Merge tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This time very little driver changes but lots of core changes.

  We have some interesting cooperative work for ARM and Intel alike,
  making the GPIO subsystem more and more suitable for industrial
  systems and the like, in addition to the in-kernel users.

  We touch driver core (device properties) and lib/* by adding one
  simple string array free function, these are authored by Andy
  Shevchenko who is a well known and recognized core helpers maintainers
  so this should be fine.

  We also see some Android GKI-related modularization in the MXC
  drivers.

  Core changes:

   - The big core change is the updated (v2) userspace character device
     API.

     This corrects badly designed 64-bit alignment around the line
     events. We also add the debounce request feature. This echoes the
     often quotes passage from Frederick Brooks "The mythical man-month"
     to always throw one away, which we have seen before in things such
     as V4L2. So we put in a new one and deprecate and obsolete the old
     one.

   - All example tools in tools/gpio/* are migrated to the new API to
     set a good example. The libgpiod userspace library has been
     augmented to use this new API pretty much from day 1.

   - Some misc API hardening by using strn* function calls has been
     added as well.

   - Use the simpler IDA interface for GPIO chip instance enumeration.

   - Add device core function for counting string arrays in device
     properties.

   - Provide a generic library function kfree_strarray() that can be
     used throughout the kernel.

  Driver enhancements:

   - The DesignWare dwapb-gpio driver has been enhanced and now uses the
     IRQ handling in the gpiolib core.

   - The mockup and aggregator drivers have seen some substantial code
     clean-up and now use more of the core kernel inftrastructure.

   - Misc cleanups using dev_err_probe().

   - The MXC drivers (Freescale/NXP) can now be built modularized, which
     makes modularized GKI Android kernels happy"

* tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits)
  gpiolib: Update header block in gpiolib-cdev.h
  gpiolib: cdev: switch from kstrdup() to kstrndup()
  docs: gpio: add a new document to its index.rst
  gpio: pca953x: Add support for the NXP PCAL9554B/C
  tools: gpio: add debounce support to gpio-event-mon
  tools: gpio: add multi-line monitoring to gpio-event-mon
  tools: gpio: port gpio-event-mon to v2 uAPI
  tools: gpio: port gpio-hammer to v2 uAPI
  tools: gpio: rename nlines to num_lines
  tools: gpio: port gpio-watch to v2 uAPI
  tools: gpio: port lsgpio to v2 uAPI
  gpio: uapi: document uAPI v1 as deprecated
  gpiolib: cdev: support setting debounce
  gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
  gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
  gpiolib: cdev: support edge detection for uAPI v2
  gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL
  gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL
  gpiolib: add build option for CDEV v1 ABI
  gpiolib: make cdev a build option
  ...

1 files changed, 1261 insertions, 53 deletions

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index fed5a3b2172f..e9faeaf65d14 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -1,9 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/anon_inodes.h>
+#include <linux/atomic.h>
 #include <linux/bitmap.h>
+#include <linux/build_bug.h>
 #include <linux/cdev.h>
 #include <linux/compat.h>
+#include <linux/compiler.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/file.h>
@@ -14,16 +17,37 @@
 #include <linux/kernel.h>
 #include <linux/kfifo.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/poll.h>
 #include <linux/spinlock.h>
 #include <linux/timekeeping.h>
 #include <linux/uaccess.h>
+#include <linux/workqueue.h>
 #include <uapi/linux/gpio.h>
 
 #include "gpiolib.h"
 #include "gpiolib-cdev.h"
 
+/*
+ * Array sizes must ensure 64-bit alignment and not create holes in the
+ * struct packing.
+ */
+static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2));
+static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8));
+
+/*
+ * Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility
+ */
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8));
+static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8));
+
 /* Character device interface to GPIO.
  *
  * The GPIO character device, /dev/gpiochipN, provides userspace an
@@ -34,6 +58,7 @@
  * GPIO line handle management
  */
 
+#ifdef CONFIG_GPIO_CDEV_V1
 /**
  * struct linehandle_state - contains the state of a userspace handle
  * @gdev: the GPIO device the handle pertains to
@@ -159,7 +184,8 @@ static long linehandle_set_config(struct linehandle_state *lh,
 		}
 
 		blocking_notifier_call_chain(&desc->gdev->notifier,
-					     GPIOLINE_CHANGED_CONFIG, desc);
+					     GPIO_V2_LINE_CHANGED_CONFIG,
+					     desc);
 	}
 	return 0;
 }
@@ -281,11 +307,11 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 	lh->gdev = gdev;
 	get_device(&gdev->dev);
 
-	/* Make sure this is terminated */
-	handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
-	if (strlen(handlereq.consumer_label)) {
-		lh->label = kstrdup(handlereq.consumer_label,
-				    GFP_KERNEL);
+	if (handlereq.consumer_label[0] != '\0') {
+		/* label is only initialized if consumer_label is set */
+		lh->label = kstrndup(handlereq.consumer_label,
+				     sizeof(handlereq.consumer_label) - 1,
+				     GFP_KERNEL);
 		if (!lh->label) {
 			ret = -ENOMEM;
 			goto out_free_lh;
@@ -331,7 +357,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 		}
 
 		blocking_notifier_call_chain(&desc->gdev->notifier,
-					     GPIOLINE_CHANGED_REQUESTED, desc);
+					     GPIO_V2_LINE_CHANGED_REQUESTED, desc);
 
 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
 			offset);
@@ -376,6 +402,1036 @@ out_free_lh:
 	linehandle_free(lh);
 	return ret;
 }
+#endif /* CONFIG_GPIO_CDEV_V1 */
+
+/**
+ * struct line - contains the state of a requested line
+ * @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
+ * 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
+ * @req_seqno: the seqno for the current edge event in the sequence of
+ * events for the corresponding line request. This is drawn from the @req.
+ * @line_seqno: the seqno for the current edge event in the sequence of
+ * events for this line.
+ * @work: the worker that implements software debouncing
+ * @sw_debounced: flag indicating if the software debouncer is active
+ * @level: the current debounced physical level of the line
+ */
+struct line {
+	struct gpio_desc *desc;
+	/*
+	 * -- edge detector specific fields --
+	 */
+	struct linereq *req;
+	unsigned int irq;
+	u64 eflags;
+	/*
+	 * timestamp_ns and req_seqno are accessed only by
+	 * edge_irq_handler() and edge_irq_thread(), which are themselves
+	 * mutually exclusive, so no additional protection is necessary.
+	 */
+	u64 timestamp_ns;
+	u32 req_seqno;
+	/*
+	 * line_seqno is accessed by either edge_irq_thread() or
+	 * debounce_work_func(), which are themselves mutually exclusive,
+	 * so no additional protection is necessary.
+	 */
+	u32 line_seqno;
+	/*
+	 * -- debouncer specific fields --
+	 */
+	struct delayed_work work;
+	/*
+	 * sw_debounce is accessed by linereq_set_config(), which is the
+	 * only setter, and linereq_get_values(), which can live with a
+	 * slightly stale value.
+	 */
+	unsigned int sw_debounced;
+	/*
+	 * level is accessed by debounce_work_func(), which is the only
+	 * setter, and linereq_get_values() which can live with a slightly
+	 * stale value.
+	 */
+	unsigned int level;
+};
+
+/**
+ * struct linereq - contains the state of a userspace line request
+ * @gdev: the GPIO device the line request pertains to
+ * @label: consumer label used to tag GPIO descriptors
+ * @num_lines: the number of lines in the lines array
+ * @wait: wait queue that handles blocking reads of events
+ * @event_buffer_size: the number of elements allocated in @events
+ * @events: KFIFO for the GPIO events
+ * @seqno: the sequence number for edge events generated on all lines in
+ * this line request.  Note that this is not used when @num_lines is 1, as
+ * the line_seqno is then the same and is cheaper to calculate.
+ * @config_mutex: mutex for serializing ioctl() calls to ensure consistency
+ * of configuration, particularly multi-step accesses to desc flags.
+ * @lines: the lines held by this line request, with @num_lines elements.
+ */
+struct linereq {
+	struct gpio_device *gdev;
+	const char *label;
+	u32 num_lines;
+	wait_queue_head_t wait;
+	u32 event_buffer_size;
+	DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event);
+	atomic_t seqno;
+	struct mutex config_mutex;
+	struct line lines[];
+};
+
+#define GPIO_V2_LINE_BIAS_FLAGS \
+	(GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \
+	 GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \
+	 GPIO_V2_LINE_FLAG_BIAS_DISABLED)
+
+#define GPIO_V2_LINE_DIRECTION_FLAGS \
+	(GPIO_V2_LINE_FLAG_INPUT | \
+	 GPIO_V2_LINE_FLAG_OUTPUT)
+
+#define GPIO_V2_LINE_DRIVE_FLAGS \
+	(GPIO_V2_LINE_FLAG_OPEN_DRAIN | \
+	 GPIO_V2_LINE_FLAG_OPEN_SOURCE)
+
+#define GPIO_V2_LINE_EDGE_FLAGS \
+	(GPIO_V2_LINE_FLAG_EDGE_RISING | \
+	 GPIO_V2_LINE_FLAG_EDGE_FALLING)
+
+#define GPIO_V2_LINE_VALID_FLAGS \
+	(GPIO_V2_LINE_FLAG_ACTIVE_LOW | \
+	 GPIO_V2_LINE_DIRECTION_FLAGS | \
+	 GPIO_V2_LINE_DRIVE_FLAGS | \
+	 GPIO_V2_LINE_EDGE_FLAGS | \
+	 GPIO_V2_LINE_BIAS_FLAGS)
+
+static void linereq_put_event(struct linereq *lr,
+			      struct gpio_v2_line_event *le)
+{
+	bool overflow = false;
+
+	spin_lock(&lr->wait.lock);
+	if (kfifo_is_full(&lr->events)) {
+		overflow = true;
+		kfifo_skip(&lr->events);
+	}
+	kfifo_in(&lr->events, le, 1);
+	spin_unlock(&lr->wait.lock);
+	if (!overflow)
+		wake_up_poll(&lr->wait, EPOLLIN);
+	else
+		pr_debug_ratelimited("event FIFO is full - event dropped\n");
+}
+
+static irqreturn_t edge_irq_thread(int irq, void *p)
+{
+	struct line *line = p;
+	struct linereq *lr = line->req;
+	struct gpio_v2_line_event le;
+
+	/* Do not leak kernel stack to userspace */
+	memset(&le, 0, sizeof(le));
+
+	if (line->timestamp_ns) {
+		le.timestamp_ns = line->timestamp_ns;
+	} else {
+		/*
+		 * We may be running from a nested threaded interrupt in
+		 * which case we didn't get the timestamp from
+		 * edge_irq_handler().
+		 */
+		le.timestamp_ns = ktime_get_ns();
+		if (lr->num_lines != 1)
+			line->req_seqno = atomic_inc_return(&lr->seqno);
+	}
+	line->timestamp_ns = 0;
+
+	if (line->eflags == (GPIO_V2_LINE_FLAG_EDGE_RISING |
+			     GPIO_V2_LINE_FLAG_EDGE_FALLING)) {
+		int level = gpiod_get_value_cansleep(line->desc);
+
+		if (level)
+			/* Emit low-to-high event */
+			le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
+		else
+			/* Emit high-to-low event */
+			le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
+	} else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) {
+		/* Emit low-to-high event */
+		le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
+	} else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) {
+		/* Emit high-to-low event */
+		le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
+	} else {
+		return IRQ_NONE;
+	}
+	line->line_seqno++;
+	le.line_seqno = line->line_seqno;
+	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;
+	le.offset = gpio_chip_hwgpio(line->desc);
+
+	linereq_put_event(lr, &le);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t edge_irq_handler(int irq, void *p)
+{
+	struct line *line = p;
+	struct linereq *lr = line->req;
+
+	/*
+	 * Just store the timestamp in hardirq context so we get it as
+	 * close in time as possible to the actual event.
+	 */
+	line->timestamp_ns = ktime_get_ns();
+
+	if (lr->num_lines != 1)
+		line->req_seqno = atomic_inc_return(&lr->seqno);
+
+	return IRQ_WAKE_THREAD;
+}
+
+/*
+ * returns the current debounced logical value.
+ */
+static bool debounced_value(struct line *line)
+{
+	bool value;
+
+	/*
+	 * minor race - debouncer may be stopped here, so edge_detector_stop()
+	 * must leave the value unchanged so the following will read the level
+	 * from when the debouncer was last running.
+	 */
+	value = READ_ONCE(line->level);
+
+	if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))
+		value = !value;
+
+	return value;
+}
+
+static irqreturn_t debounce_irq_handler(int irq, void *p)
+{
+	struct line *line = p;
+
+	mod_delayed_work(system_wq, &line->work,
+		usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us)));
+
+	return IRQ_HANDLED;
+}
+
+static void debounce_work_func(struct work_struct *work)
+{
+	struct gpio_v2_line_event le;
+	struct line *line = container_of(work, struct line, work.work);
+	struct linereq *lr;
+	int level;
+
+	level = gpiod_get_raw_value_cansleep(line->desc);
+	if (level < 0) {
+		pr_debug_ratelimited("debouncer failed to read line value\n");
+		return;
+	}
+
+	if (READ_ONCE(line->level) == level)
+		return;
+
+	WRITE_ONCE(line->level, level);
+
+	/* -- edge detection -- */
+	if (!line->eflags)
+		return;
+
+	/* switch from physical level to logical - if they differ */
+	if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))
+		level = !level;
+
+	/* ignore edges that are not being monitored */
+	if (((line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) ||
+	    ((line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level))
+		return;
+
+	/* Do not leak kernel stack to userspace */
+	memset(&le, 0, sizeof(le));
+
+	lr = line->req;
+	le.timestamp_ns = ktime_get_ns();
+	le.offset = gpio_chip_hwgpio(line->desc);
+	line->line_seqno++;
+	le.line_seqno = line->line_seqno;
+	le.seqno = (lr->num_lines == 1) ?
+		le.line_seqno : atomic_inc_return(&lr->seqno);
+
+	if (level)
+		/* Emit low-to-high event */
+		le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
+	else
+		/* Emit high-to-low event */
+		le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
+
+	linereq_put_event(lr, &le);
+}
+
+static int debounce_setup(struct line *line,
+			  unsigned int debounce_period_us)
+{
+	unsigned long irqflags;
+	int ret, level, irq;
+
+	/* try hardware */
+	ret = gpiod_set_debounce(line->desc, debounce_period_us);
+	if (!ret) {
+		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
+		return ret;
+	}
+	if (ret != -ENOTSUPP)
+		return ret;
+
+	if (debounce_period_us) {
+		/* setup software debounce */
+		level = gpiod_get_raw_value_cansleep(line->desc);
+		if (level < 0)
+			return level;
+
+		irq = gpiod_to_irq(line->desc);
+		if (irq < 0)
+			return -ENXIO;
+
+		WRITE_ONCE(line->level, level);
+		irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
+		ret = request_irq(irq, debounce_irq_handler, irqflags,
+				  line->req->label, line);
+		if (ret)
+			return ret;
+
+		WRITE_ONCE(line->sw_debounced, 1);
+		line->irq = irq;
+	}
+	return 0;
+}
+
+static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc,
+					  unsigned int line_idx)
+{
+	unsigned int i;
+	u64 mask = BIT_ULL(line_idx);
+
+	for (i = 0; i < lc->num_attrs; i++) {
+		if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) &&
+		    (lc->attrs[i].mask & mask))
+			return true;
+	}
+	return false;
+}
+
+static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc,
+					       unsigned int line_idx)
+{
+	unsigned int i;
+	u64 mask = BIT_ULL(line_idx);
+
+	for (i = 0; i < lc->num_attrs; i++) {
+		if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) &&
+		    (lc->attrs[i].mask & mask))
+			return lc->attrs[i].attr.debounce_period_us;
+	}
+	return 0;
+}
+
+static void edge_detector_stop(struct line *line)
+{
+	if (line->irq) {
+		free_irq(line->irq, line);
+		line->irq = 0;
+	}
+
+	cancel_delayed_work_sync(&line->work);
+	WRITE_ONCE(line->sw_debounced, 0);
+	line->eflags = 0;
+	/* do not change line->level - see comment in debounced_value() */
+}
+
+static int edge_detector_setup(struct line *line,
+			       struct gpio_v2_line_config *lc,
+			       unsigned int line_idx,
+			       u64 eflags)
+{
+	u32 debounce_period_us;
+	unsigned long irqflags = 0;
+	int irq, ret;
+
+	if (eflags && !kfifo_initialized(&line->req->events)) {
+		ret = kfifo_alloc(&line->req->events,
+				  line->req->event_buffer_size, GFP_KERNEL);
+		if (ret)
+			return ret;
+	}
+	line->eflags = eflags;
+	if (gpio_v2_line_config_debounced(lc, line_idx)) {
+		debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx);
+		ret = debounce_setup(line, debounce_period_us);
+		if (ret)
+			return ret;
+		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
+	}
+
+	/* detection disabled or sw debouncer will provide edge detection */
+	if (!eflags || READ_ONCE(line->sw_debounced))
+		return 0;
+
+	irq = gpiod_to_irq(line->desc);
+	if (irq < 0)
+		return -ENXIO;
+
+	if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING)
+		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?
+			IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
+	if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING)
+		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?
+			IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
+	irqflags |= IRQF_ONESHOT;
+
+	/* Request a thread to read the events */
+	ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread,
+				   irqflags, line->req->label, line);
+	if (ret)
+		return ret;
+
+	line->irq = irq;
+	return 0;
+}
+
+static int edge_detector_update(struct line *line,
+				struct gpio_v2_line_config *lc,
+				unsigned int line_idx,
+				u64 eflags, bool polarity_change)
+{
+	unsigned int debounce_period_us =
+		gpio_v2_line_config_debounce_period(lc, line_idx);
+
+	if ((line->eflags == eflags) && !polarity_change &&
+	    (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us))
+		return 0;
+
+	/* sw debounced and still will be...*/
+	if (debounce_period_us && READ_ONCE(line->sw_debounced)) {
+		line->eflags = eflags;
+		WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
+		return 0;
+	}
+
+	/* reconfiguring edge detection or sw debounce being disabled */
+	if ((line->irq && !READ_ONCE(line->sw_debounced)) ||
+	    (!debounce_period_us && READ_ONCE(line->sw_debounced)))
+		edge_detector_stop(line);
+
+	return edge_detector_setup(line, lc, line_idx, eflags);
+}
+
+static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc,
+				     unsigned int line_idx)
+{
+	unsigned int i;
+	u64 mask = BIT_ULL(line_idx);
+
+	for (i = 0; i < lc->num_attrs; i++) {
+		if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) &&
+		    (lc->attrs[i].mask & mask))
+			return lc->attrs[i].attr.flags;
+	}
+	return lc->flags;
+}
+
+static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc,
+					    unsigned int line_idx)
+{
+	unsigned int i;
+	u64 mask = BIT_ULL(line_idx);
+
+	for (i = 0; i < lc->num_attrs; i++) {
+		if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) &&
+		    (lc->attrs[i].mask & mask))
+			return !!(lc->attrs[i].attr.values & mask);
+	}
+	return 0;
+}
+
+static int gpio_v2_line_flags_validate(u64 flags)
+{
+	/* Return an error if an unknown flag is set */
+	if (flags & ~GPIO_V2_LINE_VALID_FLAGS)
+		return -EINVAL;
+
+	/*
+	 * Do not allow both INPUT and OUTPUT flags to be set as they are
+	 * contradictory.
+	 */
+	if ((flags & GPIO_V2_LINE_FLAG_INPUT) &&
+	    (flags & GPIO_V2_LINE_FLAG_OUTPUT))
+		return -EINVAL;
+
+	/* Edge detection requires explicit input. */
+	if ((flags & GPIO_V2_LINE_EDGE_FLAGS) &&
+	    !(flags & GPIO_V2_LINE_FLAG_INPUT))
+		return -EINVAL;
+
+	/*
+	 * Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single
+	 * request. If the hardware actually supports enabling both at the
+	 * same time the electrical result would be disastrous.
+	 */
+	if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) &&
+	    (flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE))
+		return -EINVAL;
+
+	/* Drive requires explicit output direction. */
+	if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) &&
+	    !(flags & GPIO_V2_LINE_FLAG_OUTPUT))
+		return -EINVAL;
+
+	/* Bias requires explicit direction. */
+	if ((flags & GPIO_V2_LINE_BIAS_FLAGS) &&
+	    !(flags & GPIO_V2_LINE_DIRECTION_FLAGS))
+		return -EINVAL;
+
+	/* Only one bias flag can be set. */
+	if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) &&
+	     (flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN |
+		       GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) ||
+	    ((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) &&
+	     (flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP)))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc,
+					unsigned int num_lines)
+{
+	unsigned int i;
+	u64 flags;
+	int ret;
+
+	if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX)
+		return -EINVAL;
+
+	if (memchr_inv(lc->padding, 0, sizeof(lc->padding)))
+		return -EINVAL;
+
+	for (i = 0; i < num_lines; i++) {
+		flags = gpio_v2_line_config_flags(lc, i);
+		ret = gpio_v2_line_flags_validate(flags);
+		if (ret)
+			return ret;
+
+		/* debounce requires explicit input */
+		if (gpio_v2_line_config_debounced(lc, i) &&
+		    !(flags & GPIO_V2_LINE_FLAG_INPUT))
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static void gpio_v2_line_config_flags_to_desc_flags(u64 flags,
+						    unsigned long *flagsp)
+{
+	assign_bit(FLAG_ACTIVE_LOW, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW);
+
+	if (flags & GPIO_V2_LINE_FLAG_OUTPUT)
+		set_bit(FLAG_IS_OUT, flagsp);
+	else if (flags & GPIO_V2_LINE_FLAG_INPUT)
+		clear_bit(FLAG_IS_OUT, flagsp);
+
+	assign_bit(FLAG_EDGE_RISING, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_EDGE_RISING);
+	assign_bit(FLAG_EDGE_FALLING, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_EDGE_FALLING);
+
+	assign_bit(FLAG_OPEN_DRAIN, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN);
+	assign_bit(FLAG_OPEN_SOURCE, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE);
+
+	assign_bit(FLAG_PULL_UP, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP);
+	assign_bit(FLAG_PULL_DOWN, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN);
+	assign_bit(FLAG_BIAS_DISABLE, flagsp,
+		   flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED);
+}
+
+static long linereq_get_values(struct linereq *lr, void __user *ip)
+{
+	struct gpio_v2_line_values lv;
+	DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
+	struct gpio_desc **descs;
+	unsigned int i, didx, num_get;
+	bool val;
+	int ret;
+
+	/* NOTE: It's ok to read values of output lines. */
+	if (copy_from_user(&lv, ip, sizeof(lv)))
+		return -EFAULT;
+
+	for (num_get = 0, i = 0; i < lr->num_lines; i++) {
+		if (lv.mask & BIT_ULL(i)) {
+			num_get++;
+			descs = &lr->lines[i].desc;
+		}
+	}
+
+	if (num_get == 0)
+		return -EINVAL;
+
+	if (num_get != 1) {
+		descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL);
+		if (!descs)
+			return -ENOMEM;
+		for (didx = 0, i = 0; i < lr->num_lines; i++) {
+			if (lv.mask & BIT_ULL(i)) {
+				descs[didx] = lr->lines[i].desc;
+				didx++;
+			}
+		}
+	}
+	ret = gpiod_get_array_value_complex(false, true, num_get,
+					    descs, NULL, vals);
+
+	if (num_get != 1)
+		kfree(descs);
+	if (ret)
+		return ret;
+
+	lv.bits = 0;
+	for (didx = 0, i = 0; i < lr->num_lines; i++) {
+		if (lv.mask & BIT_ULL(i)) {
+			if (lr->lines[i].sw_debounced)
+				val = debounced_value(&lr->lines[i]);
+			else
+				val = test_bit(didx, vals);
+			if (val)
+				lv.bits |= BIT_ULL(i);
+			didx++;
+		}
+	}
+
+	if (copy_to_user(ip, &lv, sizeof(lv)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long linereq_set_values_unlocked(struct linereq *lr,
+					struct gpio_v2_line_values *lv)
+{
+	DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
+	struct gpio_desc **descs;
+	unsigned int i, didx, num_set;
+	int ret;
+
+	bitmap_zero(vals, GPIO_V2_LINES_MAX);
+	for (num_set = 0, i = 0; i < lr->num_lines; i++) {
+		if (lv->mask & BIT_ULL(i)) {
+			if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags))
+				return -EPERM;
+			if (lv->bits & BIT_ULL(i))
+				__set_bit(num_set, vals);
+			num_set++;
+			descs = &lr->lines[i].desc;
+		}
+	}
+	if (num_set == 0)
+		return -EINVAL;
+
+	if (num_set != 1) {
+		/* build compacted desc array and values */
+		descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL);
+		if (!descs)
+			return -ENOMEM;
+		for (didx = 0, i = 0; i < lr->num_lines; i++) {
+			if (lv->mask & BIT_ULL(i)) {
+				descs[didx] = lr->lines[i].desc;
+				didx++;
+			}
+		}
+	}
+	ret = gpiod_set_array_value_complex(false, true, num_set,
+					    descs, NULL, vals);
+
+	if (num_set != 1)
+		kfree(descs);
+	return ret;
+}
+
+static long linereq_set_values(struct linereq *lr, void __user *ip)
+{
+	struct gpio_v2_line_values lv;
+	int ret;
+
+	if (copy_from_user(&lv, ip, sizeof(lv)))
+		return -EFAULT;
+
+	mutex_lock(&lr->config_mutex);
+
+	ret = linereq_set_values_unlocked(lr, &lv);
+
+	mutex_unlock(&lr->config_mutex);
+
+	return ret;
+}
+
+static long linereq_set_config_unlocked(struct linereq *lr,
+					struct gpio_v2_line_config *lc)
+{
+	struct gpio_desc *desc;
+	unsigned int i;
+	u64 flags;
+	bool polarity_change;
+	int ret;
+
+	for (i = 0; i < lr->num_lines; i++) {
+		desc = lr->lines[i].desc;
+		flags = gpio_v2_line_config_flags(lc, i);
+		polarity_change =
+			(!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) !=
+			 ((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0));
+
+		gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
+		/*
+		 * Lines have to be requested explicitly for input
+		 * or output, else the line will be treated "as is".
+		 */
+		if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
+			int val = gpio_v2_line_config_output_value(lc, i);
+
+			edge_detector_stop(&lr->lines[i]);
+			ret = gpiod_direction_output(desc, val);
+			if (ret)
+				return ret;
+		} else if (flags & GPIO_V2_LINE_FLAG_INPUT) {
+			ret = gpiod_direction_input(desc);
+			if (ret)
+				return ret;
+
+			ret = edge_detector_update(&lr->lines[i], lc, i,
+					flags & GPIO_V2_LINE_EDGE_FLAGS,
+					polarity_change);
+			if (ret)
+				return ret;
+		}
+
+		blocking_notifier_call_chain(&desc->gdev->notifier,
+					     GPIO_V2_LINE_CHANGED_CONFIG,
+					     desc);
+	}
+	return 0;
+}
+
+static long linereq_set_config(struct linereq *lr, void __user *ip)
+{
+	struct gpio_v2_line_config lc;
+	int ret;
+
+	if (copy_from_user(&lc, ip, sizeof(lc)))
+		return -EFAULT;
+
+	ret = gpio_v2_line_config_validate(&lc, lr->num_lines);
+	if (ret)
+		return ret;
+
+	mutex_lock(&lr->config_mutex);
+
+	ret = linereq_set_config_unlocked(lr, &lc);
+
+	mutex_unlock(&lr->config_mutex);
+
+	return ret;
+}
+
+static long linereq_ioctl(struct file *file, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct linereq *lr = file->private_data;
+	void __user *ip = (void __user *)arg;
+
+	if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL)
+		return linereq_get_values(lr, ip);
+	else if (cmd == GPIO_V2_LINE_SET_VALUES_IOCTL)
+		return linereq_set_values(lr, ip);
+	else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL)
+		return linereq_set_config(lr, ip);
+
+	return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
+				 unsigned long arg)
+{
+	return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static __poll_t linereq_poll(struct file *file,
+			    struct poll_table_struct *wait)
+{
+	struct linereq *lr = file->private_data;
+	__poll_t events = 0;
+
+	poll_wait(file, &lr->wait, wait);
+
+	if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events,
+						 &lr->wait.lock))
+		events = EPOLLIN | EPOLLRDNORM;
+
+	return events;
+}
+
+static ssize_t linereq_read(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 (count < sizeof(le))
+		return -EINVAL;
+
+	do {
+		spin_lock(&lr->wait.lock);
+		if (kfifo_is_empty(&lr->events)) {
+			if (bytes_read) {
+				spin_unlock(&lr->wait.lock);
+				return bytes_read;
+			}
+
+			if (file->f_flags & O_NONBLOCK) {
+				spin_unlock(&lr->wait.lock);
+				return -EAGAIN;
+			}
+
+			ret = wait_event_interruptible_locked(lr->wait,
+					!kfifo_is_empty(&lr->events));
+			if (ret) {
+				spin_unlock(&lr->wait.lock);
+				return ret;
+			}
+		}
+
+		ret = kfifo_out(&lr->events, &le, 1);
+		spin_unlock(&lr->wait.lock);
+		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 (copy_to_user(buf + bytes_read, &le, sizeof(le)))
+			return -EFAULT;
+		bytes_read += sizeof(le);
+	} while (count >= bytes_read + sizeof(le));
+
+	return bytes_read;
+}
+
+static void linereq_free(struct linereq *lr)
+{
+	unsigned int i;
+
+	for (i = 0; i < lr->num_lines; i++) {
+		edge_detector_stop(&lr->lines[i]);
+		if (lr->lines[i].desc)
+			gpiod_free(lr->lines[i].desc);
+	}
+	kfifo_free(&lr->events);
+	kfree(lr->label);
+	put_device(&lr->gdev->dev);
+	kfree(lr);
+}
+
+static int linereq_release(struct inode *inode, struct file *file)
+{
+	struct linereq *lr = file->private_data;
+
+	linereq_free(lr);
+	return 0;
+}
+
+static const struct file_operations line_fileops = {
+	.release = linereq_release,
+	.read = linereq_read,
+	.poll = linereq_poll,
+	.owner = THIS_MODULE,
+	.llseek = noop_llseek,
+	.unlocked_ioctl = linereq_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = linereq_ioctl_compat,
+#endif
+};
+
+static int linereq_create(struct gpio_device *gdev, void __user *ip)
+{
+	struct gpio_v2_line_request ulr;
+	struct gpio_v2_line_config *lc;
+	struct linereq *lr;
+	struct file *file;
+	u64 flags;
+	unsigned int i;
+	int fd, ret;
+
+	if (copy_from_user(&ulr, ip, sizeof(ulr)))
+		return -EFAULT;
+
+	if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX))
+		return -EINVAL;
+
+	if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding)))
+		return -EINVAL;
+
+	lc = &ulr.config;
+	ret = gpio_v2_line_config_validate(lc, ulr.num_lines);
+	if (ret)
+		return ret;
+
+	lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL);
+	if (!lr)
+		return -ENOMEM;
+
+	lr->gdev = gdev;
+	get_device(&gdev->dev);
+
+	for (i = 0; i < ulr.num_lines; i++) {
+		lr->lines[i].req = lr;
+		WRITE_ONCE(lr->lines[i].sw_debounced, 0);
+		INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func);
+	}
+
+	if (ulr.consumer[0] != '\0') {
+		/* label is only initialized if consumer is set */
+		lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1,
+				     GFP_KERNEL);
+		if (!lr->label) {
+			ret = -ENOMEM;
+			goto out_free_linereq;
+		}
+	}
+
+	mutex_init(&lr->config_mutex);
+	init_waitqueue_head(&lr->wait);
+	lr->event_buffer_size = ulr.event_buffer_size;
+	if (lr->event_buffer_size == 0)
+		lr->event_buffer_size = ulr.num_lines * 16;
+	else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16)
+		lr->event_buffer_size = GPIO_V2_LINES_MAX * 16;
+
+	atomic_set(&lr->seqno, 0);
+	lr->num_lines = ulr.num_lines;
+
+	/* Request each GPIO */
+	for (i = 0; i < ulr.num_lines; i++) {
+		u32 offset = ulr.offsets[i];
+		struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset);
+
+		if (IS_ERR(desc)) {
+			ret = PTR_ERR(desc);
+			goto out_free_linereq;
+		}
+
+		ret = gpiod_request(desc, lr->label);
+		if (ret)
+			goto out_free_linereq;
+
+		lr->lines[i].desc = desc;
+		flags = gpio_v2_line_config_flags(lc, i);
+		gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
+
+		ret = gpiod_set_transitory(desc, false);
+		if (ret < 0)
+			goto out_free_linereq;
+
+		/*
+		 * Lines have to be requested explicitly for input
+		 * or output, else the line will be treated "as is".
+		 */
+		if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
+			int val = gpio_v2_line_config_output_value(lc, i);
+
+			ret = gpiod_direction_output(desc, val);
+			if (ret)
+				goto out_free_linereq;
+		} else if (flags & GPIO_V2_LINE_FLAG_INPUT) {
+			ret = gpiod_direction_input(desc);
+			if (ret)
+				goto out_free_linereq;
+
+			ret = edge_detector_setup(&lr->lines[i], lc, i,
+					flags & GPIO_V2_LINE_EDGE_FLAGS);
+			if (ret)
+				goto out_free_linereq;
+		}
+
+		blocking_notifier_call_chain(&desc->gdev->notifier,
+					     GPIO_V2_LINE_CHANGED_REQUESTED, desc);
+
+		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
+			offset);
+	}
+
+	fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
+	if (fd < 0) {
+		ret = fd;
+		goto out_free_linereq;
+	}
+
+	file = anon_inode_getfile("gpio-line", &line_fileops, lr,
+				  O_RDONLY | O_CLOEXEC);
+	if (IS_ERR(file)) {
+		ret = PTR_ERR(file);
+		goto out_put_unused_fd;
+	}
+
+	ulr.fd = fd;
+	if (copy_to_user(ip, &ulr, sizeof(ulr))) {
+		/*
+		 * fput() will trigger the release() callback, so do not go onto
+		 * the regular error cleanup path here.
+		 */
+		fput(file);
+		put_unused_fd(fd);
+		return -EFAULT;
+	}
+
+	fd_install(fd, file);
+
+	dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
+		lr->num_lines);
+
+	return 0;
+
+out_put_unused_fd:
+	put_unused_fd(fd);
+out_free_linereq:
+	linereq_free(lr);
+	return ret;
+}
+
+#ifdef CONFIG_GPIO_CDEV_V1
 
 /*
  * GPIO line event management
@@ -680,11 +1736,11 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	le->gdev = gdev;
 	get_device(&gdev->dev);
 
-	/* Make sure this is terminated */
-	eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
-	if (strlen(eventreq.consumer_label)) {
-		le->label = kstrdup(eventreq.consumer_label,
-				    GFP_KERNEL);
+	if (eventreq.consumer_label[0] != '\0') {
+		/* label is only initialized if consumer_label is set */
+		le->label = kstrndup(eventreq.consumer_label,
+				     sizeof(eventreq.consumer_label) - 1,
+				     GFP_KERNEL);
 		if (!le->label) {
 			ret = -ENOMEM;
 			goto out_free_le;
@@ -704,7 +1760,7 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 		goto out_free_le;
 
 	blocking_notifier_call_chain(&desc->gdev->notifier,
-				     GPIOLINE_CHANGED_REQUESTED, desc);
+				     GPIO_V2_LINE_CHANGED_REQUESTED, desc);
 
 	irq = gpiod_to_irq(desc);
 	if (irq <= 0) {
@@ -771,12 +1827,60 @@ out_free_le:
 	return ret;
 }
 
+static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2,
+				    struct gpioline_info *info_v1)
+{
+	u64 flagsv2 = info_v2->flags;
+
+	memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name));
+	memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer));
+	info_v1->line_offset = info_v2->offset;
+	info_v1->flags = 0;
+
+	if (flagsv2 & GPIO_V2_LINE_FLAG_USED)
+		info_v1->flags |= GPIOLINE_FLAG_KERNEL;
+
+	if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT)
+		info_v1->flags |= GPIOLINE_FLAG_IS_OUT;
+
+	if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW)
+		info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW;
+
+	if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN)
+		info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN;
+	if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE)
+		info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE;
+
+	if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP)
+		info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
+	if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN)
+		info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
+	if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED)
+		info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE;
+}
+
+static void gpio_v2_line_info_changed_to_v1(
+		struct gpio_v2_line_info_changed *lic_v2,
+		struct gpioline_info_changed *lic_v1)
+{
+	gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info);
+	lic_v1->timestamp = lic_v2->timestamp_ns;
+	lic_v1->event_type = lic_v2->event_type;
+}
+
+#endif /* CONFIG_GPIO_CDEV_V1 */
+
 static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
-				  struct gpioline_info *info)
+				  struct gpio_v2_line_info *info)
 {
 	struct gpio_chip *gc = desc->gdev->chip;
 	bool ok_for_pinctrl;
 	unsigned long flags;
+	u32 debounce_period_us;
+	unsigned int num_attrs = 0;
+
+	memset(info, 0, sizeof(*info));
+	info->offset = gpio_chip_hwgpio(desc);
 
 	/*
 	 * This function takes a mutex so we must check this before taking
@@ -786,23 +1890,15 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 	 * lock common to both frameworks?
 	 */
 	ok_for_pinctrl =
-		pinctrl_gpio_can_use_line(gc->base + info->line_offset);
+		pinctrl_gpio_can_use_line(gc->base + info->offset);
 
 	spin_lock_irqsave(&gpio_lock, flags);
 
-	if (desc->name) {
-		strncpy(info->name, desc->name, sizeof(info->name));
-		info->name[sizeof(info->name) - 1] = '\0';
-	} else {
-		info->name[0] = '\0';
-	}
+	if (desc->name)
+		strscpy(info->name, desc->name, sizeof(info->name));
 
-	if (desc->label) {
-		strncpy(info->consumer, desc->label, sizeof(info->consumer));
-		info->consumer[sizeof(info->consumer) - 1] = '\0';
-	} else {
-		info->consumer[0] = '\0';
-	}
+	if (desc->label)
+		strscpy(info->consumer, desc->label, sizeof(info->consumer));
 
 	/*
 	 * Userspace only need to know that the kernel is using this GPIO so
@@ -815,23 +1911,40 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 	    test_bit(FLAG_EXPORT, &desc->flags) ||
 	    test_bit(FLAG_SYSFS, &desc->flags) ||
 	    !ok_for_pinctrl)
-		info->flags |= GPIOLINE_FLAG_KERNEL;
+		info->flags |= GPIO_V2_LINE_FLAG_USED;
+
 	if (test_bit(FLAG_IS_OUT, &desc->flags))
-		info->flags |= GPIOLINE_FLAG_IS_OUT;
+		info->flags |= GPIO_V2_LINE_FLAG_OUTPUT;
+	else
+		info->flags |= GPIO_V2_LINE_FLAG_INPUT;
+
 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
-		info->flags |= GPIOLINE_FLAG_ACTIVE_LOW;
+		info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW;
+
 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
-		info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
-				GPIOLINE_FLAG_IS_OUT);
+		info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN;
 	if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
-		info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
-				GPIOLINE_FLAG_IS_OUT);
+		info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE;
+
 	if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
-		info->flags |= GPIOLINE_FLAG_BIAS_DISABLE;
+		info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED;
 	if (test_bit(FLAG_PULL_DOWN, &desc->flags))
-		info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
+		info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN;
 	if (test_bit(FLAG_PULL_UP, &desc->flags))
-		info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
+		info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP;
+
+	if (test_bit(FLAG_EDGE_RISING, &desc->flags))
+		info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING;
+	if (test_bit(FLAG_EDGE_FALLING, &desc->flags))
+		info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING;
+
+	debounce_period_us = READ_ONCE(desc->debounce_period_us);
+	if (debounce_period_us) {
+		info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
+		info->attrs[num_attrs].debounce_period_us = debounce_period_us;
+		num_attrs++;
+	}
+	info->num_attrs = num_attrs;
 
 	spin_unlock_irqrestore(&gpio_lock, flags);
 }
@@ -839,11 +1952,65 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
 struct gpio_chardev_data {
 	struct gpio_device *gdev;
 	wait_queue_head_t wait;
-	DECLARE_KFIFO(events, struct gpioline_info_changed, 32);
+	DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32);
 	struct notifier_block lineinfo_changed_nb;
 	unsigned long *watched_lines;
+#ifdef CONFIG_GPIO_CDEV_V1
+	atomic_t watch_abi_version;
+#endif
 };
 
+#ifdef CONFIG_GPIO_CDEV_V1
+/*
+ * returns 0 if the versions match, else the previously selected ABI version
+ */
+static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata,
+				       unsigned int version)
+{
+	int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version);
+
+	if (abiv == version)
+		return 0;
+
+	return abiv;
+}
+#endif
+
+static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
+			bool watch)
+{
+	struct gpio_desc *desc;
+	struct gpio_v2_line_info lineinfo;
+
+	if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
+		return -EFAULT;
+
+	if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding)))
+		return -EINVAL;
+
+	desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.offset);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	if (watch) {
+#ifdef CONFIG_GPIO_CDEV_V1
+		if (lineinfo_ensure_abi_version(cdev, 2))
+			return -EPERM;
+#endif
+		if (test_and_set_bit(lineinfo.offset, cdev->watched_lines))
+			return -EBUSY;
+	}
+	gpio_desc_to_lineinfo(desc, &lineinfo);
+
+	if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
+		if (watch)
+			clear_bit(lineinfo.offset, cdev->watched_lines);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
 /*
  * gpio_ioctl() - ioctl handler for the GPIO chardev
  */
@@ -853,7 +2020,6 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	struct gpio_device *gdev = cdev->gdev;
 	struct gpio_chip *gc = gdev->chip;
 	void __user *ip = (void __user *)arg;
-	struct gpio_desc *desc;
 	__u32 offset;
 
 	/* We fail any subsequent ioctl():s when the chip is gone */
@@ -866,18 +2032,19 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 		memset(&chipinfo, 0, sizeof(chipinfo));
 
-		strncpy(chipinfo.name, dev_name(&gdev->dev),
+		strscpy(chipinfo.name, dev_name(&gdev->dev),
 			sizeof(chipinfo.name));
-		chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
-		strncpy(chipinfo.label, gdev->label,
+		strscpy(chipinfo.label, gdev->label,
 			sizeof(chipinfo.label));
-		chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
 		chipinfo.lines = gdev->ngpio;
 		if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
 			return -EFAULT;
 		return 0;
+#ifdef CONFIG_GPIO_CDEV_V1
 	} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
+		struct gpio_desc *desc;
 		struct gpioline_info lineinfo;
+		struct gpio_v2_line_info lineinfo_v2;
 
 		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
 			return -EFAULT;
@@ -887,7 +2054,8 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (IS_ERR(desc))
 			return PTR_ERR(desc);
 
-		gpio_desc_to_lineinfo(desc, &lineinfo);
+		gpio_desc_to_lineinfo(desc, &lineinfo_v2);
+		gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
 
 		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
 			return -EFAULT;
@@ -897,7 +2065,9 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
 		return lineevent_create(gdev, ip);
 	} else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
+		struct gpio_desc *desc;
 		struct gpioline_info lineinfo;
+		struct gpio_v2_line_info lineinfo_v2;
 
 		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
 			return -EFAULT;
@@ -907,10 +2077,14 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (IS_ERR(desc))
 			return PTR_ERR(desc);
 
+		if (lineinfo_ensure_abi_version(cdev, 1))
+			return -EPERM;
+
 		if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines))
 			return -EBUSY;
 
-		gpio_desc_to_lineinfo(desc, &lineinfo);
+		gpio_desc_to_lineinfo(desc, &lineinfo_v2);
+		gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
 
 		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
 			clear_bit(lineinfo.line_offset, cdev->watched_lines);
@@ -918,6 +2092,13 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		}
 
 		return 0;
+#endif /* CONFIG_GPIO_CDEV_V1 */
+	} else if (cmd == GPIO_V2_GET_LINEINFO_IOCTL ||
+		   cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL) {
+		return lineinfo_get(cdev, ip,
+				    cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL);
+	} else if (cmd == GPIO_V2_GET_LINE_IOCTL) {
+		return linereq_create(gdev, ip);
 	} else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) {
 		if (copy_from_user(&offset, ip, sizeof(offset)))
 			return -EFAULT;
@@ -951,7 +2132,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
 				   unsigned long action, void *data)
 {
 	struct gpio_chardev_data *cdev = to_gpio_chardev_data(nb);
-	struct gpioline_info_changed chg;
+	struct gpio_v2_line_info_changed chg;
 	struct gpio_desc *desc = data;
 	int ret;
 
@@ -959,9 +2140,8 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
 		return NOTIFY_DONE;
 
 	memset(&chg, 0, sizeof(chg));
-	chg.info.line_offset = gpio_chip_hwgpio(desc);
 	chg.event_type = action;
-	chg.timestamp = ktime_get_ns();
+	chg.timestamp_ns = ktime_get_ns();
 	gpio_desc_to_lineinfo(desc, &chg.info);
 
 	ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock);
@@ -992,12 +2172,16 @@ 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;
-	struct gpioline_info_changed event;
+	struct gpio_v2_line_info_changed event;
 	ssize_t bytes_read = 0;
 	int ret;
+	size_t event_size;
 
-	if (count < sizeof(event))
+#ifndef CONFIG_GPIO_CDEV_V1
+	event_size = sizeof(struct gpio_v2_line_info_changed);
+	if (count < event_size)
 		return -EINVAL;
+#endif
 
 	do {
 		spin_lock(&cdev->wait.lock);
@@ -1019,7 +2203,17 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
 				return ret;
 			}
 		}
-
+#ifdef CONFIG_GPIO_CDEV_V1
+		/* must be after kfifo check so watch_abi_version is set */
+		if (atomic_read(&cdev->watch_abi_version) == 2)
+			event_size = sizeof(struct gpio_v2_line_info_changed);
+		else
+			event_size = sizeof(struct gpioline_info_changed);
+		if (count < event_size) {
+			spin_unlock(&cdev->wait.lock);
+			return -EINVAL;
+		}
+#endif
 		ret = kfifo_out(&cdev->events, &event, 1);
 		spin_unlock(&cdev->wait.lock);
 		if (ret != 1) {
@@ -1028,9 +2222,23 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
 			/* We should never get here. See lineevent_read(). */
 		}
 
-		if (copy_to_user(buf + bytes_read, &event, sizeof(event)))
+#ifdef CONFIG_GPIO_CDEV_V1
+		if (event_size == sizeof(struct gpio_v2_line_info_changed)) {
+			if (copy_to_user(buf + bytes_read, &event, event_size))
+				return -EFAULT;
+		} else {
+			struct gpioline_info_changed event_v1;
+
+			gpio_v2_line_info_changed_to_v1(&event, &event_v1);
+			if (copy_to_user(buf + bytes_read, &event_v1,
+					 event_size))
+				return -EFAULT;
+		}
+#else
+		if (copy_to_user(buf + bytes_read, &event, event_size))
 			return -EFAULT;
-		bytes_read += sizeof(event);
+#endif
+		bytes_read += event_size;
 	} while (count >= bytes_read + sizeof(event));
 
 	return bytes_read;