[U-Boot] [PATCH v2 4/8] x86: slimbootloader: Add serial driver

[Park, Aiden]

- Get serial port information from the serial port info hob
- Leverage ns16550 driver with slimbootloader specific platform data

Signed-off-by: Aiden Park <aiden.park at intel.com>
---
 arch/x86/cpu/slimbootloader/Makefile          |  2 +-
 arch/x86/cpu/slimbootloader/serial.c          | 62 +++++++++++++++++++
 .../asm/arch-slimbootloader/slimbootloader.h  | 33 ++++++++++
 3 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86/cpu/slimbootloader/serial.c

diff --git a/arch/x86/cpu/slimbootloader/Makefile b/arch/x86/cpu/slimbootloader/Makefile
index 4b0b3e71c9..3e62f564cd 100644
--- a/arch/x86/cpu/slimbootloader/Makefile
+++ b/arch/x86/cpu/slimbootloader/Makefile
@@ -2,4 +2,4 @@
 #
 # Copyright (C) 2019 Intel Corporation <www.intel.com>
 
-obj-y += car.o slimbootloader.o hob.o dram.o
+obj-y += car.o slimbootloader.o hob.o dram.o serial.o
diff --git a/arch/x86/cpu/slimbootloader/serial.c b/arch/x86/cpu/slimbootloader/serial.c
new file mode 100644
index 0000000000..186c7a79ef
--- /dev/null
+++ b/arch/x86/cpu/slimbootloader/serial.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Intel Corporation <www.intel.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <ns16550.h>
+#include <serial.h>
+#include <asm/arch/slimbootloader.h>
+
+int slimbootloader_serial_ofdata_to_platdata(struct udevice *dev)
+{
+	const struct efi_guid guid = LOADER_SERIAL_PORT_INFO_GUID;
+	struct serial_port_info *serial_info = NULL;
+	struct ns16550_platdata *plat = dev->platdata;
+
+	serial_info = (struct serial_port_info *)
+	    get_next_guid_hob_data(&guid, gd->arch.hob_list);
+
+	if (!serial_info) {
+		debug("failed to get serial port information\n");
+		return -ENOENT;
+	}
+	debug("type:%d base=0x%08x baudrate=%d stride=%d clk=%d\n",
+	      serial_info->type,
+	      serial_info->base,
+	      serial_info->baud,
+	      serial_info->stride,
+	      serial_info->clk);
+
+	/*
+	 * The serial_info->type provides port io or mmio access type info,
+	 * but the access type will be controlled by
+	 * CONFIG_SYS_NS16550_PORT_MAPPED or CONFIG_SYS_NS16550_MEM32.
+	 *
+	 * TBD: ns16550 access type configuration in runtime.
+	 *      ex) plat->access_type = serial_info->type
+	 */
+	plat->base = serial_info->base;
+	/* ns16550 uses reg_shift, then covert stride to shift */
+	plat->reg_shift = (serial_info->stride >> 1);
+	plat->clock = serial_info->clk;
+
+	return 0;
+}
+
+static const struct udevice_id slimbootloader_serial_ids[] = {
+	{ .compatible = "intel,slimbootloader-uart" },
+	{}
+};
+
+U_BOOT_DRIVER(serial_slimbootloader) = {
+	.name	= "serial_slimbootloader",
+	.id	= UCLASS_SERIAL,
+	.of_match = slimbootloader_serial_ids,
+	.ofdata_to_platdata = slimbootloader_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,
+};
diff --git a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
index c85201e711..b05e527148 100644
--- a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
+++ b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
@@ -16,6 +16,12 @@
 	{ 0xa9, 0xe4, 0x92, 0xf3, 0x57, 0xd1, 0x28, 0x32 } \
 	}
 
+#define LOADER_SERIAL_PORT_INFO_GUID \
+	{ \
+	0x6c6872fe, 0x56a9, 0x4403, \
+	{ 0xbb, 0x98, 0x95, 0x8d, 0x62, 0xde, 0x87, 0xf1 } \
+	}
+
 /**
  * A single entry of memory map information
  *
@@ -48,6 +54,33 @@ struct memory_map_info {
 	struct memory_map_entry entry[0];
 } __packed;
 
+/**
+ * This includes serial port info which has already been initialized in previous
+ * Slim Bootloader stage.
+ * The Slim Bootloader initializes serial port regardless of debug/release build
+ * modes, and it passes the information to a payload thru hob. So, a payload can
+ * re-use the serial information without re-initializing serial port.
+ *
+ * @rev   : revision of serial_port_info structure. currently 1.
+ * @rsvd  : padding for alignment
+ * @type  : port io: 1, mmio: 2
+ * @base  : io base address. ex) 0x3f8, 0x80001000
+ * @baud  : uart baud rate
+ * @stride: register stride in Bytes
+ * @clk   : uart frequency in Hz
+ * @rsvd1 : reserved
+ */
+struct serial_port_info {
+	u8      rev;
+	u8      rsvd[3];
+	u32     type;
+	u32     base;
+	u32     baud;
+	u32     stride;
+	u32     clk;
+	u32     rsvd1;
+} __packed;
+
 /**
  * This returns a pointer to hob data buffer if the given guid hob is found.
  *
-- 
2.20.1