Driver Core: Early platform driver buffer

Add early_platform_init_buffer() support and update the
early platform driver code to allow passing parameters
to the driver on the kernel command line.

early_platform_init_buffer() simply allows early platform
drivers to provide a pointer and length to a memory area
where the remaining part of the kernel command line option
will be stored.

Needed to pass baud rate and other serial port options
to the reworked early serial console code on SuperH.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 22 insertions, 7 deletions

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 4fa954b07ac4..9d2ee25deaf5 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1000,7 +1000,7 @@ static __initdata LIST_HEAD(early_platform_device_list);
 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
 					  char *buf)
 {
-	unsigned long index;
+	char *tmp;
 	int n;
 
 	/* Simply add the driver to the end of the global list.
@@ -1019,13 +1019,28 @@ int __init early_platform_driver_register(struct early_platform_driver *epdrv,
 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
 		list_move(&epdrv->list, &early_platform_driver_list);
 
-		if (!strcmp(buf, epdrv->pdrv->driver.name))
+		/* Allow passing parameters after device name */
+		if (buf[n] == '\0' || buf[n] == ',')
 			epdrv->requested_id = -1;
-		else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10,
-							 &index) == 0)
-			epdrv->requested_id = index;
-		else
-			epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
+		else {
+			epdrv->requested_id = simple_strtoul(&buf[n + 1],
+							     &tmp, 10);
+
+			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
+				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
+				n = 0;
+			} else
+				n += strcspn(&buf[n + 1], ",") + 1;
+		}
+
+		if (buf[n] == ',')
+			n++;
+
+		if (epdrv->bufsize) {
+			memcpy(epdrv->buffer, &buf[n],
+			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
+			epdrv->buffer[epdrv->bufsize - 1] = '\0';
+		}
 	}
 
 	return 0;