Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 950 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
new file mode 100644
index 0000000000..2a180a5d64
--- /dev/null
+++ b/drivers/pinctrl/pinmux.c
@@ -0,0 +1,950 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Core driver for the pin muxing portions of the pin control subsystem
+ *
+ * Copyright (C) 2011-2012 ST-Ericsson SA
+ * Written on behalf of Linaro for ST-Ericsson
+ * Based on bits of regulator core, gpio core and clk core
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
+ */
+#define pr_fmt(fmt) "pinmux core: " fmt
+
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/radix-tree.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+
+#include "core.h"
+#include "pinmux.h"
+
+int pinmux_check_ops(struct pinctrl_dev *pctldev)
+{
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	unsigned nfuncs;
+	unsigned selector = 0;
+
+	/* Check that we implement required operations */
+	if (!ops ||
+	    !ops->get_functions_count ||
+	    !ops->get_function_name ||
+	    !ops->get_function_groups ||
+	    !ops->set_mux) {
+		dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
+		return -EINVAL;
+	}
+	/* Check that all functions registered have names */
+	nfuncs = ops->get_functions_count(pctldev);
+	while (selector < nfuncs) {
+		const char *fname = ops->get_function_name(pctldev,
+							   selector);
+		if (!fname) {
+			dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
+				selector);
+			return -EINVAL;
+		}
+		selector++;
+	}
+
+	return 0;
+}
+
+int pinmux_validate_map(const struct pinctrl_map *map, int i)
+{
+	if (!map->data.mux.function) {
+		pr_err("failed to register map %s (%d): no function given\n",
+		       map->name, i);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * pinmux_can_be_used_for_gpio() - check if a specific pin
+ *	is either muxed to a different function or used as gpio.
+ *
+ * @pctldev: the associated pin controller device
+ * @pin: the pin number in the global pin space
+ *
+ * Controllers not defined as strict will always return true,
+ * menaning that the gpio can be used.
+ */
+bool pinmux_can_be_used_for_gpio(struct pinctrl_dev *pctldev, unsigned pin)
+{
+	struct pin_desc *desc = pin_desc_get(pctldev, pin);
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+
+	/* Can't inspect pin, assume it can be used */
+	if (!desc || !ops)
+		return true;
+
+	if (ops->strict && desc->mux_usecount)
+		return false;
+
+	return !(ops->strict && !!desc->gpio_owner);
+}
+
+/**
+ * pin_request() - request a single pin to be muxed in, typically for GPIO
+ * @pctldev: the associated pin controller device
+ * @pin: the pin number in the global pin space
+ * @owner: a representation of the owner of this pin; typically the device
+ *	name that controls its mux function, or the requested GPIO name
+ * @gpio_range: the range matching the GPIO pin if this is a request for a
+ *	single GPIO pin
+ */
+static int pin_request(struct pinctrl_dev *pctldev,
+		       int pin, const char *owner,
+		       struct pinctrl_gpio_range *gpio_range)
+{
+	struct pin_desc *desc;
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	int status = -EINVAL;
+
+	desc = pin_desc_get(pctldev, pin);
+	if (desc == NULL) {
+		dev_err(pctldev->dev,
+			"pin %d is not registered so it cannot be requested\n",
+			pin);
+		goto out;
+	}
+
+	dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
+		pin, desc->name, owner);
+
+	if ((!gpio_range || ops->strict) &&
+	    desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
+		dev_err(pctldev->dev,
+			"pin %s already requested by %s; cannot claim for %s\n",
+			desc->name, desc->mux_owner, owner);
+		goto out;
+	}
+
+	if ((gpio_range || ops->strict) && desc->gpio_owner) {
+		dev_err(pctldev->dev,
+			"pin %s already requested by %s; cannot claim for %s\n",
+			desc->name, desc->gpio_owner, owner);
+		goto out;
+	}
+
+	if (gpio_range) {
+		desc->gpio_owner = owner;
+	} else {
+		desc->mux_usecount++;
+		if (desc->mux_usecount > 1)
+			return 0;
+
+		desc->mux_owner = owner;
+	}
+
+	/* Let each pin increase references to this module */
+	if (!try_module_get(pctldev->owner)) {
+		dev_err(pctldev->dev,
+			"could not increase module refcount for pin %d\n",
+			pin);
+		status = -EINVAL;
+		goto out_free_pin;
+	}
+
+	/*
+	 * If there is no kind of request function for the pin we just assume
+	 * we got it by default and proceed.
+	 */
+	if (gpio_range && ops->gpio_request_enable)
+		/* This requests and enables a single GPIO pin */
+		status = ops->gpio_request_enable(pctldev, gpio_range, pin);
+	else if (ops->request)
+		status = ops->request(pctldev, pin);
+	else
+		status = 0;
+
+	if (status) {
+		dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
+		module_put(pctldev->owner);
+	}
+
+out_free_pin:
+	if (status) {
+		if (gpio_range) {
+			desc->gpio_owner = NULL;
+		} else {
+			desc->mux_usecount--;
+			if (!desc->mux_usecount)
+				desc->mux_owner = NULL;
+		}
+	}
+out:
+	if (status)
+		dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
+			pin, owner, status);
+
+	return status;
+}
+
+/**
+ * pin_free() - release a single muxed in pin so something else can be muxed
+ * @pctldev: pin controller device handling this pin
+ * @pin: the pin to free
+ * @gpio_range: the range matching the GPIO pin if this is a request for a
+ *	single GPIO pin
+ *
+ * This function returns a pointer to the previous owner. This is used
+ * for callers that dynamically allocate an owner name so it can be freed
+ * once the pin is free. This is done for GPIO request functions.
+ */
+static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
+			    struct pinctrl_gpio_range *gpio_range)
+{
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	struct pin_desc *desc;
+	const char *owner;
+
+	desc = pin_desc_get(pctldev, pin);
+	if (desc == NULL) {
+		dev_err(pctldev->dev,
+			"pin is not registered so it cannot be freed\n");
+		return NULL;
+	}
+
+	if (!gpio_range) {
+		/*
+		 * A pin should not be freed more times than allocated.
+		 */
+		if (WARN_ON(!desc->mux_usecount))
+			return NULL;
+		desc->mux_usecount--;
+		if (desc->mux_usecount)
+			return NULL;
+	}
+
+	/*
+	 * If there is no kind of request function for the pin we just assume
+	 * we got it by default and proceed.
+	 */
+	if (gpio_range && ops->gpio_disable_free)
+		ops->gpio_disable_free(pctldev, gpio_range, pin);
+	else if (ops->free)
+		ops->free(pctldev, pin);
+
+	if (gpio_range) {
+		owner = desc->gpio_owner;
+		desc->gpio_owner = NULL;
+	} else {
+		owner = desc->mux_owner;
+		desc->mux_owner = NULL;
+		desc->mux_setting = NULL;
+	}
+
+	module_put(pctldev->owner);
+
+	return owner;
+}
+
+/**
+ * pinmux_request_gpio() - request pinmuxing for a GPIO pin
+ * @pctldev: pin controller device affected
+ * @pin: the pin to mux in for GPIO
+ * @range: the applicable GPIO range
+ * @gpio: number of requested GPIO
+ */
+int pinmux_request_gpio(struct pinctrl_dev *pctldev,
+			struct pinctrl_gpio_range *range,
+			unsigned pin, unsigned gpio)
+{
+	const char *owner;
+	int ret;
+
+	/* Conjure some name stating what chip and pin this is taken by */
+	owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
+	if (!owner)
+		return -ENOMEM;
+
+	ret = pin_request(pctldev, pin, owner, range);
+	if (ret < 0)
+		kfree(owner);
+
+	return ret;
+}
+
+/**
+ * pinmux_free_gpio() - release a pin from GPIO muxing
+ * @pctldev: the pin controller device for the pin
+ * @pin: the affected currently GPIO-muxed in pin
+ * @range: applicable GPIO range
+ */
+void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
+		      struct pinctrl_gpio_range *range)
+{
+	const char *owner;
+
+	owner = pin_free(pctldev, pin, range);
+	kfree(owner);
+}
+
+/**
+ * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
+ * @pctldev: the pin controller handling this pin
+ * @range: applicable GPIO range
+ * @pin: the affected GPIO pin in this controller
+ * @input: true if we set the pin as input, false for output
+ */
+int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
+			  struct pinctrl_gpio_range *range,
+			  unsigned pin, bool input)
+{
+	const struct pinmux_ops *ops;
+	int ret;
+
+	ops = pctldev->desc->pmxops;
+
+	if (ops->gpio_set_direction)
+		ret = ops->gpio_set_direction(pctldev, range, pin, input);
+	else
+		ret = 0;
+
+	return ret;
+}
+
+static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
+					const char *function)
+{
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	unsigned nfuncs = ops->get_functions_count(pctldev);
+	unsigned selector = 0;
+
+	/* See if this pctldev has this function */
+	while (selector < nfuncs) {
+		const char *fname = ops->get_function_name(pctldev, selector);
+
+		if (!strcmp(function, fname))
+			return selector;
+
+		selector++;
+	}
+
+	return -EINVAL;
+}
+
+int pinmux_map_to_setting(const struct pinctrl_map *map,
+			  struct pinctrl_setting *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	char const * const *groups;
+	unsigned num_groups;
+	int ret;
+	const char *group;
+
+	if (!pmxops) {
+		dev_err(pctldev->dev, "does not support mux function\n");
+		return -EINVAL;
+	}
+
+	ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "invalid function %s in map table\n",
+			map->data.mux.function);
+		return ret;
+	}
+	setting->data.mux.func = ret;
+
+	ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
+					  &groups, &num_groups);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "can't query groups for function %s\n",
+			map->data.mux.function);
+		return ret;
+	}
+	if (!num_groups) {
+		dev_err(pctldev->dev,
+			"function %s can't be selected on any group\n",
+			map->data.mux.function);
+		return -EINVAL;
+	}
+	if (map->data.mux.group) {
+		group = map->data.mux.group;
+		ret = match_string(groups, num_groups, group);
+		if (ret < 0) {
+			dev_err(pctldev->dev,
+				"invalid group \"%s\" for function \"%s\"\n",
+				group, map->data.mux.function);
+			return ret;
+		}
+	} else {
+		group = groups[0];
+	}
+
+	ret = pinctrl_get_group_selector(pctldev, group);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "invalid group %s in map table\n",
+			map->data.mux.group);
+		return ret;
+	}
+	setting->data.mux.group = ret;
+
+	return 0;
+}
+
+void pinmux_free_setting(const struct pinctrl_setting *setting)
+{
+	/* This function is currently unused */
+}
+
+int pinmux_enable_setting(const struct pinctrl_setting *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	int ret = 0;
+	const unsigned *pins = NULL;
+	unsigned num_pins = 0;
+	int i;
+	struct pin_desc *desc;
+
+	if (pctlops->get_group_pins)
+		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
+					      &pins, &num_pins);
+
+	if (ret) {
+		const char *gname;
+
+		/* errors only affect debug data, so just warn */
+		gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+		dev_warn(pctldev->dev,
+			 "could not get pins for group %s\n",
+			 gname);
+		num_pins = 0;
+	}
+
+	/* Try to allocate all pins in this group, one by one */
+	for (i = 0; i < num_pins; i++) {
+		ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
+		if (ret) {
+			const char *gname;
+			const char *pname;
+
+			desc = pin_desc_get(pctldev, pins[i]);
+			pname = desc ? desc->name : "non-existing";
+			gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+			dev_err(pctldev->dev,
+				"could not request pin %d (%s) from group %s "
+				" on device %s\n",
+				pins[i], pname, gname,
+				pinctrl_dev_get_name(pctldev));
+			goto err_pin_request;
+		}
+	}
+
+	/* Now that we have acquired the pins, encode the mux setting */
+	for (i = 0; i < num_pins; i++) {
+		desc = pin_desc_get(pctldev, pins[i]);
+		if (desc == NULL) {
+			dev_warn(pctldev->dev,
+				 "could not get pin desc for pin %d\n",
+				 pins[i]);
+			continue;
+		}
+		desc->mux_setting = &(setting->data.mux);
+	}
+
+	ret = ops->set_mux(pctldev, setting->data.mux.func,
+			   setting->data.mux.group);
+
+	if (ret)
+		goto err_set_mux;
+
+	return 0;
+
+err_set_mux:
+	for (i = 0; i < num_pins; i++) {
+		desc = pin_desc_get(pctldev, pins[i]);
+		if (desc)
+			desc->mux_setting = NULL;
+	}
+err_pin_request:
+	/* On error release all taken pins */
+	while (--i >= 0)
+		pin_free(pctldev, pins[i], NULL);
+
+	return ret;
+}
+
+void pinmux_disable_setting(const struct pinctrl_setting *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	int ret = 0;
+	const unsigned *pins = NULL;
+	unsigned num_pins = 0;
+	int i;
+	struct pin_desc *desc;
+
+	if (pctlops->get_group_pins)
+		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
+					      &pins, &num_pins);
+	if (ret) {
+		const char *gname;
+
+		/* errors only affect debug data, so just warn */
+		gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+		dev_warn(pctldev->dev,
+			 "could not get pins for group %s\n",
+			 gname);
+		num_pins = 0;
+	}
+
+	/* Flag the descs that no setting is active */
+	for (i = 0; i < num_pins; i++) {
+		desc = pin_desc_get(pctldev, pins[i]);
+		if (desc == NULL) {
+			dev_warn(pctldev->dev,
+				 "could not get pin desc for pin %d\n",
+				 pins[i]);
+			continue;
+		}
+		if (desc->mux_setting == &(setting->data.mux)) {
+			pin_free(pctldev, pins[i], NULL);
+		} else {
+			const char *gname;
+
+			gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+			dev_warn(pctldev->dev,
+				 "not freeing pin %d (%s) as part of "
+				 "deactivating group %s - it is already "
+				 "used for some other setting",
+				 pins[i], desc->name, gname);
+		}
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+/* Called from pincontrol core */
+static int pinmux_functions_show(struct seq_file *s, void *what)
+{
+	struct pinctrl_dev *pctldev = s->private;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	unsigned nfuncs;
+	unsigned func_selector = 0;
+
+	if (!pmxops)
+		return 0;
+
+	mutex_lock(&pctldev->mutex);
+	nfuncs = pmxops->get_functions_count(pctldev);
+	while (func_selector < nfuncs) {
+		const char *func = pmxops->get_function_name(pctldev,
+							  func_selector);
+		const char * const *groups;
+		unsigned num_groups;
+		int ret;
+		int i;
+
+		ret = pmxops->get_function_groups(pctldev, func_selector,
+						  &groups, &num_groups);
+		if (ret) {
+			seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
+				   func);
+			func_selector++;
+			continue;
+		}
+
+		seq_printf(s, "function %d: %s, groups = [ ", func_selector, func);
+		for (i = 0; i < num_groups; i++)
+			seq_printf(s, "%s ", groups[i]);
+		seq_puts(s, "]\n");
+
+		func_selector++;
+	}
+
+	mutex_unlock(&pctldev->mutex);
+
+	return 0;
+}
+
+static int pinmux_pins_show(struct seq_file *s, void *what)
+{
+	struct pinctrl_dev *pctldev = s->private;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	unsigned i, pin;
+
+	if (!pmxops)
+		return 0;
+
+	seq_puts(s, "Pinmux settings per pin\n");
+	if (pmxops->strict)
+		seq_puts(s,
+		 "Format: pin (name): mux_owner|gpio_owner (strict) hog?\n");
+	else
+		seq_puts(s,
+		"Format: pin (name): mux_owner gpio_owner hog?\n");
+
+	mutex_lock(&pctldev->mutex);
+
+	/* The pin number can be retrived from the pin controller descriptor */
+	for (i = 0; i < pctldev->desc->npins; i++) {
+		struct pin_desc *desc;
+		bool is_hog = false;
+
+		pin = pctldev->desc->pins[i].number;
+		desc = pin_desc_get(pctldev, pin);
+		/* Skip if we cannot search the pin */
+		if (desc == NULL)
+			continue;
+
+		if (desc->mux_owner &&
+		    !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
+			is_hog = true;
+
+		if (pmxops->strict) {
+			if (desc->mux_owner)
+				seq_printf(s, "pin %d (%s): device %s%s",
+					   pin, desc->name, desc->mux_owner,
+					   is_hog ? " (HOG)" : "");
+			else if (desc->gpio_owner)
+				seq_printf(s, "pin %d (%s): GPIO %s",
+					   pin, desc->name, desc->gpio_owner);
+			else
+				seq_printf(s, "pin %d (%s): UNCLAIMED",
+					   pin, desc->name);
+		} else {
+			/* For non-strict controllers */
+			seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name,
+				   desc->mux_owner ? desc->mux_owner
+				   : "(MUX UNCLAIMED)",
+				   desc->gpio_owner ? desc->gpio_owner
+				   : "(GPIO UNCLAIMED)",
+				   is_hog ? " (HOG)" : "");
+		}
+
+		/* If mux: print function+group claiming the pin */
+		if (desc->mux_setting)
+			seq_printf(s, " function %s group %s\n",
+				   pmxops->get_function_name(pctldev,
+					desc->mux_setting->func),
+				   pctlops->get_group_name(pctldev,
+					desc->mux_setting->group));
+		else
+			seq_putc(s, '\n');
+	}
+
+	mutex_unlock(&pctldev->mutex);
+
+	return 0;
+}
+
+void pinmux_show_map(struct seq_file *s, const struct pinctrl_map *map)
+{
+	seq_printf(s, "group %s\nfunction %s\n",
+		map->data.mux.group ? map->data.mux.group : "(default)",
+		map->data.mux.function);
+}
+
+void pinmux_show_setting(struct seq_file *s,
+			 const struct pinctrl_setting *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+
+	seq_printf(s, "group: %s (%u) function: %s (%u)\n",
+		   pctlops->get_group_name(pctldev, setting->data.mux.group),
+		   setting->data.mux.group,
+		   pmxops->get_function_name(pctldev, setting->data.mux.func),
+		   setting->data.mux.func);
+}
+
+DEFINE_SHOW_ATTRIBUTE(pinmux_functions);
+DEFINE_SHOW_ATTRIBUTE(pinmux_pins);
+
+static ssize_t pinmux_select(struct file *file, const char __user *user_buf,
+				   size_t len, loff_t *ppos)
+{
+	struct seq_file *sfile = file->private_data;
+	struct pinctrl_dev *pctldev = sfile->private;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	const char *const *groups;
+	char *buf, *gname, *fname;
+	unsigned int num_groups;
+	int fsel, gsel, ret;
+
+	buf = memdup_user_nul(user_buf, len);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	/* remove leading and trailing spaces of input buffer */
+	gname = strstrip(buf);
+	if (*gname == '\0') {
+		ret = -EINVAL;
+		goto exit_free_buf;
+	}
+
+	/* find a separator which is a spacelike character */
+	for (fname = gname; !isspace(*fname); fname++) {
+		if (*fname == '\0') {
+			ret = -EINVAL;
+			goto exit_free_buf;
+		}
+	}
+	*fname = '\0';
+
+	/* drop extra spaces between function and group names */
+	fname = skip_spaces(fname + 1);
+	if (*fname == '\0') {
+		ret = -EINVAL;
+		goto exit_free_buf;
+	}
+
+	ret = pinmux_func_name_to_selector(pctldev, fname);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "invalid function %s in map table\n", fname);
+		goto exit_free_buf;
+	}
+	fsel = ret;
+
+	ret = pmxops->get_function_groups(pctldev, fsel, &groups, &num_groups);
+	if (ret) {
+		dev_err(pctldev->dev, "no groups for function %d (%s)", fsel, fname);
+		goto exit_free_buf;
+	}
+
+	ret = match_string(groups, num_groups, gname);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "invalid group %s", gname);
+		goto exit_free_buf;
+	}
+
+	ret = pinctrl_get_group_selector(pctldev, gname);
+	if (ret < 0)
+		goto exit_free_buf;
+	gsel = ret;
+
+	ret = pmxops->set_mux(pctldev, fsel, gsel);
+	if (ret) {
+		dev_err(pctldev->dev, "set_mux() failed: %d", ret);
+		goto exit_free_buf;
+	}
+	ret = len;
+
+exit_free_buf:
+	kfree(buf);
+
+	return ret;
+}
+
+static int pinmux_select_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, NULL, inode->i_private);
+}
+
+static const struct file_operations pinmux_select_ops = {
+	.owner = THIS_MODULE,
+	.open = pinmux_select_open,
+	.write = pinmux_select,
+	.llseek = no_llseek,
+	.release = single_release,
+};
+
+void pinmux_init_device_debugfs(struct dentry *devroot,
+			 struct pinctrl_dev *pctldev)
+{
+	debugfs_create_file("pinmux-functions", 0444,
+			    devroot, pctldev, &pinmux_functions_fops);
+	debugfs_create_file("pinmux-pins", 0444,
+			    devroot, pctldev, &pinmux_pins_fops);
+	debugfs_create_file("pinmux-select", 0200,
+			    devroot, pctldev, &pinmux_select_ops);
+}
+
+#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
+ * @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_add_function() - adds a function group
+ * @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 * const *groups,
+				const unsigned int num_groups,
+				void *data)
+{
+	struct function_desc *function;
+	int selector, error;
+
+	if (!name)
+		return -EINVAL;
+
+	selector = pinmux_func_name_to_selector(pctldev, name);
+	if (selector >= 0)
+		return selector;
+
+	selector = pctldev->num_functions;
+
+	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;
+
+	error = radix_tree_insert(&pctldev->pin_function_tree, selector, function);
+	if (error)
+		return error;
+
+	pctldev->num_functions++;
+
+	return selector;
+}
+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. The pinctrl
+ * functions are allocated with devm_kzalloc() so no need to free
+ * them here.
+ */
+void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
+{
+	struct radix_tree_iter iter;
+	void __rcu **slot;
+
+	radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
+		radix_tree_delete(&pctldev->pin_function_tree, iter.index);
+
+	pctldev->num_functions = 0;
+}
+
+#endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */