mfd: Add AAT2870 mfd driver
authorJin Park <jinyoungp@nvidia.com>
Mon, 4 Jul 2011 17:48:12 +0000 (19:48 +0200)
committerSamuel Ortiz <sameo@linux.intel.com>
Sun, 31 Jul 2011 21:28:26 +0000 (23:28 +0200)
Add mfd core driver for AnalogicTech AAT2870.
The AAT2870 is communication through I2C and contains backlight and
regulator components.

Signed-off-by: Jin Park <jinyoungp@nvidia.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
drivers/mfd/Kconfig
drivers/mfd/Makefile
drivers/mfd/aat2870-core.c [new file with mode: 0644]
include/linux/mfd/aat2870.h [new file with mode: 0644]

index c261364..21574bd 100644 (file)
@@ -760,6 +760,16 @@ config MFD_PM8XXX_IRQ
 config TPS65911_COMPARATOR
        tristate
 
+config MFD_AAT2870_CORE
+       bool "Support for the AnalogicTech AAT2870"
+       select MFD_CORE
+       depends on I2C=y && GPIOLIB
+       help
+         If you say yes here you get support for the AAT2870.
+         This driver provides common support for accessing the device,
+         additional drivers must be enabled in order to use the
+         functionality of the device.
+
 endif # MFD_SUPPORT
 
 menu "Multimedia Capabilities Port drivers"
index ca1867d..c580203 100644 (file)
@@ -101,3 +101,4 @@ obj-$(CONFIG_MFD_OMAP_USB_HOST)     += omap-usb-host.o
 obj-$(CONFIG_MFD_PM8921_CORE)  += pm8921-core.o
 obj-$(CONFIG_MFD_PM8XXX_IRQ)   += pm8xxx-irq.o
 obj-$(CONFIG_TPS65911_COMPARATOR)      += tps65911-comparator.o
+obj-$(CONFIG_MFD_AAT2870_CORE) += aat2870-core.o
diff --git a/drivers/mfd/aat2870-core.c b/drivers/mfd/aat2870-core.c
new file mode 100644 (file)
index 0000000..345dc65
--- /dev/null
@@ -0,0 +1,535 @@
+/*
+ * linux/drivers/mfd/aat2870-core.c
+ *
+ * Copyright (c) 2011, NVIDIA Corporation.
+ * Author: Jin Park <jinyoungp@nvidia.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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/aat2870.h>
+#include <linux/regulator/machine.h>
+
+static struct aat2870_register aat2870_regs[AAT2870_REG_NUM] = {
+       /* readable, writeable, value */
+       { 0, 1, 0x00 }, /* 0x00 AAT2870_BL_CH_EN */
+       { 0, 1, 0x16 }, /* 0x01 AAT2870_BLM */
+       { 0, 1, 0x16 }, /* 0x02 AAT2870_BLS */
+       { 0, 1, 0x56 }, /* 0x03 AAT2870_BL1 */
+       { 0, 1, 0x56 }, /* 0x04 AAT2870_BL2 */
+       { 0, 1, 0x56 }, /* 0x05 AAT2870_BL3 */
+       { 0, 1, 0x56 }, /* 0x06 AAT2870_BL4 */
+       { 0, 1, 0x56 }, /* 0x07 AAT2870_BL5 */
+       { 0, 1, 0x56 }, /* 0x08 AAT2870_BL6 */
+       { 0, 1, 0x56 }, /* 0x09 AAT2870_BL7 */
+       { 0, 1, 0x56 }, /* 0x0A AAT2870_BL8 */
+       { 0, 1, 0x00 }, /* 0x0B AAT2870_FLR */
+       { 0, 1, 0x03 }, /* 0x0C AAT2870_FM */
+       { 0, 1, 0x03 }, /* 0x0D AAT2870_FS */
+       { 0, 1, 0x10 }, /* 0x0E AAT2870_ALS_CFG0 */
+       { 0, 1, 0x06 }, /* 0x0F AAT2870_ALS_CFG1 */
+       { 0, 1, 0x00 }, /* 0x10 AAT2870_ALS_CFG2 */
+       { 1, 0, 0x00 }, /* 0x11 AAT2870_AMB */
+       { 0, 1, 0x00 }, /* 0x12 AAT2870_ALS0 */
+       { 0, 1, 0x00 }, /* 0x13 AAT2870_ALS1 */
+       { 0, 1, 0x00 }, /* 0x14 AAT2870_ALS2 */
+       { 0, 1, 0x00 }, /* 0x15 AAT2870_ALS3 */
+       { 0, 1, 0x00 }, /* 0x16 AAT2870_ALS4 */
+       { 0, 1, 0x00 }, /* 0x17 AAT2870_ALS5 */
+       { 0, 1, 0x00 }, /* 0x18 AAT2870_ALS6 */
+       { 0, 1, 0x00 }, /* 0x19 AAT2870_ALS7 */
+       { 0, 1, 0x00 }, /* 0x1A AAT2870_ALS8 */
+       { 0, 1, 0x00 }, /* 0x1B AAT2870_ALS9 */
+       { 0, 1, 0x00 }, /* 0x1C AAT2870_ALSA */
+       { 0, 1, 0x00 }, /* 0x1D AAT2870_ALSB */
+       { 0, 1, 0x00 }, /* 0x1E AAT2870_ALSC */
+       { 0, 1, 0x00 }, /* 0x1F AAT2870_ALSD */
+       { 0, 1, 0x00 }, /* 0x20 AAT2870_ALSE */
+       { 0, 1, 0x00 }, /* 0x21 AAT2870_ALSF */
+       { 0, 1, 0x00 }, /* 0x22 AAT2870_SUB_SET */
+       { 0, 1, 0x00 }, /* 0x23 AAT2870_SUB_CTRL */
+       { 0, 1, 0x00 }, /* 0x24 AAT2870_LDO_AB */
+       { 0, 1, 0x00 }, /* 0x25 AAT2870_LDO_CD */
+       { 0, 1, 0x00 }, /* 0x26 AAT2870_LDO_EN */
+};
+
+static struct mfd_cell aat2870_devs[] = {
+       {
+               .name = "aat2870-backlight",
+               .id = AAT2870_ID_BL,
+               .pdata_size = sizeof(struct aat2870_bl_platform_data),
+       },
+       {
+               .name = "aat2870-regulator",
+               .id = AAT2870_ID_LDOA,
+               .pdata_size = sizeof(struct regulator_init_data),
+       },
+       {
+               .name = "aat2870-regulator",
+               .id = AAT2870_ID_LDOB,
+               .pdata_size = sizeof(struct regulator_init_data),
+       },
+       {
+               .name = "aat2870-regulator",
+               .id = AAT2870_ID_LDOC,
+               .pdata_size = sizeof(struct regulator_init_data),
+       },
+       {
+               .name = "aat2870-regulator",
+               .id = AAT2870_ID_LDOD,
+               .pdata_size = sizeof(struct regulator_init_data),
+       },
+};
+
+static int __aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
+{
+       int ret;
+
+       if (addr >= AAT2870_REG_NUM) {
+               dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
+               return -EINVAL;
+       }
+
+       if (!aat2870->reg_cache[addr].readable) {
+               *val = aat2870->reg_cache[addr].value;
+               goto out;
+       }
+
+       ret = i2c_master_send(aat2870->client, &addr, 1);
+       if (ret < 0)
+               return ret;
+       if (ret != 1)
+               return -EIO;
+
+       ret = i2c_master_recv(aat2870->client, val, 1);
+       if (ret < 0)
+               return ret;
+       if (ret != 1)
+               return -EIO;
+
+out:
+       dev_dbg(aat2870->dev, "read: addr=0x%02x, val=0x%02x\n", addr, *val);
+       return 0;
+}
+
+static int __aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
+{
+       u8 msg[2];
+       int ret;
+
+       if (addr >= AAT2870_REG_NUM) {
+               dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
+               return -EINVAL;
+       }
+
+       if (!aat2870->reg_cache[addr].writeable) {
+               dev_err(aat2870->dev, "Address 0x%02x is not writeable\n",
+                       addr);
+               return -EINVAL;
+       }
+
+       msg[0] = addr;
+       msg[1] = val;
+       ret = i2c_master_send(aat2870->client, msg, 2);
+       if (ret < 0)
+               return ret;
+       if (ret != 2)
+               return -EIO;
+
+       aat2870->reg_cache[addr].value = val;
+
+       dev_dbg(aat2870->dev, "write: addr=0x%02x, val=0x%02x\n", addr, val);
+       return 0;
+}
+
+static int aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
+{
+       int ret;
+
+       mutex_lock(&aat2870->io_lock);
+       ret = __aat2870_read(aat2870, addr, val);
+       mutex_unlock(&aat2870->io_lock);
+
+       return ret;
+}
+
+static int aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
+{
+       int ret;
+
+       mutex_lock(&aat2870->io_lock);
+       ret = __aat2870_write(aat2870, addr, val);
+       mutex_unlock(&aat2870->io_lock);
+
+       return ret;
+}
+
+static int aat2870_update(struct aat2870_data *aat2870, u8 addr, u8 mask,
+                         u8 val)
+{
+       int change;
+       u8 old_val, new_val;
+       int ret;
+
+       mutex_lock(&aat2870->io_lock);
+
+       ret = __aat2870_read(aat2870, addr, &old_val);
+       if (ret)
+               goto out_unlock;
+
+       new_val = (old_val & ~mask) | (val & mask);
+       change = old_val != new_val;
+       if (change)
+               ret = __aat2870_write(aat2870, addr, new_val);
+
+out_unlock:
+       mutex_unlock(&aat2870->io_lock);
+
+       return ret;
+}
+
+static inline void aat2870_enable(struct aat2870_data *aat2870)
+{
+       if (aat2870->en_pin >= 0)
+               gpio_set_value(aat2870->en_pin, 1);
+
+       aat2870->is_enable = 1;
+}
+
+static inline void aat2870_disable(struct aat2870_data *aat2870)
+{
+       if (aat2870->en_pin >= 0)
+               gpio_set_value(aat2870->en_pin, 0);
+
+       aat2870->is_enable = 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static ssize_t aat2870_dump_reg(struct aat2870_data *aat2870, char *buf)
+{
+       u8 addr, val;
+       ssize_t count = 0;
+       int ret;
+
+       count += sprintf(buf, "aat2870 registers\n");
+       for (addr = 0; addr < AAT2870_REG_NUM; addr++) {
+               count += sprintf(buf + count, "0x%02x: ", addr);
+               if (count >= PAGE_SIZE - 1)
+                       break;
+
+               ret = aat2870->read(aat2870, addr, &val);
+               if (ret == 0)
+                       count += snprintf(buf + count, PAGE_SIZE - count,
+                                         "0x%02x", val);
+               else
+                       count += snprintf(buf + count, PAGE_SIZE - count,
+                                         "<read fail: %d>", ret);
+
+               if (count >= PAGE_SIZE - 1)
+                       break;
+
+               count += snprintf(buf + count, PAGE_SIZE - count, "\n");
+               if (count >= PAGE_SIZE - 1)
+                       break;
+       }
+
+       /* Truncate count; min() would cause a warning */
+       if (count >= PAGE_SIZE)
+               count = PAGE_SIZE - 1;
+
+       return count;
+}
+
+static int aat2870_reg_open_file(struct inode *inode, struct file *file)
+{
+       file->private_data = inode->i_private;
+
+       return 0;
+}
+
+static ssize_t aat2870_reg_read_file(struct file *file, char __user *user_buf,
+                                    size_t count, loff_t *ppos)
+{
+       struct aat2870_data *aat2870 = file->private_data;
+       char *buf;
+       ssize_t ret;
+
+       buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       ret = aat2870_dump_reg(aat2870, buf);
+       if (ret >= 0)
+               ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+
+       kfree(buf);
+
+       return ret;
+}
+
+static ssize_t aat2870_reg_write_file(struct file *file,
+                                     const char __user *user_buf, size_t count,
+                                     loff_t *ppos)
+{
+       struct aat2870_data *aat2870 = file->private_data;
+       char buf[32];
+       int buf_size;
+       char *start = buf;
+       unsigned long addr, val;
+       int ret;
+
+       buf_size = min(count, (sizeof(buf)-1));
+       if (copy_from_user(buf, user_buf, buf_size)) {
+               dev_err(aat2870->dev, "Failed to copy from user\n");
+               return -EFAULT;
+       }
+       buf[buf_size] = 0;
+
+       while (*start == ' ')
+               start++;
+
+       addr = simple_strtoul(start, &start, 16);
+       if (addr >= AAT2870_REG_NUM) {
+               dev_err(aat2870->dev, "Invalid address, 0x%lx\n", addr);
+               return -EINVAL;
+       }
+
+       while (*start == ' ')
+               start++;
+
+       if (strict_strtoul(start, 16, &val))
+               return -EINVAL;
+
+       ret = aat2870->write(aat2870, (u8)addr, (u8)val);
+       if (ret)
+               return ret;
+
+       return buf_size;
+}
+
+static const struct file_operations aat2870_reg_fops = {
+       .open = aat2870_reg_open_file,
+       .read = aat2870_reg_read_file,
+       .write = aat2870_reg_write_file,
+};
+
+static void aat2870_init_debugfs(struct aat2870_data *aat2870)
+{
+       aat2870->dentry_root = debugfs_create_dir("aat2870", NULL);
+       if (!aat2870->dentry_root) {
+               dev_warn(aat2870->dev,
+                        "Failed to create debugfs root directory\n");
+               return;
+       }
+
+       aat2870->dentry_reg = debugfs_create_file("regs", 0644,
+                                                 aat2870->dentry_root,
+                                                 aat2870, &aat2870_reg_fops);
+       if (!aat2870->dentry_reg)
+               dev_warn(aat2870->dev,
+                        "Failed to create debugfs register file\n");
+}
+
+static void aat2870_uninit_debugfs(struct aat2870_data *aat2870)
+{
+       debugfs_remove_recursive(aat2870->dentry_root);
+}
+#else
+static inline void aat2870_init_debugfs(struct aat2870_data *aat2870)
+{
+}
+
+static inline void aat2870_uninit_debugfs(struct aat2870_data *aat2870)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static int aat2870_i2c_probe(struct i2c_client *client,
+                            const struct i2c_device_id *id)
+{
+       struct aat2870_platform_data *pdata = client->dev.platform_data;
+       struct aat2870_data *aat2870;
+       int i, j;
+       int ret = 0;
+
+       aat2870 = kzalloc(sizeof(struct aat2870_data), GFP_KERNEL);
+       if (!aat2870) {
+               dev_err(&client->dev,
+                       "Failed to allocate memory for aat2870\n");
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       aat2870->dev = &client->dev;
+       dev_set_drvdata(aat2870->dev, aat2870);
+
+       aat2870->client = client;
+       i2c_set_clientdata(client, aat2870);
+
+       aat2870->reg_cache = aat2870_regs;
+
+       if (pdata->en_pin < 0)
+               aat2870->en_pin = -1;
+       else
+               aat2870->en_pin = pdata->en_pin;
+
+       aat2870->init = pdata->init;
+       aat2870->uninit = pdata->uninit;
+       aat2870->read = aat2870_read;
+       aat2870->write = aat2870_write;
+       aat2870->update = aat2870_update;
+
+       mutex_init(&aat2870->io_lock);
+
+       if (aat2870->init)
+               aat2870->init(aat2870);
+
+       if (aat2870->en_pin >= 0) {
+               ret = gpio_request(aat2870->en_pin, "aat2870-en");
+               if (ret < 0) {
+                       dev_err(&client->dev,
+                               "Failed to request GPIO %d\n", aat2870->en_pin);
+                       goto out_kfree;
+               }
+               gpio_direction_output(aat2870->en_pin, 1);
+       }
+
+       aat2870_enable(aat2870);
+
+       for (i = 0; i < pdata->num_subdevs; i++) {
+               for (j = 0; j < ARRAY_SIZE(aat2870_devs); j++) {
+                       if ((pdata->subdevs[i].id == aat2870_devs[j].id) &&
+                                       !strcmp(pdata->subdevs[i].name,
+                                               aat2870_devs[j].name)) {
+                               aat2870_devs[j].platform_data =
+                                       pdata->subdevs[i].platform_data;
+                               break;
+                       }
+               }
+       }
+
+       ret = mfd_add_devices(aat2870->dev, 0, aat2870_devs,
+                             ARRAY_SIZE(aat2870_devs), NULL, 0);
+       if (ret != 0) {
+               dev_err(aat2870->dev, "Failed to add subdev: %d\n", ret);
+               goto out_disable;
+       }
+
+       aat2870_init_debugfs(aat2870);
+
+       return 0;
+
+out_disable:
+       aat2870_disable(aat2870);
+       if (aat2870->en_pin >= 0)
+               gpio_free(aat2870->en_pin);
+out_kfree:
+       kfree(aat2870);
+out:
+       return ret;
+}
+
+static int aat2870_i2c_remove(struct i2c_client *client)
+{
+       struct aat2870_data *aat2870 = i2c_get_clientdata(client);
+
+       aat2870_uninit_debugfs(aat2870);
+
+       mfd_remove_devices(aat2870->dev);
+       aat2870_disable(aat2870);
+       if (aat2870->en_pin >= 0)
+               gpio_free(aat2870->en_pin);
+       if (aat2870->uninit)
+               aat2870->uninit(aat2870);
+       kfree(aat2870);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM
+static int aat2870_i2c_suspend(struct i2c_client *client, pm_message_t state)
+{
+       struct aat2870_data *aat2870 = i2c_get_clientdata(client);
+
+       aat2870_disable(aat2870);
+
+       return 0;
+}
+
+static int aat2870_i2c_resume(struct i2c_client *client)
+{
+       struct aat2870_data *aat2870 = i2c_get_clientdata(client);
+       struct aat2870_register *reg = NULL;
+       int i;
+
+       aat2870_enable(aat2870);
+
+       /* restore registers */
+       for (i = 0; i < AAT2870_REG_NUM; i++) {
+               reg = &aat2870->reg_cache[i];
+               if (reg->writeable)
+                       aat2870->write(aat2870, i, reg->value);
+       }
+
+       return 0;
+}
+#else
+#define aat2870_i2c_suspend    NULL
+#define aat2870_i2c_resume     NULL
+#endif /* CONFIG_PM */
+
+static struct i2c_device_id aat2870_i2c_id_table[] = {
+       { "aat2870", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, aat2870_i2c_id_table);
+
+static struct i2c_driver aat2870_i2c_driver = {
+       .driver = {
+               .name   = "aat2870",
+               .owner  = THIS_MODULE,
+       },
+       .probe          = aat2870_i2c_probe,
+       .remove         = aat2870_i2c_remove,
+       .suspend        = aat2870_i2c_suspend,
+       .resume         = aat2870_i2c_resume,
+       .id_table       = aat2870_i2c_id_table,
+};
+
+static int __init aat2870_init(void)
+{
+       return i2c_add_driver(&aat2870_i2c_driver);
+}
+subsys_initcall(aat2870_init);
+
+static void __exit aat2870_exit(void)
+{
+       i2c_del_driver(&aat2870_i2c_driver);
+}
+module_exit(aat2870_exit);
+
+MODULE_DESCRIPTION("Core support for the AnalogicTech AAT2870");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");
diff --git a/include/linux/mfd/aat2870.h b/include/linux/mfd/aat2870.h
new file mode 100644 (file)
index 0000000..89212df
--- /dev/null
@@ -0,0 +1,181 @@
+/*
+ * linux/include/linux/mfd/aat2870.h
+ *
+ * Copyright (c) 2011, NVIDIA Corporation.
+ * Author: Jin Park <jinyoungp@nvidia.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_MFD_AAT2870_H
+#define __LINUX_MFD_AAT2870_H
+
+#include <linux/debugfs.h>
+#include <linux/i2c.h>
+
+/* Register offsets */
+#define AAT2870_BL_CH_EN       0x00
+#define AAT2870_BLM            0x01
+#define AAT2870_BLS            0x02
+#define AAT2870_BL1            0x03
+#define AAT2870_BL2            0x04
+#define AAT2870_BL3            0x05
+#define AAT2870_BL4            0x06
+#define AAT2870_BL5            0x07
+#define AAT2870_BL6            0x08
+#define AAT2870_BL7            0x09
+#define AAT2870_BL8            0x0A
+#define AAT2870_FLR            0x0B
+#define AAT2870_FM             0x0C
+#define AAT2870_FS             0x0D
+#define AAT2870_ALS_CFG0       0x0E
+#define AAT2870_ALS_CFG1       0x0F
+#define AAT2870_ALS_CFG2       0x10
+#define AAT2870_AMB            0x11
+#define AAT2870_ALS0           0x12
+#define AAT2870_ALS1           0x13
+#define AAT2870_ALS2           0x14
+#define AAT2870_ALS3           0x15
+#define AAT2870_ALS4           0x16
+#define AAT2870_ALS5           0x17
+#define AAT2870_ALS6           0x18
+#define AAT2870_ALS7           0x19
+#define AAT2870_ALS8           0x1A
+#define AAT2870_ALS9           0x1B
+#define AAT2870_ALSA           0x1C
+#define AAT2870_ALSB           0x1D
+#define AAT2870_ALSC           0x1E
+#define AAT2870_ALSD           0x1F
+#define AAT2870_ALSE           0x20
+#define AAT2870_ALSF           0x21
+#define AAT2870_SUB_SET                0x22
+#define AAT2870_SUB_CTRL       0x23
+#define AAT2870_LDO_AB         0x24
+#define AAT2870_LDO_CD         0x25
+#define AAT2870_LDO_EN         0x26
+#define AAT2870_REG_NUM                0x27
+
+/* Device IDs */
+enum aat2870_id {
+       AAT2870_ID_BL,
+       AAT2870_ID_LDOA,
+       AAT2870_ID_LDOB,
+       AAT2870_ID_LDOC,
+       AAT2870_ID_LDOD
+};
+
+/* Backlight channels */
+#define AAT2870_BL_CH1         0x01
+#define AAT2870_BL_CH2         0x02
+#define AAT2870_BL_CH3         0x04
+#define AAT2870_BL_CH4         0x08
+#define AAT2870_BL_CH5         0x10
+#define AAT2870_BL_CH6         0x20
+#define AAT2870_BL_CH7         0x40
+#define AAT2870_BL_CH8         0x80
+#define AAT2870_BL_CH_ALL      0xFF
+
+/* Backlight current magnitude (mA) */
+enum aat2870_current {
+       AAT2870_CURRENT_0_45,
+       AAT2870_CURRENT_0_90,
+       AAT2870_CURRENT_1_80,
+       AAT2870_CURRENT_2_70,
+       AAT2870_CURRENT_3_60,
+       AAT2870_CURRENT_4_50,
+       AAT2870_CURRENT_5_40,
+       AAT2870_CURRENT_6_30,
+       AAT2870_CURRENT_7_20,
+       AAT2870_CURRENT_8_10,
+       AAT2870_CURRENT_9_00,
+       AAT2870_CURRENT_9_90,
+       AAT2870_CURRENT_10_8,
+       AAT2870_CURRENT_11_7,
+       AAT2870_CURRENT_12_6,
+       AAT2870_CURRENT_13_5,
+       AAT2870_CURRENT_14_4,
+       AAT2870_CURRENT_15_3,
+       AAT2870_CURRENT_16_2,
+       AAT2870_CURRENT_17_1,
+       AAT2870_CURRENT_18_0,
+       AAT2870_CURRENT_18_9,
+       AAT2870_CURRENT_19_8,
+       AAT2870_CURRENT_20_7,
+       AAT2870_CURRENT_21_6,
+       AAT2870_CURRENT_22_5,
+       AAT2870_CURRENT_23_4,
+       AAT2870_CURRENT_24_3,
+       AAT2870_CURRENT_25_2,
+       AAT2870_CURRENT_26_1,
+       AAT2870_CURRENT_27_0,
+       AAT2870_CURRENT_27_9
+};
+
+struct aat2870_register {
+       bool readable;
+       bool writeable;
+       u8 value;
+};
+
+struct aat2870_data {
+       struct device *dev;
+       struct i2c_client *client;
+
+       struct mutex io_lock;
+       struct aat2870_register *reg_cache; /* register cache */
+       int en_pin; /* enable GPIO pin (if < 0, ignore this value) */
+       bool is_enable;
+
+       /* init and uninit for platform specified */
+       int (*init)(struct aat2870_data *aat2870);
+       void (*uninit)(struct aat2870_data *aat2870);
+
+       /* i2c io funcntions */
+       int (*read)(struct aat2870_data *aat2870, u8 addr, u8 *val);
+       int (*write)(struct aat2870_data *aat2870, u8 addr, u8 val);
+       int (*update)(struct aat2870_data *aat2870, u8 addr, u8 mask, u8 val);
+
+       /* for debugfs */
+       struct dentry *dentry_root;
+       struct dentry *dentry_reg;
+};
+
+struct aat2870_subdev_info {
+       int id;
+       const char *name;
+       void *platform_data;
+};
+
+struct aat2870_platform_data {
+       int en_pin; /* enable GPIO pin (if < 0, ignore this value) */
+
+       struct aat2870_subdev_info *subdevs;
+       int num_subdevs;
+
+       /* init and uninit for platform specified */
+       int (*init)(struct aat2870_data *aat2870);
+       void (*uninit)(struct aat2870_data *aat2870);
+};
+
+struct aat2870_bl_platform_data {
+       /* backlight channels, default is AAT2870_BL_CH_ALL */
+       int channels;
+       /* backlight current magnitude, default is AAT2870_CURRENT_27_9 */
+       int max_current;
+       /* maximum brightness, default is 255 */
+       int max_brightness;
+};
+
+#endif /* __LINUX_MFD_AAT2870_H */