1 files changed, 99 insertions, 16 deletions

diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
index 6ff59c89d867..22749ab0428a 100644
--- a/drivers/tty/serial/serial_base_bus.c
+++ b/drivers/tty/serial/serial_base_bus.c
@@ -8,9 +8,12 @@
  * The serial core bus manages the serial core controller instances.
  */
 
+#include <linux/cleanup.h>
 #include <linux/container_of.h>
 #include <linux/device.h>
+#include <linux/idr.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/serial_core.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -19,14 +22,28 @@
 
 static bool serial_base_initialized;
 
-static int serial_base_match(struct device *dev, struct device_driver *drv)
+static const struct device_type serial_ctrl_type = {
+	.name = "ctrl",
+};
+
+static const struct device_type serial_port_type = {
+	.name = "port",
+};
+
+static int serial_base_match(struct device *dev, const struct device_driver *drv)
 {
-	int len = strlen(drv->name);
+	if (dev->type == &serial_ctrl_type &&
+	    str_has_prefix(drv->name, serial_ctrl_type.name))
+		return 1;
+
+	if (dev->type == &serial_port_type &&
+	    str_has_prefix(drv->name, serial_port_type.name))
+		return 1;
 
-	return !strncmp(dev_name(dev), drv->name, len);
+	return 0;
 }
 
-static struct bus_type serial_base_bus_type = {
+static const struct bus_type serial_base_bus_type = {
 	.name = "serial-base",
 	.match = serial_base_match,
 };
@@ -48,30 +65,36 @@ static int serial_base_device_init(struct uart_port *port,
 				   struct device *parent_dev,
 				   const struct device_type *type,
 				   void (*release)(struct device *dev),
-				   int id)
+				   unsigned int ctrl_id,
+				   unsigned int port_id)
 {
 	device_initialize(dev);
 	dev->type = type;
 	dev->parent = parent_dev;
 	dev->bus = &serial_base_bus_type;
 	dev->release = release;
+	device_set_of_node_from_dev(dev, parent_dev);
 
 	if (!serial_base_initialized) {
 		dev_dbg(port->dev, "uart_add_one_port() called before arch_initcall()?\n");
 		return -EPROBE_DEFER;
 	}
 
-	return dev_set_name(dev, "%s.%s.%d", type->name, dev_name(port->dev), id);
-}
+	if (type == &serial_ctrl_type)
+		return dev_set_name(dev, "%s:%d", dev_name(port->dev), ctrl_id);
 
-static const struct device_type serial_ctrl_type = {
-	.name = "ctrl",
-};
+	if (type == &serial_port_type)
+		return dev_set_name(dev, "%s:%d.%d", dev_name(port->dev),
+				    ctrl_id, port_id);
+
+	return -EINVAL;
+}
 
 static void serial_base_ctrl_release(struct device *dev)
 {
 	struct serial_ctrl_device *ctrl_dev = to_serial_base_ctrl_device(dev);
 
+	of_node_put(dev->of_node);
 	kfree(ctrl_dev);
 }
 
@@ -81,6 +104,7 @@ void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev)
 		return;
 
 	device_del(&ctrl_dev->dev);
+	put_device(&ctrl_dev->dev);
 }
 
 struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
@@ -93,10 +117,12 @@ struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
 	if (!ctrl_dev)
 		return ERR_PTR(-ENOMEM);
 
+	ida_init(&ctrl_dev->port_ida);
+
 	err = serial_base_device_init(port, &ctrl_dev->dev,
 				      parent, &serial_ctrl_type,
 				      serial_base_ctrl_release,
-				      port->ctrl_id);
+				      port->ctrl_id, 0);
 	if (err)
 		goto err_put_device;
 
@@ -112,14 +138,11 @@ err_put_device:
 	return ERR_PTR(err);
 }
 
-static const struct device_type serial_port_type = {
-	.name = "port",
-};
-
 static void serial_base_port_release(struct device *dev)
 {
 	struct serial_port_device *port_dev = to_serial_base_port_device(dev);
 
+	of_node_put(dev->of_node);
 	kfree(port_dev);
 }
 
@@ -127,16 +150,31 @@ struct serial_port_device *serial_base_port_add(struct uart_port *port,
 						struct serial_ctrl_device *ctrl_dev)
 {
 	struct serial_port_device *port_dev;
+	int min = 0, max = -1;	/* Use -1 for max to apply IDA defaults */
 	int err;
 
 	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 	if (!port_dev)
 		return ERR_PTR(-ENOMEM);
 
+	/* Device driver specified port_id vs automatic assignment? */
+	if (port->port_id) {
+		min = port->port_id;
+		max = port->port_id;
+	}
+
+	err = ida_alloc_range(&ctrl_dev->port_ida, min, max, GFP_KERNEL);
+	if (err < 0) {
+		kfree(port_dev);
+		return ERR_PTR(err);
+	}
+
+	port->port_id = err;
+
 	err = serial_base_device_init(port, &port_dev->dev,
 				      &ctrl_dev->dev, &serial_port_type,
 				      serial_base_port_release,
-				      port->line);
+				      port->ctrl_id, port->port_id);
 	if (err)
 		goto err_put_device;
 
@@ -150,18 +188,63 @@ struct serial_port_device *serial_base_port_add(struct uart_port *port,
 
 err_put_device:
 	put_device(&port_dev->dev);
+	ida_free(&ctrl_dev->port_ida, port->port_id);
 
 	return ERR_PTR(err);
 }
 
 void serial_base_port_device_remove(struct serial_port_device *port_dev)
 {
+	struct serial_ctrl_device *ctrl_dev;
+	struct device *parent;
+
 	if (!port_dev)
 		return;
 
+	parent = port_dev->dev.parent;
+	ctrl_dev = to_serial_base_ctrl_device(parent);
+
 	device_del(&port_dev->dev);
+	ida_free(&ctrl_dev->port_ida, port_dev->port->port_id);
+	put_device(&port_dev->dev);
+}
+
+#ifdef CONFIG_SERIAL_CORE_CONSOLE
+
+/**
+ * serial_base_match_and_update_preferred_console - Match and update a preferred console
+ * @drv: Serial port device driver
+ * @port: Serial port instance
+ *
+ * Tries to match and update the preferred console for a serial port for
+ * the kernel command line option console=DEVNAME:0.0.
+ *
+ * Cannot be called early for ISA ports, depends on struct device.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int serial_base_match_and_update_preferred_console(struct uart_driver *drv,
+						   struct uart_port *port)
+{
+	const char *port_match __free(kfree) = NULL;
+	int ret;
+
+	port_match = kasprintf(GFP_KERNEL, "%s:%d.%d", dev_name(port->dev),
+			       port->ctrl_id, port->port_id);
+	if (!port_match)
+		return -ENOMEM;
+
+	ret = match_devname_and_update_preferred_console(port_match,
+							 drv->dev_name,
+							 port->line);
+	if (ret == -ENOENT)
+		return 0;
+
+	return ret;
 }
 
+#endif
+
 static int serial_base_init(void)
 {
 	int ret;