diff options
Diffstat (limited to 'drivers/gpio/gpiolib-acpi.c')
-rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 474 |
1 files changed, 351 insertions, 123 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 716ee984311..bf0f8b47669 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -16,16 +16,35 @@ #include <linux/export.h> #include <linux/acpi.h> #include <linux/interrupt.h> +#include <linux/mutex.h> #include "gpiolib.h" -struct acpi_gpio_evt_pin { +struct acpi_gpio_event { struct list_head node; - acpi_handle *evt_handle; + acpi_handle handle; unsigned int pin; unsigned int irq; }; +struct acpi_gpio_connection { + struct list_head node; + 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) @@ -60,176 +79,195 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin) if (pin < 0 || pin > chip->ngpio) return ERR_PTR(-EINVAL); - return gpio_to_desc(chip->base + pin); + return gpiochip_get_desc(chip, pin); } static irqreturn_t acpi_gpio_irq_handler(int irq, void *data) { - acpi_handle handle = data; + struct acpi_gpio_event *event = data; - acpi_evaluate_object(handle, NULL, NULL, NULL); + 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_evt_pin *evt_pin = data; + struct acpi_gpio_event *event = data; - acpi_execute_simple_method(evt_pin->evt_handle, NULL, evt_pin->pin); + acpi_execute_simple_method(event->handle, NULL, event->pin); return IRQ_HANDLED; } -static void acpi_gpio_evt_dh(acpi_handle handle, void *data) +static void acpi_gpio_chip_dh(acpi_handle handle, void *data) { /* The address of this function is used as a key. */ } -/** - * 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. - */ -static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) +static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares, + void *context) { - struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; - struct acpi_resource *res; + 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 list_head *evt_pins = NULL; - acpi_status status; - unsigned int pin; - int irq, ret; - char ev_name[5]; + struct acpi_gpio_event *event; + irq_handler_t handler = NULL; + struct gpio_desc *desc; + unsigned long irqflags; + int ret, pin, irq; - if (!chip->dev || !chip->to_irq) - return; + if (ares->type != ACPI_RESOURCE_TYPE_GPIO) + return AE_OK; - handle = ACPI_HANDLE(chip->dev); - if (!handle) - return; + agpio = &ares->data.gpio; + if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT) + return AE_OK; - status = acpi_get_event_resources(handle, &buf); - if (ACPI_FAILURE(status)) - return; + 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; - status = acpi_get_handle(handle, "_EVT", &evt_handle); - if (ACPI_SUCCESS(status)) { - evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL); - if (evt_pins) { - INIT_LIST_HEAD(evt_pins); - status = acpi_attach_data(handle, acpi_gpio_evt_dh, - evt_pins); - if (ACPI_FAILURE(status)) { - kfree(evt_pins); - evt_pins = NULL; - } - } + desc = gpiochip_get_desc(chip, pin); + if (IS_ERR(desc)) { + dev_err(chip->dev, "Failed to get GPIO descriptor\n"); + return AE_ERROR; } - /* - * If a GPIO interrupt has an ACPI event handler method, or _EVT is - * present, set up an interrupt handler that calls the ACPI event - * handler. - */ - for (res = buf.pointer; - res && (res->type != ACPI_RESOURCE_TYPE_END_TAG); - res = ACPI_NEXT_RESOURCE(res)) { - irq_handler_t handler = NULL; - void *data; - - if (res->type != ACPI_RESOURCE_TYPE_GPIO || - res->data.gpio.connection_type != - ACPI_RESOURCE_GPIO_TYPE_INT) - continue; + ret = gpiochip_request_own_desc(desc, "ACPI:Event"); + if (ret) { + dev_err(chip->dev, "Failed to request GPIO\n"); + return AE_ERROR; + } - pin = res->data.gpio.pin_table[0]; - if (pin > chip->ngpio) - continue; + gpiod_direction_input(desc); - irq = chip->to_irq(chip, pin); - if (irq < 0) - continue; + ret = gpiod_lock_as_irq(desc); + if (ret) { + dev_err(chip->dev, "Failed to lock GPIO as interrupt\n"); + goto fail_free_desc; + } - if (pin <= 255) { - acpi_handle ev_handle; + irq = gpiod_to_irq(desc); + if (irq < 0) { + dev_err(chip->dev, "Failed to translate GPIO to IRQ\n"); + goto fail_unlock_irq; + } - sprintf(ev_name, "_%c%02X", - res->data.gpio.triggering ? 'E' : 'L', pin); - status = acpi_get_handle(handle, ev_name, &ev_handle); - if (ACPI_SUCCESS(status)) { - handler = acpi_gpio_irq_handler; - data = ev_handle; - } + 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; } - if (!handler && evt_pins) { - struct acpi_gpio_evt_pin *evt_pin; + } - evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL); - if (!evt_pin) - continue; + event = kzalloc(sizeof(*event), GFP_KERNEL); + if (!event) + goto fail_unlock_irq; - list_add_tail(&evt_pin->node, evt_pins); - evt_pin->evt_handle = evt_handle; - evt_pin->pin = pin; - evt_pin->irq = irq; - handler = acpi_gpio_irq_handler_evt; - data = evt_pin; - } - if (!handler) - continue; + event->handle = evt_handle; + event->irq = irq; + event->pin = pin; - /* Assume BIOS sets the triggering, so no flags */ - ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler, - 0, "GPIO-signaled-ACPI-event", - data); - if (ret) - dev_err(chip->dev, - "Failed to request IRQ %d ACPI event handler\n", - irq); + 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: + gpiod_unlock_as_irq(desc); +fail_free_desc: + gpiochip_free_own_desc(desc); + + return AE_ERROR; } /** - * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts. - * @chip: gpio chip - * - * Free interrupts associated with the _EVT method for the given GPIO chip. + * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events + * @acpi_gpio: ACPI GPIO chip * - * The remaining ACPI event interrupts associated with the chip are freed - * automatically. + * 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. */ -static void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) +static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *acpi_gpio) { - acpi_handle handle; - acpi_status status; - struct list_head *evt_pins; - struct acpi_gpio_evt_pin *evt_pin, *ep; + struct gpio_chip *chip = acpi_gpio->chip; if (!chip->dev || !chip->to_irq) return; - handle = ACPI_HANDLE(chip->dev); - if (!handle) - return; + INIT_LIST_HEAD(&acpi_gpio->events); + acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI", + acpi_gpiochip_request_interrupt, acpi_gpio); +} - status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins); - if (ACPI_FAILURE(status)) +/** + * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts. + * @acpi_gpio: ACPI GPIO chip + * + * Free interrupts associated with GPIO ACPI event method for the given + * GPIO chip. + */ +static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *acpi_gpio) +{ + struct acpi_gpio_event *event, *ep; + struct gpio_chip *chip = acpi_gpio->chip; + + if (!chip->dev || !chip->to_irq) return; - list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) { - devm_free_irq(chip->dev, evt_pin->irq, evt_pin); - list_del(&evt_pin->node); - kfree(evt_pin); - } + list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) { + struct gpio_desc *desc; - acpi_detach_data(handle, acpi_gpio_evt_dh); - kfree(evt_pins); + free_irq(event->irq, event); + desc = gpiochip_get_desc(chip, event->pin); + if (WARN_ON(IS_ERR(desc))) + continue; + gpiod_unlock_as_irq(desc); + gpiochip_free_own_desc(desc); + list_del(&event->node); + kfree(event); + } } struct acpi_gpio_lookup { @@ -310,12 +348,202 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index, 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; + acpi_status status; + bool pull_up; + 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; + } + + for (i = 0; i < agpio->pin_table_length; i++) { + unsigned pin = agpio->pin_table[i]; + struct acpi_gpio_connection *conn; + struct gpio_desc *desc; + bool found; + + desc = gpiochip_get_desc(chip, pin); + if (IS_ERR(desc)) { + status = AE_ERROR; + goto out; + } + + mutex_lock(&achip->conn_lock); + + found = false; + list_for_each_entry(conn, &achip->conns, node) { + if (conn->desc == desc) { + found = true; + break; + } + } + if (!found) { + int ret; + + ret = gpiochip_request_own_desc(desc, "ACPI:OpRegion"); + if (ret) { + 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->desc = desc; + list_add_tail(&conn->node, &achip->conns); + } + + mutex_unlock(&achip->conn_lock); + + if (function == ACPI_WRITE) + gpiod_set_raw_value(desc, !!((1 << i) & *value)); + else + *value |= gpiod_get_raw_value(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) { - acpi_gpiochip_request_interrupts(chip); + struct acpi_gpio_chip *acpi_gpio; + acpi_handle handle; + acpi_status status; + + 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_interrupts(acpi_gpio); + acpi_gpiochip_request_regions(acpi_gpio); } void acpi_gpiochip_remove(struct gpio_chip *chip) { - acpi_gpiochip_free_interrupts(chip); + struct acpi_gpio_chip *acpi_gpio; + acpi_handle handle; + acpi_status status; + + 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_gpiochip_free_interrupts(acpi_gpio); + + acpi_detach_data(handle, acpi_gpio_chip_dh); + kfree(acpi_gpio); } |