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path: root/drivers/mtd/maps/gpio-addr-flash.c
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Diffstat (limited to 'drivers/mtd/maps/gpio-addr-flash.c')
-rw-r--r--drivers/mtd/maps/gpio-addr-flash.c289
1 files changed, 0 insertions, 289 deletions
diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
deleted file mode 100644
index 5ede28294f9e..000000000000
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ /dev/null
@@ -1,289 +0,0 @@
-/*
- * 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 <nico@cam.org>
- * Copyright © 2005-2009 Analog Devices Inc.
- *
- * Enter bugs at http://blackfin.uclinux.org/
- *
- * Licensed under the GPL-2 or later.
- */
-
-#include <linux/gpio.h>
-#include <linux/init.h>
-#include <linux/io.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/mtd/physmap.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/types.h>
-
-#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
- *
- * We rely on the MTD layer to chunk up copies such that a single request here
- * will not cross a window size. This allows us to only wiggle the GPIOs once
- * before falling back to a normal memcpy. Reading the higher layer code shows
- * that this is indeed the case, but add a BUG_ON() to future proof.
- */
-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);
-
- gf_set_gpios(state, from);
-
- /* BUG if operation crosses the win_size */
- BUG_ON(!((from + len) % state->win_size <= (from + len)));
-
- /* operation does not cross the win_size, so one shot it */
- memcpy_fromio(to, map->virt + (from % state->win_size), 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);
-
- gf_set_gpios(state, to);
-
- /* BUG if operation crosses the win_size */
- BUG_ON(!((to + len) % state->win_size <= (to + len)));
-
- /* operation does not cross the win_size, so one shot it */
- memcpy_toio(map->virt + (to % state->win_size), from, 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 = pdev->dev.platform_data;
- 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 <vapier@gentoo.org>");
-MODULE_DESCRIPTION("MTD map driver for flashes addressed physically and with gpios");
-MODULE_LICENSE("GPL");
generated by cgit (git 2.34.1) at 2025-12-25 07:29:08 +0000