PIO: Uncouple pin groups from pin functions

am: 4cdad48d03

Change-Id: I44417329cc71f7ffc09811508e9d4412652a9bc9

6 files changed, 146 insertions, 144 deletions

diff --git a/drivers/pinctrl/android-things/devices.c b/drivers/pinctrl/android-things/devices.c
index 6ba8905ce1c8..1ec2c34edb84 100644
--- a/drivers/pinctrl/android-things/devices.c
+++ b/drivers/pinctrl/android-things/devices.c
@@ -275,7 +275,7 @@ static int register_device_and_aux(struct bcm_device *dev)
 /* Restore the device's default pin configuration and register it. */
 static inline int register_default_device(struct bcm_device *dev)
 {
-	int ret = set_device_config(dev, NULL);
+	int ret = set_device_default_config(dev);
 
 	if (ret)
 		return ret;
@@ -410,10 +410,9 @@ int platform_devices_init(struct class *class)
 			unregister_device_and_aux(dev, bdev);
 		}
 
-		if ((ret = expand_property(bdev, PROP_PULL, 0)))
+		if ((ret = expand_property(bdev, PROP_PULL, false)))
 			goto err_init_prop;
-		if ((ret = expand_property(bdev, PROP_FUNC,
-					   bdev->pin_groups[0].function)))
+		if ((ret = expand_property(bdev, PROP_FUNC, true)))
 			goto err_init_prop;
 
 		/*
@@ -426,7 +425,7 @@ int platform_devices_init(struct class *class)
 		 * to be registered if we mess up.
 		 */
 		if (bdev->init_unreg) {
-			if ((ret = set_device_config(bdev, NULL)))
+			if ((ret = set_device_default_config(bdev)))
 				goto err_init_prop;
 		}
 	}
@@ -659,28 +658,25 @@ static inline int set_function_gpio(struct pin_device *dev)
 
 /* Replace a pin used by a device and register a pin device for the old pin. */
 static inline int replace_pin(struct bcm_device *bcm_dev,
-			      struct pin_group *group, u32 pin)
+			      struct pin_function *pin)
 {
 	struct pin_device *pin_dev;
 	int ret;
 	__be32 *pin_prop;
 	__be32 *function;
-	u32 pin_index;
 	u32 old_pin;
 
-	pin_index = pin - group->base;
 	pin_prop = find_pin_property(bcm_dev->node.of_node, PROP_PINS,
-				     pin_index);
-
+				     pin->index);
 	if (!pin_prop) {
 		pr_err(TAG "unable to find pin index %d in %s\n",
-		       pin_index, bcm_dev->name);
+		       pin->index, bcm_dev->name);
 		return -EINVAL;
 	}
 
 	old_pin = be32_to_cpup(pin_prop);
 
-	*pin_prop = cpu_to_be32p(&pin);
+	*pin_prop = cpu_to_be32p(&pin->pin);
 
 	if (!(pin_dev = get_pin_device_by_pin(old_pin))) {
 		/*
@@ -693,14 +689,14 @@ static inline int replace_pin(struct bcm_device *bcm_dev,
 
 	/* Set the pin's function property in the device tree. */
 	function = find_pin_property(bcm_dev->node.of_node, PROP_FUNC,
-				     pin_index);
+				     pin->index);
 	if (!function) {
 		pr_err(TAG "unable to find pin function index %d in %s\n",
-		       pin_index, bcm_dev->name);
+		       pin->index, bcm_dev->name);
 		return -EINVAL;
 	}
 
-	*function = cpu_to_be32p(&group->function);
+	*function = cpu_to_be32p(&pin->function);
 
 	return 0;
 }
@@ -713,7 +709,7 @@ static inline int replace_pin(struct bcm_device *bcm_dev,
  */
 static inline int __set_function(struct pin_device *dev,
 				 struct bcm_device *bcm_dev,
-				 struct pin_group *group)
+				 struct pin_function *pin)
 {
 	struct device *new_dev;
 	struct device *exdev;
@@ -723,7 +719,7 @@ static inline int __set_function(struct pin_device *dev,
 	int has_pin;
 	int ret = 0;
 
-	if (!bcm_dev->node.path)
+	if (!pin)
 		return set_function_gpio(dev);
 
 	if (!bcm_dev->node.of_node) {
@@ -743,19 +739,8 @@ static inline int __set_function(struct pin_device *dev,
 	/* Unregister this device so we can change its pins. */
 	unregister_device_and_maybe_aux(new_dev, bcm_dev);
 
-	if (bcm_dev->use_default) {
-		/*
-		 * By default, this device uses non-user pins. Rather than mix
-		 * user and non-user pins, set this device to use all user pins
-		 * as soon as it is requested.
-		 */
-		if ((ret = set_device_config(bcm_dev, group))) {
-			pr_err(TAG "unable to set config for %s\n",
-			       bcm_dev->name);
-			return ret;
-		}
-	} else if (!has_pin) {
-		if ((ret = replace_pin(bcm_dev, group, dev->pin)))
+	if (!has_pin) {
+		if ((ret = replace_pin(bcm_dev, pin)))
 			return ret;
 	}
 
@@ -810,31 +795,30 @@ static inline int __set_function(struct pin_device *dev,
 }
 
 int set_function(struct pin_device *dev, struct bcm_device *bcm_dev,
-		 struct pin_group *group)
+		 struct pin_function *pin)
 {
 	int ret;
 
 	mutex_lock(&sysfs_mutex);
-	ret = __set_function(dev, bcm_dev, group);
+	ret = __set_function(dev, bcm_dev, pin);
 	mutex_unlock(&sysfs_mutex);
 
 	return ret;
 }
 
-
 /*
- * Find a matching pin group and return this pin's index in the property
+ * Find a matching pin_function and return this pin's index in the property
  * list.
  */
-static inline u32 get_pin_property_index(struct bcm_device *dev, u32 pin)
+static inline int get_pin_property_index(struct bcm_device *dev, u32 pin)
 {
-	struct pin_group *groups;
-	size_t i;
+	int i, j;
 
-	groups = dev->pin_groups;
-	for (i = 0 ; dev->pin_group_count; i++) {
-		if (pin_in_group(pin, groups[i].base, dev->pin_count))
-			return pin - groups[i].base;
+	for (i = 0; i < dev->pin_count; i++) {
+		for (j = 0; j < dev->pin_groups; j++) {
+			if (dev->pins[i][j].pin == pin)
+				return i;
+		}
 	}
 
 	return -1;
diff --git a/drivers/pinctrl/android-things/devicetree.c b/drivers/pinctrl/android-things/devicetree.c
index f33f31662bf7..3c327c85d400 100644
--- a/drivers/pinctrl/android-things/devicetree.c
+++ b/drivers/pinctrl/android-things/devicetree.c
@@ -120,11 +120,14 @@ static inline void fill_value(__be32 *array, u32 value, int length)
  *
  * @dev:	The device to check.
  * @prop_name:	The string name of the property to check.
- * @value:	The new value to fill an expanded property with.
+ * @require:	Whether or not to require an existing property with prop_name
+ *		and at least length 1. This is for the function property which
+ *		does not have a default value to use. In that case, duplicate
+ *		the one existing value for each pin in the node.
  *
  * Returns 0 on success.
  */
-int expand_property(struct bcm_device *dev, const char *prop_name, u32 value)
+int expand_property(struct bcm_device *dev, const char *prop_name, bool require)
 {
 	struct of_changeset changeset;
 	struct device_node *prop;
@@ -135,6 +138,7 @@ int expand_property(struct bcm_device *dev, const char *prop_name, u32 value)
 	int ret;
 	unsigned long action;
 	int i = 0;
+	u32 value;
 
 	of_changeset_init(&changeset);
 
@@ -164,6 +168,18 @@ int expand_property(struct bcm_device *dev, const char *prop_name, u32 value)
 			 */
 			of_node_put(prop);
 			continue;
+		} else if (require && (!pull || pull_length < 1)) {
+			/*
+			 * We require a property of at least length 1 in order
+			 * to fill the rest of the entries.
+			 */
+			pr_err(TAG "%s[%d] doesn't have the required property %s\n",
+			       dev->name, i - 1, prop_name);
+			goto err_prop;
+		} else if (require) {
+			value = be32_to_cpup(pull->value);
+		} else {
+			value = 0;
 		}
 
 		new_pull = create_property(prop_name, pins_length);
@@ -225,27 +241,23 @@ struct device *find_device_by_node(struct device_node *node)
 }
 
 /*
- * set_device_config() - Sets a device's device tree configuration.
+ * set_device_default_config() - Sets a device's device tree configuration to
+ * the default specified in platform_devices.
  *
  * @dev:	The device to change.
- * @group:	The new pin group to set, or NULL for the default.
  *
  * Returns 0 on success.
  */
-int set_device_config(struct bcm_device *dev, struct pin_group *group)
+int set_device_default_config(struct bcm_device *dev)
 {
 	struct device_node *prop;
 	struct property *pins, *function, *pull;
 	__be32 *list;
 	__be32 *flist = NULL;
 	__be32 *plist = NULL;
-	u32 pin;
 	int length;
 	int i, j, total;
 
-	if (!group)
-		group = &dev->pin_groups[0];
-
 	i = 0;
 	j = 0;
 	while ((prop = of_parse_phandle(dev->node.of_node, STATE_0, i++))) {
@@ -273,15 +285,9 @@ int set_device_config(struct bcm_device *dev, struct pin_group *group)
 		length /= sizeof(*list);
 		total = j + length;
 
-		if (total > dev->pin_count) {
-			pr_warn(TAG "%s has %d pins, more than the %d we know about\n",
-				dev->name, total, dev->pin_count);
-		}
-
 		for ( ; j < total && j < dev->pin_count; j++) {
-			pin = group->base + j;
-			*list++ = cpu_to_be32p(&pin);
-			*flist++ = cpu_to_be32p(&group->function);
+			*list++ = cpu_to_be32p(&dev->pins[j]->pin);
+			*flist++ = cpu_to_be32p(&dev->pins[j]->function);
 			*plist++ = cpu_to_be32p(&dev->pin_pull[j]);
 		}
 
diff --git a/drivers/pinctrl/android-things/platform_devices.c b/drivers/pinctrl/android-things/platform_devices.c
index cfa04258709e..fbc9d8592e4c 100644
--- a/drivers/pinctrl/android-things/platform_devices.c
+++ b/drivers/pinctrl/android-things/platform_devices.c
@@ -40,14 +40,21 @@ struct bcm_device platform_devices[] = {
 		.aux_dev = { .path = NULL },
 		.use_default = 0,
 		.always_unreg_aux = 0,
-		.init_unreg = 0,
+		.init_unreg = 1,
 		.pin_count = 5,
 		.pin_pull = (u32 []) { NONE, NONE, NONE, NONE, NONE },
-		.pin_group_count = 1,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 7,
-				.function = ALT0
+		.pin_groups = 1,
+		.pins = (struct pin_function *[]) {
+			(struct pin_function []) {
+				{ .pin = 7, .index = 0, .function = GPIO_OUT }
+			}, (struct pin_function []) {
+				{ .pin = 8, .index = 1, .function = GPIO_OUT }
+			}, (struct pin_function []) {
+				{ .pin = 9, .index = 2, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 10, .index = 3, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 11, .index = 4, .function = ALT0 }
 			}
 		},
 		.excl = NULL
@@ -60,14 +67,14 @@ struct bcm_device platform_devices[] = {
 		.init_unreg = 1,
 		.pin_count = 2,
 		.pin_pull = (u32 []) { NONE, NONE, },
-		.pin_group_count = 2,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 12,
-				.function = ALT0
-			}, {
-				.base = 18,
-				.function = ALT5
+		.pin_groups = 2,
+		.pins = (struct pin_function *[]) {
+			(struct pin_function []) {
+				{ .pin = 18, .index = 0, .function = ALT5 },
+				{ .pin = 12, .index = 0, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 13, .index = 1, .function = ALT0 },
+				{ .pin = 19, .index = 1, .function = ALT5 }
 			}
 		},
 		.excl = (struct bcm_device *[]) {
@@ -83,11 +90,12 @@ struct bcm_device platform_devices[] = {
 		.init_unreg = 1,
 		.pin_count = 2,
 		.pin_pull = (u32 []) { NONE, NONE },
-		.pin_group_count = 1,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 2,
-				.function = ALT0
+		.pin_groups = 1,
+		.pins = (struct pin_function *[]) {
+			(struct pin_function []) {
+				{ .pin = 2, .index = 0, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 3, .index = 1, .function = ALT0 }
 			}
 		},
 		.excl = NULL
@@ -100,14 +108,14 @@ struct bcm_device platform_devices[] = {
 		.init_unreg = 0,
 		.pin_count = 2,
 		.pin_pull = (u32 []) { NONE, UP },
-		.pin_group_count = 2,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 32,
-				.function = ALT3
-			}, {
-				.base = 14,
-				.function = ALT0
+		.pin_groups = 2,
+		.pins = (struct pin_function *[]) {
+			(struct pin_function []) {
+				{ .pin = 32, .index = 0, .function = ALT3 },
+				{ .pin = 14, .index = 0, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 33, .index = 1, .function = ALT3 },
+				{ .pin = 15, .index = 1, .function = ALT0 }
 			}
 		},
 		.excl = NULL
@@ -120,11 +128,12 @@ struct bcm_device platform_devices[] = {
 		.init_unreg = 0,
 		.pin_count = 2,
 		.pin_pull = (u32 []) { NONE, UP },
-		.pin_group_count = 1,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 14,
-				.function = ALT5
+		.pin_groups = 1,
+		.pins = (struct pin_function *[]) {
+			(struct pin_function []) {
+				{ .pin = 14, .index = 0, .function = ALT5 }
+			}, (struct pin_function []) {
+				{ .pin = 15, .index = 1, .function = ALT5 }
 			}
 		},
 		.excl = NULL
@@ -137,11 +146,16 @@ struct bcm_device platform_devices[] = {
 		.init_unreg = 1,
 		.pin_count = 4,
 		.pin_pull = (u32 []) { NONE, NONE, NONE, NONE },
-		.pin_group_count = 1,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 18,
-				.function = ALT0
+		.pin_groups = 1,
+		.pins = (struct pin_function *[]) {
+			(struct pin_function []) {
+				{ .pin = 18, .index = 0, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 19, .index = 1, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 20, .index = 2, .function = ALT0 }
+			}, (struct pin_function []) {
+				{ .pin = 21, .index = 3, .function = ALT0 }
 			}
 		},
 		.excl = (struct bcm_device *[]) {
@@ -155,14 +169,9 @@ struct bcm_device platform_devices[] = {
 		.use_default = 0,
 		.always_unreg_aux = 0,
 		.init_unreg = 0,
-		.pin_count = 26,
-		.pin_group_count = 1,
-		.pin_groups = (struct pin_group []) {
-			{
-				.base = 2,
-				.function = GPIO
-			}
-		},
+		.pin_count = 0,
+		.pin_groups = 0,
+		.pins = NULL,
 		.excl = NULL
 	}, {
 		.name = NULL
diff --git a/drivers/pinctrl/android-things/platform_devices.h b/drivers/pinctrl/android-things/platform_devices.h
index a8e6340de2f1..f698662ff8c5 100644
--- a/drivers/pinctrl/android-things/platform_devices.h
+++ b/drivers/pinctrl/android-things/platform_devices.h
@@ -36,7 +36,8 @@ struct node_path {
 
 /* Broadcom pin function numbers. See drivers/pinctrl/bcm/pinctrl-bcm2835.c */
 enum bcm_fsel {
-	GPIO = 0,
+	GPIO_IN = 0,
+	GPIO_OUT = 1,
 	ALT0 = 4,
 	ALT1 = 5,
 	ALT2 = 6,
@@ -46,13 +47,17 @@ enum bcm_fsel {
 };
 
 /*
- * struct pin_group - Defines the starting pin and hardware-specific function
- * number for a group of pins used by a peripheral. We assume that each group
- * has the same function number and contains bcm_device.pin_count consecutive
- * pins.
+ * struct pin_function - Defines the pin number and hardware-specific function
+ * number for a pin used by a device. We assume that devices may have different
+ * groups of pins that they can use and that mixing between groups is allowed,
+ * but no one pin can take on multiple functions for one device. We also assume
+ * that each group of pins for a device follows the same order of functions,
+ * and that this order is followed by pinctrl properties in the device tree.
+ * The index member here is used to specify the pin's place in its group.
  */
-struct pin_group {
-	u32 base;
+struct pin_function {
+	u32 pin;
+	int index;
 	enum bcm_fsel function;
 };
 
@@ -65,12 +70,12 @@ struct pin_group {
  * @aux_dev:	A node_path containing the device tree node for this device's
  *		auxiliary device. The auxiliary device may depend on this
  *		device, or this device may depend on it.
- * @use_default:	Whether or not we should register this device on
- *			a default pin_group if nobody is using it. For example,
- *			uart0 on the Raspberry Pi 3 is also used for Bluetooth,
- *			so we need to register uart0 again when the user stops
- *			using it directly. pin_groups[0] is the default
- *			pin_group.
+ * @use_default:	Whether or not we should register this device on a set
+ *			of default pin_functions if nobody is using it. For
+ *			example, uart0 on the Raspberry Pi 3 is also used For
+ *			Bluetooth, so we need to register uart0 again when the
+ *			user stops using it directly. bcm_device.pins[n][0] are
+ *			the default pin_functions used.
  * @always_unreg_aux:	Whether or not we should unregister the auxiliary device
  *			whenever we unregister this device. This flag also
  *			controls the order in which the devices get
@@ -79,11 +84,14 @@ struct pin_group {
  *		module. This is useful for mutually exclusive devices which all
  *		may be registered at boot.
  * @pin_count:	The number of pins used by this peripheral.
+ * @pin_groups:	The number of pin groups that can be used by this device.
  * @pin_pull:	Specifies default resistor values for this device. Only used
  *		with use_default.
- * @pin_group_count:	The number of pin_groups available to this device and
- *			the length of the following array.
- * @pin_groups:	Array of pin_groups for this device.
+ * @pins:	An array of arrays of pin_functions available to this device.
+ *		The top-level array has bcm_device.pin_count entries, and each
+ *		array in it has bcm_device.pin_groups entries. The first
+ *		pin_functions in each array make up the default group for each
+ *		device.
  * @excl:	NULL-terminated array of bcm_devices that are mutually exclusive
  *		with this device. Whenever we register this device, we must
  *		first unregister every device in this array. For example, i2s
@@ -98,9 +106,9 @@ struct bcm_device {
 	int always_unreg_aux:1;
 	int init_unreg:1;
 	int pin_count;
+	int pin_groups;
 	u32 *pin_pull;
-	int pin_group_count;
-	struct pin_group *pin_groups;
+	struct pin_function **pins;
 	struct bcm_device **excl;
 };
 
diff --git a/drivers/pinctrl/android-things/runtimepinconfig.h b/drivers/pinctrl/android-things/runtimepinconfig.h
index 3e61e87c9f86..8cdec46d2522 100644
--- a/drivers/pinctrl/android-things/runtimepinconfig.h
+++ b/drivers/pinctrl/android-things/runtimepinconfig.h
@@ -25,7 +25,7 @@
 
 #define TAG "runtimepinconfig: "
 
-struct pin_group;
+struct pin_function;
 struct bcm_device;
 
 /*
@@ -56,7 +56,7 @@ ssize_t resistor_store(struct device *dev, struct device_attribute *attr,
 		       const char *buf, size_t buflen);
 
 int set_function(struct pin_device *dev, struct bcm_device *bcm_dev,
-		 struct pin_group *group);
+		 struct pin_function *pin);
 int set_resistor(struct pin_device *dev, u32 resistor);
 
 struct pin_device *track_pin_device(struct platform_device *dev);
@@ -67,13 +67,9 @@ int pin_devices_init(void);
 
 int get_pin(struct device_node *node, u32 *pin);
 int device_has_pin(struct device_node *node, u32 pin);
-int expand_property(struct bcm_device *dev, const char *prop_name, u32 value);
+int expand_property(struct bcm_device *dev, const char *prop_name,
+		    bool require);
 struct device *find_device_by_node(struct device_node *node);
-int set_device_config(struct bcm_device *dev, struct pin_group *group);
-
-static inline int pin_in_group(int pin, int base, int count)
-{
-	return (pin >= base && pin < base + count);
-}
+int set_device_default_config(struct bcm_device *dev);
 
 #endif /* RUNTIMEPINCONFIG_H_ */
diff --git a/drivers/pinctrl/android-things/sysfs.c b/drivers/pinctrl/android-things/sysfs.c
index eb264489d243..8602a47bea0e 100644
--- a/drivers/pinctrl/android-things/sysfs.c
+++ b/drivers/pinctrl/android-things/sysfs.c
@@ -23,16 +23,14 @@
 
 /*
  * These functions are the sysfs interface. Parse the user input and match it to
- * a peripheral device or resistor value. Use the pin number to determine the
- * pin_group, if necessary.
+ * a pin on a peripheral device or a resistor value.
  */
 ssize_t function_store(struct device *dev, struct device_attribute *attr,
 		       const char *buf, size_t bufsize)
 {
 	struct pin_device *pin_dev = dev_get_drvdata(dev);
 	struct bcm_device *bcm_dev = NULL;
-	size_t i, namelen, inlen;
-	struct pin_group *group;
+	size_t i, j, namelen, inlen;
 	int ret;
 
 	for (inlen = 0; buf[inlen] != '\n' && inlen < bufsize; inlen++)
@@ -54,18 +52,19 @@ ssize_t function_store(struct device *dev, struct device_attribute *attr,
 		pr_warn(TAG "no matching platform device found on pin %d\n",
 			pin_dev->pin);
 		return -ENODEV;
+	} else if (bcm_dev->pin_count == 0) {
+		ret = set_function(pin_dev, bcm_dev, NULL);
+		return (ret) ? ret : bufsize;
 	}
 
-	group = bcm_dev->pin_groups;
-
-	/* Match the pin number to a pin group available to the device. */
-	for (i = 0; i < bcm_dev->pin_group_count; i++) {
-		if (pin_in_group(pin_dev->pin, group[i].base,
-				 bcm_dev->pin_count)) {
-			if ((ret = set_function(pin_dev, bcm_dev, &group[i])))
-				pr_err(TAG "set function %s failed on pin %d\n",
-				       bcm_dev->name, pin_dev->pin);
-			return (ret) ? ret : bufsize;
+	/* Loop over the possible pins for this device. */
+	for (i = 0; i < bcm_dev->pin_count; i++) {
+		for (j = 0; j < bcm_dev->pin_groups; j++) {
+			if (bcm_dev->pins[i][j].pin == pin_dev->pin) {
+				ret = set_function(pin_dev, bcm_dev,
+						   &bcm_dev->pins[i][j]);
+				return (ret) ? ret : bufsize;
+			}
 		}
 	}