linux/drivers/base/regmap/regmap-raw-ram.c
Mark Brown 65dd2f6718
regmap: Provide a ram backed regmap with raw support
Provide a simple, 16 bit only, RAM backed regmap which supports raw I/O for
use in testing.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230610-regcache-raw-kunit-v1-1-583112cd28ac@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-06-12 14:47:54 +01:00

134 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
//
// Register map access API - Memory region with raw access
//
// This is intended for testing only
//
// Copyright (c) 2023, Arm Ltd
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/swab.h>
#include "internal.h"
static unsigned int decode_reg(enum regmap_endian endian, const void *reg)
{
const u16 *r = reg;
if (endian == REGMAP_ENDIAN_BIG)
return be16_to_cpu(*r);
else
return le16_to_cpu(*r);
}
static int regmap_raw_ram_gather_write(void *context,
const void *reg, size_t reg_len,
const void *val, size_t val_len)
{
struct regmap_ram_data *data = context;
unsigned int r;
u16 *our_buf = (u16 *)data->vals;
int i;
if (reg_len != 2)
return -EINVAL;
if (val_len % 2)
return -EINVAL;
r = decode_reg(data->reg_endian, reg);
memcpy(&our_buf[r], val, val_len);
for (i = 0; i < val_len / 2; i++)
data->written[r + i] = true;
return 0;
}
static int regmap_raw_ram_write(void *context, const void *data, size_t count)
{
return regmap_raw_ram_gather_write(context, data, 2,
data + 2, count - 2);
}
static int regmap_raw_ram_read(void *context,
const void *reg, size_t reg_len,
void *val, size_t val_len)
{
struct regmap_ram_data *data = context;
unsigned int r;
u16 *our_buf = (u16 *)data->vals;
int i;
if (reg_len != 2)
return -EINVAL;
if (val_len % 2)
return -EINVAL;
r = decode_reg(data->reg_endian, reg);
memcpy(val, &our_buf[r], val_len);
for (i = 0; i < val_len / 2; i++)
data->read[r + i] = true;
return 0;
}
static void regmap_raw_ram_free_context(void *context)
{
struct regmap_ram_data *data = context;
kfree(data->vals);
kfree(data->read);
kfree(data->written);
kfree(data);
}
static const struct regmap_bus regmap_raw_ram = {
.fast_io = true,
.write = regmap_raw_ram_write,
.gather_write = regmap_raw_ram_gather_write,
.read = regmap_raw_ram_read,
.free_context = regmap_raw_ram_free_context,
};
struct regmap *__regmap_init_raw_ram(const struct regmap_config *config,
struct regmap_ram_data *data,
struct lock_class_key *lock_key,
const char *lock_name)
{
struct regmap *map;
if (config->reg_bits != 16)
return ERR_PTR(-EINVAL);
if (!config->max_register) {
pr_crit("No max_register specified for RAM regmap\n");
return ERR_PTR(-EINVAL);
}
data->read = kcalloc(sizeof(bool), config->max_register + 1,
GFP_KERNEL);
if (!data->read)
return ERR_PTR(-ENOMEM);
data->written = kcalloc(sizeof(bool), config->max_register + 1,
GFP_KERNEL);
if (!data->written)
return ERR_PTR(-ENOMEM);
data->reg_endian = config->reg_format_endian;
map = __regmap_init(NULL, &regmap_raw_ram, data, config,
lock_key, lock_name);
return map;
}
EXPORT_SYMBOL_GPL(__regmap_init_raw_ram);
MODULE_LICENSE("GPL v2");