@@ -43,7 +43,7 @@ struct async_state {
struct map_info map;
size_t gpio_count;
unsigned *gpio_addrs;
- int *gpio_values;
+ unsigned int gpio_values;
unsigned int win_order;
};
#define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1)
@@ -55,22 +55,25 @@ 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;
+ int i;
ofs >>= state->win_order;
- 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);
+
+ if (ofs == state->gpio_values)
+ return;
+
+ for (i = 0; i < state->gpio_count; i++) {
+ if ((ofs & BIT(i)) == (state->gpio_values & BIT(i)))
+ continue;
+
+ gpio_set_value(state->gpio_addrs[i], !!(ofs & BIT(i)));
+ }
+
+ state->gpio_values = ofs;
}
/**
@@ -202,7 +205,7 @@ static const char * const part_probe_types[] = {
*/
static int gpio_flash_probe(struct platform_device *pdev)
{
- size_t i, arr_size;
+ size_t i;
struct physmap_flash_data *pdata;
struct resource *memory;
struct resource *gpios;
@@ -215,8 +218,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
if (!memory || !gpios || !gpios->end)
return -EINVAL;
- arr_size = sizeof(int) * gpios->end;
- state = devm_kzalloc(&pdev->dev, sizeof(*state) + arr_size, GFP_KERNEL);
+ state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
if (!state)
return -ENOMEM;
@@ -226,9 +228,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
*/
state->gpio_count = gpios->end;
state->gpio_addrs = (void *)(unsigned long)gpios->start;
- state->gpio_values = (void *)(state + 1);
state->win_order = get_bitmask_order(resource_size(memory)) - 1;
- memset(state->gpio_values, 0xff, arr_size);
state->map.name = DRIVER_NAME;
state->map.read = gf_read;
By replacing the array with an integer we can avoid completely the bit comparison loop if the value has not changed (by far the most common case). Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> --- drivers/mtd/maps/gpio-addr-flash.c | 34 +++++++++++++++--------------- 1 file changed, 17 insertions(+), 17 deletions(-)