of: Rename of_modalias_node()

This helper does not produce a real modalias, but tries to get the
"product" compatible part of the "vendor,product" compatibles only. It
is far from creating a purely useful modalias string and does not seem
to be used like that directly anyway, so let's try to give this helper a
more meaningful name before moving there a real modalias helper (already
existing under of/device.c).

Also update the various documentations to refer to the strings as
"aliases" rather than "modaliases" which has a real meaning in the Linux
kernel.

There is no functional change.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Wolfram Sang <wsa@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Link: https://lore.kernel.org/r/20230404172148.82422-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/acpi/bus.c

@@ -817,9 +817,10 @@ static bool acpi_of_modalias(struct acpi_device *adev,
  * @modalias:   Pointer to buffer that modalias value will be copied into
  * @len:	Length of modalias buffer
  *
- * This is a counterpart of of_modalias_node() for struct acpi_device objects.
- * If there is a compatible string for @adev, it will be copied to @modalias
- * with the vendor prefix stripped; otherwise, @default_id will be used.
+ * This is a counterpart of of_alias_from_compatible() for struct acpi_device
+ * objects. If there is a compatible string for @adev, it will be copied to
+ * @modalias with the vendor prefix stripped; otherwise, @default_id will be
+ * used.
  */
 void acpi_set_modalias(struct acpi_device *adev, const char *default_id,
 		       char *modalias, size_t len)

drivers/gpu/drm/drm_mipi_dsi.c

@@ -160,7 +160,7 @@ of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
 	int ret;
 	u32 reg;
 
-	if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
+	if (of_alias_from_compatible(node, info.type, sizeof(info.type)) < 0) {
 		drm_err(host, "modalias failure on %pOF\n", node);
 		return ERR_PTR(-EINVAL);
 	}

drivers/hsi/hsi_core.c

@@ -207,7 +207,7 @@ static void hsi_add_client_from_dt(struct hsi_port *port,
 	if (!cl)
 		return;
 
-	err = of_modalias_node(client, name, sizeof(name));
+	err = of_alias_from_compatible(client, name, sizeof(name));
 	if (err)
 		goto err;
 

drivers/i2c/busses/i2c-powermac.c

@@ -284,7 +284,7 @@ static bool i2c_powermac_get_type(struct i2c_adapter *adap,
 	 */
 
 	/* First try proper modalias */
-	if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
+	if (of_alias_from_compatible(node, tmp, sizeof(tmp)) >= 0) {
 		snprintf(type, type_size, "MAC,%s", tmp);
 		return true;
 	}

drivers/i2c/i2c-core-of.c

@@ -27,7 +27,7 @@ int of_i2c_get_board_info(struct device *dev, struct device_node *node,
 
 	memset(info, 0, sizeof(*info));
 
-	if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) {
+	if (of_alias_from_compatible(node, info->type, sizeof(info->type)) < 0) {
 		dev_err(dev, "of_i2c: modalias failure on %pOF\n", node);
 		return -EINVAL;
 	}

drivers/of/base.c

@@ -1208,19 +1208,23 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from,
 EXPORT_SYMBOL(of_find_matching_node_and_match);
 
 /**
- * of_modalias_node - Lookup appropriate modalias for a device node
+ * of_alias_from_compatible - Lookup appropriate alias for a device node
+ *			      depending on compatible
  * @node:	pointer to a device tree node
- * @modalias:	Pointer to buffer that modalias value will be copied into
- * @len:	Length of modalias value
+ * @alias:	Pointer to buffer that alias value will be copied into
+ * @len:	Length of alias value
  *
  * Based on the value of the compatible property, this routine will attempt
- * to choose an appropriate modalias value for a particular device tree node.
+ * to choose an appropriate alias value for a particular device tree node.
  * It does this by stripping the manufacturer prefix (as delimited by a ',')
  * from the first entry in the compatible list property.
  *
+ * Note: The matching on just the "product" side of the compatible is a relic
+ * from I2C and SPI. Please do not add any new user.
+ *
  * Return: This routine returns 0 on success, <0 on failure.
  */
-int of_modalias_node(struct device_node *node, char *modalias, int len)
+int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
 {
 	const char *compatible, *p;
 	int cplen;
@@ -1229,10 +1233,10 @@ int of_modalias_node(struct device_node *node, char *modalias, int len)
 	if (!compatible || strlen(compatible) > cplen)
 		return -ENODEV;
 	p = strchr(compatible, ',');
-	strscpy(modalias, p ? p + 1 : compatible, len);
+	strscpy(alias, p ? p + 1 : compatible, len);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(of_modalias_node);
+EXPORT_SYMBOL_GPL(of_alias_from_compatible);
 
 /**
  * of_find_node_by_phandle - Find a node given a phandle

drivers/spi/spi.c

@@ -2354,8 +2354,8 @@ of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
 	}
 
 	/* Select device driver */
-	rc = of_modalias_node(nc, spi->modalias,
-				sizeof(spi->modalias));
+	rc = of_alias_from_compatible(nc, spi->modalias,
+				      sizeof(spi->modalias));
 	if (rc < 0) {
 		dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
 		goto err_out;

include/linux/of.h

@@ -373,7 +373,8 @@ extern int of_n_addr_cells(struct device_node *np);
 extern int of_n_size_cells(struct device_node *np);
 extern const struct of_device_id *of_match_node(
 	const struct of_device_id *matches, const struct device_node *node);
-extern int of_modalias_node(struct device_node *node, char *modalias, int len);
+extern int of_alias_from_compatible(const struct device_node *node, char *alias,
+				    int len);
 extern void of_print_phandle_args(const char *msg, const struct of_phandle_args *args);
 extern int __of_parse_phandle_with_args(const struct device_node *np,
 	const char *list_name, const char *cells_name, int cell_count,