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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2015-11-11 11:45:30 -0800
committerLinus Walleij <linus.walleij@linaro.org>2015-11-19 09:24:37 +0100
commit9c3c9bc9cc980d8981f75109f3921576daf75723 (patch)
tree809b1c63c6be09bcb2d97e9032b5cc7987df6138 /drivers
parent615b8a969d0fb623a4067ad6afa9590ca5dcaf63 (diff)
downloadlinux-9c3c9bc9cc980d8981f75109f3921576daf75723.tar.bz2
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')
-rw-r--r--drivers/gpio/gpiolib-acpi.c43
-rw-r--r--drivers/gpio/gpiolib.c3
-rw-r--r--drivers/gpio/gpiolib.h8
3 files changed, 54 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));
+}
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 8b35457013da..dfe09c06df49 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1869,6 +1869,9 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
/* Then from plain _CRS GPIOs */
if (IS_ERR(desc)) {
+ if (!acpi_can_fallback_to_crs(adev, con_id))
+ return ERR_PTR(-ENOENT);
+
desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
if (IS_ERR(desc))
return desc;
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 98ab08c0aa2d..2b87cbd68478 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -47,6 +47,8 @@ struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
struct acpi_gpio_info *info);
int acpi_gpio_count(struct device *dev, const char *con_id);
+
+bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
#else
static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
@@ -73,6 +75,12 @@ static inline int acpi_gpio_count(struct device *dev, const char *con_id)
{
return -ENODEV;
}
+
+static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
+ const char *con_id)
+{
+ return false;
+}
#endif
struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,