Merge branch 'acpi-modules'

* acpi-modules:
  platform: introduce OF style 'modalias' support for platform bus
  ACPI: fix module autoloading for ACPI enumerated devices
  ACPI: add module autoloading support for ACPI enumerated devices
  ACPI: fix create_modalias() return value handling

7 files changed, 127 insertions, 7 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c0f57ff1502..e00365ccb89 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -86,6 +86,9 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  * Creates hid/cid(s) string needed for modalias and uevent
  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
  * char *modalias: "acpi:IBM0001:ACPI0001"
+ * Return: 0: no _HID and no _CID
+ *         -EINVAL: output error
+ *         -ENOMEM: output is truncated
 */
 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
 			   int size)
@@ -102,8 +105,10 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
 
 	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 		count = snprintf(&modalias[len], size, "%s:", id->id);
-		if (count < 0 || count >= size)
-			return -EINVAL;
+		if (count < 0)
+			return EINVAL;
+		if (count >= size)
+			return -ENOMEM;
 		len += count;
 		size -= count;
 	}
@@ -112,15 +117,71 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
 	return len;
 }
 
+/*
+ * Creates uevent modalias field for ACPI enumerated devices.
+ * Because the other buses does not support ACPI HIDs & CIDs.
+ * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
+ * "acpi:IBM0001:ACPI0001"
+ */
+int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct acpi_device *acpi_dev;
+	int len;
+
+	acpi_dev = ACPI_COMPANION(dev);
+	if (!acpi_dev)
+		return -ENODEV;
+
+	/* Fall back to bus specific way of modalias exporting */
+	if (list_empty(&acpi_dev->pnp.ids))
+		return -ENODEV;
+
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
+				sizeof(env->buf) - env->buflen);
+	if (len <= 0)
+		return len;
+	env->buflen += len;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
+
+/*
+ * Creates modalias sysfs attribute for ACPI enumerated devices.
+ * Because the other buses does not support ACPI HIDs & CIDs.
+ * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
+ * "acpi:IBM0001:ACPI0001"
+ */
+int acpi_device_modalias(struct device *dev, char *buf, int size)
+{
+	struct acpi_device *acpi_dev;
+	int len;
+
+	acpi_dev = ACPI_COMPANION(dev);
+	if (!acpi_dev)
+		return -ENODEV;
+
+	/* Fall back to bus specific way of modalias exporting */
+	if (list_empty(&acpi_dev->pnp.ids))
+		return -ENODEV;
+
+	len = create_modalias(acpi_dev, buf, size -1);
+	if (len <= 0)
+		return len;
+	buf[len++] = '\n';
+	return len;
+}
+EXPORT_SYMBOL_GPL(acpi_device_modalias);
+
 static ssize_t
 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
 	int len;
 
-	/* Device has no HID and no CID or string is >1024 */
 	len = create_modalias(acpi_dev, buf, 1024);
 	if (len <= 0)
-		return 0;
+		return len;
 	buf[len++] = '\n';
 	return len;
 }
@@ -839,8 +900,8 @@ static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 		return -ENOMEM;
 	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
 			      sizeof(env->buf) - env->buflen);
-	if (len >= (sizeof(env->buf) - env->buflen))
-		return -ENOMEM;
+	if (len <= 0)
+		return len;
 	env->buflen += len;
 	return 0;
 }
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 3a94b799f16..bc78848dd59 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -677,7 +677,17 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 			     char *buf)
 {
 	struct platform_device	*pdev = to_platform_device(dev);
-	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
+	int len;
+
+	len = of_device_get_modalias(dev, buf, PAGE_SIZE -1);
+	if (len != -ENODEV)
+		return len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
+	if (len != -ENODEV)
+		return len;
+
+	len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
 
 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 }
@@ -699,6 +709,10 @@ static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
 	if (rc != -ENODEV)
 		return rc;
 
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
+
 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
 			pdev->name);
 	return 0;
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index d74c0b34248..c4c5588ec0f 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -104,6 +104,11 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
 static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
+	int rc;
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
 
 	if (add_uevent_var(env, "MODALIAS=%s%s",
 			   I2C_MODULE_PREFIX, client->name))
@@ -409,6 +414,12 @@ static ssize_t
 show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
+	if (len != -ENODEV)
+		return len;
+
 	return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
 }
 
diff --git a/drivers/of/device.c b/drivers/of/device.c
index f685e55e071..dafb9736ab9 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -85,6 +85,9 @@ ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 	int cplen, i;
 	ssize_t tsize, csize, repend;
 
+	if ((!dev) || (!dev->of_node))
+		return -ENODEV;
+
 	/* Name & Type */
 	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 			 dev->of_node->type);
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 349ebba4b19..827ff49d3d4 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -58,6 +58,11 @@ static ssize_t
 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
 {
 	const struct spi_device	*spi = to_spi_device(dev);
+	int len;
+
+	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+	if (len != -ENODEV)
+		return len;
 
 	return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
 }
@@ -114,6 +119,11 @@ static int spi_match_device(struct device *dev, struct device_driver *drv)
 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	const struct spi_device		*spi = to_spi_device(dev);
+	int rc;
+
+	rc = acpi_device_uevent_modalias(dev, env);
+	if (rc != -ENODEV)
+		return rc;
 
 	add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
 	return 0;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 3e3247d95fd..1151a1dcfe4 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -416,6 +416,9 @@ static inline bool acpi_driver_match_device(struct device *dev,
 	return !!acpi_match_device(drv->acpi_match_table, dev);
 }
 
+int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
+int acpi_device_modalias(struct device *, char *, int);
+
 #define ACPI_PTR(_ptr)	(_ptr)
 
 #else	/* !CONFIG_ACPI */
@@ -495,6 +498,18 @@ static inline bool acpi_driver_match_device(struct device *dev,
 	return false;
 }
 
+static inline int acpi_device_uevent_modalias(struct device *dev,
+				struct kobj_uevent_env *env)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_device_modalias(struct device *dev,
+				char *buf, int size)
+{
+	return -ENODEV;
+}
+
 #define ACPI_PTR(_ptr)	(NULL)
 
 #endif	/* !CONFIG_ACPI */
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index 82ce324fdce..8d7dd6768cb 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -64,6 +64,12 @@ static inline int of_driver_match_device(struct device *dev,
 static inline void of_device_uevent(struct device *dev,
 			struct kobj_uevent_env *env) { }
 
+static inline int of_device_get_modalias(struct device *dev,
+				   char *str, ssize_t len)
+{
+	return -ENODEV;
+}
+
 static inline int of_device_uevent_modalias(struct device *dev,
 				   struct kobj_uevent_env *env)
 {