143 | spi->dev.driver->name, ts)) { |
c57c0a2a MR |
1144 | dev_info(&spi->dev, |
1145 | "trying pin change workaround on irq %d\n", spi->irq); | |
1146 | err = request_irq(spi->irq, ads7846_irq, | |
1147 | IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, | |
1148 | spi->dev.driver->name, ts); | |
1149 | if (err) { | |
1150 | dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); | |
1151 | goto err_free_gpio; | |
1152 | } | |
ffa458c1 | 1153 | } |
ffa458c1 | 1154 | |
2c8dc071 DB |
1155 | err = ads784x_hwmon_register(spi, ts); |
1156 | if (err) | |
1157 | goto err_free_irq; | |
1158 | ||
2e5a7bd9 | 1159 | dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); |
ffa458c1 | 1160 | |
2c8dc071 | 1161 | /* take a first sample, leaving nPENIRQ active and vREF off; avoid |
ffa458c1 DB |
1162 | * the touchscreen, in case it's not connected. |
1163 | */ | |
2e5a7bd9 | 1164 | (void) ads7846_read12_ser(&spi->dev, |
ffa458c1 DB |
1165 | READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON); |
1166 | ||
2c8dc071 | 1167 | err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); |
8dd51650 | 1168 | if (err) |
2c8dc071 | 1169 | goto err_remove_hwmon; |
7de90a8c | 1170 | |
a90f7e98 DT |
1171 | err = input_register_device(input_dev); |
1172 | if (err) | |
8dd51650 | 1173 | goto err_remove_attr_group; |
a90f7e98 | 1174 | |
ffa458c1 | 1175 | return 0; |
a90f7e98 | 1176 | |
8dd51650 | 1177 | err_remove_attr_group: |
2c8dc071 DB |
1178 | sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); |
1179 | err_remove_hwmon: | |
1180 | ads784x_hwmon_unregister(spi, ts); | |
8dd51650 | 1181 | err_free_irq: |
a90f7e98 | 1182 | free_irq(spi->irq, ts); |
4d5975e5 EM |
1183 | err_free_gpio: |
1184 | if (ts->gpio_pendown != -1) | |
1185 | gpio_free(ts->gpio_pendown); | |
da970e69 ID |
1186 | err_cleanup_filter: |
1187 | if (ts->filter_cleanup) | |
1188 | ts->filter_cleanup(ts->filter_data); | |
a90f7e98 DT |
1189 | err_free_mem: |
1190 | input_free_device(input_dev); | |
e8f462d2 | 1191 | kfree(packet); |
a90f7e98 DT |
1192 | kfree(ts); |
1193 | return err; | |
ffa458c1 DB |
1194 | } |
1195 | ||
2e5a7bd9 | 1196 | static int __devexit ads7846_remove(struct spi_device *spi) |
ffa458c1 | 1197 | { |
2e5a7bd9 | 1198 | struct ads7846 *ts = dev_get_drvdata(&spi->dev); |
ffa458c1 | 1199 | |
2c8dc071 | 1200 | ads784x_hwmon_unregister(spi, ts); |
7de90a8c ID |
1201 | input_unregister_device(ts->input); |
1202 | ||
2e5a7bd9 | 1203 | ads7846_suspend(spi, PMSG_SUSPEND); |
ffa458c1 | 1204 | |
2c8dc071 | 1205 | sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); |
ffa458c1 | 1206 | |
7de90a8c | 1207 | free_irq(ts->spi->irq, ts); |
c9e617a5 ID |
1208 | /* suspend left the IRQ disabled */ |
1209 | enable_irq(ts->spi->irq); | |
7de90a8c | 1210 | |
4d5975e5 EM |
1211 | if (ts->gpio_pendown != -1) |
1212 | gpio_free(ts->gpio_pendown); | |
1213 | ||
da970e69 ID |
1214 | if (ts->filter_cleanup) |
1215 | ts->filter_cleanup(ts->filter_data); | |
1216 | ||
e8f462d2 | 1217 | kfree(ts->packet); |
ffa458c1 DB |
1218 | kfree(ts); |
1219 | ||
2e5a7bd9 | 1220 | dev_dbg(&spi->dev, "unregistered touchscreen\n"); |
ffa458c1 DB |
1221 | return 0; |
1222 | } | |
1223 | ||
2e5a7bd9 DB |
1224 | static struct spi_driver ads7846_driver = { |
1225 | .driver = { | |
1226 | .name = "ads7846", | |
1227 | .bus = &spi_bus_type, | |
1228 | .owner = THIS_MODULE, | |
1229 | }, | |
ffa458c1 | 1230 | .probe = ads7846_probe, |
2e5a7bd9 | 1231 | .remove = __devexit_p(ads7846_remove), |
ffa458c1 DB |
1232 | .suspend = ads7846_suspend, |
1233 | .resume = ads7846_resume, | |
1234 | }; | |
1235 | ||
1236 | static int __init ads7846_init(void) | |
1237 | { | |
2e5a7bd9 | 1238 | return spi_register_driver(&ads7846_driver); |
ffa458c1 DB |
1239 | } |
1240 | module_init(ads7846_init); | |
1241 | ||
1242 | static void __exit ads7846_exit(void) | |
1243 | { | |
2e5a7bd9 | 1244 | spi_unregister_driver(&ads7846_driver); |
ffa458c1 DB |
1245 | } |
1246 | module_exit(ads7846_exit); | |
1247 | ||
1248 | MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); | |
1249 | MODULE_LICENSE("GPL"); | |
e0626e38 | 1250 | MODULE_ALIAS("spi:ads7846"); |