Merge tag 'gpio-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO fixes from Linus Walleij:
 "A bunch of GPIO fixes for the v4.7 series:

   - Drop the lock before reading out the GPIO direction setting in
     drivers supporting the .get_direction() callback: some of them may
     be slowpath.

   - Flush GPIO direction setting before locking a GPIO as an IRQ: some
     electronics or other poking around in the registers behind our back
     may have happened, so flush the direction status before trying to
     lock the line for use by IRQs.

   - Bail out silently when asked to perform operations on NULL GPIO
     descriptors.  That is what all the get_*_optional() is about: we
     get optional GPIO handles, if they are not there, we get NULL.

   - Handle compatible ioctl() correctly: we need to convert the ioctl()
     pointer using compat_ptr() here like everyone else.

   - Disable the broken .to_irq() on the LPC32xx platform.  The whole
     irqchip infrastructure was replaced in the last merge window, and a
     new implementation will be needed"

* tag 'gpio-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: drop lock before reading GPIO direction
  gpio: bail out silently on NULL descriptors
  gpio: handle compatible ioctl() pointers
  gpio: flush direction status in gpiochip_lock_as_irq()
  gpio: lpc32xx: disable broken to_irq support

1 files changed, 40 insertions, 11 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d407f904a31c..24f60d28f0c0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -20,6 +20,7 @@
 #include <linux/cdev.h>
 #include <linux/fs.h>
 #include <linux/uaccess.h>
+#include <linux/compat.h>
 #include <uapi/linux/gpio.h>
 
 #include "gpiolib.h"
@@ -316,7 +317,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct gpio_device *gdev = filp->private_data;
 	struct gpio_chip *chip = gdev->chip;
-	int __user *ip = (int __user *)arg;
+	void __user *ip = (void __user *)arg;
 
 	/* We fail any subsequent ioctl():s when the chip is gone */
 	if (!chip)
@@ -388,6 +389,14 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	return -EINVAL;
 }
 
+#ifdef CONFIG_COMPAT
+static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
+			      unsigned long arg)
+{
+	return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
 /**
  * gpio_chrdev_open() - open the chardev for ioctl operations
  * @inode: inode for this chardev
@@ -431,7 +440,9 @@ static const struct file_operations gpio_fileops = {
 	.owner = THIS_MODULE,
 	.llseek = noop_llseek,
 	.unlocked_ioctl = gpio_ioctl,
-	.compat_ioctl = gpio_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = gpio_ioctl_compat,
+#endif
 };
 
 static void gpiodevice_release(struct device *dev)
@@ -618,6 +629,8 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
 		goto err_free_label;
 	}
 
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
 	for (i = 0; i < chip->ngpio; i++) {
 		struct gpio_desc *desc = &gdev->descs[i];
 
@@ -649,8 +662,6 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
 		}
 	}
 
-	spin_unlock_irqrestore(&gpio_lock, flags);
-
 #ifdef CONFIG_PINCTRL
 	INIT_LIST_HEAD(&gdev->pin_ranges);
 #endif
@@ -1356,10 +1367,13 @@ done:
 /*
  * This descriptor validation needs to be inserted verbatim into each
  * function taking a descriptor, so we need to use a preprocessor
- * macro to avoid endless duplication.
+ * macro to avoid endless duplication. If the desc is NULL it is an
+ * optional GPIO and calls should just bail out.
  */
 #define VALIDATE_DESC(desc) do { \
-	if (!desc || !desc->gdev) { \
+	if (!desc) \
+		return 0; \
+	if (!desc->gdev) { \
 		pr_warn("%s: invalid GPIO\n", __func__); \
 		return -EINVAL; \
 	} \
@@ -1370,7 +1384,9 @@ done:
 	} } while (0)
 
 #define VALIDATE_DESC_VOID(desc) do { \
-	if (!desc || !desc->gdev) { \
+	if (!desc) \
+		return; \
+	if (!desc->gdev) { \
 		pr_warn("%s: invalid GPIO\n", __func__); \
 		return; \
 	} \
@@ -2066,17 +2082,30 @@ EXPORT_SYMBOL_GPL(gpiod_to_irq);
  */
 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
 {
-	if (offset >= chip->ngpio)
-		return -EINVAL;
+	struct gpio_desc *desc;
+
+	desc = gpiochip_get_desc(chip, offset);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	/* Flush direction if something changed behind our back */
+	if (chip->get_direction) {
+		int dir = chip->get_direction(chip, offset);
+
+		if (dir)
+			clear_bit(FLAG_IS_OUT, &desc->flags);
+		else
+			set_bit(FLAG_IS_OUT, &desc->flags);
+	}
 
-	if (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].flags)) {
+	if (test_bit(FLAG_IS_OUT, &desc->flags)) {
 		chip_err(chip,
 			  "%s: tried to flag a GPIO set as output for IRQ\n",
 			  __func__);
 		return -EIO;
 	}
 
-	set_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
+	set_bit(FLAG_USED_AS_IRQ, &desc->flags);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);