linux/drivers/mfd/mc13xxx-spi.c
Uwe Kleine-König c39cf60feb mfd: mc13xxx: Make mc13xxx_common_exit() return void
Up to now mc13xxx_common_exit() returns zero unconditionally. Make it
return void instead which makes it easier to see in the callers that
there is no error to handle.

Also the return value of i2c and spi remove callbacks is ignored anyway.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211012153945.2651412-9-u.kleine-koenig@pengutronix.de
2021-11-05 14:40:26 +00:00

200 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2009-2010 Pengutronix
* Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
*
* loosely based on an earlier driver that has
* Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mfd/mc13xxx.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include "mc13xxx.h"
static const struct spi_device_id mc13xxx_device_id[] = {
{
.name = "mc13783",
.driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,
}, {
.name = "mc13892",
.driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,
}, {
.name = "mc34708",
.driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
static const struct of_device_id mc13xxx_dt_ids[] = {
{ .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },
{ .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },
{ .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
static const struct regmap_config mc13xxx_regmap_spi_config = {
.reg_bits = 7,
.pad_bits = 1,
.val_bits = 24,
.write_flag_mask = 0x80,
.max_register = MC13XXX_NUMREGS,
.cache_type = REGCACHE_NONE,
.use_single_read = true,
.use_single_write = true,
};
static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,
void *val, size_t val_size)
{
unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};
unsigned char r[4];
unsigned char *p = val;
struct device *dev = context;
struct spi_device *spi = to_spi_device(dev);
struct spi_transfer t = {
.tx_buf = w,
.rx_buf = r,
.len = 4,
};
struct spi_message m;
int ret;
if (val_size != 3 || reg_size != 1)
return -ENOTSUPP;
spi_message_init(&m);
spi_message_add_tail(&t, &m);
ret = spi_sync(spi, &m);
memcpy(p, &r[1], 3);
return ret;
}
static int mc13xxx_spi_write(void *context, const void *data, size_t count)
{
struct device *dev = context;
struct spi_device *spi = to_spi_device(dev);
const char *reg = data;
if (count != 4)
return -ENOTSUPP;
/* include errata fix for spi audio problems */
if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
spi_write(spi, data, count);
return spi_write(spi, data, count);
}
/*
* We cannot use regmap-spi generic bus implementation here.
* The MC13783 chip will get corrupted if CS signal is deasserted
* and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
* has the following errata (DSPhl22960):
* "The CSPI negates SS when the FIFO becomes empty with
* SSCTL= 0. Software cannot guarantee that the FIFO will not
* drain because of higher priority interrupts and the
* non-realtime characteristics of the operating system. As a
* result, the SS will negate before all of the data has been
* transferred to/from the peripheral."
* We workaround this by accessing the SPI controller with a
* single transfert.
*/
static struct regmap_bus regmap_mc13xxx_bus = {
.write = mc13xxx_spi_write,
.read = mc13xxx_spi_read,
};
static int mc13xxx_spi_probe(struct spi_device *spi)
{
struct mc13xxx *mc13xxx;
int ret;
mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
if (!mc13xxx)
return -ENOMEM;
dev_set_drvdata(&spi->dev, mc13xxx);
spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
mc13xxx->irq = spi->irq;
spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
ret = spi_setup(spi);
if (ret)
return ret;
mc13xxx->regmap = devm_regmap_init(&spi->dev, &regmap_mc13xxx_bus,
&spi->dev,
&mc13xxx_regmap_spi_config);
if (IS_ERR(mc13xxx->regmap)) {
ret = PTR_ERR(mc13xxx->regmap);
dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);
return ret;
}
if (spi->dev.of_node) {
const struct of_device_id *of_id =
of_match_device(mc13xxx_dt_ids, &spi->dev);
mc13xxx->variant = of_id->data;
} else {
const struct spi_device_id *id_entry = spi_get_device_id(spi);
mc13xxx->variant = (void *)id_entry->driver_data;
}
return mc13xxx_common_init(&spi->dev);
}
static int mc13xxx_spi_remove(struct spi_device *spi)
{
mc13xxx_common_exit(&spi->dev);
return 0;
}
static struct spi_driver mc13xxx_spi_driver = {
.id_table = mc13xxx_device_id,
.driver = {
.name = "mc13xxx",
.of_match_table = mc13xxx_dt_ids,
},
.probe = mc13xxx_spi_probe,
.remove = mc13xxx_spi_remove,
};
static int __init mc13xxx_init(void)
{
return spi_register_driver(&mc13xxx_spi_driver);
}
subsys_initcall(mc13xxx_init);
static void __exit mc13xxx_exit(void)
{
spi_unregister_driver(&mc13xxx_spi_driver);
}
module_exit(mc13xxx_exit);
MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
MODULE_LICENSE("GPL v2");