diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 85 |
1 files changed, 81 insertions, 4 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e8e98ca25ec7..58659dbe702a 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1505,14 +1505,36 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) { + static const char * const suffixes[] = { "gpios", "gpio" }; + struct acpi_device *adev = ACPI_COMPANION(dev); struct acpi_gpio_info info; struct gpio_desc *desc; + char propname[32]; + int i; - desc = acpi_get_gpiod_by_index(dev, idx, &info); - if (IS_ERR(desc)) - return desc; + /* Try first from _DSD */ + for (i = 0; i < ARRAY_SIZE(suffixes); i++) { + if (con_id && strcmp(con_id, "gpios")) { + snprintf(propname, sizeof(propname), "%s-%s", + con_id, suffixes[i]); + } else { + snprintf(propname, sizeof(propname), "%s", + suffixes[i]); + } + + desc = acpi_get_gpiod_by_index(adev, propname, idx, &info); + if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER)) + break; + } - if (info.gpioint && info.active_low) + /* Then from plain _CRS GPIOs */ + if (IS_ERR(desc)) { + desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info); + if (IS_ERR(desc)) + return desc; + } + + if (info.active_low) *flags |= GPIO_ACTIVE_LOW; return desc; @@ -1713,6 +1735,61 @@ struct gpio_desc *__must_check __gpiod_get_index(struct device *dev, EXPORT_SYMBOL_GPL(__gpiod_get_index); /** + * fwnode_get_named_gpiod - obtain a GPIO from firmware node + * @fwnode: handle of the firmware node + * @propname: name of the firmware property representing the GPIO + * + * This function can be used for drivers that get their configuration + * from firmware. + * + * Function properly finds the corresponding GPIO using whatever is the + * underlying firmware interface and then makes sure that the GPIO + * descriptor is requested before it is returned to the caller. + * + * In case of error an ERR_PTR() is returned. + */ +struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, + const char *propname) +{ + struct gpio_desc *desc = ERR_PTR(-ENODEV); + bool active_low = false; + int ret; + + if (!fwnode) + return ERR_PTR(-EINVAL); + + if (is_of_node(fwnode)) { + enum of_gpio_flags flags; + + desc = of_get_named_gpiod_flags(of_node(fwnode), propname, 0, + &flags); + if (!IS_ERR(desc)) + active_low = flags & OF_GPIO_ACTIVE_LOW; + } else if (is_acpi_node(fwnode)) { + struct acpi_gpio_info info; + + desc = acpi_get_gpiod_by_index(acpi_node(fwnode), propname, 0, + &info); + if (!IS_ERR(desc)) + active_low = info.active_low; + } + + if (IS_ERR(desc)) + return desc; + + ret = gpiod_request(desc, NULL); + if (ret) + return ERR_PTR(ret); + + /* Only value flag can be set from both DT and ACPI is active_low */ + if (active_low) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + + return desc; +} +EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); + +/** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs |