ARM: OMAP: Add support for a procfs entry for component versions

Some bootloaders have the ability to send information about the
various component versions (e.g. HW revision, bootloader version)
through the ATAG mechanism. This patch implements a procfs entry
for reading such information.
Signed-off-by: Juha Yrjölä <juha.yrjola@nokia.com>

arch/arm/plat-omap/Kconfig

@@ -47,6 +47,14 @@ config OMAP_BOOT_REASON
           Say Y, if you want to have a procfs entry for reading the boot
           reason in user-space.
 
+config OMAP_COMPONENT_VERSION
+	bool "Support for component version display"
+	depends on OMAP_BOOT_TAG && PROC_FS
+	default n
+	help
+	  Say Y, if you want to have a procfs entry for reading component
+	  versions (supplied by the bootloader) in user-space.
+
 config OMAP_GPIO_SWITCH
 	bool "GPIO switch support"
         depends on OMAP_BOOT_TAG

arch/arm/plat-omap/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_OMAP_STI) += sti/
 obj-$(CONFIG_CPU_FREQ) += cpu-omap.o
 obj-$(CONFIG_OMAP_DM_TIMER) += dmtimer.o
 obj-$(CONFIG_OMAP_BOOT_REASON) += bootreason.o
+obj-$(CONFIG_OMAP_COMPONENT_VERSION) += component-version.o
 obj-$(CONFIG_OMAP_GPIO_SWITCH) += gpio-switch.o
 
 # DSP subsystem

arch/arm/plat-omap/component-version.c

+/*
+ *  linux/arch/arm/plat-omap/component-version.c
+ *
+ *  Copyright (C) 2005 Nokia Corporation
+ *  Written by Juha Yrjl <juha.yrjola@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/proc_fs.h>
+#include <asm/arch/board.h>
+#include <asm/arch/board-nokia.h>
+
+static int component_version_read_proc(char *page, char **start, off_t off,
+				       int count, int *eof, void *data)
+{
+	int len, i;
+	const struct omap_version_config *ver;
+	char *p;
+
+	i = 0;
+	p = page;
+	while ((ver = omap_get_nr_config(OMAP_TAG_VERSION_STR,
+					 struct omap_version_config, i)) != NULL) {
+		p += sprintf(p, "%-12s%s\n", ver->component, ver->version);
+		i++;
+	}
+
+	len = (p - page) - off;
+	if (len < 0)
+		len = 0;
+
+	*eof = (len <= count) ? 1 : 0;
+	*start = page + off;
+
+	return len;
+}
+
+static int __init component_version_init(void)
+{
+	if (omap_get_config(OMAP_TAG_VERSION_STR, struct omap_version_config) == NULL)
+		return -ENODEV;
+	if (!create_proc_read_entry("component_version", S_IRUGO, NULL,
+				    component_version_read_proc, NULL))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void __exit component_version_exit(void)
+{
+	remove_proc_entry("component_version", NULL);
+}
+
+late_initcall(component_version_init);
+module_exit(component_version_exit);
+
+MODULE_AUTHOR("Juha Yrjl <juha.yrjola@nokia.com>");
+MODULE_DESCRIPTION("Component version driver");
+MODULE_LICENSE("GPL");