diff options
Diffstat (limited to 'include/linux/gpio/driver.h')
| -rw-r--r-- | include/linux/gpio/driver.h | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 783897d94be8..83e0a7e86962 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -531,11 +531,33 @@ struct gpio_chip { /** * @of_gpio_n_cells: * - * Number of cells used to form the GPIO specifier. + * Number of cells used to form the GPIO specifier. The standard is 2 + * cells: + * + * gpios = <&gpio offset flags>; + * + * some complex GPIO controllers instantiate more than one chip per + * device tree node and have 3 cells: + * + * gpios = <&gpio instance offset flags>; + * + * Legacy GPIO controllers may even have 1 cell: + * + * gpios = <&gpio offset>; */ unsigned int of_gpio_n_cells; /** + * of_node_instance_match: + * + * Determine if a chip is the right instance. Must be implemented by + * any driver using more than one gpio_chip per device tree node. + * Returns true if gc is the instance indicated by i (which is the + * first cell in the phandles for GPIO lines and gpio-ranges). + */ + bool (*of_node_instance_match)(struct gpio_chip *gc, unsigned int i); + + /** * @of_xlate: * * Callback to translate a device tree GPIO specifier into a chip- |