OMAP3: PM: Prevented DVFS state switches when enabling off-mode

[linux-ginger.git] / drivers / input / keyboard / lm8323.c

/*
 * drivers/i2c/chips/lm8323.c
 *
 * Copyright (C) 2007-2009 Nokia Corporation
 *
 * Written by Daniel Stone <daniel.stone@nokia.com>
 *            Timo O. Karjalainen <timo.o.karjalainen@nokia.com>
 *
 * Updated by Felipe Balbi <felipe.balbi@nokia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation (version 2 of the License only).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/leds.h>
#include <linux/i2c/lm8323.h>

/* Commands to send to the chip. */
#define LM8323_CMD_READ_ID              0x80 /* Read chip ID. */
#define LM8323_CMD_WRITE_CFG            0x81 /* Set configuration item. */
#define LM8323_CMD_READ_INT             0x82 /* Get interrupt status. */
#define LM8323_CMD_RESET                0x83 /* Reset, same as external one */
#define LM8323_CMD_WRITE_PORT_SEL       0x85 /* Set GPIO in/out. */
#define LM8323_CMD_WRITE_PORT_STATE     0x86 /* Set GPIO pullup. */
#define LM8323_CMD_READ_PORT_SEL        0x87 /* Get GPIO in/out. */
#define LM8323_CMD_READ_PORT_STATE      0x88 /* Get GPIO pullup. */
#define LM8323_CMD_READ_FIFO            0x89 /* Read byte from FIFO. */
#define LM8323_CMD_RPT_READ_FIFO        0x8a /* Read FIFO (no increment). */
#define LM8323_CMD_SET_ACTIVE           0x8b /* Set active time. */
#define LM8323_CMD_READ_ERR             0x8c /* Get error status. */
#define LM8323_CMD_READ_ROTATOR         0x8e /* Read rotator status. */
#define LM8323_CMD_SET_DEBOUNCE         0x8f /* Set debouncing time. */
#define LM8323_CMD_SET_KEY_SIZE         0x90 /* Set keypad size. */
#define LM8323_CMD_READ_KEY_SIZE        0x91 /* Get keypad size. */
#define LM8323_CMD_READ_CFG             0x92 /* Get configuration item. */
#define LM8323_CMD_WRITE_CLOCK          0x93 /* Set clock config. */
#define LM8323_CMD_READ_CLOCK           0x94 /* Get clock config. */
#define LM8323_CMD_PWM_WRITE            0x95 /* Write PWM script. */
#define LM8323_CMD_START_PWM            0x96 /* Start PWM engine. */
#define LM8323_CMD_STOP_PWM             0x97 /* Stop PWM engine. */

/* Interrupt status. */
#define INT_KEYPAD                      0x01 /* Key event. */
#define INT_ROTATOR                     0x02 /* Rotator event. */
#define INT_ERROR                       0x08 /* Error: use CMD_READ_ERR. */
#define INT_NOINIT                      0x10 /* Lost configuration. */
#define INT_PWM1                        0x20 /* PWM1 stopped. */
#define INT_PWM2                        0x40 /* PWM2 stopped. */
#define INT_PWM3                        0x80 /* PWM3 stopped. */

/* Errors (signalled by INT_ERROR, read with CMD_READ_ERR). */
#define ERR_BADPAR                      0x01 /* Bad parameter. */
#define ERR_CMDUNK                      0x02 /* Unknown command. */
#define ERR_KEYOVR                      0x04 /* Too many keys pressed. */
#define ERR_FIFOOVER                    0x40 /* FIFO overflow. */

/* Configuration keys (CMD_{WRITE,READ}_CFG). */
#define CFG_MUX1SEL                     0x01 /* Select MUX1_OUT input. */
#define CFG_MUX1EN                      0x02 /* Enable MUX1_OUT. */
#define CFG_MUX2SEL                     0x04 /* Select MUX2_OUT input. */
#define CFG_MUX2EN                      0x08 /* Enable MUX2_OUT. */
#define CFG_PSIZE                       0x20 /* Package size (must be 0). */
#define CFG_ROTEN                       0x40 /* Enable rotator. */

/* Clock settings (CMD_{WRITE,READ}_CLOCK). */
#define CLK_RCPWM_INTERNAL              0x00
#define CLK_RCPWM_EXTERNAL              0x03
#define CLK_SLOWCLKEN                   0x08 /* Enable 32.768kHz clock. */
#define CLK_SLOWCLKOUT                  0x40 /* Enable slow pulse output. */

/* The possible addresses corresponding to CONFIG1 and CONFIG2 pin wirings. */
#define LM8323_I2C_ADDR00               (0x84 >> 1)     /* 1000 010x */
#define LM8323_I2C_ADDR01               (0x86 >> 1)     /* 1000 011x */
#define LM8323_I2C_ADDR10               (0x88 >> 1)     /* 1000 100x */
#define LM8323_I2C_ADDR11               (0x8A >> 1)     /* 1000 101x */

/* Key event fifo length */
#define LM8323_FIFO_LEN                 15

/* Commands for PWM engine; feed in with PWM_WRITE. */
/* Load ramp counter from duty cycle field (range 0 - 0xff). */
#define PWM_SET(v)                      (0x4000 | ((v) & 0xff))
/* Go to start of script. */
#define PWM_GOTOSTART                   0x0000
/*
 * Stop engine (generates interrupt).  If reset is 1, clear the program
 * counter, else leave it.
 */
#define PWM_END(reset)                  (0xc000 | (!!(reset) << 11))
/*
 * Ramp.  If s is 1, divide clock by 512, else divide clock by 16.
 * Take t clock scales (up to 63) per step, for n steps (up to 126).
 * If u is set, ramp up, else ramp down.
 */
#define PWM_RAMP(s, t, n, u)            ((!!(s) << 14) | ((t) & 0x3f) << 8 | \
                                         ((n) & 0x7f) | ((u) ? 0 : 0x80))
/*
 * Loop (i.e. jump back to pos) for a given number of iterations (up to 63).
 * If cnt is zero, execute until PWM_END is encountered.
 */
#define PWM_LOOP(cnt, pos)              (0xa000 | (((cnt) & 0x3f) << 7) | \
                                         ((pos) & 0x3f))
/*
 * Wait for trigger.  Argument is a mask of channels, shifted by the channel
 * number, e.g. 0xa for channels 3 and 1.  Note that channels are numbered
 * from 1, not 0.
 */
#define PWM_WAIT_TRIG(chans)            (0xe000 | (((chans) & 0x7) << 6))
/* Send trigger.  Argument is same as PWM_WAIT_TRIG. */
#define PWM_SEND_TRIG(chans)            (0xe000 | ((chans) & 0x7))

struct lm8323_pwm {
        int                     id;
        int                     fade_time;
        int                     brightness;
        int                     desired_brightness;
        bool                    enabled;
        bool                    running;
        /* pwm lock */
        struct mutex            lock;
        struct work_struct      work;
        struct led_classdev     cdev;
        struct lm8323_chip      *chip;
};

struct lm8323_chip {
        /* device lock */
        struct mutex            lock;
        struct i2c_client       *client;
        struct work_struct      work;
        struct input_dev        *idev;
        bool                    kp_enabled;
        bool                    pm_suspend;
        unsigned                keys_down;
        char                    phys[32];
        unsigned short          keymap[LM8323_KEYMAP_SIZE];
        int                     size_x;
        int                     size_y;
        int                     debounce_time;
        int                     active_time;
        struct lm8323_pwm       pwm[LM8323_NUM_PWMS];
};

#define client_to_lm8323(c)     container_of(c, struct lm8323_chip, client)
#define dev_to_lm8323(d)        container_of(d, struct lm8323_chip, client->dev)
#define work_to_lm8323(w)       container_of(w, struct lm8323_chip, work)
#define cdev_to_pwm(c)          container_of(c, struct lm8323_pwm, cdev)
#define work_to_pwm(w)          container_of(w, struct lm8323_pwm, work)

#define LM8323_MAX_DATA 8

/*
 * To write, we just access the chip's address in write mode, and dump the
 * command and data out on the bus.  The command byte and data are taken as
 * sequential u8s out of varargs, to a maximum of LM8323_MAX_DATA.
 */
static int lm8323_write(struct lm8323_chip *lm, int len, ...)
{
        int ret, i;
        va_list ap;
        u8 data[LM8323_MAX_DATA];

        va_start(ap, len);

        if (unlikely(len > LM8323_MAX_DATA)) {
                dev_err(&lm->client->dev, "tried to send %d bytes\n", len);
                va_end(ap);
                return 0;
        }

        for (i = 0; i < len; i++)
                data[i] = va_arg(ap, int);

        va_end(ap);

        /*
         * If the host is asleep while we send the data, we can get a NACK
         * back while it wakes up, so try again, once.
         */
        ret = i2c_master_send(lm->client, data, len);
        if (unlikely(ret == -EREMOTEIO))
                ret = i2c_master_send(lm->client, data, len);
        if (unlikely(ret != len))
                dev_err(&lm->client->dev, "sent %d bytes of %d total\n",
                        len, ret);

        return ret;
}

/*
 * To read, we first send the command byte to the chip and end the transaction,
 * then access the chip in read mode, at which point it will send the data.
 */
static int lm8323_read(struct lm8323_chip *lm, u8 cmd, u8 *buf, int len)
{
        int ret;

        /*
         * If the host is asleep while we send the byte, we can get a NACK
         * back while it wakes up, so try again, once.
         */
        ret = i2c_master_send(lm->client, &cmd, 1);
        if (unlikely(ret == -EREMOTEIO))
                ret = i2c_master_send(lm->client, &cmd, 1);
        if (unlikely(ret != 1)) {
                dev_err(&lm->client->dev, "sending read cmd 0x%02x failed\n",
                        cmd);
                return 0;
        }

        ret = i2c_master_recv(lm->client, buf, len);
        if (unlikely(ret != len))
                dev_err(&lm->client->dev, "wanted %d bytes, got %d\n",
                        len, ret);

        return ret;
}

/*
 * Set the chip active time (idle time before it enters halt).
 */
static void lm8323_set_active_time(struct lm8323_chip *lm, int time)
{
        lm8323_write(lm, 2, LM8323_CMD_SET_ACTIVE, time >> 2);
}

/*
 * The signals are AT-style: the low 7 bits are the keycode, and the top
 * bit indicates the state (1 for down, 0 for up).
 */
static inline u8 lm8323_whichkey(u8 event)
{
        return event & 0x7f;
}

static inline int lm8323_ispress(u8 event)
{
        return (event & 0x80) ? 1 : 0;
}

static void process_keys(struct lm8323_chip *lm)
{
        u8 event;
        u8 key_fifo[LM8323_FIFO_LEN + 1];
        int old_keys_down = lm->keys_down;
        int ret;
        int i = 0;

        /*
         * Read all key events from the FIFO at once. Next READ_FIFO clears the
         * FIFO even if we didn't read all events previously.
         */
        ret = lm8323_read(lm, LM8323_CMD_READ_FIFO, key_fifo, LM8323_FIFO_LEN);

        if (ret < 0) {
                dev_err(&lm->client->dev, "Failed reading fifo \n");
                return;
        }
        key_fifo[ret] = 0;

        while ((event = key_fifo[i++])) {
                u8 key = lm8323_whichkey(event);
                int isdown = lm8323_ispress(event);
                unsigned short keycode = lm->keymap[key];

                dev_vdbg(&lm->client->dev, "key 0x%02x %s\n",
                         key, isdown ? "down" : "up");

                if (lm->kp_enabled) {
                        input_event(lm->idev, EV_MSC, MSC_SCAN, key);
                        input_report_key(lm->idev, keycode, isdown);
                        input_sync(lm->idev);
                }

                if (isdown)
                        lm->keys_down++;
                else
                        lm->keys_down--;
        }

        /*
         * Errata: We need to ensure that the chip never enters halt mode
         * during a keypress, so set active time to 0.  When it's released,
         * we can enter halt again, so set the active time back to normal.
         */
        if (!old_keys_down && lm->keys_down)
                lm8323_set_active_time(lm, 0);
        if (old_keys_down && !lm->keys_down)
                lm8323_set_active_time(lm, lm->active_time);
}

static void lm8323_process_error(struct lm8323_chip *lm)
{
        u8 error;

        if (lm8323_read(lm, LM8323_CMD_READ_ERR, &error, 1) == 1) {
                if (error & ERR_FIFOOVER)
                        dev_vdbg(&lm->client->dev, "fifo overflow!\n");
                if (error & ERR_KEYOVR)
                        dev_vdbg(&lm->client->dev,
                                        "more than two keys pressed\n");
                if (error & ERR_CMDUNK)
                        dev_vdbg(&lm->client->dev,
                                        "unknown command submitted\n");
                if (error & ERR_BADPAR)
                        dev_vdbg(&lm->client->dev, "bad command parameter\n");
        }
}

static void lm8323_reset(struct lm8323_chip *lm)
{
        /* The docs say we must pass 0xAA as the data byte. */
        lm8323_write(lm, 2, LM8323_CMD_RESET, 0xAA);
}

static int lm8323_configure(struct lm8323_chip *lm)
{
        int keysize = (lm->size_x << 4) | lm->size_y;
        int clock = (CLK_SLOWCLKEN | CLK_RCPWM_EXTERNAL);
        int debounce = lm->debounce_time >> 2;
        int active = lm->active_time >> 2;

        /*
         * Active time must be greater than the debounce time: if it's
         * a close-run thing, give ourselves a 12ms buffer.
         */
        if (debounce >= active)
                active = debounce + 3;

        lm8323_write(lm, 2, LM8323_CMD_WRITE_CFG, 0);
        lm8323_write(lm, 2, LM8323_CMD_WRITE_CLOCK, clock);
        lm8323_write(lm, 2, LM8323_CMD_SET_KEY_SIZE, keysize);
        lm8323_set_active_time(lm, lm->active_time);
        lm8323_write(lm, 2, LM8323_CMD_SET_DEBOUNCE, debounce);
        lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_STATE, 0xff, 0xff);
        lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_SEL, 0, 0);

        /*
         * Not much we can do about errors at this point, so just hope
         * for the best.
         */

        return 0;
}

static void pwm_done(struct lm8323_pwm *pwm)
{
        mutex_lock(&pwm->lock);
        pwm->running = false;
        if (pwm->desired_brightness != pwm->brightness)
                schedule_work(&pwm->work);
        mutex_unlock(&pwm->lock);
}

/*
 * Bottom half: handle the interrupt by posting key events, or dealing with
 * errors appropriately.
 */
static void lm8323_work(struct work_struct *work)
{
        struct lm8323_chip *lm = work_to_lm8323(work);
        u8 ints;
        int i;

        mutex_lock(&lm->lock);

        while ((lm8323_read(lm, LM8323_CMD_READ_INT, &ints, 1) == 1) && ints) {
                if (likely(ints & INT_KEYPAD))
                        process_keys(lm);
                if (ints & INT_ROTATOR) {
                        /* We don't currently support the rotator. */
                        dev_vdbg(&lm->client->dev, "rotator fired\n");
                }
                if (ints & INT_ERROR) {
                        dev_vdbg(&lm->client->dev, "error!\n");
                        lm8323_process_error(lm);
                }
                if (ints & INT_NOINIT) {
                        dev_err(&lm->client->dev, "chip lost config; "
                                                  "reinitialising\n");
                        lm8323_configure(lm);
                }
                for (i = 0; i < LM8323_NUM_PWMS; i++) {
                        if (ints & (1 << (INT_PWM1 + i))) {
                                dev_vdbg(&lm->client->dev,
                                         "pwm%d engine completed\n", i);
                                pwm_done(&lm->pwm[i]);
                        }
                }
        }

        mutex_unlock(&lm->lock);
}

/*
 * We cannot use I2C in interrupt context, so we just schedule work.
 */
static irqreturn_t lm8323_irq(int irq, void *data)
{
        struct lm8323_chip *lm = data;

        schedule_work(&lm->work);

        return IRQ_HANDLED;
}

/*
 * Read the chip ID.
 */
static int lm8323_read_id(struct lm8323_chip *lm, u8 *buf)
{
        int bytes;

        bytes = lm8323_read(lm, LM8323_CMD_READ_ID, buf, 2);
        if (unlikely(bytes != 2))
                return -EIO;

        return 0;
}

static void lm8323_write_pwm_one(struct lm8323_pwm *pwm, int pos, u16 cmd)
{
        lm8323_write(pwm->chip, 4, LM8323_CMD_PWM_WRITE, (pos << 2) | pwm->id,
                     (cmd & 0xff00) >> 8, cmd & 0x00ff);
}

/*
 * Write a script into a given PWM engine, concluding with PWM_END.
 * If 'kill' is nonzero, the engine will be shut down at the end
 * of the script, producing a zero output. Otherwise the engine
 * will be kept running at the final PWM level indefinitely.
 */
static void lm8323_write_pwm(struct lm8323_pwm *pwm, int kill,
                             int len, const u16 *cmds)
{
        int i;

        for (i = 0; i < len; i++)
                lm8323_write_pwm_one(pwm, i, cmds[i]);

        lm8323_write_pwm_one(pwm, i++, PWM_END(kill));
        lm8323_write(pwm->chip, 2, LM8323_CMD_START_PWM, pwm->id);
        pwm->running = true;
}

static void lm8323_pwm_work(struct work_struct *work)
{
        struct lm8323_pwm *pwm = work_to_pwm(work);
        int div512, perstep, steps, hz, up, kill;
        u16 pwm_cmds[3];
        int num_cmds = 0;

        mutex_lock(&pwm->lock);

        /*
         * Do nothing if we're already at the requested level,
         * or previous setting is not yet complete. In the latter
         * case we will be called again when the previous PWM script
         * finishes.
         */
        if (pwm->running || pwm->desired_brightness == pwm->brightness)
                goto out;

        kill = (pwm->desired_brightness == 0);
        up = (pwm->desired_brightness > pwm->brightness);
        steps = abs(pwm->desired_brightness - pwm->brightness);

        /*
         * Convert time (in ms) into a divisor (512 or 16 on a refclk of
         * 32768Hz), and number of ticks per step.
         */
        if ((pwm->fade_time / steps) > (32768 / 512)) {
                div512 = 1;
                hz = 32768 / 512;
        } else {
                div512 = 0;
                hz = 32768 / 16;
        }

        perstep = (hz * pwm->fade_time) / (steps * 1000);

        if (perstep == 0)
                perstep = 1;
        else if (perstep > 63)
                perstep = 63;

        while (steps) {
                int s;

                s = min(126, steps);
                pwm_cmds[num_cmds++] = PWM_RAMP(div512, perstep, s, up);
                steps -= s;
        }

        lm8323_write_pwm(pwm, kill, num_cmds, pwm_cmds);
        pwm->brightness = pwm->desired_brightness;

 out:
        mutex_unlock(&pwm->lock);
}

static void lm8323_pwm_set_brightness(struct led_classdev *led_cdev,
                                      enum led_brightness brightness)
{
        struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
        struct lm8323_chip *lm = pwm->chip;

        mutex_lock(&pwm->lock);
        pwm->desired_brightness = brightness;
        mutex_unlock(&pwm->lock);

        if (in_interrupt()) {
                schedule_work(&pwm->work);
        } else {
                /*
                 * Schedule PWM work as usual unless we are going into suspend
                 */
                mutex_lock(&lm->lock);
                if (likely(!lm->pm_suspend))
                        schedule_work(&pwm->work);
                else
                        lm8323_pwm_work(&pwm->work);
                mutex_unlock(&lm->lock);
        }
}

static ssize_t lm8323_pwm_show_time(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);

        return sprintf(buf, "%d\n", pwm->fade_time);
}

static ssize_t lm8323_pwm_store_time(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t len)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
        int ret;
        unsigned long time;

        ret = strict_strtoul(buf, 10, &time);
        /* Numbers only, please. */
        if (ret)
                return -EINVAL;

        pwm->fade_time = time;

        return strlen(buf);
}
static DEVICE_ATTR(time, 0644, lm8323_pwm_show_time, lm8323_pwm_store_time);

static int init_pwm(struct lm8323_chip *lm, int id, struct device *dev,
                    const char *name)
{
        struct lm8323_pwm *pwm;

        BUG_ON(id > 3);

        pwm = &lm->pwm[id - 1];

        pwm->id = id;
        pwm->fade_time = 0;
        pwm->brightness = 0;
        pwm->desired_brightness = 0;
        pwm->running = false;
        pwm->enabled = false;
        INIT_WORK(&pwm->work, lm8323_pwm_work);
        mutex_init(&pwm->lock);
        pwm->chip = lm;

        if (name) {
                pwm->cdev.name = name;
                pwm->cdev.brightness_set = lm8323_pwm_set_brightness;
                if (led_classdev_register(dev, &pwm->cdev) < 0) {
                        dev_err(dev, "couldn't register PWM %d\n", id);
                        return -1;
                }
                if (device_create_file(pwm->cdev.dev,
                                        &dev_attr_time) < 0) {
                        dev_err(dev, "couldn't register time attribute\n");
                        led_classdev_unregister(&pwm->cdev);
                        return -1;
                }
                pwm->enabled = true;
        }

        return 0;
}

static struct i2c_driver lm8323_i2c_driver;

static ssize_t lm8323_show_disable(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct lm8323_chip *lm = dev_get_drvdata(dev);

        return sprintf(buf, "%u\n", !lm->kp_enabled);
}

static ssize_t lm8323_set_disable(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        struct lm8323_chip *lm = dev_get_drvdata(dev);
        int ret;
        unsigned long i;

        ret = strict_strtoul(buf, 10, &i);

        mutex_lock(&lm->lock);
        lm->kp_enabled = !i;
        mutex_unlock(&lm->lock);

        return count;
}
static DEVICE_ATTR(disable_kp, 0644, lm8323_show_disable, lm8323_set_disable);

static int __devinit lm8323_probe(struct i2c_client *client,
                                  const struct i2c_device_id *id)
{
        struct lm8323_platform_data *pdata = client->dev.platform_data;
        struct input_dev *idev;
        struct lm8323_chip *lm;
        int i, err;
        unsigned long tmo;
        u8 data[2];

        if (!pdata || !pdata->size_x || !pdata->size_y) {
                dev_err(&client->dev, "missing platform_data\n");
                return -EINVAL;
        }

        if (pdata->size_x > 8) {
                dev_err(&client->dev, "invalid x size %d specified\n",
                        pdata->size_x);
                return -EINVAL;
        }

        if (pdata->size_y > 12) {
                dev_err(&client->dev, "invalid y size %d specified\n",
                        pdata->size_y);
                return -EINVAL;
        }

        lm = kzalloc(sizeof *lm, GFP_KERNEL);
        idev = input_allocate_device();
        if (!lm || !idev) {
                err = -ENOMEM;
                goto fail1;
        }

        i2c_set_clientdata(client, lm);

        lm->client = client;
        lm->idev = idev;
        mutex_init(&lm->lock);
        INIT_WORK(&lm->work, lm8323_work);

        lm->size_x = pdata->size_x;
        lm->size_y = pdata->size_y;
        dev_vdbg(&client->dev, "Keypad size: %d x %d\n",
                 lm->size_x, lm->size_y);

        lm->debounce_time = pdata->debounce_time;
        lm->active_time = pdata->active_time;

        lm8323_reset(lm);

        /* Nothing's set up to service the IRQ yet, so just spin for max.
         * 100ms until we can configure. */
        tmo = jiffies + msecs_to_jiffies(100);
        while (lm8323_read(lm, LM8323_CMD_READ_INT, data, 1) == 1) {
                if (data[0] & INT_NOINIT)
                        break;

                if (time_after(jiffies, tmo)) {
                        dev_err(&client->dev,
                                "timeout waiting for initialisation\n");
                        break;
                }

                msleep(1);
        }

        lm8323_configure(lm);

        /* If a true probe check the device */
        if (lm8323_read_id(lm, data) != 0) {
                dev_err(&client->dev, "device not found\n");
                err = -ENODEV;
                goto fail1;
        }

        for (i = 0; i < LM8323_NUM_PWMS; i++) {
                err = init_pwm(lm, i + 1, &client->dev, pdata->pwm_names[i]);
                if (err < 0)
                        goto fail2;
        }

        lm->kp_enabled = true;
        err = device_create_file(&client->dev, &dev_attr_disable_kp);
        if (err < 0)
                goto fail2;

        idev->name = pdata->name ? : "LM8323 keypad";
        snprintf(lm->phys, sizeof(lm->phys),
                 "%s/input-kp", dev_name(&client->dev));
        idev->phys = lm->phys;

        idev->evbit[0] = BIT(EV_KEY) | BIT(EV_MSC);
        __set_bit(MSC_SCAN, idev->mscbit);
        for (i = 0; i < LM8323_KEYMAP_SIZE; i++) {
                __set_bit(pdata->keymap[i], idev->keybit);
                lm->keymap[i] = pdata->keymap[i];
        }
        __clear_bit(KEY_RESERVED, idev->keybit);

        if (pdata->repeat)
                __set_bit(EV_REP, idev->evbit);

        err = input_register_device(idev);
        if (err) {
                dev_dbg(&client->dev, "error registering input device\n");
                goto fail3;
        }

        err = request_irq(client->irq, lm8323_irq,
                          IRQF_TRIGGER_FALLING | IRQF_DISABLED,
                          "lm8323", lm);
        if (err) {
                dev_err(&client->dev, "could not get IRQ %d\n", client->irq);
                goto fail4;
        }

        device_init_wakeup(&client->dev, 1);
        enable_irq_wake(client->irq);

        return 0;

fail4:
        input_unregister_device(idev);
        idev = NULL;
fail3:
        device_remove_file(&client->dev, &dev_attr_disable_kp);
fail2:
        while (--i >= 0)
                if (lm->pwm[i].enabled)
                        led_classdev_unregister(&lm->pwm[i].cdev);
fail1:
        input_free_device(idev);
        kfree(lm);
        return err;
}

static int __devexit lm8323_remove(struct i2c_client *client)
{
        struct lm8323_chip *lm = i2c_get_clientdata(client);
        int i;

        disable_irq_wake(client->irq);
        free_irq(client->irq, lm);
        cancel_work_sync(&lm->work);

        input_unregister_device(lm->idev);

        device_remove_file(&lm->client->dev, &dev_attr_disable_kp);

        for (i = 0; i < 3; i++)
                if (lm->pwm[i].enabled)
                        led_classdev_unregister(&lm->pwm[i].cdev);

        kfree(lm);

        return 0;
}

#ifdef CONFIG_PM
/*
 * We don't need to explicitly suspend the chip, as it already switches off
 * when there's no activity.
 */
static int lm8323_suspend(struct i2c_client *client, pm_message_t mesg)
{
        struct lm8323_chip *lm = i2c_get_clientdata(client);
        int i;

        set_irq_wake(client->irq, 0);
        disable_irq(client->irq);

        mutex_lock(&lm->lock);
        lm->pm_suspend = true;
        mutex_unlock(&lm->lock);

        for (i = 0; i < 3; i++)
                if (lm->pwm[i].enabled)
                        led_classdev_suspend(&lm->pwm[i].cdev);

        return 0;
}

static int lm8323_resume(struct i2c_client *client)
{
        struct lm8323_chip *lm = i2c_get_clientdata(client);
        int i;

        mutex_lock(&lm->lock);
        lm->pm_suspend = false;
        mutex_unlock(&lm->lock);

        for (i = 0; i < 3; i++)
                if (lm->pwm[i].enabled)
                        led_classdev_resume(&lm->pwm[i].cdev);

        enable_irq(client->irq);
        set_irq_wake(client->irq, 1);

        return 0;
}
#else
#define lm8323_suspend  NULL
#define lm8323_resume   NULL
#endif

static const struct i2c_device_id lm8323_id[] = {
        { "lm8323", 0 },
        { }
};

static struct i2c_driver lm8323_i2c_driver = {
        .driver = {
                .name   = "lm8323",
        },
        .probe          = lm8323_probe,
        .remove         = __devexit_p(lm8323_remove),
        .suspend        = lm8323_suspend,
        .resume         = lm8323_resume,
        .id_table       = lm8323_id,
};
MODULE_DEVICE_TABLE(i2c, lm8323_id);

static int __init lm8323_init(void)
{
        return i2c_add_driver(&lm8323_i2c_driver);
}
module_init(lm8323_init);

static void __exit lm8323_exit(void)
{
        i2c_del_driver(&lm8323_i2c_driver);
}
module_exit(lm8323_exit);

MODULE_AUTHOR("Timo O. Karjalainen <timo.o.karjalainen@nokia.com>");
MODULE_AUTHOR("Daniel Stone");
MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
MODULE_DESCRIPTION("LM8323 keypad driver");
MODULE_LICENSE("GPL");