From dcfb81d61da1367e52f7f7e3ceff0d0044c3c7ee Mon Sep 17 00:00:00 2001 From: David Griego Date: Tue, 30 Nov 2010 15:32:05 +0530 Subject: [PATCH] mtd: NOR flash driver for OMAP-L137/AM17x 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: David Griego Signed-off-by: Aleksey Makarov Signed-off-by: Sergei Shtylyov Signed-off-by: Savinay Dharmappa Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/maps/Kconfig | 9 + drivers/mtd/maps/Makefile | 1 + drivers/mtd/maps/latch-addr-flash.c | 272 +++++++++++++++++++++++++++ include/linux/mtd/latch-addr-flash.h | 29 +++ 4 files changed, 311 insertions(+) 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 803072a71ed..44b1f46458c 100644 --- a/drivers/mtd/maps/Kconfig +++ b/drivers/mtd/maps/Kconfig @@ -552,4 +552,13 @@ 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 c7869c7a6b1..08533bd5cba 100644 --- a/drivers/mtd/maps/Makefile +++ b/drivers/mtd/maps/Makefile @@ -59,3 +59,4 @@ 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_BCM963XX) += bcm963xx-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 00000000000..ee254808533 --- /dev/null +++ b/drivers/mtd/maps/latch-addr-flash.c @@ -0,0 +1,272 @@ +/* + * Interface for NOR flash driver whose high address lines are latched + * + * Copyright © 2000 Nicolas Pitre + * Copyright © 2005-2008 Analog Devices Inc. + * Copyright © 2008 MontaVista Software, Inc. + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#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 char *rom_probe_types[] = { "cfi_probe", NULL }; + +static 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); + 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, + (const char **)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 "); +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 00000000000..e94b8e12807 --- /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 © 2008 MontaVista Software, Inc. + * + * 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. + */ +#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 -- 2.20.1