// SPDX-License-Identifier: GPL-2.0+
/*
* SPI driver for Renesas Synchronization Management Unit (SMU) devices.
*
* Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company.
*/
#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 <linux/spi/spi.h>
#include "rsmu.h"
#define RSMU_CM_PAGE_ADDR 0x7C
#define RSMU_SABRE_PAGE_ADDR 0x7F
#define RSMU_PAGE_MASK 0xFFFFFF80
#define RSMU_ADDR_MASK 0x7F
static int rsmu_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
{
struct spi_device *client = to_spi_device(rsmu->dev);
struct spi_transfer xfer = {0};
struct spi_message msg;
u8 cmd[RSMU_MAX_READ_COUNT + 1] = {0};
u8 rsp[RSMU_MAX_READ_COUNT + 1] = {0};
int ret;
if (bytes > RSMU_MAX_READ_COUNT)
return -EINVAL;
cmd[0] = reg | 0x80;
xfer.rx_buf = rsp;
xfer.len = bytes + 1;
xfer.tx_buf = cmd;
xfer.bits_per_word = client->bits_per_word;
xfer.speed_hz = client->max_speed_hz;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
/*
* 4-wire SPI is a shift register, so for every byte you send,
* you get one back at the same time. Example read from 0xC024,
* which has value of 0x2D
*
* MOSI:
* 7C 00 C0 #Set page register
* A4 00 #MSB is set, so this is read command
* MISO:
* XX 2D #XX is a dummy byte from sending A4 and we
* need to throw it away
*/
ret = spi_sync(client, &msg);
if (ret >= 0)
memcpy(buf, &rsp[1], xfer.len-1);
return ret;
}
static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
{
struct spi_device *client = to_spi_device(rsmu->dev);
struct spi_transfer xfer = {0};
struct spi_message msg;
u8 cmd[RSMU_MAX_WRITE_COUNT + 1] = {0};
if (bytes > RSMU_MAX_WRITE_COUNT)
return -EINVAL;
cmd[0] = reg;
memcpy(&cmd[1], buf, bytes);
xfer.len = bytes + 1;
xfer.tx_buf = cmd;
xfer.bits_per_word = client->bits_per_word;
xfer.speed_hz = client->max_speed_hz;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
return spi_sync(client, &msg);
}
/*
* 1-byte (1B) offset addressing:
* 16-bit register address: the lower 7 bits of the register address come
* from the offset addr byte and the upper 9 bits come from the page register.
*/
static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u32 reg)
{
u8 page_reg;
u8 buf[4];
u16 bytes;
u32 page;
int err;
switch (rsmu->type) {
case RSMU_CM:
/* Do not modify page register for none-scsr registers */
if (reg < RSMU_CM_SCSR_BASE)
return 0;
page_reg = RSMU_CM_PAGE_ADDR;
page = reg & RSMU_PAGE_MASK;
buf[0] = (u8)(page & 0xFF);
buf[1] = (u8)((page >> 8) & 0xFF);
buf[2] = (u8)((page >> 16) & 0xFF);
buf[3] = (u8)((page >> 24) & 0xFF);
bytes = 4;
break;
case RSMU_SABRE:
/* Do not modify page register if reg is page register itself */
if ((reg & RSMU_ADDR_MASK) == RSMU_ADDR_MASK)
return 0;
page_reg = RSMU_SABRE_PAGE_ADDR;
page = reg & RSMU_PAGE_MASK;
/* The three page bits are located in the single Page Register */
buf[0] = (u8)((page >> 7) & 0x7);
bytes = 1;
break;
default:
dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
return -ENODEV;
}
/* Simply return if we are on the same page */
if (rsmu->page == page)
return 0;
err = rsmu_write_device(rsmu, page_reg, buf, bytes);
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_reg_read(void *context, unsigned int reg, unsigned int *val)
{
struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);
u8 addr = (u8)(reg & RSMU_ADDR_MASK);
int err;
err = rsmu_write_page_register(rsmu, reg);
if (err)
return err;
err = rsmu_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_reg_write(void *context, unsigned int reg, unsigned int val)
{
struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);
u8 addr = (u8)(reg & RSMU_ADDR_MASK);
u8 data = (u8)val;
int err;
err = rsmu_write_page_register(rsmu, reg);
if (err)
return err;
err = rsmu_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_cm_regmap_config = {
.reg_bits = 32,
.val_bits = 8,
.max_register = 0x20120000,
.reg_read = rsmu_reg_read,
.reg_write = rsmu_reg_write,
.cache_type = REGCACHE_NONE,
};
static const struct regmap_config rsmu_sabre_regmap_config = {
.reg_bits = 16,
.val_bits = 8,
.max_register = 0x400,
.reg_read = rsmu_reg_read,
.reg_write = rsmu_reg_write,
.cache_type = REGCACHE_NONE,
};
static int rsmu_spi_probe(struct spi_device *client)
{
const struct spi_device_id *id = spi_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;
spi_set_drvdata(client, rsmu);
rsmu->dev = &client->dev;
rsmu->type = (enum rsmu_type)id->driver_data;
/* Initialize regmap */
switch (rsmu->type) {
case RSMU_CM:
cfg = &rsmu_cm_regmap_config;
break;
case RSMU_SABRE:
cfg = &rsmu_sabre_regmap_config;
break;
default:
dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
return -ENODEV;
}
rsmu->regmap = devm_regmap_init(&client->dev, NULL, 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_spi_remove(struct spi_device *client)
{
struct rsmu_ddata *rsmu = spi_get_drvdata(client);
rsmu_core_exit(rsmu);
}
static const struct spi_device_id rsmu_spi_id[] = {
{ "8a34000", RSMU_CM },
{ "8a34001", RSMU_CM },
{ "82p33810", RSMU_SABRE },
{ "82p33811", RSMU_SABRE },
{}
};
MODULE_DEVICE_TABLE(spi, rsmu_spi_id);
static const struct of_device_id rsmu_spi_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 },
{}
};
MODULE_DEVICE_TABLE(of, rsmu_spi_of_match);
static struct spi_driver rsmu_spi_driver = {
.driver = {
.name = "rsmu-spi",
.of_match_table = rsmu_spi_of_match,
},
.probe = rsmu_spi_probe,
.remove = rsmu_spi_remove,
.id_table = rsmu_spi_id,
};
static int __init rsmu_spi_init(void)
{
return spi_register_driver(&rsmu_spi_driver);
}
subsys_initcall(rsmu_spi_init);
static void __exit rsmu_spi_exit(void)
{
spi_unregister_driver(&rsmu_spi_driver);
}
module_exit(rsmu_spi_exit);
MODULE_DESCRIPTION("Renesas SMU SPI driver");
MODULE_LICENSE("GPL");
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