[PATCH v2] pinctrl: move subsystem mutex to pinctrl_dev struct

From: Linus Walleij
Date: Wed Apr 24 2013 - 05:02:22 EST

From: Patrice Chotard <patrice.chotard@xxxxxx>

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 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@xxxxxxxxxxxxxx>
Signed-off-by: Patrice Chotard <patrice.chotard@xxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/pinctrl/core.c | 266 +++++++++++++++++++++++--------------------
drivers/pinctrl/core.h | 6 +-
drivers/pinctrl/devicetree.c | 15 +--
drivers/pinctrl/pinconf.c | 46 ++++----
drivers/pinctrl/pinmux.c | 8 +-
5 files changed, 176 insertions(+), 165 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 8b832ce..37cd774 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;
@@ -983,28 +1014,11 @@ 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);
+ pinctrl_select_state(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);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(pinctrl_select_state);
-
static void devm_pinctrl_release(struct device *dev, void *res)
{
pinctrl_put(*(struct pinctrl **)res);
@@ -1129,10 +1143,10 @@ 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 +1168,15 @@ 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 +1213,7 @@ 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 +1235,7 @@ 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 +1246,9 @@ 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 +1269,7 @@ 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 +1279,7 @@ static int pinctrl_groups_show(struct seq_file *s, void *what)
selector++;
}

- mutex_unlock(&pinctrl_mutex);
+ mutex_unlock(&pctldev->mutex);

return 0;
}
@@ -1273,7 +1291,7 @@ 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 +1302,7 @@ 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 +1313,7 @@ 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 +1328,7 @@ 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 +1357,7 @@ 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 +1381,7 @@ 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 +1394,7 @@ 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 +1426,7 @@ static int pinctrl_show(struct seq_file *s, void *what)
}
}

- mutex_unlock(&pinctrl_mutex);
+ mutex_unlock(&pinctrl_list_mutex);

return 0;
}
@@ -1596,6 +1612,7 @@ 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 +1642,37 @@ 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 +1690,13 @@ 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 +1707,10 @@ 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 6d3d400..75476b3 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 c7b7cb4..340fb4e 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 6f14b62..3578667 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 bd83c8b..88cc509 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;
}
--
1.7.11.3

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