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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.c217
1 files changed, 172 insertions, 45 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 143a9bdba..7ab7bc3c9 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -304,7 +304,6 @@ 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);
}
@@ -389,6 +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;
};
@@ -425,6 +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
@@ -452,8 +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)
@@ -463,58 +521,64 @@ 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)
- return ERR_PTR(ret);
+ 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;
- acpi_dev_free_resource_list(&resource_list);
+ adev = to_acpi_device_node(fwnode);
+ if (adev)
+ return acpi_get_gpiod_by_index(adev, propname, index, info);
- if (lookup.desc && info) {
- *info = lookup.info;
- if (active_low)
- info->active_low = active_low;
- }
+ 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);
- return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
+ ret = acpi_gpio_resource_lookup(&lookup, info);
+ return ret ? ERR_PTR(ret) : lookup.desc;
}
/**
@@ -603,6 +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");
@@ -719,6 +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)) {
@@ -838,3 +922,46 @@ int acpi_gpio_count(struct device *dev, const char *con_id)
}
return count;
}
+
+struct acpi_crs_lookup {
+ struct list_head node;
+ struct acpi_device *adev;
+ const char *con_id;
+};
+
+static DEFINE_MUTEX(acpi_crs_lookup_lock);
+static LIST_HEAD(acpi_crs_lookup_list);
+
+bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
+{
+ struct acpi_crs_lookup *l, *lookup = NULL;
+
+ /* Never allow fallback if the device has properties */
+ if (adev->data.properties || adev->driver_gpios)
+ return false;
+
+ mutex_lock(&acpi_crs_lookup_lock);
+
+ list_for_each_entry(l, &acpi_crs_lookup_list, node) {
+ if (l->adev == adev) {
+ lookup = l;
+ break;
+ }
+ }
+
+ if (!lookup) {
+ lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
+ if (lookup) {
+ lookup->adev = adev;
+ lookup->con_id = con_id;
+ list_add_tail(&lookup->node, &acpi_crs_lookup_list);
+ }
+ }
+
+ mutex_unlock(&acpi_crs_lookup_lock);
+
+ return lookup &&
+ ((!lookup->con_id && !con_id) ||
+ (lookup->con_id && con_id &&
+ strcmp(lookup->con_id, con_id) == 0));
+}