gpio: add gpio-hog support
add gpio-hog support. GPIO hogging is a mechanism
providing automatic GPIO request and configuration
as part of the gpio-controller's driver probe function.
for more infos see:
doc/device-tree-bindings/gpio/gpio.txt
Signed-off-by: Heiko Schocher <hs@denx.de>
Tested-by: Michal Simek <michal.simek@xilinx.com> (zcu102)
Tested-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e36a8ab..fa1c997 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -14,6 +14,16 @@
particular GPIOs that they provide. The uclass interface
is defined in include/asm-generic/gpio.h.
+config DM_GPIO_HOG
+ bool "Enable GPIO hog support"
+ depends on DM_GPIO
+ default n
+ help
+ Enable gpio hog support
+ The GPIO chip may contain GPIO hog definitions. GPIO hogging
+ is a mechanism providing automatic GPIO request and config-
+ uration as part of the gpio-controller's driver probe function.
+
config ALTERA_PIO
bool "Altera PIO driver"
depends on DM_GPIO
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index da5e9ba..308d086 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -5,6 +5,9 @@
#include <common.h>
#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass-internal.h>
#include <dt-bindings/gpio/gpio.h>
#include <errno.h>
#include <fdtdec.h>
@@ -141,6 +144,118 @@
return gpio_xlate_offs_flags(desc->dev, desc, args);
}
+#if defined(CONFIG_DM_GPIO_HOG)
+
+struct gpio_hog_priv {
+ struct gpio_desc gpiod;
+};
+
+struct gpio_hog_data {
+ int gpiod_flags;
+ int value;
+ u32 val[2];
+};
+
+static int gpio_hog_ofdata_to_platdata(struct udevice *dev)
+{
+ struct gpio_hog_data *plat = dev_get_platdata(dev);
+ const char *nodename;
+ int ret;
+
+ plat->value = 0;
+ if (dev_read_bool(dev, "input")) {
+ plat->gpiod_flags = GPIOD_IS_IN;
+ } else if (dev_read_bool(dev, "output-high")) {
+ plat->value = 1;
+ plat->gpiod_flags = GPIOD_IS_OUT;
+ } else if (dev_read_bool(dev, "output-low")) {
+ plat->gpiod_flags = GPIOD_IS_OUT;
+ } else {
+ printf("%s: missing gpio-hog state.\n", __func__);
+ return -EINVAL;
+ }
+ ret = dev_read_u32_array(dev, "gpios", plat->val, 2);
+ if (ret) {
+ printf("%s: wrong gpios property, 2 values needed %d\n",
+ __func__, ret);
+ return ret;
+ }
+ nodename = dev_read_string(dev, "line-name");
+ if (!nodename)
+ nodename = dev_read_name(dev);
+ device_set_name(dev, nodename);
+
+ return 0;
+}
+
+static int gpio_hog_probe(struct udevice *dev)
+{
+ struct gpio_hog_data *plat = dev_get_platdata(dev);
+ struct gpio_hog_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = gpio_dev_request_index(dev->parent, dev->name, "gpio-hog",
+ plat->val[0], plat->gpiod_flags,
+ plat->val[1], &priv->gpiod);
+ if (ret < 0) {
+ debug("%s: node %s could not get gpio.\n", __func__,
+ dev->name);
+ return ret;
+ }
+ dm_gpio_set_dir(&priv->gpiod);
+ if (plat->gpiod_flags == GPIOD_IS_OUT)
+ dm_gpio_set_value(&priv->gpiod, plat->value);
+
+ return 0;
+}
+
+int gpio_hog_probe_all(void)
+{
+ struct udevice *dev;
+ int ret;
+
+ for (uclass_first_device(UCLASS_NOP, &dev);
+ dev;
+ uclass_find_next_device(&dev)) {
+ if (dev->driver == DM_GET_DRIVER(gpio_hog)) {
+ ret = device_probe(dev);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+struct gpio_desc *gpio_hog_lookup_name(const char *name)
+{
+ struct udevice *dev;
+
+ gpio_hog_probe_all();
+ if (!uclass_get_device_by_name(UCLASS_NOP, name, &dev)) {
+ struct gpio_hog_priv *priv = dev_get_priv(dev);
+
+ return &priv->gpiod;
+ }
+
+ return NULL;
+}
+
+U_BOOT_DRIVER(gpio_hog) = {
+ .name = "gpio_hog",
+ .id = UCLASS_NOP,
+ .ofdata_to_platdata = gpio_hog_ofdata_to_platdata,
+ .probe = gpio_hog_probe,
+ .priv_auto_alloc_size = sizeof(struct gpio_hog_priv),
+ .platdata_auto_alloc_size = sizeof(struct gpio_hog_data),
+};
+#else
+struct gpio_desc *gpio_hog_lookup_name(const char *name)
+{
+ return NULL;
+}
+#endif
+
int dm_gpio_request(struct gpio_desc *desc, const char *label)
{
struct udevice *dev = desc->dev;
@@ -640,22 +755,25 @@
return vector;
}
-static int gpio_request_tail(int ret, ofnode node,
+static int gpio_request_tail(int ret, const char *nodename,
struct ofnode_phandle_args *args,
const char *list_name, int index,
- struct gpio_desc *desc, int flags, bool add_index)
+ struct gpio_desc *desc, int flags,
+ bool add_index, struct udevice *dev)
{
- desc->dev = NULL;
+ desc->dev = dev;
desc->offset = 0;
desc->flags = 0;
if (ret)
goto err;
- ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
- &desc->dev);
- if (ret) {
- debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
- goto err;
+ if (!desc->dev) {
+ ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
+ &desc->dev);
+ if (ret) {
+ debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
+ goto err;
+ }
}
ret = gpio_find_and_xlate(desc, args);
if (ret) {
@@ -663,8 +781,7 @@
goto err;
}
ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
- ofnode_get_name(node),
- list_name, index);
+ nodename, list_name, index);
if (ret) {
debug("%s: dm_gpio_requestf failed\n", __func__);
goto err;
@@ -678,7 +795,7 @@
return 0;
err:
debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
- __func__, ofnode_get_name(node), list_name, index, ret);
+ __func__, nodename, list_name, index, ret);
return ret;
}
@@ -692,8 +809,8 @@
ret = ofnode_parse_phandle_with_args(node, list_name, "#gpio-cells", 0,
index, &args);
- return gpio_request_tail(ret, node, &args, list_name, index, desc,
- flags, add_index);
+ return gpio_request_tail(ret, ofnode_get_name(node), &args, list_name,
+ index, desc, flags, add_index, NULL);
}
int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
@@ -707,13 +824,14 @@
struct gpio_desc *desc, int flags)
{
struct ofnode_phandle_args args;
+ ofnode node;
int ret;
ret = dev_read_phandle_with_args(dev, list_name, "#gpio-cells", 0,
index, &args);
-
- return gpio_request_tail(ret, dev_ofnode(dev), &args, list_name,
- index, desc, flags, index > 0);
+ node = dev_ofnode(dev);
+ return gpio_request_tail(ret, ofnode_get_name(node), &args, list_name,
+ index, desc, flags, index > 0, NULL);
}
int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
@@ -854,8 +972,28 @@
return gpio_renumber(dev);
}
+int gpio_dev_request_index(struct udevice *dev, const char *nodename,
+ char *list_name, int index, int flags,
+ int dtflags, struct gpio_desc *desc)
+{
+ struct ofnode_phandle_args args;
+
+ args.node = ofnode_null();
+ args.args_count = 2;
+ args.args[0] = index;
+ args.args[1] = dtflags;
+
+ return gpio_request_tail(0, nodename, &args, list_name, index, desc,
+ flags, 0, dev);
+}
+
static int gpio_post_bind(struct udevice *dev)
{
+#if defined(CONFIG_DM_GPIO_HOG)
+ struct udevice *child;
+ ofnode node;
+#endif
+
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
static int reloc_done;
@@ -885,6 +1023,17 @@
reloc_done++;
}
#endif
+
+#if defined(CONFIG_DM_GPIO_HOG)
+ dev_for_each_subnode(node, dev) {
+ if (ofnode_read_bool(node, "gpio-hog")) {
+ const char *name = ofnode_get_name(node);
+
+ device_bind_driver_to_node(dev, "gpio_hog", name,
+ node, &child);
+ }
+ }
+#endif
return 0;
}