From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/mtd/maps/gpio-addr-flash.c | 302 ++++++++++++++++++++++++++++++ 1 file changed, 302 insertions(+) create mode 100644 kernel/drivers/mtd/maps/gpio-addr-flash.c (limited to 'kernel/drivers/mtd/maps/gpio-addr-flash.c') diff --git a/kernel/drivers/mtd/maps/gpio-addr-flash.c b/kernel/drivers/mtd/maps/gpio-addr-flash.c new file mode 100644 index 000000000..2fb346091 --- /dev/null +++ b/kernel/drivers/mtd/maps/gpio-addr-flash.c @@ -0,0 +1,302 @@ +/* + * drivers/mtd/maps/gpio-addr-flash.c + * + * Handle the case where a flash device is mostly addressed using physical + * line and supplemented by GPIOs. This way you can hook up say a 8MiB flash + * to a 2MiB memory range and use the GPIOs to select a particular range. + * + * Copyright © 2000 Nicolas Pitre + * Copyright © 2005-2009 Analog Devices Inc. + * + * Enter bugs at http://blackfin.uclinux.org/ + * + * Licensed under the GPL-2 or later. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define pr_devinit(fmt, args...) \ + ({ static const char __fmt[] = fmt; printk(__fmt, ## args); }) + +#define DRIVER_NAME "gpio-addr-flash" +#define PFX DRIVER_NAME ": " + +/** + * struct async_state - keep GPIO flash state + * @mtd: MTD state for this mapping + * @map: MTD map state for this flash + * @gpio_count: number of GPIOs used to address + * @gpio_addrs: array of GPIOs to twiddle + * @gpio_values: cached GPIO values + * @win_size: dedicated memory size (if no GPIOs) + */ +struct async_state { + struct mtd_info *mtd; + struct map_info map; + size_t gpio_count; + unsigned *gpio_addrs; + int *gpio_values; + unsigned long win_size; +}; +#define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1) + +/** + * gf_set_gpios() - set GPIO address lines to access specified flash offset + * @state: GPIO flash state + * @ofs: desired offset to access + * + * Rather than call the GPIO framework every time, cache the last-programmed + * value. This speeds up sequential accesses (which are by far the most common + * type). We rely on the GPIO framework to treat non-zero value as high so + * that we don't have to normalize the bits. + */ +static void gf_set_gpios(struct async_state *state, unsigned long ofs) +{ + size_t i = 0; + int value; + ofs /= state->win_size; + do { + value = ofs & (1 << i); + if (state->gpio_values[i] != value) { + gpio_set_value(state->gpio_addrs[i], value); + state->gpio_values[i] = value; + } + } while (++i < state->gpio_count); +} + +/** + * gf_read() - read a word at the specified offset + * @map: MTD map state + * @ofs: desired offset to read + */ +static map_word gf_read(struct map_info *map, unsigned long ofs) +{ + struct async_state *state = gf_map_info_to_state(map); + uint16_t word; + map_word test; + + gf_set_gpios(state, ofs); + + word = readw(map->virt + (ofs % state->win_size)); + test.x[0] = word; + return test; +} + +/** + * gf_copy_from() - copy a chunk of data from the flash + * @map: MTD map state + * @to: memory to copy to + * @from: flash offset to copy from + * @len: how much to copy + * + * The "from" region may straddle more than one window, so toggle the GPIOs for + * each window region before reading its data. + */ +static void gf_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len) +{ + struct async_state *state = gf_map_info_to_state(map); + + int this_len; + + while (len) { + if ((from % state->win_size) + len > state->win_size) + this_len = state->win_size - (from % state->win_size); + else + this_len = len; + + gf_set_gpios(state, from); + memcpy_fromio(to, map->virt + (from % state->win_size), + this_len); + len -= this_len; + from += this_len; + to += this_len; + } +} + +/** + * gf_write() - write a word at the specified offset + * @map: MTD map state + * @ofs: desired offset to write + */ +static void gf_write(struct map_info *map, map_word d1, unsigned long ofs) +{ + struct async_state *state = gf_map_info_to_state(map); + uint16_t d; + + gf_set_gpios(state, ofs); + + d = d1.x[0]; + writew(d, map->virt + (ofs % state->win_size)); +} + +/** + * gf_copy_to() - copy a chunk of data to the flash + * @map: MTD map state + * @to: flash offset to copy to + * @from: memory to copy from + * @len: how much to copy + * + * See gf_copy_from() caveat. + */ +static void gf_copy_to(struct map_info *map, unsigned long to, + const void *from, ssize_t len) +{ + struct async_state *state = gf_map_info_to_state(map); + + int this_len; + + while (len) { + if ((to % state->win_size) + len > state->win_size) + this_len = state->win_size - (to % state->win_size); + else + this_len = len; + + gf_set_gpios(state, to); + memcpy_toio(map->virt + (to % state->win_size), from, len); + + len -= this_len; + to += this_len; + from += this_len; + } +} + +static const char * const part_probe_types[] = { + "cmdlinepart", "RedBoot", NULL }; + +/** + * gpio_flash_probe() - setup a mapping for a GPIO assisted flash + * @pdev: platform device + * + * The platform resource layout expected looks something like: + * struct mtd_partition partitions[] = { ... }; + * struct physmap_flash_data flash_data = { ... }; + * unsigned flash_gpios[] = { GPIO_XX, GPIO_XX, ... }; + * struct resource flash_resource[] = { + * { + * .name = "cfi_probe", + * .start = 0x20000000, + * .end = 0x201fffff, + * .flags = IORESOURCE_MEM, + * }, { + * .start = (unsigned long)flash_gpios, + * .end = ARRAY_SIZE(flash_gpios), + * .flags = IORESOURCE_IRQ, + * } + * }; + * struct platform_device flash_device = { + * .name = "gpio-addr-flash", + * .dev = { .platform_data = &flash_data, }, + * .num_resources = ARRAY_SIZE(flash_resource), + * .resource = flash_resource, + * ... + * }; + */ +static int gpio_flash_probe(struct platform_device *pdev) +{ + size_t i, arr_size; + struct physmap_flash_data *pdata; + struct resource *memory; + struct resource *gpios; + struct async_state *state; + + pdata = dev_get_platdata(&pdev->dev); + memory = platform_get_resource(pdev, IORESOURCE_MEM, 0); + gpios = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + + if (!memory || !gpios || !gpios->end) + return -EINVAL; + + arr_size = sizeof(int) * gpios->end; + state = kzalloc(sizeof(*state) + arr_size, GFP_KERNEL); + if (!state) + return -ENOMEM; + + /* + * We cast start/end to known types in the boards file, so cast + * away their pointer types here to the known types (gpios->xxx). + */ + state->gpio_count = gpios->end; + state->gpio_addrs = (void *)(unsigned long)gpios->start; + state->gpio_values = (void *)(state + 1); + state->win_size = resource_size(memory); + memset(state->gpio_values, 0xff, arr_size); + + state->map.name = DRIVER_NAME; + state->map.read = gf_read; + state->map.copy_from = gf_copy_from; + state->map.write = gf_write; + state->map.copy_to = gf_copy_to; + state->map.bankwidth = pdata->width; + state->map.size = state->win_size * (1 << state->gpio_count); + state->map.virt = ioremap_nocache(memory->start, state->map.size); + state->map.phys = NO_XIP; + state->map.map_priv_1 = (unsigned long)state; + + platform_set_drvdata(pdev, state); + + i = 0; + do { + if (gpio_request(state->gpio_addrs[i], DRIVER_NAME)) { + pr_devinit(KERN_ERR PFX "failed to request gpio %d\n", + state->gpio_addrs[i]); + while (i--) + gpio_free(state->gpio_addrs[i]); + kfree(state); + return -EBUSY; + } + gpio_direction_output(state->gpio_addrs[i], 0); + } while (++i < state->gpio_count); + + pr_devinit(KERN_NOTICE PFX "probing %d-bit flash bus\n", + state->map.bankwidth * 8); + state->mtd = do_map_probe(memory->name, &state->map); + if (!state->mtd) { + for (i = 0; i < state->gpio_count; ++i) + gpio_free(state->gpio_addrs[i]); + kfree(state); + return -ENXIO; + } + + + mtd_device_parse_register(state->mtd, part_probe_types, NULL, + pdata->parts, pdata->nr_parts); + + return 0; +} + +static int gpio_flash_remove(struct platform_device *pdev) +{ + struct async_state *state = platform_get_drvdata(pdev); + size_t i = 0; + do { + gpio_free(state->gpio_addrs[i]); + } while (++i < state->gpio_count); + mtd_device_unregister(state->mtd); + map_destroy(state->mtd); + kfree(state); + return 0; +} + +static struct platform_driver gpio_flash_driver = { + .probe = gpio_flash_probe, + .remove = gpio_flash_remove, + .driver = { + .name = DRIVER_NAME, + }, +}; + +module_platform_driver(gpio_flash_driver); + +MODULE_AUTHOR("Mike Frysinger "); +MODULE_DESCRIPTION("MTD map driver for flashes addressed physically and with gpios"); +MODULE_LICENSE("GPL"); -- cgit 1.2.3-korg