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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.c281
1 files changed, 0 insertions, 281 deletions
diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
deleted file mode 100644
index a20e85aa770e..000000000000
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ /dev/null
@@ -1,281 +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/gpio/consumer.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 win_mask(x) ((BIT(x)) - 1)
-
-#define DRIVER_NAME "gpio-addr-flash"
-
-/**
- * struct async_state - keep GPIO flash state
- * @mtd: MTD state for this mapping
- * @map: MTD map state for this flash
- * @gpios: Struct containing the array of GPIO descriptors
- * @gpio_values: cached GPIO values
- * @win_order: dedicated memory size (if no GPIOs)
- */
-struct async_state {
- struct mtd_info *mtd;
- struct map_info map;
- struct gpio_descs *gpios;
- unsigned int gpio_values;
- unsigned int win_order;
-};
-#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).
- */
-static void gf_set_gpios(struct async_state *state, unsigned long ofs)
-{
- int i;
-
- ofs >>= state->win_order;
-
- if (ofs == state->gpio_values)
- return;
-
- for (i = 0; i < state->gpios->ndescs; i++) {
- if ((ofs & BIT(i)) == (state->gpio_values & BIT(i)))
- continue;
-
- gpiod_set_value(state->gpios->desc[i], !!(ofs & BIT(i)));
- }
-
- state->gpio_values = ofs;
-}
-
-/**
- * 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 & win_mask(state->win_order)));
- 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) {
- this_len = from & win_mask(state->win_order);
- this_len = BIT(state->win_order) - this_len;
- this_len = min_t(int, len, this_len);
-
- gf_set_gpios(state, from);
- memcpy_fromio(to,
- map->virt + (from & win_mask(state->win_order)),
- 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 & win_mask(state->win_order)));
-}
-
-/**
- * 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) {
- this_len = to & win_mask(state->win_order);
- this_len = BIT(state->win_order) - this_len;
- this_len = min_t(int, len, this_len);
-
- gf_set_gpios(state, to);
- memcpy_toio(map->virt + (to & win_mask(state->win_order)),
- 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 = { ... };
- * static struct gpiod_lookup_table addr_flash_gpios = {
- * .dev_id = "gpio-addr-flash.0",
- * .table = {
- * GPIO_LOOKUP_IDX("gpio.0", 15, "addr", 0, GPIO_ACTIVE_HIGH),
- * GPIO_LOOKUP_IDX("gpio.0", 16, "addr", 1, GPIO_ACTIVE_HIGH),
- * );
- * };
- * gpiod_add_lookup_table(&addr_flash_gpios);
- *
- * struct resource flash_resource[] = {
- * {
- * .name = "cfi_probe",
- * .start = 0x20000000,
- * .end = 0x201fffff,
- * .flags = IORESOURCE_MEM,
- * },
- * };
- * 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)
-{
- struct physmap_flash_data *pdata;
- struct resource *memory;
- struct async_state *state;
-
- pdata = dev_get_platdata(&pdev->dev);
- memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-
- if (!memory)
- return -EINVAL;
-
- state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
- if (!state)
- return -ENOMEM;
-
- state->gpios = devm_gpiod_get_array(&pdev->dev, "addr", GPIOD_OUT_LOW);
- if (IS_ERR(state->gpios))
- return PTR_ERR(state->gpios);
-
- state->win_order = get_bitmask_order(resource_size(memory)) - 1;
-
- 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 = BIT(state->win_order + state->gpios->ndescs);
- state->map.virt = devm_ioremap_resource(&pdev->dev, memory);
- if (IS_ERR(state->map.virt))
- return PTR_ERR(state->map.virt);
-
- state->map.phys = NO_XIP;
- state->map.map_priv_1 = (unsigned long)state;
-
- platform_set_drvdata(pdev, state);
-
- dev_notice(&pdev->dev, "probing %d-bit flash bus\n",
- state->map.bankwidth * 8);
- state->mtd = do_map_probe(memory->name, &state->map);
- if (!state->mtd)
- return -ENXIO;
- state->mtd->dev.parent = &pdev->dev;
-
- 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);
-
- mtd_device_unregister(state->mtd);
- map_destroy(state->mtd);
- 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 v1.2.3 (git 2.39.0) at 2024-11-29 13:06:46 +0300