dm: serial: support always use uart debug mode

In this mode, uart debug is initialized depends on
configuration from pre-loader or CONFIG_UART_DEBUG_.

The serial is not care about dts "stdout-path" and
not register into console framework any more. It's
nice to use pre-loader serial and make serial easy
to configure.

Signed-off-by: Joseph Chen <chenjh@rock-chips.com>
Change-Id: If4c68229d76b6f1710a35e3ef9a2a91cb306fa9c

arch/arm/lib/crt0.S

@@ -84,9 +84,8 @@ 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
+	bl	board_init_f_boot_flags
 
-	mov	r0, #0
 	bl	board_init_f
 
 #if ! defined(CONFIG_SPL_BUILD)

arch/arm/lib/crt0_64.S

@@ -101,9 +101,8 @@ 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
+	bl	board_init_f_boot_flags
 
-	mov	x0, #0
 	bl	board_init_f
 
 #if (defined(CONFIG_SPL_BUILD) && !defined(CONFIG_TPL_BUILD) && !defined(CONFIG_SPL_SKIP_RELOCATE)) || \

common/board_f.c

@@ -119,8 +119,8 @@ __weak void board_add_ram_info(int use_default)
 
 static int init_baud_rate(void)
 {
-	if (gd && gd->serial.using_pre_serial)
+	if (gd && gd->serial.baudrate)
-		gd->baudrate = env_get_ulong("baudrate", 10, gd->serial.baudrate);
+		gd->baudrate = gd->serial.baudrate;
 	else
 		gd->baudrate = env_get_ulong("baudrate", 10, CONFIG_BAUDRATE);
 
@@ -148,15 +148,22 @@ static int display_text_info(void)
 	return 0;
 }
 
-#if defined(CONFIG_ROCKCHIP_PRELOADER_SERIAL)
+static int announce_serial(void)
-static int announce_pre_serial(void)
 {
 	if (gd && gd->serial.using_pre_serial)
-		printf("PreSerial: %d\n", gd->serial.id);
+		printf("PreSerial: %d, ", gd->serial.id);
+	else
+		printf("Serial: ");
+
+#ifdef CONFIG_DEBUG_UART_ALWAYS
+	printf("raw");
+#else
+	printf("console");
+#endif
+	printf(", 0x%lx\n", gd->serial.addr);
 
 	return 0;
 }
-#endif
 
 static int announce_dram_init(void)
 {
@@ -861,9 +868,8 @@ static const init_fnc_t init_sequence_f[] = {
 #if defined(CONFIG_HARD_SPI)
 	init_func_spi,
 #endif
-#if defined(CONFIG_ROCKCHIP_PRELOADER_SERIAL)
+	announce_serial,
-	announce_pre_serial,
+
-#endif
 	announce_dram_init,
 	dram_init,		/* configure available RAM banks */
 #ifdef CONFIG_POST
@@ -954,10 +960,6 @@ void board_init_f(ulong boot_flags)
 	gd->flags = boot_flags;
 	gd->have_console = 0;
 
-#if defined(CONFIG_DISABLE_CONSOLE)
-	gd->flags |= GD_FLG_DISABLE_CONSOLE;
-#endif
-
 	if (initcall_run_list(init_sequence_f))
 		hang();
 

common/console.c

@@ -408,10 +408,8 @@ int fprintf(int file, const char *fmt, ...)
 
 int getc(void)
 {
-#ifdef CONFIG_DISABLE_CONSOLE
+	if (!gd || gd->flags & GD_FLG_DISABLE_CONSOLE)
-	if (gd->flags & GD_FLG_DISABLE_CONSOLE)
 		return 0;
-#endif
 
 	if (!gd->have_console)
 		return 0;
@@ -436,10 +434,8 @@ int getc(void)
 
 int tstc(void)
 {
-#ifdef CONFIG_DISABLE_CONSOLE
+	if (!gd || gd->flags & GD_FLG_DISABLE_CONSOLE)
-	if (gd->flags & GD_FLG_DISABLE_CONSOLE)
 		return 0;
-#endif
 
 	if (!gd->have_console)
 		return 0;
@@ -460,10 +456,8 @@ int tstc(void)
 
 void flushc(void)
 {
-#ifdef CONFIG_DISABLE_CONSOLE
+	if (!gd || gd->flags & GD_FLG_DISABLE_CONSOLE)
-	if (gd->flags & GD_FLG_DISABLE_CONSOLE)
 		return;
-#endif
 
 	if (gd->flags & GD_FLG_DEVINIT)
 		fclear(stdout);
@@ -520,10 +514,8 @@ static inline void print_pre_console_buffer(int flushpoint) {}
 
 void putc(const char c)
 {
-#ifdef CONFIG_DISABLE_CONSOLE
 	if (!gd || gd->flags & GD_FLG_DISABLE_CONSOLE)
 		return;
-#endif
 
 #ifdef CONFIG_DEBUG_UART
 	/* if we don't have a console yet, use the debug UART */

common/init/board_init.c

@@ -130,10 +130,15 @@ void board_init_f_init_reserve(ulong base)
 }
 
 /*
- * Board-specific Platform code can init serial earlier if needed
+ * Board-specific Platform code can init boot flags if needed
  */
-__weak int board_init_f_init_serial(void)
+__weak int board_init_f_boot_flags(void)
 {
+	gd->baudrate = CONFIG_BAUDRATE;
+	gd->serial.baudrate = CONFIG_BAUDRATE;
+	gd->serial.addr = CONFIG_DEBUG_UART_BASE;
+	gd->serial.using_pre_serial = 0;
+
 	return 0;
 }
 

drivers/serial/Kconfig

@@ -346,6 +346,11 @@ config DEBUG_UART_SKIP_INIT
 	  Select this if the UART you want to use for debug output is already
 	  initialized by the time U-Boot starts its execution.
 
+config DEBUG_UART_ALWAYS
+	bool "Always use debug UART mode"
+	help
+	  Say y to always use debug UART, skip complicated console UART register.
+
 config ALTERA_JTAG_UART
 	bool "Altera JTAG UART support"
 	depends on DM_SERIAL

drivers/serial/ns16550.c

@@ -246,6 +246,12 @@ static inline void _debug_uart_init(void)
 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 	int baud_divisor;
 
+	if (gd && gd->flags & GD_FLG_DISABLE_CONSOLE)
+		return;
+
+	if (gd && gd->serial.using_pre_serial)
+		return;
+
 	/*
 	 * We copy the code from above because it is already horribly messy.
 	 * Trying to refactor to nicely remove the duplication doesn't seem
@@ -266,13 +272,109 @@ static inline void _debug_uart_init(void)
 
 static inline void _debug_uart_putc(int ch)
 {
-	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
+	struct NS16550 *com_port;
+
+	if (gd && gd->flags & GD_FLG_DISABLE_CONSOLE)
+		return;
+
+	if (gd && gd->serial.addr)
+		com_port = (struct NS16550 *)gd->serial.addr;
+	else
+		com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
 
 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
 		;
 	serial_dout(&com_port->thr, ch);
 }
 
+static inline int _debug_uart_getc(void)
+{
+	struct NS16550 *com_port;
+
+	if (gd && gd->flags & GD_FLG_DISABLE_CONSOLE)
+		return 0;
+
+	if (gd && gd->serial.addr)
+		com_port = (struct NS16550 *)gd->serial.addr;
+	else
+		com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
+
+	while (!(serial_din(&com_port->lsr) & UART_LSR_DR))
+		;
+
+	return serial_din(&com_port->rbr);
+}
+
+static inline int _debug_uart_tstc(int input)
+{
+	struct NS16550 *com_port;
+
+	if (gd && gd->flags & GD_FLG_DISABLE_CONSOLE)
+		return 0;
+
+	if (gd && gd->serial.addr)
+		com_port = (struct NS16550 *)gd->serial.addr;
+	else
+		com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
+
+	if (input)
+		return serial_din(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
+	else
+		return serial_din(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
+}
+
+static inline int _debug_uart_clrc(void)
+{
+	struct NS16550 *com_port;
+
+	if (gd && gd->flags & GD_FLG_DISABLE_CONSOLE)
+		return 0;
+
+	if (gd && gd->serial.addr)
+		com_port = (struct NS16550 *)gd->serial.addr;
+	else
+		com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
+
+	/*
+	 * Wait fifo flush.
+	 *
+	 * UART_USR: bit2 trans_fifo_empty:
+	 *	0 = Transmit FIFO is not empty
+	 *	1 = Transmit FIFO is empty
+	 */
+	while (!(serial_din(&com_port->rbr + 0x1f) & 0x04))
+		;
+
+	return 0;
+}
+
+/* should use gd->baudrate, it can be updated by env callback: on_baudrate() */
+static inline int _debug_uart_setbrg(void)
+{
+	struct NS16550 *com_port;
+	int baud_divisor;
+
+	if (gd && gd->flags & GD_FLG_DISABLE_CONSOLE)
+		return 0;
+
+	if (gd && gd->serial.addr) {
+		com_port = (struct NS16550 *)gd->serial.addr;
+		baud_divisor = ns16550_calc_divisor(com_port,
+			CONFIG_DEBUG_UART_CLOCK, gd->baudrate);
+	} else {
+		com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
+		baud_divisor = ns16550_calc_divisor(com_port,
+			CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
+	}
+
+	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
+	serial_dout(&com_port->dll, baud_divisor & 0xff);
+	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
+	serial_dout(&com_port->lcr, UART_LCRVAL);
+
+	return 0;
+}
+
 DEBUG_UART_FUNCS
 
 #endif
@@ -318,8 +420,15 @@ static int ns16550_serial_putc(struct udevice *dev, const char ch)
 {
 	struct NS16550 *const com_port = dev_get_priv(dev);
 
-	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
+	/*
-		return -EAGAIN;
+	 * Use fifo function.
+	 *
+	 * UART_USR: bit1 trans_fifo_not_full:
+	 *	0 = Transmit FIFO is full;
+	 *	1 = Transmit FIFO is not full;
+	 */
+	while (!(serial_in(&com_port->rbr + 0x1f) & 0x02))
+		;
 	serial_out(ch, &com_port->thr);
 
 	/*
@@ -367,6 +476,23 @@ static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
 	return 0;
 }
 
+static int ns16550_serial_clear(struct udevice *dev)
+{
+	struct NS16550 *const com_port = dev_get_priv(dev);
+
+	/*
+	 * Wait fifo flush.
+	 *
+	 * UART_USR: bit2 trans_fifo_empty:
+	 *	0 = Transmit FIFO is not empty
+	 *	1 = Transmit FIFO is empty
+	 */
+	while (!(serial_in(&com_port->rbr + 0x1f) & 0x04))
+		;
+
+	return 0;
+}
+
 int ns16550_serial_probe(struct udevice *dev)
 {
 	struct NS16550 *const com_port = dev_get_priv(dev);
@@ -442,7 +568,7 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 		if (!IS_ERR_VALUE(err))
 			plat->clock = err;
 	} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
-		debug("ns16550 failed to get clock\n");
+		printf("ns16550 failed to get clock, err=%d\n", err);
 		return err;
 	}
 
@@ -467,8 +593,10 @@ const struct dm_serial_ops ns16550_serial_ops = {
 	.pending = ns16550_serial_pending,
 	.getc = ns16550_serial_getc,
 	.setbrg = ns16550_serial_setbrg,
+	.clear = ns16550_serial_clear,
 };
 
+#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
 /*
  * Please consider existing compatible strings before adding a new
@@ -491,8 +619,6 @@ static const struct udevice_id ns16550_serial_ids[] = {
 };
 #endif /* OF_CONTROL && !OF_PLATDATA */
 
-#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
-
 /* TODO(sjg@chromium.org): Integrate this into a macro like CONFIG_IS_ENABLED */
 #if !defined(CONFIG_TPL_BUILD) || defined(CONFIG_TPL_DM_SERIAL)
 U_BOOT_DRIVER(ns16550_serial) = {

drivers/serial/serial-uclass.c

@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <debug_uart.h>
 #include <dm.h>
 #include <environment.h>
 #include <errno.h>
@@ -27,6 +28,7 @@ static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
 #endif
 
+#ifndef CONFIG_DEBUG_UART_ALWAYS
 static int serial_check_stdout(const void *blob, struct udevice **devp)
 {
 	int node;
@@ -134,6 +136,9 @@ int serial_init(void)
 
 	return 0;
 }
+#else
+int serial_init(void) { return 0; }
+#endif
 
 /* Called after relocation */
 void serial_initialize(void)
@@ -184,6 +189,14 @@ static int __serial_tstc(struct udevice *dev)
 	return 1;
 }
 
+static void __serial_clear(struct udevice *dev)
+{
+	struct dm_serial_ops *ops = serial_get_ops(dev);
+
+	if (ops->clear)
+		ops->clear(dev);
+}
+
 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
 static int _serial_tstc(struct udevice *dev)
 {
@@ -226,42 +239,108 @@ void serial_putc(char ch)
 {
 	if (gd->cur_serial_dev)
 		_serial_putc(gd->cur_serial_dev, ch);
+	else
+		printch(ch);
 }
 
 void serial_puts(const char *str)
 {
 	if (gd->cur_serial_dev)
 		_serial_puts(gd->cur_serial_dev, str);
+	else
+		printascii(str);
 }
 
 int serial_getc(void)
 {
-	if (!gd->cur_serial_dev)
+	if (gd->cur_serial_dev)
-		return 0;
+		return _serial_getc(gd->cur_serial_dev);
-
+	else
-	return _serial_getc(gd->cur_serial_dev);
+		return debug_uart_getc();
 }
 
 int serial_tstc(void)
 {
-	if (!gd->cur_serial_dev)
+	if (gd->cur_serial_dev)
-		return 0;
+		return _serial_tstc(gd->cur_serial_dev);
-
+	else
-	return _serial_tstc(gd->cur_serial_dev);
+		return debug_uart_tstc();
 }
 
 void serial_setbrg(void)
 {
 	struct dm_serial_ops *ops;
 
-	if (!gd->cur_serial_dev)
+	if (!gd->cur_serial_dev) {
+		debug_uart_setbrg();
 		return;
+	}
 
 	ops = serial_get_ops(gd->cur_serial_dev);
 	if (ops->setbrg)
 		ops->setbrg(gd->cur_serial_dev, gd->baudrate);
 }
 
+void serial_clear(void)
+{
+	if (gd->cur_serial_dev)
+		__serial_clear(gd->cur_serial_dev);
+	else
+		debug_uart_clrc();
+}
+
+void serial_dev_putc(struct udevice *dev, char ch)
+{
+	if (!dev)
+		return;
+
+	_serial_putc(dev, ch);
+}
+
+void serial_dev_puts(struct udevice *dev, const char *str)
+{
+	if (!dev)
+		return;
+
+	_serial_puts(dev, str);
+}
+
+int serial_dev_getc(struct udevice *dev)
+{
+	if (!dev)
+		return 0;
+
+	return _serial_getc(dev);
+}
+
+int serial_dev_tstc(struct udevice *dev)
+{
+	if (!dev)
+		return 0;
+
+	return _serial_tstc(dev);
+}
+
+void serial_dev_setbrg(struct udevice *dev, int baudrate)
+{
+	struct dm_serial_ops *ops;
+
+	if (!dev)
+		return;
+
+	ops = serial_get_ops(dev);
+	if (ops->setbrg)
+		ops->setbrg(dev, baudrate);
+}
+
+void serial_dev_clear(struct udevice *dev)
+{
+	if (!dev)
+		return;
+
+	__serial_clear(dev);
+}
+
 void serial_stdio_init(void)
 {
 }

include/asm-generic/global_data.h

@@ -33,6 +33,7 @@ struct pm_ctx {
 
 struct pre_serial {
 	u32 using_pre_serial;
+	u32 enable;
 	u32 id;
 	u32 baudrate;
 	ulong addr;

include/common.h

@@ -149,7 +149,7 @@ 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);
+__weak int board_init_f_boot_flags(void);
 
 /**
  * arch_setup_gd() - Set up the global_data pointer

include/debug_uart.h

@@ -76,6 +76,10 @@ static inline void board_debug_uart_init(void)
  * @ch:		Character to output
  */
 void printch(int ch);
+int debug_uart_getc(void);
+int debug_uart_tstc(void);
+int debug_uart_clrc(void);
+int debug_uart_setbrg(void);
 
 /**
  * printascii() - Output an ASCII string to the debug UART
@@ -145,6 +149,26 @@ void printdec(uint value);
 	{ \
 		_printch(ch); \
 	} \
+\
+	int debug_uart_getc(void)\
+	{ \
+		return _debug_uart_getc(); \
+	} \
+\
+	int debug_uart_tstc(void)\
+	{ \
+		return _debug_uart_tstc(true); \
+	} \
+\
+	int debug_uart_clrc(void)\
+	{ \
+		return _debug_uart_clrc(); \
+	} \
+\
+	int debug_uart_setbrg(void)\
+	{ \
+		return _debug_uart_setbrg(); \
+	} \
 \
 	void printascii(const char *str) \
 	{ \