Merge tag 'gpio-updates-for-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "The majority of added lines are two new modules: the GPIO virtual
  consumer module that improves our ability to add automated tests for
  the kernel API and the "sloppy" logic analyzer module that uses the
  GPIO API to implement a coarse-grained debugging tool for useful for
  remote development.

  Other than that we have the usual assortment of various driver
  extensions, improvements to the core GPIO code, DT-bindings and other
  documentation updates as well as an extension to the interrupt
  simulator:

  GPIOLIB core:
   - rework kfifo handling rework in the character device code
   - improve the labeling of GPIOs requested as interrupts and show more
     info on interrupt-only GPIOs in debugfs
   - remove unused APIs
   - unexport interfaces that are only used from the core GPIO code
   - drop the return value from gpiochip_set_desc_names() as it cannot
     fail
   - move a string array definition out of a header and into a specific
     compilation unit
   - convert the last user of gpiochip_get_desc() other than GPIO core
     to using a safer alternative
   - use array_index_nospec() where applicable

  New drivers:
   - add a "virtual GPIO consumer" module that allows requesting GPIOs
     from actual hardware and driving tests of the in-kernel GPIO API
     from user-space over debugfs
   - add a GPIO-based "sloppy" logic analyzer module useful for "first
     glance" debugging on remote boards

  Driver improvements:
   - add support for a new model to gpio-pca953x
   - lock GPIOs as interrupts in gpio-sim when the lines are requested
     as irqs via the simulator domain + some other minor improvements
   - improve error reporting in gpio-syscon
   - convert gpio-ath79 to using dynamic GPIO base and range
   - use pcibios_err_to_errno() for converting PCIBIOS error codes to
     errno vaues in gpio-amd8111 and gpio-rdc321x
   - allow building gpio-brcmstb for the BCM2835 architecture

  DT bindings:
   - convert DT bindings for lsi,zevio, mpc8xxx, and atmel to DT schema
   - document new properties for aspeed,gpio, fsl,qoriq-gpio and
     gpio-vf610
   - document new compatibles for pca953x and fsl,qoriq-gpio

  Documentation:
   - document stricter behavior of the GPIO character device uAPI with
     regards to reconfiguring requested line without direction set
   - clarify the effect of the active-low flag on line values and edges
   - remove documentation for the legacy GPIO API in order to stop
     tempting people to use it
   - document the preference for using pread() for reading edge events
     in the sysfs API

  Other:
   - add an extended initializer to the interrupt simulator allowing to
     specify a number of callbacks callers can use to be notified about
     irqs being requested and released"

* tag 'gpio-updates-for-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (41 commits)
  gpio: mc33880: Convert comma to semicolon
  gpio: virtuser: actually use the "trimmed" local variable
  dt-bindings: gpio: convert Atmel GPIO to json-schema
  gpio: virtuser: new virtual testing driver for the GPIO API
  dt-bindings: gpio: vf610: Allow gpio-line-names to be set
  gpio: sim: lock GPIOs as interrupts when they are requested
  genirq/irq_sim: add an extended irq_sim initializer
  dt-bindings: gpio: fsl,qoriq-gpio: Add compatible string fsl,ls1046a-gpio
  gpiolib: unexport gpiochip_get_desc()
  gpio: add sloppy logic analyzer using polling
  Documentation: gpio: Reconfiguration with unset direction (uAPI v2)
  Documentation: gpio: Reconfiguration with unset direction (uAPI v1)
  dt-bindings: gpio: fsl,qoriq-gpio: add common property gpio-line-names
  gpio: ath79: convert to dynamic GPIO base allocation
  pinctrl: da9062: replace gpiochip_get_desc() with gpio_device_get_desc()
  gpiolib: put gpio_suffixes in a single compilation unit
  Documentation: gpio: Clarify effect of active low flag on line edges
  Documentation: gpio: Clarify effect of active low flag on line values
  gpiolib: Remove data-less gpiochip_add() function
  gpio: sim: use devm_mutex_init()
  ...

1 files changed, 41 insertions, 39 deletions

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 5639abce6ec5..ef08b23a56e2 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -1132,6 +1132,14 @@ static void edge_detector_stop(struct line *line)
 	/* do not change line->level - see comment in debounced_value() */
 }
 
+static int edge_detector_fifo_init(struct linereq *req)
+{
+	if (kfifo_initialized(&req->events))
+		return 0;
+
+	return kfifo_alloc(&req->events, req->event_buffer_size, GFP_KERNEL);
+}
+
 static int edge_detector_setup(struct line *line,
 			       struct gpio_v2_line_config *lc,
 			       unsigned int line_idx, u64 edflags)
@@ -1143,9 +1151,8 @@ static int edge_detector_setup(struct line *line,
 	char *label;
 
 	eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS;
-	if (eflags && !kfifo_initialized(&line->req->events)) {
-		ret = kfifo_alloc(&line->req->events,
-				  line->req->event_buffer_size, GFP_KERNEL);
+	if (eflags) {
+		ret = edge_detector_fifo_init(line->req);
 		if (ret)
 			return ret;
 	}
@@ -1197,8 +1204,6 @@ static int edge_detector_update(struct line *line,
 				struct gpio_v2_line_config *lc,
 				unsigned int line_idx, u64 edflags)
 {
-	u64 eflags;
-	int ret;
 	u64 active_edflags = READ_ONCE(line->edflags);
 	unsigned int debounce_period_us =
 			gpio_v2_line_config_debounce_period(lc, line_idx);
@@ -1214,14 +1219,9 @@ static int edge_detector_update(struct line *line,
 		 * ensure event fifo is initialised if edge detection
 		 * is now enabled.
 		 */
-		eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS;
-		if (eflags && !kfifo_initialized(&line->req->events)) {
-			ret = kfifo_alloc(&line->req->events,
-					  line->req->event_buffer_size,
-					  GFP_KERNEL);
-			if (ret)
-				return ret;
-		}
+		if (edflags & GPIO_V2_LINE_EDGE_FLAGS)
+			return edge_detector_fifo_init(line->req);
+
 		return 0;
 	}
 
@@ -1648,16 +1648,15 @@ static ssize_t linereq_read(struct file *file, char __user *buf,
 					return ret;
 			}
 
-			ret = kfifo_out(&lr->events, &le, 1);
-		}
-		if (ret != 1) {
-			/*
-			 * This should never happen - we were holding the
-			 * lock from the moment we learned the fifo is no
-			 * longer empty until now.
-			 */
-			ret = -EIO;
-			break;
+			if (kfifo_out(&lr->events, &le, 1) != 1) {
+				/*
+				 * This should never happen - we hold the
+				 * lock from the moment we learned the fifo
+				 * is no longer empty until now.
+				 */
+				WARN(1, "failed to read from non-empty kfifo");
+				return -EIO;
+			}
 		}
 
 		if (copy_to_user(buf + bytes_read, &le, sizeof(le)))
@@ -1780,6 +1779,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
 
 	mutex_init(&lr->config_mutex);
 	init_waitqueue_head(&lr->wait);
+	INIT_KFIFO(lr->events);
 	lr->event_buffer_size = ulr.event_buffer_size;
 	if (lr->event_buffer_size == 0)
 		lr->event_buffer_size = ulr.num_lines * 16;
@@ -2000,16 +2000,15 @@ static ssize_t lineevent_read(struct file *file, char __user *buf,
 					return ret;
 			}
 
-			ret = kfifo_out(&le->events, &ge, 1);
-		}
-		if (ret != 1) {
-			/*
-			 * This should never happen - we were holding the lock
-			 * from the moment we learned the fifo is no longer
-			 * empty until now.
-			 */
-			ret = -EIO;
-			break;
+			if (kfifo_out(&le->events, &ge, 1) != 1) {
+				/*
+				 * This should never happen - we hold the
+				 * lock from the moment we learned the fifo
+				 * is no longer empty until now.
+				 */
+				WARN(1, "failed to read from non-empty kfifo");
+				return -EIO;
+			}
 		}
 
 		if (copy_to_user(buf + bytes_read, &ge, ge_size))
@@ -2712,12 +2711,15 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
 			if (count < event_size)
 				return -EINVAL;
 #endif
-			ret = kfifo_out(&cdev->events, &event, 1);
-		}
-		if (ret != 1) {
-			ret = -EIO;
-			break;
-			/* We should never get here. See lineevent_read(). */
+			if (kfifo_out(&cdev->events, &event, 1) != 1) {
+				/*
+				 * This should never happen - we hold the
+				 * lock from the moment we learned the fifo
+				 * is no longer empty until now.
+				 */
+				WARN(1, "failed to read from non-empty kfifo");
+				return -EIO;
+			}
 		}
 
 #ifdef CONFIG_GPIO_CDEV_V1