[PATCH 03/05] sh-sci: Extend sh-sci driver with early console

[Magnus Damm <magnus.damm@gmail.com>]

From: Magnus Damm <damm@opensource.se>

Add early serial console support to the sh-sci driver
using early platform devices and "earlyprintk". To use
this feature the early platform devices must be broken
out to one device per port and the desired port should
be selected on the kernel command line like:
"earlyprintk=sh-sci.N[,baudrate][,keep]"

We may want to ditch all the #ifdefery, but it may
save some space as-is.

Signed-off-by: Magnus Damm <damm@opensource.se>
---

 arch/sh/Kconfig.debug         |    1 
 arch/sh/kernel/early_printk.c |   10 -------
 arch/sh/kernel/setup.c        |    5 +++
 drivers/serial/sh-sci.c       |   56 ++++++++++++++++++++++++++++++++++-------
 4 files changed, 54 insertions(+), 18 deletions(-)

--- 0001/arch/sh/Kconfig.debug
+++ work/arch/sh/Kconfig.debug	2009-11-05 22:49:11.000000000 +0900
@@ -21,6 +21,7 @@ config SH_STANDARD_BIOS
 
 config EARLY_SCIF_CONSOLE
 	bool "Use early SCIF console"
+	select SERIAL_SH_SCI
 	help
 	  This enables an early console using a fixed SCIF port. This can
 	  be used by platforms that are either not running the SH
--- 0001/arch/sh/kernel/early_printk.c
+++ work/arch/sh/kernel/early_printk.c	2009-11-05 22:43:07.000000000 +0900
@@ -191,15 +191,7 @@ static void scif_sercon_init(char *s)
  * Setup a default console, if more than one is compiled in, rely on the
  * earlyprintk= parsing to give priority.
  */
-static struct console *early_console -#ifdef CONFIG_SH_STANDARD_BIOS
-	&bios_console
-#elif defined(CONFIG_EARLY_SCIF_CONSOLE)
-	&scif_console
-#else
-	NULL
-#endif
-	;
+static struct console *early_console;
 
 static int __init setup_early_printk(char *buf)
 {
--- 0001/arch/sh/kernel/setup.c
+++ work/arch/sh/kernel/setup.c	2009-11-05 22:43:07.000000000 +0900
@@ -423,6 +423,11 @@ void __init setup_arch(char **cmdline_p)
 
 	plat_early_device_setup();
 
+#ifdef CONFIG_EARLY_PRINTK
+	/* Let earlyprintk output early console messages */
+	early_platform_driver_probe("earlyprintk", 1, 1);
+#endif
+
 	sh_mv_setup();
 
 	/*
--- 0003/drivers/serial/sh-sci.c
+++ work/drivers/serial/sh-sci.c	2009-11-05 22:50:37.000000000 +0900
@@ -1085,10 +1085,12 @@ static void __devinit sci_init_single(st
 #endif
 	sci_port->port.uartclk	= CONFIG_CPU_CLOCK;
 #elif defined(CONFIG_HAVE_CLK)
-	sci_port->iclk		= p->clk ? clk_get(&dev->dev, p->clk) : NULL;
-	sci_port->dclk		= clk_get(&dev->dev, "peripheral_clk");
-	sci_port->enable	= sci_clk_enable;
-	sci_port->disable	= sci_clk_disable;
+	if (dev) {
+		sci_port->iclk = p->clk ? clk_get(&dev->dev, p->clk) : NULL;
+		sci_port->dclk = clk_get(&dev->dev, "peripheral_clk");
+		sci_port->enable = sci_clk_enable;
+		sci_port->disable = sci_clk_disable;
+	}
 #else
 #error "Need a valid uartclk"
 #endif
@@ -1102,11 +1104,12 @@ static void __devinit sci_init_single(st
 
 	sci_port->port.irq	= p->irqs[SCIx_TXI_IRQ];
 	sci_port->port.flags	= p->flags;
-	sci_port->port.dev	= &dev->dev;
 	sci_port->type		= sci_port->port.type = p->type;
 
 	memcpy(&sci_port->irqs, &p->irqs, sizeof(p->irqs));
 
+	if (dev)
+		sci_port->port.dev	= &dev->dev;
 }
 
 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
@@ -1147,7 +1150,7 @@ static void serial_console_write(struct 
 		sci_port->disable(port);
 }
 
-static int __init serial_console_setup(struct console *co, char *options)
+static int __devinit serial_console_setup(struct console *co, char *options)
 {
 	struct sci_port *sci_port;
 	struct uart_port *port;
@@ -1165,9 +1168,14 @@ static int __init serial_console_setup(s
 	if (co->index >= SCI_NPORTS)
 		co->index = 0;
 
-	sci_port = &sci_ports[co->index];
-	port = &sci_port->port;
-	co->data = port;
+	if (co->data) {
+		port = co->data;
+		sci_port = to_sci_port(port);
+	} else {
+		sci_port = &sci_ports[co->index];
+		port = &sci_port->port;
+		co->data = port;
+	}
 
 	/*
 	 * Also need to check port->type, we don't actually have any
@@ -1211,6 +1219,17 @@ static int __init sci_console_init(void)
 	return 0;
 }
 console_initcall(sci_console_init);
+
+#ifdef CONFIG_EARLY_SCIF_CONSOLE
+static struct sci_port early_serial_port;
+static struct console early_serial_console = {
+	.name           = "early_ttySC",
+	.write          = serial_console_write,
+	.flags          = CON_PRINTBUFFER,
+};
+static char early_serial_buf[32];
+#endif
+
 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
 
 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
@@ -1299,6 +1318,21 @@ static int __devinit sci_probe(struct pl
 	struct sh_sci_priv *priv;
 	int i, ret = -EINVAL;
 
+#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_EARLY_SCIF_CONSOLE)
+	if (is_early_platform_device(dev)) {
+		if (dev->id = -1)
+			return -ENOTSUPP;
+		early_serial_console.index = dev->id;
+		early_serial_console.data = &early_serial_port.port;
+		sci_init_single(NULL, &early_serial_port, dev->id, p);
+		serial_console_setup(&early_serial_console, early_serial_buf);
+		if (!strstr(early_serial_buf, "keep"))
+			early_serial_console.flags |= CON_BOOT;
+		register_console(&early_serial_console);
+		return 0;
+	}
+#endif
+
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
@@ -1400,6 +1434,10 @@ static void __exit sci_exit(void)
 	uart_unregister_driver(&sci_uart_driver);
 }
 
+#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_EARLY_SCIF_CONSOLE)
+early_platform_init_buffer("earlyprintk", &sci_driver,
+			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
+#endif
 module_init(sci_init);
 module_exit(sci_exit);