From 056d83f3c30c398f14eb879f1d1707e3a7808f4a Mon Sep 17 00:00:00 2001 From: Alessandro Rubini Date: Tue, 18 Jun 2013 23:47:46 +0200 Subject: [PATCH] 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: Alessandro Rubini Acked-by: Juan David Gonzalez Cobas Acked-by: Emilio G. Cota Acked-by: Samuel Iglesias Gonsalvez Signed-off-by: Greg Kroah-Hartman --- Documentation/fmc/00-INDEX | 3 + Documentation/fmc/fmc-trivial.txt | 17 +++++ drivers/fmc/Kconfig | 7 ++ drivers/fmc/Makefile | 1 + drivers/fmc/fmc-trivial.c | 107 ++++++++++++++++++++++++++++++ 5 files changed, 135 insertions(+) create mode 100644 Documentation/fmc/fmc-trivial.txt create mode 100644 drivers/fmc/fmc-trivial.c diff --git a/Documentation/fmc/00-INDEX b/Documentation/fmc/00-INDEX index 34df5cfc0c41..c22d6873fd08 100644 --- a/Documentation/fmc/00-INDEX +++ b/Documentation/fmc/00-INDEX @@ -27,3 +27,6 @@ identifiers.txt fmc-fakedev.txt - about drivers/fmc/fmc-fakedev.ko + +fmc-trivial.txt + - about drivers/fmc/fmc-trivial.ko diff --git a/Documentation/fmc/fmc-trivial.txt b/Documentation/fmc/fmc-trivial.txt new file mode 100644 index 000000000000..d1910bc67159 --- /dev/null +++ b/Documentation/fmc/fmc-trivial.txt @@ -0,0 +1,17 @@ +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. diff --git a/drivers/fmc/Kconfig b/drivers/fmc/Kconfig index 505e96b02a93..7eacef990be8 100644 --- a/drivers/fmc/Kconfig +++ b/drivers/fmc/Kconfig @@ -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 diff --git a/drivers/fmc/Makefile b/drivers/fmc/Makefile index 9832b79976b1..52624e6c0b1f 100644 --- a/drivers/fmc/Makefile +++ b/drivers/fmc/Makefile @@ -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 diff --git a/drivers/fmc/fmc-trivial.c b/drivers/fmc/fmc-trivial.c new file mode 100644 index 000000000000..6c590f54c79d --- /dev/null +++ b/drivers/fmc/fmc-trivial.c @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2012 CERN (www.cern.ch) + * Author: Alessandro Rubini + * + * 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 +#include +#include +#include +#include + +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"); -- 2.30.2