rockchip: Add serial support

Add support for the Rockchip serial device using the ns16550 driver.
This uses driver model and device tree for both SPL and U-Boot proper.

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

drivers/serial/Kconfig

@@ -109,6 +109,15 @@ config DEBUG_UART_SHIFT
 	  value. Use this value to specify the shift to use, where 0=byte
 	  registers, 2=32-bit word registers, etc.
 
+config ROCKCHIP_SERIAL
+	bool "Rockchip on-chip UART support"
+	depends on ARCH_UNIPHIER && DM_SERIAL
+	help
+	  Select this to enable a debug UART for Rockchip devices. This uses
+	  the ns16550 driver. You will need to #define CONFIG_SYS_NS16550 in
+	  your board config header. The clock input is automatically set to
+	  use the oscillator (24MHz).
+
 config SANDBOX_SERIAL
 	bool "Sandbox UART support"
 	depends on SANDBOX && DM

drivers/serial/Makefile

@@ -40,6 +40,7 @@ obj-$(CONFIG_ZYNQ_SERIAL) += serial_zynq.o
 obj-$(CONFIG_BFIN_SERIAL) += serial_bfin.o
 obj-$(CONFIG_FSL_LPUART) += serial_lpuart.o
 obj-$(CONFIG_MXS_AUART) += mxs_auart.o
+obj-$(CONFIG_ROCKCHIP_SERIAL) += serial_rockchip.o
 obj-$(CONFIG_ARC_SERIAL) += serial_arc.o
 obj-$(CONFIG_TEGRA_SERIAL) += serial_tegra.o
 obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o

drivers/serial/serial_rockchip.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <ns16550.h>
+#include <serial.h>
+#include <asm/arch/clock.h>
+
+static const struct udevice_id rockchip_serial_ids[] = {
+	{ .compatible = "rockchip,rk3288-uart" },
+	{ }
+};
+
+static int rockchip_serial_ofdata_to_platdata(struct udevice *dev)
+{
+	struct ns16550_platdata *plat = dev_get_platdata(dev);
+	int ret;
+
+	ret = ns16550_serial_ofdata_to_platdata(dev);
+	if (ret)
+		return ret;
+
+	/* Do all Rockchip parts use 24MHz? */
+	plat->clock = 24 * 1000000;
+
+	return 0;
+}
+
+U_BOOT_DRIVER(serial_ns16550) = {
+	.name	= "serial_rockchip",
+	.id	= UCLASS_SERIAL,
+	.of_match = rockchip_serial_ids,
+	.ofdata_to_platdata = rockchip_serial_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
+	.priv_auto_alloc_size = sizeof(struct NS16550),
+	.probe = ns16550_serial_probe,
+	.ops	= &ns16550_serial_ops,
+	.flags	= DM_FLAG_PRE_RELOC,
+};