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

  /*

   * Copyright (C) 2007-2010 ST-Ericsson

   * Low-level core for exclusive access to the AB3100 IC on the I2C bus
   * and some basic chip-configuration.
   * Author: Linus Walleij <linus.walleij@stericsson.com>
   */
  
  #include <linux/i2c.h>
  #include <linux/mutex.h>
  #include <linux/list.h>
  #include <linux/notifier.h>

  #include <linux/slab.h>

  #include <linux/err.h>

  #include <linux/init.h>

  #include <linux/platform_device.h>
  #include <linux/device.h>
  #include <linux/interrupt.h>

  #include <linux/random.h>

  #include <linux/debugfs.h>
  #include <linux/seq_file.h>
  #include <linux/uaccess.h>

  #include <linux/mfd/core.h>

  #include <linux/mfd/ab3100.h>

  #include <linux/mfd/abx500.h>

  
  /* These are the only registers inside AB3100 used in this main file */
  
  /* Interrupt event registers */
  #define AB3100_EVENTA1		0x21
  #define AB3100_EVENTA2		0x22
  #define AB3100_EVENTA3		0x23
  
  /* AB3100 DAC converter registers */
  #define AB3100_DIS		0x00
  #define AB3100_D0C		0x01
  #define AB3100_D1C		0x02
  #define AB3100_D2C		0x03
  #define AB3100_D3C		0x04
  
  /* Chip ID register */
  #define AB3100_CID		0x20
  
  /* AB3100 interrupt registers */
  #define AB3100_IMRA1		0x24
  #define AB3100_IMRA2		0x25
  #define AB3100_IMRA3		0x26
  #define AB3100_IMRB1		0x2B
  #define AB3100_IMRB2		0x2C
  #define AB3100_IMRB3		0x2D
  
  /* System Power Monitoring and control registers */
  #define AB3100_MCA		0x2E
  #define AB3100_MCB		0x2F
  
  /* SIM power up */
  #define AB3100_SUP		0x50
  
  /*
   * I2C communication
   *
   * The AB3100 is usually assigned address 0x48 (7-bit)
   * The chip is defined in the platform i2c_board_data section.
   */

  static int ab3100_get_chip_id(struct device *dev)

  {

  	struct ab3100 *ab3100 = dev_get_drvdata(dev->parent);
  
  	return (int)ab3100->chip_id;

  }

  static int ab3100_set_register_interruptible(struct ab3100 *ab3100,
  	u8 reg, u8 regval)

  {
  	u8 regandval[2] = {reg, regval};
  	int err;
  
  	err = mutex_lock_interruptible(&ab3100->access_mutex);
  	if (err)
  		return err;
  
  	/*
  	 * A two-byte write message with the first byte containing the register
  	 * number and the second byte containing the value to be written
  	 * effectively sets a register in the AB3100.
  	 */
  	err = i2c_master_send(ab3100->i2c_client, regandval, 2);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (write register): %d
  ",
  			err);
  	} else if (err != 2) {
  		dev_err(ab3100->dev,

  			"write error (write register)
  "
  			"  %d bytes transferred (expected 2)
  ",

  			err);
  		err = -EIO;
  	} else {
  		/* All is well */
  		err = 0;
  	}
  	mutex_unlock(&ab3100->access_mutex);

  	return err;

  }

  static int set_register_interruptible(struct device *dev,
  	u8 bank, u8 reg, u8 value)
  {
  	struct ab3100 *ab3100 = dev_get_drvdata(dev->parent);
  
  	return ab3100_set_register_interruptible(ab3100, reg, value);
  }

  
  /*
   * The test registers exist at an I2C bus address up one
   * from the ordinary base. They are not supposed to be used
   * in production code, but sometimes you have to do that
   * anyway. It's currently only used from this file so declare
   * it static and do not export.
   */

  static int ab3100_set_test_register_interruptible(struct ab3100 *ab3100,

  				    u8 reg, u8 regval)
  {
  	u8 regandval[2] = {reg, regval};
  	int err;
  
  	err = mutex_lock_interruptible(&ab3100->access_mutex);
  	if (err)
  		return err;
  
  	err = i2c_master_send(ab3100->testreg_client, regandval, 2);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (write test register): %d
  ",
  			err);
  	} else if (err != 2) {
  		dev_err(ab3100->dev,

  			"write error (write test register)
  "
  			"  %d bytes transferred (expected 2)
  ",

  			err);
  		err = -EIO;
  	} else {
  		/* All is well */
  		err = 0;
  	}
  	mutex_unlock(&ab3100->access_mutex);
  
  	return err;
  }

  static int ab3100_get_register_interruptible(struct ab3100 *ab3100,

  					     u8 reg, u8 *regval)

  {
  	int err;
  
  	err = mutex_lock_interruptible(&ab3100->access_mutex);
  	if (err)
  		return err;
  
  	/*
  	 * AB3100 require an I2C "stop" command between each message, else
  	 * it will not work. The only way of achieveing this with the
  	 * message transport layer is to send the read and write messages
  	 * separately.
  	 */
  	err = i2c_master_send(ab3100->i2c_client, &reg, 1);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (send register address): %d
  ",
  			err);
  		goto get_reg_out_unlock;
  	} else if (err != 1) {
  		dev_err(ab3100->dev,

  			"write error (send register address)
  "
  			"  %d bytes transferred (expected 1)
  ",

  			err);
  		err = -EIO;
  		goto get_reg_out_unlock;
  	} else {
  		/* All is well */
  		err = 0;
  	}
  
  	err = i2c_master_recv(ab3100->i2c_client, regval, 1);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (read register): %d
  ",
  			err);
  		goto get_reg_out_unlock;
  	} else if (err != 1) {
  		dev_err(ab3100->dev,

  			"write error (read register)
  "
  			"  %d bytes transferred (expected 1)
  ",

  			err);
  		err = -EIO;
  		goto get_reg_out_unlock;
  	} else {
  		/* All is well */
  		err = 0;
  	}
  
   get_reg_out_unlock:
  	mutex_unlock(&ab3100->access_mutex);
  	return err;
  }

  static int get_register_interruptible(struct device *dev, u8 bank, u8 reg,

  				      u8 *value)

  {
  	struct ab3100 *ab3100 = dev_get_drvdata(dev->parent);
  
  	return ab3100_get_register_interruptible(ab3100, reg, value);
  }

  static int ab3100_get_register_page_interruptible(struct ab3100 *ab3100,

  			     u8 first_reg, u8 *regvals, u8 numregs)
  {
  	int err;
  
  	if (ab3100->chip_id == 0xa0 ||
  	    ab3100->chip_id == 0xa1)
  		/* These don't support paged reads */
  		return -EIO;
  
  	err = mutex_lock_interruptible(&ab3100->access_mutex);
  	if (err)
  		return err;
  
  	/*
  	 * Paged read also require an I2C "stop" command.
  	 */
  	err = i2c_master_send(ab3100->i2c_client, &first_reg, 1);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (send first register address): %d
  ",
  			err);
  		goto get_reg_page_out_unlock;
  	} else if (err != 1) {
  		dev_err(ab3100->dev,

  			"write error (send first register address)
  "
  			"  %d bytes transferred (expected 1)
  ",

  			err);
  		err = -EIO;
  		goto get_reg_page_out_unlock;
  	}
  
  	err = i2c_master_recv(ab3100->i2c_client, regvals, numregs);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (read register page): %d
  ",
  			err);
  		goto get_reg_page_out_unlock;
  	} else if (err != numregs) {
  		dev_err(ab3100->dev,

  			"write error (read register page)
  "
  			"  %d bytes transferred (expected %d)
  ",

  			err, numregs);
  		err = -EIO;
  		goto get_reg_page_out_unlock;
  	}
  
  	/* All is well */
  	err = 0;
  
   get_reg_page_out_unlock:
  	mutex_unlock(&ab3100->access_mutex);
  	return err;
  }

  static int get_register_page_interruptible(struct device *dev, u8 bank,
  	u8 first_reg, u8 *regvals, u8 numregs)
  {
  	struct ab3100 *ab3100 = dev_get_drvdata(dev->parent);
  
  	return ab3100_get_register_page_interruptible(ab3100,
  			first_reg, regvals, numregs);
  }

  static int ab3100_mask_and_set_register_interruptible(struct ab3100 *ab3100,

  				 u8 reg, u8 andmask, u8 ormask)
  {
  	u8 regandval[2] = {reg, 0};
  	int err;
  
  	err = mutex_lock_interruptible(&ab3100->access_mutex);
  	if (err)
  		return err;
  
  	/* First read out the target register */
  	err = i2c_master_send(ab3100->i2c_client, &reg, 1);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (maskset send address): %d
  ",
  			err);
  		goto get_maskset_unlock;
  	} else if (err != 1) {
  		dev_err(ab3100->dev,

  			"write error (maskset send address)
  "
  			"  %d bytes transferred (expected 1)
  ",

  			err);
  		err = -EIO;
  		goto get_maskset_unlock;
  	}
  
  	err = i2c_master_recv(ab3100->i2c_client, &regandval[1], 1);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (maskset read register): %d
  ",
  			err);
  		goto get_maskset_unlock;
  	} else if (err != 1) {
  		dev_err(ab3100->dev,

  			"write error (maskset read register)
  "
  			"  %d bytes transferred (expected 1)
  ",

  			err);
  		err = -EIO;
  		goto get_maskset_unlock;
  	}
  
  	/* Modify the register */
  	regandval[1] &= andmask;
  	regandval[1] |= ormask;
  
  	/* Write the register */
  	err = i2c_master_send(ab3100->i2c_client, regandval, 2);
  	if (err < 0) {
  		dev_err(ab3100->dev,
  			"write error (write register): %d
  ",
  			err);
  		goto get_maskset_unlock;
  	} else if (err != 2) {
  		dev_err(ab3100->dev,

  			"write error (write register)
  "
  			"  %d bytes transferred (expected 2)
  ",

  			err);
  		err = -EIO;
  		goto get_maskset_unlock;
  	}
  
  	/* All is well */
  	err = 0;
  
   get_maskset_unlock:
  	mutex_unlock(&ab3100->access_mutex);
  	return err;
  }

  static int mask_and_set_register_interruptible(struct device *dev, u8 bank,
  	u8 reg, u8 bitmask, u8 bitvalues)
  {
  	struct ab3100 *ab3100 = dev_get_drvdata(dev->parent);
  
  	return ab3100_mask_and_set_register_interruptible(ab3100,
  			reg, bitmask, (bitmask & bitvalues));
  }

  
  /*
   * Register a simple callback for handling any AB3100 events.
   */
  int ab3100_event_register(struct ab3100 *ab3100,
  			  struct notifier_block *nb)
  {
  	return blocking_notifier_chain_register(&ab3100->event_subscribers,
  					       nb);
  }
  EXPORT_SYMBOL(ab3100_event_register);
  
  /*
   * Remove a previously registered callback.
   */
  int ab3100_event_unregister(struct ab3100 *ab3100,
  			    struct notifier_block *nb)
  {

  	return blocking_notifier_chain_unregister(&ab3100->event_subscribers,

  					    nb);
  }
  EXPORT_SYMBOL(ab3100_event_unregister);

  static int ab3100_event_registers_startup_state_get(struct device *dev,
  					     u8 *event)

  {

  	struct ab3100 *ab3100 = dev_get_drvdata(dev->parent);

  	if (!ab3100->startup_events_read)
  		return -EAGAIN; /* Try again later */

  	memcpy(event, ab3100->startup_events, 3);

  	return 0;
  }

  
  static struct abx500_ops ab3100_ops = {
  	.get_chip_id = ab3100_get_chip_id,
  	.set_register = set_register_interruptible,
  	.get_register = get_register_interruptible,
  	.get_register_page = get_register_page_interruptible,
  	.set_register_page = NULL,
  	.mask_and_set_register = mask_and_set_register_interruptible,
  	.event_registers_startup_state_get =
  		ab3100_event_registers_startup_state_get,
  	.startup_irq_enabled = NULL,
  };

  /*
   * This is a threaded interrupt handler so we can make some
   * I2C calls etc.
   */
  static irqreturn_t ab3100_irq_handler(int irq, void *data)

  {

  	struct ab3100 *ab3100 = data;

  	u8 event_regs[3];
  	u32 fatevent;
  	int err;

  	err = ab3100_get_register_page_interruptible(ab3100, AB3100_EVENTA1,

  				       event_regs, 3);
  	if (err)

  		goto err_event;

  
  	fatevent = (event_regs[0] << 16) |
  		(event_regs[1] << 8) |
  		event_regs[2];
  
  	if (!ab3100->startup_events_read) {

  		ab3100->startup_events[0] = event_regs[0];
  		ab3100->startup_events[1] = event_regs[1];
  		ab3100->startup_events[2] = event_regs[2];

  		ab3100->startup_events_read = true;
  	}
  	/*
  	 * The notified parties will have to mask out the events
  	 * they're interested in and react to them. They will be
  	 * notified on all events, then they use the fatevent value
  	 * to determine if they're interested.
  	 */
  	blocking_notifier_call_chain(&ab3100->event_subscribers,
  				     fatevent, NULL);
  
  	dev_dbg(ab3100->dev,
  		"IRQ Event: 0x%08x
  ", fatevent);

  	return IRQ_HANDLED;

   err_event:

  	dev_dbg(ab3100->dev,

  		"error reading event status
  ");

  	return IRQ_HANDLED;
  }
  
  #ifdef CONFIG_DEBUG_FS
  /*
   * Some debugfs entries only exposed if we're using debug
   */
  static int ab3100_registers_print(struct seq_file *s, void *p)
  {
  	struct ab3100 *ab3100 = s->private;
  	u8 value;
  	u8 reg;

  	seq_puts(s, "AB3100 registers:
  ");

  
  	for (reg = 0; reg < 0xff; reg++) {

  		ab3100_get_register_interruptible(ab3100, reg, &value);

  		seq_printf(s, "[0x%x]:  0x%x
  ", reg, value);
  	}
  	return 0;
  }
  
  static int ab3100_registers_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, ab3100_registers_print, inode->i_private);
  }
  
  static const struct file_operations ab3100_registers_fops = {
  	.open = ab3100_registers_open,
  	.read = seq_read,
  	.llseek = seq_lseek,
  	.release = single_release,
  	.owner = THIS_MODULE,
  };
  
  struct ab3100_get_set_reg_priv {
  	struct ab3100 *ab3100;
  	bool mode;
  };

  static ssize_t ab3100_get_set_reg(struct file *file,
  				  const char __user *user_buf,
  				  size_t count, loff_t *ppos)

  {
  	struct ab3100_get_set_reg_priv *priv = file->private_data;
  	struct ab3100 *ab3100 = priv->ab3100;
  	char buf[32];

  	ssize_t buf_size;

  	int regp;

  	u8 user_reg;

  	int err;
  	int i = 0;
  
  	/* Get userspace string and assure termination */

  	buf_size = min((ssize_t)count, (ssize_t)(sizeof(buf)-1));

  	if (copy_from_user(buf, user_buf, buf_size))
  		return -EFAULT;
  	buf[buf_size] = 0;
  
  	/*
  	 * The idea is here to parse a string which is either
  	 * "0xnn" for reading a register, or "0xaa 0xbb" for
  	 * writing 0xbb to the register 0xaa. First move past
  	 * whitespace and then begin to parse the register.
  	 */
  	while ((i < buf_size) && (buf[i] == ' '))
  		i++;
  	regp = i;
  
  	/*
  	 * Advance pointer to end of string then terminate
  	 * the register string. This is needed to satisfy

  	 * the kstrtou8() function.

  	 */
  	while ((i < buf_size) && (buf[i] != ' '))
  		i++;
  	buf[i] = '\0';

  	err = kstrtou8(&buf[regp], 16, &user_reg);

  	if (err)
  		return err;

  
  	/* Either we read or we write a register here */
  	if (!priv->mode) {
  		/* Reading */

  		u8 regvalue;

  		ab3100_get_register_interruptible(ab3100, user_reg, &regvalue);

  
  		dev_info(ab3100->dev,
  			 "debug read AB3100 reg[0x%02x]: 0x%02x
  ",

  			 user_reg, regvalue);

  	} else {
  		int valp;

  		u8 user_value;

  		u8 regvalue;
  
  		/*
  		 * Writing, we need some value to write to
  		 * the register so keep parsing the string
  		 * from userspace.
  		 */
  		i++;
  		while ((i < buf_size) && (buf[i] == ' '))
  			i++;
  		valp = i;
  		while ((i < buf_size) && (buf[i] != ' '))
  			i++;
  		buf[i] = '\0';

  		err = kstrtou8(&buf[valp], 16, &user_value);

  		if (err)
  			return err;

  		ab3100_set_register_interruptible(ab3100, user_reg, user_value);
  		ab3100_get_register_interruptible(ab3100, user_reg, &regvalue);

  
  		dev_info(ab3100->dev,

  			 "debug write reg[0x%02x]
  "
  			 "  with 0x%02x, after readback: 0x%02x
  ",

  			 user_reg, user_value, regvalue);

  	}
  	return buf_size;
  }
  
  static const struct file_operations ab3100_get_set_reg_fops = {

  	.open = simple_open,

  	.write = ab3100_get_set_reg,

  	.llseek = noop_llseek,

  };

  static struct ab3100_get_set_reg_priv ab3100_get_priv;

  static struct ab3100_get_set_reg_priv ab3100_set_priv;

  
  static void ab3100_setup_debugfs(struct ab3100 *ab3100)
  {

  	struct dentry *ab3100_dir;

  
  	ab3100_dir = debugfs_create_dir("ab3100", NULL);

  
  	debugfs_create_file("registers", S_IRUGO, ab3100_dir, ab3100,
  			    &ab3100_registers_fops);

  
  	ab3100_get_priv.ab3100 = ab3100;
  	ab3100_get_priv.mode = false;

  	debugfs_create_file("get_reg", S_IWUSR, ab3100_dir, &ab3100_get_priv,
  			    &ab3100_get_set_reg_fops);

  
  	ab3100_set_priv.ab3100 = ab3100;
  	ab3100_set_priv.mode = true;

  	debugfs_create_file("set_reg", S_IWUSR, ab3100_dir, &ab3100_set_priv,
  			    &ab3100_get_set_reg_fops);

  }

  #else
  static inline void ab3100_setup_debugfs(struct ab3100 *ab3100)
  {
  }

  #endif
  
  /*
   * Basic set-up, datastructure creation/destruction and I2C interface.
   * This sets up a default config in the AB3100 chip so that it
   * will work as expected.
   */
  
  struct ab3100_init_setting {
  	u8 abreg;
  	u8 setting;
  };

  static const struct ab3100_init_setting ab3100_init_settings[] = {

  	{
  		.abreg = AB3100_MCA,
  		.setting = 0x01
  	}, {
  		.abreg = AB3100_MCB,
  		.setting = 0x30
  	}, {
  		.abreg = AB3100_IMRA1,
  		.setting = 0x00
  	}, {
  		.abreg = AB3100_IMRA2,
  		.setting = 0xFF
  	}, {
  		.abreg = AB3100_IMRA3,
  		.setting = 0x01
  	}, {
  		.abreg = AB3100_IMRB1,

  		.setting = 0xBF

  	}, {
  		.abreg = AB3100_IMRB2,
  		.setting = 0xFF
  	}, {
  		.abreg = AB3100_IMRB3,
  		.setting = 0xFF
  	}, {
  		.abreg = AB3100_SUP,
  		.setting = 0x00
  	}, {
  		.abreg = AB3100_DIS,
  		.setting = 0xF0
  	}, {
  		.abreg = AB3100_D0C,
  		.setting = 0x00
  	}, {
  		.abreg = AB3100_D1C,
  		.setting = 0x00
  	}, {
  		.abreg = AB3100_D2C,
  		.setting = 0x00
  	}, {
  		.abreg = AB3100_D3C,
  		.setting = 0x00
  	},
  };

  static int ab3100_setup(struct ab3100 *ab3100)

  {
  	int err = 0;
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(ab3100_init_settings); i++) {

  		err = ab3100_set_register_interruptible(ab3100,

  					  ab3100_init_settings[i].abreg,
  					  ab3100_init_settings[i].setting);
  		if (err)
  			goto exit_no_setup;
  	}
  
  	/*
  	 * Special trick to make the AB3100 use the 32kHz clock (RTC)

  	 * bit 3 in test register 0x02 is a special, undocumented test

  	 * register bit that only exist in AB3100 P1E
  	 */
  	if (ab3100->chip_id == 0xc4) {
  		dev_warn(ab3100->dev,

  			 "AB3100 P1E variant detected forcing chip to 32KHz
  ");

  		err = ab3100_set_test_register_interruptible(ab3100,
  			0x02, 0x08);

  	}
  
   exit_no_setup:
  	return err;
  }

  /* The subdevices of the AB3100 */
  static struct mfd_cell ab3100_devs[] = {
  	{
  		.name = "ab3100-dac",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-leds",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-power",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-regulators",

  		.of_compatible = "stericsson,ab3100-regulators",

  		.id = -1,
  	},
  	{
  		.name = "ab3100-sim",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-uart",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-rtc",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-charger",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-boost",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-adc",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-fuelgauge",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-vibrator",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-otp",
  		.id = -1,
  	},
  	{
  		.name = "ab3100-codec",
  		.id = -1,
  	},

  };
  
  struct ab_family_id {
  	u8	id;
  	char	*name;
  };

  static const struct ab_family_id ids[] = {

  	/* AB3100 */
  	{
  		.id = 0xc0,
  		.name = "P1A"
  	}, {
  		.id = 0xc1,
  		.name = "P1B"
  	}, {
  		.id = 0xc2,
  		.name = "P1C"
  	}, {
  		.id = 0xc3,
  		.name = "P1D"
  	}, {
  		.id = 0xc4,
  		.name = "P1E"
  	}, {
  		.id = 0xc5,
  		.name = "P1F/R1A"
  	}, {
  		.id = 0xc6,
  		.name = "P1G/R1A"
  	}, {
  		.id = 0xc7,
  		.name = "P2A/R2A"
  	}, {
  		.id = 0xc8,
  		.name = "P2B/R2B"
  	},
  	/* AB3000 variants, not supported */
  	{
  		.id = 0xa0
  	}, {
  		.id = 0xa1
  	}, {
  		.id = 0xa2
  	}, {
  		.id = 0xa3
  	}, {
  		.id = 0xa4
  	}, {
  		.id = 0xa5
  	}, {
  		.id = 0xa6
  	}, {
  		.id = 0xa7
  	},
  	/* Terminator */
  	{
  		.id = 0x00,
  	},
  };

  static int ab3100_probe(struct i2c_client *client,

  				  const struct i2c_device_id *id)

  {
  	struct ab3100 *ab3100;

  	struct ab3100_platform_data *ab3100_plf_data =

  		dev_get_platdata(&client->dev);

  	int err;
  	int i;

  	ab3100 = devm_kzalloc(&client->dev, sizeof(struct ab3100), GFP_KERNEL);

  	if (!ab3100)

  		return -ENOMEM;

  
  	/* Initialize data structure */
  	mutex_init(&ab3100->access_mutex);
  	BLOCKING_INIT_NOTIFIER_HEAD(&ab3100->event_subscribers);
  
  	ab3100->i2c_client = client;
  	ab3100->dev = &ab3100->i2c_client->dev;
  
  	i2c_set_clientdata(client, ab3100);
  
  	/* Read chip ID register */

  	err = ab3100_get_register_interruptible(ab3100, AB3100_CID,
  						&ab3100->chip_id);

  	if (err) {
  		dev_err(&client->dev,

  			"failed to communicate with AB3100 chip
  ");

  		goto exit_no_detect;
  	}
  
  	for (i = 0; ids[i].id != 0x0; i++) {
  		if (ids[i].id == ab3100->chip_id) {

  			if (ids[i].name)

  				break;

  
  			dev_err(&client->dev, "AB3000 is not supported
  ");
  			goto exit_no_detect;

  		}
  	}

  	snprintf(&ab3100->chip_name[0],
  		 sizeof(ab3100->chip_name) - 1, "AB3100 %s", ids[i].name);

  	if (ids[i].id == 0x0) {
  		dev_err(&client->dev, "unknown analog baseband chip id: 0x%x
  ",
  			ab3100->chip_id);

  		dev_err(&client->dev,
  			"accepting it anyway. Please update the driver.
  ");

  		goto exit_no_detect;
  	}
  
  	dev_info(&client->dev, "Detected chip: %s
  ",
  		 &ab3100->chip_name[0]);
  
  	/* Attach a second dummy i2c_client to the test register address */

  	ab3100->testreg_client = i2c_new_dummy_device(client->adapter,

  					       client->addr + 1);

  	if (IS_ERR(ab3100->testreg_client)) {
  		err = PTR_ERR(ab3100->testreg_client);

  		goto exit_no_testreg_client;
  	}

  	err = ab3100_setup(ab3100);
  	if (err)
  		goto exit_no_setup;

  	err = devm_request_threaded_irq(&client->dev,
  					client->irq, NULL, ab3100_irq_handler,
  					IRQF_ONESHOT, "ab3100-core", ab3100);

  	if (err)
  		goto exit_no_irq;

  	err = abx500_register_ops(&client->dev, &ab3100_ops);
  	if (err)
  		goto exit_no_ops;

  	/* Set up and register the platform devices. */

  	for (i = 0; i < ARRAY_SIZE(ab3100_devs); i++) {
  		ab3100_devs[i].platform_data = ab3100_plf_data;
  		ab3100_devs[i].pdata_size = sizeof(struct ab3100_platform_data);
  	}

  	err = mfd_add_devices(&client->dev, 0, ab3100_devs,

  			      ARRAY_SIZE(ab3100_devs), NULL, 0, NULL);

  
  	ab3100_setup_debugfs(ab3100);
  
  	return 0;

   exit_no_ops:

   exit_no_irq:
   exit_no_setup:
  	i2c_unregister_device(ab3100->testreg_client);
   exit_no_testreg_client:
   exit_no_detect:

  	return err;
  }

  static const struct i2c_device_id ab3100_id[] = {

  	{ "ab3100", 0 },

  	{ }
  };

  
  static struct i2c_driver ab3100_driver = {
  	.driver = {

  		.name			= "ab3100",
  		.suppress_bind_attrs	= true,

  	},
  	.id_table	= ab3100_id,
  	.probe		= ab3100_probe,

  };
  
  static int __init ab3100_i2c_init(void)
  {
  	return i2c_add_driver(&ab3100_driver);
  }

  subsys_initcall(ab3100_i2c_init);