text: /*
   * 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 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];
  	ssize_t 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 = simple_open,
  	.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_one(aat2870->en_pin, GPIOF_OUT_INIT_HIGH,
  				       "aat2870-en");
  		if (ret < 0) {
  			dev_err(&client->dev,
  				"Failed to request GPIO %d\n", aat2870->en_pin);
  			goto out_kfree;
  		}
  	}
  
  	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_SLEEP
  static int aat2870_i2c_suspend(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct aat2870_data *aat2870 = i2c_get_clientdata(client);
  
  	aat2870_disable(aat2870);
  
  	return 0;
  }
  
  static int aat2870_i2c_resume(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	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;
  }
  #endif /* CONFIG_PM_SLEEP */
  
  static SIMPLE_DEV_PM_OPS(aat2870_pm_ops, aat2870_i2c_suspend,
  			 aat2870_i2c_resume);
  
  static const 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,
  		.pm	= &aat2870_pm_ops,
  	},
  	.probe		= aat2870_i2c_probe,
  	.remove		= aat2870_i2c_remove,
  	.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>");
  