Input: introduce lm8323 keypad driver

lm8323 is the keypad driver used in n810 device.

[[e-mail]: coding-style fixes]
[[e-mail]: various cleanups]
Signed-off-by: Felipe Balbi <[e-mail]>
Reviewed-by: Trilok Soni <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/keyboard/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called jornada720_kbd.
 
+config KEYBOARD_LM8323
+	tristate "LM8323 keypad chip"
+	depends on I2C
+	depends on LEDS_CLASS
+	help
+	  If you say yes here you get support for the National Semiconductor
+	  LM8323 keypad controller.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called lm8323.
+
 config KEYBOARD_OMAP
 	tristate "TI OMAP keypad support"
 	depends on (ARCH_OMAP1 || ARCH_OMAP2)
···
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called sh_keysc.
-+
+
 config KEYBOARD_EP93XX
 	tristate "EP93xx Matrix Keypad support"
 	depends on ARCH_EP93XX

drivers/input/keyboard/Makefile

···
 obj-$(CONFIG_KEYBOARD_TOSA)		+= tosakbd.o
 obj-$(CONFIG_KEYBOARD_HIL)		+= hil_kbd.o
 obj-$(CONFIG_KEYBOARD_HIL_OLD)		+= hilkbd.o
+obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o
 obj-$(CONFIG_KEYBOARD_OMAP)		+= omap-keypad.o
 obj-$(CONFIG_KEYBOARD_PXA27x)		+= pxa27x_keypad.o
 obj-$(CONFIG_KEYBOARD_PXA930_ROTARY)	+= pxa930_rotary.o

drivers/input/keyboard/lm8323.c

···
+/*
+ * drivers/i2c/chips/lm8323.c
+ *
+ * Copyright (C) 2007-2009 Nokia Corporation
+ *
+ * Written by Daniel Stone <[e-mail]>
+ *            Timo O. Karjalainen <[e-mail]>
+ *
+ * Updated by Felipe Balbi <[e-mail]>
+ *
+ * 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 <[e-mail]>");
+MODULE_AUTHOR("Daniel Stone");
+MODULE_AUTHOR("Felipe Balbi <[e-mail]>");
+MODULE_DESCRIPTION("LM8323 keypad driver");
+MODULE_LICENSE("GPL");
+

include/linux/i2c/lm8323.h

···
+/*
+ * lm8323.h - Configuration for LM8323 keypad driver.
+ *
+ * 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
+ */
+
+#ifndef __LINUX_LM8323_H
+#define __LINUX_LM8323_H
+
+#include <linux/types.h>
+
+/*
+ * Largest keycode that the chip can send, plus one,
+ * so keys can be mapped directly at the index of the
+ * LM8323 keycode instead of subtracting one.
+ */
+#define LM8323_KEYMAP_SIZE	(0x7f + 1)
+
+#define LM8323_NUM_PWMS		3
+
+struct lm8323_platform_data {
+	int debounce_time; /* Time to watch for key bouncing, in ms. */
+	int active_time; /* Idle time until sleep, in ms. */
+
+	int size_x;
+	int size_y;
+	bool repeat;
+	const unsigned short *keymap;
+
+	const char *pwm_names[LM8323_NUM_PWMS];
+
+	const char *name; /* Device name. */
+};
+
+#endif /* __LINUX_LM8323_H */