regmap.c

/*
 * Register map access API
 *
 * Copyright 2011 Wolfson Microelectronics plc
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.
 */

#include <linux/device.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/rbtree.h>

#define CREATE_TRACE_POINTS
#include <trace/events/regmap.h>

#include "internal.h"

/*
 * Sometimes for failures during very early init the trace
 * infrastructure isn't available early enough to be used.  For this
 * sort of problem defining LOG_DEVICE will add printks for basic
 * register I/O on a specific device.
 */
#undef LOG_DEVICE

static int _regmap_update_bits(struct regmap *map, unsigned int reg,
			       unsigned int mask, unsigned int val,
			       bool *change);

bool regmap_writeable(struct regmap *map, unsigned int reg)
{
	if (map->max_register && reg > map->max_register)
		return false;

	if (map->writeable_reg)
		return map->writeable_reg(map->dev, reg);

	return true;
}

bool regmap_readable(struct regmap *map, unsigned int reg)
{
	if (map->max_register && reg > map->max_register)
		return false;

	if (map->format.format_write)
		return false;

	if (map->readable_reg)
		return map->readable_reg(map->dev, reg);

	return true;
}

bool regmap_volatile(struct regmap *map, unsigned int reg)
{
	if (!regmap_readable(map, reg))
		return false;

	if (map->volatile_reg)
		return map->volatile_reg(map->dev, reg);

	return true;
}

bool regmap_precious(struct regmap *map, unsigned int reg)
{
	if (!regmap_readable(map, reg))
		return false;

	if (map->precious_reg)
		return map->precious_reg(map->dev, reg);

	return false;
}

static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
	unsigned int num)
{
	unsigned int i;

	for (i = 0; i < num; i++)
		if (!regmap_volatile(map, reg + i))
			return false;

	return true;
}

static void regmap_format_2_6_write(struct regmap *map,
				     unsigned int reg, unsigned int val)
{
	u8 *out = map->work_buf;

	*out = (reg << 6) | val;
}

static void regmap_format_4_12_write(struct regmap *map,
				     unsigned int reg, unsigned int val)
{
	__be16 *out = map->work_buf;
	*out = cpu_to_be16((reg << 12) | val);
}

static void regmap_format_7_9_write(struct regmap *map,
				    unsigned int reg, unsigned int val)
{
	__be16 *out = map->work_buf;
	*out = cpu_to_be16((reg << 9) | val);
}

static void regmap_format_10_14_write(struct regmap *map,
				    unsigned int reg, unsigned int val)
{
	u8 *out = map->work_buf;

	out[2] = val;
	out[1] = (val >> 8) | (reg << 6);
	out[0] = reg >> 2;
}

static void regmap_format_8(void *buf, unsigned int val, unsigned int shift)
{
	u8 *b = buf;

	b[0] = val << shift;
}

static void regmap_format_16_be(void *buf, unsigned int val, unsigned int shift)
{
	__be16 *b = buf;

	b[0] = cpu_to_be16(val << shift);
}

static void regmap_format_16_native(void *buf, unsigned int val,
				    unsigned int shift)
{
	*(u16 *)buf = val << shift;
}

static void regmap_format_24(void *buf, unsigned int val, unsigned int shift)
{
	u8 *b = buf;

	val <<= shift;

	b[0] = val >> 16;
	b[1] = val >> 8;
	b[2] = val;
}

static void regmap_format_32_be(void *buf, unsigned int val, unsigned int shift)
{
	__be32 *b = buf;

	b[0] = cpu_to_be32(val << shift);
}

static void regmap_format_32_native(void *buf, unsigned int val,
				    unsigned int shift)
{
	*(u32 *)buf = val << shift;
}

static unsigned int regmap_parse_8(void *buf)
{
	u8 *b = buf;

	return b[0];
}

static unsigned int regmap_parse_16_be(void *buf)
{
	__be16 *b = buf;

	b[0] = be16_to_cpu(b[0]);

	return b[0];
}

static unsigned int regmap_parse_16_native(void *buf)
{
	return *(u16 *)buf;
}

static unsigned int regmap_parse_24(void *buf)
{
	u8 *b = buf;
	unsigned int ret = b[2];
	ret |= ((unsigned int)b[1]) << 8;
	ret |= ((unsigned int)b[0]) << 16;

	return ret;