linux/drivers/base/regmap/regmap-sdw.c
Srinivas Kandagatla 95856d1f3c
regmap: sdw: check for invalid multi-register writes config
SoundWire code as it is only supports Bulk register writes and
it does not support multi-register writes.

Any drivers that set can_multi_write and use regmap_multi_reg_write() will
easily endup with programming the hardware incorrectly without any errors.

So, add this check in bus code to be able to validate the drivers config.

Fixes: 522272047d ("regmap: sdw: Remove 8-bit value size restriction")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230523154747.5429-1-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-05-24 11:21:51 +01:00

103 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright(c) 2015-17 Intel Corporation.
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/soundwire/sdw.h>
#include <linux/types.h>
#include "internal.h"
static int regmap_sdw_write(void *context, const void *val_buf, size_t val_size)
{
struct device *dev = context;
struct sdw_slave *slave = dev_to_sdw_dev(dev);
/* First word of buffer contains the destination address */
u32 addr = le32_to_cpu(*(const __le32 *)val_buf);
const u8 *val = val_buf;
return sdw_nwrite_no_pm(slave, addr, val_size - sizeof(addr), val + sizeof(addr));
}
static int regmap_sdw_gather_write(void *context,
const void *reg_buf, size_t reg_size,
const void *val_buf, size_t val_size)
{
struct device *dev = context;
struct sdw_slave *slave = dev_to_sdw_dev(dev);
u32 addr = le32_to_cpu(*(const __le32 *)reg_buf);
return sdw_nwrite_no_pm(slave, addr, val_size, val_buf);
}
static int regmap_sdw_read(void *context,
const void *reg_buf, size_t reg_size,
void *val_buf, size_t val_size)
{
struct device *dev = context;
struct sdw_slave *slave = dev_to_sdw_dev(dev);
u32 addr = le32_to_cpu(*(const __le32 *)reg_buf);
return sdw_nread_no_pm(slave, addr, val_size, val_buf);
}
static const struct regmap_bus regmap_sdw = {
.write = regmap_sdw_write,
.gather_write = regmap_sdw_gather_write,
.read = regmap_sdw_read,
.reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
.val_format_endian_default = REGMAP_ENDIAN_LITTLE,
};
static int regmap_sdw_config_check(const struct regmap_config *config)
{
/* Register addresses are 32 bits wide */
if (config->reg_bits != 32)
return -ENOTSUPP;
if (config->pad_bits != 0)
return -ENOTSUPP;
/* Only bulk writes are supported not multi-register writes */
if (config->can_multi_write)
return -ENOTSUPP;
return 0;
}
struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name)
{
int ret;
ret = regmap_sdw_config_check(config);
if (ret)
return ERR_PTR(ret);
return __regmap_init(&sdw->dev, &regmap_sdw,
&sdw->dev, config, lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__regmap_init_sdw);
struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name)
{
int ret;
ret = regmap_sdw_config_check(config);
if (ret)
return ERR_PTR(ret);
return __devm_regmap_init(&sdw->dev, &regmap_sdw,
&sdw->dev, config, lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw);
MODULE_DESCRIPTION("Regmap SoundWire Module");
MODULE_LICENSE("GPL v2");