--- /dev/null
+/*
+ * Flash mappings described by the OF (or flattened) device tree
+ *
+ * Copyright (C) 2006 MontaVista Software Inc.
+ * Author: Vitaly Wool <vwool@ru.mvista.com>
+ *
+ * Revised to handle newer style flash binding by:
+ * Copyright (C) 2007 David Gibson, IBM Corporation.
+ *
+ * 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/device.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/concat.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+struct of_flash_list {
+ struct mtd_info *mtd;
+ struct map_info map;
+ struct resource *res;
+};
+
+struct of_flash {
+ struct mtd_info *cmtd;
+ int list_size; /* number of elements in of_flash_list */
+ struct of_flash_list list[0];
+};
+
+static int of_flash_remove(struct platform_device *dev)
+{
+ struct of_flash *info;
+ int i;
+
+ info = dev_get_drvdata(&dev->dev);
+ if (!info)
+ return 0;
+ dev_set_drvdata(&dev->dev, NULL);
+
+ if (info->cmtd) {
+ mtd_device_unregister(info->cmtd);
+ if (info->cmtd != info->list[0].mtd)
+ mtd_concat_destroy(info->cmtd);
+ }
+
+ for (i = 0; i < info->list_size; i++) {
+ if (info->list[i].mtd)
+ map_destroy(info->list[i].mtd);
+
+ if (info->list[i].map.virt)
+ iounmap(info->list[i].map.virt);
+
+ if (info->list[i].res) {
+ release_resource(info->list[i].res);
+ kfree(info->list[i].res);
+ }
+ }
+ return 0;
+}
+
+static const char * const rom_probe_types[] = {
+ "cfi_probe", "jedec_probe", "map_rom" };
+
+/* Helper function to handle probing of the obsolete "direct-mapped"
+ * compatible binding, which has an extra "probe-type" property
+ * describing the type of flash probe necessary. */
+static struct mtd_info *obsolete_probe(struct platform_device *dev,
+ struct map_info *map)
+{
+ struct device_node *dp = dev->dev.of_node;
+ const char *of_probe;
+ struct mtd_info *mtd;
+ int i;
+
+ dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
+ "flash binding\n");
+
+ of_probe = of_get_property(dp, "probe-type", NULL);
+ if (!of_probe) {
+ for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
+ mtd = do_map_probe(rom_probe_types[i], map);
+ if (mtd)
+ return mtd;
+ }
+ return NULL;
+ } else if (strcmp(of_probe, "CFI") == 0) {
+ return do_map_probe("cfi_probe", map);
+ } else if (strcmp(of_probe, "JEDEC") == 0) {
+ return do_map_probe("jedec_probe", map);
+ } else {
+ if (strcmp(of_probe, "ROM") != 0)
+ dev_warn(&dev->dev, "obsolete_probe: don't know probe "
+ "type '%s', mapping as rom\n", of_probe);
+ return do_map_probe("map_rom", map);
+ }
+}
+
+/* When partitions are set we look for a linux,part-probe property which
+ specifies the list of partition probers to use. If none is given then the
+ default is use. These take precedence over other device tree
+ information. */
+static const char * const part_probe_types_def[] = {
+ "cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
+
+static const char * const *of_get_probes(struct device_node *dp)
+{
+ const char *cp;
+ int cplen;
+ unsigned int l;
+ unsigned int count;
+ const char **res;
+
+ cp = of_get_property(dp, "linux,part-probe", &cplen);
+ if (cp == NULL)
+ return part_probe_types_def;
+
+ count = 0;
+ for (l = 0; l != cplen; l++)
+ if (cp[l] == 0)
+ count++;
+
+ res = kzalloc((count + 1)*sizeof(*res), GFP_KERNEL);
+ count = 0;
+ while (cplen > 0) {
+ res[count] = cp;
+ l = strlen(cp) + 1;
+ cp += l;
+ cplen -= l;
+ count++;
+ }
+ return res;
+}
+
+static void of_free_probes(const char * const *probes)
+{
+ if (probes != part_probe_types_def)
+ kfree(probes);
+}
+
+static struct of_device_id of_flash_match[];
+static int of_flash_probe(struct platform_device *dev)
+{
+ const char * const *part_probe_types;
+ const struct of_device_id *match;
+ struct device_node *dp = dev->dev.of_node;
+ struct resource res;
+ struct of_flash *info;
+ const char *probe_type;
+ const __be32 *width;
+ int err;
+ int i;
+ int count;
+ const __be32 *p;
+ int reg_tuple_size;
+ struct mtd_info **mtd_list = NULL;
+ resource_size_t res_size;
+ struct mtd_part_parser_data ppdata;
+ bool map_indirect;
+ const char *mtd_name = NULL;
+
+ match = of_match_device(of_flash_match, &dev->dev);
+ if (!match)
+ return -EINVAL;
+ probe_type = match->data;
+
+ reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
+
+ of_property_read_string(dp, "linux,mtd-name", &mtd_name);
+
+ /*
+ * Get number of "reg" tuples. Scan for MTD devices on area's
+ * described by each "reg" region. This makes it possible (including
+ * the concat support) to support the Intel P30 48F4400 chips which
+ * consists internally of 2 non-identical NOR chips on one die.
+ */
+ p = of_get_property(dp, "reg", &count);
+ if (count % reg_tuple_size != 0) {
+ dev_err(&dev->dev, "Malformed reg property on %s\n",
+ dev->dev.of_node->full_name);
+ err = -EINVAL;
+ goto err_flash_remove;
+ }
+ count /= reg_tuple_size;
+
+ map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
+
+ err = -ENOMEM;
+ info = devm_kzalloc(&dev->dev,
+ sizeof(struct of_flash) +
+ sizeof(struct of_flash_list) * count, GFP_KERNEL);
+ if (!info)
+ goto err_flash_remove;
+
+ dev_set_drvdata(&dev->dev, info);
+
+ mtd_list = kzalloc(sizeof(*mtd_list) * count, GFP_KERNEL);
+ if (!mtd_list)
+ goto err_flash_remove;
+
+ for (i = 0; i < count; i++) {
+ err = -ENXIO;
+ if (of_address_to_resource(dp, i, &res)) {
+ /*
+ * Continue with next register tuple if this
+ * one is not mappable
+ */
+ continue;
+ }
+
+ dev_dbg(&dev->dev, "of_flash device: %pR\n", &res);
+
+ err = -EBUSY;
+ res_size = resource_size(&res);
+ info->list[i].res = request_mem_region(res.start, res_size,
+ dev_name(&dev->dev));
+ if (!info->list[i].res)
+ goto err_out;
+
+ err = -ENXIO;
+ width = of_get_property(dp, "bank-width", NULL);
+ if (!width) {
+ dev_err(&dev->dev, "Can't get bank width from device"
+ " tree\n");
+ goto err_out;
+ }
+
+ info->list[i].map.name = mtd_name ?: dev_name(&dev->dev);
+ info->list[i].map.phys = res.start;
+ info->list[i].map.size = res_size;
+ info->list[i].map.bankwidth = be32_to_cpup(width);
+ info->list[i].map.device_node = dp;
+
+ err = -ENOMEM;
+ info->list[i].map.virt = ioremap(info->list[i].map.phys,
+ info->list[i].map.size);
+ if (!info->list[i].map.virt) {
+ dev_err(&dev->dev, "Failed to ioremap() flash"
+ " region\n");
+ goto err_out;
+ }
+
+ simple_map_init(&info->list[i].map);
+
+ /*
+ * On some platforms (e.g. MPC5200) a direct 1:1 mapping
+ * may cause problems with JFFS2 usage, as the local bus (LPB)
+ * doesn't support unaligned accesses as implemented in the
+ * JFFS2 code via memcpy(). By setting NO_XIP, the
+ * flash will not be exposed directly to the MTD users
+ * (e.g. JFFS2) any more.
+ */
+ if (map_indirect)
+ info->list[i].map.phys = NO_XIP;
+
+ if (probe_type) {
+ info->list[i].mtd = do_map_probe(probe_type,
+ &info->list[i].map);
+ } else {
+ info->list[i].mtd = obsolete_probe(dev,
+ &info->list[i].map);
+ }
+
+ /* Fall back to mapping region as ROM */
+ if (!info->list[i].mtd) {
+ dev_warn(&dev->dev,
+ "do_map_probe() failed for type %s\n",
+ probe_type);
+
+ info->list[i].mtd = do_map_probe("map_rom",
+ &info->list[i].map);
+ }
+ mtd_list[i] = info->list[i].mtd;
+
+ err = -ENXIO;
+ if (!info->list[i].mtd) {
+ dev_err(&dev->dev, "do_map_probe() failed\n");
+ goto err_out;
+ } else {
+ info->list_size++;
+ }
+ info->list[i].mtd->owner = THIS_MODULE;
+ info->list[i].mtd->dev.parent = &dev->dev;
+ }
+
+ err = 0;
+ info->cmtd = NULL;
+ if (info->list_size == 1) {
+ info->cmtd = info->list[0].mtd;
+ } else if (info->list_size > 1) {
+ /*
+ * We detected multiple devices. Concatenate them together.
+ */
+ info->cmtd = mtd_concat_create(mtd_list, info->list_size,
+ dev_name(&dev->dev));
+ }
+ if (info->cmtd == NULL)
+ err = -ENXIO;
+
+ if (err)
+ goto err_out;
+
+ ppdata.of_node = dp;
+ part_probe_types = of_get_probes(dp);
+ mtd_device_parse_register(info->cmtd, part_probe_types, &ppdata,
+ NULL, 0);
+ of_free_probes(part_probe_types);
+
+ kfree(mtd_list);
+
+ return 0;
+
+err_out:
+ kfree(mtd_list);
+err_flash_remove:
+ of_flash_remove(dev);
+
+ return err;
+}
+
+static struct of_device_id of_flash_match[] = {
+ {
+ .compatible = "cfi-flash",
+ .data = (void *)"cfi_probe",
+ },
+ {
+ /* FIXME: JEDEC chips can't be safely and reliably
+ * probed, although the mtd code gets it right in
+ * practice most of the time. We should use the
+ * vendor and device ids specified by the binding to
+ * bypass the heuristic probe code, but the mtd layer
+ * provides, at present, no interface for doing so
+ * :(. */
+ .compatible = "jedec-flash",
+ .data = (void *)"jedec_probe",
+ },
+ {
+ .compatible = "mtd-ram",
+ .data = (void *)"map_ram",
+ },
+ {
+ .compatible = "mtd-rom",
+ .data = (void *)"map_rom",
+ },
+ {
+ .type = "rom",
+ .compatible = "direct-mapped"
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, of_flash_match);
+
+static struct platform_driver of_flash_driver = {
+ .driver = {
+ .name = "of-flash",
+ .of_match_table = of_flash_match,
+ },
+ .probe = of_flash_probe,
+ .remove = of_flash_remove,
+};
+
+module_platform_driver(of_flash_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
+MODULE_DESCRIPTION("Device tree based MTD map driver");
Code Review / kvmfornfv.git / blobdiff