dm: serial: Add driver model support for ns16550

Add driver model support so that ns16550 can support operation both with
and without driver model.

The driver needs a clock frequency so cannot stand alone unfortunately. The
clock frequency must be provided by a separate driver.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/include/ns16550.h b/include/ns16550.h
index d93e28e..5784cfd 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -23,6 +23,14 @@
 
 #include <linux/types.h>
 
+#ifdef CONFIG_DM_SERIAL
+/*
+ * For driver model we always use one byte per register, and sort out the
+ * differences in the driver
+ */
+#define CONFIG_SYS_NS16550_REG_SIZE (-1)
+#endif
+
 #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
 #error "Please define NS16550 registers size."
 #elif defined(CONFIG_SYS_NS16550_MEM32)
@@ -37,6 +45,21 @@
 	unsigned char postpad_##x[-CONFIG_SYS_NS16550_REG_SIZE - 1];
 #endif
 
+/**
+ * struct ns16550_platdata - information about a NS16550 port
+ *
+ * @base:		Base register address
+ * @reg_shift:		Shift size of registers (0=byte, 1=16bit, 2=32bit...)
+ * @clock:		UART base clock speed in Hz
+ */
+struct ns16550_platdata {
+	unsigned char *base;
+	int reg_shift;
+	int clock;
+};
+
+struct udevice;
+
 struct NS16550 {
 	UART_REG(rbr);		/* 0 */
 	UART_REG(ier);		/* 1 */
@@ -65,6 +88,9 @@ struct NS16550 {
 	UART_REG(scr);		/* 10*/
 	UART_REG(ssr);		/* 11*/
 #endif
+#ifdef CONFIG_DM_SERIAL
+	struct ns16550_platdata *plat;
+#endif
 };
 
 #define thr rbr
@@ -183,3 +209,30 @@ void NS16550_reinit(NS16550_t com_port, int baud_divisor);
  * @return baud rate divisor that should be used
  */
 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate);
+
+/**
+ * ns16550_serial_ofdata_to_platdata() - convert DT to platform data
+ *
+ * Decode a device tree node for an ns16550 device. This includes the
+ * register base address and register shift properties. The caller must set
+ * up the clock frequency.
+ *
+ * @dev:	dev to decode platform data for
+ * @return:	0 if OK, -EINVAL on error
+ */
+int ns16550_serial_ofdata_to_platdata(struct udevice *dev);
+
+/**
+ * ns16550_serial_probe() - probe a serial port
+ *
+ * This sets up the serial port ready for use, except for the baud rate
+ * @return 0, or -ve on error
+ */
+int ns16550_serial_probe(struct udevice *dev);
+
+/**
+ * struct ns16550_serial_ops - ns16550 serial operations
+ *
+ * These should be used by the client driver for the driver's 'ops' member
+ */
+extern const struct dm_serial_ops ns16550_serial_ops;