Commit 6c62a895 authored by Alessandro Rubini's avatar Alessandro Rubini Committed by Greg Kroah-Hartman
Browse files

FMC: add a software carrier driver 



This fake carrier is designed to help FMC users understand how a
carrier driver works, and to experiment the behaviour with EEPROM
reprogramming (with a mezzanine driver commited later). This carrier
can register up to 4 (fake) mezzanines.

We have real carriers (both on PCI-E and VME), but they are bigger
things and are not part of this submission.

Signed-off-by: default avatarAlessandro Rubini <rubini@gnudd.com>
Acked-by: default avatarJuan David Gonzalez Cobas <dcobas@cern.ch>
Acked-by: default avatarEmilio G. Cota <cota@braap.org>
Acked-by: default avatarSamuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 022c6747

Documentation/fmc/00-INDEX

+3 −0
Original line number Diff line number Diff line
@@ -24,3 +24,6 @@ mezzanine.txt 


identifiers.txt

	- how identification and matching works



fmc-fakedev.txt

	- about drivers/fmc/fmc-fakedev.ko

Documentation/fmc/fmc-fakedev.txt

0 → 100644
+36 −0
Original line number Diff line number Diff line 
fmc-fakedev

===========



This package includes a software-only device, called fmc-fakedev, which

is able to register up to 4 mezzanines (by default it registers one).

Unlike the SPEC driver, which creates an FMC device for each PCI cards

it manages, this module creates a single instance of its set of

mezzanines.



It is meant as the simplest possible example of how a driver should be

written, and it includes a fake EEPROM image (built using the tools

described in *note FMC Identification::),, which by default is

replicated for each fake mezzanine.



You can also use this device to verify the match algorithms, by asking

it to test your own EEPROM image. You can provide the image by means of

the eeprom= module parameter: the new EEPROM image is loaded, as usual,

by means of the firmware loader.  This example shows the defaults and a

custom EEPROM image:



     spusa.root# insmod fmc-fakedev.ko

     [   99.971247]  fake-fmc-carrier: mezzanine 0

     [   99.975393]       Manufacturer: fake-vendor

     [   99.979624]       Product name: fake-design-for-testing

     spusa.root# rmmod fmc-fakedev

     spusa.root# insmod fmc-fakedev.ko eeprom=fdelay-eeprom.bin

     [  121.447464]  fake-fmc-carrier: Mezzanine 0: eeprom "fdelay-eeprom.bin"

     [  121.462725]  fake-fmc-carrier: mezzanine 0

     [  121.466858]       Manufacturer: CERN

     [  121.470477]       Product name: FmcDelay1ns4cha

     spusa.root# rmmod fmc-fakedev



After loading the device, you can use the write_ee method do modify its

own internal fake EEPROM: whenever the image is overwritten starting at

offset 0, the module will unregister and register again the FMC device.

This is shown in fmc-write-eeprom.txt

drivers/fmc/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -15,3 +15,14 @@ menuconfig FMC 
	  The framework was born outside of the kernel and at this time

	  the off-tree code base is more complete.  Code and documentation

	  is at git://ohwr.org/fmc-projects/fmc-bus.git .



if FMC



config FMC_FAKEDEV

	tristate "FMC fake device (software testing)"

	help

	  This is a fake carrier, bringing a default EEPROM content

	  that can be rewritten at run time and usef for matching

	  mezzanines.



endif # FMC

drivers/fmc/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -6,3 +6,5 @@ fmc-y += fmc-match.o 
fmc-y += fmc-sdb.o

fmc-y += fru-parse.o

fmc-y += fmc-dump.o



obj-$(CONFIG_FMC_FAKEDEV) += fmc-fakedev.o

drivers/fmc/fmc-fakedev.c

0 → 100644
+355 −0
Original line number Diff line number Diff line 
/*

 * 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.

 */

#include <linux/module.h>

#include <linux/init.h>

#include <linux/string.h>

#include <linux/device.h>

#include <linux/slab.h>

#include <linux/firmware.h>

#include <linux/workqueue.h>

#include <linux/err.h>

#include <linux/fmc.h>



#define FF_EEPROM_SIZE		8192	/* The standard eeprom size */

#define FF_MAX_MEZZANINES	4	/* Fakes a multi-mezzanine carrier */



/* The user can pass up to 4 names of eeprom images to load */

static char *ff_eeprom[FF_MAX_MEZZANINES];

static int ff_nr_eeprom;

module_param_array_named(eeprom, ff_eeprom, charp, &ff_nr_eeprom, 0444);



/* The user can ask for a multi-mezzanine carrier, with the default eeprom */

static int ff_nr_dev = 1;

module_param_named(ndev, ff_nr_dev, int, 0444);





/* Lazily, don't support the "standard" module parameters */



/*

 * Eeprom built from these commands:



	../fru-generator -v fake-vendor -n fake-design-for-testing \

		-s 01234 -p none > IPMI-FRU



	gensdbfs . ../fake-eeprom.bin

*/

static char ff_eeimg[FF_MAX_MEZZANINES][FF_EEPROM_SIZE] = {

	{

	0x01, 0x00, 0x00, 0x01, 0x00, 0x0c, 0x00, 0xf2, 0x01, 0x0b, 0x00, 0xb2,

	0x86, 0x87, 0xcb, 0x66, 0x61, 0x6b, 0x65, 0x2d, 0x76, 0x65, 0x6e, 0x64,

	0x6f, 0x72, 0xd7, 0x66, 0x61, 0x6b, 0x65, 0x2d, 0x64, 0x65, 0x73, 0x69,

	0x67, 0x6e, 0x2d, 0x66, 0x6f, 0x72, 0x2d, 0x74, 0x65, 0x73, 0x74, 0x69,

	0x6e, 0x67, 0xc5, 0x30, 0x31, 0x32, 0x33, 0x34, 0xc4, 0x6e, 0x6f, 0x6e,

	0x65, 0xda, 0x32, 0x30, 0x31, 0x32, 0x2d, 0x31, 0x31, 0x2d, 0x31, 0x39,

	0x20, 0x32, 0x32, 0x3a, 0x34, 0x32, 0x3a, 0x33, 0x30, 0x2e, 0x30, 0x37,

	0x34, 0x30, 0x35, 0x35, 0xc1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87,

	0x02, 0x02, 0x0d, 0xf7, 0xf8, 0x02, 0xb0, 0x04, 0x74, 0x04, 0xec, 0x04,

	0x00, 0x00, 0x00, 0x00, 0xe8, 0x03, 0x02, 0x02, 0x0d, 0x5c, 0x93, 0x01,

	0x4a, 0x01, 0x39, 0x01, 0x5a, 0x01, 0x00, 0x00, 0x00, 0x00, 0xb8, 0x0b,

	0x02, 0x02, 0x0d, 0x63, 0x8c, 0x00, 0xfa, 0x00, 0xed, 0x00, 0x06, 0x01,

	0x00, 0x00, 0x00, 0x00, 0xa0, 0x0f, 0x01, 0x02, 0x0d, 0xfb, 0xf5, 0x05,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x01, 0x02, 0x0d, 0xfc, 0xf4, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x0d, 0xfd, 0xf3, 0x03,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0xfa, 0x82, 0x0b, 0xea, 0x8f, 0xa2, 0x12, 0x00, 0x00, 0x1e, 0x44, 0x00,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x00, 0x00, 0x53, 0x44, 0x42, 0x2d, 0x00, 0x03, 0x01, 0x01,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x01, 0xc4, 0x46, 0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61,

	0x2e, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,

	0x2e, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,

	0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xc0,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xc4, 0x46, 0x69, 0x6c, 0x65,

	0x44, 0x61, 0x74, 0x61, 0x6e, 0x61, 0x6d, 0x65, 0x00, 0x00, 0x00, 0x01,

	0x00, 0x00, 0x00, 0x00, 0x6e, 0x61, 0x6d, 0x65, 0x20, 0x20, 0x20, 0x20,

	0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x01,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00,

	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xdf,

	0x46, 0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61, 0x49, 0x50, 0x4d, 0x49,

	0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x49, 0x50, 0x4d, 0x49,

	0x2d, 0x46, 0x52, 0x55, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,

	0x20, 0x20, 0x20, 0x01, 0x66, 0x61, 0x6b, 0x65, 0x0a,

	},

};



struct ff_dev {

	struct fmc_device *fmc[FF_MAX_MEZZANINES];

	struct device dev;

};



static struct ff_dev *ff_current_dev; /* We have 1 carrier, 1 slot */



static int ff_reprogram(struct fmc_device *fmc, struct fmc_driver *drv,

			  char *gw)

{

	const struct firmware *fw;

	int ret;



	if (!gw) {

		/* program golden: success */

		fmc->flags &= ~FMC_DEVICE_HAS_CUSTOM;

		fmc->flags |= FMC_DEVICE_HAS_GOLDEN;

		return 0;

	}



	dev_info(&fmc->dev, "reprogramming with %s\n", gw);

	ret = request_firmware(&fw, gw, &fmc->dev);

	if (ret < 0) {

		dev_warn(&fmc->dev, "request firmware \"%s\": error %i\n",

			 gw, ret);

		goto out;

	}

	fmc->flags &= ~FMC_DEVICE_HAS_GOLDEN;

	fmc->flags |= FMC_DEVICE_HAS_CUSTOM;



out:

	release_firmware(fw);

	return ret;

}



static int ff_irq_request(struct fmc_device *fmc, irq_handler_t handler,

			    char *name, int flags)

{

	return -EOPNOTSUPP;

}



/* FIXME: should also have some fake FMC GPIO mapping */





/*

 * This work function is called when we changed the eeprom. It removes the

 * current fmc device and registers a new one, with different identifiers.

 */

static struct ff_dev *ff_dev_create(void); /* defined later */



static void ff_work_fn(struct work_struct *work)

{

	struct ff_dev *ff = ff_current_dev;

	int ret;



	fmc_device_unregister_n(ff->fmc, ff_nr_dev);

	device_unregister(&ff->dev);

	ff_current_dev = NULL;



	ff = ff_dev_create();

	if (IS_ERR(ff)) {

		pr_warning("%s: can't re-create FMC devices\n", __func__);

		return;

	}

	ret = fmc_device_register_n(ff->fmc, ff_nr_dev);

	if (ret < 0) {

		dev_warn(&ff->dev, "can't re-register FMC devices\n");

		device_unregister(&ff->dev);

		return;

	}



	ff_current_dev = ff;

}



static DECLARE_DELAYED_WORK(ff_work, ff_work_fn);





/* low-level i2c */

static int ff_eeprom_read(struct fmc_device *fmc, uint32_t offset,

		void *buf, size_t size)

{

	if (offset > FF_EEPROM_SIZE)

		return -EINVAL;

	if (offset + size > FF_EEPROM_SIZE)

		size = FF_EEPROM_SIZE - offset;

	memcpy(buf, fmc->eeprom + offset, size);

	return size;

}



static int ff_eeprom_write(struct fmc_device *fmc, uint32_t offset,

		    const void *buf, size_t size)

{

	if (offset > FF_EEPROM_SIZE)

		return -EINVAL;

	if (offset + size > FF_EEPROM_SIZE)

		size = FF_EEPROM_SIZE - offset;

	dev_info(&fmc->dev, "write_eeprom: offset %i, size %zi\n",

		 (int)offset, size);

	memcpy(fmc->eeprom + offset, buf, size);

	schedule_delayed_work(&ff_work, HZ * 2); /* remove, replug, in 2s */

	return size;

}



/* i2c operations for fmc */

static int ff_read_ee(struct fmc_device *fmc, int pos, void *data, int len)

{

	if (!(fmc->flags & FMC_DEVICE_HAS_GOLDEN))

		return -EOPNOTSUPP;

	return ff_eeprom_read(fmc, pos, data, len);

}



static int ff_write_ee(struct fmc_device *fmc, int pos,

			 const void *data, int len)

{

	if (!(fmc->flags & FMC_DEVICE_HAS_GOLDEN))

		return -EOPNOTSUPP;

	return ff_eeprom_write(fmc, pos, data, len);

}



/* readl and writel do not do anything. Don't waste RAM with "base" */

static uint32_t ff_readl(struct fmc_device *fmc, int offset)

{

	return 0;

}



static void ff_writel(struct fmc_device *fmc, uint32_t value, int offset)

{

	return;

}



/* validate is useful so fmc-write-eeprom will not reprogram every 2 seconds */

static int ff_validate(struct fmc_device *fmc, struct fmc_driver *drv)

{

	int i;



	if (!drv->busid_n)

		return 0; /* everyhing is valid */

	for (i = 0; i < drv->busid_n; i++)

		if (drv->busid_val[i] == fmc->device_id)

			return i;

	return -ENOENT;

}







static struct fmc_operations ff_fmc_operations = {

	.readl =		ff_readl,

	.writel =		ff_writel,

	.reprogram =		ff_reprogram,

	.irq_request =		ff_irq_request,

	.read_ee =		ff_read_ee,

	.write_ee =		ff_write_ee,

	.validate =		ff_validate,

};



/* This device is kmalloced: release it */

static void ff_dev_release(struct device *dev)

{

	struct ff_dev *ff = container_of(dev, struct ff_dev, dev);

	kfree(ff);

}



static struct fmc_device ff_template_fmc = {

	.version = FMC_VERSION,

	.owner = THIS_MODULE,

	.carrier_name = "fake-fmc-carrier",

	.device_id = 0xf001, /* fool */

	.eeprom_len = sizeof(ff_eeimg[0]),

	.memlen = 0x1000, /* 4k, to show something */

	.op = &ff_fmc_operations,

	.hwdev = NULL, /* filled at creation time */

	.flags = FMC_DEVICE_HAS_GOLDEN,

};



static struct ff_dev *ff_dev_create(void)

{

	struct ff_dev *ff;

	struct fmc_device *fmc;

	int i, ret;



	ff = kzalloc(sizeof(*ff), GFP_KERNEL);

	if (!ff)

		return ERR_PTR(-ENOMEM);

	dev_set_name(&ff->dev, "fake-fmc-carrier");

	ff->dev.release = ff_dev_release;



	ret = device_register(&ff->dev);

	if (ret < 0) {

		put_device(&ff->dev);

		return ERR_PTR(ret);

	}



	/* Create fmc structures that refer to this new "hw" device */

	for (i = 0; i < ff_nr_dev; i++) {

		fmc = kmemdup(&ff_template_fmc, sizeof(ff_template_fmc),

			      GFP_KERNEL);

		fmc->hwdev = &ff->dev;

		fmc->carrier_data = ff;

		fmc->nr_slots = ff_nr_dev;

		/* the following fields are different for each slot */

		fmc->eeprom = ff_eeimg[i];

		fmc->eeprom_addr = 0x50 + 2 * i;

		fmc->slot_id = i;

		ff->fmc[i] = fmc;

		/* increment the identifier, each must be different */

		ff_template_fmc.device_id++;

	}

	return ff;

}



/* init and exit */

static int ff_init(void)

{

	struct ff_dev *ff;

	const struct firmware *fw;

	int i, len, ret = 0;



	/* Replicate the default eeprom for the max number of mezzanines */

	for (i = 1; i < FF_MAX_MEZZANINES; i++)

		memcpy(ff_eeimg[i], ff_eeimg[0], sizeof(ff_eeimg[0]));



	if (ff_nr_eeprom > ff_nr_dev)

		ff_nr_dev = ff_nr_eeprom;



	ff = ff_dev_create();

	if (IS_ERR(ff))

		return PTR_ERR(ff);



	/* If the user passed "eeprom=" as a parameter, fetch them */

	for (i = 0; i < ff_nr_eeprom; i++) {

		if (!strlen(ff_eeprom[i]))

			continue;

		ret = request_firmware(&fw, ff_eeprom[i], &ff->dev);

		if (ret < 0) {

			dev_err(&ff->dev, "Mezzanine %i: can't load \"%s\" "

				"(error %i)\n", i, ff_eeprom[i], -ret);

		} else {

			len = min_t(size_t, fw->size, (size_t)FF_EEPROM_SIZE);

			memcpy(ff_eeimg[i], fw->data, len);

			release_firmware(fw);

			dev_info(&ff->dev, "Mezzanine %i: eeprom \"%s\"\n", i,

				ff_eeprom[i]);

		}

	}



	ret = fmc_device_register_n(ff->fmc, ff_nr_dev);

	if (ret) {

		device_unregister(&ff->dev);

		return ret;

	}

	ff_current_dev = ff;

	return ret;

}



static void ff_exit(void)

{

	if (ff_current_dev) {

		fmc_device_unregister_n(ff_current_dev->fmc, ff_nr_dev);

		device_unregister(&ff_current_dev->dev);

	}

	cancel_delayed_work_sync(&ff_work);

}



module_init(ff_init);

module_exit(ff_exit);



MODULE_LICENSE("Dual BSD/GPL");

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