diff options
| -rw-r--r-- | Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt | 44 | ||||
| -rw-r--r-- | drivers/pinctrl/devicetree.c | 144 | ||||
| -rw-r--r-- | drivers/pinctrl/devicetree.h | 23 |
3 files changed, 210 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt index b73c96d24f59..bf3f7b014724 100644 --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt @@ -97,6 +97,11 @@ For example: }; == Pin controller devices == +Required properties: See the pin controller driver specific documentation + +Optional properties: +#pinctrl-cells: Number of pin control cells in addition to the index within the + pin controller device instance Pin controller devices should contain the pin configuration nodes that client devices reference. @@ -119,7 +124,8 @@ For example: The contents of each of those pin configuration child nodes is defined entirely by the binding for the individual pin controller device. There -exists no common standard for this content. +exists no common standard for this content. The pinctrl framework only +provides generic helper bindings that the pin controller driver can use. The pin configuration nodes need not be direct children of the pin controller device; they may be grandchildren, for example. Whether this is legal, and @@ -156,6 +162,42 @@ state_2_node_a { pins = "mfio29", "mfio30"; }; +Optionally an altenative binding can be used if more suitable depending on the +pin controller hardware. For hardaware where there is a large number of identical +pin controller instances, naming each pin and function can easily become +unmaintainable. This is especially the case if the same controller is used for +different pins and functions depending on the SoC revision and packaging. + +For cases like this, the pin controller driver may use pinctrl-pin-array helper +binding with a hardware based index and a number of pin configuration values: + +pincontroller { + ... /* Standard DT properties for the device itself elided */ + #pinctrl-cells = <2>; + + state_0_node_a { + pinctrl-pin-array = < + 0 A_DELAY_PS(0) G_DELAY_PS(120) + 4 A_DELAY_PS(0) G_DELAY_PS(360) + ... + >; + }; + ... +}; + +Above #pinctrl-cells specifies the number of value cells in addition to the +index of the registers. This is similar to the interrupts-extended binding with +one exception. There is no need to specify the phandle for each entry as that +is already known as the defined pins are always children of the pin controller +node. Further having the phandle pointing to another pin controller would not +currently work as the pinctrl framework uses named modes to group pins for each +pin control device. + +The index for pinctrl-pin-array must relate to the hardware for the pinctrl +registers, and must not be a virtual index of pin instances. The reason for +this is to avoid mapping of the index in the dts files and the pin controller +driver as it can change. + == Generic pin configuration node content == Many data items that are represented in a pin configuration node are common diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c index 54dad89fc9bf..260908480075 100644 --- a/drivers/pinctrl/devicetree.c +++ b/drivers/pinctrl/devicetree.c @@ -253,3 +253,147 @@ err: pinctrl_dt_free_maps(p); return ret; } + +/* + * For pinctrl binding, typically #pinctrl-cells is for the pin controller + * device, so either parent or grandparent. See pinctrl-bindings.txt. + */ +static int pinctrl_find_cells_size(const struct device_node *np) +{ + const char *cells_name = "#pinctrl-cells"; + int cells_size, error; + + error = of_property_read_u32(np->parent, cells_name, &cells_size); + if (error) { + error = of_property_read_u32(np->parent->parent, + cells_name, &cells_size); + if (error) + return -ENOENT; + } + + return cells_size; +} + +/** + * pinctrl_get_list_and_count - Gets the list and it's cell size and number + * @np: pointer to device node with the property + * @list_name: property that contains the list + * @list: pointer for the list found + * @cells_size: pointer for the cell size found + * @nr_elements: pointer for the number of elements found + * + * Typically np is a single pinctrl entry containing the list. + */ +static int pinctrl_get_list_and_count(const struct device_node *np, + const char *list_name, + const __be32 **list, + int *cells_size, + int *nr_elements) +{ + int size; + + *cells_size = 0; + *nr_elements = 0; + + *list = of_get_property(np, list_name, &size); + if (!*list) + return -ENOENT; + + *cells_size = pinctrl_find_cells_size(np); + if (*cells_size < 0) + return -ENOENT; + + /* First element is always the index within the pinctrl device */ + *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); + + return 0; +} + +/** + * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry + * @np: pointer to device node with the property + * @list_name: property that contains the list + * + * Counts the number of elements in a pinctrl array consisting of an index + * within the controller and a number of u32 entries specified for each + * entry. Note that device_node is always for the parent pin controller device. + */ +int pinctrl_count_index_with_args(const struct device_node *np, + const char *list_name) +{ + const __be32 *list; + int size, nr_cells, error; + + error = pinctrl_get_list_and_count(np, list_name, &list, + &nr_cells, &size); + if (error) + return error; + + return size; +} +EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); + +/** + * pinctrl_copy_args - Populates of_phandle_args based on index + * @np: pointer to device node with the property + * @list: pointer to a list with the elements + * @index: entry within the list of elements + * @nr_cells: number of cells in the list + * @nr_elem: number of elements for each entry in the list + * @out_args: returned values + * + * Populates the of_phandle_args based on the index in the list. + */ +static int pinctrl_copy_args(const struct device_node *np, + const __be32 *list, + int index, int nr_cells, int nr_elem, + struct of_phandle_args *out_args) +{ + int i; + + memset(out_args, 0, sizeof(*out_args)); + out_args->np = (struct device_node *)np; + out_args->args_count = nr_cells + 1; + + if (index >= nr_elem) + return -EINVAL; + + list += index * (nr_cells + 1); + + for (i = 0; i < nr_cells + 1; i++) + out_args->args[i] = be32_to_cpup(list++); + + return 0; +} + +/** + * pinctrl_parse_index_with_args - Find a node pointed by index in a list + * @np: pointer to device node with the property + * @list_name: property that contains the list + * @index: index within the list + * @out_arts: entries in the list pointed by index + * + * Finds the selected element in a pinctrl array consisting of an index + * within the controller and a number of u32 entries specified for each + * entry. Note that device_node is always for the parent pin controller device. + */ +int pinctrl_parse_index_with_args(const struct device_node *np, + const char *list_name, int index, + struct of_phandle_args *out_args) +{ + const __be32 *list; + int nr_elem, nr_cells, error; + + error = pinctrl_get_list_and_count(np, list_name, &list, + &nr_cells, &nr_elem); + if (error || !nr_cells) + return error; + + error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, + out_args); + if (error) + return error; + + return 0; +} +EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); diff --git a/drivers/pinctrl/devicetree.h b/drivers/pinctrl/devicetree.h index 760bc4960f58..c2d1a5505850 100644 --- a/drivers/pinctrl/devicetree.h +++ b/drivers/pinctrl/devicetree.h @@ -16,11 +16,20 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +struct of_phandle_args; + #ifdef CONFIG_OF void pinctrl_dt_free_maps(struct pinctrl *p); int pinctrl_dt_to_map(struct pinctrl *p); +int pinctrl_count_index_with_args(const struct device_node *np, + const char *list_name); + +int pinctrl_parse_index_with_args(const struct device_node *np, + const char *list_name, int index, + struct of_phandle_args *out_args); + #else static inline int pinctrl_dt_to_map(struct pinctrl *p) @@ -32,4 +41,18 @@ static inline void pinctrl_dt_free_maps(struct pinctrl *p) { } +static inline int pinctrl_count_index_with_args(const struct device_node *np, + const char *list_name) +{ + return -ENODEV; +} + +static inline int +pinctrl_parse_index_with_args(const struct device_node *np, + const char *list_name, int index, + struct of_phandle_args *out_args) +{ + return -ENODEV; +} + #endif |