console: Add simplified 'serdev' framework from Linux kernel

Port 'serdev' UART-slave deivce framework found in recent Linux
kernels (post 4.13) in order to be able to port 'serdev' slave drivers
from Linux.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 63 insertions, 0 deletions

diff --git a/include/console.h b/include/console.h
index da867e70a6..673921331d 100644
--- a/include/console.h
+++ b/include/console.h
@@ -23,6 +23,7 @@
 #include <param.h>
 #include <linux/list.h>
 #include <driver.h>
+#include <serdev.h>
 #include <clock.h>
 #include <kfifo.h>
 
@@ -66,8 +67,34 @@ struct console_device {
 
 	struct cdev devfs;
 	struct cdev_operations fops;
+
+	struct serdev_device serdev;
 };
 
+static inline struct serdev_device *to_serdev_device(struct device_d *d)
+{
+	struct console_device *cdev =
+		container_of(d, struct console_device, class_dev);
+	return &cdev->serdev;
+}
+
+static inline struct console_device *
+to_console_device(struct serdev_device *serdev)
+{
+	return container_of(serdev, struct console_device, serdev);
+}
+
+static inline struct device_node *
+console_is_serdev_node(struct console_device *cdev)
+{
+	struct device_d *dev = cdev->dev;
+	if (dev && dev->device_node &&
+	    of_get_child_count(dev->device_node))
+		return dev->device_node;
+
+	return NULL;
+}
+
 int console_register(struct console_device *cdev);
 int console_unregister(struct console_device *cdev);
 
diff --git a/include/serdev.h b/include/serdev.h
new file mode 100644
index 0000000000..efc735fedf
--- /dev/null
+++ b/include/serdev.h
@@ -0,0 +1,36 @@
+#ifndef _SERDEV_H_
+#define _SERDEV_H_
+
+#include <driver.h>
+#include <poller.h>
+#include <kfifo.h>
+
+/**
+ * struct serdev_device - Basic representation of an serdev device
+ *
+ * @dev:		Corresponding device
+ * @fifo:		Circular buffer used for console draining
+ * @buf:		Buffer used to pass Rx data to consumers
+ * @poller		Async poller used to poll this serdev
+ * @polling_interval:	Async poller periodicity
+ * @polling_window:	Duration of a single busy loop poll
+ * @receive_buf:	Function called with data received from device;
+ *			returns number of bytes accepted;
+ */
+struct serdev_device {
+	struct device_d *dev;
+	struct kfifo *fifo;
+	unsigned char *buf;
+	struct poller_async poller;
+	uint64_t polling_interval;
+	uint64_t polling_window;
+
+	int (*receive_buf)(struct serdev_device *, const unsigned char *,
+			   size_t);
+};
+
+int serdev_device_open(struct serdev_device *);
+unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
+int serdev_device_write(struct serdev_device *, const unsigned char *,
+			size_t, unsigned long);
+#endif