xref: /linux/drivers/input/keyboard/lm8323.c (revision e814f3fd16acfb7f9966773953de8f740a1e3202)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * drivers/i2c/chips/lm8323.c
4  *
5  * Copyright (C) 2007-2009 Nokia Corporation
6  *
7  * Written by Daniel Stone <daniel.stone@nokia.com>
8  *            Timo O. Karjalainen <timo.o.karjalainen@nokia.com>
9  *
10  * Updated by Felipe Balbi <felipe.balbi@nokia.com>
11  */
12 
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/interrupt.h>
16 #include <linux/sched.h>
17 #include <linux/mutex.h>
18 #include <linux/delay.h>
19 #include <linux/input.h>
20 #include <linux/leds.h>
21 #include <linux/platform_data/lm8323.h>
22 #include <linux/pm.h>
23 #include <linux/slab.h>
24 #include <linux/string_choices.h>
25 
26 /* Commands to send to the chip. */
27 #define LM8323_CMD_READ_ID		0x80 /* Read chip ID. */
28 #define LM8323_CMD_WRITE_CFG		0x81 /* Set configuration item. */
29 #define LM8323_CMD_READ_INT		0x82 /* Get interrupt status. */
30 #define LM8323_CMD_RESET		0x83 /* Reset, same as external one */
31 #define LM8323_CMD_WRITE_PORT_SEL	0x85 /* Set GPIO in/out. */
32 #define LM8323_CMD_WRITE_PORT_STATE	0x86 /* Set GPIO pullup. */
33 #define LM8323_CMD_READ_PORT_SEL	0x87 /* Get GPIO in/out. */
34 #define LM8323_CMD_READ_PORT_STATE	0x88 /* Get GPIO pullup. */
35 #define LM8323_CMD_READ_FIFO		0x89 /* Read byte from FIFO. */
36 #define LM8323_CMD_RPT_READ_FIFO	0x8a /* Read FIFO (no increment). */
37 #define LM8323_CMD_SET_ACTIVE		0x8b /* Set active time. */
38 #define LM8323_CMD_READ_ERR		0x8c /* Get error status. */
39 #define LM8323_CMD_READ_ROTATOR		0x8e /* Read rotator status. */
40 #define LM8323_CMD_SET_DEBOUNCE		0x8f /* Set debouncing time. */
41 #define LM8323_CMD_SET_KEY_SIZE		0x90 /* Set keypad size. */
42 #define LM8323_CMD_READ_KEY_SIZE	0x91 /* Get keypad size. */
43 #define LM8323_CMD_READ_CFG		0x92 /* Get configuration item. */
44 #define LM8323_CMD_WRITE_CLOCK		0x93 /* Set clock config. */
45 #define LM8323_CMD_READ_CLOCK		0x94 /* Get clock config. */
46 #define LM8323_CMD_PWM_WRITE		0x95 /* Write PWM script. */
47 #define LM8323_CMD_START_PWM		0x96 /* Start PWM engine. */
48 #define LM8323_CMD_STOP_PWM		0x97 /* Stop PWM engine. */
49 
50 /* Interrupt status. */
51 #define INT_KEYPAD			0x01 /* Key event. */
52 #define INT_ROTATOR			0x02 /* Rotator event. */
53 #define INT_ERROR			0x08 /* Error: use CMD_READ_ERR. */
54 #define INT_NOINIT			0x10 /* Lost configuration. */
55 #define INT_PWM1			0x20 /* PWM1 stopped. */
56 #define INT_PWM2			0x40 /* PWM2 stopped. */
57 #define INT_PWM3			0x80 /* PWM3 stopped. */
58 
59 /* Errors (signalled by INT_ERROR, read with CMD_READ_ERR). */
60 #define ERR_BADPAR			0x01 /* Bad parameter. */
61 #define ERR_CMDUNK			0x02 /* Unknown command. */
62 #define ERR_KEYOVR			0x04 /* Too many keys pressed. */
63 #define ERR_FIFOOVER			0x40 /* FIFO overflow. */
64 
65 /* Configuration keys (CMD_{WRITE,READ}_CFG). */
66 #define CFG_MUX1SEL			0x01 /* Select MUX1_OUT input. */
67 #define CFG_MUX1EN			0x02 /* Enable MUX1_OUT. */
68 #define CFG_MUX2SEL			0x04 /* Select MUX2_OUT input. */
69 #define CFG_MUX2EN			0x08 /* Enable MUX2_OUT. */
70 #define CFG_PSIZE			0x20 /* Package size (must be 0). */
71 #define CFG_ROTEN			0x40 /* Enable rotator. */
72 
73 /* Clock settings (CMD_{WRITE,READ}_CLOCK). */
74 #define CLK_RCPWM_INTERNAL		0x00
75 #define CLK_RCPWM_EXTERNAL		0x03
76 #define CLK_SLOWCLKEN			0x08 /* Enable 32.768kHz clock. */
77 #define CLK_SLOWCLKOUT			0x40 /* Enable slow pulse output. */
78 
79 /* The possible addresses corresponding to CONFIG1 and CONFIG2 pin wirings. */
80 #define LM8323_I2C_ADDR00		(0x84 >> 1)	/* 1000 010x */
81 #define LM8323_I2C_ADDR01		(0x86 >> 1)	/* 1000 011x */
82 #define LM8323_I2C_ADDR10		(0x88 >> 1)	/* 1000 100x */
83 #define LM8323_I2C_ADDR11		(0x8A >> 1)	/* 1000 101x */
84 
85 /* Key event fifo length */
86 #define LM8323_FIFO_LEN			15
87 
88 /* Commands for PWM engine; feed in with PWM_WRITE. */
89 /* Load ramp counter from duty cycle field (range 0 - 0xff). */
90 #define PWM_SET(v)			(0x4000 | ((v) & 0xff))
91 /* Go to start of script. */
92 #define PWM_GOTOSTART			0x0000
93 /*
94  * Stop engine (generates interrupt).  If reset is 1, clear the program
95  * counter, else leave it.
96  */
97 #define PWM_END(reset)			(0xc000 | (!!(reset) << 11))
98 /*
99  * Ramp.  If s is 1, divide clock by 512, else divide clock by 16.
100  * Take t clock scales (up to 63) per step, for n steps (up to 126).
101  * If u is set, ramp up, else ramp down.
102  */
103 #define PWM_RAMP(s, t, n, u)		((!!(s) << 14) | ((t) & 0x3f) << 8 | \
104 					 ((n) & 0x7f) | ((u) ? 0 : 0x80))
105 /*
106  * Loop (i.e. jump back to pos) for a given number of iterations (up to 63).
107  * If cnt is zero, execute until PWM_END is encountered.
108  */
109 #define PWM_LOOP(cnt, pos)		(0xa000 | (((cnt) & 0x3f) << 7) | \
110 					 ((pos) & 0x3f))
111 /*
112  * Wait for trigger.  Argument is a mask of channels, shifted by the channel
113  * number, e.g. 0xa for channels 3 and 1.  Note that channels are numbered
114  * from 1, not 0.
115  */
116 #define PWM_WAIT_TRIG(chans)		(0xe000 | (((chans) & 0x7) << 6))
117 /* Send trigger.  Argument is same as PWM_WAIT_TRIG. */
118 #define PWM_SEND_TRIG(chans)		(0xe000 | ((chans) & 0x7))
119 
120 struct lm8323_pwm {
121 	int			id;
122 	int			fade_time;
123 	int			brightness;
124 	int			desired_brightness;
125 	bool			enabled;
126 	bool			running;
127 	/* pwm lock */
128 	struct mutex		lock;
129 	struct work_struct	work;
130 	struct led_classdev	cdev;
131 	struct lm8323_chip	*chip;
132 };
133 
134 struct lm8323_chip {
135 	/* device lock */
136 	struct mutex		lock;
137 	struct i2c_client	*client;
138 	struct input_dev	*idev;
139 	bool			kp_enabled;
140 	bool			pm_suspend;
141 	unsigned		keys_down;
142 	char			phys[32];
143 	unsigned short		keymap[LM8323_KEYMAP_SIZE];
144 	int			size_x;
145 	int			size_y;
146 	int			debounce_time;
147 	int			active_time;
148 	struct lm8323_pwm	pwm[LM8323_NUM_PWMS];
149 };
150 
151 #define client_to_lm8323(c)	container_of(c, struct lm8323_chip, client)
152 #define dev_to_lm8323(d)	container_of(d, struct lm8323_chip, client->dev)
153 #define cdev_to_pwm(c)		container_of(c, struct lm8323_pwm, cdev)
154 #define work_to_pwm(w)		container_of(w, struct lm8323_pwm, work)
155 
156 #define LM8323_MAX_DATA 8
157 
158 /*
159  * To write, we just access the chip's address in write mode, and dump the
160  * command and data out on the bus.  The command byte and data are taken as
161  * sequential u8s out of varargs, to a maximum of LM8323_MAX_DATA.
162  */
163 static int lm8323_write(struct lm8323_chip *lm, int len, ...)
164 {
165 	int ret, i;
166 	va_list ap;
167 	u8 data[LM8323_MAX_DATA];
168 
169 	va_start(ap, len);
170 
171 	if (unlikely(len > LM8323_MAX_DATA)) {
172 		dev_err(&lm->client->dev, "tried to send %d bytes\n", len);
173 		va_end(ap);
174 		return 0;
175 	}
176 
177 	for (i = 0; i < len; i++)
178 		data[i] = va_arg(ap, int);
179 
180 	va_end(ap);
181 
182 	/*
183 	 * If the host is asleep while we send the data, we can get a NACK
184 	 * back while it wakes up, so try again, once.
185 	 */
186 	ret = i2c_master_send(lm->client, data, len);
187 	if (unlikely(ret == -EREMOTEIO))
188 		ret = i2c_master_send(lm->client, data, len);
189 	if (unlikely(ret != len))
190 		dev_err(&lm->client->dev, "sent %d bytes of %d total\n",
191 			len, ret);
192 
193 	return ret;
194 }
195 
196 /*
197  * To read, we first send the command byte to the chip and end the transaction,
198  * then access the chip in read mode, at which point it will send the data.
199  */
200 static int lm8323_read(struct lm8323_chip *lm, u8 cmd, u8 *buf, int len)
201 {
202 	int ret;
203 
204 	/*
205 	 * If the host is asleep while we send the byte, we can get a NACK
206 	 * back while it wakes up, so try again, once.
207 	 */
208 	ret = i2c_master_send(lm->client, &cmd, 1);
209 	if (unlikely(ret == -EREMOTEIO))
210 		ret = i2c_master_send(lm->client, &cmd, 1);
211 	if (unlikely(ret != 1)) {
212 		dev_err(&lm->client->dev, "sending read cmd 0x%02x failed\n",
213 			cmd);
214 		return 0;
215 	}
216 
217 	ret = i2c_master_recv(lm->client, buf, len);
218 	if (unlikely(ret != len))
219 		dev_err(&lm->client->dev, "wanted %d bytes, got %d\n",
220 			len, ret);
221 
222 	return ret;
223 }
224 
225 /*
226  * Set the chip active time (idle time before it enters halt).
227  */
228 static void lm8323_set_active_time(struct lm8323_chip *lm, int time)
229 {
230 	lm8323_write(lm, 2, LM8323_CMD_SET_ACTIVE, time >> 2);
231 }
232 
233 /*
234  * The signals are AT-style: the low 7 bits are the keycode, and the top
235  * bit indicates the state (1 for down, 0 for up).
236  */
237 static inline u8 lm8323_whichkey(u8 event)
238 {
239 	return event & 0x7f;
240 }
241 
242 static inline int lm8323_ispress(u8 event)
243 {
244 	return (event & 0x80) ? 1 : 0;
245 }
246 
247 static void process_keys(struct lm8323_chip *lm)
248 {
249 	u8 event;
250 	u8 key_fifo[LM8323_FIFO_LEN + 1];
251 	int old_keys_down = lm->keys_down;
252 	int ret;
253 	int i = 0;
254 
255 	/*
256 	 * Read all key events from the FIFO at once. Next READ_FIFO clears the
257 	 * FIFO even if we didn't read all events previously.
258 	 */
259 	ret = lm8323_read(lm, LM8323_CMD_READ_FIFO, key_fifo, LM8323_FIFO_LEN);
260 
261 	if (ret < 0) {
262 		dev_err(&lm->client->dev, "Failed reading fifo \n");
263 		return;
264 	}
265 	key_fifo[ret] = 0;
266 
267 	while ((event = key_fifo[i++])) {
268 		u8 key = lm8323_whichkey(event);
269 		int isdown = lm8323_ispress(event);
270 		unsigned short keycode = lm->keymap[key];
271 
272 		dev_vdbg(&lm->client->dev, "key 0x%02x %s\n",
273 			 key, str_down_up(isdown));
274 
275 		if (lm->kp_enabled) {
276 			input_event(lm->idev, EV_MSC, MSC_SCAN, key);
277 			input_report_key(lm->idev, keycode, isdown);
278 			input_sync(lm->idev);
279 		}
280 
281 		if (isdown)
282 			lm->keys_down++;
283 		else
284 			lm->keys_down--;
285 	}
286 
287 	/*
288 	 * Errata: We need to ensure that the chip never enters halt mode
289 	 * during a keypress, so set active time to 0.  When it's released,
290 	 * we can enter halt again, so set the active time back to normal.
291 	 */
292 	if (!old_keys_down && lm->keys_down)
293 		lm8323_set_active_time(lm, 0);
294 	if (old_keys_down && !lm->keys_down)
295 		lm8323_set_active_time(lm, lm->active_time);
296 }
297 
298 static void lm8323_process_error(struct lm8323_chip *lm)
299 {
300 	u8 error;
301 
302 	if (lm8323_read(lm, LM8323_CMD_READ_ERR, &error, 1) == 1) {
303 		if (error & ERR_FIFOOVER)
304 			dev_vdbg(&lm->client->dev, "fifo overflow!\n");
305 		if (error & ERR_KEYOVR)
306 			dev_vdbg(&lm->client->dev,
307 					"more than two keys pressed\n");
308 		if (error & ERR_CMDUNK)
309 			dev_vdbg(&lm->client->dev,
310 					"unknown command submitted\n");
311 		if (error & ERR_BADPAR)
312 			dev_vdbg(&lm->client->dev, "bad command parameter\n");
313 	}
314 }
315 
316 static void lm8323_reset(struct lm8323_chip *lm)
317 {
318 	/* The docs say we must pass 0xAA as the data byte. */
319 	lm8323_write(lm, 2, LM8323_CMD_RESET, 0xAA);
320 }
321 
322 static int lm8323_configure(struct lm8323_chip *lm)
323 {
324 	int keysize = (lm->size_x << 4) | lm->size_y;
325 	int clock = (CLK_SLOWCLKEN | CLK_RCPWM_EXTERNAL);
326 	int debounce = lm->debounce_time >> 2;
327 	int active = lm->active_time >> 2;
328 
329 	/*
330 	 * Active time must be greater than the debounce time: if it's
331 	 * a close-run thing, give ourselves a 12ms buffer.
332 	 */
333 	if (debounce >= active)
334 		active = debounce + 3;
335 
336 	lm8323_write(lm, 2, LM8323_CMD_WRITE_CFG, 0);
337 	lm8323_write(lm, 2, LM8323_CMD_WRITE_CLOCK, clock);
338 	lm8323_write(lm, 2, LM8323_CMD_SET_KEY_SIZE, keysize);
339 	lm8323_set_active_time(lm, lm->active_time);
340 	lm8323_write(lm, 2, LM8323_CMD_SET_DEBOUNCE, debounce);
341 	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_STATE, 0xff, 0xff);
342 	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_SEL, 0, 0);
343 
344 	/*
345 	 * Not much we can do about errors at this point, so just hope
346 	 * for the best.
347 	 */
348 
349 	return 0;
350 }
351 
352 static void pwm_done(struct lm8323_pwm *pwm)
353 {
354 	guard(mutex)(&pwm->lock);
355 
356 	pwm->running = false;
357 	if (pwm->desired_brightness != pwm->brightness)
358 		schedule_work(&pwm->work);
359 }
360 
361 /*
362  * Bottom half: handle the interrupt by posting key events, or dealing with
363  * errors appropriately.
364  */
365 static irqreturn_t lm8323_irq(int irq, void *_lm)
366 {
367 	struct lm8323_chip *lm = _lm;
368 	u8 ints;
369 	int i;
370 
371 	guard(mutex)(&lm->lock);
372 
373 	while ((lm8323_read(lm, LM8323_CMD_READ_INT, &ints, 1) == 1) && ints) {
374 		if (likely(ints & INT_KEYPAD))
375 			process_keys(lm);
376 		if (ints & INT_ROTATOR) {
377 			/* We don't currently support the rotator. */
378 			dev_vdbg(&lm->client->dev, "rotator fired\n");
379 		}
380 		if (ints & INT_ERROR) {
381 			dev_vdbg(&lm->client->dev, "error!\n");
382 			lm8323_process_error(lm);
383 		}
384 		if (ints & INT_NOINIT) {
385 			dev_err(&lm->client->dev, "chip lost config; "
386 						  "reinitialising\n");
387 			lm8323_configure(lm);
388 		}
389 		for (i = 0; i < LM8323_NUM_PWMS; i++) {
390 			if (ints & (INT_PWM1 << i)) {
391 				dev_vdbg(&lm->client->dev,
392 					 "pwm%d engine completed\n", i);
393 				pwm_done(&lm->pwm[i]);
394 			}
395 		}
396 	}
397 
398 	return IRQ_HANDLED;
399 }
400 
401 /*
402  * Read the chip ID.
403  */
404 static int lm8323_read_id(struct lm8323_chip *lm, u8 *buf)
405 {
406 	int bytes;
407 
408 	bytes = lm8323_read(lm, LM8323_CMD_READ_ID, buf, 2);
409 	if (unlikely(bytes != 2))
410 		return -EIO;
411 
412 	return 0;
413 }
414 
415 static void lm8323_write_pwm_one(struct lm8323_pwm *pwm, int pos, u16 cmd)
416 {
417 	lm8323_write(pwm->chip, 4, LM8323_CMD_PWM_WRITE, (pos << 2) | pwm->id,
418 		     (cmd & 0xff00) >> 8, cmd & 0x00ff);
419 }
420 
421 /*
422  * Write a script into a given PWM engine, concluding with PWM_END.
423  * If 'kill' is nonzero, the engine will be shut down at the end
424  * of the script, producing a zero output. Otherwise the engine
425  * will be kept running at the final PWM level indefinitely.
426  */
427 static void lm8323_write_pwm(struct lm8323_pwm *pwm, int kill,
428 			     int len, const u16 *cmds)
429 {
430 	int i;
431 
432 	for (i = 0; i < len; i++)
433 		lm8323_write_pwm_one(pwm, i, cmds[i]);
434 
435 	lm8323_write_pwm_one(pwm, i++, PWM_END(kill));
436 	lm8323_write(pwm->chip, 2, LM8323_CMD_START_PWM, pwm->id);
437 	pwm->running = true;
438 }
439 
440 static void lm8323_pwm_work(struct work_struct *work)
441 {
442 	struct lm8323_pwm *pwm = work_to_pwm(work);
443 	int div512, perstep, steps, hz, up, kill;
444 	u16 pwm_cmds[3];
445 	int num_cmds = 0;
446 
447 	guard(mutex)(&pwm->lock);
448 
449 	/*
450 	 * Do nothing if we're already at the requested level,
451 	 * or previous setting is not yet complete. In the latter
452 	 * case we will be called again when the previous PWM script
453 	 * finishes.
454 	 */
455 	if (pwm->running || pwm->desired_brightness == pwm->brightness)
456 		return;
457 
458 	kill = (pwm->desired_brightness == 0);
459 	up = (pwm->desired_brightness > pwm->brightness);
460 	steps = abs(pwm->desired_brightness - pwm->brightness);
461 
462 	/*
463 	 * Convert time (in ms) into a divisor (512 or 16 on a refclk of
464 	 * 32768Hz), and number of ticks per step.
465 	 */
466 	if ((pwm->fade_time / steps) > (32768 / 512)) {
467 		div512 = 1;
468 		hz = 32768 / 512;
469 	} else {
470 		div512 = 0;
471 		hz = 32768 / 16;
472 	}
473 
474 	perstep = (hz * pwm->fade_time) / (steps * 1000);
475 
476 	if (perstep == 0)
477 		perstep = 1;
478 	else if (perstep > 63)
479 		perstep = 63;
480 
481 	while (steps) {
482 		int s;
483 
484 		s = min(126, steps);
485 		pwm_cmds[num_cmds++] = PWM_RAMP(div512, perstep, s, up);
486 		steps -= s;
487 	}
488 
489 	lm8323_write_pwm(pwm, kill, num_cmds, pwm_cmds);
490 	pwm->brightness = pwm->desired_brightness;
491 }
492 
493 static void lm8323_pwm_set_brightness(struct led_classdev *led_cdev,
494 				      enum led_brightness brightness)
495 {
496 	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
497 	struct lm8323_chip *lm = pwm->chip;
498 
499 	scoped_guard(mutex, &pwm->lock) {
500 		pwm->desired_brightness = brightness;
501 	}
502 
503 	if (in_interrupt()) {
504 		schedule_work(&pwm->work);
505 	} else {
506 		/*
507 		 * Schedule PWM work as usual unless we are going into suspend
508 		 */
509 		scoped_guard(mutex, &lm->lock) {
510 			if (likely(!lm->pm_suspend))
511 				schedule_work(&pwm->work);
512 			else
513 				lm8323_pwm_work(&pwm->work);
514 		}
515 	}
516 }
517 
518 static ssize_t lm8323_pwm_show_time(struct device *dev,
519 		struct device_attribute *attr, char *buf)
520 {
521 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
522 	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
523 
524 	return sprintf(buf, "%d\n", pwm->fade_time);
525 }
526 
527 static ssize_t lm8323_pwm_store_time(struct device *dev,
528 		struct device_attribute *attr, const char *buf, size_t len)
529 {
530 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
531 	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
532 	int ret, time;
533 
534 	ret = kstrtoint(buf, 10, &time);
535 	/* Numbers only, please. */
536 	if (ret)
537 		return ret;
538 
539 	pwm->fade_time = time;
540 
541 	return strlen(buf);
542 }
543 static DEVICE_ATTR(time, 0644, lm8323_pwm_show_time, lm8323_pwm_store_time);
544 
545 static struct attribute *lm8323_pwm_attrs[] = {
546 	&dev_attr_time.attr,
547 	NULL
548 };
549 ATTRIBUTE_GROUPS(lm8323_pwm);
550 
551 static int init_pwm(struct lm8323_chip *lm, int id, struct device *dev,
552 		    const char *name)
553 {
554 	struct lm8323_pwm *pwm;
555 	int err;
556 
557 	BUG_ON(id > 3);
558 
559 	pwm = &lm->pwm[id - 1];
560 
561 	pwm->id = id;
562 	pwm->fade_time = 0;
563 	pwm->brightness = 0;
564 	pwm->desired_brightness = 0;
565 	pwm->running = false;
566 	pwm->enabled = false;
567 	INIT_WORK(&pwm->work, lm8323_pwm_work);
568 	mutex_init(&pwm->lock);
569 	pwm->chip = lm;
570 
571 	if (name) {
572 		pwm->cdev.name = name;
573 		pwm->cdev.brightness_set = lm8323_pwm_set_brightness;
574 		pwm->cdev.groups = lm8323_pwm_groups;
575 
576 		err = devm_led_classdev_register(dev, &pwm->cdev);
577 		if (err) {
578 			dev_err(dev, "couldn't register PWM %d: %d\n", id, err);
579 			return err;
580 		}
581 		pwm->enabled = true;
582 	}
583 
584 	return 0;
585 }
586 
587 static ssize_t lm8323_show_disable(struct device *dev,
588 				   struct device_attribute *attr, char *buf)
589 {
590 	struct lm8323_chip *lm = dev_get_drvdata(dev);
591 
592 	return sprintf(buf, "%u\n", !lm->kp_enabled);
593 }
594 
595 static ssize_t lm8323_set_disable(struct device *dev,
596 				  struct device_attribute *attr,
597 				  const char *buf, size_t count)
598 {
599 	struct lm8323_chip *lm = dev_get_drvdata(dev);
600 	int ret;
601 	unsigned int i;
602 
603 	ret = kstrtouint(buf, 10, &i);
604 	if (ret)
605 		return ret;
606 
607 	guard(mutex)(&lm->lock);
608 
609 	lm->kp_enabled = !i;
610 
611 	return count;
612 }
613 static DEVICE_ATTR(disable_kp, 0644, lm8323_show_disable, lm8323_set_disable);
614 
615 static struct attribute *lm8323_attrs[] = {
616 	&dev_attr_disable_kp.attr,
617 	NULL,
618 };
619 ATTRIBUTE_GROUPS(lm8323);
620 
621 static int lm8323_probe(struct i2c_client *client)
622 {
623 	struct lm8323_platform_data *pdata = dev_get_platdata(&client->dev);
624 	struct input_dev *idev;
625 	struct lm8323_chip *lm;
626 	int pwm;
627 	int i, err;
628 	unsigned long tmo;
629 	u8 data[2];
630 
631 	if (!pdata || !pdata->size_x || !pdata->size_y) {
632 		dev_err(&client->dev, "missing platform_data\n");
633 		return -EINVAL;
634 	}
635 
636 	if (pdata->size_x > 8) {
637 		dev_err(&client->dev, "invalid x size %d specified\n",
638 			pdata->size_x);
639 		return -EINVAL;
640 	}
641 
642 	if (pdata->size_y > 12) {
643 		dev_err(&client->dev, "invalid y size %d specified\n",
644 			pdata->size_y);
645 		return -EINVAL;
646 	}
647 
648 	lm = devm_kzalloc(&client->dev, sizeof(*lm), GFP_KERNEL);
649 	if (!lm)
650 		return -ENOMEM;
651 
652 	idev = devm_input_allocate_device(&client->dev);
653 	if (!idev)
654 		return -ENOMEM;
655 
656 	lm->client = client;
657 	lm->idev = idev;
658 	mutex_init(&lm->lock);
659 
660 	lm->size_x = pdata->size_x;
661 	lm->size_y = pdata->size_y;
662 	dev_vdbg(&client->dev, "Keypad size: %d x %d\n",
663 		 lm->size_x, lm->size_y);
664 
665 	lm->debounce_time = pdata->debounce_time;
666 	lm->active_time = pdata->active_time;
667 
668 	lm8323_reset(lm);
669 
670 	/*
671 	 * Nothing's set up to service the IRQ yet, so just spin for max.
672 	 * 100ms until we can configure.
673 	 */
674 	tmo = jiffies + msecs_to_jiffies(100);
675 	while (lm8323_read(lm, LM8323_CMD_READ_INT, data, 1) == 1) {
676 		if (data[0] & INT_NOINIT)
677 			break;
678 
679 		if (time_after(jiffies, tmo)) {
680 			dev_err(&client->dev,
681 				"timeout waiting for initialisation\n");
682 			break;
683 		}
684 
685 		msleep(1);
686 	}
687 
688 	lm8323_configure(lm);
689 
690 	/* If a true probe check the device */
691 	if (lm8323_read_id(lm, data) != 0) {
692 		dev_err(&client->dev, "device not found\n");
693 		return -ENODEV;
694 	}
695 
696 	for (pwm = 0; pwm < LM8323_NUM_PWMS; pwm++) {
697 		err = init_pwm(lm, pwm + 1, &client->dev,
698 			       pdata->pwm_names[pwm]);
699 		if (err)
700 			return err;
701 	}
702 
703 	lm->kp_enabled = true;
704 
705 	idev->name = pdata->name ? : "LM8323 keypad";
706 	snprintf(lm->phys, sizeof(lm->phys),
707 		 "%s/input-kp", dev_name(&client->dev));
708 	idev->phys = lm->phys;
709 
710 	idev->evbit[0] = BIT(EV_KEY) | BIT(EV_MSC);
711 	__set_bit(MSC_SCAN, idev->mscbit);
712 	for (i = 0; i < LM8323_KEYMAP_SIZE; i++) {
713 		__set_bit(pdata->keymap[i], idev->keybit);
714 		lm->keymap[i] = pdata->keymap[i];
715 	}
716 	__clear_bit(KEY_RESERVED, idev->keybit);
717 
718 	if (pdata->repeat)
719 		__set_bit(EV_REP, idev->evbit);
720 
721 	err = input_register_device(idev);
722 	if (err) {
723 		dev_dbg(&client->dev, "error registering input device\n");
724 		return err;
725 	}
726 
727 	err = devm_request_threaded_irq(&client->dev, client->irq,
728 					NULL, lm8323_irq,
729 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
730 					"lm8323", lm);
731 	if (err) {
732 		dev_err(&client->dev, "could not get IRQ %d\n", client->irq);
733 		return err;
734 	}
735 
736 	i2c_set_clientdata(client, lm);
737 
738 	device_init_wakeup(&client->dev, 1);
739 	enable_irq_wake(client->irq);
740 
741 	return 0;
742 }
743 
744 /*
745  * We don't need to explicitly suspend the chip, as it already switches off
746  * when there's no activity.
747  */
748 static int lm8323_suspend(struct device *dev)
749 {
750 	struct i2c_client *client = to_i2c_client(dev);
751 	struct lm8323_chip *lm = i2c_get_clientdata(client);
752 	int i;
753 
754 	irq_set_irq_wake(client->irq, 0);
755 	disable_irq(client->irq);
756 
757 	scoped_guard(mutex, &lm->lock) {
758 		lm->pm_suspend = true;
759 	}
760 
761 	for (i = 0; i < 3; i++)
762 		if (lm->pwm[i].enabled)
763 			led_classdev_suspend(&lm->pwm[i].cdev);
764 
765 	return 0;
766 }
767 
768 static int lm8323_resume(struct device *dev)
769 {
770 	struct i2c_client *client = to_i2c_client(dev);
771 	struct lm8323_chip *lm = i2c_get_clientdata(client);
772 	int i;
773 
774 	scoped_guard(mutex, &lm->lock) {
775 		lm->pm_suspend = false;
776 	}
777 
778 	for (i = 0; i < 3; i++)
779 		if (lm->pwm[i].enabled)
780 			led_classdev_resume(&lm->pwm[i].cdev);
781 
782 	enable_irq(client->irq);
783 	irq_set_irq_wake(client->irq, 1);
784 
785 	return 0;
786 }
787 
788 static DEFINE_SIMPLE_DEV_PM_OPS(lm8323_pm_ops, lm8323_suspend, lm8323_resume);
789 
790 static const struct i2c_device_id lm8323_id[] = {
791 	{ "lm8323" },
792 	{ }
793 };
794 
795 static struct i2c_driver lm8323_i2c_driver = {
796 	.driver = {
797 		.name		= "lm8323",
798 		.pm		= pm_sleep_ptr(&lm8323_pm_ops),
799 		.dev_groups	= lm8323_groups,
800 	},
801 	.probe		= lm8323_probe,
802 	.id_table	= lm8323_id,
803 };
804 MODULE_DEVICE_TABLE(i2c, lm8323_id);
805 
806 module_i2c_driver(lm8323_i2c_driver);
807 
808 MODULE_AUTHOR("Timo O. Karjalainen <timo.o.karjalainen@nokia.com>");
809 MODULE_AUTHOR("Daniel Stone");
810 MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
811 MODULE_DESCRIPTION("LM8323 keypad driver");
812 MODULE_LICENSE("GPL");
813 
814