linux/drivers/mfd/rsmu_i2c.c
Min Li 53d3ff7be4 mfd: rsmu: support I2C SMBus access
8a3400x device implements its own reg_read and reg_write,
which only supports I2C bus access. This patch adds support
for SMBus access.

Signed-off-by: Min Li <min.li.xe@renesas.com>
Link: https://lore.kernel.org/r/LV3P220MB12021342F302AADEB6C1601CA0192@LV3P220MB1202.NAMP220.PROD.OUTLOOK.COM
Signed-off-by: Lee Jones <lee@kernel.org>
2024-05-10 15:39:18 +01:00

380 lines
9.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* I2C driver for Renesas Synchronization Management Unit (SMU) devices.
*
* Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company.
*/
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rsmu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include "rsmu.h"
/*
* 32-bit register address: the lower 8 bits of the register address come
* from the offset addr byte and the upper 24 bits come from the page register.
*/
#define RSMU_CM_PAGE_ADDR 0xFC
#define RSMU_CM_PAGE_MASK 0xFFFFFF00
#define RSMU_CM_ADDRESS_MASK 0x000000FF
/*
* 15-bit register address: the lower 7 bits of the register address come
* from the offset addr byte and the upper 8 bits come from the page register.
*/
#define RSMU_SABRE_PAGE_ADDR 0x7F
#define RSMU_SABRE_PAGE_WINDOW 128
typedef int (*rsmu_rw_device)(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes);
static const struct regmap_range_cfg rsmu_sabre_range_cfg[] = {
{
.range_min = 0,
.range_max = 0x400,
.selector_reg = RSMU_SABRE_PAGE_ADDR,
.selector_mask = 0xFF,
.selector_shift = 0,
.window_start = 0,
.window_len = RSMU_SABRE_PAGE_WINDOW,
}
};
static bool rsmu_sabre_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case RSMU_SABRE_PAGE_ADDR:
return false;
default:
return true;
}
}
static int rsmu_smbus_i2c_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
{
struct i2c_client *client = to_i2c_client(rsmu->dev);
return i2c_smbus_write_i2c_block_data(client, reg, bytes, buf);
}
static int rsmu_smbus_i2c_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
{
struct i2c_client *client = to_i2c_client(rsmu->dev);
int ret;
ret = i2c_smbus_read_i2c_block_data(client, reg, bytes, buf);
if (ret == bytes)
return 0;
else if (ret < 0)
return ret;
else
return -EIO;
}
static int rsmu_i2c_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
{
struct i2c_client *client = to_i2c_client(rsmu->dev);
struct i2c_msg msg[2];
int cnt;
msg[0].addr = client->addr;
msg[0].flags = 0;
msg[0].len = 1;
msg[0].buf = &reg;
msg[1].addr = client->addr;
msg[1].flags = I2C_M_RD;
msg[1].len = bytes;
msg[1].buf = buf;
cnt = i2c_transfer(client->adapter, msg, 2);
if (cnt < 0) {
dev_err(rsmu->dev, "i2c_transfer failed at addr: %04x!", reg);
return cnt;
} else if (cnt != 2) {
dev_err(rsmu->dev,
"i2c_transfer sent only %d of 2 messages", cnt);
return -EIO;
}
return 0;
}
static int rsmu_i2c_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
{
struct i2c_client *client = to_i2c_client(rsmu->dev);
/* we add 1 byte for device register */
u8 msg[RSMU_MAX_WRITE_COUNT + 1];
int cnt;
if (bytes > RSMU_MAX_WRITE_COUNT)
return -EINVAL;
msg[0] = reg;
memcpy(&msg[1], buf, bytes);
cnt = i2c_master_send(client, msg, bytes + 1);
if (cnt < 0) {
dev_err(&client->dev,
"i2c_master_send failed at addr: %04x!", reg);
return cnt;
}
return 0;
}
static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u32 reg,
rsmu_rw_device rsmu_write_device)
{
u32 page = reg & RSMU_CM_PAGE_MASK;
u8 buf[4];
int err;
/* Do not modify offset register for none-scsr registers */
if (reg < RSMU_CM_SCSR_BASE)
return 0;
/* Simply return if we are on the same page */
if (rsmu->page == page)
return 0;
buf[0] = 0x0;
buf[1] = (u8)((page >> 8) & 0xFF);
buf[2] = (u8)((page >> 16) & 0xFF);
buf[3] = (u8)((page >> 24) & 0xFF);
err = rsmu_write_device(rsmu, RSMU_CM_PAGE_ADDR, buf, sizeof(buf));
if (err)
dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page);
else
/* Remember the last page */
rsmu->page = page;
return err;
}
static int rsmu_i2c_reg_read(void *context, unsigned int reg, unsigned int *val)
{
struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
int err;
err = rsmu_write_page_register(rsmu, reg, rsmu_i2c_write_device);
if (err)
return err;
err = rsmu_i2c_read_device(rsmu, addr, (u8 *)val, 1);
if (err)
dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);
return err;
}
static int rsmu_i2c_reg_write(void *context, unsigned int reg, unsigned int val)
{
struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
u8 data = (u8)val;
int err;
err = rsmu_write_page_register(rsmu, reg, rsmu_i2c_write_device);
if (err)
return err;
err = rsmu_i2c_write_device(rsmu, addr, &data, 1);
if (err)
dev_err(rsmu->dev,
"Failed to write offset address 0x%x\n", addr);
return err;
}
static int rsmu_smbus_i2c_reg_read(void *context, unsigned int reg, unsigned int *val)
{
struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
int err;
err = rsmu_write_page_register(rsmu, reg, rsmu_smbus_i2c_write_device);
if (err)
return err;
err = rsmu_smbus_i2c_read_device(rsmu, addr, (u8 *)val, 1);
if (err)
dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);
return err;
}
static int rsmu_smbus_i2c_reg_write(void *context, unsigned int reg, unsigned int val)
{
struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
u8 data = (u8)val;
int err;
err = rsmu_write_page_register(rsmu, reg, rsmu_smbus_i2c_write_device);
if (err)
return err;
err = rsmu_smbus_i2c_write_device(rsmu, addr, &data, 1);
if (err)
dev_err(rsmu->dev,
"Failed to write offset address 0x%x\n", addr);
return err;
}
static const struct regmap_config rsmu_i2c_cm_regmap_config = {
.reg_bits = 32,
.val_bits = 8,
.max_register = 0x20120000,
.reg_read = rsmu_i2c_reg_read,
.reg_write = rsmu_i2c_reg_write,
.cache_type = REGCACHE_NONE,
};
static const struct regmap_config rsmu_smbus_i2c_cm_regmap_config = {
.reg_bits = 32,
.val_bits = 8,
.max_register = 0x20120000,
.reg_read = rsmu_smbus_i2c_reg_read,
.reg_write = rsmu_smbus_i2c_reg_write,
.cache_type = REGCACHE_NONE,
};
static const struct regmap_config rsmu_sabre_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x400,
.ranges = rsmu_sabre_range_cfg,
.num_ranges = ARRAY_SIZE(rsmu_sabre_range_cfg),
.volatile_reg = rsmu_sabre_volatile_reg,
.cache_type = REGCACHE_MAPLE,
.can_multi_write = true,
};
static const struct regmap_config rsmu_sl_regmap_config = {
.reg_bits = 16,
.val_bits = 8,
.reg_format_endian = REGMAP_ENDIAN_BIG,
.max_register = 0x340,
.cache_type = REGCACHE_NONE,
.can_multi_write = true,
};
static int rsmu_i2c_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
const struct regmap_config *cfg;
struct rsmu_ddata *rsmu;
int ret;
rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL);
if (!rsmu)
return -ENOMEM;
i2c_set_clientdata(client, rsmu);
rsmu->dev = &client->dev;
rsmu->type = (enum rsmu_type)id->driver_data;
switch (rsmu->type) {
case RSMU_CM:
if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
cfg = &rsmu_i2c_cm_regmap_config;
} else if (i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_I2C_BLOCK)) {
cfg = &rsmu_smbus_i2c_cm_regmap_config;
} else {
dev_err(rsmu->dev, "Unsupported i2c adapter\n");
return -ENOTSUPP;
}
break;
case RSMU_SABRE:
cfg = &rsmu_sabre_regmap_config;
break;
case RSMU_SL:
cfg = &rsmu_sl_regmap_config;
break;
default:
dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
return -ENODEV;
}
if (rsmu->type == RSMU_CM)
rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg);
else
rsmu->regmap = devm_regmap_init_i2c(client, cfg);
if (IS_ERR(rsmu->regmap)) {
ret = PTR_ERR(rsmu->regmap);
dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);
return ret;
}
return rsmu_core_init(rsmu);
}
static void rsmu_i2c_remove(struct i2c_client *client)
{
struct rsmu_ddata *rsmu = i2c_get_clientdata(client);
rsmu_core_exit(rsmu);
}
static const struct i2c_device_id rsmu_i2c_id[] = {
{ "8a34000", RSMU_CM },
{ "8a34001", RSMU_CM },
{ "82p33810", RSMU_SABRE },
{ "82p33811", RSMU_SABRE },
{ "8v19n850", RSMU_SL },
{ "8v19n851", RSMU_SL },
{}
};
MODULE_DEVICE_TABLE(i2c, rsmu_i2c_id);
static const struct of_device_id rsmu_i2c_of_match[] = {
{ .compatible = "idt,8a34000", .data = (void *)RSMU_CM },
{ .compatible = "idt,8a34001", .data = (void *)RSMU_CM },
{ .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },
{ .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },
{ .compatible = "idt,8v19n850", .data = (void *)RSMU_SL },
{ .compatible = "idt,8v19n851", .data = (void *)RSMU_SL },
{}
};
MODULE_DEVICE_TABLE(of, rsmu_i2c_of_match);
static struct i2c_driver rsmu_i2c_driver = {
.driver = {
.name = "rsmu-i2c",
.of_match_table = rsmu_i2c_of_match,
},
.probe = rsmu_i2c_probe,
.remove = rsmu_i2c_remove,
.id_table = rsmu_i2c_id,
};
static int __init rsmu_i2c_init(void)
{
return i2c_add_driver(&rsmu_i2c_driver);
}
subsys_initcall(rsmu_i2c_init);
static void __exit rsmu_i2c_exit(void)
{
i2c_del_driver(&rsmu_i2c_driver);
}
module_exit(rsmu_i2c_exit);
MODULE_DESCRIPTION("Renesas SMU I2C driver");
MODULE_LICENSE("GPL");