Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "Here is the bulk of GPIO changes for v4.5.

  Notably there are big refactorings mostly by myself, aimed at getting
  the gpio_chip into a shape that makes me believe I can proceed to
  preserve state for a proper userspace ABI (character device) that has
  already been proposed once, but resulted in the feedback that I need
  to go back and restructure stuff.  So I've been restructuring stuff.
  On the way I ran into brokenness (return code from the get_value()
  callback) and had to fix it.  Also, refactored generic GPIO to be
  simpler.

  Some of that is still waiting to trickle down from the subsystems all
  over the kernel that provide random gpio_chips, I've touched every
  single GPIO driver in the kernel now, oh man I didn't know I was
  responsible for so much...

  Apart from that we're churning along as usual.

  I took some effort to test and retest so it should merge nicely and we
  shook out a couple of bugs in -next.

  Infrastructural changes:

   - In struct gpio_chip, rename the .dev node to .parent to better
     reflect the fact that this is not the GPIO struct device
     abstraction.  We will add that soon so this would be totallt
     confusing.

   - It was noted that the driver .get_value() callbacks was sometimes
     reporting negative -ERR values to the gpiolib core, expecting them
     to be propagated to consumer gpiod_get_value() and gpio_get_value()
     calls.  This was not happening, so as there was a mess of drivers
     returning negative errors and some returning "anything else than
     zero" to indicate that a line was active.  As some would have bit
     31 set to indicate "line active" it clashed with negative error
     codes.  This is fixed by the largeish series clamping values in all
     drivers with !!value to [0,1] and then augmenting the code to
     propagate error codes to consumers.  (Includes some ACKed patches
     in other subsystems.)

   - Add a void *data pointer to struct gpio_chip.  The container_of()
     design pattern is indeed very nice, but we want to reform the
     struct gpio_chip to be a non-volative, stateless business, and keep
     states internal to the gpiolib to be able to hold on to the state
     when adding a proper userspace ABI (character device) further down
     the road.  To achieve this, drivers need a handle at the internal
     state that is not dependent on their struct gpio_chip() so we add
     gpiochip_add_data() and gpiochip_get_data() following the pattern
     of many other subsystems.  All the "use gpiochip data pointer"
     patches transforms drivers to this scheme.

   - The Generic GPIO chip header has been merged into the general
     <linux/gpio/driver.h> header, and the custom header for that
     removed.  Instead of having a separate mm_gpio_chip struct for
     these generic drivers, merge that into struct gpio_chip,
     simplifying the code and removing the need for separate and
     confusing includes.

  Misc improvements:

   - Stabilize the way GPIOs are looked up from the ACPI legacy
     specification.

   - Incremental driver features for PXA, PCA953X, Lantiq (patches from
     the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48

  New drivers:

   - Add a GPIO chip to the ALSA SoC AC97 driver.

   - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
     but the branch is merged here too to account for infrastructural
     changes).

   - The sx150x driver now supports the sx1502"

* tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
  gpio: generic: make bgpio_pdata always visible
  gpiolib: fix chip order in gpio list
  gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
  gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
  gpio: brcmstb: Allow building driver for BMIPS_GENERIC
  gpio: brcmstb: Set endian flags for big-endian MIPS
  gpio: moxart: fix build regression
  gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
  leds: pca9532: use gpiochip data pointer
  leds: tca6507: use gpiochip data pointer
  hid: cp2112: use gpiochip data pointer
  bcma: gpio: use gpiochip data pointer
  avr32: gpio: use gpiochip data pointer
  video: fbdev: via: use gpiochip data pointer
  gpio: pch: Optimize pch_gpio_get()
  Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
  pinctrl: nsp-gpio: use gpiochip data pointer
  pinctrl: vt8500-wmt: use gpiochip data pointer
  pinctrl: exynos5440: use gpiochip data pointer
  pinctrl: at91-pio4: use gpiochip data pointer
  ...

1 files changed, 68 insertions, 42 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 3346abd29b52..5c1ba879f889 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -182,39 +182,62 @@ EXPORT_SYMBOL_GPL(gpiod_get_direction);
 
 /*
  * Add a new chip to the global chips list, keeping the list of chips sorted
- * by base order.
+ * by range(means [base, base + ngpio - 1]) order.
  *
  * Return -EBUSY if the new chip overlaps with some other chip's integer
  * space.
  */
 static int gpiochip_add_to_list(struct gpio_chip *chip)
 {
-	struct list_head *pos;
-	struct gpio_chip *_chip;
-	int err = 0;
+	struct gpio_chip *iterator;
+	struct gpio_chip *previous = NULL;
 
-	/* find where to insert our chip */
-	list_for_each(pos, &gpio_chips) {
-		_chip = list_entry(pos, struct gpio_chip, list);
-		/* shall we insert before _chip? */
-		if (_chip->base >= chip->base + chip->ngpio)
-			break;
+	if (list_empty(&gpio_chips)) {
+		list_add_tail(&chip->list, &gpio_chips);
+		return 0;
 	}
 
-	/* are we stepping on the chip right before? */
-	if (pos != &gpio_chips && pos->prev != &gpio_chips) {
-		_chip = list_entry(pos->prev, struct gpio_chip, list);
-		if (_chip->base + _chip->ngpio > chip->base) {
-			dev_err(chip->dev,
-			       "GPIO integer space overlap, cannot add chip\n");
-			err = -EBUSY;
+	list_for_each_entry(iterator, &gpio_chips, list) {
+		if (iterator->base >= chip->base + chip->ngpio) {
+			/*
+			 * Iterator is the first GPIO chip so there is no
+			 * previous one
+			 */
+			if (!previous) {
+				goto found;
+			} else {
+				/*
+				 * We found a valid range(means
+				 * [base, base + ngpio - 1]) between previous
+				 * and iterator chip.
+				 */
+				if (previous->base + previous->ngpio
+						<= chip->base)
+					goto found;
+			}
 		}
+		previous = iterator;
+	}
+
+	/*
+	 * We are beyond the last chip in the list and iterator now
+	 * points to the head.
+	 * Let iterator point to the last chip in the list.
+	 */
+
+	iterator = list_last_entry(&gpio_chips, struct gpio_chip, list);
+	if (iterator->base + iterator->ngpio <= chip->base) {
+		list_add(&chip->list, &iterator->list);
+		return 0;
 	}
 
-	if (!err)
-		list_add_tail(&chip->list, pos);
+	dev_err(chip->parent,
+	       "GPIO integer space overlap, cannot add chip\n");
+	return -EBUSY;
 
-	return err;
+found:
+	list_add_tail(&chip->list, &iterator->list);
+	return 0;
 }
 
 /**
@@ -252,7 +275,7 @@ static struct gpio_desc *gpio_name_to_desc(const char * const name)
  * Takes the names from gc->names and checks if they are all unique. If they
  * are, they are assigned to their gpio descriptors.
  *
- * Returns -EEXIST if one of the names is already used for a different GPIO.
+ * Warning if one of the names is already used for a different GPIO.
  */
 static int gpiochip_set_desc_names(struct gpio_chip *gc)
 {
@@ -267,7 +290,7 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc)
 
 		gpio = gpio_name_to_desc(gc->names[i]);
 		if (gpio)
-			dev_warn(gc->dev, "Detected name collision for "
+			dev_warn(gc->parent, "Detected name collision for "
 				 "GPIO name '%s'\n",
 				 gc->names[i]);
 	}
@@ -280,7 +303,7 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc)
 }
 
 /**
- * gpiochip_add() - register a gpio_chip
+ * gpiochip_add_data() - register a gpio_chip
  * @chip: the chip to register, with chip->base initialized
  * Context: potentially before irqs will work
  *
@@ -288,15 +311,15 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc)
  * because the chip->base is invalid or already associated with a
  * different chip.  Otherwise it returns zero as a success code.
  *
- * When gpiochip_add() is called very early during boot, so that GPIOs
- * can be freely used, the chip->dev device must be registered before
+ * When gpiochip_add_data() is called very early during boot, so that GPIOs
+ * can be freely used, the chip->parent device must be registered before
  * the gpio framework's arch_initcall().  Otherwise sysfs initialization
  * for GPIOs will fail rudely.
  *
  * If chip->base is negative, this requests dynamic assignment of
  * a range of valid GPIOs.
  */
-int gpiochip_add(struct gpio_chip *chip)
+int gpiochip_add_data(struct gpio_chip *chip, void *data)
 {
 	unsigned long	flags;
 	int		status = 0;
@@ -308,6 +331,13 @@ int gpiochip_add(struct gpio_chip *chip)
 	if (!descs)
 		return -ENOMEM;
 
+	chip->data = data;
+
+	if (chip->ngpio == 0) {
+		chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
+		return -EINVAL;
+	}
+
 	spin_lock_irqsave(&gpio_lock, flags);
 
 	if (base < 0) {
@@ -348,8 +378,8 @@ int gpiochip_add(struct gpio_chip *chip)
 	INIT_LIST_HEAD(&chip->pin_ranges);
 #endif
 
-	if (!chip->owner && chip->dev && chip->dev->driver)
-		chip->owner = chip->dev->driver->owner;
+	if (!chip->owner && chip->parent && chip->parent->driver)
+		chip->owner = chip->parent->driver->owner;
 
 	status = gpiochip_set_desc_names(chip);
 	if (status)
@@ -389,7 +419,7 @@ err_free_descs:
 		chip->label ? : "generic");
 	return status;
 }
-EXPORT_SYMBOL_GPL(gpiochip_add);
+EXPORT_SYMBOL_GPL(gpiochip_add_data);
 
 /**
  * gpiochip_remove() - unregister a gpio_chip
@@ -424,7 +454,8 @@ void gpiochip_remove(struct gpio_chip *chip)
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
 	if (requested)
-		dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
+		dev_crit(chip->parent,
+			 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
 
 	kfree(chip->desc);
 	chip->desc = NULL;
@@ -659,7 +690,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
  * gpiochip, providing an irq domain to translate the local IRQs to
  * global irqs in the gpiolib core, and making sure that the gpiochip
  * is passed as chip data to all related functions. Driver callbacks
- * need to use container_of() to get their local state containers back
+ * need to use gpiochip_get_data() to get their local state containers back
  * from the gpiochip passed as chip data. An irqdomain will be stored
  * in the gpiochip that shall be used by the driver to handle IRQ number
  * translation. The gpiochip will need to be initialized and registered
@@ -683,15 +714,16 @@ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 	if (!gpiochip || !irqchip)
 		return -EINVAL;
 
-	if (!gpiochip->dev) {
+	if (!gpiochip->parent) {
 		pr_err("missing gpiochip .dev parent pointer\n");
 		return -EINVAL;
 	}
-	of_node = gpiochip->dev->of_node;
+	of_node = gpiochip->parent->of_node;
 #ifdef CONFIG_OF_GPIO
 	/*
 	 * If the gpiochip has an assigned OF node this takes precedence
-	 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
+	 * FIXME: get rid of this and use gpiochip->parent->of_node
+	 * everywhere
 	 */
 	if (gpiochip->of_node)
 		of_node = gpiochip->of_node;
@@ -1279,13 +1311,7 @@ static int _gpiod_get_raw_value(const struct gpio_desc *desc)
 	chip = desc->chip;
 	offset = gpio_chip_hwgpio(desc);
 	value = chip->get ? chip->get(chip, offset) : -EIO;
-	/*
-	 * FIXME: fix all drivers to clamp to [0,1] or return negative,
-	 * then change this to:
-	 * value = value < 0 ? value : !!value;
-	 * so we can properly propagate error codes.
-	 */
-	value = !!value;
+	value = value < 0 ? value : !!value;
 	trace_gpio_value(desc_to_gpio(desc), 1, value);
 	return value;
 }
@@ -2512,7 +2538,7 @@ static int gpiolib_seq_show(struct seq_file *s, void *v)
 
 	seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
 			chip->base, chip->base + chip->ngpio - 1);
-	dev = chip->dev;
+	dev = chip->parent;
 	if (dev)
 		seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
 			dev_name(dev));