Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1019 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
new file mode 100644
index 000000000..c705bc182
--- /dev/null
+++ b/drivers/pinctrl/pinmux.c
@@ -0,0 +1,1019 @@
+// 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/array_size.h>
+#include <linux/ctype.h>
+#include <linux/cleanup.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.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 int nfuncs;
+	unsigned int 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 int pin)
+{
+	struct pin_desc *desc = pin_desc_get(pctldev, pin);
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	const struct pinctrl_setting_mux *mux_setting;
+	bool func_is_gpio = false;
+
+	/* Can't inspect pin, assume it can be used */
+	if (!desc || !ops)
+		return true;
+
+	mux_setting = desc->mux_setting;
+
+	guard(mutex)(&desc->mux_lock);
+	if (mux_setting && ops->function_is_gpio)
+		func_is_gpio = ops->function_is_gpio(pctldev, mux_setting->func);
+
+	if (ops->strict && desc->mux_usecount && !func_is_gpio)
+		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;
+	const struct pinctrl_setting_mux *mux_setting;
+	int status = -EINVAL;
+	bool gpio_ok = false;
+
+	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;
+	}
+
+	mux_setting = desc->mux_setting;
+
+	dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
+		pin, desc->name, owner);
+
+	scoped_guard(mutex, &desc->mux_lock) {
+		if (mux_setting) {
+			if (ops->function_is_gpio)
+				gpio_ok = ops->function_is_gpio(pctldev,
+								mux_setting->func);
+		} else {
+			gpio_ok = true;
+		}
+
+		if ((!gpio_range || ops->strict) && !gpio_ok &&
+		    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) && !gpio_ok && 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)
+		module_put(pctldev->owner);
+
+out_free_pin:
+	if (status) {
+		scoped_guard(mutex, &desc->mux_lock) {
+			if (gpio_range) {
+				desc->gpio_owner = NULL;
+			} else {
+				desc->mux_usecount--;
+				if (!desc->mux_usecount)
+					desc->mux_owner = NULL;
+			}
+		}
+	}
+out:
+	if (status)
+		dev_err_probe(pctldev->dev, status, "pin-%d (%s)\n",
+			      pin, owner);
+
+	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;
+	}
+
+	scoped_guard(mutex, &desc->mux_lock) {
+		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 (gpio_range) {
+			owner = desc->gpio_owner;
+			desc->gpio_owner = NULL;
+		} else {
+			owner = desc->mux_owner;
+			desc->mux_owner = NULL;
+			desc->mux_setting = 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);
+
+	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 int pin, unsigned int 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 int 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 int 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 int nfuncs = ops->get_functions_count(pctldev);
+	unsigned int selector = 0;
+
+	/* See if this pctldev has this function */
+	while (selector < nfuncs) {
+		const char *fname = ops->get_function_name(pctldev, selector);
+
+		if (fname && !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 int 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 int *pins = NULL;
+	unsigned int 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_probe(pctldev->dev, ret,
+				"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;
+		}
+		scoped_guard(mutex, &desc->mux_lock)
+			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) {
+			scoped_guard(mutex, &desc->mux_lock)
+				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;
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	int ret = 0;
+	const unsigned int *pins = NULL;
+	unsigned int num_pins = 0;
+	int i;
+	struct pin_desc *desc;
+	bool is_equal;
+
+	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;
+		}
+		scoped_guard(mutex, &desc->mux_lock)
+			is_equal = (desc->mux_setting == &(setting->data.mux));
+
+		if (is_equal) {
+			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);
+		}
+	}
+
+	if (ops->release_mux)
+		ops->release_mux(pctldev, setting->data.mux.func,
+				 setting->data.mux.group);
+}
+
+#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 int nfuncs;
+	unsigned int 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 int 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;
+}
+DEFINE_SHOW_ATTRIBUTE(pinmux_functions);
+
+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 int 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;
+
+		scoped_guard(mutex, &desc->mux_lock) {
+			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;
+}
+DEFINE_SHOW_ATTRIBUTE(pinmux_pins);
+
+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);
+}
+
+static int pinmux_select_show(struct seq_file *s, void *unused)
+{
+	return -EPERM;
+}
+
+static ssize_t pinmux_select_write(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;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(pinmux_select);
+
+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_fops);
+}
+
+#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->func->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
+ * @ngroups: number of pin groups
+ */
+int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
+				       unsigned int selector,
+				       const char * const **groups,
+				       unsigned int * const ngroups)
+{
+	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->func->groups;
+	*ngroups = function->func->ngroups;
+
+	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
+ */
+const 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_function_is_gpio() - returns true if given function is a GPIO
+ * @pctldev: pin controller device
+ * @selector: function number
+ *
+ * Returns:
+ * True if given function is a GPIO, false otherwise.
+ */
+bool pinmux_generic_function_is_gpio(struct pinctrl_dev *pctldev,
+				     unsigned int selector)
+{
+	struct function_desc *function;
+
+	function = radix_tree_lookup(&pctldev->pin_function_tree, selector);
+	if (!function)
+		return false;
+
+	return function->func->flags & PINFUNCTION_FLAG_GPIO;
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_function_is_gpio);
+
+/**
+ * pinmux_generic_add_function() - adds a function group
+ * @pctldev: pin controller device
+ * @name: name of the function
+ * @groups: array of pin groups
+ * @ngroups: 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 ngroups,
+				void *data)
+{
+	struct pinfunction func = PINCTRL_PINFUNCTION(name, groups, ngroups);
+
+	return pinmux_generic_add_pinfunction(pctldev, &func, data);
+}
+EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
+
+/**
+ * pinmux_generic_add_pinfunction() - adds a function group
+ * @pctldev: pin controller device
+ * @func: pinfunction structure describing the function group
+ * @data: pin controller driver specific data
+ */
+int pinmux_generic_add_pinfunction(struct pinctrl_dev *pctldev,
+				   const struct pinfunction *func, void *data)
+{
+	struct function_desc *function;
+	int selector, error;
+
+	selector = pinmux_func_name_to_selector(pctldev, func->name);
+	if (selector >= 0)
+		return selector;
+
+	selector = pctldev->num_functions;
+
+	function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
+	if (!function)
+		return -ENOMEM;
+
+	/*
+	 * FIXME: It's generally a bad idea to use devres in subsystem core
+	 * code - managed interfaces are aimed at drivers - but pinctrl already
+	 * uses it all over the place so it's a larger piece of technical debt
+	 * to fix.
+	 */
+	function->func = devm_kmemdup_const(pctldev->dev, func,
+					    sizeof(*func), GFP_KERNEL);
+	if (!function->func)
+		return -ENOMEM;
+
+	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_pinfunction);
+
+/**
+ * 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 */