linux/drivers/fmc/fmc-trivial.c
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   1/*
   2 * Copyright (C) 2012 CERN (www.cern.ch)
   3 * Author: Alessandro Rubini <rubini@gnudd.com>
   4 *
   5 * Permission to use, copy, modify, and/or distribute this software for any
   6 * purpose with or without fee is hereby granted, provided that the above
   7 * copyright notice and this permission notice appear in all copies.
   8 *
   9 * The software is provided "as is"; the copyright holders disclaim
  10 * all warranties and liabilities, to the extent permitted by
  11 * applicable law.
  12 */
  13
  14/* A trivial fmc driver that can load a gateware file and reports interrupts */
  15#include <linux/module.h>
  16#include <linux/init.h>
  17#include <linux/interrupt.h>
  18#include <linux/gpio.h>
  19#include <linux/fmc.h>
  20
  21static struct fmc_driver t_drv; /* initialized later */
  22
  23static irqreturn_t t_handler(int irq, void *dev_id)
  24{
  25        struct fmc_device *fmc = dev_id;
  26
  27        fmc->op->irq_ack(fmc);
  28        dev_info(&fmc->dev, "received irq %i\n", irq);
  29        return IRQ_HANDLED;
  30}
  31
  32static struct fmc_gpio t_gpio[] = {
  33        {
  34                .gpio = FMC_GPIO_IRQ(0),
  35                .mode = GPIOF_DIR_IN,
  36                .irqmode = IRQF_TRIGGER_RISING,
  37        }, {
  38                .gpio = FMC_GPIO_IRQ(1),
  39                .mode = GPIOF_DIR_IN,
  40                .irqmode = IRQF_TRIGGER_RISING,
  41        }
  42};
  43
  44static int t_probe(struct fmc_device *fmc)
  45{
  46        int ret;
  47        int index = 0;
  48
  49        if (fmc->op->validate)
  50                index = fmc->op->validate(fmc, &t_drv);
  51        if (index < 0)
  52                return -EINVAL; /* not our device: invalid */
  53
  54        ret = fmc->op->irq_request(fmc, t_handler, "fmc-trivial", IRQF_SHARED);
  55        if (ret < 0)
  56                return ret;
  57        /* ignore error code of call below, we really don't care */
  58        fmc->op->gpio_config(fmc, t_gpio, ARRAY_SIZE(t_gpio));
  59
  60        /* Reprogram, if asked to. ESRCH == no filename specified */
  61        ret = -ESRCH;
  62        if (fmc->op->reprogram)
  63                ret = fmc->op->reprogram(fmc, &t_drv, "");
  64        if (ret == -ESRCH)
  65                ret = 0;
  66        if (ret < 0)
  67                fmc->op->irq_free(fmc);
  68
  69        /* FIXME: reprogram LM32 too */
  70        return ret;
  71}
  72
  73static int t_remove(struct fmc_device *fmc)
  74{
  75        fmc->op->irq_free(fmc);
  76        return 0;
  77}
  78
  79static struct fmc_driver t_drv = {
  80        .version = FMC_VERSION,
  81        .driver.name = KBUILD_MODNAME,
  82        .probe = t_probe,
  83        .remove = t_remove,
  84        /* no table, as the current match just matches everything */
  85};
  86
  87 /* We accept the generic parameters */
  88FMC_PARAM_BUSID(t_drv);
  89FMC_PARAM_GATEWARE(t_drv);
  90
  91static int t_init(void)
  92{
  93        int ret;
  94
  95        ret = fmc_driver_register(&t_drv);
  96        return ret;
  97}
  98
  99static void t_exit(void)
 100{
 101        fmc_driver_unregister(&t_drv);
 102}
 103
 104module_init(t_init);
 105module_exit(t_exit);
 106
 107MODULE_LICENSE("Dual BSD/GPL");
 108
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