diff options
Diffstat (limited to 'drivers/gpio/gpiolib-acpi.c')
-rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 117 |
1 files changed, 103 insertions, 14 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 5be637d..c3bdaff 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -343,9 +343,45 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) } } +int acpi_dev_add_driver_gpios(struct acpi_device *adev, + const struct acpi_gpio_mapping *gpios) +{ + if (adev && gpios) { + adev->driver_gpios = gpios; + return 0; + } + return -EINVAL; +} +EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios); + +static bool acpi_get_driver_gpio_data(struct acpi_device *adev, + const char *name, int index, + struct acpi_reference_args *args) +{ + const struct acpi_gpio_mapping *gm; + + if (!adev->driver_gpios) + return false; + + for (gm = adev->driver_gpios; gm->name; gm++) + if (!strcmp(name, gm->name) && gm->data && index < gm->size) { + const struct acpi_gpio_params *par = gm->data + index; + + args->adev = adev; + args->args[0] = par->crs_entry_index; + args->args[1] = par->line_index; + args->args[2] = par->active_low; + args->nargs = 3; + return true; + } + + return false; +} + struct acpi_gpio_lookup { struct acpi_gpio_info info; int index; + int pin_index; struct gpio_desc *desc; int n; }; @@ -359,13 +395,24 @@ static int acpi_find_gpio(struct acpi_resource *ares, void *data) if (lookup->n++ == lookup->index && !lookup->desc) { const struct acpi_resource_gpio *agpio = &ares->data.gpio; + int pin_index = lookup->pin_index; + + if (pin_index >= agpio->pin_table_length) + return 1; lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr, - agpio->pin_table[0]); + agpio->pin_table[pin_index]); lookup->info.gpioint = agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT; - lookup->info.active_low = - agpio->polarity == ACPI_ACTIVE_LOW; + + /* + * ActiveLow is only specified for GpioInt resource. If + * GpioIo is used then the only way to set the flag is + * to use _DSD "gpios" property. + */ + if (lookup->info.gpioint) + lookup->info.active_low = + agpio->polarity == ACPI_ACTIVE_LOW; } return 1; @@ -373,40 +420,79 @@ static int acpi_find_gpio(struct acpi_resource *ares, void *data) /** * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources - * @dev: pointer to a device to get GPIO from + * @adev: pointer to a ACPI device to get GPIO from + * @propname: Property name of the GPIO (optional) * @index: index of GpioIo/GpioInt resource (starting from %0) * @info: info pointer to fill in (optional) * - * Function goes through ACPI resources for @dev and based on @index looks + * Function goes through ACPI resources for @adev and based on @index looks * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor, * and returns it. @index matches GpioIo/GpioInt resources only so if there * are total %3 GPIO resources, the index goes from %0 to %2. * + * If @propname is specified the GPIO is looked using device property. In + * that case @index is used to select the GPIO entry in the property value + * (in case of multiple). + * * If the GPIO cannot be translated or there is an error an ERR_PTR is * returned. * * Note: if the GPIO resource has multiple entries in the pin list, this * function only returns the first. */ -struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index, +struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev, + const char *propname, int index, struct acpi_gpio_info *info) { struct acpi_gpio_lookup lookup; struct list_head resource_list; - struct acpi_device *adev; - acpi_handle handle; + bool active_low = false; int ret; - if (!dev) - return ERR_PTR(-EINVAL); - - handle = ACPI_HANDLE(dev); - if (!handle || acpi_bus_get_device(handle, &adev)) + if (!adev) return ERR_PTR(-ENODEV); memset(&lookup, 0, sizeof(lookup)); lookup.index = index; + if (propname) { + struct acpi_reference_args args; + + dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname); + + memset(&args, 0, sizeof(args)); + ret = acpi_dev_get_property_reference(adev, propname, + index, &args); + if (ret) { + bool found = acpi_get_driver_gpio_data(adev, propname, + index, &args); + if (!found) + return ERR_PTR(ret); + } + + /* + * The property was found and resolved so need to + * lookup the GPIO based on returned args instead. + */ + adev = args.adev; + if (args.nargs >= 2) { + lookup.index = args.args[0]; + lookup.pin_index = args.args[1]; + /* + * 3rd argument, if present is used to + * specify active_low. + */ + if (args.nargs >= 3) + active_low = !!args.args[2]; + } + + dev_dbg(&adev->dev, "GPIO: _DSD returned %s %zd %llu %llu %llu\n", + dev_name(&adev->dev), args.nargs, + args.args[0], args.args[1], args.args[2]); + } else { + dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index); + } + INIT_LIST_HEAD(&resource_list); ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio, &lookup); @@ -415,8 +501,11 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index, acpi_dev_free_resource_list(&resource_list); - if (lookup.desc && info) + if (lookup.desc && info) { *info = lookup.info; + if (active_low) + info->active_low = active_low; + } return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT); } |