82c298100a
Based on 1 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 distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 44 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170025.980374610@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
177 lines
3.5 KiB
C
177 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* MC33880 high-side/low-side switch GPIO driver
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* Copyright (c) 2009 Intel Corporation
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*/
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/* Supports:
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* Freescale MC33880 high-side/low-side switch
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*/
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/mc33880.h>
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#include <linux/gpio/driver.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#define DRIVER_NAME "mc33880"
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/*
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* Pin configurations, see MAX7301 datasheet page 6
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*/
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#define PIN_CONFIG_MASK 0x03
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#define PIN_CONFIG_IN_PULLUP 0x03
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#define PIN_CONFIG_IN_WO_PULLUP 0x02
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#define PIN_CONFIG_OUT 0x01
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#define PIN_NUMBER 8
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/*
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* Some registers must be read back to modify.
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* To save time we cache them here in memory
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*/
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struct mc33880 {
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struct mutex lock; /* protect from simultaneous accesses */
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u8 port_config;
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struct gpio_chip chip;
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struct spi_device *spi;
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};
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static int mc33880_write_config(struct mc33880 *mc)
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{
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return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
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}
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static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
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{
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if (value)
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mc->port_config |= 1 << offset;
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else
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mc->port_config &= ~(1 << offset);
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return mc33880_write_config(mc);
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}
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static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct mc33880 *mc = gpiochip_get_data(chip);
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mutex_lock(&mc->lock);
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__mc33880_set(mc, offset, value);
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mutex_unlock(&mc->lock);
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}
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static int mc33880_probe(struct spi_device *spi)
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{
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struct mc33880 *mc;
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struct mc33880_platform_data *pdata;
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int ret;
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pdata = dev_get_platdata(&spi->dev);
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if (!pdata || !pdata->base) {
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dev_dbg(&spi->dev, "incorrect or missing platform data\n");
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return -EINVAL;
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}
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/*
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* bits_per_word cannot be configured in platform data
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*/
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spi->bits_per_word = 8;
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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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mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
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if (!mc)
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return -ENOMEM;
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mutex_init(&mc->lock);
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spi_set_drvdata(spi, mc);
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mc->spi = spi;
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mc->chip.label = DRIVER_NAME,
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mc->chip.set = mc33880_set;
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mc->chip.base = pdata->base;
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mc->chip.ngpio = PIN_NUMBER;
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mc->chip.can_sleep = true;
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mc->chip.parent = &spi->dev;
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mc->chip.owner = THIS_MODULE;
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mc->port_config = 0x00;
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/* write twice, because during initialisation the first setting
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* is just for testing SPI communication, and the second is the
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* "real" configuration
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*/
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ret = mc33880_write_config(mc);
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mc->port_config = 0x00;
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if (!ret)
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ret = mc33880_write_config(mc);
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if (ret) {
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dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
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ret);
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goto exit_destroy;
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}
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ret = gpiochip_add_data(&mc->chip, mc);
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if (ret)
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goto exit_destroy;
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return ret;
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exit_destroy:
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mutex_destroy(&mc->lock);
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return ret;
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}
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static int mc33880_remove(struct spi_device *spi)
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{
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struct mc33880 *mc;
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mc = spi_get_drvdata(spi);
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if (!mc)
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return -ENODEV;
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gpiochip_remove(&mc->chip);
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mutex_destroy(&mc->lock);
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return 0;
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}
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static struct spi_driver mc33880_driver = {
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.driver = {
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.name = DRIVER_NAME,
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},
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.probe = mc33880_probe,
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.remove = mc33880_remove,
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};
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static int __init mc33880_init(void)
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{
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return spi_register_driver(&mc33880_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(mc33880_init);
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static void __exit mc33880_exit(void)
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{
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spi_unregister_driver(&mc33880_driver);
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}
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module_exit(mc33880_exit);
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MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
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MODULE_LICENSE("GPL v2");
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