[PATCH/RFC] physmap for OF devices
Vitaly Wool
vwool at ru.mvista.com
Thu Nov 2 06:08:47 EST 2006
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 };
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
+#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
+
+static int of_physmap_remove(struct of_device *dev)
+{
+ struct physmap_flash_info *info;
+
+ info = dev_get_drvdata(&dev->dev);
+ if (info == NULL)
+ return 0;
+ dev_set_drvdata(&dev->dev, NULL);
+
+ if (info->mtd != NULL) {
+#ifdef CONFIG_MTD_PARTITIONS
+ if (info->nr_parts) {
+ del_mtd_partitions(info->mtd);
+ kfree(info->parts);
+ } else if (info->parts) {
+ del_mtd_partitions(info->mtd);
+ } else {
+ del_mtd_device(info->mtd);
+ }
+#else
+ del_mtd_device(info->mtd);
+#endif
+ map_destroy(info->mtd);
+ }
+
+ if (info->map.virt != NULL)
+ iounmap(info->map.virt);
+
+ if (info->res != NULL) {
+ release_resource(info->res);
+ kfree(info->res);
+ }
+
+ return 0;
+}
+
+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);
+ 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",
+ .compatible = "physmap"
+ },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, of_physmap_match);
+
+
+static struct of_platform_driver of_physmap_flash_driver = {
+ .name = "physmap-flash",
+ .match_table = of_physmap_match,
+ .probe = of_physmap_probe,
+ .remove = of_physmap_remove,
+};
+
+static int __init of_physmap_init(void)
+{
+ return of_register_driver(&of_physmap_flash_driver);
+}
+
+static void __exit of_physmap_exit(void)
+{
+ of_unregister_driver(&of_physmap_flash_driver);
+}
+
+module_init(of_physmap_init);
+module_exit(of_physmap_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vitaly Wool <vwool at ru.mvista.com>");
+MODULE_DESCRIPTION("Configurable MTD map driver for OF");
Index: linux-2.6.18/drivers/mtd/maps/Kconfig
===================================================================
--- linux-2.6.18.orig/drivers/mtd/maps/Kconfig
+++ linux-2.6.18/drivers/mtd/maps/Kconfig
@@ -60,6 +60,15 @@ config MTD_PHYSMAP_BANKWIDTH
Ignore this option if you use run-time physmap configuration
(i.e., run-time calling physmap_configure()).
+config MTD_PHYSMAP_OF
+ tristate "Flash device in physical memory map based on OF descirption"
+ depends on PPC && (MTD_CFI || MTD_JEDECPROBE || MTD_ROM)
+ help
+ This provides a 'mapping' driver which allows the NOR Flash and
+ ROM driver code to communicate with chips which are mapped
+ physically into the CPU's memory. The mapping description here is
+ taken from OF device tree.
+
config MTD_SUN_UFLASH
tristate "Sun Microsystems userflash support"
depends on SPARC && MTD_CFI
Index: linux-2.6.18/drivers/mtd/maps/Makefile
===================================================================
--- linux-2.6.18.orig/drivers/mtd/maps/Makefile
+++ linux-2.6.18/drivers/mtd/maps/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_MTD_MBX860) += mbx860.o
obj-$(CONFIG_MTD_CEIVA) += ceiva.o
obj-$(CONFIG_MTD_OCTAGON) += octagon-5066.o
obj-$(CONFIG_MTD_PHYSMAP) += physmap.o
+obj-$(CONFIG_MTD_PHYSMAP_OF) += physmap_of.o
obj-$(CONFIG_MTD_PNC2000) += pnc2000.o
obj-$(CONFIG_MTD_PCMCIA) += pcmciamtd.o
obj-$(CONFIG_MTD_RPXLITE) += rpxlite.o
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