linux/drivers/gpio/gpio-max7301.c
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  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

  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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

105 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2006 Juergen Beisert, Pengutronix
* Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
* Copyright (C) 2009 Wolfram Sang, Pengutronix
*
* Check max730x.c for further details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/max7301.h>
/* A write to the MAX7301 means one message with one transfer */
static int max7301_spi_write(struct device *dev, unsigned int reg,
unsigned int val)
{
struct spi_device *spi = to_spi_device(dev);
u16 word = ((reg & 0x7F) << 8) | (val & 0xFF);
return spi_write_then_read(spi, &word, sizeof(word), NULL, 0);
}
/* A read from the MAX7301 means two transfers; here, one message each */
static int max7301_spi_read(struct device *dev, unsigned int reg)
{
int ret;
u16 word;
struct spi_device *spi = to_spi_device(dev);
word = 0x8000 | (reg << 8);
ret = spi_write_then_read(spi, &word, sizeof(word), &word,
sizeof(word));
if (ret)
return ret;
return word & 0xff;
}
static int max7301_probe(struct spi_device *spi)
{
struct max7301 *ts;
int ret;
/* bits_per_word cannot be configured in platform data */
spi->bits_per_word = 16;
ret = spi_setup(spi);
if (ret < 0)
return ret;
ts = devm_kzalloc(&spi->dev, sizeof(struct max7301), GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->read = max7301_spi_read;
ts->write = max7301_spi_write;
ts->dev = &spi->dev;
ret = __max730x_probe(ts);
return ret;
}
static int max7301_remove(struct spi_device *spi)
{
return __max730x_remove(&spi->dev);
}
static const struct spi_device_id max7301_id[] = {
{ "max7301", 0 },
{ }
};
MODULE_DEVICE_TABLE(spi, max7301_id);
static struct spi_driver max7301_driver = {
.driver = {
.name = "max7301",
},
.probe = max7301_probe,
.remove = max7301_remove,
.id_table = max7301_id,
};
static int __init max7301_init(void)
{
return spi_register_driver(&max7301_driver);
}
/* register after spi postcore initcall and before
* subsys initcalls that may rely on these GPIOs
*/
subsys_initcall(max7301_init);
static void __exit max7301_exit(void)
{
spi_unregister_driver(&max7301_driver);
}
module_exit(max7301_exit);
MODULE_AUTHOR("Juergen Beisert, Wolfram Sang");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MAX7301 GPIO-Expander");