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products/Sources/formale Sprachen/C/Linux/drivers/media/i2c/   (Linux Kernel Version 6.17.9©)  Datei vom 24.10.2025 mit Größe 31 kB image not shown  

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gpio-mc33880.c


products/Sources/formale Sprachen/C/Linux/drivers/gpio/gpio-mc33880.c

// SPDX-License-Identifier: GPL-2.0-only /* * MC33880 high-side/low-side switch GPIO driver * Copyright (c) 2009 Intel Corporation */ /* Supports: * Freescale MC33880 high-side/low-side switch */ #include #include #include #include #include #include #include #define DRIVER_NAME "mc33880" /* * Pin configurations, see MAX7301 datasheet page 6 */ #define PIN_CONFIG_MASK 0x03 #define PIN_CONFIG_IN_PULLUP 0x03 #define PIN_CONFIG_IN_WO_PULLUP 0x02 #define PIN_CONFIG_OUT 0x01 #define PIN_NUMBER 8 /* * Some registers must be read back to modify. * To save time we cache them here in memory */ struct mc33880 { struct mutex lock; /* protect from simultaneous accesses */ u8 port_config; struct gpio_chip chip; struct spi_device *spi; }; static int mc33880_write_config(struct mc33880 *mc) { return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config)); } static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value) { if (value) mc->port_config |= 1 << offset; else mc->port_config &= ~(1 << offset); return mc33880_write_config(mc); } static int mc33880_set(struct gpio_chip *chip, unsigned int offset, int value) { struct mc33880 *mc = gpiochip_get_data(chip); int ret; mutex_lock(&mc->lock); ret = __mc33880_set(mc, offset, value); mutex_unlock(&mc->lock); return ret; } static int mc33880_probe(struct spi_device *spi) { struct mc33880 *mc; struct mc33880_platform_data *pdata; int ret; pdata = dev_get_platdata(&spi->dev); if (!pdata || !pdata->base) { dev_dbg(&spi->dev, "incorrect or missing platform data\n"); return -EINVAL; } /* * bits_per_word cannot be configured in platform data */ spi->bits_per_word = 8; ret = spi_setup(spi); if (ret < 0) return ret; mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL); if (!mc) return -ENOMEM; mutex_init(&mc->lock); spi_set_drvdata(spi, mc); mc->spi = spi; mc->chip.label = DRIVER_NAME; mc->chip.set = mc33880_set; mc->chip.base = pdata->base; mc->chip.ngpio = PIN_NUMBER; mc->chip.can_sleep = true; mc->chip.parent = &spi->dev; mc->chip.owner = THIS_MODULE; mc->port_config = 0x00; /* write twice, because during initialisation the first setting * is just for testing SPI communication, and the second is the * "real" configuration */ ret = mc33880_write_config(mc); mc->port_config = 0x00; if (!ret) ret = mc33880_write_config(mc); if (ret) { dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n", ret); goto exit_destroy; } ret = gpiochip_add_data(&mc->chip, mc); if (ret) goto exit_destroy; return ret; exit_destroy: mutex_destroy(&mc->lock); return ret; } static void mc33880_remove(struct spi_device *spi) { struct mc33880 *mc; mc = spi_get_drvdata(spi); gpiochip_remove(&mc->chip); mutex_destroy(&mc->lock); } static struct spi_driver mc33880_driver = { .driver = { .name = DRIVER_NAME, }, .probe = mc33880_probe, .remove = mc33880_remove, }; static int __init mc33880_init(void) { return spi_register_driver(&mc33880_driver); } /* register after spi postcore initcall and before * subsys initcalls that may rely on these GPIOs */ subsys_initcall(mc33880_init); static void __exit mc33880_exit(void) { spi_unregister_driver(&mc33880_driver); } module_exit(mc33880_exit); MODULE_AUTHOR("Mocean Laboratories "); MODULE_DESCRIPTION("MC33880 high-side/low-side switch GPIO driver"); MODULE_LICENSE("GPL v2");

                                                                                                                                                                                                                                                                                                                                                                                                     

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