1 files changed, 168 insertions, 95 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b747c76fd2b1..be74bd370f1f 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
@@ -431,14 +440,15 @@ 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)
 {
 	struct gpio_device *gdev = dev_get_drvdata(dev);
 
-	cdev_del(&gdev->chrdev);
 	list_del(&gdev->list);
 	ida_simple_remove(&gpio_ida, gdev->id);
 	kfree(gdev->label);
@@ -471,7 +481,6 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
 
 	/* From this point, the .release() function cleans up gpio_device */
 	gdev->dev.release = gpiodevice_release;
-	get_device(&gdev->dev);
 	pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
 		 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
 		 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
@@ -618,21 +627,38 @@ 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];
 
 		desc->gdev = gdev;
-
-		/* REVISIT: most hardware initializes GPIOs as inputs (often
-		 * with pullups enabled) so power usage is minimized. Linux
-		 * code should set the gpio direction first thing; but until
-		 * it does, and in case chip->get_direction is not set, we may
-		 * expose the wrong direction in sysfs.
+		/*
+		 * REVISIT: most hardware initializes GPIOs as inputs
+		 * (often with pullups enabled) so power usage is
+		 * minimized. Linux code should set the gpio direction
+		 * first thing; but until it does, and in case
+		 * chip->get_direction is not set, we may expose the
+		 * wrong direction in sysfs.
 		 */
-		desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
-	}
 
-	spin_unlock_irqrestore(&gpio_lock, flags);
+		if (chip->get_direction) {
+			/*
+			 * If we have .get_direction, set up the initial
+			 * direction flag from the hardware.
+			 */
+			int dir = chip->get_direction(chip, i);
+
+			if (!dir)
+				set_bit(FLAG_IS_OUT, &desc->flags);
+		} else if (!chip->direction_input) {
+			/*
+			 * If the chip lacks the .direction_input callback
+			 * we logically assume all lines are outputs.
+			 */
+			set_bit(FLAG_IS_OUT, &desc->flags);
+		}
+	}
 
 #ifdef CONFIG_PINCTRL
 	INIT_LIST_HEAD(&gdev->pin_ranges);
@@ -742,6 +768,8 @@ void gpiochip_remove(struct gpio_chip *chip)
 	 * be removed, else it will be dangling until the last user is
 	 * gone.
 	 */
+	cdev_del(&gdev->chrdev);
+	device_del(&gdev->dev);
 	put_device(&gdev->dev);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
@@ -841,7 +869,7 @@ struct gpio_chip *gpiochip_find(void *data,
 
 	spin_lock_irqsave(&gpio_lock, flags);
 	list_for_each_entry(gdev, &gpio_devices, list)
-		if (match(gdev->chip, data))
+		if (gdev->chip && match(gdev->chip, data))
 			break;
 
 	/* No match? */
@@ -1324,14 +1352,6 @@ static int __gpiod_request(struct gpio_desc *desc, const char *label)
 		spin_lock_irqsave(&gpio_lock, flags);
 	}
 done:
-	if (status < 0) {
-		/* Clear flags that might have been set by the caller before
-		 * requesting the GPIO.
-		 */
-		clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
-		clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
-		clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
-	}
 	spin_unlock_irqrestore(&gpio_lock, flags);
 	return status;
 }
@@ -1339,11 +1359,18 @@ 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) { \
-		pr_warn("%s: invalid GPIO\n", __func__); \
+	if (!desc) \
+		return 0; \
+	if (IS_ERR(desc)) {						\
+		pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
+		return PTR_ERR(desc); \
+	} \
+	if (!desc->gdev) { \
+		pr_warn("%s: invalid GPIO (no device)\n", __func__); \
 		return -EINVAL; \
 	} \
 	if ( !desc->gdev->chip ) { \
@@ -1353,8 +1380,14 @@ done:
 	} } while (0)
 
 #define VALIDATE_DESC_VOID(desc) do { \
-	if (!desc || !desc->gdev) { \
-		pr_warn("%s: invalid GPIO\n", __func__); \
+	if (!desc) \
+		return; \
+	if (IS_ERR(desc)) {						\
+		pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
+		return; \
+	} \
+	if (!desc->gdev) { \
+		pr_warn("%s: invalid GPIO (no device)\n", __func__); \
 		return; \
 	} \
 	if (!desc->gdev->chip) { \
@@ -1547,8 +1580,8 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input);
 
 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
 {
-	struct gpio_chip	*chip;
-	int			status = -EINVAL;
+	struct gpio_chip *gc = desc->gdev->chip;
+	int ret;
 
 	/* GPIOs used for IRQs shall not be set as output */
 	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
@@ -1558,28 +1591,50 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
 		return -EIO;
 	}
 
-	/* Open drain pin should not be driven to 1 */
-	if (value && test_bit(FLAG_OPEN_DRAIN,  &desc->flags))
-		return gpiod_direction_input(desc);
-
-	/* Open source pin should not be driven to 0 */
-	if (!value && test_bit(FLAG_OPEN_SOURCE,  &desc->flags))
-		return gpiod_direction_input(desc);
+	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
+		/* First see if we can enable open drain in hardware */
+		if (gc->set_single_ended) {
+			ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
+						   LINE_MODE_OPEN_DRAIN);
+			if (!ret)
+				goto set_output_value;
+		}
+		/* Emulate open drain by not actively driving the line high */
+		if (value)
+			return gpiod_direction_input(desc);
+	}
+	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
+		if (gc->set_single_ended) {
+			ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
+						   LINE_MODE_OPEN_SOURCE);
+			if (!ret)
+				goto set_output_value;
+		}
+		/* Emulate open source by not actively driving the line low */
+		if (!value)
+			return gpiod_direction_input(desc);
+	} else {
+		/* Make sure to disable open drain/source hardware, if any */
+		if (gc->set_single_ended)
+			gc->set_single_ended(gc,
+					     gpio_chip_hwgpio(desc),
+					     LINE_MODE_PUSH_PULL);
+	}
 
-	chip = desc->gdev->chip;
-	if (!chip->set || !chip->direction_output) {
+set_output_value:
+	if (!gc->set || !gc->direction_output) {
 		gpiod_warn(desc,
 		       "%s: missing set() or direction_output() operations\n",
 		       __func__);
 		return -EIO;
 	}
 
-	status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
-	if (status == 0)
+	ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
+	if (!ret)
 		set_bit(FLAG_IS_OUT, &desc->flags);
 	trace_gpio_value(desc_to_gpio(desc), 0, value);
-	trace_gpio_direction(desc_to_gpio(desc), 0, status);
-	return status;
+	trace_gpio_direction(desc_to_gpio(desc), 0, ret);
+	return ret;
 }
 
 /**
@@ -1841,10 +1896,10 @@ static void gpio_chip_set_multiple(struct gpio_chip *chip,
 	}
 }
 
-static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
-				       unsigned int array_size,
-				       struct gpio_desc **desc_array,
-				       int *value_array)
+void gpiod_set_array_value_complex(bool raw, bool can_sleep,
+				   unsigned int array_size,
+				   struct gpio_desc **desc_array,
+				   int *value_array)
 {
 	int i = 0;
 
@@ -1950,8 +2005,8 @@ void gpiod_set_raw_array_value(unsigned int array_size,
 {
 	if (!desc_array)
 		return;
-	gpiod_set_array_value_priv(true, false, array_size, desc_array,
-				   value_array);
+	gpiod_set_array_value_complex(true, false, array_size, desc_array,
+				      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
 
@@ -1972,8 +2027,8 @@ void gpiod_set_array_value(unsigned int array_size,
 {
 	if (!desc_array)
 		return;
-	gpiod_set_array_value_priv(false, false, array_size, desc_array,
-				   value_array);
+	gpiod_set_array_value_complex(false, false, array_size, desc_array,
+				      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
 
@@ -1998,13 +2053,29 @@ EXPORT_SYMBOL_GPL(gpiod_cansleep);
  */
 int gpiod_to_irq(const struct gpio_desc *desc)
 {
-	struct gpio_chip	*chip;
-	int			offset;
+	struct gpio_chip *chip;
+	int offset;
+
+	/*
+	 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
+	 * requires this function to not return zero on an invalid descriptor
+	 * but rather a negative error number.
+	 */
+	if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
+		return -EINVAL;
 
-	VALIDATE_DESC(desc);
 	chip = desc->gdev->chip;
 	offset = gpio_chip_hwgpio(desc);
-	return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
+	if (chip->to_irq) {
+		int retirq = chip->to_irq(chip, offset);
+
+		/* Zero means NO_IRQ */
+		if (!retirq)
+			return -ENXIO;
+
+		return retirq;
+	}
+	return -ENXIO;
 }
 EXPORT_SYMBOL_GPL(gpiod_to_irq);
 
@@ -2018,17 +2089,30 @@ 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 (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].flags)) {
+		if (dir)
+			clear_bit(FLAG_IS_OUT, &desc->flags);
+		else
+			set_bit(FLAG_IS_OUT, &desc->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);
@@ -2176,8 +2260,8 @@ void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
 	might_sleep_if(extra_checks);
 	if (!desc_array)
 		return;
-	gpiod_set_array_value_priv(true, true, array_size, desc_array,
-				   value_array);
+	gpiod_set_array_value_complex(true, true, array_size, desc_array,
+				      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
 
@@ -2199,8 +2283,8 @@ void gpiod_set_array_value_cansleep(unsigned int array_size,
 	might_sleep_if(extra_checks);
 	if (!desc_array)
 		return;
-	gpiod_set_array_value_priv(false, true, array_size, desc_array,
-				   value_array);
+	gpiod_set_array_value_complex(false, true, array_size, desc_array,
+				      value_array);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
 
@@ -2495,28 +2579,13 @@ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(gpiod_get_optional);
 
-/**
- * gpiod_parse_flags - helper function to parse GPIO lookup flags
- * @desc:	gpio to be setup
- * @lflags:	gpio_lookup_flags - returned from of_find_gpio() or
- *		of_get_gpio_hog()
- *
- * Set the GPIO descriptor flags based on the given GPIO lookup flags.
- */
-static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
-{
-	if (lflags & GPIO_ACTIVE_LOW)
-		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
-	if (lflags & GPIO_OPEN_DRAIN)
-		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
-	if (lflags & GPIO_OPEN_SOURCE)
-		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
-}
 
 /**
  * gpiod_configure_flags - helper function to configure a given GPIO
  * @desc:	gpio whose value will be assigned
  * @con_id:	function within the GPIO consumer
+ * @lflags:	gpio_lookup_flags - returned from of_find_gpio() or
+ *		of_get_gpio_hog()
  * @dflags:	gpiod_flags - optional GPIO initialization flags
  *
  * Return 0 on success, -ENOENT if no GPIO has been assigned to the
@@ -2524,10 +2593,17 @@ static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
  * occurred while trying to acquire the GPIO.
  */
 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
-				 enum gpiod_flags dflags)
+		unsigned long lflags, enum gpiod_flags dflags)
 {
 	int status;
 
+	if (lflags & GPIO_ACTIVE_LOW)
+		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+	if (lflags & GPIO_OPEN_DRAIN)
+		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
+	if (lflags & GPIO_OPEN_SOURCE)
+		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+
 	/* No particular flag request, return here... */
 	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
 		pr_debug("no flags found for %s\n", con_id);
@@ -2594,13 +2670,11 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 		return desc;
 	}
 
-	gpiod_parse_flags(desc, lookupflags);
-
 	status = gpiod_request(desc, con_id);
 	if (status < 0)
 		return ERR_PTR(status);
 
-	status = gpiod_configure_flags(desc, con_id, flags);
+	status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
 	if (status < 0) {
 		dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
 		gpiod_put(desc);
@@ -2656,6 +2730,10 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 	if (IS_ERR(desc))
 		return desc;
 
+	ret = gpiod_request(desc, NULL);
+	if (ret)
+		return ERR_PTR(ret);
+
 	if (active_low)
 		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
 
@@ -2666,10 +2744,6 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 			set_bit(FLAG_OPEN_SOURCE, &desc->flags);
 	}
 
-	ret = gpiod_request(desc, NULL);
-	if (ret)
-		return ERR_PTR(ret);
-
 	return desc;
 }
 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
@@ -2722,19 +2796,18 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
 	chip = gpiod_to_chip(desc);
 	hwnum = gpio_chip_hwgpio(desc);
 
-	gpiod_parse_flags(desc, lflags);
-
 	local_desc = gpiochip_request_own_desc(chip, hwnum, name);
 	if (IS_ERR(local_desc)) {
-		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
-		       name, chip->label, hwnum);
-		return PTR_ERR(local_desc);
+		status = PTR_ERR(local_desc);
+		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
+		       name, chip->label, hwnum, status);
+		return status;
 	}
 
-	status = gpiod_configure_flags(desc, name, dflags);
+	status = gpiod_configure_flags(desc, name, lflags, dflags);
 	if (status < 0) {
-		pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
-		       name, chip->label, hwnum);
+		pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
+		       name, chip->label, hwnum, status);
 		gpiochip_free_own_desc(desc);
 		return status;
 	}