xref: /linux/drivers/input/keyboard/lm8323.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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 
25 /* Commands to send to the chip. */
26 #define LM8323_CMD_READ_ID		0x80 /* Read chip ID. */
27 #define LM8323_CMD_WRITE_CFG		0x81 /* Set configuration item. */
28 #define LM8323_CMD_READ_INT		0x82 /* Get interrupt status. */
29 #define LM8323_CMD_RESET		0x83 /* Reset, same as external one */
30 #define LM8323_CMD_WRITE_PORT_SEL	0x85 /* Set GPIO in/out. */
31 #define LM8323_CMD_WRITE_PORT_STATE	0x86 /* Set GPIO pullup. */
32 #define LM8323_CMD_READ_PORT_SEL	0x87 /* Get GPIO in/out. */
33 #define LM8323_CMD_READ_PORT_STATE	0x88 /* Get GPIO pullup. */
34 #define LM8323_CMD_READ_FIFO		0x89 /* Read byte from FIFO. */
35 #define LM8323_CMD_RPT_READ_FIFO	0x8a /* Read FIFO (no increment). */
36 #define LM8323_CMD_SET_ACTIVE		0x8b /* Set active time. */
37 #define LM8323_CMD_READ_ERR		0x8c /* Get error status. */
38 #define LM8323_CMD_READ_ROTATOR		0x8e /* Read rotator status. */
39 #define LM8323_CMD_SET_DEBOUNCE		0x8f /* Set debouncing time. */
40 #define LM8323_CMD_SET_KEY_SIZE		0x90 /* Set keypad size. */
41 #define LM8323_CMD_READ_KEY_SIZE	0x91 /* Get keypad size. */
42 #define LM8323_CMD_READ_CFG		0x92 /* Get configuration item. */
43 #define LM8323_CMD_WRITE_CLOCK		0x93 /* Set clock config. */
44 #define LM8323_CMD_READ_CLOCK		0x94 /* Get clock config. */
45 #define LM8323_CMD_PWM_WRITE		0x95 /* Write PWM script. */
46 #define LM8323_CMD_START_PWM		0x96 /* Start PWM engine. */
47 #define LM8323_CMD_STOP_PWM		0x97 /* Stop PWM engine. */
48 
49 /* Interrupt status. */
50 #define INT_KEYPAD			0x01 /* Key event. */
51 #define INT_ROTATOR			0x02 /* Rotator event. */
52 #define INT_ERROR			0x08 /* Error: use CMD_READ_ERR. */
53 #define INT_NOINIT			0x10 /* Lost configuration. */
54 #define INT_PWM1			0x20 /* PWM1 stopped. */
55 #define INT_PWM2			0x40 /* PWM2 stopped. */
56 #define INT_PWM3			0x80 /* PWM3 stopped. */
57 
58 /* Errors (signalled by INT_ERROR, read with CMD_READ_ERR). */
59 #define ERR_BADPAR			0x01 /* Bad parameter. */
60 #define ERR_CMDUNK			0x02 /* Unknown command. */
61 #define ERR_KEYOVR			0x04 /* Too many keys pressed. */
62 #define ERR_FIFOOVER			0x40 /* FIFO overflow. */
63 
64 /* Configuration keys (CMD_{WRITE,READ}_CFG). */
65 #define CFG_MUX1SEL			0x01 /* Select MUX1_OUT input. */
66 #define CFG_MUX1EN			0x02 /* Enable MUX1_OUT. */
67 #define CFG_MUX2SEL			0x04 /* Select MUX2_OUT input. */
68 #define CFG_MUX2EN			0x08 /* Enable MUX2_OUT. */
69 #define CFG_PSIZE			0x20 /* Package size (must be 0). */
70 #define CFG_ROTEN			0x40 /* Enable rotator. */
71 
72 /* Clock settings (CMD_{WRITE,READ}_CLOCK). */
73 #define CLK_RCPWM_INTERNAL		0x00
74 #define CLK_RCPWM_EXTERNAL		0x03
75 #define CLK_SLOWCLKEN			0x08 /* Enable 32.768kHz clock. */
76 #define CLK_SLOWCLKOUT			0x40 /* Enable slow pulse output. */
77 
78 /* The possible addresses corresponding to CONFIG1 and CONFIG2 pin wirings. */
79 #define LM8323_I2C_ADDR00		(0x84 >> 1)	/* 1000 010x */
80 #define LM8323_I2C_ADDR01		(0x86 >> 1)	/* 1000 011x */
81 #define LM8323_I2C_ADDR10		(0x88 >> 1)	/* 1000 100x */
82 #define LM8323_I2C_ADDR11		(0x8A >> 1)	/* 1000 101x */
83 
84 /* Key event fifo length */
85 #define LM8323_FIFO_LEN			15
86 
87 /* Commands for PWM engine; feed in with PWM_WRITE. */
88 /* Load ramp counter from duty cycle field (range 0 - 0xff). */
89 #define PWM_SET(v)			(0x4000 | ((v) & 0xff))
90 /* Go to start of script. */
91 #define PWM_GOTOSTART			0x0000
92 /*
93  * Stop engine (generates interrupt).  If reset is 1, clear the program
94  * counter, else leave it.
95  */
96 #define PWM_END(reset)			(0xc000 | (!!(reset) << 11))
97 /*
98  * Ramp.  If s is 1, divide clock by 512, else divide clock by 16.
99  * Take t clock scales (up to 63) per step, for n steps (up to 126).
100  * If u is set, ramp up, else ramp down.
101  */
102 #define PWM_RAMP(s, t, n, u)		((!!(s) << 14) | ((t) & 0x3f) << 8 | \
103 					 ((n) & 0x7f) | ((u) ? 0 : 0x80))
104 /*
105  * Loop (i.e. jump back to pos) for a given number of iterations (up to 63).
106  * If cnt is zero, execute until PWM_END is encountered.
107  */
108 #define PWM_LOOP(cnt, pos)		(0xa000 | (((cnt) & 0x3f) << 7) | \
109 					 ((pos) & 0x3f))
110 /*
111  * Wait for trigger.  Argument is a mask of channels, shifted by the channel
112  * number, e.g. 0xa for channels 3 and 1.  Note that channels are numbered
113  * from 1, not 0.
114  */
115 #define PWM_WAIT_TRIG(chans)		(0xe000 | (((chans) & 0x7) << 6))
116 /* Send trigger.  Argument is same as PWM_WAIT_TRIG. */
117 #define PWM_SEND_TRIG(chans)		(0xe000 | ((chans) & 0x7))
118 
119 struct lm8323_pwm {
120 	int			id;
121 	int			fade_time;
122 	int			brightness;
123 	int			desired_brightness;
124 	bool			enabled;
125 	bool			running;
126 	/* pwm lock */
127 	struct mutex		lock;
128 	struct work_struct	work;
129 	struct led_classdev	cdev;
130 	struct lm8323_chip	*chip;
131 };
132 
133 struct lm8323_chip {
134 	/* device lock */
135 	struct mutex		lock;
136 	struct i2c_client	*client;
137 	struct input_dev	*idev;
138 	bool			kp_enabled;
139 	bool			pm_suspend;
140 	unsigned		keys_down;
141 	char			phys[32];
142 	unsigned short		keymap[LM8323_KEYMAP_SIZE];
143 	int			size_x;
144 	int			size_y;
145 	int			debounce_time;
146 	int			active_time;
147 	struct lm8323_pwm	pwm[LM8323_NUM_PWMS];
148 };
149 
150 #define client_to_lm8323(c)	container_of(c, struct lm8323_chip, client)
151 #define dev_to_lm8323(d)	container_of(d, struct lm8323_chip, client->dev)
152 #define cdev_to_pwm(c)		container_of(c, struct lm8323_pwm, cdev)
153 #define work_to_pwm(w)		container_of(w, struct lm8323_pwm, work)
154 
155 #define LM8323_MAX_DATA 8
156 
157 /*
158  * To write, we just access the chip's address in write mode, and dump the
159  * command and data out on the bus.  The command byte and data are taken as
160  * sequential u8s out of varargs, to a maximum of LM8323_MAX_DATA.
161  */
162 static int lm8323_write(struct lm8323_chip *lm, int len, ...)
163 {
164 	int ret, i;
165 	va_list ap;
166 	u8 data[LM8323_MAX_DATA];
167 
168 	va_start(ap, len);
169 
170 	if (unlikely(len > LM8323_MAX_DATA)) {
171 		dev_err(&lm->client->dev, "tried to send %d bytes\n", len);
172 		va_end(ap);
173 		return 0;
174 	}
175 
176 	for (i = 0; i < len; i++)
177 		data[i] = va_arg(ap, int);
178 
179 	va_end(ap);
180 
181 	/*
182 	 * If the host is asleep while we send the data, we can get a NACK
183 	 * back while it wakes up, so try again, once.
184 	 */
185 	ret = i2c_master_send(lm->client, data, len);
186 	if (unlikely(ret == -EREMOTEIO))
187 		ret = i2c_master_send(lm->client, data, len);
188 	if (unlikely(ret != len))
189 		dev_err(&lm->client->dev, "sent %d bytes of %d total\n",
190 			len, ret);
191 
192 	return ret;
193 }
194 
195 /*
196  * To read, we first send the command byte to the chip and end the transaction,
197  * then access the chip in read mode, at which point it will send the data.
198  */
199 static int lm8323_read(struct lm8323_chip *lm, u8 cmd, u8 *buf, int len)
200 {
201 	int ret;
202 
203 	/*
204 	 * If the host is asleep while we send the byte, we can get a NACK
205 	 * back while it wakes up, so try again, once.
206 	 */
207 	ret = i2c_master_send(lm->client, &cmd, 1);
208 	if (unlikely(ret == -EREMOTEIO))
209 		ret = i2c_master_send(lm->client, &cmd, 1);
210 	if (unlikely(ret != 1)) {
211 		dev_err(&lm->client->dev, "sending read cmd 0x%02x failed\n",
212 			cmd);
213 		return 0;
214 	}
215 
216 	ret = i2c_master_recv(lm->client, buf, len);
217 	if (unlikely(ret != len))
218 		dev_err(&lm->client->dev, "wanted %d bytes, got %d\n",
219 			len, ret);
220 
221 	return ret;
222 }
223 
224 /*
225  * Set the chip active time (idle time before it enters halt).
226  */
227 static void lm8323_set_active_time(struct lm8323_chip *lm, int time)
228 {
229 	lm8323_write(lm, 2, LM8323_CMD_SET_ACTIVE, time >> 2);
230 }
231 
232 /*
233  * The signals are AT-style: the low 7 bits are the keycode, and the top
234  * bit indicates the state (1 for down, 0 for up).
235  */
236 static inline u8 lm8323_whichkey(u8 event)
237 {
238 	return event & 0x7f;
239 }
240 
241 static inline int lm8323_ispress(u8 event)
242 {
243 	return (event & 0x80) ? 1 : 0;
244 }
245 
246 static void process_keys(struct lm8323_chip *lm)
247 {
248 	u8 event;
249 	u8 key_fifo[LM8323_FIFO_LEN + 1];
250 	int old_keys_down = lm->keys_down;
251 	int ret;
252 	int i = 0;
253 
254 	/*
255 	 * Read all key events from the FIFO at once. Next READ_FIFO clears the
256 	 * FIFO even if we didn't read all events previously.
257 	 */
258 	ret = lm8323_read(lm, LM8323_CMD_READ_FIFO, key_fifo, LM8323_FIFO_LEN);
259 
260 	if (ret < 0) {
261 		dev_err(&lm->client->dev, "Failed reading fifo \n");
262 		return;
263 	}
264 	key_fifo[ret] = 0;
265 
266 	while ((event = key_fifo[i++])) {
267 		u8 key = lm8323_whichkey(event);
268 		int isdown = lm8323_ispress(event);
269 		unsigned short keycode = lm->keymap[key];
270 
271 		dev_vdbg(&lm->client->dev, "key 0x%02x %s\n",
272 			 key, isdown ? "down" : "up");
273 
274 		if (lm->kp_enabled) {
275 			input_event(lm->idev, EV_MSC, MSC_SCAN, key);
276 			input_report_key(lm->idev, keycode, isdown);
277 			input_sync(lm->idev);
278 		}
279 
280 		if (isdown)
281 			lm->keys_down++;
282 		else
283 			lm->keys_down--;
284 	}
285 
286 	/*
287 	 * Errata: We need to ensure that the chip never enters halt mode
288 	 * during a keypress, so set active time to 0.  When it's released,
289 	 * we can enter halt again, so set the active time back to normal.
290 	 */
291 	if (!old_keys_down && lm->keys_down)
292 		lm8323_set_active_time(lm, 0);
293 	if (old_keys_down && !lm->keys_down)
294 		lm8323_set_active_time(lm, lm->active_time);
295 }
296 
297 static void lm8323_process_error(struct lm8323_chip *lm)
298 {
299 	u8 error;
300 
301 	if (lm8323_read(lm, LM8323_CMD_READ_ERR, &error, 1) == 1) {
302 		if (error & ERR_FIFOOVER)
303 			dev_vdbg(&lm->client->dev, "fifo overflow!\n");
304 		if (error & ERR_KEYOVR)
305 			dev_vdbg(&lm->client->dev,
306 					"more than two keys pressed\n");
307 		if (error & ERR_CMDUNK)
308 			dev_vdbg(&lm->client->dev,
309 					"unknown command submitted\n");
310 		if (error & ERR_BADPAR)
311 			dev_vdbg(&lm->client->dev, "bad command parameter\n");
312 	}
313 }
314 
315 static void lm8323_reset(struct lm8323_chip *lm)
316 {
317 	/* The docs say we must pass 0xAA as the data byte. */
318 	lm8323_write(lm, 2, LM8323_CMD_RESET, 0xAA);
319 }
320 
321 static int lm8323_configure(struct lm8323_chip *lm)
322 {
323 	int keysize = (lm->size_x << 4) | lm->size_y;
324 	int clock = (CLK_SLOWCLKEN | CLK_RCPWM_EXTERNAL);
325 	int debounce = lm->debounce_time >> 2;
326 	int active = lm->active_time >> 2;
327 
328 	/*
329 	 * Active time must be greater than the debounce time: if it's
330 	 * a close-run thing, give ourselves a 12ms buffer.
331 	 */
332 	if (debounce >= active)
333 		active = debounce + 3;
334 
335 	lm8323_write(lm, 2, LM8323_CMD_WRITE_CFG, 0);
336 	lm8323_write(lm, 2, LM8323_CMD_WRITE_CLOCK, clock);
337 	lm8323_write(lm, 2, LM8323_CMD_SET_KEY_SIZE, keysize);
338 	lm8323_set_active_time(lm, lm->active_time);
339 	lm8323_write(lm, 2, LM8323_CMD_SET_DEBOUNCE, debounce);
340 	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_STATE, 0xff, 0xff);
341 	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_SEL, 0, 0);
342 
343 	/*
344 	 * Not much we can do about errors at this point, so just hope
345 	 * for the best.
346 	 */
347 
348 	return 0;
349 }
350 
351 static void pwm_done(struct lm8323_pwm *pwm)
352 {
353 	mutex_lock(&pwm->lock);
354 	pwm->running = false;
355 	if (pwm->desired_brightness != pwm->brightness)
356 		schedule_work(&pwm->work);
357 	mutex_unlock(&pwm->lock);
358 }
359 
360 /*
361  * Bottom half: handle the interrupt by posting key events, or dealing with
362  * errors appropriately.
363  */
364 static irqreturn_t lm8323_irq(int irq, void *_lm)
365 {
366 	struct lm8323_chip *lm = _lm;
367 	u8 ints;
368 	int i;
369 
370 	mutex_lock(&lm->lock);
371 
372 	while ((lm8323_read(lm, LM8323_CMD_READ_INT, &ints, 1) == 1) && ints) {
373 		if (likely(ints & INT_KEYPAD))
374 			process_keys(lm);
375 		if (ints & INT_ROTATOR) {
376 			/* We don't currently support the rotator. */
377 			dev_vdbg(&lm->client->dev, "rotator fired\n");
378 		}
379 		if (ints & INT_ERROR) {
380 			dev_vdbg(&lm->client->dev, "error!\n");
381 			lm8323_process_error(lm);
382 		}
383 		if (ints & INT_NOINIT) {
384 			dev_err(&lm->client->dev, "chip lost config; "
385 						  "reinitialising\n");
386 			lm8323_configure(lm);
387 		}
388 		for (i = 0; i < LM8323_NUM_PWMS; i++) {
389 			if (ints & (INT_PWM1 << i)) {
390 				dev_vdbg(&lm->client->dev,
391 					 "pwm%d engine completed\n", i);
392 				pwm_done(&lm->pwm[i]);
393 			}
394 		}
395 	}
396 
397 	mutex_unlock(&lm->lock);
398 
399 	return IRQ_HANDLED;
400 }
401 
402 /*
403  * Read the chip ID.
404  */
405 static int lm8323_read_id(struct lm8323_chip *lm, u8 *buf)
406 {
407 	int bytes;
408 
409 	bytes = lm8323_read(lm, LM8323_CMD_READ_ID, buf, 2);
410 	if (unlikely(bytes != 2))
411 		return -EIO;
412 
413 	return 0;
414 }
415 
416 static void lm8323_write_pwm_one(struct lm8323_pwm *pwm, int pos, u16 cmd)
417 {
418 	lm8323_write(pwm->chip, 4, LM8323_CMD_PWM_WRITE, (pos << 2) | pwm->id,
419 		     (cmd & 0xff00) >> 8, cmd & 0x00ff);
420 }
421 
422 /*
423  * Write a script into a given PWM engine, concluding with PWM_END.
424  * If 'kill' is nonzero, the engine will be shut down at the end
425  * of the script, producing a zero output. Otherwise the engine
426  * will be kept running at the final PWM level indefinitely.
427  */
428 static void lm8323_write_pwm(struct lm8323_pwm *pwm, int kill,
429 			     int len, const u16 *cmds)
430 {
431 	int i;
432 
433 	for (i = 0; i < len; i++)
434 		lm8323_write_pwm_one(pwm, i, cmds[i]);
435 
436 	lm8323_write_pwm_one(pwm, i++, PWM_END(kill));
437 	lm8323_write(pwm->chip, 2, LM8323_CMD_START_PWM, pwm->id);
438 	pwm->running = true;
439 }
440 
441 static void lm8323_pwm_work(struct work_struct *work)
442 {
443 	struct lm8323_pwm *pwm = work_to_pwm(work);
444 	int div512, perstep, steps, hz, up, kill;
445 	u16 pwm_cmds[3];
446 	int num_cmds = 0;
447 
448 	mutex_lock(&pwm->lock);
449 
450 	/*
451 	 * Do nothing if we're already at the requested level,
452 	 * or previous setting is not yet complete. In the latter
453 	 * case we will be called again when the previous PWM script
454 	 * finishes.
455 	 */
456 	if (pwm->running || pwm->desired_brightness == pwm->brightness)
457 		goto out;
458 
459 	kill = (pwm->desired_brightness == 0);
460 	up = (pwm->desired_brightness > pwm->brightness);
461 	steps = abs(pwm->desired_brightness - pwm->brightness);
462 
463 	/*
464 	 * Convert time (in ms) into a divisor (512 or 16 on a refclk of
465 	 * 32768Hz), and number of ticks per step.
466 	 */
467 	if ((pwm->fade_time / steps) > (32768 / 512)) {
468 		div512 = 1;
469 		hz = 32768 / 512;
470 	} else {
471 		div512 = 0;
472 		hz = 32768 / 16;
473 	}
474 
475 	perstep = (hz * pwm->fade_time) / (steps * 1000);
476 
477 	if (perstep == 0)
478 		perstep = 1;
479 	else if (perstep > 63)
480 		perstep = 63;
481 
482 	while (steps) {
483 		int s;
484 
485 		s = min(126, steps);
486 		pwm_cmds[num_cmds++] = PWM_RAMP(div512, perstep, s, up);
487 		steps -= s;
488 	}
489 
490 	lm8323_write_pwm(pwm, kill, num_cmds, pwm_cmds);
491 	pwm->brightness = pwm->desired_brightness;
492 
493  out:
494 	mutex_unlock(&pwm->lock);
495 }
496 
497 static void lm8323_pwm_set_brightness(struct led_classdev *led_cdev,
498 				      enum led_brightness brightness)
499 {
500 	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
501 	struct lm8323_chip *lm = pwm->chip;
502 
503 	mutex_lock(&pwm->lock);
504 	pwm->desired_brightness = brightness;
505 	mutex_unlock(&pwm->lock);
506 
507 	if (in_interrupt()) {
508 		schedule_work(&pwm->work);
509 	} else {
510 		/*
511 		 * Schedule PWM work as usual unless we are going into suspend
512 		 */
513 		mutex_lock(&lm->lock);
514 		if (likely(!lm->pm_suspend))
515 			schedule_work(&pwm->work);
516 		else
517 			lm8323_pwm_work(&pwm->work);
518 		mutex_unlock(&lm->lock);
519 	}
520 }
521 
522 static ssize_t lm8323_pwm_show_time(struct device *dev,
523 		struct device_attribute *attr, char *buf)
524 {
525 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
526 	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
527 
528 	return sprintf(buf, "%d\n", pwm->fade_time);
529 }
530 
531 static ssize_t lm8323_pwm_store_time(struct device *dev,
532 		struct device_attribute *attr, const char *buf, size_t len)
533 {
534 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
535 	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
536 	int ret, time;
537 
538 	ret = kstrtoint(buf, 10, &time);
539 	/* Numbers only, please. */
540 	if (ret)
541 		return ret;
542 
543 	pwm->fade_time = time;
544 
545 	return strlen(buf);
546 }
547 static DEVICE_ATTR(time, 0644, lm8323_pwm_show_time, lm8323_pwm_store_time);
548 
549 static struct attribute *lm8323_pwm_attrs[] = {
550 	&dev_attr_time.attr,
551 	NULL
552 };
553 ATTRIBUTE_GROUPS(lm8323_pwm);
554 
555 static int init_pwm(struct lm8323_chip *lm, int id, struct device *dev,
556 		    const char *name)
557 {
558 	struct lm8323_pwm *pwm;
559 	int err;
560 
561 	BUG_ON(id > 3);
562 
563 	pwm = &lm->pwm[id - 1];
564 
565 	pwm->id = id;
566 	pwm->fade_time = 0;
567 	pwm->brightness = 0;
568 	pwm->desired_brightness = 0;
569 	pwm->running = false;
570 	pwm->enabled = false;
571 	INIT_WORK(&pwm->work, lm8323_pwm_work);
572 	mutex_init(&pwm->lock);
573 	pwm->chip = lm;
574 
575 	if (name) {
576 		pwm->cdev.name = name;
577 		pwm->cdev.brightness_set = lm8323_pwm_set_brightness;
578 		pwm->cdev.groups = lm8323_pwm_groups;
579 
580 		err = devm_led_classdev_register(dev, &pwm->cdev);
581 		if (err) {
582 			dev_err(dev, "couldn't register PWM %d: %d\n", id, err);
583 			return err;
584 		}
585 		pwm->enabled = true;
586 	}
587 
588 	return 0;
589 }
590 
591 static ssize_t lm8323_show_disable(struct device *dev,
592 				   struct device_attribute *attr, char *buf)
593 {
594 	struct lm8323_chip *lm = dev_get_drvdata(dev);
595 
596 	return sprintf(buf, "%u\n", !lm->kp_enabled);
597 }
598 
599 static ssize_t lm8323_set_disable(struct device *dev,
600 				  struct device_attribute *attr,
601 				  const char *buf, size_t count)
602 {
603 	struct lm8323_chip *lm = dev_get_drvdata(dev);
604 	int ret;
605 	unsigned int i;
606 
607 	ret = kstrtouint(buf, 10, &i);
608 	if (ret)
609 		return ret;
610 
611 	mutex_lock(&lm->lock);
612 	lm->kp_enabled = !i;
613 	mutex_unlock(&lm->lock);
614 
615 	return count;
616 }
617 static DEVICE_ATTR(disable_kp, 0644, lm8323_show_disable, lm8323_set_disable);
618 
619 static struct attribute *lm8323_attrs[] = {
620 	&dev_attr_disable_kp.attr,
621 	NULL,
622 };
623 ATTRIBUTE_GROUPS(lm8323);
624 
625 static int lm8323_probe(struct i2c_client *client)
626 {
627 	struct lm8323_platform_data *pdata = dev_get_platdata(&client->dev);
628 	struct input_dev *idev;
629 	struct lm8323_chip *lm;
630 	int pwm;
631 	int i, err;
632 	unsigned long tmo;
633 	u8 data[2];
634 
635 	if (!pdata || !pdata->size_x || !pdata->size_y) {
636 		dev_err(&client->dev, "missing platform_data\n");
637 		return -EINVAL;
638 	}
639 
640 	if (pdata->size_x > 8) {
641 		dev_err(&client->dev, "invalid x size %d specified\n",
642 			pdata->size_x);
643 		return -EINVAL;
644 	}
645 
646 	if (pdata->size_y > 12) {
647 		dev_err(&client->dev, "invalid y size %d specified\n",
648 			pdata->size_y);
649 		return -EINVAL;
650 	}
651 
652 	lm = devm_kzalloc(&client->dev, sizeof(*lm), GFP_KERNEL);
653 	if (!lm)
654 		return -ENOMEM;
655 
656 	idev = devm_input_allocate_device(&client->dev);
657 	if (!idev)
658 		return -ENOMEM;
659 
660 	lm->client = client;
661 	lm->idev = idev;
662 	mutex_init(&lm->lock);
663 
664 	lm->size_x = pdata->size_x;
665 	lm->size_y = pdata->size_y;
666 	dev_vdbg(&client->dev, "Keypad size: %d x %d\n",
667 		 lm->size_x, lm->size_y);
668 
669 	lm->debounce_time = pdata->debounce_time;
670 	lm->active_time = pdata->active_time;
671 
672 	lm8323_reset(lm);
673 
674 	/*
675 	 * Nothing's set up to service the IRQ yet, so just spin for max.
676 	 * 100ms until we can configure.
677 	 */
678 	tmo = jiffies + msecs_to_jiffies(100);
679 	while (lm8323_read(lm, LM8323_CMD_READ_INT, data, 1) == 1) {
680 		if (data[0] & INT_NOINIT)
681 			break;
682 
683 		if (time_after(jiffies, tmo)) {
684 			dev_err(&client->dev,
685 				"timeout waiting for initialisation\n");
686 			break;
687 		}
688 
689 		msleep(1);
690 	}
691 
692 	lm8323_configure(lm);
693 
694 	/* If a true probe check the device */
695 	if (lm8323_read_id(lm, data) != 0) {
696 		dev_err(&client->dev, "device not found\n");
697 		return -ENODEV;
698 	}
699 
700 	for (pwm = 0; pwm < LM8323_NUM_PWMS; pwm++) {
701 		err = init_pwm(lm, pwm + 1, &client->dev,
702 			       pdata->pwm_names[pwm]);
703 		if (err)
704 			return err;
705 	}
706 
707 	lm->kp_enabled = true;
708 
709 	idev->name = pdata->name ? : "LM8323 keypad";
710 	snprintf(lm->phys, sizeof(lm->phys),
711 		 "%s/input-kp", dev_name(&client->dev));
712 	idev->phys = lm->phys;
713 
714 	idev->evbit[0] = BIT(EV_KEY) | BIT(EV_MSC);
715 	__set_bit(MSC_SCAN, idev->mscbit);
716 	for (i = 0; i < LM8323_KEYMAP_SIZE; i++) {
717 		__set_bit(pdata->keymap[i], idev->keybit);
718 		lm->keymap[i] = pdata->keymap[i];
719 	}
720 	__clear_bit(KEY_RESERVED, idev->keybit);
721 
722 	if (pdata->repeat)
723 		__set_bit(EV_REP, idev->evbit);
724 
725 	err = input_register_device(idev);
726 	if (err) {
727 		dev_dbg(&client->dev, "error registering input device\n");
728 		return err;
729 	}
730 
731 	err = devm_request_threaded_irq(&client->dev, client->irq,
732 					NULL, lm8323_irq,
733 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
734 					"lm8323", lm);
735 	if (err) {
736 		dev_err(&client->dev, "could not get IRQ %d\n", client->irq);
737 		return err;
738 	}
739 
740 	i2c_set_clientdata(client, lm);
741 
742 	device_init_wakeup(&client->dev, 1);
743 	enable_irq_wake(client->irq);
744 
745 	return 0;
746 }
747 
748 /*
749  * We don't need to explicitly suspend the chip, as it already switches off
750  * when there's no activity.
751  */
752 static int lm8323_suspend(struct device *dev)
753 {
754 	struct i2c_client *client = to_i2c_client(dev);
755 	struct lm8323_chip *lm = i2c_get_clientdata(client);
756 	int i;
757 
758 	irq_set_irq_wake(client->irq, 0);
759 	disable_irq(client->irq);
760 
761 	mutex_lock(&lm->lock);
762 	lm->pm_suspend = true;
763 	mutex_unlock(&lm->lock);
764 
765 	for (i = 0; i < 3; i++)
766 		if (lm->pwm[i].enabled)
767 			led_classdev_suspend(&lm->pwm[i].cdev);
768 
769 	return 0;
770 }
771 
772 static int lm8323_resume(struct device *dev)
773 {
774 	struct i2c_client *client = to_i2c_client(dev);
775 	struct lm8323_chip *lm = i2c_get_clientdata(client);
776 	int i;
777 
778 	mutex_lock(&lm->lock);
779 	lm->pm_suspend = false;
780 	mutex_unlock(&lm->lock);
781 
782 	for (i = 0; i < 3; i++)
783 		if (lm->pwm[i].enabled)
784 			led_classdev_resume(&lm->pwm[i].cdev);
785 
786 	enable_irq(client->irq);
787 	irq_set_irq_wake(client->irq, 1);
788 
789 	return 0;
790 }
791 
792 static DEFINE_SIMPLE_DEV_PM_OPS(lm8323_pm_ops, lm8323_suspend, lm8323_resume);
793 
794 static const struct i2c_device_id lm8323_id[] = {
795 	{ "lm8323" },
796 	{ }
797 };
798 
799 static struct i2c_driver lm8323_i2c_driver = {
800 	.driver = {
801 		.name		= "lm8323",
802 		.pm		= pm_sleep_ptr(&lm8323_pm_ops),
803 		.dev_groups	= lm8323_groups,
804 	},
805 	.probe		= lm8323_probe,
806 	.id_table	= lm8323_id,
807 };
808 MODULE_DEVICE_TABLE(i2c, lm8323_id);
809 
810 module_i2c_driver(lm8323_i2c_driver);
811 
812 MODULE_AUTHOR("Timo O. Karjalainen <timo.o.karjalainen@nokia.com>");
813 MODULE_AUTHOR("Daniel Stone");
814 MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
815 MODULE_DESCRIPTION("LM8323 keypad driver");
816 MODULE_LICENSE("GPL");
817 
818