Commit 056d83f3 authored by Alessandro Rubini's avatar Alessandro Rubini Committed by Greg Kroah-Hartman

FMC: add a software mezzanine driver

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: 's avatarAlessandro Rubini <rubini@gnudd.com>
Acked-by: 's avatarJuan David Gonzalez Cobas <dcobas@cern.ch>
Acked-by: 's avatarEmilio G. Cota <cota@braap.org>
Acked-by: 's avatarSamuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6c62a895
......@@ -27,3 +27,6 @@ identifiers.txt
fmc-fakedev.txt
- about drivers/fmc/fmc-fakedev.ko
fmc-trivial.txt
- about drivers/fmc/fmc-trivial.ko
fmc-trivial
===========
The simple module fmc-trivial is just a simple client that registers an
interrupt handler. I used it to verify the basic mechanism of the FMC
bus and how interrupts worked.
The module implements the generic FMC parameters, so it can program a
different gateware file in each card. The whole list of parameters it
accepts are:
`busid='
`gateware='
Generic parameters. See mezzanine.txt
This driver is worth reading, in my opinion.
......@@ -25,4 +25,11 @@ config FMC_FAKEDEV
that can be rewritten at run time and usef for matching
mezzanines.
config FMC_TRIVIAL
tristate "FMC trivial mezzanine driver (software testing)"
help
This is a fake mezzanine driver, to show how FMC works and test it.
The driver also handles interrupts (we used it with a real carrier
before the mezzanines were produced)
endif # FMC
......@@ -8,3 +8,4 @@ fmc-y += fru-parse.o
fmc-y += fmc-dump.o
obj-$(CONFIG_FMC_FAKEDEV) += fmc-fakedev.o
obj-$(CONFIG_FMC_TRIVIAL) += fmc-trivial.o
/*
* Copyright (C) 2012 CERN (www.cern.ch)
* Author: Alessandro Rubini <rubini@gnudd.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* The software is provided "as is"; the copyright holders disclaim
* all warranties and liabilities, to the extent permitted by
* applicable law.
*/
/* A trivial fmc driver that can load a gateware file and reports interrupts */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/fmc.h>
static struct fmc_driver t_drv; /* initialized later */
static irqreturn_t t_handler(int irq, void *dev_id)
{
struct fmc_device *fmc = dev_id;
fmc->op->irq_ack(fmc);
dev_info(&fmc->dev, "received irq %i\n", irq);
return IRQ_HANDLED;
}
static struct fmc_gpio t_gpio[] = {
{
.gpio = FMC_GPIO_IRQ(0),
.mode = GPIOF_DIR_IN,
.irqmode = IRQF_TRIGGER_RISING,
}, {
.gpio = FMC_GPIO_IRQ(1),
.mode = GPIOF_DIR_IN,
.irqmode = IRQF_TRIGGER_RISING,
}
};
static int t_probe(struct fmc_device *fmc)
{
int ret;
int index = 0;
if (fmc->op->validate)
index = fmc->op->validate(fmc, &t_drv);
if (index < 0)
return -EINVAL; /* not our device: invalid */
ret = fmc->op->irq_request(fmc, t_handler, "fmc-trivial", IRQF_SHARED);
if (ret < 0)
return ret;
/* ignore error code of call below, we really don't care */
fmc->op->gpio_config(fmc, t_gpio, ARRAY_SIZE(t_gpio));
/* Reprogram, if asked to. ESRCH == no filename specified */
ret = -ESRCH;
if (fmc->op->reprogram)
ret = fmc->op->reprogram(fmc, &t_drv, "");
if (ret == -ESRCH)
ret = 0;
if (ret < 0)
fmc->op->irq_free(fmc);
/* FIXME: reprogram LM32 too */
return ret;
}
static int t_remove(struct fmc_device *fmc)
{
fmc->op->irq_free(fmc);
return 0;
}
static struct fmc_driver t_drv = {
.version = FMC_VERSION,
.driver.name = KBUILD_MODNAME,
.probe = t_probe,
.remove = t_remove,
/* no table, as the current match just matches everything */
};
/* We accept the generic parameters */
FMC_PARAM_BUSID(t_drv);
FMC_PARAM_GATEWARE(t_drv);
static int t_init(void)
{
int ret;
ret = fmc_driver_register(&t_drv);
return ret;
}
static void t_exit(void)
{
fmc_driver_unregister(&t_drv);
}
module_init(t_init);
module_exit(t_exit);
MODULE_LICENSE("Dual BSD/GPL");
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