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https://github.com/torvalds/linux
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056d83f3c3
This simple do-nothing mezzanine driver shows how to write a mezzanine driver, that can also handle interrupts reported by the carrier. Signed-off-by: Alessandro Rubini <rubini@gnudd.com> Acked-by: Juan David Gonzalez Cobas <dcobas@cern.ch> Acked-by: Emilio G. Cota <cota@braap.org> Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
107 lines
2.4 KiB
C
107 lines
2.4 KiB
C
/*
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* Copyright (C) 2012 CERN (www.cern.ch)
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* Author: Alessandro Rubini <rubini@gnudd.com>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* The software is provided "as is"; the copyright holders disclaim
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* all warranties and liabilities, to the extent permitted by
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* applicable law.
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*/
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/* A trivial fmc driver that can load a gateware file and reports interrupts */
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/gpio.h>
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#include <linux/fmc.h>
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static struct fmc_driver t_drv; /* initialized later */
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static irqreturn_t t_handler(int irq, void *dev_id)
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{
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struct fmc_device *fmc = dev_id;
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fmc->op->irq_ack(fmc);
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dev_info(&fmc->dev, "received irq %i\n", irq);
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return IRQ_HANDLED;
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}
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static struct fmc_gpio t_gpio[] = {
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{
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.gpio = FMC_GPIO_IRQ(0),
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.mode = GPIOF_DIR_IN,
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.irqmode = IRQF_TRIGGER_RISING,
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}, {
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.gpio = FMC_GPIO_IRQ(1),
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.mode = GPIOF_DIR_IN,
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.irqmode = IRQF_TRIGGER_RISING,
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}
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};
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static int t_probe(struct fmc_device *fmc)
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{
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int ret;
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int index = 0;
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if (fmc->op->validate)
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index = fmc->op->validate(fmc, &t_drv);
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if (index < 0)
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return -EINVAL; /* not our device: invalid */
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ret = fmc->op->irq_request(fmc, t_handler, "fmc-trivial", IRQF_SHARED);
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if (ret < 0)
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return ret;
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/* ignore error code of call below, we really don't care */
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fmc->op->gpio_config(fmc, t_gpio, ARRAY_SIZE(t_gpio));
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/* Reprogram, if asked to. ESRCH == no filename specified */
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ret = -ESRCH;
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if (fmc->op->reprogram)
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ret = fmc->op->reprogram(fmc, &t_drv, "");
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if (ret == -ESRCH)
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ret = 0;
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if (ret < 0)
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fmc->op->irq_free(fmc);
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/* FIXME: reprogram LM32 too */
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return ret;
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}
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static int t_remove(struct fmc_device *fmc)
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{
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fmc->op->irq_free(fmc);
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return 0;
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}
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static struct fmc_driver t_drv = {
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.version = FMC_VERSION,
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.driver.name = KBUILD_MODNAME,
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.probe = t_probe,
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.remove = t_remove,
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/* no table, as the current match just matches everything */
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};
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/* We accept the generic parameters */
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FMC_PARAM_BUSID(t_drv);
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FMC_PARAM_GATEWARE(t_drv);
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static int t_init(void)
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{
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int ret;
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ret = fmc_driver_register(&t_drv);
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return ret;
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}
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static void t_exit(void)
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{
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fmc_driver_unregister(&t_drv);
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}
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module_init(t_init);
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module_exit(t_exit);
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MODULE_LICENSE("Dual BSD/GPL");
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