1 files changed, 172 insertions, 61 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0dee0e0c247a..d66139dc410d 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -60,6 +60,7 @@ struct gpio_desc {
 #define FLAG_ACTIVE_LOW	6	/* sysfs value has active low */
 #define FLAG_OPEN_DRAIN	7	/* Gpio is open drain type */
 #define FLAG_OPEN_SOURCE 8	/* Gpio is open source type */
+#define FLAG_USED_AS_IRQ 9	/* GPIO is connected to an IRQ */
 
 #define ID_SHIFT	16	/* add new flags before this one */
 
@@ -96,12 +97,47 @@ static int gpiod_get_value(const struct gpio_desc *desc);
 static void gpiod_set_value(struct gpio_desc *desc, int value);
 static int gpiod_cansleep(const struct gpio_desc *desc);
 static int gpiod_to_irq(const struct gpio_desc *desc);
+static int gpiod_lock_as_irq(struct gpio_desc *desc);
+static void gpiod_unlock_as_irq(struct gpio_desc *desc);
 static int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
 static int gpiod_export_link(struct device *dev, const char *name,
 			     struct gpio_desc *desc);
 static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value);
 static void gpiod_unexport(struct gpio_desc *desc);
 
+#ifdef CONFIG_DEBUG_FS
+#define gpiod_emerg(desc, fmt, ...)			                \
+	pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+                 ##__VA_ARGS__)
+#define gpiod_crit(desc, fmt, ...)			                \
+	pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label,  \
+                 ##__VA_ARGS__)
+#define gpiod_err(desc, fmt, ...)				        \
+	pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label,   \
+                 ##__VA_ARGS__)
+#define gpiod_warn(desc, fmt, ...)				        \
+	pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label,  \
+                 ##__VA_ARGS__)
+#define gpiod_info(desc, fmt, ...)				        \
+	pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label,  \
+                ##__VA_ARGS__)
+#define gpiod_dbg(desc, fmt, ...)				   \
+	pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+                 ##__VA_ARGS__)
+#else
+#define gpiod_emerg(desc, fmt, ...)			           \
+	pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_crit(desc, fmt, ...)			           \
+	pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_err(desc, fmt, ...)				   \
+	pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_warn(desc, fmt, ...)				   \
+	pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_info(desc, fmt, ...)				   \
+	pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_dbg(desc, fmt, ...)				   \
+	pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#endif
 
 static inline void desc_set_label(struct gpio_desc *d, const char *label)
 {
@@ -130,6 +166,17 @@ static struct gpio_desc *gpio_to_desc(unsigned gpio)
 }
 
 /**
+ * Convert an offset on a certain chip to a corresponding descriptor
+ */
+static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip,
+						 unsigned int offset)
+{
+	unsigned int gpio = chip->base + offset;
+
+	return gpio_to_desc(gpio);
+}
+
+/**
  * Convert a GPIO descriptor to the integer namespace.
  * This should disappear in the future but is needed since we still
  * use GPIO numbers for error messages and sysfs nodes
@@ -395,6 +442,7 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
 	desc->flags &= ~GPIO_TRIGGER_MASK;
 
 	if (!gpio_flags) {
+		gpiod_unlock_as_irq(desc);
 		ret = 0;
 		goto free_id;
 	}
@@ -433,6 +481,12 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
 	if (ret < 0)
 		goto free_id;
 
+	ret = gpiod_lock_as_irq(desc);
+	if (ret < 0) {
+		gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
+		goto free_id;
+	}
+
 	desc->flags |= gpio_flags;
 	return 0;
 
@@ -1637,8 +1691,9 @@ static int gpiod_direction_input(struct gpio_desc *desc)
 
 	chip = desc->chip;
 	if (!chip->get || !chip->direction_input) {
-		pr_warn("%s: missing get() or direction_input() operations\n",
-			__func__);
+		gpiod_warn(desc,
+			"%s: missing get() or direction_input() operations\n",
+			 __func__);
 		return -EIO;
 	}
 
@@ -1658,8 +1713,7 @@ static int gpiod_direction_input(struct gpio_desc *desc)
 	if (status) {
 		status = chip->request(chip, offset);
 		if (status < 0) {
-			pr_debug("GPIO-%d: chip request fail, %d\n",
-				desc_to_gpio(desc), status);
+			gpiod_dbg(desc, "chip request fail, %d\n", status);
 			/* and it's not available to anyone else ...
 			 * gpio_request() is the fully clean solution.
 			 */
@@ -1677,8 +1731,7 @@ lose:
 fail:
 	spin_unlock_irqrestore(&gpio_lock, flags);
 	if (status)
-		pr_debug("%s: gpio-%d status %d\n", __func__,
-			 desc_to_gpio(desc), status);
+		gpiod_dbg(desc, "%s status %d\n", __func__, status);
 	return status;
 }
 
@@ -1700,6 +1753,14 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
 		return -EINVAL;
 	}
 
+	/* GPIOs used for IRQs shall not be set as output */
+	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
+		gpiod_err(desc,
+			  "%s: tried to set a GPIO tied to an IRQ as output\n",
+			  __func__);
+		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);
@@ -1710,8 +1771,9 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
 
 	chip = desc->chip;
 	if (!chip->set || !chip->direction_output) {
-		pr_warn("%s: missing set() or direction_output() operations\n",
-			__func__);
+		gpiod_warn(desc,
+		       "%s: missing set() or direction_output() operations\n",
+		       __func__);
 		return -EIO;
 	}
 
@@ -1731,8 +1793,7 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
 	if (status) {
 		status = chip->request(chip, offset);
 		if (status < 0) {
-			pr_debug("GPIO-%d: chip request fail, %d\n",
-				desc_to_gpio(desc), status);
+			gpiod_dbg(desc, "chip request fail, %d\n", status);
 			/* and it's not available to anyone else ...
 			 * gpio_request() is the fully clean solution.
 			 */
@@ -1750,8 +1811,7 @@ lose:
 fail:
 	spin_unlock_irqrestore(&gpio_lock, flags);
 	if (status)
-		pr_debug("%s: gpio-%d status %d\n", __func__,
-			 desc_to_gpio(desc), status);
+		gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
 	return status;
 }
 
@@ -1783,8 +1843,9 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
 
 	chip = desc->chip;
 	if (!chip->set || !chip->set_debounce) {
-		pr_debug("%s: missing set() or set_debounce() operations\n",
-			__func__);
+		gpiod_dbg(desc,
+			  "%s: missing set() or set_debounce() operations\n",
+			  __func__);
 		return -ENOTSUPP;
 	}
 
@@ -1806,8 +1867,7 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
 fail:
 	spin_unlock_irqrestore(&gpio_lock, flags);
 	if (status)
-		pr_debug("%s: gpio-%d status %d\n", __func__,
-			 desc_to_gpio(desc), status);
+		gpiod_dbg(desc, "%s: status %d\n", __func__, status);
 
 	return status;
 }
@@ -1840,6 +1900,19 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce);
  * that the GPIO was actually requested.
  */
 
+static int _gpiod_get_value(const struct gpio_desc *desc)
+{
+	struct gpio_chip	*chip;
+	int value;
+	int offset;
+
+	chip = desc->chip;
+	offset = gpio_chip_hwgpio(desc);
+	value = chip->get ? chip->get(chip, offset) : 0;
+	trace_gpio_value(desc_to_gpio(desc), 1, value);
+	return value;
+}
+
 /**
  * __gpio_get_value() - return a gpio's value
  * @gpio: gpio whose value will be returned
@@ -1851,19 +1924,11 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce);
  */
 static int gpiod_get_value(const struct gpio_desc *desc)
 {
-	struct gpio_chip	*chip;
-	int value;
-	int offset;
-
 	if (!desc)
 		return 0;
-	chip = desc->chip;
-	offset = gpio_chip_hwgpio(desc);
 	/* Should be using gpio_get_value_cansleep() */
-	WARN_ON(chip->can_sleep);
-	value = chip->get ? chip->get(chip, offset) : 0;
-	trace_gpio_value(desc_to_gpio(desc), 1, value);
-	return value;
+	WARN_ON(desc->chip->can_sleep);
+	return _gpiod_get_value(desc);
 }
 
 int __gpio_get_value(unsigned gpio)
@@ -1895,8 +1960,9 @@ static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value)
 	}
 	trace_gpio_direction(desc_to_gpio(desc), value, err);
 	if (err < 0)
-		pr_err("%s: Error in set_value for open drain gpio%d err %d\n",
-					__func__, desc_to_gpio(desc), err);
+		gpiod_err(desc,
+			  "%s: Error in set_value for open drain err %d\n",
+			  __func__, err);
 }
 
 /*
@@ -1922,8 +1988,23 @@ static void _gpio_set_open_source_value(struct gpio_desc *desc, int value)
 	}
 	trace_gpio_direction(desc_to_gpio(desc), !value, err);
 	if (err < 0)
-		pr_err("%s: Error in set_value for open source gpio%d err %d\n",
-					__func__, desc_to_gpio(desc), err);
+		gpiod_err(desc,
+			  "%s: Error in set_value for open source err %d\n",
+			  __func__, err);
+}
+
+static void _gpiod_set_value(struct gpio_desc *desc, int value)
+{
+	struct gpio_chip	*chip;
+
+	chip = desc->chip;
+	trace_gpio_value(desc_to_gpio(desc), 0, value);
+	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+		_gpio_set_open_drain_value(desc, value);
+	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+		_gpio_set_open_source_value(desc, value);
+	else
+		chip->set(chip, gpio_chip_hwgpio(desc), value);
 }
 
 /**
@@ -1937,20 +2018,12 @@ static void _gpio_set_open_source_value(struct gpio_desc *desc, int value)
  */
 static void gpiod_set_value(struct gpio_desc *desc, int value)
 {
-	struct gpio_chip	*chip;
 
 	if (!desc)
 		return;
-	chip = desc->chip;
 	/* Should be using gpio_set_value_cansleep() */
-	WARN_ON(chip->can_sleep);
-	trace_gpio_value(desc_to_gpio(desc), 0, value);
-	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
-		_gpio_set_open_drain_value(desc, value);
-	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
-		_gpio_set_open_source_value(desc, value);
-	else
-		chip->set(chip, gpio_chip_hwgpio(desc), value);
+	WARN_ON(desc->chip->can_sleep);
+	_gpiod_set_value(desc, value);
 }
 
 void __gpio_set_value(unsigned gpio, int value)
@@ -2008,6 +2081,58 @@ int __gpio_to_irq(unsigned gpio)
 }
 EXPORT_SYMBOL_GPL(__gpio_to_irq);
 
+/**
+ * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ
+ * @gpio: the GPIO line to lock as used for IRQ
+ *
+ * This is used directly by GPIO drivers that want to lock down
+ * a certain GPIO line to be used as IRQs, for example in the
+ * .to_irq() callback of their gpio_chip, or in the .irq_enable()
+ * of its irq_chip implementation if the GPIO is known from that
+ * code.
+ */
+static int gpiod_lock_as_irq(struct gpio_desc *desc)
+{
+	if (!desc)
+		return -EINVAL;
+
+	if (test_bit(FLAG_IS_OUT, &desc->flags)) {
+		gpiod_err(desc,
+			  "%s: tried to flag a GPIO set as output for IRQ\n",
+			  __func__);
+		return -EIO;
+	}
+
+	set_bit(FLAG_USED_AS_IRQ, &desc->flags);
+	return 0;
+}
+
+int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset));
+}
+EXPORT_SYMBOL_GPL(gpio_lock_as_irq);
+
+/**
+ * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ
+ * @gpio: the GPIO line to unlock from IRQ usage
+ *
+ * This is used directly by GPIO drivers that want to indicate
+ * that a certain GPIO is no longer used exclusively for IRQ.
+ */
+static void gpiod_unlock_as_irq(struct gpio_desc *desc)
+{
+	if (!desc)
+		return;
+
+	clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
+}
+
+void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	return gpiod_unlock_as_irq(gpiochip_offset_to_desc(chip, offset));
+}
+EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
 
 /* There's no value in making it easy to inline GPIO calls that may sleep.
  * Common examples include ones connected to I2C or SPI chips.
@@ -2015,18 +2140,10 @@ EXPORT_SYMBOL_GPL(__gpio_to_irq);
 
 static int gpiod_get_value_cansleep(const struct gpio_desc *desc)
 {
-	struct gpio_chip	*chip;
-	int value;
-	int offset;
-
 	might_sleep_if(extra_checks);
 	if (!desc)
 		return 0;
-	chip = desc->chip;
-	offset = gpio_chip_hwgpio(desc);
-	value = chip->get ? chip->get(chip, offset) : 0;
-	trace_gpio_value(desc_to_gpio(desc), 1, value);
-	return value;
+	return _gpiod_get_value(desc);
 }
 
 int gpio_get_value_cansleep(unsigned gpio)
@@ -2037,19 +2154,10 @@ EXPORT_SYMBOL_GPL(gpio_get_value_cansleep);
 
 static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
 {
-	struct gpio_chip	*chip;
-
 	might_sleep_if(extra_checks);
 	if (!desc)
 		return;
-	chip = desc->chip;
-	trace_gpio_value(desc_to_gpio(desc), 0, value);
-	if (test_bit(FLAG_OPEN_DRAIN,  &desc->flags))
-		_gpio_set_open_drain_value(desc, value);
-	else if (test_bit(FLAG_OPEN_SOURCE,  &desc->flags))
-		_gpio_set_open_source_value(desc, value);
-	else
-		chip->set(chip, gpio_chip_hwgpio(desc), value);
+	_gpiod_set_value(desc, value);
 }
 
 void gpio_set_value_cansleep(unsigned gpio, int value)
@@ -2066,6 +2174,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	unsigned		gpio = chip->base;
 	struct gpio_desc	*gdesc = &chip->desc[0];
 	int			is_out;
+	int			is_irq;
 
 	for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
 		if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
@@ -2073,12 +2182,14 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 
 		gpiod_get_direction(gdesc);
 		is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
-		seq_printf(s, " gpio-%-3d (%-20.20s) %s %s",
+		is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
+		seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
 			gpio, gdesc->label,
 			is_out ? "out" : "in ",
 			chip->get
 				? (chip->get(chip, i) ? "hi" : "lo")
-				: "?  ");
+				: "?  ",
+			is_irq ? "IRQ" : "   ");
 		seq_printf(s, "\n");
 	}
 }