diff options
Diffstat (limited to 'kernel/drivers/gpio/gpiolib-acpi.c')
| -rw-r--r-- | kernel/drivers/gpio/gpiolib-acpi.c | 214 |
1 files changed, 165 insertions, 49 deletions
diff --git a/kernel/drivers/gpio/gpiolib-acpi.c b/kernel/drivers/gpio/gpiolib-acpi.c index 725d16138..16a7b6816 100644 --- a/kernel/drivers/gpio/gpiolib-acpi.c +++ b/kernel/drivers/gpio/gpiolib-acpi.c @@ -68,7 +68,7 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) * GPIO controller driver. * * Typically the returned offset is same as @pin, but if the GPIO - * controller uses pin controller and the mapping is not contigous the + * controller uses pin controller and the mapping is not contiguous the * offset might be different. */ static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip, int pin) @@ -114,10 +114,11 @@ static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip, * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1") * @pin: ACPI GPIO pin number (0-based, controller-relative) * - * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR - * error value + * Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR + * error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO + * controller does not have gpiochip registered at the moment. This is to + * support probe deferral. */ - static struct gpio_desc *acpi_get_gpiod(char *path, int pin) { struct gpio_chip *chip; @@ -131,7 +132,7 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) chip = gpiochip_find(handle, acpi_gpiochip_find); if (!chip) - return ERR_PTR(-ENODEV); + return ERR_PTR(-EPROBE_DEFER); offset = acpi_gpiochip_pin_to_gpio_offset(chip, pin); if (offset < 0) @@ -303,10 +304,10 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) if (ACPI_FAILURE(status)) return; - INIT_LIST_HEAD(&acpi_gpio->events); acpi_walk_resources(handle, "_AEI", acpi_gpiochip_request_interrupt, acpi_gpio); } +EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts); /** * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts. @@ -346,6 +347,7 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) kfree(event); } } +EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts); int acpi_dev_add_driver_gpios(struct acpi_device *adev, const struct acpi_gpio_mapping *gpios) @@ -386,6 +388,8 @@ struct acpi_gpio_lookup { struct acpi_gpio_info info; int index; int pin_index; + bool active_low; + struct acpi_device *adev; struct gpio_desc *desc; int n; }; @@ -422,6 +426,65 @@ static int acpi_find_gpio(struct acpi_resource *ares, void *data) return 1; } +static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup, + struct acpi_gpio_info *info) +{ + struct list_head res_list; + int ret; + + INIT_LIST_HEAD(&res_list); + + ret = acpi_dev_get_resources(lookup->adev, &res_list, acpi_find_gpio, + lookup); + if (ret < 0) + return ret; + + acpi_dev_free_resource_list(&res_list); + + if (!lookup->desc) + return -ENOENT; + + if (info) { + *info = lookup->info; + if (lookup->active_low) + info->active_low = lookup->active_low; + } + return 0; +} + +static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode, + const char *propname, int index, + struct acpi_gpio_lookup *lookup) +{ + struct acpi_reference_args args; + int ret; + + memset(&args, 0, sizeof(args)); + ret = acpi_node_get_property_reference(fwnode, propname, index, &args); + if (ret) { + struct acpi_device *adev = to_acpi_device_node(fwnode); + + if (!adev) + return ret; + + if (!acpi_get_driver_gpio_data(adev, propname, index, &args)) + return ret; + } + /* + * The property was found and resolved, so need to lookup the GPIO based + * on returned args. + */ + lookup->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) + lookup->active_low = !!args.args[2]; + } + return 0; +} + /** * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources * @adev: pointer to a ACPI device to get GPIO from @@ -449,8 +512,6 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev, struct acpi_gpio_info *info) { struct acpi_gpio_lookup lookup; - struct list_head resource_list; - bool active_low = false; int ret; if (!adev) @@ -460,59 +521,94 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev, 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]; - } + ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev), + propname, index, &lookup); + if (ret) + return ERR_PTR(ret); - 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]); + dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n", + dev_name(&lookup.adev->dev), lookup.index, + lookup.pin_index, lookup.active_low); } else { dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index); + lookup.adev = adev; } - INIT_LIST_HEAD(&resource_list); - ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio, - &lookup); - if (ret < 0) + ret = acpi_gpio_resource_lookup(&lookup, info); + return ret ? ERR_PTR(ret) : lookup.desc; +} + +/** + * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources + * @fwnode: pointer to an ACPI firmware node to get the GPIO information from + * @propname: Property name of the GPIO + * @index: index of GpioIo/GpioInt resource (starting from %0) + * @info: info pointer to fill in (optional) + * + * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it. + * Otherwise (ie. it is a data-only non-device object), use the property-based + * GPIO lookup to get to the GPIO resource with the relevant information and use + * that to obtain the GPIO descriptor to return. + */ +struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode, + const char *propname, int index, + struct acpi_gpio_info *info) +{ + struct acpi_gpio_lookup lookup; + struct acpi_device *adev; + int ret; + + adev = to_acpi_device_node(fwnode); + if (adev) + return acpi_get_gpiod_by_index(adev, propname, index, info); + + if (!is_acpi_data_node(fwnode)) + return ERR_PTR(-ENODEV); + + if (!propname) + return ERR_PTR(-EINVAL); + + memset(&lookup, 0, sizeof(lookup)); + lookup.index = index; + + ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup); + if (ret) return ERR_PTR(ret); - acpi_dev_free_resource_list(&resource_list); + ret = acpi_gpio_resource_lookup(&lookup, info); + return ret ? ERR_PTR(ret) : lookup.desc; +} - if (lookup.desc && info) { - *info = lookup.info; - if (active_low) - info->active_low = active_low; - } +/** + * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number + * @adev: pointer to a ACPI device to get IRQ from + * @index: index of GpioInt resource (starting from %0) + * + * If the device has one or more GpioInt resources, this function can be + * used to translate from the GPIO offset in the resource to the Linux IRQ + * number. + * + * Return: Linux IRQ number (>%0) on success, negative errno on failure. + */ +int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index) +{ + int idx, i; - return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT); + for (i = 0, idx = 0; idx <= index; i++) { + struct acpi_gpio_info info; + struct gpio_desc *desc; + + desc = acpi_get_gpiod_by_index(adev, NULL, i, &info); + if (IS_ERR(desc)) + break; + if (info.gpioint && idx++ == index) + return gpiod_to_irq(desc); + } + return -ENOENT; } +EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get); static acpi_status acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address, @@ -571,6 +667,25 @@ acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address, break; } } + + /* + * The same GPIO can be shared between operation region and + * event but only if the access here is ACPI_READ. In that + * case we "borrow" the event GPIO instead. + */ + if (!found && agpio->sharable == ACPI_SHARED && + function == ACPI_READ) { + struct acpi_gpio_event *event; + + list_for_each_entry(event, &achip->events, node) { + if (event->pin == pin) { + desc = event->desc; + found = true; + break; + } + } + } + if (!found) { desc = gpiochip_request_own_desc(chip, pin, "ACPI:OpRegion"); @@ -687,6 +802,7 @@ void acpi_gpiochip_add(struct gpio_chip *chip) } acpi_gpio->chip = chip; + INIT_LIST_HEAD(&acpi_gpio->events); status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio); if (ACPI_FAILURE(status)) { |