[RFC 2/2] ARM: vf610: Add SoC bus support for Vybrid

[Sanchayan Maity]

Implements SoC bus support to export SoC specific information. Read
the unique SoC ID from the Vybrid On Chip One Time Programmable (OCOTP)
controller, SoC specific information from the Miscellaneous System
Control Module (MSCM), revision from the ROM revision register and
expose it via the SoC bus infrastructure.

Signed-off-by: Sanchayan Maity <maitysanchayan at gmail.com>
---
 arch/arm/mach-imx/mach-vf610.c | 76 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 75 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/mach-vf610.c b/arch/arm/mach-imx/mach-vf610.c
index 1ba7738..74681f1 100644
--- a/arch/arm/mach-imx/mach-vf610.c
+++ b/arch/arm/mach-imx/mach-vf610.c
@@ -9,13 +9,87 @@
 
 #include <linux/of_platform.h>
 #include <linux/irqchip.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/random.h>
+#include <linux/io.h>
 #include <asm/mach/arch.h>
 #include <asm/hardware/cache-l2x0.h>
 #include "common.h"
 
+#define OCOTP_CFG0_OFFSET      0x00000410
+#define OCOTP_CFG1_OFFSET      0x00000420
+#define MSCM_CPxCOUNT_OFFSET   0x0000002C
+#define MSCM_CPxCFG1_OFFSET    0x00000014
+#define ROM_REVISION_REGISTER  0x00000080
+
 static void __init vf610_init_machine(void)
 {
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	struct regmap *ocotp_regmap, *mscm_regmap;
+	struct soc_device_attribute *soc_dev_attr;
+	struct device *parent = NULL;
+	struct soc_device *soc_dev;
+	char soc_type[] = "xx0";
+	void __iomem *rom_rev;
+	u32 cpxcount, cpxcfg1;
+	u32 soc_id1, soc_id2;
+	u64 soc_id;
+
+	ocotp_regmap = syscon_regmap_lookup_by_compatible("fsl,vf610-ocotp");
+	if (IS_ERR(ocotp_regmap)) {
+		pr_err("regmap lookup for octop failed\n");
+		goto out;
+	}
+
+	mscm_regmap = syscon_regmap_lookup_by_compatible("fsl,vf610-mscm-cpucfg");
+	if (IS_ERR(mscm_regmap)) {
+		pr_err("regmap lookup for mscm failed");
+		goto out;
+	}
+
+	regmap_read(ocotp_regmap, OCOTP_CFG0_OFFSET, &soc_id1);
+	regmap_read(ocotp_regmap, OCOTP_CFG1_OFFSET, &soc_id2);
+
+	soc_id = (u64) soc_id1 << 32 | soc_id2;
+	add_device_randomness(&soc_id, sizeof(soc_id));
+
+	regmap_read(mscm_regmap, MSCM_CPxCOUNT_OFFSET, &cpxcount);
+	regmap_read(mscm_regmap, MSCM_CPxCFG1_OFFSET, &cpxcfg1);
+
+	soc_type[0] = cpxcount ? '6' : '5'; /* Dual Core => VF6x0 */
+	soc_type[1] = cpxcfg1 ? '1' : '0'; /* L2 Cache => VFx10 */
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		goto out;
+
+	soc_dev_attr->machine = kasprintf(GFP_KERNEL, "Freescale Vybrid");
+	soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "%llx", soc_id);
+	soc_dev_attr->family = kasprintf(GFP_KERNEL, "Freescale Vybrid VF%s",
+								 soc_type);
+
+	rom_rev = ioremap(ROM_REVISION_REGISTER, SZ_1);
+	if (rom_rev)
+		soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%08x",
+						readl(rom_rev));
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		if (!rom_rev)
+			kfree(soc_dev_attr->revision);
+		kfree(soc_dev_attr->family);
+		kfree(soc_dev_attr->soc_id);
+		kfree(soc_dev_attr->machine);
+		kfree(soc_dev_attr);
+		goto out;
+	}
+
+	parent = soc_device_to_device(soc_dev);
+
+out:
+	of_platform_populate(NULL, of_default_bus_match_table, NULL, parent);
 	vf610_pm_init();
 }
 
-- 
2.4.0