Using a string to describe a pin in the device tree can be not enough.
Some controllers may need extra information to fully describe a pin. It
concerns mainly controllers which have a per pin muxing approach which
don't fit well the notions of groups and functions.
Instead of using a pin name, a 32 bit value is used. The 16 least
significant bits are used for the pin number. Other 16 bits can be used to
store extra parameters.
Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
---
drivers/pinctrl/pinconf-generic.c | 44 ++++++++++++++++++++++++++++++---------
include/linux/pinctrl/pinctrl.h | 6 ++++++
2 files changed, 40 insertions(+), 10 deletions(-)
diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
index e63ad9f..46048cb 100644
--- a/drivers/pinctrl/pinconf-generic.c
+++ b/drivers/pinctrl/pinconf-generic.c
@@ -278,17 +278,25 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
unsigned *reserved_maps, unsigned *num_maps,
enum pinctrl_map_type type)
{
- int ret;
+ int ret, i = 0;
const char *function;
struct device *dev = pctldev->dev;
unsigned long *configs = NULL;
unsigned num_configs = 0;
- unsigned reserve, strings_count;
+ unsigned reserve, items_count, pin_id;
struct property *prop;
const char *group;
const char *subnode_target_type = "pins";
-
- ret = of_property_count_strings(np, "pins");
+ const char **items_name = NULL;
+ struct pinctrl_desc *pctldesc = pctldev->desc;
+ const __be32 *cur;
+ u32 val;
+ bool pins_prop = true;
+
+ if (pctldesc->complex_pin_desc)
+ ret = of_property_count_u32_elems(np, "pins");
+ else
+ ret = of_property_count_strings(np, "pins");
if (ret < 0) {
ret = of_property_count_strings(np, "groups");
if (ret < 0)
@@ -297,11 +305,12 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
if (type == PIN_MAP_TYPE_INVALID)
type = PIN_MAP_TYPE_CONFIGS_GROUP;
subnode_target_type = "groups";
+ pins_prop = false;
} else {
if (type == PIN_MAP_TYPE_INVALID)
type = PIN_MAP_TYPE_CONFIGS_PIN;
}
- strings_count = ret;
+ items_count = ret;
ret = of_property_read_string(np, "function", &function);
if (ret < 0) {
@@ -326,17 +335,31 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
if (num_configs)
reserve++;
- reserve *= strings_count;
+ reserve *= items_count;
ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
num_maps, reserve);
if (ret < 0)
goto exit;
- of_property_for_each_string(np, subnode_target_type, prop, group) {
+ items_name = kmalloc_array(items_count, sizeof(char *), GFP_KERNEL);
+ if (!items_name)
+ goto exit;
+ if (pctldesc->complex_pin_desc && pins_prop) {
+ of_property_for_each_u32(np, subnode_target_type, prop, cur, val) {
+ pin_id = val & PINCTRL_PIN_MASK;
+ items_name[i++] = pctldesc->pins[pin_id].name;
+ }
+ } else {
+ of_property_for_each_string(np, subnode_target_type, prop, group) {
+ items_name[i++] = group;
+ }
+ }
+
+ for (i = 0; i < items_count; i++) {
if (function) {
ret = pinctrl_utils_add_map_mux(pctldev, map,
- reserved_maps, num_maps, group,
+ reserved_maps, num_maps, items_name[i],
function);
if (ret < 0)
goto exit;
@@ -344,8 +367,8 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
if (num_configs) {
ret = pinctrl_utils_add_map_configs(pctldev, map,
- reserved_maps, num_maps, group, configs,
- num_configs, type);
+ reserved_maps, num_maps, items_name[i],
+ configs, num_configs, type);
if (ret < 0)
goto exit;
}
@@ -353,6 +376,7 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
ret = 0;
exit:
+ kfree(items_name);
kfree(configs);
return ret;
}
diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
index 66e4697..116c059 100644
--- a/include/linux/pinctrl/pinctrl.h
+++ b/include/linux/pinctrl/pinctrl.h
@@ -45,6 +45,8 @@ struct pinctrl_pin_desc {
#define PINCTRL_PIN(a, b) { .number = a, .name = b }
#define PINCTRL_PIN_ANON(a) { .number = a }
+#define PINCTRL_PIN_MASK 0xffff
+
/**
* struct pinctrl_gpio_range - each pin controller can provide subranges of
* the GPIO number space to be handled by the controller
@@ -112,6 +114,9 @@ struct pinctrl_ops {
* this pin controller
* @npins: number of descriptors in the array, usually just ARRAY_SIZE()
* of the pins field above
+ * @complex_pin_desc: some pin controllers need more information than the pin
+ * name. In this case, pins property uses u32 instead of string. In this
+ * value there is the pin number plus optional parameters.
* @pctlops: pin control operation vtable, to support global concepts like
* grouping of pins, this is optional.
* @pmxops: pinmux operations vtable, if you support pinmuxing in your driver
@@ -129,6 +134,7 @@ struct pinctrl_desc {
const char *name;
struct pinctrl_pin_desc const *pins;
unsigned int npins;
+ bool complex_pin_desc;
const struct pinctrl_ops *pctlops;
const struct pinmux_ops *pmxops;
const struct pinconf_ops *confops;
--
2.2.0
--
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