272 lines
6.4 KiB
C
272 lines
6.4 KiB
C
// 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_HIGHER_ADDR_MASK 0xFF80
|
|
#define RSMU_HIGHER_ADDR_SHIFT 7
|
|
#define RSMU_LOWER_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[256] = {0};
|
|
u8 rsp[256] = {0};
|
|
int ret;
|
|
|
|
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[256] = {0};
|
|
|
|
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, u16 reg)
|
|
{
|
|
u8 page_reg;
|
|
u8 buf[2];
|
|
u16 bytes;
|
|
u16 page;
|
|
int err;
|
|
|
|
switch (rsmu->type) {
|
|
case RSMU_CM:
|
|
page_reg = RSMU_CM_PAGE_ADDR;
|
|
page = reg & RSMU_HIGHER_ADDR_MASK;
|
|
buf[0] = (u8)(page & 0xff);
|
|
buf[1] = (u8)((page >> 8) & 0xff);
|
|
bytes = 2;
|
|
break;
|
|
case RSMU_SABRE:
|
|
page_reg = RSMU_SABRE_PAGE_ADDR;
|
|
page = reg >> RSMU_HIGHER_ADDR_SHIFT;
|
|
buf[0] = (u8)(page & 0xff);
|
|
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_LOWER_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_LOWER_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 = 16,
|
|
.val_bits = 8,
|
|
.max_register = 0xD000,
|
|
.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 = of_match_ptr(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");
|