gpio: better lookup method for platform GPIOs
Change the format of the platform GPIO lookup tables to make them less
confusing and improve lookup efficiency.
The previous format was a single linked-list that required to compare
the device name and function ID of every single GPIO defined for each
lookup. Switch that to a list of per-device tables, so that the lookup
can be done in two steps, omitting the GPIOs that are not relevant for a
particular device.
The matching rules are now defined as follows:
- The device name must match *exactly*, and can be NULL for GPIOs not
assigned to a particular device,
- If the function ID in the lookup table is NULL, the con_id argument of
gpiod_get() will not be used for lookup. However, if it is defined, it
must match exactly.
- The index must always match.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index c849676..44c66b2 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -141,7 +141,6 @@
* platform data.
*/
struct gpiod_lookup {
- struct list_head list;
/*
* name of the chip the GPIO belongs to
*/
@@ -151,10 +150,6 @@
*/
u16 chip_hwnum;
/*
- * name of device that can claim this GPIO
- */
- const char *dev_id;
- /*
* name of the GPIO from the device's point of view
*/
const char *con_id;
@@ -168,28 +163,32 @@
enum gpio_lookup_flags flags;
};
+struct gpiod_lookup_table {
+ struct list_head list;
+ const char *dev_id;
+ struct gpiod_lookup table[];
+};
+
/*
* Simple definition of a single GPIO under a con_id
*/
-#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _dev_id, _con_id, _flags) \
- GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, 0, _flags)
+#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \
+ GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags)
/*
* Use this macro if you need to have several GPIOs under the same con_id.
* Each GPIO needs to use a different index and can be accessed using
* gpiod_get_index()
*/
-#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, _idx, \
- _flags) \
+#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags) \
{ \
.chip_label = _chip_label, \
.chip_hwnum = _chip_hwnum, \
- .dev_id = _dev_id, \
.con_id = _con_id, \
.idx = _idx, \
.flags = _flags, \
}
-void gpiod_add_table(struct gpiod_lookup *table, size_t size);
+void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
#endif