diff options
author | Tony Lindgren <tony@atomide.com> | 2016-11-03 09:35:47 -0700 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2016-11-04 22:50:55 +0100 |
commit | 42124bc598f64f84b3335d5a058304207695b84f (patch) | |
tree | 0faea03d1084618e3799c5eda2b20aebdbe59f10 /drivers/pinctrl/devicetree.c | |
parent | b83bd893f3a04d35f5bfcf399c1034660e5b2403 (diff) | |
download | linux-42124bc598f64f84b3335d5a058304207695b84f.tar.bz2 |
pinctrl: Introduce generic #pinctrl-cells and pinctrl_parse_index_with_args
Introduce #pinctrl-cells helper binding and generic helper functions
pinctrl_count_index_with_args() and pinctrl_parse_index_with_args().
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
[Forward-declare of_phandle_args]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl/devicetree.c')
-rw-r--r-- | drivers/pinctrl/devicetree.c | 144 |
1 files changed, 144 insertions, 0 deletions
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); |