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path: root/drivers/gpio/gpiolib-acpi.c
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Diffstat (limited to 'drivers/gpio/gpiolib-acpi.c')
-rw-r--r--drivers/gpio/gpiolib-acpi.c474
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);
}