pinctrl: move subsystem mutex to pinctrl_dev struct

This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.

Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().

For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
	- pinctrl_get()/pinctrl_put()
	- pinctrl_register_maps()

So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.

Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.

Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().

Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
  is located inside pinctrl_select_state(). When parsing
  the state->setting list, take the per-pin-controller driver
  lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
  in all functions which parse or modify pictrldev_list.
  (Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
  pinctrl/core.c in order to protect pinctrldev_list.
  (Patrice).
- Sink mutex:es into some functions and remove some _locked
  variants down to where the lists are actually accessed to
  make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
  and pinctrl_select_state() - no relevant mutex was taken
  and it was unclear what this was protecting against. (Linus)

Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

5 files changed, 176 insertions, 164 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 8b832ce6a8e3..c3d222ed39a2 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -40,11 +40,17 @@
 
 static bool pinctrl_dummy_state;
 
-/* Mutex taken by all entry points */
-DEFINE_MUTEX(pinctrl_mutex);
+/* Mutex taken to protect pinctrl_list */
+DEFINE_MUTEX(pinctrl_list_mutex);
+
+/* Mutex taken to protect pinctrl_maps */
+DEFINE_MUTEX(pinctrl_maps_mutex);
+
+/* Mutex taken to protect pinctrldev_list */
+DEFINE_MUTEX(pinctrldev_list_mutex);
 
 /* Global list of pin control devices (struct pinctrl_dev) */
-LIST_HEAD(pinctrldev_list);
+static LIST_HEAD(pinctrldev_list);
 
 /* List of pin controller handles (struct pinctrl) */
 static LIST_HEAD(pinctrl_list);
@@ -111,6 +117,23 @@ struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *devname)
         return found ? pctldev : NULL;
 }
 
+struct pinctrl_dev *get_pinctrl_dev_from_of_node(struct device_node *np)
+{
+        struct pinctrl_dev *pctldev;
+
+        mutex_lock(&pinctrldev_list_mutex);
+
+        list_for_each_entry(pctldev, &pinctrldev_list, node)
+                if (pctldev->dev->of_node == np) {
+                        mutex_unlock(&pinctrldev_list_mutex);
+                        return pctldev;
+                }
+
+        mutex_lock(&pinctrldev_list_mutex);
+
+        return NULL;
+}
+
 /**
  * pin_get_from_name() - look up a pin number from a name
  * @pctldev: the pin control device to lookup the pin on
@@ -170,9 +193,9 @@ bool pin_is_valid(struct pinctrl_dev *pctldev, int pin)
         if (pin < 0)
                 return false;
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
         pindesc = pin_desc_get(pctldev, pin);
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return pindesc != NULL;
 }
@@ -269,15 +292,17 @@ pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio)
 {
         struct pinctrl_gpio_range *range = NULL;
 
+        mutex_lock(&pctldev->mutex);
         /* Loop over the ranges */
         list_for_each_entry(range, &pctldev->gpio_ranges, node) {
                 /* Check if we're in the valid range */
                 if (gpio >= range->base &&
                     gpio < range->base + range->npins) {
+                        mutex_unlock(&pctldev->mutex);
                         return range;
                 }
         }
-
+        mutex_unlock(&pctldev->mutex);
         return NULL;
 }
 
@@ -361,9 +386,9 @@ static int pinctrl_get_device_gpio_range(unsigned gpio,
 void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev,
                             struct pinctrl_gpio_range *range)
 {
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
         list_add_tail(&range->node, &pctldev->gpio_ranges);
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 }
 EXPORT_SYMBOL_GPL(pinctrl_add_gpio_range);
 
@@ -381,17 +406,25 @@ EXPORT_SYMBOL_GPL(pinctrl_add_gpio_ranges);
 struct pinctrl_dev *pinctrl_find_and_add_gpio_range(const char *devname,
                 struct pinctrl_gpio_range *range)
 {
-        struct pinctrl_dev *pctldev = get_pinctrl_dev_from_devname(devname);
+        struct pinctrl_dev *pctldev;
+
+        mutex_lock(&pinctrldev_list_mutex);
+
+        pctldev = get_pinctrl_dev_from_devname(devname);
 
         /*
          * If we can't find this device, let's assume that is because
          * it has not probed yet, so the driver trying to register this
          * range need to defer probing.
          */
-        if (!pctldev)
+        if (!pctldev) {
+                mutex_unlock(&pinctrldev_list_mutex);
                 return ERR_PTR(-EPROBE_DEFER);
-
+        }
         pinctrl_add_gpio_range(pctldev, range);
+
+        mutex_unlock(&pinctrldev_list_mutex);
+
         return pctldev;
 }
 EXPORT_SYMBOL_GPL(pinctrl_find_and_add_gpio_range);
@@ -407,14 +440,17 @@ pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev,
 {
         struct pinctrl_gpio_range *range = NULL;
 
+        mutex_lock(&pctldev->mutex);
         /* Loop over the ranges */
         list_for_each_entry(range, &pctldev->gpio_ranges, node) {
                 /* Check if we're in the valid range */
                 if (pin >= range->pin_base &&
                     pin < range->pin_base + range->npins) {
+                        mutex_unlock(&pctldev->mutex);
                         return range;
                 }
         }
+        mutex_unlock(&pctldev->mutex);
 
         return NULL;
 }
@@ -428,9 +464,9 @@ EXPORT_SYMBOL_GPL(pinctrl_find_gpio_range_from_pin);
 void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev,
                                struct pinctrl_gpio_range *range)
 {
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
         list_del(&range->node);
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 }
 EXPORT_SYMBOL_GPL(pinctrl_remove_gpio_range);
 
@@ -481,13 +517,13 @@ int pinctrl_request_gpio(unsigned gpio)
         int ret;
         int pin;
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pinctrldev_list_mutex);
 
         ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
         if (ret) {
                 if (pinctrl_ready_for_gpio_range(gpio))
                         ret = 0;
-                mutex_unlock(&pinctrl_mutex);
+                mutex_unlock(&pinctrldev_list_mutex);
                 return ret;
         }
 
@@ -496,7 +532,7 @@ int pinctrl_request_gpio(unsigned gpio)
 
         ret = pinmux_request_gpio(pctldev, range, pin, gpio);
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pinctrldev_list_mutex);
         return ret;
 }
 EXPORT_SYMBOL_GPL(pinctrl_request_gpio);
@@ -516,20 +552,22 @@ void pinctrl_free_gpio(unsigned gpio)
         int ret;
         int pin;
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pinctrldev_list_mutex);
 
         ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
         if (ret) {
-                mutex_unlock(&pinctrl_mutex);
+                mutex_unlock(&pinctrldev_list_mutex);
                 return;
         }
+        mutex_lock(&pctldev->mutex);
 
         /* Convert to the pin controllers number space */
         pin = gpio - range->base + range->pin_base;
 
         pinmux_free_gpio(pctldev, pin, range);
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
+        mutex_unlock(&pinctrldev_list_mutex);
 }
 EXPORT_SYMBOL_GPL(pinctrl_free_gpio);
 
@@ -540,14 +578,24 @@ static int pinctrl_gpio_direction(unsigned gpio, bool input)
         int ret;
         int pin;
 
+        mutex_lock(&pinctrldev_list_mutex);
+
         ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
-        if (ret)
+        if (ret) {
+                mutex_unlock(&pinctrldev_list_mutex);
                 return ret;
+        }
+
+        mutex_lock(&pctldev->mutex);
 
         /* Convert to the pin controllers number space */
         pin = gpio - range->base + range->pin_base;
+        ret = pinmux_gpio_direction(pctldev, range, pin, input);
+
+        mutex_unlock(&pctldev->mutex);
+        mutex_unlock(&pinctrldev_list_mutex);
 
-        return pinmux_gpio_direction(pctldev, range, pin, input);
+        return ret;
 }
 
 /**
@@ -560,11 +608,7 @@ static int pinctrl_gpio_direction(unsigned gpio, bool input)
  */
 int pinctrl_gpio_direction_input(unsigned gpio)
 {
-        int ret;
-        mutex_lock(&pinctrl_mutex);
-        ret = pinctrl_gpio_direction(gpio, true);
-        mutex_unlock(&pinctrl_mutex);
-        return ret;
+        return pinctrl_gpio_direction(gpio, true);
 }
 EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_input);
 
@@ -578,11 +622,7 @@ EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_input);
  */
 int pinctrl_gpio_direction_output(unsigned gpio)
 {
-        int ret;
-        mutex_lock(&pinctrl_mutex);
-        ret = pinctrl_gpio_direction(gpio, false);
-        mutex_unlock(&pinctrl_mutex);
-        return ret;
+        return pinctrl_gpio_direction(gpio, false);
 }
 EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_output);
 
@@ -685,14 +725,18 @@ static struct pinctrl *find_pinctrl(struct device *dev)
 {
         struct pinctrl *p;
 
+        mutex_lock(&pinctrl_list_mutex);
         list_for_each_entry(p, &pinctrl_list, node)
-                if (p->dev == dev)
+                if (p->dev == dev) {
+                        mutex_unlock(&pinctrl_list_mutex);
                         return p;
+                }
 
+        mutex_unlock(&pinctrl_list_mutex);
         return NULL;
 }
 
-static void pinctrl_put_locked(struct pinctrl *p, bool inlist);
+static void pinctrl_free(struct pinctrl *p, bool inlist);
 
 static struct pinctrl *create_pinctrl(struct device *dev)
 {
@@ -725,6 +769,7 @@ static struct pinctrl *create_pinctrl(struct device *dev)
 
         devname = dev_name(dev);
 
+        mutex_lock(&pinctrl_maps_mutex);
         /* Iterate over the pin control maps to locate the right ones */
         for_each_maps(maps_node, i, map) {
                 /* Map must be for this device */
@@ -746,13 +791,16 @@ static struct pinctrl *create_pinctrl(struct device *dev)
                  * an -EPROBE_DEFER later, as that is the worst case.
                  */
                 if (ret == -EPROBE_DEFER) {
-                        pinctrl_put_locked(p, false);
+                        pinctrl_free(p, false);
+                        mutex_unlock(&pinctrl_maps_mutex);
                         return ERR_PTR(ret);
                 }
         }
+        mutex_unlock(&pinctrl_maps_mutex);
+
         if (ret < 0) {
                 /* If some other error than deferral occured, return here */
-                pinctrl_put_locked(p, false);
+                pinctrl_free(p, false);
                 return ERR_PTR(ret);
         }
 
@@ -764,7 +812,11 @@ static struct pinctrl *create_pinctrl(struct device *dev)
         return p;
 }
 
-static struct pinctrl *pinctrl_get_locked(struct device *dev)
+/**
+ * pinctrl_get() - retrieves the pinctrl handle for a device
+ * @dev: the device to obtain the handle for
+ */
+struct pinctrl *pinctrl_get(struct device *dev)
 {
         struct pinctrl *p;
 
@@ -785,21 +837,6 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev)
 
         return create_pinctrl(dev);
 }
-
-/**
- * pinctrl_get() - retrieves the pinctrl handle for a device
- * @dev: the device to obtain the handle for
- */
-struct pinctrl *pinctrl_get(struct device *dev)
-{
-        struct pinctrl *p;
-
-        mutex_lock(&pinctrl_mutex);
-        p = pinctrl_get_locked(dev);
-        mutex_unlock(&pinctrl_mutex);
-
-        return p;
-}
 EXPORT_SYMBOL_GPL(pinctrl_get);
 
 static void pinctrl_free_setting(bool disable_setting,
@@ -820,11 +857,12 @@ static void pinctrl_free_setting(bool disable_setting,
         }
 }
 
-static void pinctrl_put_locked(struct pinctrl *p, bool inlist)
+static void pinctrl_free(struct pinctrl *p, bool inlist)
 {
         struct pinctrl_state *state, *n1;
         struct pinctrl_setting *setting, *n2;
 
+        mutex_lock(&pinctrl_list_mutex);
         list_for_each_entry_safe(state, n1, &p->states, node) {
                 list_for_each_entry_safe(setting, n2, &state->settings, node) {
                         pinctrl_free_setting(state == p->state, setting);
@@ -840,6 +878,7 @@ static void pinctrl_put_locked(struct pinctrl *p, bool inlist)
         if (inlist)
                 list_del(&p->node);
         kfree(p);
+        mutex_unlock(&pinctrl_list_mutex);
 }
 
 /**
@@ -850,7 +889,7 @@ static void pinctrl_release(struct kref *kref)
 {
         struct pinctrl *p = container_of(kref, struct pinctrl, users);
 
-        pinctrl_put_locked(p, true);
+        pinctrl_free(p, true);
 }
 
 /**
@@ -859,14 +898,17 @@ static void pinctrl_release(struct kref *kref)
  */
 void pinctrl_put(struct pinctrl *p)
 {
-        mutex_lock(&pinctrl_mutex);
         kref_put(&p->users, pinctrl_release);
-        mutex_unlock(&pinctrl_mutex);
 }
 EXPORT_SYMBOL_GPL(pinctrl_put);
 
-static struct pinctrl_state *pinctrl_lookup_state_locked(struct pinctrl *p,
-                                                         const char *name)
+/**
+ * pinctrl_lookup_state() - retrieves a state handle from a pinctrl handle
+ * @p: the pinctrl handle to retrieve the state from
+ * @name: the state name to retrieve
+ */
+struct pinctrl_state *pinctrl_lookup_state(struct pinctrl *p,
+                                                 const char *name)
 {
         struct pinctrl_state *state;
 
@@ -883,26 +925,14 @@ static struct pinctrl_state *pinctrl_lookup_state_locked(struct pinctrl *p,
 
         return state;
 }
+EXPORT_SYMBOL_GPL(pinctrl_lookup_state);
 
 /**
- * pinctrl_lookup_state() - retrieves a state handle from a pinctrl handle
- * @p: the pinctrl handle to retrieve the state from
- * @name: the state name to retrieve
+ * pinctrl_select_state() - select/activate/program a pinctrl state to HW
+ * @p: the pinctrl handle for the device that requests configuration
+ * @state: the state handle to select/activate/program
  */
-struct pinctrl_state *pinctrl_lookup_state(struct pinctrl *p, const char *name)
-{
-        struct pinctrl_state *s;
-
-        mutex_lock(&pinctrl_mutex);
-        s = pinctrl_lookup_state_locked(p, name);
-        mutex_unlock(&pinctrl_mutex);
-
-        return s;
-}
-EXPORT_SYMBOL_GPL(pinctrl_lookup_state);
-
-static int pinctrl_select_state_locked(struct pinctrl *p,
-                                       struct pinctrl_state *state)
+int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 {
         struct pinctrl_setting *setting, *setting2;
         struct pinctrl_state *old_state = p->state;
@@ -956,8 +986,9 @@ static int pinctrl_select_state_locked(struct pinctrl *p,
                         break;
                 }
 
-                if (ret < 0)
+                if (ret < 0) {
                         goto unapply_new_state;
+                }
         }
 
         p->state = state;
@@ -983,23 +1014,7 @@ unapply_new_state:
 
         /* There's no infinite recursive loop here because p->state is NULL */
         if (old_state)
-                pinctrl_select_state_locked(p, old_state);
-
-        return ret;
-}
-
-/**
- * pinctrl_select() - select/activate/program a pinctrl state to HW
- * @p: the pinctrl handle for the device that requests configuratio
- * @state: the state handle to select/activate/program
- */
-int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
-{
-        int ret;
-
-        mutex_lock(&pinctrl_mutex);
-        ret = pinctrl_select_state_locked(p, state);
-        mutex_unlock(&pinctrl_mutex);
+                pinctrl_select_state(p, old_state);
 
         return ret;
 }
@@ -1129,10 +1144,10 @@ int pinctrl_register_map(struct pinctrl_map const *maps, unsigned num_maps,
         }
 
         if (!locked)
-                mutex_lock(&pinctrl_mutex);
+                mutex_lock(&pinctrl_maps_mutex);
         list_add_tail(&maps_node->node, &pinctrl_maps);
         if (!locked)
-                mutex_unlock(&pinctrl_mutex);
+                mutex_unlock(&pinctrl_maps_mutex);
 
         return 0;
 }
@@ -1154,12 +1169,15 @@ void pinctrl_unregister_map(struct pinctrl_map const *map)
 {
         struct pinctrl_maps *maps_node;
 
+        mutex_lock(&pinctrl_maps_mutex);
         list_for_each_entry(maps_node, &pinctrl_maps, node) {
                 if (maps_node->maps == map) {
                         list_del(&maps_node->node);
+                        mutex_unlock(&pinctrl_maps_mutex);
                         return;
                 }
         }
+        mutex_unlock(&pinctrl_maps_mutex);
 }
 
 /**
@@ -1196,7 +1214,7 @@ static int pinctrl_pins_show(struct seq_file *s, void *what)
 
         seq_printf(s, "registered pins: %d\n", pctldev->desc->npins);
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
 
         /* The pin number can be retrived from the pin controller descriptor */
         for (i = 0; i < pctldev->desc->npins; i++) {
@@ -1218,7 +1236,7 @@ static int pinctrl_pins_show(struct seq_file *s, void *what)
                 seq_puts(s, "\n");
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }
@@ -1229,8 +1247,9 @@ static int pinctrl_groups_show(struct seq_file *s, void *what)
         const struct pinctrl_ops *ops = pctldev->desc->pctlops;
         unsigned ngroups, selector = 0;
 
+        mutex_lock(&pctldev->mutex);
+
         ngroups = ops->get_groups_count(pctldev);
-        mutex_lock(&pinctrl_mutex);
 
         seq_puts(s, "registered pin groups:\n");
         while (selector < ngroups) {
@@ -1251,7 +1270,7 @@ static int pinctrl_groups_show(struct seq_file *s, void *what)
                         for (i = 0; i < num_pins; i++) {
                                 pname = pin_get_name(pctldev, pins[i]);
                                 if (WARN_ON(!pname)) {
-                                        mutex_unlock(&pinctrl_mutex);
+                                        mutex_unlock(&pctldev->mutex);
                                         return -EINVAL;
                                 }
                                 seq_printf(s, "pin %d (%s)\n", pins[i], pname);
@@ -1261,7 +1280,7 @@ static int pinctrl_groups_show(struct seq_file *s, void *what)
                 selector++;
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }
@@ -1273,7 +1292,7 @@ static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
 
         seq_puts(s, "GPIO ranges handled:\n");
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
 
         /* Loop over the ranges */
         list_for_each_entry(range, &pctldev->gpio_ranges, node) {
@@ -1284,7 +1303,7 @@ static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
                            (range->pin_base + range->npins - 1));
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }
@@ -1295,7 +1314,7 @@ static int pinctrl_devices_show(struct seq_file *s, void *what)
 
         seq_puts(s, "name [pinmux] [pinconf]\n");
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pinctrldev_list_mutex);
 
         list_for_each_entry(pctldev, &pinctrldev_list, node) {
                 seq_printf(s, "%s ", pctldev->desc->name);
@@ -1310,7 +1329,7 @@ static int pinctrl_devices_show(struct seq_file *s, void *what)
                 seq_puts(s, "\n");
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pinctrldev_list_mutex);
 
         return 0;
 }
@@ -1339,8 +1358,7 @@ static int pinctrl_maps_show(struct seq_file *s, void *what)
 
         seq_puts(s, "Pinctrl maps:\n");
 
-        mutex_lock(&pinctrl_mutex);
-
+        mutex_lock(&pinctrl_maps_mutex);
         for_each_maps(maps_node, i, map) {
                 seq_printf(s, "device %s\nstate %s\ntype %s (%d)\n",
                            map->dev_name, map->name, map_type(map->type),
@@ -1364,8 +1382,7 @@ static int pinctrl_maps_show(struct seq_file *s, void *what)
 
                 seq_printf(s, "\n");
         }
-
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pinctrl_maps_mutex);
 
         return 0;
 }
@@ -1378,7 +1395,7 @@ static int pinctrl_show(struct seq_file *s, void *what)
 
         seq_puts(s, "Requested pin control handlers their pinmux maps:\n");
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pinctrl_list_mutex);
 
         list_for_each_entry(p, &pinctrl_list, node) {
                 seq_printf(s, "device: %s current state: %s\n",
@@ -1410,7 +1427,7 @@ static int pinctrl_show(struct seq_file *s, void *what)
                 }
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pinctrl_list_mutex);
 
         return 0;
 }
@@ -1596,6 +1613,7 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
         INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL);
         INIT_LIST_HEAD(&pctldev->gpio_ranges);
         pctldev->dev = dev;
+        mutex_init(&pctldev->mutex);
 
         /* check core ops for sanity */
         if (pinctrl_check_ops(pctldev)) {
@@ -1625,38 +1643,37 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
                 goto out_err;
         }
 
-        mutex_lock(&pinctrl_mutex);
-
+        mutex_lock(&pinctrldev_list_mutex);
         list_add_tail(&pctldev->node, &pinctrldev_list);
+        mutex_unlock(&pinctrldev_list_mutex);
+
+        pctldev->p = pinctrl_get(pctldev->dev);
 
-        pctldev->p = pinctrl_get_locked(pctldev->dev);
         if (!IS_ERR(pctldev->p)) {
                 pctldev->hog_default =
-                        pinctrl_lookup_state_locked(pctldev->p,
-                                                    PINCTRL_STATE_DEFAULT);
+                        pinctrl_lookup_state(pctldev->p, PINCTRL_STATE_DEFAULT);
                 if (IS_ERR(pctldev->hog_default)) {
                         dev_dbg(dev, "failed to lookup the default state\n");
                 } else {
-                        if (pinctrl_select_state_locked(pctldev->p,
+                        if (pinctrl_select_state(pctldev->p,
                                                 pctldev->hog_default))
                                 dev_err(dev,
                                         "failed to select default state\n");
                 }
 
                 pctldev->hog_sleep =
-                        pinctrl_lookup_state_locked(pctldev->p,
+                        pinctrl_lookup_state(pctldev->p,
                                                     PINCTRL_STATE_SLEEP);
                 if (IS_ERR(pctldev->hog_sleep))
                         dev_dbg(dev, "failed to lookup the sleep state\n");
         }
 
-        mutex_unlock(&pinctrl_mutex);
-
         pinctrl_init_device_debugfs(pctldev);
 
         return pctldev;
 
 out_err:
+        mutex_destroy(&pctldev->mutex);
         kfree(pctldev);
         return NULL;
 }
@@ -1674,12 +1691,13 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev)
         if (pctldev == NULL)
                 return;
 
-        pinctrl_remove_device_debugfs(pctldev);
+        mutex_lock(&pinctrldev_list_mutex);
+        mutex_lock(&pctldev->mutex);
 
-        mutex_lock(&pinctrl_mutex);
+        pinctrl_remove_device_debugfs(pctldev);
 
         if (!IS_ERR(pctldev->p))
-                pinctrl_put_locked(pctldev->p, true);
+                pinctrl_put(pctldev->p);
 
         /* TODO: check that no pinmuxes are still active? */
         list_del(&pctldev->node);
@@ -1690,9 +1708,10 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev)
         list_for_each_entry_safe(range, n, &pctldev->gpio_ranges, node)
                 list_del(&range->node);
 
+        mutex_unlock(&pctldev->mutex);
+        mutex_destroy(&pctldev->mutex);
         kfree(pctldev);
-
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pinctrldev_list_mutex);
 }
 EXPORT_SYMBOL_GPL(pinctrl_unregister);
 
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index 6d3d40036d1b..75476b3d87da 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -33,6 +33,7 @@ struct pinctrl_gpio_range;
  * @p: result of pinctrl_get() for this device
  * @hog_default: default state for pins hogged by this device
  * @hog_sleep: sleep state for pins hogged by this device
+ * @mutex: mutex taken on each pin controller specific action
  * @device_root: debugfs root for this device
  */
 struct pinctrl_dev {
@@ -46,6 +47,7 @@ struct pinctrl_dev {
         struct pinctrl *p;
         struct pinctrl_state *hog_default;
         struct pinctrl_state *hog_sleep;
+        struct mutex mutex;
 #ifdef CONFIG_DEBUG_FS
         struct dentry *device_root;
 #endif
@@ -168,6 +170,7 @@ struct pinctrl_maps {
 };
 
 struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *dev_name);
+struct pinctrl_dev *get_pinctrl_dev_from_of_node(struct device_node *np);
 int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name);
 const char *pin_get_name(struct pinctrl_dev *pctldev, const unsigned pin);
 int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
@@ -186,8 +189,7 @@ void pinctrl_unregister_map(struct pinctrl_map const *map);
 extern int pinctrl_force_sleep(struct pinctrl_dev *pctldev);
 extern int pinctrl_force_default(struct pinctrl_dev *pctldev);
 
-extern struct mutex pinctrl_mutex;
-extern struct list_head pinctrldev_list;
+extern struct mutex pinctrl_maps_mutex;
 extern struct list_head pinctrl_maps;
 
 #define for_each_maps(_maps_node_, _i_, _map_) \
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index c7b7cb477129..340fb4e6c600 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -95,22 +95,11 @@ static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
         return pinctrl_register_map(map, num_maps, false, true);
 }
 
-static struct pinctrl_dev *find_pinctrl_by_of_node(struct device_node *np)
-{
-        struct pinctrl_dev *pctldev;
-
-        list_for_each_entry(pctldev, &pinctrldev_list, node)
-                if (pctldev->dev->of_node == np)
-                        return pctldev;
-
-        return NULL;
-}
-
 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 {
         struct pinctrl_dev *pctldev;
 
-        pctldev = find_pinctrl_by_of_node(np);
+        pctldev = get_pinctrl_dev_from_of_node(np);
         if (!pctldev)
                 return NULL;
 
@@ -138,7 +127,7 @@ static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
                         /* OK let's just assume this will appear later then */
                         return -EPROBE_DEFER;
                 }
-                pctldev = find_pinctrl_by_of_node(np_pctldev);
+                pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
                 if (pctldev)
                         break;
                 /* Do not defer probing of hogs (circular loop) */
diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c
index 32f96808202a..c67c37e23dd7 100644
--- a/drivers/pinctrl/pinconf.c
+++ b/drivers/pinctrl/pinconf.c
@@ -89,14 +89,14 @@ int pin_config_get(const char *dev_name, const char *name,
         struct pinctrl_dev *pctldev;
         int pin;
 
-        mutex_lock(&pinctrl_mutex);
-
         pctldev = get_pinctrl_dev_from_devname(dev_name);
         if (!pctldev) {
                 pin = -EINVAL;
-                goto unlock;
+                return pin;
         }
 
+        mutex_lock(&pctldev->mutex);
+
         pin = pin_get_from_name(pctldev, name);
         if (pin < 0)
                 goto unlock;
@@ -104,7 +104,7 @@ int pin_config_get(const char *dev_name, const char *name,
         pin = pin_config_get_for_pin(pctldev, pin, config);
 
 unlock:
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
         return pin;
 }
 EXPORT_SYMBOL(pin_config_get);
@@ -145,14 +145,14 @@ int pin_config_set(const char *dev_name, const char *name,
         struct pinctrl_dev *pctldev;
         int pin, ret;
 
-        mutex_lock(&pinctrl_mutex);
-
         pctldev = get_pinctrl_dev_from_devname(dev_name);
         if (!pctldev) {
                 ret = -EINVAL;
-                goto unlock;
+                return ret;
         }
 
+        mutex_lock(&pctldev->mutex);
+
         pin = pin_get_from_name(pctldev, name);
         if (pin < 0) {
                 ret = pin;
@@ -162,7 +162,7 @@ int pin_config_set(const char *dev_name, const char *name,
         ret = pin_config_set_for_pin(pctldev, pin, config);
 
 unlock:
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
         return ret;
 }
 EXPORT_SYMBOL(pin_config_set);
@@ -174,13 +174,14 @@ int pin_config_group_get(const char *dev_name, const char *pin_group,
         const struct pinconf_ops *ops;
         int selector, ret;
 
-        mutex_lock(&pinctrl_mutex);
-
         pctldev = get_pinctrl_dev_from_devname(dev_name);
         if (!pctldev) {
                 ret = -EINVAL;
-                goto unlock;
+                return ret;
         }
+
+        mutex_lock(&pctldev->mutex);
+
         ops = pctldev->desc->confops;
 
         if (!ops || !ops->pin_config_group_get) {
@@ -200,7 +201,7 @@ int pin_config_group_get(const char *dev_name, const char *pin_group,
         ret = ops->pin_config_group_get(pctldev, selector, config);
 
 unlock:
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
         return ret;
 }
 EXPORT_SYMBOL(pin_config_group_get);
@@ -217,13 +218,14 @@ int pin_config_group_set(const char *dev_name, const char *pin_group,
         int ret;
         int i;
 
-        mutex_lock(&pinctrl_mutex);
-
         pctldev = get_pinctrl_dev_from_devname(dev_name);
         if (!pctldev) {
                 ret = -EINVAL;
-                goto unlock;
+                return ret;
         }
+
+        mutex_lock(&pctldev->mutex);
+
         ops = pctldev->desc->confops;
         pctlops = pctldev->desc->pctlops;
 
@@ -279,7 +281,7 @@ int pin_config_group_set(const char *dev_name, const char *pin_group,
         ret = 0;
 
 unlock:
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return ret;
 }
@@ -487,7 +489,7 @@ static int pinconf_pins_show(struct seq_file *s, void *what)
         seq_puts(s, "Pin config settings per pin\n");
         seq_puts(s, "Format: pin (name): configs\n");
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
 
         /* The pin number can be retrived from the pin controller descriptor */
         for (i = 0; i < pctldev->desc->npins; i++) {
@@ -507,7 +509,7 @@ static int pinconf_pins_show(struct seq_file *s, void *what)
                 seq_printf(s, "\n");
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }
@@ -608,7 +610,7 @@ static int pinconf_dbg_config_print(struct seq_file *s, void *d)
         bool found = false;
         unsigned long config;
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
 
         /* Parse the pinctrl map and look for the elected pin/state */
         for_each_maps(maps_node, i, map) {
@@ -657,7 +659,7 @@ static int pinconf_dbg_config_print(struct seq_file *s, void *d)
                 confops->pin_config_config_dbg_show(pctldev, s, config);
 
 exit:
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }
@@ -747,7 +749,7 @@ static int pinconf_dbg_config_write(struct file *file,
                 return -EINVAL;
         strncpy(config, token, MAX_NAME_LEN);
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pinctrl_maps_mutex);
 
         /* Parse the pinctrl map and look for the selected dev/state/pin */
         for_each_maps(maps_node, i, map) {
@@ -785,7 +787,7 @@ static int pinconf_dbg_config_write(struct file *file,
         }
 
 exit:
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pinctrl_maps_mutex);
 
         return count;
 }
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index bd83c8b01cd1..88cc5095d0c9 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -506,7 +506,7 @@ static int pinmux_functions_show(struct seq_file *s, void *what)
         if (!pmxops)
                 return 0;
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
         nfuncs = pmxops->get_functions_count(pctldev);
         while (func_selector < nfuncs) {
                 const char *func = pmxops->get_function_name(pctldev,
@@ -530,7 +530,7 @@ static int pinmux_functions_show(struct seq_file *s, void *what)
                 func_selector++;
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }
@@ -548,7 +548,7 @@ static int pinmux_pins_show(struct seq_file *s, void *what)
         seq_puts(s, "Pinmux settings per pin\n");
         seq_puts(s, "Format: pin (name): mux_owner gpio_owner hog?\n");
 
-        mutex_lock(&pinctrl_mutex);
+        mutex_lock(&pctldev->mutex);
 
         /* The pin number can be retrived from the pin controller descriptor */
         for (i = 0; i < pctldev->desc->npins; i++) {
@@ -583,7 +583,7 @@ static int pinmux_pins_show(struct seq_file *s, void *what)
                         seq_printf(s, "\n");
         }
 
-        mutex_unlock(&pinctrl_mutex);
+        mutex_unlock(&pctldev->mutex);
 
         return 0;
 }