/* * ACPI helpers for GPIO API * * Copyright (C) 2012, Intel Corporation * Authors: Mathias Nyman * Mika Westerberg * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include "gpiolib.h" struct acpi_gpio_event { struct list_head node; acpi_handle handle; unsigned int pin; unsigned int irq; 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; }; static int acpi_gpiochip_find(struct gpio_chip *gc, void *data) { if (!gc->dev) return false; return ACPI_HANDLE(gc->dev) == data; } #ifdef CONFIG_PINCTRL /** * acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO * @chip: GPIO chip * @pin: ACPI GPIO pin number from GpioIo/GpioInt resource * * Function takes ACPI GpioIo/GpioInt pin number as a parameter and * translates it to a corresponding offset suitable to be passed to a * 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 * offset might be different. */ static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip, int pin) { struct gpio_pin_range *pin_range; /* If there are no ranges in this chip, use 1:1 mapping */ if (list_empty(&chip->pin_ranges)) return pin; list_for_each_entry(pin_range, &chip->pin_ranges, node) { const struct pinctrl_gpio_range *range = &pin_range->range; int i; if (range->pins) { for (i = 0; i < range->npins; i++) { if (range->pins[i] == pin) return range->base + i - chip->base; } } else { if (pin >= range->pin_base && pin < range->pin_base + range->npins) { unsigned gpio_base; gpio_base = range->base - chip->base; return gpio_base + pin - range->pin_base; } } } return -EINVAL; } #else static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip, int pin) { return pin; } #endif /** * 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, or ERR_PTR * error value */ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) { struct gpio_chip *chip; acpi_handle handle; acpi_status status; int offset; status = acpi_get_handle(NULL, path, &handle); if (ACPI_FAILURE(status)) return ERR_PTR(-ENODEV); chip = gpiochip_find(handle, acpi_gpiochip_find); if (!chip) return ERR_PTR(-ENODEV); offset = acpi_gpiochip_pin_to_gpio_offset(chip, pin); if (offset < 0) return ERR_PTR(offset); return gpiochip_get_desc(chip, offset); } 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. */ } static acpi_status acpi_gpiochip_request_interrupt(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 long irqflags; int ret, pin, irq; if (ares->type != ACPI_RESOURCE_TYPE_GPIO) return AE_OK; agpio = &ares->data.gpio; if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT) return AE_OK; handle = ACPI_HANDLE(chip->dev); pin = agpio->pin_table[0]; if (pin <= 255) { char ev_name[5]; 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_BAD_PARAMETER; desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event"); if (IS_ERR(desc)) { dev_err(chip->dev, "Failed to request GPIO\n"); return AE_ERROR; } gpiod_direction_input(desc); ret = gpiochip_lock_as_irq(chip, pin); if (ret) { dev_err(chip->dev, "Failed to lock GPIO as interrupt\n"); goto fail_free_desc; } irq = gpiod_to_irq(desc); if (irq < 0) { dev_err(chip->dev, "Failed to translate GPIO to IRQ\n"); goto fail_unlock_irq; } irqflags = IRQF_ONESHOT; if (agpio->triggering == ACPI_LEVEL_SENSITIVE) { if (agpio->polarity == ACPI_ACTIVE_HIGH) irqflags |= IRQF_TRIGGER_HIGH; else irqflags |= IRQF_TRIGGER_LOW; } else { switch (agpio->polarity) { case ACPI_ACTIVE_HIGH: irqflags |= IRQF_TRIGGER_RISING; break; case ACPI_ACTIVE_LOW: irqflags |= IRQF_TRIGGER_FALLING; break; default: irqflags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING; break; } } event = kzalloc(sizeof(*event), GFP_KERNEL); if (!event) goto fail_unlock_irq; event->handle = evt_handle; event->irq = irq; event->pin = pin; event->desc = desc; ret = request_threaded_irq(event->irq, NULL, handler, irqflags, "ACPI:Event", event); if (ret) { dev_err(chip->dev, "Failed to setup interrupt handler for %d\n", event->irq); goto fail_free_event; } list_add_tail(&event->node, &acpi_gpio->events); return AE_OK; fail_free_event: kfree(event); fail_unlock_irq: gpiochip_unlock_as_irq(chip, pin); fail_free_desc: gpiochip_free_own_desc(desc); return AE_ERROR; } /** * 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->dev || !chip->to_irq) return; handle = ACPI_HANDLE(chip->dev); if (!handle) return; status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio); if (ACPI_FAILURE(status)) return; INIT_LIST_HEAD(&acpi_gpio->events); acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI", acpi_gpiochip_request_interrupt, acpi_gpio); } /** * 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->dev || !chip->to_irq) return; handle = ACPI_HANDLE(chip->dev); if (!handle) return; status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio); if (ACPI_FAILURE(status)) return; list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) { struct gpio_desc *desc; free_irq(event->irq, event); desc = event->desc; if (WARN_ON(IS_ERR(desc))) continue; gpiochip_unlock_as_irq(chip, event->pin); gpiochip_free_own_desc(desc); list_del(&event->node); kfree(event); } } 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; }; static int acpi_find_gpio(struct acpi_resource *ares, void *data) { struct acpi_gpio_lookup *lookup = data; if (ares->type != ACPI_RESOURCE_TYPE_GPIO) return 1; 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[pin_index]); lookup->info.gpioint = agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT; /* * 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; } /** * 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) * @index: index of GpioIo/GpioInt resource (starting from %0) * @info: info pointer to fill in (optional) * * 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 acpi_device *adev, const char *propname, int index, struct acpi_gpio_info *info) { struct acpi_gpio_lookup lookup; struct list_head resource_list; bool active_low = false; int ret; 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); if (ret < 0) return ERR_PTR(ret); acpi_dev_free_resource_list(&resource_list); if (lookup.desc && info) { *info = lookup.info; if (active_low) info->active_low = active_low; } return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT); } 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; int pin_index = (int)address; acpi_status status; bool pull_up; 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; pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP; if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT && function == ACPI_WRITE)) { ACPI_FREE(ares); return AE_BAD_PARAMETER; } length = min(agpio->pin_table_length, (u16)(pin_index + bits)); for (i = pin_index; i < length; ++i) { unsigned 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; } } if (!found) { desc = gpiochip_request_own_desc(chip, pin, "ACPI:OpRegion"); if (IS_ERR(desc)) { status = AE_ERROR; mutex_unlock(&achip->conn_lock); goto out; } switch (agpio->io_restriction) { case ACPI_IO_RESTRICT_INPUT: gpiod_direction_input(desc); break; 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 * instead. If the pin is pulled up we * assume default to be high, otherwise * low. */ gpiod_direction_output(desc, pull_up); break; default: /* * Assume that the BIOS has configured the * direction and pull accordingly. */ break; } conn = kzalloc(sizeof(*conn), GFP_KERNEL); if (!conn) { status = AE_NO_MEMORY; gpiochip_free_own_desc(desc); mutex_unlock(&achip->conn_lock); 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, !!((1 << i) & *value)); 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->dev); 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->dev, "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->dev); 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->dev, "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); } } void acpi_gpiochip_add(struct gpio_chip *chip) { struct acpi_gpio_chip *acpi_gpio; acpi_handle handle; acpi_status status; if (!chip || !chip->dev) return; handle = ACPI_HANDLE(chip->dev); if (!handle) return; acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL); if (!acpi_gpio) { dev_err(chip->dev, "Failed to allocate memory for ACPI GPIO chip\n"); return; } acpi_gpio->chip = chip; status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio); if (ACPI_FAILURE(status)) { dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n"); kfree(acpi_gpio); return; } acpi_gpiochip_request_regions(acpi_gpio); } void acpi_gpiochip_remove(struct gpio_chip *chip) { struct acpi_gpio_chip *acpi_gpio; acpi_handle handle; acpi_status status; if (!chip || !chip->dev) return; handle = ACPI_HANDLE(chip->dev); if (!handle) return; status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio); if (ACPI_FAILURE(status)) { dev_warn(chip->dev, "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); }