[PATCH 1/2] mtd: NOR flash driver for OMAP-L137/AM17x
Savinay Dharmappa
savinay.dharmappa at ti.com
Thu Oct 7 07:31:14 EDT 2010
From: David Griego <dgriego at mvista.com>
OMAP-L137/AM17x has limited number of dedicated EMIFA
address pins, enough to interface directly to an SDRAM.
If a device such as an asynchronous flash needs to be
attached to the EMIFA, then either GPIO pins or a chip
select may be used to control the flash device's upper
address lines.
This patch adds support for the NOR flash on the OMAP-L137/
AM17x user interface daughter board using the latch-addr-flash
MTD mapping driver which allows flashes to be partially
physically addressed. The upper address lines are set by
a board specific code which is a separate patch.
Signed-off-by: Aleksey Makarov <amakarov at ru.mvista.com>
Signed-off-by: Sergei Shtylyov <sshtylyov at ru.mvista.com>
Signed-off-by: Savinay Dharmappa <savinay.dharmappa at ti.com>
---
drivers/mtd/maps/Kconfig | 9 +
drivers/mtd/maps/Makefile | 1 +
drivers/mtd/maps/latch-addr-flash.c | 271 ++++++++++++++++++++++++++++++++++
include/linux/mtd/latch-addr-flash.h | 29 ++++
4 files changed, 310 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/maps/latch-addr-flash.c
create mode 100644 include/linux/mtd/latch-addr-flash.h
diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index 701d942..b794ea2 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -543,4 +543,13 @@ config MTD_PISMO
When built as a module, it will be called pismo.ko
+config MTD_LATCH_ADDR
+ tristate "Latch-assisted Flash Chip Support"
+ depends on MTD_COMPLEX_MAPPINGS
+ help
+ Map driver which allows flashes to be partially physically addressed
+ and have the upper address lines set by a board specific code.
+
+ If compiled as a module, it will be called latch-addr-flash.
+
endmenu
diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
index f216bb5..35c3573 100644
--- a/drivers/mtd/maps/Makefile
+++ b/drivers/mtd/maps/Makefile
@@ -58,3 +58,4 @@ obj-$(CONFIG_MTD_BFIN_ASYNC) += bfin-async-flash.o
obj-$(CONFIG_MTD_RBTX4939) += rbtx4939-flash.o
obj-$(CONFIG_MTD_VMU) += vmu-flash.o
obj-$(CONFIG_MTD_GPIO_ADDR) += gpio-addr-flash.o
+obj-$(CONFIG_MTD_LATCH_ADDR) += latch-addr-flash.o
diff --git a/drivers/mtd/maps/latch-addr-flash.c b/drivers/mtd/maps/latch-addr-flash.c
new file mode 100644
index 0000000..e3a7f91
--- /dev/null
+++ b/drivers/mtd/maps/latch-addr-flash.c
@@ -0,0 +1,271 @@
+/*
+ * Interface for NOR flash driver whose high address lines are latched
+ *
+ * Copyright 2000 Nicolas Pitre <nico at cam.org>
+ * Copyright 2005-2008 Analog Devices Inc.
+ * Coyright (C) 2008 MontaVista Software, Inc. <source at mvista.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+#include <linux/platform_device.h>
+#include <linux/mtd/latch-addr-flash.h>
+#include <linux/slab.h>
+
+#define DRIVER_NAME "latch-addr-flash"
+
+struct latch_addr_flash_info {
+ struct mtd_info *mtd;
+ struct map_info map;
+ struct resource *res;
+
+ void (*set_window)(unsigned long offset, void *data);
+ void *data;
+
+ /* cache; could be found out of res */
+ unsigned long win_mask;
+
+ int nr_parts;
+ struct mtd_partition *parts;
+
+ spinlock_t lock;
+};
+
+static map_word lf_read(struct map_info *map, unsigned long ofs)
+{
+ struct latch_addr_flash_info *info;
+ map_word datum;
+
+ info = (struct latch_addr_flash_info *)map->map_priv_1;
+
+ spin_lock(&info->lock);
+
+ info->set_window(ofs, info->data);
+ datum = inline_map_read(map, info->win_mask & ofs);
+
+ spin_unlock(&info->lock);
+
+ return datum;
+}
+
+static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
+{
+ struct latch_addr_flash_info *info;
+
+ info = (struct latch_addr_flash_info *)map->map_priv_1;
+
+ spin_lock(&info->lock);
+
+ info->set_window(ofs, info->data);
+ inline_map_write(map, datum, info->win_mask & ofs);
+
+ spin_unlock(&info->lock);
+}
+
+static void lf_copy_from(struct map_info *map, void *to,
+ unsigned long from, ssize_t len)
+{
+ struct latch_addr_flash_info *info =
+ (struct latch_addr_flash_info *) map->map_priv_1;
+ unsigned n;
+
+ while (len > 0) {
+ n = info->win_mask + 1 - (from & info->win_mask);
+ if (n > len)
+ n = len;
+
+ spin_lock(&info->lock);
+
+ info->set_window(from, info->data);
+ memcpy_fromio(to, map->virt + (from & info->win_mask), n);
+
+ spin_unlock(&info->lock);
+
+ to += n;
+ from += n;
+ len -= n;
+ }
+}
+
+static const char *rom_probe_types[] = { "cfi_probe", NULL };
+
+static const char *part_probe_types[] = { "cmdlinepart", NULL };
+
+static int latch_addr_flash_remove(struct platform_device *dev)
+{
+ struct latch_addr_flash_info *info;
+ struct latch_addr_flash_data *latch_addr_data;
+
+ info = platform_get_drvdata(dev);
+ if (info == NULL)
+ return 0;
+ platform_set_drvdata(dev, NULL);
+
+ latch_addr_data = dev->dev.platform_data;
+
+ if (info->mtd != NULL) {
+ if (mtd_has_partitions()) {
+ if (info->nr_parts) {
+ del_mtd_partitions(info->mtd);
+ kfree(info->parts);
+ } else if (latch_addr_data->nr_parts) {
+ del_mtd_partitions(info->mtd);
+ } else {
+ del_mtd_device(info->mtd);
+ }
+ } else {
+ del_mtd_device(info->mtd);
+ }
+ map_destroy(info->mtd);
+ }
+
+ if (info->map.virt != NULL)
+ iounmap(info->map.virt);
+
+ if (info->res != NULL)
+ release_mem_region(info->res->start, resource_size(info->res));
+
+ kfree(info);
+
+ if (latch_addr_data->done)
+ latch_addr_data->done(latch_addr_data->data);
+
+ return 0;
+}
+
+static int __devinit latch_addr_flash_probe(struct platform_device *dev)
+{
+ struct latch_addr_flash_data *latch_addr_data;
+ struct latch_addr_flash_info *info;
+ resource_size_t win_base = dev->resource->start;
+ resource_size_t win_size = resource_size(dev->resource);
+ const char **probe_type;
+ int chipsel;
+ int err;
+
+ latch_addr_data = dev->dev.platform_data;
+ if (latch_addr_data == NULL)
+ return -ENODEV;
+
+ pr_notice("latch-addr platform flash device: %#llx byte "
+ "window at %#.8llx\n",
+ (unsigned long long)win_size, (unsigned long long)win_base);
+
+ chipsel = dev->id;
+
+ if (latch_addr_data->init) {
+ err = latch_addr_data->init(latch_addr_data->data, chipsel);
+ if (err != 0)
+ return err;
+ }
+
+ info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
+ if (info == NULL) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ platform_set_drvdata(dev, info);
+
+ info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
+ if (info->res == NULL) {
+ dev_err(&dev->dev, "Could not reserve memory region\n");
+ err = -EBUSY;
+ goto free_info;
+ }
+
+ info->map.name = DRIVER_NAME;
+ info->map.size = latch_addr_data->size;
+ info->map.bankwidth = latch_addr_data->width;
+
+ info->map.phys = NO_XIP;
+ info->map.virt = ioremap(win_base, win_size);
+ if (!info->map.virt) {
+ err = -ENOMEM;
+ goto free_res;
+ }
+
+ info->map.map_priv_1 = (unsigned long)info;
+
+ info->map.read = lf_read;
+ info->map.copy_from = lf_copy_from;
+ info->map.write = lf_write;
+ info->set_window = latch_addr_data->set_window;
+ info->data = latch_addr_data->data;
+ info->win_mask = win_size - 1;
+
+ spin_lock_init(&info->lock);
+
+ for (probe_type = rom_probe_types; !info->mtd && *probe_type;
+ probe_type++)
+ info->mtd = do_map_probe(*probe_type, &info->map);
+
+ if (info->mtd == NULL) {
+ dev_err(&dev->dev, "map_probe failed\n");
+ err = -ENODEV;
+ goto iounmap;
+ }
+ info->mtd->owner = THIS_MODULE;
+
+ if (mtd_has_partitions()) {
+
+ err = parse_mtd_partitions(info->mtd, part_probe_types,
+ &info->parts, 0);
+ if (err > 0) {
+ add_mtd_partitions(info->mtd, info->parts, err);
+ return 0;
+ }
+ if (latch_addr_data->nr_parts) {
+ pr_notice("Using latch-addr-flash partition information\n");
+ add_mtd_partitions(info->mtd, latch_addr_data->parts,
+ latch_addr_data->nr_parts);
+ return 0;
+ }
+ }
+ add_mtd_device(info->mtd);
+ return 0;
+
+iounmap:
+ iounmap(info->map.virt);
+free_res:
+ release_mem_region(info->res->start, resource_size(info->res));
+free_info:
+ kfree(info);
+done:
+ if (latch_addr_data->done)
+ latch_addr_data->done(latch_addr_data->data);
+ return err;
+}
+
+static struct platform_driver latch_addr_flash_driver = {
+ .probe = latch_addr_flash_probe,
+ .remove = __devexit_p(latch_addr_flash_remove),
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+};
+
+static int __init latch_addr_flash_init(void)
+{
+ return platform_driver_register(&latch_addr_flash_driver);
+}
+module_init(latch_addr_flash_init);
+
+static void __exit latch_addr_flash_exit(void)
+{
+ platform_driver_unregister(&latch_addr_flash_driver);
+}
+module_exit(latch_addr_flash_exit);
+
+MODULE_AUTHOR("David Griego <dgriego at mvista.com>");
+MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
+ "address lines being set board specifically");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mtd/latch-addr-flash.h b/include/linux/mtd/latch-addr-flash.h
new file mode 100644
index 0000000..c77e7c9
--- /dev/null
+++ b/include/linux/mtd/latch-addr-flash.h
@@ -0,0 +1,29 @@
+/*
+ * Interface for NOR flash driver whose high address lines are latched
+ *
+ * Copyright (C) 2008 MontaVista Software, Inc. <source at mvista.com>
+ *
+ * This file is licensed underthe terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+#ifndef __LATCH_ADDR_FLASH__
+#define __LATCH_ADDR_FLASH__
+
+struct map_info;
+struct mtd_partition;
+
+struct latch_addr_flash_data {
+ unsigned int width;
+ unsigned int size;
+
+ int (*init)(void *data, int cs);
+ void (*done)(void *data);
+ void (*set_window)(unsigned long offset, void *data);
+ void *data;
+
+ unsigned int nr_parts;
+ struct mtd_partition *parts;
+};
+
+#endif
--
1.5.6
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