pinctrl: Introduce generic #pinctrl-cells and pinctrl_parse_index_with_args (42124bc5) · Commits · e / devices / android_kernel_oneplus_sm7250

Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt

+43 −1

Original line number	Diff line number	Diff line
		@@ -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

drivers/pinctrl/devicetree.c

+144 −0

Original line number	Diff line number	Diff line
		@@ -253,3 +253,147 @@ int pinctrl_dt_to_map(struct pinctrl *p)
		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);

drivers/pinctrl/devicetree.h

+23 −0

Original line number	Diff line number	Diff line
		@@ -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