cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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lm8323.c (22046B)


      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
    119struct 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
    133struct 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 */
    162static 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 */
    199static 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 */
    227static 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 */
    236static inline u8 lm8323_whichkey(u8 event)
    237{
    238	return event & 0x7f;
    239}
    240
    241static inline int lm8323_ispress(u8 event)
    242{
    243	return (event & 0x80) ? 1 : 0;
    244}
    245
    246static 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
    297static 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
    315static 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
    321static 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
    351static 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 */
    364static 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 */
    405static 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
    416static 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 */
    428static 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
    441static 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
    497static 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
    522static 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
    531static 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}
    547static DEVICE_ATTR(time, 0644, lm8323_pwm_show_time, lm8323_pwm_store_time);
    548
    549static struct attribute *lm8323_pwm_attrs[] = {
    550	&dev_attr_time.attr,
    551	NULL
    552};
    553ATTRIBUTE_GROUPS(lm8323_pwm);
    554
    555static int init_pwm(struct lm8323_chip *lm, int id, struct device *dev,
    556		    const char *name)
    557{
    558	struct lm8323_pwm *pwm;
    559
    560	BUG_ON(id > 3);
    561
    562	pwm = &lm->pwm[id - 1];
    563
    564	pwm->id = id;
    565	pwm->fade_time = 0;
    566	pwm->brightness = 0;
    567	pwm->desired_brightness = 0;
    568	pwm->running = false;
    569	pwm->enabled = false;
    570	INIT_WORK(&pwm->work, lm8323_pwm_work);
    571	mutex_init(&pwm->lock);
    572	pwm->chip = lm;
    573
    574	if (name) {
    575		pwm->cdev.name = name;
    576		pwm->cdev.brightness_set = lm8323_pwm_set_brightness;
    577		pwm->cdev.groups = lm8323_pwm_groups;
    578		if (led_classdev_register(dev, &pwm->cdev) < 0) {
    579			dev_err(dev, "couldn't register PWM %d\n", id);
    580			return -1;
    581		}
    582		pwm->enabled = true;
    583	}
    584
    585	return 0;
    586}
    587
    588static struct i2c_driver lm8323_i2c_driver;
    589
    590static ssize_t lm8323_show_disable(struct device *dev,
    591				   struct device_attribute *attr, char *buf)
    592{
    593	struct lm8323_chip *lm = dev_get_drvdata(dev);
    594
    595	return sprintf(buf, "%u\n", !lm->kp_enabled);
    596}
    597
    598static ssize_t lm8323_set_disable(struct device *dev,
    599				  struct device_attribute *attr,
    600				  const char *buf, size_t count)
    601{
    602	struct lm8323_chip *lm = dev_get_drvdata(dev);
    603	int ret;
    604	unsigned int i;
    605
    606	ret = kstrtouint(buf, 10, &i);
    607	if (ret)
    608		return ret;
    609
    610	mutex_lock(&lm->lock);
    611	lm->kp_enabled = !i;
    612	mutex_unlock(&lm->lock);
    613
    614	return count;
    615}
    616static DEVICE_ATTR(disable_kp, 0644, lm8323_show_disable, lm8323_set_disable);
    617
    618static int lm8323_probe(struct i2c_client *client,
    619				  const struct i2c_device_id *id)
    620{
    621	struct lm8323_platform_data *pdata = dev_get_platdata(&client->dev);
    622	struct input_dev *idev;
    623	struct lm8323_chip *lm;
    624	int pwm;
    625	int i, err;
    626	unsigned long tmo;
    627	u8 data[2];
    628
    629	if (!pdata || !pdata->size_x || !pdata->size_y) {
    630		dev_err(&client->dev, "missing platform_data\n");
    631		return -EINVAL;
    632	}
    633
    634	if (pdata->size_x > 8) {
    635		dev_err(&client->dev, "invalid x size %d specified\n",
    636			pdata->size_x);
    637		return -EINVAL;
    638	}
    639
    640	if (pdata->size_y > 12) {
    641		dev_err(&client->dev, "invalid y size %d specified\n",
    642			pdata->size_y);
    643		return -EINVAL;
    644	}
    645
    646	lm = kzalloc(sizeof *lm, GFP_KERNEL);
    647	idev = input_allocate_device();
    648	if (!lm || !idev) {
    649		err = -ENOMEM;
    650		goto fail1;
    651	}
    652
    653	lm->client = client;
    654	lm->idev = idev;
    655	mutex_init(&lm->lock);
    656
    657	lm->size_x = pdata->size_x;
    658	lm->size_y = pdata->size_y;
    659	dev_vdbg(&client->dev, "Keypad size: %d x %d\n",
    660		 lm->size_x, lm->size_y);
    661
    662	lm->debounce_time = pdata->debounce_time;
    663	lm->active_time = pdata->active_time;
    664
    665	lm8323_reset(lm);
    666
    667	/* Nothing's set up to service the IRQ yet, so just spin for max.
    668	 * 100ms until we can configure. */
    669	tmo = jiffies + msecs_to_jiffies(100);
    670	while (lm8323_read(lm, LM8323_CMD_READ_INT, data, 1) == 1) {
    671		if (data[0] & INT_NOINIT)
    672			break;
    673
    674		if (time_after(jiffies, tmo)) {
    675			dev_err(&client->dev,
    676				"timeout waiting for initialisation\n");
    677			break;
    678		}
    679
    680		msleep(1);
    681	}
    682
    683	lm8323_configure(lm);
    684
    685	/* If a true probe check the device */
    686	if (lm8323_read_id(lm, data) != 0) {
    687		dev_err(&client->dev, "device not found\n");
    688		err = -ENODEV;
    689		goto fail1;
    690	}
    691
    692	for (pwm = 0; pwm < LM8323_NUM_PWMS; pwm++) {
    693		err = init_pwm(lm, pwm + 1, &client->dev,
    694			       pdata->pwm_names[pwm]);
    695		if (err < 0)
    696			goto fail2;
    697	}
    698
    699	lm->kp_enabled = true;
    700	err = device_create_file(&client->dev, &dev_attr_disable_kp);
    701	if (err < 0)
    702		goto fail2;
    703
    704	idev->name = pdata->name ? : "LM8323 keypad";
    705	snprintf(lm->phys, sizeof(lm->phys),
    706		 "%s/input-kp", dev_name(&client->dev));
    707	idev->phys = lm->phys;
    708
    709	idev->evbit[0] = BIT(EV_KEY) | BIT(EV_MSC);
    710	__set_bit(MSC_SCAN, idev->mscbit);
    711	for (i = 0; i < LM8323_KEYMAP_SIZE; i++) {
    712		__set_bit(pdata->keymap[i], idev->keybit);
    713		lm->keymap[i] = pdata->keymap[i];
    714	}
    715	__clear_bit(KEY_RESERVED, idev->keybit);
    716
    717	if (pdata->repeat)
    718		__set_bit(EV_REP, idev->evbit);
    719
    720	err = input_register_device(idev);
    721	if (err) {
    722		dev_dbg(&client->dev, "error registering input device\n");
    723		goto fail3;
    724	}
    725
    726	err = request_threaded_irq(client->irq, NULL, lm8323_irq,
    727			  IRQF_TRIGGER_LOW|IRQF_ONESHOT, "lm8323", lm);
    728	if (err) {
    729		dev_err(&client->dev, "could not get IRQ %d\n", client->irq);
    730		goto fail4;
    731	}
    732
    733	i2c_set_clientdata(client, lm);
    734
    735	device_init_wakeup(&client->dev, 1);
    736	enable_irq_wake(client->irq);
    737
    738	return 0;
    739
    740fail4:
    741	input_unregister_device(idev);
    742	idev = NULL;
    743fail3:
    744	device_remove_file(&client->dev, &dev_attr_disable_kp);
    745fail2:
    746	while (--pwm >= 0)
    747		if (lm->pwm[pwm].enabled)
    748			led_classdev_unregister(&lm->pwm[pwm].cdev);
    749fail1:
    750	input_free_device(idev);
    751	kfree(lm);
    752	return err;
    753}
    754
    755static int lm8323_remove(struct i2c_client *client)
    756{
    757	struct lm8323_chip *lm = i2c_get_clientdata(client);
    758	int i;
    759
    760	disable_irq_wake(client->irq);
    761	free_irq(client->irq, lm);
    762
    763	input_unregister_device(lm->idev);
    764
    765	device_remove_file(&lm->client->dev, &dev_attr_disable_kp);
    766
    767	for (i = 0; i < 3; i++)
    768		if (lm->pwm[i].enabled)
    769			led_classdev_unregister(&lm->pwm[i].cdev);
    770
    771	kfree(lm);
    772
    773	return 0;
    774}
    775
    776#ifdef CONFIG_PM_SLEEP
    777/*
    778 * We don't need to explicitly suspend the chip, as it already switches off
    779 * when there's no activity.
    780 */
    781static int lm8323_suspend(struct device *dev)
    782{
    783	struct i2c_client *client = to_i2c_client(dev);
    784	struct lm8323_chip *lm = i2c_get_clientdata(client);
    785	int i;
    786
    787	irq_set_irq_wake(client->irq, 0);
    788	disable_irq(client->irq);
    789
    790	mutex_lock(&lm->lock);
    791	lm->pm_suspend = true;
    792	mutex_unlock(&lm->lock);
    793
    794	for (i = 0; i < 3; i++)
    795		if (lm->pwm[i].enabled)
    796			led_classdev_suspend(&lm->pwm[i].cdev);
    797
    798	return 0;
    799}
    800
    801static int lm8323_resume(struct device *dev)
    802{
    803	struct i2c_client *client = to_i2c_client(dev);
    804	struct lm8323_chip *lm = i2c_get_clientdata(client);
    805	int i;
    806
    807	mutex_lock(&lm->lock);
    808	lm->pm_suspend = false;
    809	mutex_unlock(&lm->lock);
    810
    811	for (i = 0; i < 3; i++)
    812		if (lm->pwm[i].enabled)
    813			led_classdev_resume(&lm->pwm[i].cdev);
    814
    815	enable_irq(client->irq);
    816	irq_set_irq_wake(client->irq, 1);
    817
    818	return 0;
    819}
    820#endif
    821
    822static SIMPLE_DEV_PM_OPS(lm8323_pm_ops, lm8323_suspend, lm8323_resume);
    823
    824static const struct i2c_device_id lm8323_id[] = {
    825	{ "lm8323", 0 },
    826	{ }
    827};
    828
    829static struct i2c_driver lm8323_i2c_driver = {
    830	.driver = {
    831		.name	= "lm8323",
    832		.pm	= &lm8323_pm_ops,
    833	},
    834	.probe		= lm8323_probe,
    835	.remove		= lm8323_remove,
    836	.id_table	= lm8323_id,
    837};
    838MODULE_DEVICE_TABLE(i2c, lm8323_id);
    839
    840module_i2c_driver(lm8323_i2c_driver);
    841
    842MODULE_AUTHOR("Timo O. Karjalainen <timo.o.karjalainen@nokia.com>");
    843MODULE_AUTHOR("Daniel Stone");
    844MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
    845MODULE_DESCRIPTION("LM8323 keypad driver");
    846MODULE_LICENSE("GPL");
    847