From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cassiel.sirena.org.uk ([80.68.93.111]) by canuck.infradead.org with esmtps (Exim 4.54 #1 (Red Hat Linux)) id 1EucQO-0006vF-4W for linux-mtd@lists.infradead.org; Thu, 05 Jan 2006 16:13:43 -0500 Date: Thu, 5 Jan 2006 21:09:54 +0000 From: Mark Brown To: Deepak Saxena Message-ID: <20060105210954.GA8423@sirena.org.uk> References: <20051229232138.GA32463@plexity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051229232138.GA32463@plexity.net> Cc: linux-mtd@lists.infradead.org Subject: Re: [RFC] Make physmap into a platform device driver... List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , [Resent without GPG signature since the list software rejected my mail due to a "suspicious header".] On Thu, Dec 29, 2005 at 03:21:38PM -0800, Deepak Saxena wrote: > MTD layer and have the physmap driver use it. The physmap driver > could register itself as a platform driver for "phys-mtd" devices > and boards would just fill in platform_device structure with the > appropriate resource window and the needed fields below as the > platform_data. We may want to trim down the structure to remove > ARM-specific fields and let ARM have it's own structure that contains > the generic structure as a member. Thoughts? An alternative approach (which Jason Gunthorpe posted a patch for recently IIRC) is to add probe support to the plat-ram driver so it can work with any kind of chip. I have a patch kicking around doing pretty much that but also renaming the driver to make it look less strange when used. My patch is below - it probably ought to have the re-addition of write protection methods which I had stripped out since I've got partially written support for paging in chips and thought the two might end up related. diff -uprN linux-2.6.13/drivers/mtd/maps/Kconfig linux-plat-flash/drivers/mtd/maps/Kconfig --- linux-2.6.13/drivers/mtd/maps/Kconfig 2005-08-29 00:41:01.000000000 +0100 +++ linux-plat-flash/drivers/mtd/maps/Kconfig 2005-09-08 18:51:13.984319480 +0100 @@ -624,5 +624,12 @@ config MTD_PLATRAM This selection automatically selects the map_ram driver. +config MTD_PLATFLASH + tristate "Map driver for platform device physically mapped flash" + depends on MTD + help + Map driver allowing MTD devices which are physically mapped into + the CPU's address space to be enumerated using the platform bus. + endmenu diff -uprN linux-2.6.13/drivers/mtd/maps/Makefile linux-plat-flash/drivers/mtd/maps/Makefile --- linux-2.6.13/drivers/mtd/maps/Makefile 2005-08-29 00:41:01.000000000 +0100 +++ linux-plat-flash/drivers/mtd/maps/Makefile 2005-09-08 18:51:08.706121888 +0100 @@ -69,4 +69,5 @@ obj-$(CONFIG_MTD_WRSBC8260) += wr_sbc82x obj-$(CONFIG_MTD_DMV182) += dmv182.o obj-$(CONFIG_MTD_SHARP_SL) += sharpsl-flash.o obj-$(CONFIG_MTD_PLATRAM) += plat-ram.o +obj-$(CONFIG_MTD_PLATFLASH) += plat-flash.o obj-$(CONFIG_MTD_OMAP_NOR) += omap_nor.o diff -uprN linux-2.6.13/drivers/mtd/maps/plat-flash.c linux-plat-flash/drivers/mtd/maps/plat-flash.c --- linux-2.6.13/drivers/mtd/maps/plat-flash.c 1970-01-01 01:00:00.000000000 +0100 +++ linux-plat-flash/drivers/mtd/maps/plat-flash.c 2005-09-08 18:48:56.711188168 +0100 @@ -0,0 +1,270 @@ +/* drivers/mtd/maps/plat-flash.c + * + * (c) 2004-2005 Simtec Electronics + * http://www.simtec.co.uk/products/SWLINUX/ + * Ben Dooks + * + * Generic platform device based flash mappings. + * + * $Id: $ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include + +/* private structure for each mtd platform ram device created */ + +struct platflash_info { + struct device *dev; + struct mtd_info *mtd; + struct map_info map; + struct mtd_partition *partitions; + struct resource *area; +}; + +/* to_platflash_info() + * + * device private data to struct platflash_info conversion +*/ + +static inline struct platflash_info *to_platflash_info(struct device *dev) +{ + return (struct platflash_info *)dev_get_drvdata(dev); +} + +/* platflash_remove + * + * called to remove the device from the driver's control +*/ + +static int platflash_remove(struct device *dev) +{ + struct platflash_info *info = to_platflash_info(dev); + + dev_set_drvdata(dev, NULL); + + dev_dbg(dev, "removing device\n"); + + if (info == NULL) + return 0; + + if (info->mtd) { +#ifdef CONFIG_MTD_PARTITIONS + if (info->partitions) { + del_mtd_partitions(info->mtd); + kfree(info->partitions); + } +#endif + del_mtd_device(info->mtd); + map_destroy(info->mtd); + } + + /* release resources */ + + if (info->area) { + release_resource(info->area); + kfree(info->area); + } + + if (info->map.virt != NULL) + iounmap(info->map.virt); + + kfree(info); + + return 0; +} + +/* platflash_probe + * + * called from device drive system when a device matching our + * driver is found. +*/ + +static int platflash_probe(struct device *dev) +{ + struct platform_device *pd = to_platform_device(dev); + struct platflash_info *info; + struct platdata_mtd_flash *pdata; + struct resource *res; + int err = 0; + int i; + + dev_dbg(dev, "probe entered\n"); + + if (dev->platform_data == NULL) { + dev_err(dev, "no platform data supplied\n"); + err = -ENOENT; + goto exit_error; + } + + pdata = dev->platform_data; + + if (pdata->chip_probes == 0) { + dev_err(dev, "no chip probes specified\n"); + err = -ENOENT; + goto exit_error; + } + + info = kmalloc(sizeof(*info), GFP_KERNEL); + if (info == NULL) { + dev_err(dev, "no memory for flash info\n"); + err = -ENOMEM; + goto exit_error; + } + + memset(info, 0, sizeof(*info)); + dev_set_drvdata(dev, info); + + info->dev = dev; + + /* get the resource for the memory mapping */ + + res = platform_get_resource(pd, IORESOURCE_MEM, 0); + + if (res == NULL) { + dev_err(dev, "no memory resource specified\n"); + err = -ENOENT; + goto exit_free; + } + + dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start); + + /* setup map parameters */ + + info->map.phys = res->start; + info->map.size = (res->end - res->start) + 1; + info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->name; + info->map.bankwidth = pdata->bankwidth; + + /* register our usage of the memory area */ + + info->area = request_mem_region(res->start, info->map.size, pd->name); + if (info->area == NULL) { + dev_err(dev, "failed to request memory region\n"); + err = -EIO; + goto exit_free; + } + + /* remap the memory area */ + + info->map.virt = ioremap(res->start, info->map.size); + dev_dbg(dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); + + if (info->map.virt == NULL) { + dev_err(dev, "failed to ioremap() region\n"); + err = -EIO; + goto exit_free; + } + + simple_map_init(&info->map); + + dev_dbg(dev, "initialised map, probing for mtd\n"); + + /* probe for the right mtd map driver */ + i = 0; + while (pdata->chip_probes[i]) { + dev_dbg(dev, "probing with %s\n", pdata->chip_probes[i]); + info->mtd = do_map_probe(pdata->chip_probes[i], &info->map); + i++; + if (info->mtd != NULL) + break; + } + if (info->mtd == NULL) { + dev_err(dev, "failed to identify device\n"); + err = -ENOMEM; + goto exit_free; + } + + info->mtd->owner = THIS_MODULE; + + /* check to see if there are any available partitions, or wether + * to add this device whole */ + +#ifdef CONFIG_MTD_PARTITIONS + if (pdata->nr_partitions > 0) { + if (pdata->partition_probes) + { + err = parse_mtd_partitions(info->mtd, + pdata->partition_probes, + &info->partitions, 0); + } + else + { + err = pdata->nr_partitions; + info->partitions = pdata->partitions; + } + + if (err > 0) { + err = add_mtd_partitions(info->mtd, info->partitions, + err); + } + } +#endif /* CONFIG_MTD_PARTITIONS */ + + if (add_mtd_device(info->mtd)) { + dev_err(dev, "add_mtd_device() failed\n"); + err = -ENOMEM; + } + + dev_info(dev, "registered mtd device\n"); + return err; + + exit_free: + platflash_remove(dev); + exit_error: + return err; +} + +/* device driver info */ + +static struct device_driver platflash_driver = { + .name = "mtd-phys", + .bus = &platform_bus_type, + .probe = platflash_probe, + .remove = platflash_remove, +}; + +/* module init/exit */ + +static int __init platflash_init(void) +{ + return driver_register(&platflash_driver); +} + +static void __exit platflash_exit(void) +{ + driver_unregister(&platflash_driver); +} + +module_init(platflash_init); +module_exit(platflash_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mark Brown "); +MODULE_DESCRIPTION("MTD platform map driver"); diff -uprN linux-2.6.13/include/linux/mtd/plat-flash.h linux-plat-flash/include/linux/mtd/plat-flash.h --- linux-2.6.13/include/linux/mtd/plat-flash.h 1970-01-01 01:00:00.000000000 +0100 +++ linux-plat-flash/include/linux/mtd/plat-flash.h 2005-09-08 18:49:28.000000000 +0100 @@ -0,0 +1,29 @@ +/* linux/include/mtd/plat-flash.h + * + * (c) 2004 Simtec Electronics + * http://www.simtec.co.uk/products/SWLINUX/ + * Ben Dooks + * + * Generic platform device based flash map + * + * $Id: $ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#ifndef __LINUX_MTD_PLATFLASH_H +#define __LINUX_MTD_PLATFLASH_H __FILE__ + +struct platdata_mtd_flash { + char *mapname; + char **chip_probes; + char **partition_probes; + struct mtd_partition *partitions; + int nr_partitions; + int bankwidth; +}; + +#endif /* __LINUX_MTD_PLATRAM_H */ -- "You grabbed my hand and we fell into it, like a daydream - or a fever."