kernel-ark/drivers/mfd/mc13xxx-spi.c
Uwe Kleine-König 8b8495532c mfd: Drop modifying mc13xxx driver's id_table in probe
This was introduced in commit

        876989d (mfd: Add device tree probe support for mc13xxx)

for spi and later while introducing support for i2c copied to the i2c
driver.

Modifying driver details is very strange, for example probing an
mc13892 device (instantiated via dt) removes the driver's ability to
handle (traditionally probed) mc13783 devices in this case.
I'm not aware of any problems that make this hack necessary and if
there were some, they'd have to be fixed in the spi/i2c core, not in
a driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2012-07-16 15:40:17 +02:00

197 lines
4.8 KiB
C

/*
* 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>
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mutex.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 = MC13XXX_ID_MC13783,
}, {
.name = "mc13892",
.driver_data = MC13XXX_ID_MC13892,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
static const struct of_device_id mc13xxx_dt_ids[] = {
{ .compatible = "fsl,mc13783", .data = (void *) MC13XXX_ID_MC13783, },
{ .compatible = "fsl,mc13892", .data = (void *) MC13XXX_ID_MC13892, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
static 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_rw = 1,
};
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);
if (count != 4)
return -ENOTSUPP;
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;
struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev);
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->dev = &spi->dev;
mutex_init(&mc13xxx->lock);
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(mc13xxx->dev, "Failed to initialize register map: %d\n",
ret);
dev_set_drvdata(&spi->dev, NULL);
return ret;
}
ret = mc13xxx_common_init(mc13xxx, pdata, spi->irq);
if (ret) {
dev_set_drvdata(&spi->dev, NULL);
} else {
const struct spi_device_id *devid =
spi_get_device_id(spi);
if (!devid || devid->driver_data != mc13xxx->ictype)
dev_warn(mc13xxx->dev,
"device id doesn't match auto detection!\n");
}
return ret;
}
static int __devexit mc13xxx_spi_remove(struct spi_device *spi)
{
struct mc13xxx *mc13xxx = dev_get_drvdata(&spi->dev);
mc13xxx_common_cleanup(mc13xxx);
return 0;
}
static struct spi_driver mc13xxx_spi_driver = {
.id_table = mc13xxx_device_id,
.driver = {
.name = "mc13xxx",
.owner = THIS_MODULE,
.of_match_table = mc13xxx_dt_ids,
},
.probe = mc13xxx_spi_probe,
.remove = __devexit_p(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");