leds: driver for National Semiconductor LP5521 chip
authorSamu Onkalo <samu.p.onkalo@nokia.com>
Thu, 11 Nov 2010 22:05:22 +0000 (14:05 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 12 Nov 2010 15:55:32 +0000 (07:55 -0800)
This patchset provides support for LP5521 and LP5523 LED driver chips from
National Semicondutor.  Both drivers supports programmable engines and
naturally LED class features.

Documentation is provided as a part of the patchset.  I created "leds"
subdirectory under Documentation.  Perhaps the rest of the leds*
documentation should be moved there.

Datasheets are freely available at National Semiconductor www pages.

This patch:

LP5521 chip is three channel led driver with programmable engines.  Driver
provides support for that chip for direct access via led class or via
programmable engines.

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/leds/leds-lp5521.c [new file with mode: 0644]
include/linux/leds-lp5521.h [new file with mode: 0644]

diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
new file mode 100644 (file)
index 0000000..3782f31
--- /dev/null
@@ -0,0 +1,821 @@
+/*
+ * LP5521 LED chip driver.
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/ctype.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/leds.h>
+#include <linux/leds-lp5521.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+
+#define LP5521_PROGRAM_LENGTH          32      /* in bytes */
+
+#define LP5521_MAX_LEDS                        3       /* Maximum number of LEDs */
+#define LP5521_MAX_ENGINES             3       /* Maximum number of engines */
+
+#define LP5521_ENG_MASK_BASE           0x30    /* 00110000 */
+#define LP5521_ENG_STATUS_MASK         0x07    /* 00000111 */
+
+#define LP5521_CMD_LOAD                        0x15    /* 00010101 */
+#define LP5521_CMD_RUN                 0x2a    /* 00101010 */
+#define LP5521_CMD_DIRECT              0x3f    /* 00111111 */
+#define LP5521_CMD_DISABLED            0x00    /* 00000000 */
+
+/* Registers */
+#define LP5521_REG_ENABLE              0x00
+#define LP5521_REG_OP_MODE             0x01
+#define LP5521_REG_R_PWM               0x02
+#define LP5521_REG_G_PWM               0x03
+#define LP5521_REG_B_PWM               0x04
+#define LP5521_REG_R_CURRENT           0x05
+#define LP5521_REG_G_CURRENT           0x06
+#define LP5521_REG_B_CURRENT           0x07
+#define LP5521_REG_CONFIG              0x08
+#define LP5521_REG_R_CHANNEL_PC                0x09
+#define LP5521_REG_G_CHANNEL_PC                0x0A
+#define LP5521_REG_B_CHANNEL_PC                0x0B
+#define LP5521_REG_STATUS              0x0C
+#define LP5521_REG_RESET               0x0D
+#define LP5521_REG_GPO                 0x0E
+#define LP5521_REG_R_PROG_MEM          0x10
+#define LP5521_REG_G_PROG_MEM          0x30
+#define LP5521_REG_B_PROG_MEM          0x50
+
+#define LP5521_PROG_MEM_BASE           LP5521_REG_R_PROG_MEM
+#define LP5521_PROG_MEM_SIZE           0x20
+
+/* Base register to set LED current */
+#define LP5521_REG_LED_CURRENT_BASE    LP5521_REG_R_CURRENT
+
+/* Base register to set the brightness */
+#define LP5521_REG_LED_PWM_BASE                LP5521_REG_R_PWM
+
+/* Bits in ENABLE register */
+#define LP5521_MASTER_ENABLE           0x40    /* Chip master enable */
+#define LP5521_LOGARITHMIC_PWM         0x80    /* Logarithmic PWM adjustment */
+#define LP5521_EXEC_RUN                        0x2A
+
+/* Bits in CONFIG register */
+#define LP5521_PWM_HF                  0x40    /* PWM: 0 = 256Hz, 1 = 558Hz */
+#define LP5521_PWRSAVE_EN              0x20    /* 1 = Power save mode */
+#define LP5521_CP_MODE_OFF             0       /* Charge pump (CP) off */
+#define LP5521_CP_MODE_BYPASS          8       /* CP forced to bypass mode */
+#define LP5521_CP_MODE_1X5             0x10    /* CP forced to 1.5x mode */
+#define LP5521_CP_MODE_AUTO            0x18    /* Automatic mode selection */
+#define LP5521_R_TO_BATT               4       /* R out: 0 = CP, 1 = Vbat */
+#define LP5521_CLK_SRC_EXT             0       /* Ext-clk source (CLK_32K) */
+#define LP5521_CLK_INT                 1       /* Internal clock */
+#define LP5521_CLK_AUTO                        2       /* Automatic clock selection */
+
+/* Status */
+#define LP5521_EXT_CLK_USED            0x08
+
+struct lp5521_engine {
+       const struct attribute_group *attributes;
+       int             id;
+       u8              mode;
+       u8              prog_page;
+       u8              engine_mask;
+};
+
+struct lp5521_led {
+       int                     id;
+       u8                      chan_nr;
+       u8                      led_current;
+       u8                      max_current;
+       struct led_classdev     cdev;
+       struct work_struct      brightness_work;
+       u8                      brightness;
+};
+
+struct lp5521_chip {
+       struct lp5521_platform_data *pdata;
+       struct mutex            lock; /* Serialize control */
+       struct i2c_client       *client;
+       struct lp5521_engine    engines[LP5521_MAX_ENGINES];
+       struct lp5521_led       leds[LP5521_MAX_LEDS];
+       u8                      num_channels;
+       u8                      num_leds;
+};
+
+#define cdev_to_led(c)         container_of(c, struct lp5521_led, cdev)
+#define engine_to_lp5521(eng)  container_of((eng), struct lp5521_chip, \
+                                               engines[(eng)->id - 1])
+#define led_to_lp5521(led)     container_of((led), struct lp5521_chip, \
+                                               leds[(led)->id])
+
+static void lp5521_led_brightness_work(struct work_struct *work);
+
+static inline int lp5521_write(struct i2c_client *client, u8 reg, u8 value)
+{
+       return i2c_smbus_write_byte_data(client, reg, value);
+}
+
+static int lp5521_read(struct i2c_client *client, u8 reg, u8 *buf)
+{
+       s32 ret;
+
+       ret = i2c_smbus_read_byte_data(client, reg);
+       if (ret < 0)
+               return -EIO;
+
+       *buf = ret;
+       return 0;
+}
+
+static int lp5521_set_engine_mode(struct lp5521_engine *engine, u8 mode)
+{
+       struct lp5521_chip *chip = engine_to_lp5521(engine);
+       struct i2c_client *client = chip->client;
+       int ret;
+       u8 engine_state;
+
+       /* Only transition between RUN and DIRECT mode are handled here */
+       if (mode == LP5521_CMD_LOAD)
+               return 0;
+
+       if (mode == LP5521_CMD_DISABLED)
+               mode = LP5521_CMD_DIRECT;
+
+       ret = lp5521_read(client, LP5521_REG_OP_MODE, &engine_state);
+
+       /* set mode only for this engine */
+       engine_state &= ~(engine->engine_mask);
+       mode &= engine->engine_mask;
+       engine_state |= mode;
+       ret |= lp5521_write(client, LP5521_REG_OP_MODE, engine_state);
+
+       return ret;
+}
+
+static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)
+{
+       struct lp5521_chip *chip = engine_to_lp5521(eng);
+       struct i2c_client *client = chip->client;
+       int ret;
+       int addr;
+       u8 mode;
+
+       /* move current engine to direct mode and remember the state */
+       ret = lp5521_set_engine_mode(eng, LP5521_CMD_DIRECT);
+       usleep_range(1000, 10000);
+       ret |= lp5521_read(client, LP5521_REG_OP_MODE, &mode);
+
+       /* For loading, all the engines to load mode */
+       lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
+       usleep_range(1000, 10000);
+       lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_LOAD);
+       usleep_range(1000, 10000);
+
+       addr = LP5521_PROG_MEM_BASE + eng->prog_page * LP5521_PROG_MEM_SIZE;
+       i2c_smbus_write_i2c_block_data(client,
+                               addr,
+                               LP5521_PROG_MEM_SIZE,
+                               pattern);
+
+       ret |= lp5521_write(client, LP5521_REG_OP_MODE, mode);
+       return ret;
+}
+
+static int lp5521_set_led_current(struct lp5521_chip *chip, int led, u8 curr)
+{
+       return lp5521_write(chip->client,
+                   LP5521_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
+                   curr);
+}
+
+static void lp5521_init_engine(struct lp5521_chip *chip,
+                       const struct attribute_group *attr_group)
+{
+       int i;
+       for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
+               chip->engines[i].id = i + 1;
+               chip->engines[i].engine_mask = LP5521_ENG_MASK_BASE >> (i * 2);
+               chip->engines[i].prog_page = i;
+               chip->engines[i].attributes = &attr_group[i];
+       }
+}
+
+static int lp5521_configure(struct i2c_client *client,
+                       const struct attribute_group *attr_group)
+{
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       int ret;
+
+       lp5521_init_engine(chip, attr_group);
+
+       lp5521_write(client, LP5521_REG_RESET, 0xff);
+
+       usleep_range(10000, 20000);
+
+       /* Set all PWMs to direct control mode */
+       ret = lp5521_write(client, LP5521_REG_OP_MODE, 0x3F);
+
+       /* Enable auto-powersave, set charge pump to auto, red to battery */
+       ret |= lp5521_write(client, LP5521_REG_CONFIG,
+               LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT);
+
+       /* Initialize all channels PWM to zero -> leds off */
+       ret |= lp5521_write(client, LP5521_REG_R_PWM, 0);
+       ret |= lp5521_write(client, LP5521_REG_G_PWM, 0);
+       ret |= lp5521_write(client, LP5521_REG_B_PWM, 0);
+
+       /* Set engines are set to run state when OP_MODE enables engines */
+       ret |= lp5521_write(client, LP5521_REG_ENABLE,
+                       LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM |
+                       LP5521_EXEC_RUN);
+       /* enable takes 500us */
+       usleep_range(500, 20000);
+
+       return ret;
+}
+
+static int lp5521_run_selftest(struct lp5521_chip *chip, char *buf)
+{
+       int ret;
+       u8 status;
+
+       ret = lp5521_read(chip->client, LP5521_REG_STATUS, &status);
+       if (ret < 0)
+               return ret;
+
+       /* Check that ext clock is really in use if requested */
+       if (chip->pdata && chip->pdata->clock_mode == LP5521_CLOCK_EXT)
+               if  ((status & LP5521_EXT_CLK_USED) == 0)
+                       return -EIO;
+       return 0;
+}
+
+static void lp5521_set_brightness(struct led_classdev *cdev,
+                            enum led_brightness brightness)
+{
+       struct lp5521_led *led = cdev_to_led(cdev);
+       led->brightness = (u8)brightness;
+       schedule_work(&led->brightness_work);
+}
+
+static void lp5521_led_brightness_work(struct work_struct *work)
+{
+       struct lp5521_led *led = container_of(work,
+                                             struct lp5521_led,
+                                             brightness_work);
+       struct lp5521_chip *chip = led_to_lp5521(led);
+       struct i2c_client *client = chip->client;
+
+       mutex_lock(&chip->lock);
+       lp5521_write(client, LP5521_REG_LED_PWM_BASE + led->chan_nr,
+               led->brightness);
+       mutex_unlock(&chip->lock);
+}
+
+/* Detect the chip by setting its ENABLE register and reading it back. */
+static int lp5521_detect(struct i2c_client *client)
+{
+       int ret;
+       u8 buf;
+
+       ret = lp5521_write(client, LP5521_REG_ENABLE,
+                       LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM);
+       if (ret)
+               return ret;
+       usleep_range(1000, 10000);
+       ret = lp5521_read(client, LP5521_REG_ENABLE, &buf);
+       if (ret)
+               return ret;
+       if (buf != (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM))
+               return -ENODEV;
+
+       return 0;
+}
+
+/* Set engine mode and create appropriate sysfs attributes, if required. */
+static int lp5521_set_mode(struct lp5521_engine *engine, u8 mode)
+{
+       struct lp5521_chip *chip = engine_to_lp5521(engine);
+       struct i2c_client *client = chip->client;
+       struct device *dev = &client->dev;
+       int ret = 0;
+
+       /* if in that mode already do nothing, except for run */
+       if (mode == engine->mode && mode != LP5521_CMD_RUN)
+               return 0;
+
+       if (mode == LP5521_CMD_RUN) {
+               ret = lp5521_set_engine_mode(engine, LP5521_CMD_RUN);
+       } else if (mode == LP5521_CMD_LOAD) {
+               lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
+               lp5521_set_engine_mode(engine, LP5521_CMD_LOAD);
+
+               ret = sysfs_create_group(&dev->kobj, engine->attributes);
+               if (ret)
+                       return ret;
+       } else if (mode == LP5521_CMD_DISABLED) {
+               lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
+       }
+
+       /* remove load attribute from sysfs if not in load mode */
+       if (engine->mode == LP5521_CMD_LOAD && mode != LP5521_CMD_LOAD)
+               sysfs_remove_group(&dev->kobj, engine->attributes);
+
+       engine->mode = mode;
+
+       return ret;
+}
+
+static int lp5521_do_store_load(struct lp5521_engine *engine,
+                               const char *buf, size_t len)
+{
+       struct lp5521_chip *chip = engine_to_lp5521(engine);
+       struct i2c_client *client = chip->client;
+       int  ret, nrchars, offset = 0, i = 0;
+       char c[3];
+       unsigned cmd;
+       u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
+
+       while ((offset < len - 1) && (i < LP5521_PROGRAM_LENGTH)) {
+               /* separate sscanfs because length is working only for %s */
+               ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
+               ret = sscanf(c, "%2x", &cmd);
+               if (ret != 1)
+                       goto fail;
+               pattern[i] = (u8)cmd;
+
+               offset += nrchars;
+               i++;
+       }
+
+       /* Each instruction is 16bit long. Check that length is even */
+       if (i % 2)
+               goto fail;
+
+       mutex_lock(&chip->lock);
+       ret = lp5521_load_program(engine, pattern);
+       mutex_unlock(&chip->lock);
+
+       if (ret) {
+               dev_err(&client->dev, "failed loading pattern\n");
+               return ret;
+       }
+
+       return len;
+fail:
+       dev_err(&client->dev, "wrong pattern format\n");
+       return -EINVAL;
+}
+
+static ssize_t store_engine_load(struct device *dev,
+                                    struct device_attribute *attr,
+                                    const char *buf, size_t len, int nr)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       return lp5521_do_store_load(&chip->engines[nr - 1], buf, len);
+}
+
+#define store_load(nr)                                                 \
+static ssize_t store_engine##nr##_load(struct device *dev,             \
+                                    struct device_attribute *attr,     \
+                                    const char *buf, size_t len)       \
+{                                                                      \
+       return store_engine_load(dev, attr, buf, len, nr);              \
+}
+store_load(1)
+store_load(2)
+store_load(3)
+
+static ssize_t show_engine_mode(struct device *dev,
+                               struct device_attribute *attr,
+                               char *buf, int nr)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       switch (chip->engines[nr - 1].mode) {
+       case LP5521_CMD_RUN:
+               return sprintf(buf, "run\n");
+       case LP5521_CMD_LOAD:
+               return sprintf(buf, "load\n");
+       case LP5521_CMD_DISABLED:
+               return sprintf(buf, "disabled\n");
+       default:
+               return sprintf(buf, "disabled\n");
+       }
+}
+
+#define show_mode(nr)                                                  \
+static ssize_t show_engine##nr##_mode(struct device *dev,              \
+                                   struct device_attribute *attr,      \
+                                   char *buf)                          \
+{                                                                      \
+       return show_engine_mode(dev, attr, buf, nr);                    \
+}
+show_mode(1)
+show_mode(2)
+show_mode(3)
+
+static ssize_t store_engine_mode(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf, size_t len, int nr)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       struct lp5521_engine *engine = &chip->engines[nr - 1];
+       mutex_lock(&chip->lock);
+
+       if (!strncmp(buf, "run", 3))
+               lp5521_set_mode(engine, LP5521_CMD_RUN);
+       else if (!strncmp(buf, "load", 4))
+               lp5521_set_mode(engine, LP5521_CMD_LOAD);
+       else if (!strncmp(buf, "disabled", 8))
+               lp5521_set_mode(engine, LP5521_CMD_DISABLED);
+
+       mutex_unlock(&chip->lock);
+       return len;
+}
+
+#define store_mode(nr)                                                 \
+static ssize_t store_engine##nr##_mode(struct device *dev,             \
+                                    struct device_attribute *attr,     \
+                                    const char *buf, size_t len)       \
+{                                                                      \
+       return store_engine_mode(dev, attr, buf, len, nr);              \
+}
+store_mode(1)
+store_mode(2)
+store_mode(3)
+
+static ssize_t show_max_current(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+       struct led_classdev *led_cdev = dev_get_drvdata(dev);
+       struct lp5521_led *led = cdev_to_led(led_cdev);
+
+       return sprintf(buf, "%d\n", led->max_current);
+}
+
+static ssize_t show_current(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+       struct led_classdev *led_cdev = dev_get_drvdata(dev);
+       struct lp5521_led *led = cdev_to_led(led_cdev);
+
+       return sprintf(buf, "%d\n", led->led_current);
+}
+
+static ssize_t store_current(struct device *dev,
+                            struct device_attribute *attr,
+                            const char *buf, size_t len)
+{
+       struct led_classdev *led_cdev = dev_get_drvdata(dev);
+       struct lp5521_led *led = cdev_to_led(led_cdev);
+       struct lp5521_chip *chip = led_to_lp5521(led);
+       ssize_t ret;
+       unsigned long curr;
+
+       if (strict_strtoul(buf, 0, &curr))
+               return -EINVAL;
+
+       if (curr > led->max_current)
+               return -EINVAL;
+
+       mutex_lock(&chip->lock);
+       ret = lp5521_set_led_current(chip, led->id, curr);
+       mutex_unlock(&chip->lock);
+
+       if (ret < 0)
+               return ret;
+
+       led->led_current = (u8)curr;
+
+       return len;
+}
+
+static ssize_t lp5521_selftest(struct device *dev,
+                              struct device_attribute *attr,
+                              char *buf)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       int ret;
+
+       mutex_lock(&chip->lock);
+       ret = lp5521_run_selftest(chip, buf);
+       mutex_unlock(&chip->lock);
+       return sprintf(buf, "%s\n", ret ? "FAIL" : "OK");
+}
+
+/* led class device attributes */
+static DEVICE_ATTR(led_current, S_IRUGO | S_IWUGO, show_current, store_current);
+static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);
+
+static struct attribute *lp5521_led_attributes[] = {
+       &dev_attr_led_current.attr,
+       &dev_attr_max_current.attr,
+       NULL,
+};
+
+static struct attribute_group lp5521_led_attribute_group = {
+       .attrs = lp5521_led_attributes
+};
+
+/* device attributes */
+static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUGO,
+                  show_engine1_mode, store_engine1_mode);
+static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUGO,
+                  show_engine2_mode, store_engine2_mode);
+static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUGO,
+                  show_engine3_mode, store_engine3_mode);
+static DEVICE_ATTR(engine1_load, S_IWUGO, NULL, store_engine1_load);
+static DEVICE_ATTR(engine2_load, S_IWUGO, NULL, store_engine2_load);
+static DEVICE_ATTR(engine3_load, S_IWUGO, NULL, store_engine3_load);
+static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
+
+static struct attribute *lp5521_attributes[] = {
+       &dev_attr_engine1_mode.attr,
+       &dev_attr_engine2_mode.attr,
+       &dev_attr_engine3_mode.attr,
+       &dev_attr_selftest.attr,
+       NULL
+};
+
+static struct attribute *lp5521_engine1_attributes[] = {
+       &dev_attr_engine1_load.attr,
+       NULL
+};
+
+static struct attribute *lp5521_engine2_attributes[] = {
+       &dev_attr_engine2_load.attr,
+       NULL
+};
+
+static struct attribute *lp5521_engine3_attributes[] = {
+       &dev_attr_engine3_load.attr,
+       NULL
+};
+
+static const struct attribute_group lp5521_group = {
+       .attrs = lp5521_attributes,
+};
+
+static const struct attribute_group lp5521_engine_group[] = {
+       {.attrs = lp5521_engine1_attributes },
+       {.attrs = lp5521_engine2_attributes },
+       {.attrs = lp5521_engine3_attributes },
+};
+
+static int lp5521_register_sysfs(struct i2c_client *client)
+{
+       struct device *dev = &client->dev;
+       return sysfs_create_group(&dev->kobj, &lp5521_group);
+}
+
+static void lp5521_unregister_sysfs(struct i2c_client *client)
+{
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       struct device *dev = &client->dev;
+       int i;
+
+       sysfs_remove_group(&dev->kobj, &lp5521_group);
+
+       for (i = 0; i <  ARRAY_SIZE(chip->engines); i++) {
+               if (chip->engines[i].mode == LP5521_CMD_LOAD)
+                       sysfs_remove_group(&dev->kobj,
+                                       chip->engines[i].attributes);
+       }
+
+       for (i = 0; i < chip->num_leds; i++)
+               sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
+                               &lp5521_led_attribute_group);
+}
+
+static int __init lp5521_init_led(struct lp5521_led *led,
+                               struct i2c_client *client,
+                               int chan, struct lp5521_platform_data *pdata)
+{
+       struct device *dev = &client->dev;
+       char name[32];
+       int res;
+
+       if (chan >= LP5521_MAX_LEDS)
+               return -EINVAL;
+
+       if (pdata->led_config[chan].led_current == 0)
+               return 0;
+
+       led->led_current = pdata->led_config[chan].led_current;
+       led->max_current = pdata->led_config[chan].max_current;
+       led->chan_nr = pdata->led_config[chan].chan_nr;
+
+       if (led->chan_nr >= LP5521_MAX_LEDS) {
+               dev_err(dev, "Use channel numbers between 0 and %d\n",
+                       LP5521_MAX_LEDS - 1);
+               return -EINVAL;
+       }
+
+       snprintf(name, sizeof(name), "%s:channel%d", client->name, chan);
+       led->cdev.brightness_set = lp5521_set_brightness;
+       led->cdev.name = name;
+       res = led_classdev_register(dev, &led->cdev);
+       if (res < 0) {
+               dev_err(dev, "couldn't register led on channel %d\n", chan);
+               return res;
+       }
+
+       res = sysfs_create_group(&led->cdev.dev->kobj,
+                       &lp5521_led_attribute_group);
+       if (res < 0) {
+               dev_err(dev, "couldn't register current attribute\n");
+               led_classdev_unregister(&led->cdev);
+               return res;
+       }
+       return 0;
+}
+
+static int lp5521_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       struct lp5521_chip              *chip;
+       struct lp5521_platform_data     *pdata;
+       int ret, i, led;
+
+       chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       i2c_set_clientdata(client, chip);
+       chip->client = client;
+
+       pdata = client->dev.platform_data;
+
+       if (!pdata) {
+               dev_err(&client->dev, "no platform data\n");
+               ret = -EINVAL;
+               goto fail1;
+       }
+
+       mutex_init(&chip->lock);
+
+       chip->pdata   = pdata;
+
+       if (pdata->setup_resources) {
+               ret = pdata->setup_resources();
+               if (ret < 0)
+                       goto fail1;
+       }
+
+       if (pdata->enable) {
+               pdata->enable(0);
+               usleep_range(1000, 10000);
+               pdata->enable(1);
+               usleep_range(1000, 10000); /* Spec says min 500us */
+       }
+
+       ret = lp5521_detect(client);
+
+       if (ret) {
+               dev_err(&client->dev, "Chip not found\n");
+               goto fail2;
+       }
+
+       dev_info(&client->dev, "%s programmable led chip found\n", id->name);
+
+       ret = lp5521_configure(client, lp5521_engine_group);
+       if (ret < 0) {
+               dev_err(&client->dev, "error configuring chip\n");
+               goto fail2;
+       }
+
+       /* Initialize leds */
+       chip->num_channels = pdata->num_channels;
+       chip->num_leds = 0;
+       led = 0;
+       for (i = 0; i < pdata->num_channels; i++) {
+               /* Do not initialize channels that are not connected */
+               if (pdata->led_config[i].led_current == 0)
+                       continue;
+
+               ret = lp5521_init_led(&chip->leds[led], client, i, pdata);
+               if (ret) {
+                       dev_err(&client->dev, "error initializing leds\n");
+                       goto fail3;
+               }
+               chip->num_leds++;
+
+               chip->leds[led].id = led;
+               /* Set initial LED current */
+               lp5521_set_led_current(chip, led,
+                               chip->leds[led].led_current);
+
+               INIT_WORK(&(chip->leds[led].brightness_work),
+                       lp5521_led_brightness_work);
+
+               led++;
+       }
+
+       ret = lp5521_register_sysfs(client);
+       if (ret) {
+               dev_err(&client->dev, "registering sysfs failed\n");
+               goto fail3;
+       }
+       return ret;
+fail3:
+       for (i = 0; i < chip->num_leds; i++) {
+               led_classdev_unregister(&chip->leds[i].cdev);
+               cancel_work_sync(&chip->leds[i].brightness_work);
+       }
+fail2:
+       if (pdata->enable)
+               pdata->enable(0);
+       if (pdata->release_resources)
+               pdata->release_resources();
+fail1:
+       kfree(chip);
+       return ret;
+}
+
+static int lp5521_remove(struct i2c_client *client)
+{
+       struct lp5521_chip *chip = i2c_get_clientdata(client);
+       int i;
+
+       lp5521_unregister_sysfs(client);
+
+       for (i = 0; i < chip->num_leds; i++) {
+               led_classdev_unregister(&chip->leds[i].cdev);
+               cancel_work_sync(&chip->leds[i].brightness_work);
+       }
+
+       if (chip->pdata->enable)
+               chip->pdata->enable(0);
+       if (chip->pdata->release_resources)
+               chip->pdata->release_resources();
+       kfree(chip);
+       return 0;
+}
+
+static const struct i2c_device_id lp5521_id[] = {
+       { "lp5521", 0 }, /* Three channel chip */
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, lp5521_id);
+
+static struct i2c_driver lp5521_driver = {
+       .driver = {
+               .name   = "lp5521",
+       },
+       .probe          = lp5521_probe,
+       .remove         = lp5521_remove,
+       .id_table       = lp5521_id,
+};
+
+static int __init lp5521_init(void)
+{
+       int ret;
+
+       ret = i2c_add_driver(&lp5521_driver);
+
+       if (ret < 0)
+               printk(KERN_ALERT "Adding lp5521 driver failed\n");
+
+       return ret;
+}
+
+static void __exit lp5521_exit(void)
+{
+       i2c_del_driver(&lp5521_driver);
+}
+
+module_init(lp5521_init);
+module_exit(lp5521_exit);
+
+MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
+MODULE_DESCRIPTION("LP5521 LED engine");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/leds-lp5521.h b/include/linux/leds-lp5521.h
new file mode 100644 (file)
index 0000000..38368d7
--- /dev/null
@@ -0,0 +1,47 @@
+/*
+ * LP5521 LED chip driver.
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __LINUX_LP5521_H
+#define __LINUX_LP5521_H
+
+/* See Documentation/leds/leds-lp5521.txt */
+
+struct lp5521_led_config {
+       u8              chan_nr;
+       u8              led_current; /* mA x10, 0 if led is not connected */
+       u8              max_current;
+};
+
+#define LP5521_CLOCK_AUTO      0
+#define LP5521_CLOCK_INT       1
+#define LP5521_CLOCK_EXT       2
+
+struct lp5521_platform_data {
+       struct lp5521_led_config *led_config;
+       u8      num_channels;
+       u8      clock_mode;
+       int     (*setup_resources)(void);
+       void    (*release_resources)(void);
+       void    (*enable)(bool state);
+};
+
+#endif /* __LINUX_LP5521_H */