diff mbox

[1/2] sh-sci: Add CONFIG_SERIAL_EARLYCON support

Message ID 1447431743-16376-2-git-send-email-ulrich.hecht+renesas@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Ulrich Hecht Nov. 13, 2015, 4:22 p.m. UTC 
Hello.

"earlyprintk" is architecture specific option.
I think general "earlycon" option support more better.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
[uli: preserve other SCSCR bits when asserting RE and TE]
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
---
 drivers/tty/serial/Kconfig  |  6 ++++
 drivers/tty/serial/sh-sci.c | 71 +++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 74 insertions(+), 3 deletions(-)

Comments

Geert Uytterhoeven Nov. 16, 2015, 9:45 a.m. UTC | #1 
Hi Ulrich,

On Fri, Nov 13, 2015 at 5:22 PM, Ulrich Hecht
<ulrich.hecht+renesas@gmail.com> wrote:
> "earlyprintk" is architecture specific option.
> I think general "earlycon" option support more better.
>
> Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
> [uli: preserve other SCSCR bits when asserting RE and TE]

Thanks! That fixed it on Koelsch, too.

U-Boot uses the BRG and SCIF_CLK on Koelsch etc., while it doesn't on
Salvator-X. That's why it worked on R-Car Gen3 but not on Gen2.

> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>

The spinlock issues is still there, though, cfr.
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-August/364178.html

BUG: spinlock bad magic on CPU#0, swapper/0
 lock: sci_ports+0x0/0x3480, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
CPU: 0 PID: 0 Comm: swapper Not tainted
4.3.0-koelsch-12027-g4b94677ed7f4a3de-dirty #1974
Hardware name: Generic R8A7791 (Flattened Device Tree)
[<c00173a0>] (unwind_backtrace) from [<c0013094>] (show_stack+0x10/0x14)
[<c0013094>] (show_stack) from [<c01f1e38>] (dump_stack+0x70/0x8c)
[<c01f1e38>] (dump_stack) from [<c0070160>] (do_raw_spin_lock+0x20/0x190)
[<c0070160>] (do_raw_spin_lock) from [<c0266d28>]
(serial_console_write+0x4c/0x120)
[<c0266d28>] (serial_console_write) from [<c007334c>]
(call_console_drivers.constprop.13+0xc8/0xec)
[<c007334c>] (call_console_drivers.constprop.13) from [<c0074d78>]
(console_unlock+0x354/0x440)

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
--
To unsubscribe from this list: send the line "unsubscribe linux-sh" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 687b1ea..3326357 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -741,6 +741,12 @@  config SERIAL_SH_SCI_CONSOLE
 	depends on SERIAL_SH_SCI=y
 	select SERIAL_CORE_CONSOLE
 
+config SERIAL_SH_SCI_EARLYCON
+	bool "Support for early console on SuperH SCI(F)"
+	depends on SERIAL_SH_SCI=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+
 config SERIAL_SH_SCI_DMA
 	bool "DMA support"
 	depends on SERIAL_SH_SCI && SH_DMAE
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 1b2f894..da4300b 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -489,7 +489,8 @@  static void sci_port_disable(struct sci_port *sci_port)
 	pm_runtime_put_sync(sci_port->port.dev);
 }
 
-#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) \
+	|| defined(CONFIG_SERIAL_EARLYCON)
 
 #ifdef CONFIG_CONSOLE_POLL
 static int sci_poll_get_char(struct uart_port *port)
@@ -2345,7 +2346,7 @@  static void sci_cleanup_single(struct sci_port *port)
 	pm_runtime_disable(port->port.dev);
 }
 
-#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
+#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || defined(CONFIG_SERIAL_EARLYCON)
 static void serial_console_putchar(struct uart_port *port, int ch)
 {
 	sci_poll_put_char(port, ch);
@@ -2365,9 +2366,12 @@  static void serial_console_write(struct console *co, const char *s,
 	int locked = 1;
 
 	local_irq_save(flags);
+#if defined(SUPPORT_SYSRQ)
 	if (port->sysrq)
 		locked = 0;
-	else if (oops_in_progress)
+	else
+#endif
+	if (oops_in_progress)
 		locked = spin_trylock(&port->lock);
 	else
 		spin_lock(&port->lock);
@@ -2725,6 +2729,67 @@  static void __exit sci_exit(void)
 early_platform_init_buffer("earlyprintk", &sci_driver,
 			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
 #endif
+#ifdef CONFIG_SERIAL_EARLYCON
+static struct __init plat_sci_port port_cfg;
+
+static int __init early_console_setup(struct earlycon_device *device,
+				      int type)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.serial_in = sci_serial_in;
+	device->port.serial_out	= sci_serial_out;
+	device->port.type = type;
+	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
+	sci_ports[0].cfg = &port_cfg;
+	sci_ports[0].cfg->type = type;
+	sci_probe_regmap(sci_ports[0].cfg);
+	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR) |
+			 SCSCR_RE | SCSCR_TE;
+	sci_serial_out(&sci_ports[0].port, SCSCR, port_cfg.scscr);
+
+	device->con->write = serial_console_write;
+	return 0;
+}
+static int __init sci_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCI);
+}
+static int __init scif_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCIF);
+}
+static int __init scifa_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCIFA);
+}
+static int __init scifb_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_SCIFB);
+}
+static int __init hscif_early_console_setup(struct earlycon_device *device,
+					  const char *opt)
+{
+	return early_console_setup(device, PORT_HSCIF);
+}
+
+EARLYCON_DECLARE(sci, sci_early_console_setup);
+OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
+EARLYCON_DECLARE(scif, scif_early_console_setup);
+OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
+EARLYCON_DECLARE(scifa, scifa_early_console_setup);
+OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
+EARLYCON_DECLARE(scifb, scifb_early_console_setup);
+OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
+EARLYCON_DECLARE(hscif, hscif_early_console_setup);
+OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
+#endif
+
 module_init(sci_init);
 module_exit(sci_exit);