Vitaly Wool wrote:
> Hi folks,
>
> inlined below is the patch that adds support for OF physmap descriptions. It was inspired by Sergey Shtylyov's patch to powerpc tree which can be found at
> http://patchwork.ozlabs.org/linuxppc/patch?id=6526 and uses the same description but implements a bit different concept. I. e. it doesn't try to pretend a platform device and use existing physmap driver but adds corresponding configurable physmap driver instead.
>
> drivers/mtd/maps/Kconfig | 9 +
> drivers/mtd/maps/Makefile | 1
> drivers/mtd/maps/physmap_of.c | 244 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 254 insertions(+)
>
> Signed-off-by: Vitaly Wool <vwool at ru.mvista.com>
>
> Index: linux-2.6.18/drivers/mtd/maps/physmap_of.c
> ===================================================================
> --- /dev/null
> +++ linux-2.6.18/drivers/mtd/maps/physmap_of.c
> @@ -0,0 +1,244 @@
> +/*
> + * Normal mappings of chips in physical memory for OF devices
> + *
> + * Copyright (C) 2006 MontaVista Software Inc.
> + * Author: Vitaly Wool <vwool at ru.mvista.com>
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/device.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/map.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/mtd/physmap.h>
> +#include <asm/io.h>
> +#include <asm/prom.h>
> +#include <asm/of_device.h>
> +
> +struct physmap_flash_info {
> + struct mtd_info *mtd;
> + struct map_info map;
> + struct resource *res;
> +#ifdef CONFIG_MTD_PARTITIONS
> + int nr_parts;
> + struct mtd_partition *parts;
> +#endif
> +};
> +
> +static const char *rom_probe_types[] = { "cfi_probe", "jedec_probe", "map_rom", NULL };
Well, these also could be passed in the node property.
> +#ifdef CONFIG_MTD_PARTITIONS
> +static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
Not really sure if RedBoot is relevant in this case.
> +#endif
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> +static int parse_flash_partitions(struct device_node *node,
> + struct mtd_partition **parts)
> +{
> + int i, plen, nr_parts = 0;
> + const u32 *part;
> + const char *name;
> +
> + part = get_property(node, "partitions", &plen);
> + if (part == NULL)
> + goto err;
> +
> + nr_parts = plen / (2 * sizeof(u32));
> + *parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
> + if (*parts == NULL) {
> + printk(KERN_ERR "Can't allocate the flash partition data!\n");
> + nr_parts = 0;
> + goto err;
> + }
> +
> + name = get_property(node, "partition-names", &plen);
> +
> + for (i = 0; i < nr_parts; i++) {
> + (*parts)[i].offset = *part++;
> + (*parts)[i].size = *part & ~1;
> + if (*part++ & 1) /* bit 0 set signifies read only partition */
> + (*parts)[i].mask_flags = MTD_WRITEABLE;
> +
> + if (name != NULL && plen > 0) {
> + int len = strlen(name) + 1;
> +
> + (*parts)[i].name = (char *)name;
> + plen -= len;
> + name += len;
> + } else
> + (*parts)[i].name = "unnamed";
> + }
> +err:
> + return nr_parts;
> +}
> +#endif
Well, it's not quite correct to confine the partition parsing to only
physmap driver, since it didn't pertain to only direct-mapped MTD by design.
However, I've run into some troubles trying to fit that into the standard MTD
paritition parser framework. May still be worth putting it into a separate
module, though...
[...]
> +static int __devinit of_physmap_probe(struct of_device *dev, const struct of_device_id *match)
> +{
> + struct device_node *dp = dev->node;
> + struct resource res;
> + struct physmap_flash_info *info;
> + const char **probe_type;
> + const u32 *width;
> + int err;
> +
> +
> + if (of_address_to_resource(dp, 0, &res)) {
> + dev_err(&dev->dev, "Can't get the flash mapping!\n");
> + err = -EINVAL;
> + goto err_out;
> + }
> +
> + dev_dbg(&dev->dev, "physmap flash device: %.8llx at %.8llx\n",
> + (unsigned long long)res.end - res.start + 1,
> + (unsigned long long)res.start);
> +
> + info = kzalloc(sizeof(struct physmap_flash_info), GFP_KERNEL);
> + if (info == NULL) {
> + err = -ENOMEM;
> + goto err_out;
> + }
> + memset(info, 0, sizeof(*info));
> +
> + dev_set_drvdata(&dev->dev, up);
> +
> + info->res = request_mem_region(res.start, res.end - res.start + 1,
> + dev->dev.bus_id);
Could also have just called request_resource(), incluing res into struct
physmap_flash_info, I think...
> + if (info->res == NULL) {
> + dev_err(&dev->dev, "Could not reserve memory region\n");
> + err = -ENOMEM;
> + goto err_out;
> + }
> +
> + width = get_property(dp, "bank-width", NULL);
> + if (width == NULL) {
> + dev_err(&dev->dev, "Can't get the flash bank width!\n");
> + err = -EINVAL;
> + goto err_out;
> + }
> +
> + info->map.name = dev->dev.bus_id;
> + info->map.phys = res.start;
> + info->map.size = res.end - res.start + 1;
> + info->map.bankwidth = *width;
> +
> + info->map.virt = ioremap(info->map.phys, info->map.size);
> + if (info->map.virt == NULL) {
> + dev_err(&dev->dev, "Failed to ioremap flash region\n");
> + err = EIO;
> + goto err_out;
> + }
> +
> + simple_map_init(&info->map);
> +
> + probe_type = rom_probe_types;
> + for (; info->mtd == NULL && *probe_type != NULL; probe_type++)
> + info->mtd = do_map_probe(*probe_type, &info->map);
> + if (info->mtd == NULL) {
> + dev_err(&dev->dev, "map_probe failed\n");
> + err = -ENXIO;
> + goto err_out;
> + }
> + info->mtd->owner = THIS_MODULE;
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> + err = parse_mtd_partitions(info->mtd, part_probe_types, &info->parts, 0);
> + if (err > 0) {
> + add_mtd_partitions(info->mtd, info->parts, err);
> + } else if ((err = parse_flash_partitions(dp, &info->parts)) > 0) {
> + dev_info(&dev->dev, "Using OF partition information\n");
> + add_mtd_partitions(info->mtd, info->parts, err);
> + info->nr_parts = err;
> + } else
> +#endif
> +
> + add_mtd_device(info->mtd);
> + return 0;
> +
> +err_out:
> + of_physmap_remove(dev);
> + return err;
> +
> + return 0;
> +
> +
> +}
> +
> +static struct of_device_id of_physmap_match[] = {
> + {
> + .name = "flash",
There's really no need to enforce the fixed name, when there's
"device_type" property defined. Instead it should be:
.device_name = "rom"
> + .compatible = "physmap"
Well, "direct-mapped" might have been a better choice...
> + },
> + { },
> +};
> +
> +MODULE_DEVICE_TABLE(of, of_physmap_match);
Erm, why this is needed?
WBR, Sergei