linux-stable/drivers/mfd/rsmu_spi.c
Uwe Kleine-König a0386bba70
spi: make remove callback a void function
The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-09 13:00:45 +00:00

271 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");