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authorSimon Glass <sjg@chromium.org>2015-01-05 20:05:29 -0700
committerSimon Glass <sjg@chromium.org>2015-01-29 17:09:51 -0700
commit3669e0e759118fed3d371e2427b4b47d3969bfd0 (patch)
tree2f9831f33ac579dda2719ce5cc8bcbcd75c96f24 /drivers
parent0dac4d51f50e9252dbc00075cf65eeba57017926 (diff)
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dm: gpio: Add better functions to request GPIOs
At present U-Boot sort-of supports the standard way of reading GPIOs from device tree nodes, but the support is incomplete, a bit clunky and only works for GPIO bindings where #gpio-cells is 2. Add new functions to request GPIOs, taking full account of the device tree binding. These permit requesting a GPIO with a simple call like: gpio_request_by_name(dev, "cd-gpios", 0, &desc, GPIOD_IS_IN); This will request the GPIO, looking at the device's node which might be this, for example: cd-gpios = <&gpio TEGRA_GPIO(B, 3) GPIO_ACTIVE_LOW>; The GPIO will be set to input mode in this case and polarity will be honoured by the GPIO calls. It is also possible to request and free a list of GPIOs. Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpio-uclass.c166
-rw-r--r--drivers/gpio/sandbox.c20
2 files changed, 184 insertions, 2 deletions
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 0a4d9e4..a69bbd2 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -12,6 +12,8 @@
#include <asm/gpio.h>
#include <linux/ctype.h>
+DECLARE_GLOBAL_DATA_PTR;
+
/**
* gpio_to_device() - Convert global GPIO number to device, number
*
@@ -92,8 +94,8 @@ int gpio_lookup_name(const char *name, struct udevice **devp,
return 0;
}
-int gpio_find_and_xlate(struct gpio_desc *desc,
- struct fdtdec_phandle_args *args)
+static int gpio_find_and_xlate(struct gpio_desc *desc,
+ struct fdtdec_phandle_args *args)
{
struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
@@ -132,6 +134,17 @@ static int dm_gpio_request(struct gpio_desc *desc, const char *label)
return 0;
}
+static int dm_gpio_requestf(struct gpio_desc *desc, const char *fmt, ...)
+{
+ va_list args;
+ char buf[40];
+
+ va_start(args, fmt);
+ vscnprintf(buf, sizeof(buf), fmt, args);
+ va_end(args);
+ return dm_gpio_request(desc, buf);
+}
+
/**
* gpio_request() - [COMPAT] Request GPIO
* gpio: GPIO number
@@ -501,6 +514,155 @@ unsigned gpio_get_values_as_int(const int *gpio_num_array)
return vector;
}
+static int _gpio_request_by_name_nodev(const void *blob, int node,
+ const char *list_name, int index,
+ struct gpio_desc *desc, int flags,
+ bool add_index)
+{
+ struct fdtdec_phandle_args args;
+ int ret;
+
+ desc->dev = NULL;
+ desc->offset = 0;
+ ret = fdtdec_parse_phandle_with_args(blob, node, list_name,
+ "#gpio-cells", 0, index, &args);
+ if (ret) {
+ debug("%s: fdtdec_parse_phandle_with_args failed\n", __func__);
+ goto err;
+ }
+
+ ret = uclass_get_device_by_of_offset(UCLASS_GPIO, args.node,
+ &desc->dev);
+ if (ret) {
+ debug("%s: uclass_get_device_by_of_offset failed\n", __func__);
+ goto err;
+ }
+ ret = gpio_find_and_xlate(desc, &args);
+ if (ret) {
+ debug("%s: gpio_find_and_xlate failed\n", __func__);
+ goto err;
+ }
+ ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
+ fdt_get_name(blob, node, NULL),
+ list_name, index);
+ if (ret) {
+ debug("%s: dm_gpio_requestf failed\n", __func__);
+ goto err;
+ }
+ ret = dm_gpio_set_dir_flags(desc, flags | desc->flags);
+ if (ret) {
+ debug("%s: dm_gpio_set_dir failed\n", __func__);
+ goto err;
+ }
+
+ return 0;
+err:
+ debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
+ __func__, fdt_get_name(blob, node, NULL), list_name, index, ret);
+ return ret;
+}
+
+int gpio_request_by_name_nodev(const void *blob, int node,
+ const char *list_name, int index,
+ struct gpio_desc *desc, int flags)
+{
+ return _gpio_request_by_name_nodev(blob, node, list_name, index, desc,
+ flags, index > 0);
+}
+
+int gpio_request_by_name(struct udevice *dev, const char *list_name, int index,
+ struct gpio_desc *desc, int flags)
+{
+ /*
+ * This isn't ideal since we don't use dev->name in the debug()
+ * calls in gpio_request_by_name(), but we can do this until
+ * gpio_request_by_name_nodev() can be dropped.
+ */
+ return gpio_request_by_name_nodev(gd->fdt_blob, dev->of_offset,
+ list_name, index, desc, flags);
+}
+
+int gpio_request_list_by_name_nodev(const void *blob, int node,
+ const char *list_name,
+ struct gpio_desc *desc, int max_count,
+ int flags)
+{
+ int count;
+ int ret;
+
+ for (count = 0; ; count++) {
+ if (count >= max_count) {
+ ret = -ENOSPC;
+ goto err;
+ }
+ ret = _gpio_request_by_name_nodev(blob, node, list_name, count,
+ &desc[count], flags, true);
+ if (ret == -ENOENT)
+ break;
+ else if (ret)
+ goto err;
+ }
+
+ /* We ran out of GPIOs in the list */
+ return count;
+
+err:
+ gpio_free_list_nodev(desc, count - 1);
+
+ return ret;
+}
+
+int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
+ struct gpio_desc *desc, int max_count,
+ int flags)
+{
+ /*
+ * This isn't ideal since we don't use dev->name in the debug()
+ * calls in gpio_request_by_name(), but we can do this until
+ * gpio_request_list_by_name_nodev() can be dropped.
+ */
+ return gpio_request_list_by_name_nodev(gd->fdt_blob, dev->of_offset,
+ list_name, desc, max_count,
+ flags);
+}
+
+int gpio_get_list_count(struct udevice *dev, const char *list_name)
+{
+ int ret;
+
+ ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
+ list_name, "#gpio-cells", 0, -1,
+ NULL);
+ if (ret) {
+ debug("%s: Node '%s', property '%s', GPIO count failed: %d\n",
+ __func__, dev->name, list_name, ret);
+ }
+
+ return ret;
+}
+
+int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc)
+{
+ /* For now, we don't do any checking of dev */
+ return _dm_gpio_free(desc->dev, desc->offset);
+}
+
+int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count)
+{
+ int i;
+
+ /* For now, we don't do any checking of dev */
+ for (i = 0; i < count; i++)
+ dm_gpio_free(dev, &desc[i]);
+
+ return 0;
+}
+
+int gpio_free_list_nodev(struct gpio_desc *desc, int count)
+{
+ return gpio_free_list(NULL, desc, count);
+}
+
/* We need to renumber the GPIOs when any driver is probed/removed */
static int gpio_renumber(struct udevice *removed_dev)
{
diff --git a/drivers/gpio/sandbox.c b/drivers/gpio/sandbox.c
index 53c80d5..d564c25 100644
--- a/drivers/gpio/sandbox.c
+++ b/drivers/gpio/sandbox.c
@@ -8,6 +8,7 @@
#include <fdtdec.h>
#include <malloc.h>
#include <asm/gpio.h>
+#include <dt-bindings/gpio/gpio.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -130,12 +131,31 @@ static int sb_gpio_get_function(struct udevice *dev, unsigned offset)
return GPIOF_INPUT;
}
+static int sb_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
+ struct fdtdec_phandle_args *args)
+{
+ desc->offset = args->args[0];
+ if (args->args_count < 2)
+ return 0;
+ if (args->args[1] & GPIO_ACTIVE_LOW)
+ desc->flags |= GPIOD_ACTIVE_LOW;
+ if (args->args[1] & 2)
+ desc->flags |= GPIOD_IS_IN;
+ if (args->args[1] & 4)
+ desc->flags |= GPIOD_IS_OUT;
+ if (args->args[1] & 8)
+ desc->flags |= GPIOD_IS_OUT_ACTIVE;
+
+ return 0;
+}
+
static const struct dm_gpio_ops gpio_sandbox_ops = {
.direction_input = sb_gpio_direction_input,
.direction_output = sb_gpio_direction_output,
.get_value = sb_gpio_get_value,
.set_value = sb_gpio_set_value,
.get_function = sb_gpio_get_function,
+ .xlate = sb_gpio_xlate,
};
static int sandbox_gpio_ofdata_to_platdata(struct udevice *dev)