diff options
Diffstat (limited to 'drivers/gpio/gpiolib-acpi-core.c')
| -rw-r--r-- | drivers/gpio/gpiolib-acpi-core.c | 1417 |
1 files changed, 1417 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-acpi-core.c b/drivers/gpio/gpiolib-acpi-core.c new file mode 100644 index 000000000000..12b24a717e43 --- /dev/null +++ b/drivers/gpio/gpiolib-acpi-core.c @@ -0,0 +1,1417 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ACPI helpers for GPIO API + * + * Copyright (C) 2012, Intel Corporation + * Authors: Mathias Nyman <mathias.nyman@linux.intel.com> + * Mika Westerberg <mika.westerberg@linux.intel.com> + */ + +#include <linux/acpi.h> +#include <linux/dmi.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/mutex.h> +#include <linux/pinctrl/pinctrl.h> + +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/machine.h> + +#include "gpiolib.h" +#include "gpiolib-acpi.h" + +/** + * struct acpi_gpio_event - ACPI GPIO event handler data + * + * @node: list-entry of the events list of the struct acpi_gpio_chip + * @handle: handle of ACPI method to execute when the IRQ triggers + * @handler: handler function to pass to request_irq() when requesting the IRQ + * @pin: GPIO pin number on the struct gpio_chip + * @irq: Linux IRQ number for the event, for request_irq() / free_irq() + * @irqflags: flags to pass to request_irq() when requesting the IRQ + * @irq_is_wake: If the ACPI flags indicate the IRQ is a wakeup source + * @irq_requested:True if request_irq() has been done + * @desc: struct gpio_desc for the GPIO pin for this event + */ +struct acpi_gpio_event { + struct list_head node; + acpi_handle handle; + irq_handler_t handler; + unsigned int pin; + unsigned int irq; + unsigned long irqflags; + bool irq_is_wake; + bool irq_requested; + struct gpio_desc *desc; +}; + +struct acpi_gpio_connection { + struct list_head node; + unsigned int pin; + struct gpio_desc *desc; +}; + +struct acpi_gpio_chip { + /* + * ACPICA requires that the first field of the context parameter + * passed to acpi_install_address_space_handler() is large enough + * to hold struct acpi_connection_info. + */ + struct acpi_connection_info conn_info; + struct list_head conns; + struct mutex conn_lock; + struct gpio_chip *chip; + struct list_head events; + struct list_head deferred_req_irqs_list_entry; +}; + +/** + * struct acpi_gpio_info - ACPI GPIO specific information + * @adev: reference to ACPI device which consumes GPIO resource + * @flags: GPIO initialization flags + * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo + * @wake_capable: wake capability as provided by ACPI + * @pin_config: pin bias as provided by ACPI + * @polarity: interrupt polarity as provided by ACPI + * @triggering: triggering type as provided by ACPI + * @debounce: debounce timeout as provided by ACPI + * @quirks: Linux specific quirks as provided by struct acpi_gpio_mapping + */ +struct acpi_gpio_info { + struct acpi_device *adev; + enum gpiod_flags flags; + bool gpioint; + bool wake_capable; + int pin_config; + int polarity; + int triggering; + unsigned int debounce; + unsigned int quirks; +}; + +static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data) +{ + /* First check the actual GPIO device */ + if (device_match_acpi_handle(&gc->gpiodev->dev, data)) + return true; + + /* + * When the ACPI device is artificially split to the banks of GPIOs, + * where each of them is represented by a separate GPIO device, + * the firmware node of the physical device may not be shared among + * the banks as they may require different values for the same property, + * e.g., number of GPIOs in a certain bank. In such case the ACPI handle + * of a GPIO device is NULL and can not be used. Hence we have to check + * the parent device to be sure that there is no match before bailing + * out. + */ + if (gc->parent) + return device_match_acpi_handle(gc->parent, data); + + return false; +} + +/** + * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API + * @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. + * If the GPIO cannot be translated or there is an error an ERR_PTR is + * returned. + * + * Specifically returns %-EPROBE_DEFER if the referenced GPIO + * controller does not have GPIO chip registered at the moment. This is to + * support probe deferral. + */ +static struct gpio_desc *acpi_get_gpiod(char *path, unsigned int pin) +{ + acpi_handle handle; + acpi_status status; + + status = acpi_get_handle(NULL, path, &handle); + if (ACPI_FAILURE(status)) + return ERR_PTR(-ENODEV); + + struct gpio_device *gdev __free(gpio_device_put) = + gpio_device_find(handle, acpi_gpiochip_find); + if (!gdev) + return ERR_PTR(-EPROBE_DEFER); + + /* + * FIXME: keep track of the reference to the GPIO device somehow + * instead of putting it here. + */ + return gpio_device_get_desc(gdev, pin); +} + +static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) +{ + struct acpi_gpio_event *event = data; + + acpi_evaluate_object(event->handle, NULL, NULL, NULL); + + return IRQ_HANDLED; +} + +static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data) +{ + struct acpi_gpio_event *event = data; + + acpi_execute_simple_method(event->handle, NULL, event->pin); + + return IRQ_HANDLED; +} + +static void acpi_gpio_chip_dh(acpi_handle handle, void *data) +{ + /* The address of this function is used as a key. */ +} + +bool acpi_gpio_get_irq_resource(struct acpi_resource *ares, + struct acpi_resource_gpio **agpio) +{ + struct acpi_resource_gpio *gpio; + + if (ares->type != ACPI_RESOURCE_TYPE_GPIO) + return false; + + gpio = &ares->data.gpio; + if (gpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT) + return false; + + *agpio = gpio; + return true; +} +EXPORT_SYMBOL_GPL(acpi_gpio_get_irq_resource); + +/** + * acpi_gpio_get_io_resource - Fetch details of an ACPI resource if it is a GPIO + * I/O resource or return False if not. + * @ares: Pointer to the ACPI resource to fetch + * @agpio: Pointer to a &struct acpi_resource_gpio to store the output pointer + * + * Returns: + * %true if GpioIo resource is found, %false otherwise. + */ +bool acpi_gpio_get_io_resource(struct acpi_resource *ares, + struct acpi_resource_gpio **agpio) +{ + struct acpi_resource_gpio *gpio; + + if (ares->type != ACPI_RESOURCE_TYPE_GPIO) + return false; + + gpio = &ares->data.gpio; + if (gpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_IO) + return false; + + *agpio = gpio; + return true; +} +EXPORT_SYMBOL_GPL(acpi_gpio_get_io_resource); + +static void acpi_gpiochip_request_irq(struct acpi_gpio_chip *acpi_gpio, + struct acpi_gpio_event *event) +{ + struct device *parent = acpi_gpio->chip->parent; + int ret, value; + + ret = request_threaded_irq(event->irq, NULL, event->handler, + event->irqflags | IRQF_ONESHOT, "ACPI:Event", event); + if (ret) { + dev_err(parent, "Failed to setup interrupt handler for %d\n", event->irq); + return; + } + + if (event->irq_is_wake) + enable_irq_wake(event->irq); + + event->irq_requested = true; + + /* Make sure we trigger the initial state of edge-triggered IRQs */ + if (acpi_gpio_need_run_edge_events_on_boot() && + (event->irqflags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) { + value = gpiod_get_raw_value_cansleep(event->desc); + if (((event->irqflags & IRQF_TRIGGER_RISING) && value == 1) || + ((event->irqflags & IRQF_TRIGGER_FALLING) && value == 0)) + event->handler(event->irq, event); + } +} + +static void acpi_gpiochip_request_irqs(struct acpi_gpio_chip *acpi_gpio) +{ + struct acpi_gpio_event *event; + + list_for_each_entry(event, &acpi_gpio->events, node) + acpi_gpiochip_request_irq(acpi_gpio, event); +} + +static enum gpiod_flags +acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio, int polarity) +{ + /* GpioInt() implies input configuration */ + if (agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT) + return GPIOD_IN; + + switch (agpio->io_restriction) { + case ACPI_IO_RESTRICT_INPUT: + return GPIOD_IN; + case ACPI_IO_RESTRICT_OUTPUT: + /* + * ACPI GPIO resources don't contain an initial value for the + * GPIO. Therefore we deduce that value from the pull field + * and the polarity instead. If the pin is pulled up we assume + * default to be high, if it is pulled down we assume default + * to be low, otherwise we leave pin untouched. For active low + * polarity values will be switched. See also + * Documentation/firmware-guide/acpi/gpio-properties.rst. + */ + switch (agpio->pin_config) { + case ACPI_PIN_CONFIG_PULLUP: + return polarity == GPIO_ACTIVE_LOW ? GPIOD_OUT_LOW : GPIOD_OUT_HIGH; + case ACPI_PIN_CONFIG_PULLDOWN: + return polarity == GPIO_ACTIVE_LOW ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; + default: + break; + } + break; + default: + break; + } + + /* + * Assume that the BIOS has configured the direction and pull + * accordingly. + */ + return GPIOD_ASIS; +} + +static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip, + struct acpi_resource_gpio *agpio, + unsigned int index, + const char *label) +{ + int polarity = GPIO_ACTIVE_HIGH; + enum gpiod_flags flags = acpi_gpio_to_gpiod_flags(agpio, polarity); + unsigned int pin = agpio->pin_table[index]; + struct gpio_desc *desc; + int ret; + + desc = gpiochip_request_own_desc(chip, pin, label, polarity, flags); + if (IS_ERR(desc)) + return desc; + + /* ACPI uses hundredths of milliseconds units */ + ret = gpio_set_debounce_timeout(desc, agpio->debounce_timeout * 10); + if (ret) + dev_warn(chip->parent, + "Failed to set debounce-timeout for pin 0x%04X, err %d\n", + pin, ret); + + return desc; +} + +static bool acpi_gpio_irq_is_wake(struct device *parent, + const struct acpi_resource_gpio *agpio) +{ + unsigned int pin = agpio->pin_table[0]; + + if (agpio->wake_capable != ACPI_WAKE_CAPABLE) + return false; + + if (acpi_gpio_in_ignore_list(ACPI_GPIO_IGNORE_WAKE, dev_name(parent), pin)) { + dev_info(parent, "Ignoring wakeup on pin %u\n", pin); + return false; + } + + return true; +} + +/* Always returns AE_OK so that we keep looping over the resources */ +static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares, + void *context) +{ + struct acpi_gpio_chip *acpi_gpio = context; + struct gpio_chip *chip = acpi_gpio->chip; + struct acpi_resource_gpio *agpio; + acpi_handle handle, evt_handle; + struct acpi_gpio_event *event; + irq_handler_t handler = NULL; + struct gpio_desc *desc; + unsigned int pin; + int ret, irq; + + if (!acpi_gpio_get_irq_resource(ares, &agpio)) + return AE_OK; + + handle = ACPI_HANDLE(chip->parent); + pin = agpio->pin_table[0]; + + if (pin <= 255) { + char ev_name[8]; + sprintf(ev_name, "_%c%02X", + agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L', + pin); + if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle))) + handler = acpi_gpio_irq_handler; + } + if (!handler) { + if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle))) + handler = acpi_gpio_irq_handler_evt; + } + if (!handler) + return AE_OK; + + if (acpi_gpio_in_ignore_list(ACPI_GPIO_IGNORE_INTERRUPT, dev_name(chip->parent), pin)) { + dev_info(chip->parent, "Ignoring interrupt on pin %u\n", pin); + return AE_OK; + } + + desc = acpi_request_own_gpiod(chip, agpio, 0, "ACPI:Event"); + if (IS_ERR(desc)) { + dev_err(chip->parent, + "Failed to request GPIO for pin 0x%04X, err %ld\n", + pin, PTR_ERR(desc)); + return AE_OK; + } + + ret = gpiochip_lock_as_irq(chip, pin); + if (ret) { + dev_err(chip->parent, + "Failed to lock GPIO pin 0x%04X as interrupt, err %d\n", + pin, ret); + goto fail_free_desc; + } + + irq = gpiod_to_irq(desc); + if (irq < 0) { + dev_err(chip->parent, + "Failed to translate GPIO pin 0x%04X to IRQ, err %d\n", + pin, irq); + goto fail_unlock_irq; + } + + event = kzalloc(sizeof(*event), GFP_KERNEL); + if (!event) + goto fail_unlock_irq; + + event->irqflags = IRQF_ONESHOT; + if (agpio->triggering == ACPI_LEVEL_SENSITIVE) { + if (agpio->polarity == ACPI_ACTIVE_HIGH) + event->irqflags |= IRQF_TRIGGER_HIGH; + else + event->irqflags |= IRQF_TRIGGER_LOW; + } else { + switch (agpio->polarity) { + case ACPI_ACTIVE_HIGH: + event->irqflags |= IRQF_TRIGGER_RISING; + break; + case ACPI_ACTIVE_LOW: + event->irqflags |= IRQF_TRIGGER_FALLING; + break; + default: + event->irqflags |= IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING; + break; + } + } + + event->handle = evt_handle; + event->handler = handler; + event->irq = irq; + event->irq_is_wake = acpi_gpio_irq_is_wake(chip->parent, agpio); + event->pin = pin; + event->desc = desc; + + list_add_tail(&event->node, &acpi_gpio->events); + + return AE_OK; + +fail_unlock_irq: + gpiochip_unlock_as_irq(chip, pin); +fail_free_desc: + gpiochip_free_own_desc(desc); + + return AE_OK; +} + +/** + * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events + * @chip: GPIO chip + * + * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are + * handled by ACPI event methods which need to be called from the GPIO + * chip's interrupt handler. acpi_gpiochip_request_interrupts() finds out which + * GPIO pins have ACPI event methods and assigns interrupt handlers that calls + * the ACPI event methods for those pins. + */ +void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) +{ + struct acpi_gpio_chip *acpi_gpio; + acpi_handle handle; + acpi_status status; + + if (!chip->parent || !chip->to_irq) + return; + + handle = ACPI_HANDLE(chip->parent); + if (!handle) + return; + + status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio); + if (ACPI_FAILURE(status)) + return; + + if (acpi_quirk_skip_gpio_event_handlers()) + return; + + acpi_walk_resources(handle, METHOD_NAME__AEI, + acpi_gpiochip_alloc_event, acpi_gpio); + + if (acpi_gpio_add_to_deferred_list(&acpi_gpio->deferred_req_irqs_list_entry)) + return; + + acpi_gpiochip_request_irqs(acpi_gpio); +} +EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts); + +/** + * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts. + * @chip: GPIO chip + * + * Free interrupts associated with GPIO ACPI event method for the given + * GPIO chip. + */ +void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) +{ + struct acpi_gpio_chip *acpi_gpio; + struct acpi_gpio_event *event, *ep; + acpi_handle handle; + acpi_status status; + + if (!chip->parent || !chip->to_irq) + return; + + handle = ACPI_HANDLE(chip->parent); + if (!handle) + return; + + status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio); + if (ACPI_FAILURE(status)) + return; + + acpi_gpio_remove_from_deferred_list(&acpi_gpio->deferred_req_irqs_list_entry); + + list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) { + if (event->irq_requested) { + if (event->irq_is_wake) + disable_irq_wake(event->irq); + + free_irq(event->irq, event); + } + + gpiochip_unlock_as_irq(chip, event->pin); + gpiochip_free_own_desc(event->desc); + list_del(&event->node); + kfree(event); + } +} +EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts); + +void __init acpi_gpio_process_deferred_list(struct list_head *list) +{ + struct acpi_gpio_chip *acpi_gpio, *tmp; + + list_for_each_entry_safe(acpi_gpio, tmp, list, deferred_req_irqs_list_entry) + acpi_gpiochip_request_irqs(acpi_gpio); +} + +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); + +void acpi_dev_remove_driver_gpios(struct acpi_device *adev) +{ + if (adev) + adev->driver_gpios = NULL; +} +EXPORT_SYMBOL_GPL(acpi_dev_remove_driver_gpios); + +static void acpi_dev_release_driver_gpios(void *adev) +{ + acpi_dev_remove_driver_gpios(adev); +} + +int devm_acpi_dev_add_driver_gpios(struct device *dev, + const struct acpi_gpio_mapping *gpios) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + int ret; + + ret = acpi_dev_add_driver_gpios(adev, gpios); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, acpi_dev_release_driver_gpios, adev); +} +EXPORT_SYMBOL_GPL(devm_acpi_dev_add_driver_gpios); + +static bool acpi_get_driver_gpio_data(struct acpi_device *adev, + const char *name, int index, + struct fwnode_reference_args *args, + unsigned int *quirks) +{ + const struct acpi_gpio_mapping *gm; + + if (!adev || !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 *params = gm->data + index; + + args->fwnode = acpi_fwnode_handle(adev); + args->args[0] = params->crs_entry_index; + args->args[1] = params->line_index; + args->args[2] = params->active_low; + args->nargs = 3; + + *quirks = gm->quirks; + return true; + } + + return false; +} + +static int +__acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update) +{ + const enum gpiod_flags mask = + GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT | + GPIOD_FLAGS_BIT_DIR_VAL; + int ret = 0; + + /* + * Check if the BIOS has IoRestriction with explicitly set direction + * and update @flags accordingly. Otherwise use whatever caller asked + * for. + */ + if (update & GPIOD_FLAGS_BIT_DIR_SET) { + enum gpiod_flags diff = *flags ^ update; + + /* + * Check if caller supplied incompatible GPIO initialization + * flags. + * + * Return %-EINVAL to notify that firmware has different + * settings and we are going to use them. + */ + if (((*flags & GPIOD_FLAGS_BIT_DIR_SET) && (diff & GPIOD_FLAGS_BIT_DIR_OUT)) || + ((*flags & GPIOD_FLAGS_BIT_DIR_OUT) && (diff & GPIOD_FLAGS_BIT_DIR_VAL))) + ret = -EINVAL; + *flags = (*flags & ~mask) | (update & mask); + } + return ret; +} + +static int acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, + struct acpi_gpio_info *info) +{ + struct device *dev = &info->adev->dev; + enum gpiod_flags old = *flags; + int ret; + + ret = __acpi_gpio_update_gpiod_flags(&old, info->flags); + if (info->quirks & ACPI_GPIO_QUIRK_NO_IO_RESTRICTION) { + if (ret) + dev_warn(dev, FW_BUG "GPIO not in correct mode, fixing\n"); + } else { + if (ret) + dev_dbg(dev, "Override GPIO initialization flags\n"); + *flags = old; + } + + return ret; +} + +static int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags, + struct acpi_gpio_info *info) +{ + switch (info->pin_config) { + case ACPI_PIN_CONFIG_PULLUP: + *lookupflags |= GPIO_PULL_UP; + break; + case ACPI_PIN_CONFIG_PULLDOWN: + *lookupflags |= GPIO_PULL_DOWN; + break; + case ACPI_PIN_CONFIG_NOPULL: + *lookupflags |= GPIO_PULL_DISABLE; + break; + default: + break; + } + + if (info->polarity == GPIO_ACTIVE_LOW) + *lookupflags |= GPIO_ACTIVE_LOW; + + return 0; +} + +struct acpi_gpio_lookup { + struct acpi_gpio_params params; + struct acpi_gpio_info *info; + struct gpio_desc *desc; + int n; +}; + +static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data) +{ + struct acpi_gpio_lookup *lookup = data; + struct acpi_gpio_params *params = &lookup->params; + struct acpi_gpio_info *info = lookup->info; + + if (ares->type != ACPI_RESOURCE_TYPE_GPIO) + return 1; + + if (!lookup->desc) { + const struct acpi_resource_gpio *agpio = &ares->data.gpio; + bool gpioint = agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT; + struct gpio_desc *desc; + u16 pin_index; + + if (info->quirks & ACPI_GPIO_QUIRK_ONLY_GPIOIO && gpioint) + params->crs_entry_index++; + + if (lookup->n++ != params->crs_entry_index) + return 1; + + pin_index = params->line_index; + if (pin_index >= agpio->pin_table_length) + return 1; + + if (info->quirks & ACPI_GPIO_QUIRK_ABSOLUTE_NUMBER) + desc = gpio_to_desc(agpio->pin_table[pin_index]); + else + desc = acpi_get_gpiod(agpio->resource_source.string_ptr, + agpio->pin_table[pin_index]); + lookup->desc = desc; + info->pin_config = agpio->pin_config; + info->debounce = agpio->debounce_timeout; + info->gpioint = gpioint; + info->wake_capable = acpi_gpio_irq_is_wake(&info->adev->dev, agpio); + + /* + * Polarity and triggering are only specified for GpioInt + * resource. + * Note: we expect here: + * - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW + * - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH + */ + if (info->gpioint) { + info->polarity = agpio->polarity; + info->triggering = agpio->triggering; + } else { + info->polarity = params->active_low; + } + + info->flags = acpi_gpio_to_gpiod_flags(agpio, info->polarity); + } + + return 1; +} + +static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup) +{ + struct acpi_gpio_info *info = lookup->info; + struct acpi_device *adev = info->adev; + struct list_head res_list; + int ret; + + INIT_LIST_HEAD(&res_list); + + ret = acpi_dev_get_resources(adev, &res_list, + acpi_populate_gpio_lookup, + lookup); + if (ret < 0) + return ret; + + acpi_dev_free_resource_list(&res_list); + + if (!lookup->desc) + return -ENOENT; + + return 0; +} + +static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode, const char *propname, + struct acpi_gpio_lookup *lookup) +{ + struct fwnode_reference_args args; + struct acpi_gpio_params *params = &lookup->params; + struct acpi_gpio_info *info = lookup->info; + unsigned int index = params->crs_entry_index; + unsigned int quirks = 0; + int ret; + + memset(&args, 0, sizeof(args)); + + ret = __acpi_node_get_property_reference(fwnode, propname, index, 3, &args); + if (ret) { + struct acpi_device *adev; + + adev = to_acpi_device_node(fwnode); + if (!acpi_get_driver_gpio_data(adev, propname, index, &args, &quirks)) + return ret; + } + /* + * The property was found and resolved, so need to lookup the GPIO based + * on returned args. + */ + if (!to_acpi_device_node(args.fwnode)) + return -EINVAL; + if (args.nargs != 3) + return -EPROTO; + + params->crs_entry_index = args.args[0]; + params->line_index = args.args[1]; + params->active_low = !!args.args[2]; + + info->adev = to_acpi_device_node(args.fwnode); + info->quirks = quirks; + + return 0; +} + +/** + * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources + * @adev: pointer to a ACPI device to get GPIO from + * @propname: Property name of the GPIO (optional) + * @lookup: pointer to struct acpi_gpio_lookup to fill in + * + * Function goes through ACPI resources for @adev and based on @lookup.index looks + * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor, + * and returns it. @lookup.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). + * + * Returns: + * 0 on success, negative errno on failure. + * + * The @lookup is filled with GPIO descriptor to use with Linux generic GPIO API. + * If the GPIO cannot be translated an error will be returned. + * + * Note: if the GPIO resource has multiple entries in the pin list, this + * function only returns the first. + */ +static int acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname, + struct acpi_gpio_lookup *lookup) +{ + struct acpi_gpio_params *params = &lookup->params; + struct acpi_gpio_info *info = lookup->info; + int ret; + + if (propname) { + dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname); + + ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev), propname, lookup); + if (ret) + return ret; + + dev_dbg(&adev->dev, "GPIO: _DSD returned %s %u %u %u\n", + dev_name(&info->adev->dev), + params->crs_entry_index, params->line_index, params->active_low); + } else { + dev_dbg(&adev->dev, "GPIO: looking up %u in _CRS\n", params->crs_entry_index); + info->adev = adev; + } + + return acpi_gpio_resource_lookup(lookup); +} + +/** + * acpi_get_gpiod_from_data() - get a GPIO descriptor from ACPI data node + * @fwnode: pointer to an ACPI firmware node to get the GPIO information from + * @propname: Property name of the GPIO + * @lookup: pointer to struct acpi_gpio_lookup to fill in + * + * This function uses the property-based GPIO lookup to get to the GPIO + * resource with the relevant information from a data-only ACPI firmware node + * and uses that to obtain the GPIO descriptor to return. + * + * Returns: + * 0 on success, negative errno on failure. + * + * The @lookup is filled with GPIO descriptor to use with Linux generic GPIO API. + * If the GPIO cannot be translated an error will be returned. + */ +static int acpi_get_gpiod_from_data(struct fwnode_handle *fwnode, const char *propname, + struct acpi_gpio_lookup *lookup) +{ + int ret; + + if (!is_acpi_data_node(fwnode)) + return -ENODEV; + + if (!propname) + return -EINVAL; + + ret = acpi_gpio_property_lookup(fwnode, propname, lookup); + if (ret) + return ret; + + return acpi_gpio_resource_lookup(lookup); +} + +static bool acpi_can_fallback_to_crs(struct acpi_device *adev, + const char *con_id) +{ + /* If there is no ACPI device, there is no _CRS to fall back to */ + if (!adev) + return false; + + /* Never allow fallback if the device has properties */ + if (acpi_dev_has_props(adev) || adev->driver_gpios) + return false; + + return con_id == NULL; +} + +static struct gpio_desc * +__acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id, unsigned int idx, + bool can_fallback, struct acpi_gpio_info *info) +{ + struct acpi_device *adev = to_acpi_device_node(fwnode); + struct acpi_gpio_lookup lookup; + struct gpio_desc *desc; + char propname[32]; + int ret; + + memset(&lookup, 0, sizeof(lookup)); + lookup.params.crs_entry_index = idx; + lookup.info = info; + + /* Try first from _DSD */ + for_each_gpio_property_name(propname, con_id) { + if (adev) + ret = acpi_get_gpiod_by_index(adev, propname, &lookup); + else + ret = acpi_get_gpiod_from_data(fwnode, propname, &lookup); + if (ret) + continue; + + desc = lookup.desc; + if (PTR_ERR(desc) == -EPROBE_DEFER) + return desc; + + if (!IS_ERR(desc)) + return desc; + } + + /* Then from plain _CRS GPIOs */ + if (can_fallback) { + ret = acpi_get_gpiod_by_index(adev, NULL, &lookup); + if (ret) + return ERR_PTR(ret); + + return lookup.desc; + } + + return ERR_PTR(-ENOENT); +} + +struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode, + const char *con_id, + unsigned int idx, + enum gpiod_flags *dflags, + unsigned long *lookupflags) +{ + struct acpi_device *adev = to_acpi_device_node(fwnode); + bool can_fallback = acpi_can_fallback_to_crs(adev, con_id); + struct acpi_gpio_info info; + struct gpio_desc *desc; + + desc = __acpi_find_gpio(fwnode, con_id, idx, can_fallback, &info); + if (IS_ERR(desc)) + return desc; + + if (info.gpioint && + (*dflags == GPIOD_OUT_LOW || *dflags == GPIOD_OUT_HIGH)) { + dev_dbg(&adev->dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n"); + return ERR_PTR(-ENOENT); + } + + acpi_gpio_update_gpiod_flags(dflags, &info); + acpi_gpio_update_gpiod_lookup_flags(lookupflags, &info); + return desc; +} + +/** + * acpi_dev_gpio_irq_wake_get_by() - Find GpioInt and translate it to Linux IRQ number + * @adev: pointer to a ACPI device to get IRQ from + * @con_id: optional name of GpioInt resource + * @index: index of GpioInt resource (starting from %0) + * @wake_capable: Set to true if the IRQ is wake capable + * + * 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. + * + * The function is idempotent, though each time it runs it will configure GPIO + * pin direction according to the flags in GpioInt resource. + * + * The function takes optional @con_id parameter. If the resource has + * a @con_id in a property, then only those will be taken into account. + * + * The GPIO is considered wake capable if the GpioInt resource specifies + * SharedAndWake or ExclusiveAndWake. + * + * Returns: + * Linux IRQ number (> 0) on success, negative errno on failure. + */ +int acpi_dev_gpio_irq_wake_get_by(struct acpi_device *adev, const char *con_id, int index, + bool *wake_capable) +{ + struct fwnode_handle *fwnode = acpi_fwnode_handle(adev); + int idx, i; + unsigned int irq_flags; + int ret; + + for (i = 0, idx = 0; idx <= index; i++) { + struct acpi_gpio_info info; + struct gpio_desc *desc; + + /* Ignore -EPROBE_DEFER, it only matters if idx matches */ + desc = __acpi_find_gpio(fwnode, con_id, i, true, &info); + if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER) + return PTR_ERR(desc); + + if (info.gpioint && idx++ == index) { + unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT; + enum gpiod_flags dflags = GPIOD_ASIS; + char label[32]; + int irq; + + if (IS_ERR(desc)) + return PTR_ERR(desc); + + irq = gpiod_to_irq(desc); + if (irq < 0) + return irq; + + acpi_gpio_update_gpiod_flags(&dflags, &info); + acpi_gpio_update_gpiod_lookup_flags(&lflags, &info); + + snprintf(label, sizeof(label), "%pfwP GpioInt(%d)", fwnode, index); + ret = gpiod_set_consumer_name(desc, con_id ?: label); + if (ret) + return ret; + + ret = gpiod_configure_flags(desc, label, lflags, dflags); + if (ret < 0) + return ret; + + /* ACPI uses hundredths of milliseconds units */ + ret = gpio_set_debounce_timeout(desc, info.debounce * 10); + if (ret) + return ret; + + irq_flags = acpi_dev_get_irq_type(info.triggering, + info.polarity); + + /* + * If the IRQ is not already in use then set type + * if specified and different than the current one. + */ + if (can_request_irq(irq, irq_flags)) { + if (irq_flags != IRQ_TYPE_NONE && + irq_flags != irq_get_trigger_type(irq)) + irq_set_irq_type(irq, irq_flags); + } else { + dev_dbg(&adev->dev, "IRQ %d already in use\n", irq); + } + + /* avoid suspend issues with GPIOs when systems are using S3 */ + if (wake_capable && acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) + *wake_capable = info.wake_capable; + + return irq; + } + + } + return -ENOENT; +} +EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_wake_get_by); + +static acpi_status +acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address, + u32 bits, u64 *value, void *handler_context, + void *region_context) +{ + struct acpi_gpio_chip *achip = region_context; + struct gpio_chip *chip = achip->chip; + struct acpi_resource_gpio *agpio; + struct acpi_resource *ares; + u16 pin_index = address; + acpi_status status; + int length; + int i; + + status = acpi_buffer_to_resource(achip->conn_info.connection, + achip->conn_info.length, &ares); + if (ACPI_FAILURE(status)) + return status; + + if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) { + ACPI_FREE(ares); + return AE_BAD_PARAMETER; + } + + agpio = &ares->data.gpio; + + if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT && + function == ACPI_WRITE)) { + ACPI_FREE(ares); + return AE_BAD_PARAMETER; + } + + length = min_t(u16, agpio->pin_table_length, pin_index + bits); + for (i = pin_index; i < length; ++i) { + unsigned int pin = agpio->pin_table[i]; + struct acpi_gpio_connection *conn; + struct gpio_desc *desc; + bool found; + + mutex_lock(&achip->conn_lock); + + found = false; + list_for_each_entry(conn, &achip->conns, node) { + if (conn->pin == pin) { + found = true; + desc = conn->desc; + 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->shareable == 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 = acpi_request_own_gpiod(chip, agpio, i, "ACPI:OpRegion"); + if (IS_ERR(desc)) { + mutex_unlock(&achip->conn_lock); + status = AE_ERROR; + goto out; + } + + conn = kzalloc(sizeof(*conn), GFP_KERNEL); + if (!conn) { + gpiochip_free_own_desc(desc); + mutex_unlock(&achip->conn_lock); + status = AE_NO_MEMORY; + goto out; + } + + conn->pin = pin; + conn->desc = desc; + list_add_tail(&conn->node, &achip->conns); + } + + mutex_unlock(&achip->conn_lock); + + if (function == ACPI_WRITE) + gpiod_set_raw_value_cansleep(desc, !!(*value & BIT(i))); + else + *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i; + } + +out: + ACPI_FREE(ares); + return status; +} + +static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip) +{ + struct gpio_chip *chip = achip->chip; + acpi_handle handle = ACPI_HANDLE(chip->parent); + acpi_status status; + + INIT_LIST_HEAD(&achip->conns); + mutex_init(&achip->conn_lock); + status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO, + acpi_gpio_adr_space_handler, + NULL, achip); + if (ACPI_FAILURE(status)) + dev_err(chip->parent, + "Failed to install GPIO OpRegion handler\n"); +} + +static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip) +{ + struct gpio_chip *chip = achip->chip; + acpi_handle handle = ACPI_HANDLE(chip->parent); + struct acpi_gpio_connection *conn, *tmp; + acpi_status status; + + status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO, + acpi_gpio_adr_space_handler); + if (ACPI_FAILURE(status)) { + dev_err(chip->parent, + "Failed to remove GPIO OpRegion handler\n"); + return; + } + + list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) { + gpiochip_free_own_desc(conn->desc); + list_del(&conn->node); + kfree(conn); + } +} + +static struct gpio_desc * +acpi_gpiochip_parse_own_gpio(struct acpi_gpio_chip *achip, + struct fwnode_handle *fwnode, + const char **name, + unsigned long *lflags, + enum gpiod_flags *dflags) +{ + struct gpio_chip *chip = achip->chip; + struct gpio_desc *desc; + u32 gpios[2]; + int ret; + + *lflags = GPIO_LOOKUP_FLAGS_DEFAULT; + *dflags = GPIOD_ASIS; + *name = NULL; + + ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios, + ARRAY_SIZE(gpios)); + if (ret < 0) + return ERR_PTR(ret); + + desc = gpiochip_get_desc(chip, gpios[0]); + if (IS_ERR(desc)) + return desc; + + if (gpios[1]) + *lflags |= GPIO_ACTIVE_LOW; + + if (fwnode_property_present(fwnode, "input")) + *dflags |= GPIOD_IN; + else if (fwnode_property_present(fwnode, "output-low")) + *dflags |= GPIOD_OUT_LOW; + else if (fwnode_property_present(fwnode, "output-high")) + *dflags |= GPIOD_OUT_HIGH; + else + return ERR_PTR(-EINVAL); + + fwnode_property_read_string(fwnode, "line-name", name); + + return desc; +} + +static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip) +{ + struct gpio_chip *chip = achip->chip; + + device_for_each_child_node_scoped(chip->parent, fwnode) { + unsigned long lflags; + enum gpiod_flags dflags; + struct gpio_desc *desc; + const char *name; + int ret; + + if (!fwnode_property_present(fwnode, "gpio-hog")) + continue; + + desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name, + &lflags, &dflags); + if (IS_ERR(desc)) + continue; + + ret = gpiod_hog(desc, name, lflags, dflags); + if (ret) { + dev_err(chip->parent, "Failed to hog GPIO\n"); + return; + } + } +} + +void acpi_gpiochip_add(struct gpio_chip *chip) +{ + struct acpi_gpio_chip *acpi_gpio; + struct acpi_device *adev; + acpi_status status; + + if (!chip || !chip->parent) + return; + + adev = ACPI_COMPANION(chip->parent); + if (!adev) + return; + + acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL); + if (!acpi_gpio) { + dev_err(chip->parent, + "Failed to allocate memory for ACPI GPIO chip\n"); + return; + } + + acpi_gpio->chip = chip; + INIT_LIST_HEAD(&acpi_gpio->events); + INIT_LIST_HEAD(&acpi_gpio->deferred_req_irqs_list_entry); + + status = acpi_attach_data(adev->handle, acpi_gpio_chip_dh, acpi_gpio); + if (ACPI_FAILURE(status)) { + dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n"); + kfree(acpi_gpio); + return; + } + + acpi_gpiochip_request_regions(acpi_gpio); + acpi_gpiochip_scan_gpios(acpi_gpio); + acpi_dev_clear_dependencies(adev); +} + +void acpi_gpiochip_remove(struct gpio_chip *chip) +{ + struct acpi_gpio_chip *acpi_gpio; + acpi_handle handle; + acpi_status status; + + if (!chip || !chip->parent) + return; + + handle = ACPI_HANDLE(chip->parent); + if (!handle) + return; + + status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio); + if (ACPI_FAILURE(status)) { + dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n"); + return; + } + + acpi_gpiochip_free_regions(acpi_gpio); + + acpi_detach_data(handle, acpi_gpio_chip_dh); + kfree(acpi_gpio); +} + +static int acpi_gpio_package_count(const union acpi_object *obj) +{ + const union acpi_object *element = obj->package.elements; + const union acpi_object *end = element + obj->package.count; + unsigned int count = 0; + + while (element < end) { + switch (element->type) { + case ACPI_TYPE_LOCAL_REFERENCE: + element += 3; + fallthrough; + case ACPI_TYPE_INTEGER: + element++; + count++; + break; + + default: + return -EPROTO; + } + } + + return count; +} + +static int acpi_find_gpio_count(struct acpi_resource *ares, void *data) +{ + unsigned int *count = data; + + if (ares->type == ACPI_RESOURCE_TYPE_GPIO) + *count += ares->data.gpio.pin_table_length; + + return 1; +} + +/** + * acpi_gpio_count - count the GPIOs associated with a firmware node / function + * @fwnode: firmware node of the GPIO consumer + * @con_id: function within the GPIO consumer + * + * Returns: + * The number of GPIOs associated with a firmware node / function or %-ENOENT, + * if no GPIO has been assigned to the requested function. + */ +int acpi_gpio_count(const struct fwnode_handle *fwnode, const char *con_id) +{ + struct acpi_device *adev = to_acpi_device_node(fwnode); + const union acpi_object *obj; + const struct acpi_gpio_mapping *gm; + int count = -ENOENT; + int ret; + char propname[32]; + + /* Try first from _DSD */ + for_each_gpio_property_name(propname, con_id) { + ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY, &obj); + if (ret == 0) { + if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) + count = 1; + else if (obj->type == ACPI_TYPE_PACKAGE) + count = acpi_gpio_package_count(obj); + } else if (adev->driver_gpios) { + for (gm = adev->driver_gpios; gm->name; gm++) + if (strcmp(propname, gm->name) == 0) { + count = gm->size; + break; + } + } + if (count > 0) + break; + } + + /* Then from plain _CRS GPIOs */ + if (count < 0) { + struct list_head resource_list; + unsigned int crs_count = 0; + + if (!acpi_can_fallback_to_crs(adev, con_id)) + return count; + + INIT_LIST_HEAD(&resource_list); + acpi_dev_get_resources(adev, &resource_list, + acpi_find_gpio_count, &crs_count); + acpi_dev_free_resource_list(&resource_list); + if (crs_count > 0) + count = crs_count; + } + return count ? count : -ENOENT; +} |