ARM: integrator: hook the AP into the SoC bus

This hooks the Integrator/AP into the SoC bus when booting from
device tree, by mapping the AP controller registers first,
then registering the SoC device, and then populating the device
tree with the SoC device as parent.

Introduce some helpers in the core to provide sysfs files
detailing the use of the SoC ID which will later be reused by
the Integrator/CP patch for the same bus grouping.

Cc: Lee Jones <lee.jones@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 55 insertions, 2 deletions

diff --git a/arch/arm/mach-integrator/integrator_ap.c b/arch/arm/mach-integrator/integrator_ap.c
index e6617c134faf..7d84080f9aa3 100644
--- a/arch/arm/mach-integrator/integrator_ap.c
+++ b/arch/arm/mach-integrator/integrator_ap.c
@@ -37,6 +37,8 @@
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>
+#include <linux/stat.h>
+#include <linux/sys_soc.h>
 #include <video/vga.h>
 
 #include <mach/hardware.h>
@@ -462,13 +464,64 @@ static struct of_dev_auxdata ap_auxdata_lookup[] __initdata = {
 	{ /* sentinel */ },
 };
 
+/* Base address to the AP system controller */
+static void __iomem *ap_syscon_base;
+
 static void __init ap_init_of(void)
 {
 	unsigned long sc_dec;
+	struct device_node *root;
+	struct device_node *syscon;
+	struct device *parent;
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+	u32 ap_sc_id;
+	int err;
 	int i;
 
-	of_platform_populate(NULL, of_default_bus_match_table,
-			ap_auxdata_lookup, NULL);
+	/* Here we create an SoC device for the root node */
+	root = of_find_node_by_path("/");
+	if (!root)
+		return;
+	syscon = of_find_node_by_path("/syscon");
+	if (!syscon)
+		return;
+
+	ap_syscon_base = of_iomap(syscon, 0);
+	if (!ap_syscon_base)
+		return;
+
+	ap_sc_id = readl(ap_syscon_base);
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return;
+
+	err = of_property_read_string(root, "compatible",
+				      &soc_dev_attr->soc_id);
+	if (err)
+		return;
+	err = of_property_read_string(root, "model", &soc_dev_attr->machine);
+	if (err)
+		return;
+	soc_dev_attr->family = "Integrator";
+	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%c",
+					   'A' + (ap_sc_id & 0x0f));
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR_OR_NULL(soc_dev)) {
+		kfree(soc_dev_attr->revision);
+		kfree(soc_dev_attr);
+		return;
+	}
+
+	parent = soc_device_to_device(soc_dev);
+
+	if (!IS_ERR_OR_NULL(parent))
+		integrator_init_sysfs(parent, ap_sc_id);
+
+	of_platform_populate(root, of_default_bus_match_table,
+			ap_auxdata_lookup, parent);
 
 	sc_dec = readl(VA_SC_BASE + INTEGRATOR_SC_DEC_OFFSET);
 	for (i = 0; i < 4; i++) {