1 files changed, 372 insertions, 0 deletions
diff --git a/drivers/mtd/maps/physmap_acpi.c b/drivers/mtd/maps/physmap_acpi.c
new file mode 100644
index 000000000000..f425dfd27a7a
--- /dev/null
+++ b/drivers/mtd/maps/physmap_acpi.c
@@ -0,0 +1,372 @@
+/*
+ * Flash mappings described by the ACPI
+ *
+ * Copyright (C) 2006 MontaVista Software Inc.
+ * Author: Vitaly Wool <vwool@ru.mvista.com>
+ * Copyright (C) 2007 David Gibson, IBM Corporation.
+ *
+ * Revised to handle ACPI style flash binding by:
+ *   Copyright (C) 2013 Tomasz Nowicki <tomasz.nowicki@linaro.org>
+ *
+ * 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.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/acpi.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+struct acpi_flash_list {
+	struct mtd_info *mtd;
+	struct map_info map;
+	struct resource *res;
+};
+
+struct acpi_flash {
+	struct mtd_info		*cmtd;
+	int list_size; /* number of elements in acpi_flash_list */
+	struct acpi_flash_list	list[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 acpi_dsm_entry entry;
+	struct mtd_info *mtd;
+	acpi_handle handler;
+	char *acpi_probe;
+	int i, err, len;
+
+	handler = ACPI_HANDLE(&dev->dev);
+	dev_warn(&dev->dev, "ACPI uses obsolete \"direct-mapped\" flash "
+		 "binding\n");
+
+	err = acpi_dsm_lookup_value(handler, "probe-type", 0, &entry);
+	if (err || entry.value == NULL) {
+		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;
+	}
+
+	len = strlen(entry.value) + 1;
+	acpi_probe = devm_kzalloc(&dev->dev, len, GFP_KERNEL);
+	strncpy(acpi_probe, entry.value, len);
+	kfree(entry.key);
+	kfree(entry.value);
+
+	if (strcmp(acpi_probe, "CFI") == 0) {
+		return do_map_probe("cfi_probe", map);
+	} else if (strcmp(acpi_probe, "JEDEC") == 0) {
+		return do_map_probe("jedec_probe", map);
+	} else {
+		if (strcmp(acpi_probe, "ROM") != 0)
+			dev_warn(&dev->dev, "obsolete_probe: don't know probe "
+				 "type '%s', mapping as rom\n", acpi_probe);
+		return do_map_probe("mtd_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", NULL };
+
+static const char * const *acpi_get_part_probes(struct device *dev)
+{
+	struct acpi_dsm_entry entry;
+	const char **res;
+	int cplen, err, len;
+	unsigned int count = 0, i;
+	char *cp = NULL;
+
+	acpi_handle handler = ACPI_HANDLE(dev);
+
+	/* Get space separated strings */
+	err = acpi_dsm_lookup_value(handler, "linux,part-probe", 0, &entry);
+	if (err || entry.value == NULL)
+			return part_probe_types_def;
+
+	len = strlen(entry.value) + 1;
+	cp = devm_kzalloc(dev, len, GFP_KERNEL);
+	strncpy(cp, entry.value, len);
+	kfree(entry.key);
+	kfree(entry.value);
+
+	cplen = strlen(cp);
+	for (i = 0; i != cplen; i++)
+		if (cp[i] == ' ')
+			count++;
+
+	/* Create the table with references to strings */
+	res = kzalloc((count + 1) * sizeof(char *), GFP_KERNEL);
+	for (i = 0; i < count + 1; i++) {
+		res[i] = cp;
+		cp = strnchr(cp, cplen, ' ');
+		if (cp == NULL)
+			break;
+
+		*cp++ = '\0';
+		cplen = strlen(cp);
+	}
+	return res;
+}
+
+static void acpi_free_probes(const char * const *probes)
+{
+	if (probes != part_probe_types_def)
+		kfree(probes);
+}
+
+static const struct acpi_device_id acpi_flash_match[];
+static int acpi_flash_remove(struct platform_device *dev);
+
+static int acpi_flash_probe(struct platform_device *dev)
+{
+	const char * const *part_probe_types;
+	const struct acpi_device_id *id;
+	resource_size_t res_size;
+	struct acpi_flash *info;
+	const char *probe_type;
+	struct resource *res;
+	acpi_handle handler;
+	int err = 0, i;
+	int bank_width = 0, map_indirect = 0;
+	struct mtd_info **mtd_list = NULL;
+	char *mtd_name = NULL;
+	int len, count = 0;
+	struct acpi_dsm_entry entry;
+
+	handler = ACPI_HANDLE(&dev->dev);
+
+	id = acpi_match_device(acpi_flash_match, &dev->dev);
+	if (!id)
+		return -ENODEV;
+
+	probe_type = (const char *)id->driver_data;
+
+	err = acpi_dsm_lookup_value(handler, "linux,mtd-name", 0, &entry);
+	if (err == 0 && entry.value) {
+		len = strlen(entry.value) + 1;
+		mtd_name = devm_kzalloc(&dev->dev, len, GFP_KERNEL);
+		strncpy(mtd_name, entry.value, len);
+		kfree(entry.key);
+		kfree(entry.value);
+	}
+
+	err = acpi_dsm_lookup_value(handler, "no-unaligned-direct-access",
+				0, &entry);
+	if (err == 0 && kstrtoint(entry.value, 0, &map_indirect) == 0) {
+		kfree(entry.key);
+		kfree(entry.value);
+	}
+
+	while (platform_get_resource(dev, IORESOURCE_MEM, count))
+		count++;
+
+	if (!count) {
+		dev_err(&dev->dev, "No resources found for %s device\n",
+				dev_name(&dev->dev));
+		err = -ENXIO;
+		goto err_flash_remove;
+	}
+
+	info = devm_kzalloc(&dev->dev,
+			    sizeof(struct acpi_flash) +
+			    sizeof(struct acpi_flash_list) * count, GFP_KERNEL);
+	if (!info) {
+		err = -ENOMEM;
+		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++) {
+		res = platform_get_resource(dev, IORESOURCE_MEM, i);
+		dev_dbg(&dev->dev, "resource[%d]: address 0x%lx size 0x%lx\n",
+			i, (long)res->start, (long)resource_size(res));
+
+		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) {
+			err = -EBUSY;
+			goto err_out;
+		}
+
+		/* Mandatory property */
+		err = acpi_dsm_lookup_value(handler, "bank-width", 0, &entry);
+		if (err || kstrtoint(entry.value, 0, &bank_width) != 0) {
+			dev_err(&dev->dev,
+				"Can't get bank width from DSDT\n");
+			goto err_out;
+		}
+		kfree(entry.key);
+		kfree(entry.value);
+
+		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 = bank_width;
+		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");
+			err = -ENOMEM;
+			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);
+		}
+
+		if (!info->list[i].mtd) {
+			dev_err(&dev->dev, "do_map_probe() failed\n");
+			err = -ENXIO;
+			goto err_out;
+		} else
+			info->list_size++;
+
+		info->list[i].mtd->owner = THIS_MODULE;
+		info->list[i].mtd->dev.parent = &dev->dev;
+		mtd_list[i] = info->list[i].mtd;
+	}
+
+	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;
+		goto err_out;
+	}
+
+	part_probe_types = acpi_get_part_probes(&dev->dev);
+	mtd_device_parse_register(info->cmtd, part_probe_types, NULL,
+			NULL, 0);
+	acpi_free_probes(part_probe_types);
+
+	kfree(mtd_list);
+
+	return 0;
+
+err_out:
+	kfree(mtd_list);
+err_flash_remove:
+	acpi_flash_remove(dev);
+
+	return err;
+}
+
+static int acpi_flash_remove(struct platform_device *dev)
+{
+	struct acpi_flash *info;
+	int i;
+
+	info = dev_get_drvdata(&dev->dev);
+	if (!info)
+		return 0;
+	dev_set_drvdata(&dev->dev, NULL);
+
+	if (info->cmtd != info->list[0].mtd) {
+		mtd_device_unregister(info->cmtd);
+		mtd_concat_destroy(info->cmtd);
+	}
+
+	if (info->cmtd)
+		mtd_device_unregister(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 struct acpi_device_id acpi_flash_match[] = {
+	{ "LNRO0015", (unsigned long)"cfi_probe"},
+	{ "LNRO0016", (unsigned long)"jedec_probe"},
+	{ "LNRO0017", (unsigned long)"map_ram"},
+	{ "LNRO0018", (unsigned long)"direct-mapped"},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, acpi_flash_match);
+
+static struct platform_driver acpi_flash_driver = {
+	.driver = {
+		.name = "acpi-flash",
+		.owner = THIS_MODULE,
+		.acpi_match_table = ACPI_PTR(acpi_flash_match),
+	},
+	.probe		= acpi_flash_probe,
+	.remove		= acpi_flash_remove,
+};
+
+module_platform_driver(acpi_flash_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tomasz Nowicki <tomasz.nowicki@linaro.org>");
+MODULE_DESCRIPTION("ACPI based MTD map driver");