serial: ns16550: support using pre-loader serial

- pass pre-loader serial configure by rk atags;
- it depends on serial aliases to find uart port;
- enabled by CONFIG_ROCKCHIP_USING_PRELOADER_SERIAL;

Change-Id: I6723cccc5e1f3dac77203b4cc19cdac631f5133b
Signed-off-by: Joseph Chen <chenjh@rock-chips.com>

arch/arm/lib/crt0.S

@@ -84,6 +84,7 @@ ENTRY(_main)
 	/* set up gd here, outside any C code */
 	mov	r9, r0
 	bl	board_init_f_init_reserve
+	bl	board_init_f_init_serial
 
 	mov	r0, #0
 	bl	board_init_f

arch/arm/lib/crt0_64.S

@@ -83,6 +83,7 @@ ENTRY(_main)
 	/* set up gd here, outside any C code */
 	mov	x18, x0
 	bl	board_init_f_init_reserve
+	bl	board_init_f_init_serial
 
 	mov	x0, #0
 	bl	board_init_f

arch/arm/mach-rockchip/Kconfig

@@ -519,6 +519,13 @@ config ROCKCHIP_PRELOADER_ATAGS
 	  tos, U-Boot, etc. It delivers boot and configure information, shared with pre-loaders
 	  and finally ends with U-Boot.
 
+config ROCKCHIP_PRELOADER_SERIAL
+	bool "Rockchip pre-loader serial"
+	default y if ROCKCHIP_PRELOADER_ATAGS
+	help
+	  This enable U-Boot using pre-loader atags serial configure to initialize console.
+	  It denpends on serial aliases to find pre-loader serial number.
+
 config GICV2
 	bool "ARM GICv2"
 

arch/arm/mach-rockchip/board.c

@@ -16,6 +16,7 @@
 #include <asm/arch/clock.h>
 #include <asm/arch/periph.h>
 #include <asm/arch/boot_mode.h>
+#include <asm/arch/rk_atags.h>
 #ifdef CONFIG_DM_CHARGE_DISPLAY
 #include <power/charge_display.h>
 #endif
@@ -274,6 +275,27 @@ void enable_caches(void)
 	dcache_enable();
 }
 
+#ifdef CONFIG_ROCKCHIP_PRELOADER_SERIAL
+int board_init_f_init_serial(void)
+{
+	struct tag *t = atags_get_tag(ATAG_SERIAL);
+
+	if (t) {
+		gd->serial.using_pre_serial = t->u.serial.enable;
+		gd->serial.addr = t->u.serial.addr;
+		gd->serial.baudrate = t->u.serial.baudrate;
+		gd->serial.id = t->u.serial.id;
+
+		debug("%s: enable=%d, addr=0x%lx, baudrate=%d, id=%d\n",
+		      __func__, gd->serial.using_pre_serial,
+		      gd->serial.addr, gd->serial.baudrate,
+		      gd->serial.id);
+	}
+
+	return 0;
+}
+#endif
+
 #if defined(CONFIG_USB_GADGET) && defined(CONFIG_USB_GADGET_DWC2_OTG)
 #include <fdt_support.h>
 #include <usb.h>

common/board_f.c

@@ -117,7 +117,11 @@ __weak void board_add_ram_info(int use_default)
 
 static int init_baud_rate(void)
 {
-	gd->baudrate = env_get_ulong("baudrate", 10, CONFIG_BAUDRATE);
+	if (gd && gd->serial.using_pre_serial)
+		gd->baudrate = env_get_ulong("baudrate", 10, gd->serial.baudrate);
+	else
+		gd->baudrate = env_get_ulong("baudrate", 10, CONFIG_BAUDRATE);
+
 	return 0;
 }
 
@@ -142,6 +146,16 @@ static int display_text_info(void)
 	return 0;
 }
 
+#if defined(CONFIG_ROCKCHIP_PRELOADER_SERIAL)
+static int announce_pre_serial(void)
+{
+	if (gd && gd->serial.using_pre_serial)
+		printf("PreSerial: %d\n", gd->serial.id);
+
+	return 0;
+}
+#endif
+
 static int announce_dram_init(void)
 {
 	puts("DRAM:  ");
@@ -803,6 +817,9 @@ static const init_fnc_t init_sequence_f[] = {
 #endif
 #if defined(CONFIG_HARD_SPI)
 	init_func_spi,
+#endif
+#if defined(CONFIG_ROCKCHIP_PRELOADER_SERIAL)
+	announce_pre_serial,
 #endif
 	announce_dram_init,
 	dram_init,		/* configure available RAM banks */

common/board_r.c

@@ -172,7 +172,22 @@ static int initr_reloc_global_data(void)
 
 static int initr_serial(void)
 {
+/*
+ * 1. Serial has been initialized in board_f.c => serial_init(), there is
+ *    no special reason to init it again;
+ *
+ * 2. Pre-serial works depending on aliases to get pre-serial phandle when
+ *    parse dtb. If CONFIG_USING_KERNEL_DTB is enabled, there are both kernel
+ *    dtb and U-Boot dtb aliases added into aliases_lookup, these nodes have
+ *    same names but different phanles(U-Boot nodes has high prior), this may
+ *    lead a wrong aliases node finding if try to get a node after kenrel dtb
+ *    unflattened, i.e. using U-Boot phandle to get kernel dtb node!!
+ *
+ *    Notice: of_alias_dump() is provided to dump all aliases node.
+ */
+#ifndef CONFIG_USING_KERNEL_DTB
 	serial_initialize();
+#endif
 	return 0;
 }
 

common/init/board_init.c

@@ -129,6 +129,14 @@ void board_init_f_init_reserve(ulong base)
 #endif
 }
 
+/*
+ * Board-specific Platform code can init serial earlier if needed
+ */
+__weak int board_init_f_init_serial(void)
+{
+	return 0;
+}
+
 /*
  * Board-specific Platform code can reimplement show_boot_progress () if needed
  */

drivers/core/of_access.c

@@ -804,5 +804,17 @@ struct device_node *of_alias_dump(void)
 
 struct device_node *of_get_stdout(void)
 {
+	struct device_node *np;
+
+	if (gd && gd->serial.using_pre_serial) {
+		np = of_alias_get_dev("serial", gd->serial.id);
+		if (!np)
+			printf("Can't find alias serial%d\n", gd->serial.id);
+		else
+			debug("Find alias serial: %s\n", np->full_name);
+
+		of_stdout = np;
+	}
+
 	return of_stdout;
 }

drivers/serial/ns16550.c

@@ -254,6 +254,13 @@ static inline void _debug_uart_init(void)
 	 */
 	baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
 					    CONFIG_BAUDRATE);
+
+	if (gd && gd->serial.using_pre_serial) {
+		com_port = (struct NS16550 *)gd->serial.addr;
+		baud_divisor = ns16550_calc_divisor(com_port,
+			CONFIG_DEBUG_UART_CLOCK, gd->serial.baudrate);
+	}
+
 	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
 	serial_dout(&com_port->mcr, UART_MCRVAL);
 	serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
@@ -268,6 +275,9 @@ static inline void _debug_uart_putc(int ch)
 {
 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 
+	if (gd && gd->serial.using_pre_serial)
+		com_port = (struct NS16550 *)gd->serial.addr;
+
 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
 		;
 	serial_dout(&com_port->thr, ch);
@@ -288,6 +298,13 @@ static inline void _debug_uart_init(void)
 
 	baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
 					    CONFIG_BAUDRATE);
+
+	if (gd && gd->serial.using_pre_serial) {
+		com_port = (struct NS16550 *)gd->serial.addr;
+		baud_divisor = ns16550_calc_divisor(com_port,
+			CONFIG_DEBUG_UART_CLOCK, gd->serial.baudrate);
+	}
+
 	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
 	serial_dout(&com_port->mdr1, 0x7);
 	serial_dout(&com_port->mcr, UART_MCRVAL);
@@ -304,6 +321,9 @@ static inline void _debug_uart_putc(int ch)
 {
 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 
+	if (gd && gd->serial.using_pre_serial)
+		com_port = (struct NS16550 *)gd->serial.addr;
+
 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
 		;
 	serial_dout(&com_port->thr, ch);
@@ -456,6 +476,10 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
 	plat->base = addr;
 #else
+
+	if (gd && gd->serial.using_pre_serial)
+		addr = gd->serial.addr;
+
 	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
 #endif
 

drivers/serial/serial-uclass.c

@@ -54,6 +54,23 @@ static int serial_check_stdout(const void *blob, struct udevice **devp)
 	}
 	if (node < 0)
 		node = fdt_path_offset(blob, "console");
+
+	if (gd && gd->serial.using_pre_serial) {
+		const char *serial_path;
+		char serial[12];
+
+		snprintf(serial, 12, "serial%d", gd->serial.id);
+		serial_path = fdt_get_alias(blob, serial);
+		if (serial_path) {
+			debug("Find alias %s, path: %s\n", serial, serial_path);
+			node = fdt_path_offset(blob, serial_path);
+			if (node < 0)
+				printf("Can't find %s by path\n", serial);
+		} else {
+			printf("Can't find alias %s\n", serial);
+		}
+	}
+
 	if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
 		return 0;
 

include/asm-generic/global_data.h

@@ -31,6 +31,13 @@ struct pm_ctx {
 	unsigned long suspend_regs[15];
 };
 
+struct pre_serial {
+	u32 using_pre_serial;
+	u32 id;
+	u32 baudrate;
+	ulong addr;
+};
+
 typedef struct global_data {
 	bd_t *bd;
 	unsigned long flags;
@@ -126,7 +133,7 @@ typedef struct global_data {
 #ifdef CONFIG_BOOTSTAGE_PRINTF_TIMESTAMP
 	int new_line;
 #endif
-
+	struct pre_serial serial;
 #ifdef CONFIG_LOG
 	int log_drop_count;		/* Number of dropped log messages */
 	int default_log_level;		/* For devices with no filters */

include/common.h

@@ -144,6 +144,11 @@ ulong board_init_f_alloc_reserve(ulong top);
  */
 void board_init_f_init_reserve(ulong base);
 
+/*
+ * Board-specific Platform code can init serial earlier if needed
+ */
+__weak int board_init_f_init_serial(void);
+
 /**
  * arch_setup_gd() - Set up the global_data pointer
  *