text: // SPDX-License-Identifier: GPL-2.0
  //
  // Register map access API - SPMI support
  //
  // Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
  //
  // Based on regmap-i2c.c:
  // Copyright 2011 Wolfson Microelectronics plc
  // Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  
  #include <linux/regmap.h>
  #include <linux/spmi.h>
  #include <linux/module.h>
  #include <linux/init.h>
  
  static int regmap_spmi_base_read(void *context,
  				 const void *reg, size_t reg_size,
  				 void *val, size_t val_size)
  {
  	u8 addr = *(u8 *)reg;
  	int err = 0;
  
  	BUG_ON(reg_size != 1);
  
  	while (val_size-- && !err)
  		err = spmi_register_read(context, addr++, val++);
  
  	return err;
  }
  
  static int regmap_spmi_base_gather_write(void *context,
  					 const void *reg, size_t reg_size,
  					 const void *val, size_t val_size)
  {
  	const u8 *data = val;
  	u8 addr = *(u8 *)reg;
  	int err = 0;
  
  	BUG_ON(reg_size != 1);
  
  	/*
  	 * SPMI defines a more bandwidth-efficient 'Register 0 Write' sequence,
  	 * use it when possible.
  	 */
  	if (addr == 0 && val_size) {
  		err = spmi_register_zero_write(context, *data);
  		if (err)
  			goto err_out;
  
  		data++;
  		addr++;
  		val_size--;
  	}
  
  	while (val_size) {
  		err = spmi_register_write(context, addr, *data);
  		if (err)
  			goto err_out;
  
  		data++;
  		addr++;
  		val_size--;
  	}
  
  err_out:
  	return err;
  }
  
  static int regmap_spmi_base_write(void *context, const void *data,
  				  size_t count)
  {
  	BUG_ON(count < 1);
  	return regmap_spmi_base_gather_write(context, data, 1, data + 1,
  					     count - 1);
  }
  
  static const struct regmap_bus regmap_spmi_base = {
  	.read				= regmap_spmi_base_read,
  	.write				= regmap_spmi_base_write,
  	.gather_write			= regmap_spmi_base_gather_write,
  	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
  	.val_format_endian_default	= REGMAP_ENDIAN_NATIVE,
  };
  
  struct regmap *__regmap_init_spmi_base(struct spmi_device *sdev,
  				       const struct regmap_config *config,
  				       struct lock_class_key *lock_key,
  				       const char *lock_name)
  {
  	return __regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
  			     lock_key, lock_name);
  }
  EXPORT_SYMBOL_GPL(__regmap_init_spmi_base);
  
  struct regmap *__devm_regmap_init_spmi_base(struct spmi_device *sdev,
  					    const struct regmap_config *config,
  					    struct lock_class_key *lock_key,
  					    const char *lock_name)
  {
  	return __devm_regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
  				  lock_key, lock_name);
  }
  EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_base);
  
  static int regmap_spmi_ext_read(void *context,
  				const void *reg, size_t reg_size,
  				void *val, size_t val_size)
  {
  	int err = 0;
  	size_t len;
  	u16 addr;
  
  	BUG_ON(reg_size != 2);
  
  	addr = *(u16 *)reg;
  
  	/*
  	 * Split accesses into two to take advantage of the more
  	 * bandwidth-efficient 'Extended Register Read' command when possible
  	 */
  	while (addr <= 0xFF && val_size) {
  		len = min_t(size_t, val_size, 16);
  
  		err = spmi_ext_register_read(context, addr, val, len);
  		if (err)
  			goto err_out;
  
  		addr += len;
  		val += len;
  		val_size -= len;
  	}
  
  	while (val_size) {
  		len = min_t(size_t, val_size, 8);
  
  		err = spmi_ext_register_readl(context, addr, val, len);
  		if (err)
  			goto err_out;
  
  		addr += len;
  		val += len;
  		val_size -= len;
  	}
  
  err_out:
  	return err;
  }
  
  static int regmap_spmi_ext_gather_write(void *context,
  					const void *reg, size_t reg_size,
  					const void *val, size_t val_size)
  {
  	int err = 0;
  	size_t len;
  	u16 addr;
  
  	BUG_ON(reg_size != 2);
  
  	addr = *(u16 *)reg;
  
  	while (addr <= 0xFF && val_size) {
  		len = min_t(size_t, val_size, 16);
  
  		err = spmi_ext_register_write(context, addr, val, len);
  		if (err)
  			goto err_out;
  
  		addr += len;
  		val += len;
  		val_size -= len;
  	}
  
  	while (val_size) {
  		len = min_t(size_t, val_size, 8);
  
  		err = spmi_ext_register_writel(context, addr, val, len);
  		if (err)
  			goto err_out;
  
  		addr += len;
  		val += len;
  		val_size -= len;
  	}
  
  err_out:
  	return err;
  }
  
  static int regmap_spmi_ext_write(void *context, const void *data,
  				 size_t count)
  {
  	BUG_ON(count < 2);
  	return regmap_spmi_ext_gather_write(context, data, 2, data + 2,
  					    count - 2);
  }
  
  static const struct regmap_bus regmap_spmi_ext = {
  	.read				= regmap_spmi_ext_read,
  	.write				= regmap_spmi_ext_write,
  	.gather_write			= regmap_spmi_ext_gather_write,
  	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
  	.val_format_endian_default	= REGMAP_ENDIAN_NATIVE,
  };
  
  struct regmap *__regmap_init_spmi_ext(struct spmi_device *sdev,
  				      const struct regmap_config *config,
  				      struct lock_class_key *lock_key,
  				      const char *lock_name)
  {
  	return __regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
  			     lock_key, lock_name);
  }
  EXPORT_SYMBOL_GPL(__regmap_init_spmi_ext);
  
  struct regmap *__devm_regmap_init_spmi_ext(struct spmi_device *sdev,
  					   const struct regmap_config *config,
  					   struct lock_class_key *lock_key,
  					   const char *lock_name)
  {
  	return __devm_regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
  				  lock_key, lock_name);
  }
  EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_ext);
  
  MODULE_LICENSE("GPL");
  