serdev: Split and export serdev_acpi_get_uart_resource()

The same as for I²C Serial Bus resource split and export
serdev_acpi_get_uart_resource(). We have already a few users
one of which is converted here.

Rationale of this is to consolidate parsing UART Serial Bus
resource in one place as it's done, e.g., for I²C Serial Bus.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210806111736.66591-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 9cdfcfe..6b997aa 100644 (file)
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -564,23 +564,45 @@ struct acpi_serdev_lookup {
        int index;
 };
 
+/**
+ * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
+ * @ares:      ACPI resource
+ * @uart:      Pointer to UARTSerialBus resource will be returned here
+ *
+ * Checks if the given ACPI resource is of type UARTSerialBus.
+ * In this case, returns a pointer to it to the caller.
+ *
+ * Return: True if resource type is of UARTSerialBus, otherwise false.
+ */
+bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
+                                  struct acpi_resource_uart_serialbus **uart)
+{
+       struct acpi_resource_uart_serialbus *sb;
+
+       if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+               return false;
+
+       sb = &ares->data.uart_serial_bus;
+       if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
+               return false;
+
+       *uart = sb;
+       return true;
+}
+EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
+
 static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
 {
        struct acpi_serdev_lookup *lookup = data;
        struct acpi_resource_uart_serialbus *sb;
        acpi_status status;
 
-       if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
-               return 1;
-
-       if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
+       if (!serdev_acpi_get_uart_resource(ares, &sb))
                return 1;
 
        if (lookup->index != -1 && lookup->n++ != lookup->index)
                return 1;
 
-       sb = &ares->data.uart_serial_bus;
-
        status = acpi_get_handle(lookup->device_handle,
                                 sb->resource_source.string_ptr,
                                 &lookup->controller_handle);
@@ -588,7 +610,7 @@ static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
                return 1;
 
        /*
-        * NOTE: Ideally, we would also want to retreive other properties here,
+        * NOTE: Ideally, we would also want to retrieve other properties here,
         * once setting them before opening the device is supported by serdev.
         */
 

diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 9f14f9c..3368c26 100644 (file)
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -327,4 +327,18 @@ static inline int serdev_tty_port_unregister(struct tty_port *port)
 }
 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
 
+struct acpi_resource;
+struct acpi_resource_uart_serialbus;
+
+#ifdef CONFIG_ACPI
+bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
+                                  struct acpi_resource_uart_serialbus **uart);
+#else
+static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
+                                                struct acpi_resource_uart_serialbus **uart)
+{
+       return false;
+}
+#endif /* CONFIG_ACPI */
+
 #endif /*_LINUX_SERDEV_H */