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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2015-11-11 22:45:30 +0300
committerLinus Walleij <linus.walleij@linaro.org>2015-11-19 11:24:37 +0300
commit9c3c9bc9cc980d8981f75109f3921576daf75723 (patch)
tree809b1c63c6be09bcb2d97e9032b5cc7987df6138 /drivers/gpio/gpiolib-acpi.c
parent615b8a969d0fb623a4067ad6afa9590ca5dcaf63 (diff)
downloadlinux-9c3c9bc9cc980d8981f75109f3921576daf75723.tar.xz
gpiolib: tighten up ACPI legacy gpio lookups
We should not fall back to the legacy unnamed gpio lookup style if the driver requests gpios with different names, because we'll give out the same gpio twice. Let's keep track of the names that were used for the device and only do the fallback for the first name used. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib-acpi.c')
-rw-r--r--drivers/gpio/gpiolib-acpi.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index e4620e14457f..07e571a1a377 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -925,3 +925,46 @@ 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));
+}