Merge tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "We have a new GPIO multiplexer driver, bunch of driver updates and
  refactoring in the core GPIO library.

  GPIO core:
   - teach gpiolib to work with software nodes for HW description
   - remove ARCH_NR_GPIOS treewide as we no longer impose any limit on
     the number of GPIOS since the allocation became entirely dynamic
   - add support for HW quirks for Cirrus CS42L56 codec, Marvell NFC
     controller, Freescale PCIe and Ethernet controller, Himax LCDs and
     Mediatek mt2701
   - refactor OF quirk code
   - some general refactoring of the OF and ACPI code, adding new
     helpers, minor tweaks and fixes, making fwnode usage consistent
     etc.

  GPIO uAPI:
   - fix an issue where the user-space can trigger a NULL-pointer
     dereference in the kernel by opening a device file, forcing a
     driver unbind and then calling one of the syscalls on the
     associated file descriptor

  New drivers:
   - add gpio-latch: a new GPIO multiplexer based on latches connected
     to other GPIOs

  Driver updates:
   - convert i2c GPIO expanders to using .probe_new()
   - drop the gpio-sta2x11 driver
   - factor out common code for the ACCES IDIO-16 family of controllers
     and use this new library wherever applicable in drivers
   - add DT support to gpio-hisi
   - allow building gpio-davinci as a module and increase its maxItems
     property
   - add support for a new model to gpio-pca9570
   - other minor changes to various drivers"

* tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (66 commits)
  gpio: sim: set a limit on the number of GPIOs
  gpiolib: protect the GPIO device against being dropped while in use by user-space
  gpiolib: cdev: fix NULL-pointer dereferences
  gpiolib: Provide to_gpio_device() helper
  gpiolib: Unify access to the device properties
  gpio: Do not include <linux/kernel.h> when not really needed.
  gpio: pcf857x: Convert to i2c's .probe_new()
  gpio: pca953x: Convert to i2c's .probe_new()
  gpio: max732x: Convert to i2c's .probe_new()
  dt-bindings: gpio: gpio-davinci: Increase maxItems in gpio-line-names
  gpiolib: ensure that fwnode is properly set
  gpio: sl28cpld: Replace irqchip mask_invert with unmask_base
  gpiolib: of: Use correct fwnode for DT-probed chips
  gpiolib: of: Drop redundant check in of_mm_gpiochip_remove()
  gpiolib: of: Prepare of_mm_gpiochip_add_data() for fwnode
  gpiolib: add support for software nodes
  gpiolib: consolidate GPIO lookups
  gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
  gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
  gpiolib: acpi: change acpi_find_gpio() to accept firmware node
  ...

1 files changed, 180 insertions, 26 deletions

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 65b2c09a4576..e878e3f22b0e 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -57,6 +57,50 @@ static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8));
  * interface to gpiolib GPIOs via ioctl()s.
  */
 
+typedef __poll_t (*poll_fn)(struct file *, struct poll_table_struct *);
+typedef long (*ioctl_fn)(struct file *, unsigned int, unsigned long);
+typedef ssize_t (*read_fn)(struct file *, char __user *,
+			   size_t count, loff_t *);
+
+static __poll_t call_poll_locked(struct file *file,
+				 struct poll_table_struct *wait,
+				 struct gpio_device *gdev, poll_fn func)
+{
+	__poll_t ret;
+
+	down_read(&gdev->sem);
+	ret = func(file, wait);
+	up_read(&gdev->sem);
+
+	return ret;
+}
+
+static long call_ioctl_locked(struct file *file, unsigned int cmd,
+			      unsigned long arg, struct gpio_device *gdev,
+			      ioctl_fn func)
+{
+	long ret;
+
+	down_read(&gdev->sem);
+	ret = func(file, cmd, arg);
+	up_read(&gdev->sem);
+
+	return ret;
+}
+
+static ssize_t call_read_locked(struct file *file, char __user *buf,
+				size_t count, loff_t *f_ps,
+				struct gpio_device *gdev, read_fn func)
+{
+	ssize_t ret;
+
+	down_read(&gdev->sem);
+	ret = func(file, buf, count, f_ps);
+	up_read(&gdev->sem);
+
+	return ret;
+}
+
 /*
  * GPIO line handle management
  */
@@ -193,8 +237,8 @@ static long linehandle_set_config(struct linehandle_state *lh,
 	return 0;
 }
 
-static long linehandle_ioctl(struct file *file, unsigned int cmd,
-			     unsigned long arg)
+static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd,
+				      unsigned long arg)
 {
 	struct linehandle_state *lh = file->private_data;
 	void __user *ip = (void __user *)arg;
@@ -203,6 +247,9 @@ static long linehandle_ioctl(struct file *file, unsigned int cmd,
 	unsigned int i;
 	int ret;
 
+	if (!lh->gdev->chip)
+		return -ENODEV;
+
 	switch (cmd) {
 	case GPIOHANDLE_GET_LINE_VALUES_IOCTL:
 		/* NOTE: It's okay to read values of output lines */
@@ -249,6 +296,15 @@ static long linehandle_ioctl(struct file *file, unsigned int cmd,
 	}
 }
 
+static long linehandle_ioctl(struct file *file, unsigned int cmd,
+			     unsigned long arg)
+{
+	struct linehandle_state *lh = file->private_data;
+
+	return call_ioctl_locked(file, cmd, arg, lh->gdev,
+				 linehandle_ioctl_unlocked);
+}
+
 #ifdef CONFIG_COMPAT
 static long linehandle_ioctl_compat(struct file *file, unsigned int cmd,
 				    unsigned long arg)
@@ -412,7 +468,7 @@ out_free_lh:
  * @desc: the GPIO descriptor for this line.
  * @req: the corresponding line request
  * @irq: the interrupt triggered in response to events on this GPIO
- * @eflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or
+ * @edflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or
  * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied
  * @timestamp_ns: cache for the timestamp storing it between hardirq and
  * IRQ thread, used to bring the timestamp close to the actual event
@@ -1380,12 +1436,15 @@ static long linereq_set_config(struct linereq *lr, void __user *ip)
 	return ret;
 }
 
-static long linereq_ioctl(struct file *file, unsigned int cmd,
-			  unsigned long arg)
+static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd,
+				   unsigned long arg)
 {
 	struct linereq *lr = file->private_data;
 	void __user *ip = (void __user *)arg;
 
+	if (!lr->gdev->chip)
+		return -ENODEV;
+
 	switch (cmd) {
 	case GPIO_V2_LINE_GET_VALUES_IOCTL:
 		return linereq_get_values(lr, ip);
@@ -1398,6 +1457,15 @@ static long linereq_ioctl(struct file *file, unsigned int cmd,
 	}
 }
 
+static long linereq_ioctl(struct file *file, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct linereq *lr = file->private_data;
+
+	return call_ioctl_locked(file, cmd, arg, lr->gdev,
+				 linereq_ioctl_unlocked);
+}
+
 #ifdef CONFIG_COMPAT
 static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
 				 unsigned long arg)
@@ -1406,12 +1474,15 @@ static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
 }
 #endif
 
-static __poll_t linereq_poll(struct file *file,
-			    struct poll_table_struct *wait)
+static __poll_t linereq_poll_unlocked(struct file *file,
+				      struct poll_table_struct *wait)
 {
 	struct linereq *lr = file->private_data;
 	__poll_t events = 0;
 
+	if (!lr->gdev->chip)
+		return EPOLLHUP | EPOLLERR;
+
 	poll_wait(file, &lr->wait, wait);
 
 	if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events,
@@ -1421,16 +1492,25 @@ static __poll_t linereq_poll(struct file *file,
 	return events;
 }
 
-static ssize_t linereq_read(struct file *file,
-			    char __user *buf,
-			    size_t count,
-			    loff_t *f_ps)
+static __poll_t linereq_poll(struct file *file,
+			     struct poll_table_struct *wait)
+{
+	struct linereq *lr = file->private_data;
+
+	return call_poll_locked(file, wait, lr->gdev, linereq_poll_unlocked);
+}
+
+static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
+				     size_t count, loff_t *f_ps)
 {
 	struct linereq *lr = file->private_data;
 	struct gpio_v2_line_event le;
 	ssize_t bytes_read = 0;
 	int ret;
 
+	if (!lr->gdev->chip)
+		return -ENODEV;
+
 	if (count < sizeof(le))
 		return -EINVAL;
 
@@ -1475,6 +1555,15 @@ static ssize_t linereq_read(struct file *file,
 	return bytes_read;
 }
 
+static ssize_t linereq_read(struct file *file, char __user *buf,
+			    size_t count, loff_t *f_ps)
+{
+	struct linereq *lr = file->private_data;
+
+	return call_read_locked(file, buf, count, f_ps, lr->gdev,
+				linereq_read_unlocked);
+}
+
 static void linereq_free(struct linereq *lr)
 {
 	unsigned int i;
@@ -1712,12 +1801,15 @@ struct lineevent_state {
 	(GPIOEVENT_REQUEST_RISING_EDGE | \
 	GPIOEVENT_REQUEST_FALLING_EDGE)
 
-static __poll_t lineevent_poll(struct file *file,
-			       struct poll_table_struct *wait)
+static __poll_t lineevent_poll_unlocked(struct file *file,
+					struct poll_table_struct *wait)
 {
 	struct lineevent_state *le = file->private_data;
 	__poll_t events = 0;
 
+	if (!le->gdev->chip)
+		return EPOLLHUP | EPOLLERR;
+
 	poll_wait(file, &le->wait, wait);
 
 	if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock))
@@ -1726,15 +1818,21 @@ static __poll_t lineevent_poll(struct file *file,
 	return events;
 }
 
+static __poll_t lineevent_poll(struct file *file,
+			       struct poll_table_struct *wait)
+{
+	struct lineevent_state *le = file->private_data;
+
+	return call_poll_locked(file, wait, le->gdev, lineevent_poll_unlocked);
+}
+
 struct compat_gpioeevent_data {
 	compat_u64	timestamp;
 	u32		id;
 };
 
-static ssize_t lineevent_read(struct file *file,
-			      char __user *buf,
-			      size_t count,
-			      loff_t *f_ps)
+static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf,
+				       size_t count, loff_t *f_ps)
 {
 	struct lineevent_state *le = file->private_data;
 	struct gpioevent_data ge;
@@ -1742,6 +1840,9 @@ static ssize_t lineevent_read(struct file *file,
 	ssize_t ge_size;
 	int ret;
 
+	if (!le->gdev->chip)
+		return -ENODEV;
+
 	/*
 	 * When compatible system call is being used the struct gpioevent_data,
 	 * in case of at least ia32, has different size due to the alignment
@@ -1799,6 +1900,15 @@ static ssize_t lineevent_read(struct file *file,
 	return bytes_read;
 }
 
+static ssize_t lineevent_read(struct file *file, char __user *buf,
+			      size_t count, loff_t *f_ps)
+{
+	struct lineevent_state *le = file->private_data;
+
+	return call_read_locked(file, buf, count, f_ps, le->gdev,
+				lineevent_read_unlocked);
+}
+
 static void lineevent_free(struct lineevent_state *le)
 {
 	if (le->irq)
@@ -1816,13 +1926,16 @@ static int lineevent_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static long lineevent_ioctl(struct file *file, unsigned int cmd,
-			    unsigned long arg)
+static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd,
+				     unsigned long arg)
 {
 	struct lineevent_state *le = file->private_data;
 	void __user *ip = (void __user *)arg;
 	struct gpiohandle_data ghd;
 
+	if (!le->gdev->chip)
+		return -ENODEV;
+
 	/*
 	 * We can get the value for an event line but not set it,
 	 * because it is input by definition.
@@ -1845,6 +1958,15 @@ static long lineevent_ioctl(struct file *file, unsigned int cmd,
 	return -EINVAL;
 }
 
+static long lineevent_ioctl(struct file *file, unsigned int cmd,
+			    unsigned long arg)
+{
+	struct lineevent_state *le = file->private_data;
+
+	return call_ioctl_locked(file, cmd, arg, le->gdev,
+				 lineevent_ioctl_unlocked);
+}
+
 #ifdef CONFIG_COMPAT
 static long lineevent_ioctl_compat(struct file *file, unsigned int cmd,
 				   unsigned long arg)
@@ -2403,12 +2525,15 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
-static __poll_t lineinfo_watch_poll(struct file *file,
-				    struct poll_table_struct *pollt)
+static __poll_t lineinfo_watch_poll_unlocked(struct file *file,
+					     struct poll_table_struct *pollt)
 {
 	struct gpio_chardev_data *cdev = file->private_data;
 	__poll_t events = 0;
 
+	if (!cdev->gdev->chip)
+		return EPOLLHUP | EPOLLERR;
+
 	poll_wait(file, &cdev->wait, pollt);
 
 	if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events,
@@ -2418,8 +2543,17 @@ static __poll_t lineinfo_watch_poll(struct file *file,
 	return events;
 }
 
-static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
-				   size_t count, loff_t *off)
+static __poll_t lineinfo_watch_poll(struct file *file,
+				    struct poll_table_struct *pollt)
+{
+	struct gpio_chardev_data *cdev = file->private_data;
+
+	return call_poll_locked(file, pollt, cdev->gdev,
+				lineinfo_watch_poll_unlocked);
+}
+
+static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf,
+					    size_t count, loff_t *off)
 {
 	struct gpio_chardev_data *cdev = file->private_data;
 	struct gpio_v2_line_info_changed event;
@@ -2427,6 +2561,9 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
 	int ret;
 	size_t event_size;
 
+	if (!cdev->gdev->chip)
+		return -ENODEV;
+
 #ifndef CONFIG_GPIO_CDEV_V1
 	event_size = sizeof(struct gpio_v2_line_info_changed);
 	if (count < event_size)
@@ -2494,6 +2631,15 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
 	return bytes_read;
 }
 
+static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
+				   size_t count, loff_t *off)
+{
+	struct gpio_chardev_data *cdev = file->private_data;
+
+	return call_read_locked(file, buf, count, off, cdev->gdev,
+				lineinfo_watch_read_unlocked);
+}
+
 /**
  * gpio_chrdev_open() - open the chardev for ioctl operations
  * @inode: inode for this chardev
@@ -2507,13 +2653,17 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	struct gpio_chardev_data *cdev;
 	int ret = -ENOMEM;
 
+	down_read(&gdev->sem);
+
 	/* Fail on open if the backing gpiochip is gone */
-	if (!gdev->chip)
-		return -ENODEV;
+	if (!gdev->chip) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
 
 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
-		return -ENOMEM;
+		goto out_unlock;
 
 	cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
 	if (!cdev->watched_lines)
@@ -2536,6 +2686,8 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	if (ret)
 		goto out_unregister_notifier;
 
+	up_read(&gdev->sem);
+
 	return ret;
 
 out_unregister_notifier:
@@ -2545,6 +2697,8 @@ out_free_bitmap:
 	bitmap_free(cdev->watched_lines);
 out_free_cdev:
 	kfree(cdev);
+out_unlock:
+	up_read(&gdev->sem);
 	return ret;
 }