projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| e29482e8 MN |
1 | /* |
| 2 | * ACPI helpers for GPIO API | |
| 3 | * | |
| 4 | * Copyright (C) 2012, Intel Corporation | |
| 5 | * Authors: Mathias Nyman <mathias.nyman@linux.intel.com> | |
| 6 | * Mika Westerberg <mika.westerberg@linux.intel.com> | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | */ | |
| 12 | ||
| 13 | #include <linux/errno.h> | |
| 14 | #include <linux/gpio.h> | |
| 15 | #include <linux/export.h> | |
| 16 | #include <linux/acpi_gpio.h> | |
| 17 | #include <linux/acpi.h> | |
| 18 | ||
| 19 | static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) | |
| 20 | { | |
| 21 | if (!gc->dev) | |
| 22 | return false; | |
| 23 | ||
| 24 | return ACPI_HANDLE(gc->dev) == data; | |
| 25 | } | |
| 26 | ||
| 27 | /** | |
| 28 | * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API | |
| 29 | * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") | |
| 30 | * @pin: ACPI GPIO pin number (0-based, controller-relative) | |
| 31 | * | |
| 32 | * Returns GPIO number to use with Linux generic GPIO API, or errno error value | |
| 33 | */ | |
| 34 | ||
| 35 | int acpi_get_gpio(char *path, int pin) | |
| 36 | { | |
| 37 | struct gpio_chip *chip; | |
| 38 | acpi_handle handle; | |
| 39 | acpi_status status; | |
| 40 | ||
| 41 | status = acpi_get_handle(NULL, path, &handle); | |
| 42 | if (ACPI_FAILURE(status)) | |
| 43 | return -ENODEV; | |
| 44 | ||
| 45 | chip = gpiochip_find(handle, acpi_gpiochip_find); | |
| 46 | if (!chip) | |
| 47 | return -ENODEV; | |
| 48 | ||
| 49 | if (!gpio_is_valid(chip->base + pin)) | |
| 50 | return -EINVAL; | |
| 51 | ||
| 52 | return chip->base + pin; | |
| 53 | } | |
| 54 | EXPORT_SYMBOL_GPL(acpi_get_gpio); |