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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.c146
1 files changed, 61 insertions, 85 deletions
diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 9d9723693217..a20e85aa770e 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -14,6 +14,7 @@
*/
#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -25,28 +26,24 @@
#include <linux/slab.h>
#include <linux/types.h>
-#define pr_devinit(fmt, args...) \
- ({ static const char __fmt[] = fmt; printk(__fmt, ## args); })
+#define win_mask(x) ((BIT(x)) - 1)
#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
+ * @gpios: Struct containing the array of GPIO descriptors
* @gpio_values: cached GPIO values
- * @win_size: dedicated memory size (if no GPIOs)
+ * @win_order: 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;
+ 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)
@@ -57,21 +54,25 @@ struct async_state {
*
* 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.
+ * type).
*/
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);
+ 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;
}
/**
@@ -87,7 +88,7 @@ static map_word gf_read(struct map_info *map, unsigned long ofs)
gf_set_gpios(state, ofs);
- word = readw(map->virt + (ofs % state->win_size));
+ word = readw(map->virt + (ofs & win_mask(state->win_order)));
test.x[0] = word;
return test;
}
@@ -109,14 +110,14 @@ static void gf_copy_from(struct map_info *map, void *to, unsigned long from, ssi
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;
+ 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 % state->win_size),
- this_len);
+ memcpy_fromio(to,
+ map->virt + (from & win_mask(state->win_order)),
+ this_len);
len -= this_len;
from += this_len;
to += this_len;
@@ -136,7 +137,7 @@ static void gf_write(struct map_info *map, map_word d1, unsigned long ofs)
gf_set_gpios(state, ofs);
d = d1.x[0];
- writew(d, map->virt + (ofs % state->win_size));
+ writew(d, map->virt + (ofs & win_mask(state->win_order)));
}
/**
@@ -156,13 +157,13 @@ static void gf_copy_to(struct map_info *map, unsigned long to,
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;
+ 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 % state->win_size), from, len);
+ memcpy_toio(map->virt + (to & win_mask(state->win_order)),
+ from, len);
len -= this_len;
to += this_len;
@@ -180,18 +181,22 @@ static const char * const part_probe_types[] = {
* 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, ... };
+ * 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,
- * }, {
- * .start = (unsigned long)flash_gpios,
- * .end = ARRAY_SIZE(flash_gpios),
- * .flags = IORESOURCE_IRQ,
- * }
+ * },
* };
* struct platform_device flash_device = {
* .name = "gpio-addr-flash",
@@ -203,33 +208,25 @@ static const char * const part_probe_types[] = {
*/
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)
+ if (!memory)
return -EINVAL;
- arr_size = sizeof(int) * gpios->end;
- state = kzalloc(sizeof(*state) + arr_size, GFP_KERNEL);
+ state = devm_kzalloc(&pdev->dev, sizeof(*state), 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->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;
@@ -237,38 +234,21 @@ static int gpio_flash_probe(struct platform_device *pdev)
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);
- if (!state->map.virt)
- return -ENOMEM;
+ 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);
- 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);
+ 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) {
- for (i = 0; i < state->gpio_count; ++i)
- gpio_free(state->gpio_addrs[i]);
- kfree(state);
+ if (!state->mtd)
return -ENXIO;
- }
state->mtd->dev.parent = &pdev->dev;
mtd_device_parse_register(state->mtd, part_probe_types, NULL,
@@ -280,13 +260,9 @@ static int gpio_flash_probe(struct platform_device *pdev)
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;
}