[PATCH v4 02/11] serial: earlycon: Fixup earlycon console name and index

From: Peter Hurley
Date: Tue Jan 12 2016 - 14:42:06 EST


Properly initialize the struct console 'name' and 'index' fields for
the registering earlycon. For earlycons w/o trailing numerals, the
index is set to 0; otherwise, the index is set to the value of the
trailing numeral. For example, the 'exynos4210' earlycon name == "exynos"
and index == 4210. Earlycons with embedded numerals will have all
non-trailing numerals as part of the name; for example, the 's3c2412'
earlycon name == "s3c" and index == 2412.

This ackward scheme was initially added for the uart8250 earlycon;
adopt this scheme for the other earlycon "drivers".

Introduce earlycon_init() which performs the string scanning and
initializes the name and index fields; encapsulate the other console
field initializations within.

Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/earlycon.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index d50b700..90b064f 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -27,9 +27,9 @@
#include <asm/serial.h>

static struct console early_con = {
- .name = "uart", /* 8250 console switch requires this name */
+ .name = "uart", /* fixed up at earlycon registration */
.flags = CON_PRINTBUFFER | CON_BOOT,
- .index = -1,
+ .index = 0,
};

static struct earlycon_device early_console_dev = {
@@ -53,6 +53,25 @@ static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
return base;
}

+static void __init earlycon_init(struct earlycon_device *device,
+ const char *name)
+{
+ struct console *earlycon = device->con;
+ const char *s;
+ size_t len;
+
+ /* scan backwards from end of string for first non-numeral */
+ for (s = name + strlen(name);
+ s > name && s[-1] >= '0' && s[-1] <= '9';
+ s--)
+ ;
+ if (*s)
+ earlycon->index = simple_strtoul(s, NULL, 10);
+ len = s - name;
+ strlcpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
+ earlycon->data = &early_console_dev;
+}
+
static int __init parse_options(struct earlycon_device *device, char *options)
{
struct uart_port *port = &device->port;
@@ -119,7 +138,7 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
if (port->mapbase)
port->membase = earlycon_map(port->mapbase, 64);

- early_console_dev.con->data = &early_console_dev;
+ earlycon_init(&early_console_dev, match->name);
err = match->setup(&early_console_dev, buf);
if (err < 0)
return err;
--
2.7.0