// SPDX-License-Identifier: GPL-2.0-only

  /*
   * linux/drivers/mfd/aat2870-core.c
   *
   * Copyright (c) 2011, NVIDIA Corporation.
   * Author: Jin Park <jinyoungp@nvidia.com>

   */
  
  #include <linux/kernel.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
  ", 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
  ", 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
  ", addr);
  		return -EINVAL;
  	}
  
  	if (!aat2870->reg_cache[addr].writeable) {
  		dev_err(aat2870->dev, "Address 0x%02x is not writeable
  ",
  			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
  ", 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
  ");
  	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, "
  ");
  		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, (size_t)(sizeof(buf)-1));

  	if (copy_from_user(buf, user_buf, buf_size)) {
  		dev_err(aat2870->dev, "Failed to copy from user
  ");
  		return -EFAULT;
  	}
  	buf[buf_size] = 0;
  
  	while (*start == ' ')
  		start++;

  	ret = kstrtoul(start, 16, &addr);
  	if (ret)
  		return ret;

  	if (addr >= AAT2870_REG_NUM) {
  		dev_err(aat2870->dev, "Invalid address, 0x%lx
  ", addr);
  		return -EINVAL;
  	}
  
  	while (*start == ' ')
  		start++;

  	ret = kstrtoul(start, 16, &val);
  	if (ret)
  		return ret;

  
  	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);

  	debugfs_create_file("regs", 0644, aat2870->dentry_root, aat2870,
  			    &aat2870_reg_fops);

  }

  #else
  static inline void aat2870_init_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 = dev_get_platdata(&client->dev);

  	struct aat2870_data *aat2870;
  	int i, j;
  	int ret = 0;

  	aat2870 = devm_kzalloc(&client->dev, sizeof(struct aat2870_data),
  				GFP_KERNEL);

  	if (!aat2870)

  		return -ENOMEM;

  
  	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 = devm_gpio_request_one(&client->dev, aat2870->en_pin,
  					GPIOF_OUT_INIT_HIGH, "aat2870-en");

  		if (ret < 0) {
  			dev_err(&client->dev,
  				"Failed to request GPIO %d
  ", aat2870->en_pin);

  			return ret;

  		}

  	}
  
  	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, NULL);

  	if (ret != 0) {
  		dev_err(aat2870->dev, "Failed to add subdev: %d
  ", ret);
  		goto out_disable;
  	}
  
  	aat2870_init_debugfs(aat2870);
  
  	return 0;
  
  out_disable:
  	aat2870_disable(aat2870);

  	return ret;
  }

  #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 },
  	{ }
  };

  
  static struct i2c_driver aat2870_i2c_driver = {
  	.driver = {

  		.name			= "aat2870",
  		.pm			= &aat2870_pm_ops,
  		.suppress_bind_attrs	= true,

  	},
  	.probe		= aat2870_i2c_probe,

  	.id_table	= aat2870_i2c_id_table,
  };
  
  static int __init aat2870_init(void)
  {
  	return i2c_add_driver(&aat2870_i2c_driver);
  }
  subsys_initcall(aat2870_init);