ARM: OMAP2+: Export SoC information to userspace

In some situations it is useful for userspace to
know some SoC-specific information. For example,
this may be used for deciding what kernel module to
use or how to better configure some settings etc.
This patch exports OMAP SoC information to userspace
using existing in Linux kernel SoC infrastructure.

This information can be read under
/sys/devices/socX directory

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@ti.com>
[tony@atomide.com: updated for multiplatform changes]
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/Kconfig

@@ -15,6 +15,7 @@ config ARCH_OMAP2PLUS
 	select OMAP_DM_TIMER
 	select PINCTRL
 	select PROC_DEVICETREE if PROC_FS
+	select SOC_BUS
 	select SPARSE_IRQ
 	select USE_OF
 	help

arch/arm/mach-omap2/common.h

@@ -110,6 +110,14 @@ void am35xx_init_late(void);
 void ti81xx_init_late(void);
 int omap2_common_pm_late_init(void);
 
+#ifdef CONFIG_SOC_BUS
+void omap_soc_device_init(void);
+#else
+static inline void omap_soc_device_init(void)
+{
+}
+#endif
+
 #if defined(CONFIG_SOC_OMAP2420) || defined(CONFIG_SOC_OMAP2430)
 void omap2xxx_restart(char mode, const char *cmd);
 #else

arch/arm/mach-omap2/id.c

@@ -18,6 +18,11 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_SOC_BUS
+#include <linux/sys_soc.h>
+#endif
 
 #include <asm/cputype.h>
 
@@ -583,3 +588,63 @@ void __init omap2_set_globals_tap(u32 class, void __iomem *tap)
 	else
 		tap_prod_id = 0x0208;
 }
+
+#ifdef CONFIG_SOC_BUS
+
+static const char const *omap_types[] = {
+	[OMAP2_DEVICE_TYPE_TEST]	= "TST",
+	[OMAP2_DEVICE_TYPE_EMU]		= "EMU",
+	[OMAP2_DEVICE_TYPE_SEC]		= "HS",
+	[OMAP2_DEVICE_TYPE_GP]		= "GP",
+	[OMAP2_DEVICE_TYPE_BAD]		= "BAD",
+};
+
+static const char * __init omap_get_family(void)
+{
+	if (cpu_is_omap24xx())
+		return kasprintf(GFP_KERNEL, "OMAP2");
+	else if (cpu_is_omap34xx())
+		return kasprintf(GFP_KERNEL, "OMAP3");
+	else if (cpu_is_omap44xx())
+		return kasprintf(GFP_KERNEL, "OMAP4");
+	else if (soc_is_omap54xx())
+		return kasprintf(GFP_KERNEL, "OMAP5");
+	else
+		return kasprintf(GFP_KERNEL, "Unknown");
+}
+
+static ssize_t omap_get_type(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	return sprintf(buf, "%s\n", omap_types[omap_type()]);
+}
+
+static struct device_attribute omap_soc_attr =
+	__ATTR(type,  S_IRUGO, omap_get_type,  NULL);
+
+void __init omap_soc_device_init(void)
+{
+	struct device *parent;
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return;
+
+	soc_dev_attr->machine  = soc_name;
+	soc_dev_attr->family   = omap_get_family();
+	soc_dev_attr->revision = soc_rev;
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR_OR_NULL(soc_dev)) {
+		kfree(soc_dev_attr);
+		return;
+	}
+
+	parent = soc_device_to_device(soc_dev);
+	if (!IS_ERR_OR_NULL(parent))
+		device_create_file(parent, &omap_soc_attr);
+}
+#endif /* CONFIG_SOC_BUS */

arch/arm/mach-omap2/io.c

@@ -389,6 +389,7 @@ static void __init omap_common_late_init(void)
 {
 	omap_mux_late_init();
 	omap2_common_pm_late_init();
+	omap_soc_device_init();
 }
 
 #ifdef CONFIG_SOC_OMAP2420