pinctrl: core: Add generic pinctrl functions for managing groups

We can add generic helpers for function handling for cases where the pin
controller driver does not need to use static arrays.

Signed-off-by: Tony Lindgren <tony@atomide.com>
[Renamed the Kconfig item and moved things around]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

5 files changed, 243 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index add257f80d76..7e964284b2c9 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -14,6 +14,10 @@ config GENERIC_PINCTRL_GROUPS
 config PINMUX
 	bool "Support pin multiplexing controllers" if COMPILE_TEST
 
+config GENERIC_PINMUX_FUNCTIONS
+	bool
+	select PINMUX
+
 config PINCONF
 	bool "Support pin configuration controllers" if COMPILE_TEST
 
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 736149d3a33d..d311d73852a0 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1996,6 +1996,9 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
 #ifdef CONFIG_GENERIC_PINCTRL_GROUPS
 	INIT_RADIX_TREE(&pctldev->pin_group_tree, GFP_KERNEL);
 #endif
+#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
+	INIT_RADIX_TREE(&pctldev->pin_function_tree, GFP_KERNEL);
+#endif
 	INIT_LIST_HEAD(&pctldev->gpio_ranges);
 	INIT_DELAYED_WORK(&pctldev->late_init, pinctrl_late_init);
 	pctldev->dev = dev;
@@ -2076,6 +2079,7 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev)
 	mutex_lock(&pctldev->mutex);
 	/* TODO: check that no pinmuxes are still active? */
 	list_del(&pctldev->node);
+	pinmux_generic_free_functions(pctldev);
 	pinctrl_generic_free_groups(pctldev);
 	/* Destroy descriptor tree */
 	pinctrl_free_pindescs(pctldev, pctldev->desc->pins,
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index b04c59bf9701..ad812a2d7248 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -26,6 +26,8 @@ struct pinctrl_gpio_range;
  *	this radix tree
  * @pin_group_tree: optionally each pin group can be stored in this radix tree
  * @num_groups: optionally number of groups can be kept here
+ * @pin_function_tree: optionally each function can be stored in this radix tree
+ * @num_functions: optionally number of functions can be kept here
  * @gpio_ranges: a list of GPIO ranges that is handled by this pin controller,
  *	ranges are added to this list at runtime
  * @dev: the device entry for this pin controller
@@ -47,6 +49,10 @@ struct pinctrl_dev {
 	struct radix_tree_root pin_group_tree;
 	unsigned int num_groups;
 #endif
+#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
+	struct radix_tree_root pin_function_tree;
+	unsigned int num_functions;
+#endif
 	struct list_head gpio_ranges;
 	struct device *dev;
 	struct module *owner;
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index 9373146f3afc..29ad3151abec 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -682,3 +682,176 @@ void pinmux_init_device_debugfs(struct dentry *devroot,
 }
 
 #endif /* CONFIG_DEBUG_FS */
+
+#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
+
+/**
+ * pinmux_generic_get_function_count() - returns number of functions
+ * @pctldev: pin controller device
+ */
+int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev)
+{
+	return pctldev->num_functions;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_get_function_count);
+
+/**
+ * pinmux_generic_get_function_name() - returns the function name
+ * @pctldev: pin controller device
+ * @selector: function number
+ */
+const char *
+pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
+				 unsigned int selector)
+{
+	struct function_desc *function;
+
+	function = radix_tree_lookup(&pctldev->pin_function_tree,
+				     selector);
+	if (!function)
+		return NULL;
+
+	return function->name;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
+
+/**
+ * pinmux_generic_get_function_groups() - gets the function groups
+ * @pctldev: pin controller device
+ * @selector: function number
+ * @groups: array of pin groups
+ * @num_groups: number of pin groups
+ */
+int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
+				       unsigned int selector,
+				       const char * const **groups,
+				       unsigned * const num_groups)
+{
+	struct function_desc *function;
+
+	function = radix_tree_lookup(&pctldev->pin_function_tree,
+				     selector);
+	if (!function) {
+		dev_err(pctldev->dev, "%s could not find function%i\n",
+			__func__, selector);
+		return -EINVAL;
+	}
+	*groups = function->group_names;
+	*num_groups = function->num_group_names;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_get_function_groups);
+
+/**
+ * pinmux_generic_get_function() - returns a function based on the number
+ * @pctldev: pin controller device
+ * @group_selector: function number
+ */
+struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
+						  unsigned int selector)
+{
+	struct function_desc *function;
+
+	function = radix_tree_lookup(&pctldev->pin_function_tree,
+				     selector);
+	if (!function)
+		return NULL;
+
+	return function;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
+
+/**
+ * pinmux_generic_get_function_groups() - gets the function groups
+ * @pctldev: pin controller device
+ * @name: name of the function
+ * @groups: array of pin groups
+ * @num_groups: number of pin groups
+ * @data: pin controller driver specific data
+ */
+int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
+				const char *name,
+				const char **groups,
+				const unsigned int num_groups,
+				void *data)
+{
+	struct function_desc *function;
+
+	function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
+	if (!function)
+		return -ENOMEM;
+
+	function->name = name;
+	function->group_names = groups;
+	function->num_group_names = num_groups;
+	function->data = data;
+
+	radix_tree_insert(&pctldev->pin_function_tree, pctldev->num_functions,
+			  function);
+
+	pctldev->num_functions++;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
+
+/**
+ * pinmux_generic_remove_function() - removes a numbered function
+ * @pctldev: pin controller device
+ * @selector: function number
+ *
+ * Note that the caller must take care of locking.
+ */
+int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
+				   unsigned int selector)
+{
+	struct function_desc *function;
+
+	function = radix_tree_lookup(&pctldev->pin_function_tree,
+				     selector);
+	if (!function)
+		return -ENOENT;
+
+	radix_tree_delete(&pctldev->pin_function_tree, selector);
+	devm_kfree(pctldev->dev, function);
+
+	pctldev->num_functions--;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_remove_function);
+
+/**
+ * pinmux_generic_free_functions() - removes all functions
+ * @pctldev: pin controller device
+ *
+ * Note that the caller must take care of locking.
+ */
+void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
+{
+	struct radix_tree_iter iter;
+	struct function_desc *function;
+	unsigned long *indices;
+	void **slot;
+	int i = 0;
+
+	indices = devm_kzalloc(pctldev->dev, sizeof(*indices) *
+			       pctldev->num_functions, GFP_KERNEL);
+	if (!indices)
+		return;
+
+	radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
+		indices[i++] = iter.index;
+
+	for (i = 0; i < pctldev->num_functions; i++) {
+		function = radix_tree_lookup(&pctldev->pin_function_tree,
+					     indices[i]);
+		radix_tree_delete(&pctldev->pin_function_tree, indices[i]);
+		devm_kfree(pctldev->dev, function);
+	}
+
+	pctldev->num_functions = 0;
+}
+
+#endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */
diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h
index d1a98b1c9fce..248d8ea30e26 100644
--- a/drivers/pinctrl/pinmux.h
+++ b/drivers/pinctrl/pinmux.h
@@ -111,3 +111,59 @@ static inline void pinmux_init_device_debugfs(struct dentry *devroot,
 }
 
 #endif
+
+#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
+
+/**
+ * struct function_desc - generic function descriptor
+ * @name: name of the function
+ * @group_names: array of pin group names
+ * @num_group_names: number of pin group names
+ * @data: pin controller driver specific data
+ */
+struct function_desc {
+	const char *name;
+	const char **group_names;
+	int num_group_names;
+	void *data;
+};
+
+int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev);
+
+const char *
+pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
+				 unsigned int selector);
+
+int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
+				       unsigned int selector,
+				       const char * const **groups,
+				       unsigned * const num_groups);
+
+struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
+						  unsigned int selector);
+
+int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
+				const char *name,
+				const char **groups,
+				unsigned const num_groups,
+				void *data);
+
+int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
+				   unsigned int selector);
+
+static inline int
+pinmux_generic_remove_last_function(struct pinctrl_dev *pctldev)
+{
+	return pinmux_generic_remove_function(pctldev,
+					      pctldev->num_functions - 1);
+}
+
+void pinmux_generic_free_functions(struct pinctrl_dev *pctldev);
+
+#else
+
+static inline void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
+{
+}
+
+#endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */