ARM: bcm2835: Set Serial number and Revision

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

The VideoCore bootloader passes in Serial number and
Revision number through Device Tree. Make these available to
userspace through /proc/cpuinfo.

Mainline status:

There is a commit in linux-next that standardize passing the serial
number through Device Tree (string: /serial-number):
ARM: 8355/1: arch: Show the serial number from devicetree in cpuinfo

There was an attempt to do the same with the revision number, but it
didn't get in:
[PATCH v2 1/2] arm: devtree: Set system_rev from DT revision
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm/mach-bcm/board_bcm2835.c

@@ -6,12 +6,25 @@
 #include <linux/init.h>
 #include <linux/irqchip.h>
 #include <linux/of_address.h>
+#include <asm/system_info.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
 
 #include "platsmp.h"
 
+static void __init bcm2835_init(void)
+{
+	struct device_node *np = of_find_node_by_path("/system");
+	u32 val;
+	u64 val64;
+
+	if (!of_property_read_u32(np, "linux,revision", &val))
+		system_rev = val;
+	if (!of_property_read_u64(np, "linux,serial", &val64))
+		system_serial_low = val64;
+}
+
 static const char * const bcm2835_compat[] = {
 #ifdef CONFIG_ARCH_MULTI_V6
 	"brcm,bcm2835",
@@ -24,6 +37,7 @@ static const char * const bcm2835_compat[] = {
 };
 
 DT_MACHINE_START(BCM2835, "BCM2835")
+	.init_machine = bcm2835_init,
 	.dt_compat = bcm2835_compat,
 	.smp = smp_ops(bcm2836_smp_ops),
 MACHINE_END