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06de2cd788
An spi or i2c remove callback is only called for devices that probed successfully. In this case this implies that __max730x_probe() set a non-NULL driver data. So the check ts == NULL is never true. With this check dropped, __max730x_remove() 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: Bartosz Golaszewski <brgl@bgdev.pl>
107 lines
2.3 KiB
C
107 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2006 Juergen Beisert, Pengutronix
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* Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
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* Copyright (C) 2009 Wolfram Sang, Pengutronix
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*
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* Check max730x.c for further details.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/max7301.h>
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/* A write to the MAX7301 means one message with one transfer */
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static int max7301_spi_write(struct device *dev, unsigned int reg,
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unsigned int val)
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{
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struct spi_device *spi = to_spi_device(dev);
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u16 word = ((reg & 0x7F) << 8) | (val & 0xFF);
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return spi_write_then_read(spi, &word, sizeof(word), NULL, 0);
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}
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/* A read from the MAX7301 means two transfers; here, one message each */
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static int max7301_spi_read(struct device *dev, unsigned int reg)
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{
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int ret;
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u16 word;
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struct spi_device *spi = to_spi_device(dev);
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word = 0x8000 | (reg << 8);
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ret = spi_write_then_read(spi, &word, sizeof(word), &word,
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sizeof(word));
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if (ret)
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return ret;
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return word & 0xff;
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}
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static int max7301_probe(struct spi_device *spi)
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{
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struct max7301 *ts;
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int ret;
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/* bits_per_word cannot be configured in platform data */
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spi->bits_per_word = 16;
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ret = spi_setup(spi);
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if (ret < 0)
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return ret;
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ts = devm_kzalloc(&spi->dev, sizeof(struct max7301), GFP_KERNEL);
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if (!ts)
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return -ENOMEM;
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ts->read = max7301_spi_read;
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ts->write = max7301_spi_write;
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ts->dev = &spi->dev;
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ret = __max730x_probe(ts);
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return ret;
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}
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static int max7301_remove(struct spi_device *spi)
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{
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__max730x_remove(&spi->dev);
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return 0;
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}
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static const struct spi_device_id max7301_id[] = {
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{ "max7301", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(spi, max7301_id);
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static struct spi_driver max7301_driver = {
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.driver = {
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.name = "max7301",
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},
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.probe = max7301_probe,
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.remove = max7301_remove,
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.id_table = max7301_id,
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};
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static int __init max7301_init(void)
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{
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return spi_register_driver(&max7301_driver);
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}
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/* register after spi postcore initcall and before
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* subsys initcalls that may rely on these GPIOs
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*/
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subsys_initcall(max7301_init);
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static void __exit max7301_exit(void)
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{
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spi_unregister_driver(&max7301_driver);
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}
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module_exit(max7301_exit);
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MODULE_AUTHOR("Juergen Beisert, Wolfram Sang");
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("MAX7301 GPIO-Expander");
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