ARM: zynq: Add support for SOC_BUS

Provide information through SOC_BUS to user space.
Silicon revision is provided through devcfg device.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

1 files changed, 70 insertions, 1 deletions

diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c
index 6fcc584c1a11..edbd9d83f407 100644
--- a/arch/arm/mach-zynq/common.c
+++ b/arch/arm/mach-zynq/common.c
@@ -29,6 +29,8 @@
 #include <linux/memblock.h>
 #include <linux/irqchip.h>
 #include <linux/irqchip/arm-gic.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -37,10 +39,15 @@
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/smp_scu.h>
+#include <asm/system_info.h>
 #include <asm/hardware/cache-l2x0.h>
 
 #include "common.h"
 
+#define ZYNQ_DEVCFG_MCTRL               0x80
+#define ZYNQ_DEVCFG_PS_VERSION_SHIFT    28
+#define ZYNQ_DEVCFG_PS_VERSION_MASK     0xF
+
 void __iomem *zynq_scu_base;
 
 /**
@@ -60,19 +67,81 @@ static struct platform_device zynq_cpuidle_device = {
 };
 
 /**
+ * zynq_get_revision - Get Zynq silicon revision
+ *
+ * Return: Silicon version or -1 otherwise
+ */
+static int __init zynq_get_revision(void)
+{
+        struct device_node *np;
+        void __iomem *zynq_devcfg_base;
+        u32 revision;
+
+        np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-devcfg-1.0");
+        if (!np) {
+                pr_err("%s: no devcfg node found\n", __func__);
+                return -1;
+        }
+
+        zynq_devcfg_base = of_iomap(np, 0);
+        if (!zynq_devcfg_base) {
+                pr_err("%s: Unable to map I/O memory\n", __func__);
+                return -1;
+        }
+
+        revision = readl(zynq_devcfg_base + ZYNQ_DEVCFG_MCTRL);
+        revision >>= ZYNQ_DEVCFG_PS_VERSION_SHIFT;
+        revision &= ZYNQ_DEVCFG_PS_VERSION_MASK;
+
+        iounmap(zynq_devcfg_base);
+
+        return revision;
+}
+
+/**
  * zynq_init_machine - System specific initialization, intended to be
  *                     called from board specific initialization.
  */
 static void __init zynq_init_machine(void)
 {
         struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
+        struct soc_device_attribute *soc_dev_attr;
+        struct soc_device *soc_dev;
+        struct device *parent = NULL;
 
         /*
          * 64KB way size, 8-way associativity, parity disabled
          */
         l2x0_of_init(0x02060000, 0xF0F0FFFF);
 
-        of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+        soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+        if (!soc_dev_attr)
+                goto out;
+
+        system_rev = zynq_get_revision();
+
+        soc_dev_attr->family = kasprintf(GFP_KERNEL, "Xilinx Zynq");
+        soc_dev_attr->revision = kasprintf(GFP_KERNEL, "0x%x", system_rev);
+        soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "0x%x",
+                                         zynq_slcr_get_device_id());
+
+        soc_dev = soc_device_register(soc_dev_attr);
+        if (IS_ERR(soc_dev)) {
+                kfree(soc_dev_attr->family);
+                kfree(soc_dev_attr->revision);
+                kfree(soc_dev_attr->soc_id);
+                kfree(soc_dev_attr);
+                goto out;
+        }
+
+        parent = soc_device_to_device(soc_dev);
+
+out:
+        /*
+         * Finished with the static registrations now; fill in the missing
+         * devices
+         */
+        of_platform_populate(NULL, of_default_bus_match_table, NULL, parent);
 
         platform_device_register(&zynq_cpuidle_device);
         platform_device_register_full(&devinfo);