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
--- not yet started clean travis build, see result: https://travis-ci.org/hsdenx/u-boot-test/builds/537732421
Changes in v2: - move gpio_hog() call from post_probe() to post_bind() call. Check if current gpio device has gpio-hog definitions, if so, probe it.
doc/device-tree-bindings/gpio/gpio.txt | 52 ++++++++ drivers/gpio/Kconfig | 10 ++ drivers/gpio/gpio-uclass.c | 162 +++++++++++++++++++++++-- include/asm-generic/gpio.h | 24 ++++ 4 files changed, 236 insertions(+), 12 deletions(-)
diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt index f7a158d858..54f5ff6c7f 100644 --- a/doc/device-tree-bindings/gpio/gpio.txt +++ b/doc/device-tree-bindings/gpio/gpio.txt @@ -210,3 +210,55 @@ Example 2: Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2 are named "foo" and "bar". + +3) GPIO hog definitions +----------------------- + +The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism +providing automatic GPIO request and configuration as part of the +gpio-controller's driver probe function. + +Each GPIO hog definition is represented as a child node of the GPIO controller. +Required properties: +- gpio-hog: A property specifying that this child node represents a GPIO hog. +- gpios: Store the GPIO information (id, flags) for the GPIO to + affect. + + ! Not yet support more than one gpio ! + +Only one of the following properties scanned in the order shown below. +- input: A property specifying to set the GPIO direction as input. +- output-low A property specifying to set the GPIO direction as output with + the value low. +- output-high A property specifying to set the GPIO direction as output with + the value high. + +Example: + + tca6416@20 { + compatible = "ti,tca6416"; + reg = <0x20>; + #gpio-cells = <2>; + gpio-controller; + + env_reset { + gpio-hog; + input; + gpios = <6 GPIO_ACTIVE_LOW>; + }; + boot_rescue { + gpio-hog; + input; + gpios = <7 GPIO_ACTIVE_LOW>; + }; + }; + +For the above Example you can than access the gpio in your boardcode +with: + + desc = gpio_hog_lookup_name("boot_rescue.gpio-hog"); + if (desc) { + if (dm_gpio_get_value(desc)) + printf("\nBooting into Rescue System\n"); + else + printf("\nBoot normal\n"); diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index e36a8abc42..fa1c99700f 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -14,6 +14,16 @@ config DM_GPIO 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 da5e9ba6e5..4a21554d45 100644 --- a/drivers/gpio/gpio-uclass.c +++ b/drivers/gpio/gpio-uclass.c @@ -5,6 +5,7 @@
#include <common.h> #include <dm.h> +#include <dm/device-internal.h> #include <dt-bindings/gpio/gpio.h> #include <errno.h> #include <fdtdec.h> @@ -15,6 +16,17 @@
DECLARE_GLOBAL_DATA_PTR;
+struct gpio_priv_one { + struct list_head list; + char *name; + struct gpio_desc gpiod; +}; + +#if defined(CONFIG_DM_GPIO_HOG) +static struct list_head hogs; +static int probed_hogs; +#endif + /** * gpio_to_device() - Convert global GPIO number to device, number * @@ -141,6 +153,112 @@ static int gpio_find_and_xlate(struct gpio_desc *desc, return gpio_xlate_offs_flags(desc->dev, desc, args); }
+#if defined(CONFIG_DM_GPIO_HOG) +struct gpio_desc *gpio_hog_lookup_name(const char *name) +{ + struct list_head *entry; + struct gpio_priv_one *cur; + + list_for_each(entry, &hogs) { + cur = list_entry(entry, struct gpio_priv_one, list); + if (strcmp(cur->name, name) == 0) + return &cur->gpiod; + } + + return NULL; +} + +static int gpio_hog(struct udevice *dev) +{ + ofnode node; + int found = 0; + int ret; + struct gpio_dev_priv *uc_priv = NULL; + + if (!probed_hogs) { + INIT_LIST_HEAD(&hogs); + probed_hogs = 1; + } + dev_for_each_subnode(node, dev) { + if (ofnode_read_bool(node, "gpio-hog")) { + ret = device_probe(dev); + if (ret) + return ret; + found = 1; + break; + } + } + + if (!found) + return 0; + + uc_priv = dev_get_uclass_priv(dev); + if (!uc_priv) { + printf("%s: missing private data.\n", __func__); + return 0; + } + + /* scan for gpio-hog subnodes */ + dev_for_each_subnode(node, dev) { + int ret; + u32 val[2]; + int value = 0; + int gpiod_flags; + struct gpio_priv_one *new; + + if (!ofnode_read_bool(node, "gpio-hog")) + continue; + + if (ofnode_read_bool(node, "input")) { + gpiod_flags = GPIOD_IS_IN; + } else if (ofnode_read_bool(node, "output-high")) { + value = 1; + gpiod_flags = GPIOD_IS_OUT; + } else if (ofnode_read_bool(node, "output-low")) { + gpiod_flags = GPIOD_IS_OUT; + } else { + printf("%s: missing gpio-hog state.\n", __func__); + return -EINVAL; + } + + ret = ofnode_read_u32_array(node, "gpios", val, 2); + if (ret) { + printf("%s: wrong gpios property, 2 values needed, ret: %d\n", __func__, ret); + return ret; + } + + new = calloc(1, sizeof(struct gpio_priv_one)); + ret = gpio_dev_request_index(dev, node, "gpio-hog", val[0], + gpiod_flags, val[1], + &new->gpiod); + if (ret < 0) { + debug("%s: node %s could not get gpio.\n", __func__, + ofnode_get_name(node)); + free(new); + return ret; + } + + new->name = uc_priv->name[new->gpiod.offset]; + list_add_tail(&new->list, &hogs); + dm_gpio_set_dir(&new->gpiod); + if (gpiod_flags == GPIOD_IS_OUT) + dm_gpio_set_value(&new->gpiod, value); + } + + return 0; +} +#else +static int gpio_hog(struct udevice *dev) +{ + return 0; +} + +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; @@ -149,8 +267,9 @@ int dm_gpio_request(struct gpio_desc *desc, const char *label) int ret;
uc_priv = dev_get_uclass_priv(dev); - if (uc_priv->name[desc->offset]) - return -EBUSY; + if (uc_priv) + if (uc_priv->name[desc->offset]) + return -EBUSY; str = strdup(label); if (!str) return -ENOMEM; @@ -643,19 +762,22 @@ int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count) static int gpio_request_tail(int ret, ofnode node, 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) { @@ -693,7 +815,7 @@ static int _gpio_request_by_name_nodev(ofnode node, const char *list_name, index, &args);
return gpio_request_tail(ret, node, &args, list_name, index, desc, - flags, add_index); + flags, add_index, NULL); }
int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index, @@ -713,7 +835,7 @@ int gpio_request_by_name(struct udevice *dev, const char *list_name, int index, index, &args);
return gpio_request_tail(ret, dev_ofnode(dev), &args, list_name, - index, desc, flags, index > 0); + index, desc, flags, index > 0, NULL); }
int gpio_request_list_by_name_nodev(ofnode node, const char *list_name, @@ -854,6 +976,21 @@ static int gpio_pre_remove(struct udevice *dev) return gpio_renumber(dev); }
+int gpio_dev_request_index(struct udevice *dev, ofnode node, 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, node, &args, list_name, index, desc, + flags, 0, dev); +} + static int gpio_post_bind(struct udevice *dev) { #if defined(CONFIG_NEEDS_MANUAL_RELOC) @@ -885,7 +1022,8 @@ static int gpio_post_bind(struct udevice *dev) reloc_done++; } #endif - return 0; + + return gpio_hog(dev); }
UCLASS_DRIVER(gpio) = { diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index d03602696f..1894e497c7 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -348,6 +348,14 @@ const char *gpio_get_bank_info(struct udevice *dev, int *offset_count); */ int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
+/** + * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr. + * + * @name: Name to look up + * @return: Returns gpio_desc for gpio + */ +struct gpio_desc *gpio_hog_lookup_name(const char *name); + /** * gpio_lookup_name - Look up a GPIO name and return its details * @@ -503,6 +511,22 @@ int gpio_request_list_by_name_nodev(ofnode node, const char *list_name, struct gpio_desc *desc_list, int max_count, int flags);
+/** + * gpio_dev_request_index() - request single GPIO from gpio device + * + * @dev: GPIO device + * @ofnode: of node wich requests the GPIO + * @list_name: Name of GPIO list (e.g. "board-id-gpios") + * @index: Index number of the GPIO in that list use request (0=first) + * @flags: GPIOD_* flags + * @dtflags: GPIO flags read from DT + * @desc: GPIO descriotor filled from this function + * @return: return value from gpio_request_tail() + */ +int gpio_dev_request_index(struct udevice *dev, ofnode node, char *list_name, + int index, int flags, int dtflags, + struct gpio_desc *desc); + /** * dm_gpio_free() - Free a single GPIO *