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>
#include <linux/sched.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);

static int _regmap_bus_read(void *context, unsigned int reg,
			    unsigned int *val);
static int _regmap_bus_formatted_write(void *context, unsigned int reg,
				       unsigned int val);
static int _regmap_bus_raw_write(void *context, unsigned int reg,
				 unsigned int val);

bool regmap_reg_in_ranges(unsigned int reg,
			  const struct regmap_range *ranges,
			  unsigned int nranges)
{
	const struct regmap_range *r;
	int i;

	for (i = 0, r = ranges; i < nranges; i++, r++)
		if (regmap_reg_in_range(reg, r))
			return true;
	return false;
}
EXPORT_SYMBOL_GPL(regmap_reg_in_ranges);

bool regmap_check_range_table(struct regmap *map, unsigned int reg,
			      const struct regmap_access_table *table)
{
	/* Check "no ranges" first */
	if (regmap_reg_in_ranges(reg, table->no_ranges, table->n_no_ranges))
		return false;

	/* In case zero "yes ranges" are supplied, any reg is OK */
	if (!table->n_yes_ranges)
		return true;

	return regmap_reg_in_ranges(reg, table->yes_ranges,
				    table->n_yes_ranges);
}
EXPORT_SYMBOL_GPL(regmap_check_range_table);

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);

	if (map->wr_table)
		return regmap_check_range_table(map, reg, map->wr_table);

	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);

	if (map->rd_table)
		return regmap_check_range_table(map, reg, map->rd_table);

	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);

	if (map->volatile_table)
		return regmap_check_range_table(map, reg, map->volatile_table);

	if (map->cache_ops)
		return false;
	else
		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);

	if (map->precious_table)
		return regmap_check_range_table(map, reg, map->precious_table);

	return false;
}

static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
	size_t 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;
}