LEDS: add BlinkM RGB LED driver, documentation and update MAINTAINERS

Add driver for BlinkM device to drivers/leds/.
Add entry to MAINTAINERS file.
Add documentation in Documentation/leds/.

A BlinkM is a RGB LED controlled through I2C.

This driver implements an interface to the LED framework
and another sysfs group to access the internal options
of the BlinkM.

rev6: Use module_i2c_driver().
rev5: Removed own workqueue in favor of events wq.
rev4: Fixed comments by Bryan Wu.
rev3: Fixed issues found by Jonathan Neuschäfer.

(bryan.wu@canonical.com: remove 2 trailing whitespace)

Signed-off-by: Jan-Simon Möller <jansimon.moeller@gmx.de>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

3 files changed, 821 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index f028f0348e83..f0aaf415316d 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -430,6 +430,14 @@ config LEDS_OT200
           This option enables support for the LEDs on the Bachmann OT200.
           Say Y to enable LEDs on the Bachmann OT200.
 
+config LEDS_BLINKM
+        tristate "LED support for the BlinkM I2C RGB LED"
+        depends on LEDS_CLASS
+        depends on I2C
+        help
+          This option enables support for the BlinkM RGB LED connected
+          through I2C. Say Y to enable support for the BlinkM LED.
+
 config LEDS_TRIGGERS
         bool "LED Trigger support"
         depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 5eebd7bce4be..d94d18f8a4be 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
 obj-$(CONFIG_LEDS_RENESAS_TPU)          += leds-renesas-tpu.o
 obj-$(CONFIG_LEDS_MAX8997)              += leds-max8997.o
 obj-$(CONFIG_LEDS_LM3556)               += leds-lm3556.o
+obj-$(CONFIG_LEDS_BLINKM)               += leds-blinkm.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)           += leds-dac124s085.o
diff --git a/drivers/leds/leds-blinkm.c b/drivers/leds/leds-blinkm.c
new file mode 100644
index 000000000000..5a9df43e5302
--- /dev/null
+++ b/drivers/leds/leds-blinkm.c
@@ -0,0 +1,812 @@
+/*
+ *  leds-blinkm.c
+ *  (c) Jan-Simon Möller (dl9pf@gmx.de)
+ *
+ *  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; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include <linux/printk.h>
+#include <linux/pm_runtime.h>
+#include <linux/leds.h>
+#include <linux/delay.h>
+
+/* Addresses to scan - BlinkM is on 0x09 by default*/
+static const unsigned short normal_i2c[] = { 0x09, I2C_CLIENT_END };
+
+static int blinkm_transfer_hw(struct i2c_client *client, int cmd);
+static int blinkm_test_run(struct i2c_client *client);
+
+struct blinkm_led {
+        struct i2c_client *i2c_client;
+        struct led_classdev led_cdev;
+        int id;
+        atomic_t active;
+};
+
+struct blinkm_work {
+        struct blinkm_led *blinkm_led;
+        struct work_struct work;
+};
+
+#define cdev_to_blmled(c)          container_of(c, struct blinkm_led, led_cdev)
+#define work_to_blmwork(c)         container_of(c, struct blinkm_work, work)
+
+struct blinkm_data {
+        struct i2c_client *i2c_client;
+        struct mutex update_lock;
+        /* used for led class interface */
+        struct blinkm_led blinkm_leds[3];
+        /* used for "blinkm" sysfs interface */
+        u8 red;                 /* color red */
+        u8 green;               /* color green */
+        u8 blue;                /* color blue */
+        /* next values to use for transfer */
+        u8 next_red;                    /* color red */
+        u8 next_green;          /* color green */
+        u8 next_blue;           /* color blue */
+        /* internal use */
+        u8 args[7];             /* set of args for transmission */
+        u8 i2c_addr;            /* i2c addr */
+        u8 fw_ver;              /* firmware version */
+        /* used, but not from userspace */
+        u8 hue;                 /* HSB  hue */
+        u8 saturation;          /* HSB  saturation */
+        u8 brightness;          /* HSB  brightness */
+        u8 next_hue;                    /* HSB  hue */
+        u8 next_saturation;             /* HSB  saturation */
+        u8 next_brightness;             /* HSB  brightness */
+        /* currently unused / todo */
+        u8 fade_speed;          /* fade speed     1 - 255 */
+        s8 time_adjust;         /* time adjust -128 - 127 */
+        u8 fade:1;              /* fade on = 1, off = 0 */
+        u8 rand:1;              /* rand fade mode on = 1 */
+        u8 script_id;           /* script ID */
+        u8 script_repeats;      /* repeats of script */
+        u8 script_startline;    /* line to start */
+};
+
+/* Colors */
+#define RED   0
+#define GREEN 1
+#define BLUE  2
+
+/* mapping command names to cmd chars - see datasheet */
+#define BLM_GO_RGB            0
+#define BLM_FADE_RGB          1
+#define BLM_FADE_HSB          2
+#define BLM_FADE_RAND_RGB     3
+#define BLM_FADE_RAND_HSB     4
+#define BLM_PLAY_SCRIPT       5
+#define BLM_STOP_SCRIPT       6
+#define BLM_SET_FADE_SPEED    7
+#define BLM_SET_TIME_ADJ      8
+#define BLM_GET_CUR_RGB       9
+#define BLM_WRITE_SCRIPT_LINE 10
+#define BLM_READ_SCRIPT_LINE  11
+#define BLM_SET_SCRIPT_LR     12        /* Length & Repeats */
+#define BLM_SET_ADDR          13
+#define BLM_GET_ADDR          14
+#define BLM_GET_FW_VER        15
+#define BLM_SET_STARTUP_PARAM 16
+
+/* BlinkM Commands
+ *  as extracted out of the datasheet:
+ *
+ *  cmdchar = command (ascii)
+ *  cmdbyte = command in hex
+ *  nr_args = number of arguments (to send)
+ *  nr_ret  = number of return values (to read)
+ *  dir = direction (0 = read, 1 = write, 2 = both)
+ *
+ */
+static const struct {
+        char cmdchar;
+        u8 cmdbyte;
+        u8 nr_args;
+        u8 nr_ret;
+        u8 dir:2;
+} blinkm_cmds[17] = {
+  /* cmdchar, cmdbyte, nr_args, nr_ret,  dir */
+        { 'n', 0x6e, 3, 0, 1},
+        { 'c', 0x63, 3, 0, 1},
+        { 'h', 0x68, 3, 0, 1},
+        { 'C', 0x43, 3, 0, 1},
+        { 'H', 0x48, 3, 0, 1},
+        { 'p', 0x70, 3, 0, 1},
+        { 'o', 0x6f, 0, 0, 1},
+        { 'f', 0x66, 1, 0, 1},
+        { 't', 0x74, 1, 0, 1},
+        { 'g', 0x67, 0, 3, 0},
+        { 'W', 0x57, 7, 0, 1},
+        { 'R', 0x52, 2, 5, 2},
+        { 'L', 0x4c, 3, 0, 1},
+        { 'A', 0x41, 4, 0, 1},
+        { 'a', 0x61, 0, 1, 0},
+        { 'Z', 0x5a, 0, 1, 0},
+        { 'B', 0x42, 5, 0, 1},
+};
+
+static ssize_t show_color_common(struct device *dev, char *buf, int color)
+{
+        struct i2c_client *client;
+        struct blinkm_data *data;
+        int ret;
+
+        client = to_i2c_client(dev);
+        data = i2c_get_clientdata(client);
+
+        ret = blinkm_transfer_hw(client, BLM_GET_CUR_RGB);
+        if (ret < 0)
+                return ret;
+        switch (color) {
+        case RED:
+                return scnprintf(buf, PAGE_SIZE, "%02X\n", data->red);
+                break;
+        case GREEN:
+                return scnprintf(buf, PAGE_SIZE, "%02X\n", data->green);
+                break;
+        case BLUE:
+                return scnprintf(buf, PAGE_SIZE, "%02X\n", data->blue);
+                break;
+        default:
+                return -EINVAL;
+        }
+        return -EINVAL;
+}
+
+static int store_color_common(struct device *dev, const char *buf, int color)
+{
+        struct i2c_client *client;
+        struct blinkm_data *data;
+        int ret;
+        u8 value;
+
+        client = to_i2c_client(dev);
+        data = i2c_get_clientdata(client);
+
+        ret = kstrtou8(buf, 10, &value);
+        if (ret < 0) {
+                dev_err(dev, "BlinkM: value too large!\n");
+                return ret;
+        }
+
+        switch (color) {
+        case RED:
+                data->next_red = value;
+                break;
+        case GREEN:
+                data->next_green = value;
+                break;
+        case BLUE:
+                data->next_blue = value;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        dev_dbg(dev, "next_red = %d, next_green = %d, next_blue = %d\n",
+                        data->next_red, data->next_green, data->next_blue);
+
+        /* if mode ... */
+        ret = blinkm_transfer_hw(client, BLM_GO_RGB);
+        if (ret < 0) {
+                dev_err(dev, "BlinkM: can't set RGB\n");
+                return ret;
+        }
+        return 0;
+}
+
+static ssize_t show_red(struct device *dev, struct device_attribute *attr,
+                        char *buf)
+{
+        return show_color_common(dev, buf, RED);
+}
+
+static ssize_t store_red(struct device *dev, struct device_attribute *attr,
+                         const char *buf, size_t count)
+{
+        int ret;
+
+        ret = store_color_common(dev, buf, RED);
+        if (ret < 0)
+                return ret;
+        return count;
+}
+
+static DEVICE_ATTR(red, S_IRUGO | S_IWUSR, show_red, store_red);
+
+static ssize_t show_green(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        return show_color_common(dev, buf, GREEN);
+}
+
+static ssize_t store_green(struct device *dev, struct device_attribute *attr,
+                           const char *buf, size_t count)
+{
+
+        int ret;
+
+        ret = store_color_common(dev, buf, GREEN);
+        if (ret < 0)
+                return ret;
+        return count;
+}
+
+static DEVICE_ATTR(green, S_IRUGO | S_IWUSR, show_green, store_green);
+
+static ssize_t show_blue(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        return show_color_common(dev, buf, BLUE);
+}
+
+static ssize_t store_blue(struct device *dev, struct device_attribute *attr,
+                          const char *buf, size_t count)
+{
+        int ret;
+
+        ret = store_color_common(dev, buf, BLUE);
+        if (ret < 0)
+                return ret;
+        return count;
+}
+
+static DEVICE_ATTR(blue, S_IRUGO | S_IWUSR, show_blue, store_blue);
+
+static ssize_t show_test(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        return scnprintf(buf, PAGE_SIZE,
+                         "#Write into test to start test sequence!#\n");
+}
+
+static ssize_t store_test(struct device *dev, struct device_attribute *attr,
+                          const char *buf, size_t count)
+{
+
+        struct i2c_client *client;
+        int ret;
+        client = to_i2c_client(dev);
+
+        /*test */
+        ret = blinkm_test_run(client);
+        if (ret < 0)
+                return ret;
+
+        return count;
+}
+
+static DEVICE_ATTR(test, S_IRUGO | S_IWUSR, show_test, store_test);
+
+/* TODO: HSB, fade, timeadj, script ... */
+
+static struct attribute *blinkm_attrs[] = {
+        &dev_attr_red.attr,
+        &dev_attr_green.attr,
+        &dev_attr_blue.attr,
+        &dev_attr_test.attr,
+        NULL,
+};
+
+static struct attribute_group blinkm_group = {
+        .name = "blinkm",
+        .attrs = blinkm_attrs,
+};
+
+static int blinkm_write(struct i2c_client *client, int cmd, u8 *arg)
+{
+        int result;
+        int i;
+        int arglen = blinkm_cmds[cmd].nr_args;
+        /* write out cmd to blinkm - always / default step */
+        result = i2c_smbus_write_byte(client, blinkm_cmds[cmd].cmdbyte);
+        if (result < 0)
+                return result;
+        /* no args to write out */
+        if (arglen == 0)
+                return 0;
+
+        for (i = 0; i < arglen; i++) {
+                /* repeat for arglen */
+                result = i2c_smbus_write_byte(client, arg[i]);
+                if (result < 0)
+                        return result;
+        }
+        return 0;
+}
+
+static int blinkm_read(struct i2c_client *client, int cmd, u8 *arg)
+{
+        int result;
+        int i;
+        int retlen = blinkm_cmds[cmd].nr_ret;
+        for (i = 0; i < retlen; i++) {
+                /* repeat for retlen */
+                result = i2c_smbus_read_byte(client);
+                if (result < 0)
+                        return result;
+                arg[i] = result;
+        }
+
+        return 0;
+}
+
+static int blinkm_transfer_hw(struct i2c_client *client, int cmd)
+{
+        /* the protocol is simple but non-standard:
+         * e.g.  cmd 'g' (= 0x67) for "get device address"
+         * - which defaults to 0x09 - would be the sequence:
+         *   a) write 0x67 to the device (byte write)
+         *   b) read the value (0x09) back right after (byte read)
+         *
+         * Watch out for "unfinished" sequences (i.e. not enough reads
+         * or writes after a command. It will make the blinkM misbehave.
+         * Sequence is key here.
+         */
+
+        /* args / return are in private data struct */
+        struct blinkm_data *data = i2c_get_clientdata(client);
+
+        /* We start hardware transfers which are not to be
+         * mixed with other commands. Aquire a lock now. */
+        if (mutex_lock_interruptible(&data->update_lock) < 0)
+                return -EAGAIN;
+
+        /* switch cmd - usually write before reads */
+        switch (cmd) {
+        case BLM_FADE_RAND_RGB:
+        case BLM_GO_RGB:
+        case BLM_FADE_RGB:
+                data->args[0] = data->next_red;
+                data->args[1] = data->next_green;
+                data->args[2] = data->next_blue;
+                blinkm_write(client, cmd, data->args);
+                data->red = data->args[0];
+                data->green = data->args[1];
+                data->blue = data->args[2];
+                break;
+        case BLM_FADE_HSB:
+        case BLM_FADE_RAND_HSB:
+                data->args[0] = data->next_hue;
+                data->args[1] = data->next_saturation;
+                data->args[2] = data->next_brightness;
+                blinkm_write(client, cmd, data->args);
+                data->hue = data->next_hue;
+                data->saturation = data->next_saturation;
+                data->brightness = data->next_brightness;
+                break;
+        case BLM_PLAY_SCRIPT:
+                data->args[0] = data->script_id;
+                data->args[1] = data->script_repeats;
+                data->args[2] = data->script_startline;
+                blinkm_write(client, cmd, data->args);
+                break;
+        case BLM_STOP_SCRIPT:
+                blinkm_write(client, cmd, NULL);
+                break;
+        case BLM_GET_CUR_RGB:
+                data->args[0] = data->red;
+                data->args[1] = data->green;
+                data->args[2] = data->blue;
+                blinkm_write(client, cmd, NULL);
+                blinkm_read(client, cmd, data->args);
+                data->red = data->args[0];
+                data->green = data->args[1];
+                data->blue = data->args[2];
+                break;
+        case BLM_GET_ADDR:
+                data->args[0] = data->i2c_addr;
+                blinkm_write(client, cmd, NULL);
+                blinkm_read(client, cmd, data->args);
+                data->i2c_addr = data->args[0];
+                break;
+        case BLM_SET_TIME_ADJ:
+        case BLM_SET_FADE_SPEED:
+        case BLM_READ_SCRIPT_LINE:
+        case BLM_WRITE_SCRIPT_LINE:
+        case BLM_SET_SCRIPT_LR:
+        case BLM_SET_ADDR:
+        case BLM_GET_FW_VER:
+        case BLM_SET_STARTUP_PARAM:
+                dev_err(&client->dev,
+                                "BlinkM: cmd %d not implemented yet.\n", cmd);
+                break;
+        default:
+                dev_err(&client->dev, "BlinkM: unknown command %d\n", cmd);
+                mutex_unlock(&data->update_lock);
+                return -EINVAL;
+        }                       /* end switch(cmd) */
+
+        /* transfers done, unlock */
+        mutex_unlock(&data->update_lock);
+        return 0;
+}
+
+static void led_work(struct work_struct *work)
+{
+        int ret;
+        struct blinkm_led *led;
+        struct blinkm_data *data ;
+        struct blinkm_work *blm_work = work_to_blmwork(work);
+
+        led = blm_work->blinkm_led;
+        data = i2c_get_clientdata(led->i2c_client);
+        ret = blinkm_transfer_hw(led->i2c_client, BLM_GO_RGB);
+        atomic_dec(&led->active);
+        dev_dbg(&led->i2c_client->dev,
+                        "# DONE # next_red = %d, next_green = %d,"
+                        " next_blue = %d, active = %d\n",
+                        data->next_red, data->next_green,
+                        data->next_blue, atomic_read(&led->active));
+        kfree(blm_work);
+}
+
+static int blinkm_led_common_set(struct led_classdev *led_cdev,
+                                 enum led_brightness value, int color)
+{
+        /* led_brightness is 0, 127 or 255 - we just use it here as-is */
+        struct blinkm_led *led = cdev_to_blmled(led_cdev);
+        struct blinkm_data *data = i2c_get_clientdata(led->i2c_client);
+        struct blinkm_work *bl_work = kzalloc(sizeof(struct blinkm_work),
+                                              GFP_ATOMIC);
+
+        switch (color) {
+        case RED:
+                /* bail out if there's no change */
+                if (data->next_red == (u8) value)
+                        return 0;
+                /* we assume a quite fast sequence here ([off]->on->off)
+                 * think of network led trigger - we cannot blink that fast, so
+                 * in case we already have a off->on->off transition queued up,
+                 * we refuse to queue up more.
+                 * Revisit: fast-changing brightness. */
+                if (atomic_read(&led->active) > 1)
+                        return 0;
+                data->next_red = (u8) value;
+                break;
+        case GREEN:
+                /* bail out if there's no change */
+                if (data->next_green == (u8) value)
+                        return 0;
+                /* we assume a quite fast sequence here ([off]->on->off)
+                 * Revisit: fast-changing brightness. */
+                if (atomic_read(&led->active) > 1)
+                        return 0;
+                data->next_green = (u8) value;
+                break;
+        case BLUE:
+                /* bail out if there's no change */
+                if (data->next_blue == (u8) value)
+                        return 0;
+                /* we assume a quite fast sequence here ([off]->on->off)
+                 * Revisit: fast-changing brightness. */
+                if (atomic_read(&led->active) > 1)
+                        return 0;
+                data->next_blue = (u8) value;
+                break;
+
+        default:
+                dev_err(&led->i2c_client->dev, "BlinkM: unknown color.\n");
+                return -EINVAL;
+        }
+
+        atomic_inc(&led->active);
+        dev_dbg(&led->i2c_client->dev,
+                        "#TO_SCHED# next_red = %d, next_green = %d,"
+                        " next_blue = %d, active = %d\n",
+                        data->next_red, data->next_green,
+                        data->next_blue, atomic_read(&led->active));
+
+        /* a fresh work _item_ for each change */
+        bl_work->blinkm_led = led;
+        INIT_WORK(&bl_work->work, led_work);
+        /* queue work in own queue for easy sync on exit*/
+        schedule_work(&bl_work->work);
+
+        return 0;
+}
+
+static void blinkm_led_red_set(struct led_classdev *led_cdev,
+                               enum led_brightness value)
+{
+        blinkm_led_common_set(led_cdev, value, RED);
+}
+
+static void blinkm_led_green_set(struct led_classdev *led_cdev,
+                                 enum led_brightness value)
+{
+        blinkm_led_common_set(led_cdev, value, GREEN);
+}
+
+static void blinkm_led_blue_set(struct led_classdev *led_cdev,
+                                enum led_brightness value)
+{
+        blinkm_led_common_set(led_cdev, value, BLUE);
+}
+
+static void blinkm_init_hw(struct i2c_client *client)
+{
+        int ret;
+        ret = blinkm_transfer_hw(client, BLM_STOP_SCRIPT);
+        ret = blinkm_transfer_hw(client, BLM_GO_RGB);
+}
+
+static int blinkm_test_run(struct i2c_client *client)
+{
+        int ret;
+        struct blinkm_data *data = i2c_get_clientdata(client);
+
+        data->next_red = 0x01;
+        data->next_green = 0x05;
+        data->next_blue = 0x10;
+        ret = blinkm_transfer_hw(client, BLM_GO_RGB);
+        if (ret < 0)
+                return ret;
+        msleep(2000);
+
+        data->next_red = 0x25;
+        data->next_green = 0x10;
+        data->next_blue = 0x31;
+        ret = blinkm_transfer_hw(client, BLM_FADE_RGB);
+        if (ret < 0)
+                return ret;
+        msleep(2000);
+
+        data->next_hue = 0x50;
+        data->next_saturation = 0x10;
+        data->next_brightness = 0x20;
+        ret = blinkm_transfer_hw(client, BLM_FADE_HSB);
+        if (ret < 0)
+                return ret;
+        msleep(2000);
+
+        return 0;
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int blinkm_detect(struct i2c_client *client, struct i2c_board_info *info)
+{
+        struct i2c_adapter *adapter = client->adapter;
+        int ret;
+        int count = 99;
+        u8 tmpargs[7];
+
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+                                     | I2C_FUNC_SMBUS_WORD_DATA
+                                     | I2C_FUNC_SMBUS_WRITE_BYTE))
+                return -ENODEV;
+
+        /* Now, we do the remaining detection. Simple for now. */
+        /* We might need more guards to protect other i2c slaves */
+
+        /* make sure the blinkM is balanced (read/writes) */
+        while (count > 0) {
+                ret = blinkm_write(client, BLM_GET_ADDR, NULL);
+                usleep_range(5000, 10000);
+                ret = blinkm_read(client, BLM_GET_ADDR, tmpargs);
+                usleep_range(5000, 10000);
+                if (tmpargs[0] == 0x09)
+                        count = 0;
+                count--;
+        }
+
+        /* Step 1: Read BlinkM address back  -  cmd_char 'a' */
+        ret = blinkm_write(client, BLM_GET_ADDR, NULL);
+        if (ret < 0)
+                return -ENODEV;
+        usleep_range(20000, 30000);     /* allow a small delay */
+        ret = blinkm_read(client, BLM_GET_ADDR, tmpargs);
+        if (ret < 0)
+                return -ENODEV;
+
+        if (tmpargs[0] != 0x09) {
+                dev_err(&client->dev, "enodev DEV ADDR = 0x%02X\n", tmpargs[0]);
+                return -ENODEV;
+        }
+
+        strlcpy(info->type, "blinkm", I2C_NAME_SIZE);
+        return 0;
+}
+
+static int __devinit blinkm_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+        struct blinkm_data *data;
+        struct blinkm_led *led[3];
+        int err, i;
+        char blinkm_led_name[28];
+
+        data = devm_kzalloc(&client->dev,
+                        sizeof(struct blinkm_data), GFP_KERNEL);
+        if (!data) {
+                err = -ENOMEM;
+                goto exit;
+        }
+
+        data->i2c_addr = 0x09;
+        data->i2c_addr = 0x08;
+        /* i2c addr  - use fake addr of 0x08 initially (real is 0x09) */
+        data->fw_ver = 0xfe;
+        /* firmware version - use fake until we read real value
+         * (currently broken - BlinkM confused!) */
+        data->script_id = 0x01;
+        data->i2c_client = client;
+
+        i2c_set_clientdata(client, data);
+        mutex_init(&data->update_lock);
+
+        /* Register sysfs hooks */
+        err = sysfs_create_group(&client->dev.kobj, &blinkm_group);
+        if (err < 0) {
+                dev_err(&client->dev, "couldn't register sysfs group\n");
+                goto exit;
+        }
+
+        for (i = 0; i < 3; i++) {
+                /* RED = 0, GREEN = 1, BLUE = 2 */
+                led[i] = &data->blinkm_leds[i];
+                led[i]->i2c_client = client;
+                led[i]->id = i;
+                led[i]->led_cdev.max_brightness = 255;
+                led[i]->led_cdev.flags = LED_CORE_SUSPENDRESUME;
+                atomic_set(&led[i]->active, 0);
+                switch (i) {
+                case RED:
+                        snprintf(blinkm_led_name, sizeof(blinkm_led_name),
+                                         "blinkm-%d-%d-red",
+                                         client->adapter->nr,
+                                         client->addr);
+                        led[i]->led_cdev.name = blinkm_led_name;
+                        led[i]->led_cdev.brightness_set = blinkm_led_red_set;
+                        err = led_classdev_register(&client->dev,
+                                                    &led[i]->led_cdev);
+                        if (err < 0) {
+                                dev_err(&client->dev,
+                                        "couldn't register LED %s\n",
+                                        led[i]->led_cdev.name);
+                                goto failred;
+                        }
+                        break;
+                case GREEN:
+                        snprintf(blinkm_led_name, sizeof(blinkm_led_name),
+                                         "blinkm-%d-%d-green",
+                                         client->adapter->nr,
+                                         client->addr);
+                        led[i]->led_cdev.name = blinkm_led_name;
+                        led[i]->led_cdev.brightness_set = blinkm_led_green_set;
+                        err = led_classdev_register(&client->dev,
+                                                    &led[i]->led_cdev);
+                        if (err < 0) {
+                                dev_err(&client->dev,
+                                        "couldn't register LED %s\n",
+                                        led[i]->led_cdev.name);
+                                goto failgreen;
+                        }
+                        break;
+                case BLUE:
+                        snprintf(blinkm_led_name, sizeof(blinkm_led_name),
+                                         "blinkm-%d-%d-blue",
+                                         client->adapter->nr,
+                                         client->addr);
+                        led[i]->led_cdev.name = blinkm_led_name;
+                        led[i]->led_cdev.brightness_set = blinkm_led_blue_set;
+                        err = led_classdev_register(&client->dev,
+                                                    &led[i]->led_cdev);
+                        if (err < 0) {
+                                dev_err(&client->dev,
+                                        "couldn't register LED %s\n",
+                                        led[i]->led_cdev.name);
+                                goto failblue;
+                        }
+                        break;
+                }               /* end switch */
+        }                       /* end for */
+
+        /* Initialize the blinkm */
+        blinkm_init_hw(client);
+
+        return 0;
+
+failblue:
+        led_classdev_unregister(&led[GREEN]->led_cdev);
+
+failgreen:
+        led_classdev_unregister(&led[RED]->led_cdev);
+
+failred:
+        sysfs_remove_group(&client->dev.kobj, &blinkm_group);
+exit:
+        return err;
+}
+
+static int __devexit blinkm_remove(struct i2c_client *client)
+{
+        struct blinkm_data *data = i2c_get_clientdata(client);
+        int ret = 0;
+        int i;
+
+        /* make sure no workqueue entries are pending */
+        for (i = 0; i < 3; i++) {
+                flush_scheduled_work();
+                led_classdev_unregister(&data->blinkm_leds[i].led_cdev);
+        }
+
+        /* reset rgb */
+        data->next_red = 0x00;
+        data->next_green = 0x00;
+        data->next_blue = 0x00;
+        ret = blinkm_transfer_hw(client, BLM_FADE_RGB);
+        if (ret < 0)
+                dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
+
+        /* reset hsb */
+        data->next_hue = 0x00;
+        data->next_saturation = 0x00;
+        data->next_brightness = 0x00;
+        ret = blinkm_transfer_hw(client, BLM_FADE_HSB);
+        if (ret < 0)
+                dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
+
+        /* red fade to off */
+        data->next_red = 0xff;
+        ret = blinkm_transfer_hw(client, BLM_GO_RGB);
+        if (ret < 0)
+                dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
+
+        /* off */
+        data->next_red = 0x00;
+        ret = blinkm_transfer_hw(client, BLM_FADE_RGB);
+        if (ret < 0)
+                dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
+
+        sysfs_remove_group(&client->dev.kobj, &blinkm_group);
+        return 0;
+}
+
+static const struct i2c_device_id blinkm_id[] = {
+        {"blinkm", 0},
+        {}
+};
+
+MODULE_DEVICE_TABLE(i2c, blinkm_id);
+
+  /* This is the driver that will be inserted */
+static struct i2c_driver blinkm_driver = {
+        .class = I2C_CLASS_HWMON,
+        .driver = {
+                   .name = "blinkm",
+                   },
+        .probe = blinkm_probe,
+        .remove = __devexit_p(blinkm_remove),
+        .id_table = blinkm_id,
+        .detect = blinkm_detect,
+        .address_list = normal_i2c,
+};
+
+module_i2c_driver(blinkm_driver);
+
+MODULE_AUTHOR("Jan-Simon Moeller <dl9pf@gmx.de>");
+MODULE_DESCRIPTION("BlinkM RGB LED driver");
+MODULE_LICENSE("GPL");
+