[RFC PATCH v3 2/5] pinctrl: add dt binding support for pinmux mappings
Marek Vasut
marek.vasut at gmail.com
Tue Dec 20 14:48:38 EST 2011
> From: Dong Aisheng <dong.aisheng at linaro.org>
>
> This patch provies a common API for driver to use to register pinmux
> mappings from dts file. It is needed for dt support.
>
> Signed-off-by: Dong Aisheng <dong.aisheng at linaro.org>
> Cc: Linus Walleij <linus.walleij at linaro.org>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> Cc: Rob Herring <rob.herring at calxeda.com>
> ---
> .../devicetree/bindings/pinctrl/pinctrl.txt | 33 +++++++
> drivers/pinctrl/pinmux.c | 101
> ++++++++++++++++++++ include/linux/pinctrl/machine.h |
> 6 +
> 3 files changed, 140 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl.txt
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl.txt
> b/Documentation/devicetree/bindings/pinctrl/pinctrl.txt new file mode
> 100644
> index 0000000..a27a7ce
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl.txt
> @@ -0,0 +1,33 @@
> +The pin control subsystem
> +
> +The pin control subsystem provides a common API to support parsing pinmux
> +mappings data from device tree. Each board dts file should provide a
> device +node of which all the child nodes are the corresponding pinmux
> mappings. +
> +The required properties for pinmux mapping are:
> +- map-name: the name of this specific map entry
> +- clk-dev-name: the name of the device controlling this specific mapping
> +- funcion: a function in the driver to use for this mapping
> +
> +Optional properties:
> +- group: a certain specific pin group to activate for the function
> +- dev-name: the name of the device using this specific mapping
> +- hog-on-boot: indicate wether hog the mappings(do not need to specify
> value) +
> +Examples:
> +
> +pinmux: imx6q-sabreauto-map {
> + map-sd4 {
> + map-name = "usdhc4";
> + ctrl-dev-name = "20e0000.iomuxc";
> + function = "sd4";
> + dev-name = "219c000.usdhc";
> + };
> + ...
> +};
> +
> +Then calling pinmux_of_register_mappings() with the device node of
> +imx6q-sabreauto-map as parameter to register pinmux mappings from dts.
> +
> +Usually user can get this device node via a phandle in driver then call
> +the function to register maps. Please refer to pinctrl-imx.txt for
> example. diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
> index 432feb6..3ac3098 100644
> --- a/drivers/pinctrl/pinmux.c
> +++ b/drivers/pinctrl/pinmux.c
> @@ -20,6 +20,7 @@
> #include <linux/err.h>
> #include <linux/list.h>
> #include <linux/mutex.h>
> +#include <linux/of_device.h>
> #include <linux/spinlock.h>
> #include <linux/string.h>
> #include <linux/sysfs.h>
> @@ -410,6 +411,106 @@ int __init pinmux_register_mappings(struct pinmux_map
> const *maps, return 0;
> }
>
> +static int __devinit pinmux_of_parse_mapping(struct device_node *np,
> + struct pinmux_map *maps, unsigned id)
> +{
> + struct pinmux_map *map = &maps[id];
> + int ret = 0;
> +
> + pr_debug("parse pinmux map %d\n", id + 1);
> +
> + if (of_find_property(np, "map-name", NULL)) {
> + ret = of_property_read_string(np, "map-name", &map->name);
> + if (ret) {
> + pr_err("failed to get map-name");
> + return ret;
> + }
> + }
> +
> + if (of_find_property(np, "ctrl-dev-name", NULL)) {
> + ret = of_property_read_string(np, "ctrl-dev-name",
> + &map->ctrl_dev_name);
> + if (ret) {
> + pr_err("failed to get ctrl-dev-name");
> + return ret;
> + }
> + }
> +
> + if (of_find_property(np, "function", NULL)) {
> + ret = of_property_read_string(np, "function", &map->function);
> + if (ret) {
> + pr_err("failed to get function");
> + return ret;
> + }
> + }
> +
> + if (of_find_property(np, "group", NULL)) {
> + ret = of_property_read_string(np, "group", &map->group);
> + if (ret) {
> + pr_err("failed to get group");
> + return ret;
> + }
> + }
> +
> + if (of_find_property(np, "dev-name", NULL)) {
> + ret = of_property_read_string(np, "dev-name", &map->dev_name);
> + if (ret) {
> + pr_err("failed to get dev-name");
> + return ret;
> + }
> + }
> +
> + if (of_find_property(np, "hog-on-boot", NULL))
> + map->hog_on_boot = true;
> +
> + pr_debug("map-name: %s ctrl-dev-name: %s function: %s group: %s dev-
name:
> %s hog-on-boot: %d\n", + map->name, map->ctrl_dev_name,
map->function,
> + map->group, map->dev_name, map->hog_on_boot);
Line too long maybe?
> +
> + return 0;
> +}
> +
> +/**
> + * pinmux_of_register_mappings() - parse and register pinmux mappings from
> dt + * &np: a device node containing pinmux map properties
> + *
> + * Like pinmux_register_mappings(), the memory of pinmux maps are owned by
> + * pinctrl core and can not be freed.
> + */
> +int __devinit pinmux_of_register_mappings(struct device_node *np)
> +{
> + struct pinmux_map *maps;
> + struct device_node *child = NULL;
> + int count, i;
> + int ret;
> +
> + pr_debug("parse pinmux maps from device node %s\n", np->name);
> +
> + if (!np)
> + return -EINVAL;
> +
> + count = of_get_child_count(np);
> + if (!count) {
> + pr_err("no available pinmux maps found\n");
> + return -EINVAL;
> + }
> +
> + maps = kzalloc(count * sizeof(struct pinmux_map), GFP_KERNEL);
> + if (!maps)
> + return -ENOMEM;
> +
> + i = 0;
> + for_each_child_of_node(np, child) {
> + ret = pinmux_of_parse_mapping(child, maps, i++);
> + if (ret) {
> + pr_err("failed to parse pinmux map\n");
> + return ret;
> + }
> + }
> +
> + return pinmux_register_mappings(maps, count);
> +}
> +
> /**
> * acquire_pins() - acquire all the pins for a certain funcion on a pinmux
> * @pctldev: the device to take the pins on
> diff --git a/include/linux/pinctrl/machine.h
> b/include/linux/pinctrl/machine.h index ad430e0..74a695d 100644
> --- a/include/linux/pinctrl/machine.h
> +++ b/include/linux/pinctrl/machine.h
> @@ -78,6 +78,7 @@ struct pinmux_map {
> extern int pinmux_register_mappings(struct pinmux_map const *map,
> unsigned num_maps);
>
> +extern int pinmux_of_register_mappings(struct device_node *np);
> #else
>
> static inline int pinmux_register_mappings(struct pinmux_map const *map,
> @@ -86,5 +87,10 @@ static inline int pinmux_register_mappings(struct
> pinmux_map const *map, return 0;
> }
>
> +static inline int pinmux_of_register_mappings(struct device_node *np)
> +{
> + return 0;
> +}
> +
> #endif /* !CONFIG_PINMUX */
> #endif
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