1 files changed, 89 insertions, 15 deletions

diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
index 1836d5a34606..a37d49a6e657 100644
--- a/arch/arm/mach-zynq/slcr.c
+++ b/arch/arm/mach-zynq/slcr.c
@@ -15,7 +15,9 @@
  */
 
 #include <linux/io.h>
+#include <linux/mfd/syscon.h>
 #include <linux/of_address.h>
+#include <linux/regmap.h>
 #include <linux/clk/zynq.h>
 #include "common.h"
 
@@ -29,7 +31,56 @@
 #define SLCR_A9_CPU_CLKSTOP             0x10
 #define SLCR_A9_CPU_RST                 0x1
 
-void __iomem *zynq_slcr_base;
+static void __iomem *zynq_slcr_base;
+static struct regmap *zynq_slcr_regmap;
+
+/**
+ * zynq_slcr_write - Write to a register in SLCR block
+ *
+ * @val:        Value to write to the register
+ * @offset:     Register offset in SLCR block
+ *
+ * Return:      a negative value on error, 0 on success
+ */
+static int zynq_slcr_write(u32 val, u32 offset)
+{
+        if (!zynq_slcr_regmap) {
+                writel(val, zynq_slcr_base + offset);
+                return 0;
+        }
+
+        return regmap_write(zynq_slcr_regmap, offset, val);
+}
+
+/**
+ * zynq_slcr_read - Read a register in SLCR block
+ *
+ * @val:        Pointer to value to be read from SLCR
+ * @offset:     Register offset in SLCR block
+ *
+ * Return:      a negative value on error, 0 on success
+ */
+static int zynq_slcr_read(u32 *val, u32 offset)
+{
+        if (zynq_slcr_regmap)
+                return regmap_read(zynq_slcr_regmap, offset, val);
+
+        *val = readl(zynq_slcr_base + offset);
+
+        return 0;
+}
+
+/**
+ * zynq_slcr_unlock - Unlock SLCR registers
+ *
+ * Return:      a negative value on error, 0 on success
+ */
+static inline int zynq_slcr_unlock(void)
+{
+        zynq_slcr_write(SLCR_UNLOCK_MAGIC, SLCR_UNLOCK_OFFSET);
+
+        return 0;
+}
 
 /**
  * zynq_slcr_system_reset - Reset the entire system.
@@ -43,16 +94,16 @@ void zynq_slcr_system_reset(void)
          * Note that this seems to require raw i/o
          * functions or there's a lockup?
          */
-        writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
+        zynq_slcr_unlock();
 
         /*
          * Clear 0x0F000000 bits of reboot status register to workaround
          * the FSBL not loading the bitstream after soft-reboot
          * This is a temporary solution until we know more.
          */
-        reboot = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
-        writel(reboot & 0xF0FFFFFF, zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
-        writel(1, zynq_slcr_base + SLCR_PS_RST_CTRL_OFFSET);
+        zynq_slcr_read(&reboot, SLCR_REBOOT_STATUS_OFFSET);
+        zynq_slcr_write(reboot & 0xF0FFFFFF, SLCR_REBOOT_STATUS_OFFSET);
+        zynq_slcr_write(1, SLCR_PS_RST_CTRL_OFFSET);
 }
 
 /**
@@ -61,11 +112,13 @@ void zynq_slcr_system_reset(void)
  */
 void zynq_slcr_cpu_start(int cpu)
 {
-        u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+        u32 reg;
+
+        zynq_slcr_read(&reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
         reg &= ~(SLCR_A9_CPU_RST << cpu);
-        writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+        zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
         reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu);
-        writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+        zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
 }
 
 /**
@@ -74,19 +127,40 @@ void zynq_slcr_cpu_start(int cpu)
  */
 void zynq_slcr_cpu_stop(int cpu)
 {
-        u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+        u32 reg;
+
+        zynq_slcr_read(&reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
         reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu;
-        writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+        zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
 }
 
 /**
- * zynq_slcr_init
- * Returns 0 on success, negative errno otherwise.
+ * zynq_slcr_init - Regular slcr driver init
+ *
+ * Return:      0 on success, negative errno otherwise.
  *
  * Called early during boot from platform code to remap SLCR area.
  */
 int __init zynq_slcr_init(void)
 {
+        zynq_slcr_regmap = syscon_regmap_lookup_by_compatible("xlnx,zynq-slcr");
+        if (IS_ERR(zynq_slcr_regmap)) {
+                pr_err("%s: failed to find zynq-slcr\n", __func__);
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+/**
+ * zynq_early_slcr_init - Early slcr init function
+ *
+ * Return:      0 on success, negative errno otherwise.
+ *
+ * Called very early during boot from platform code to unlock SLCR.
+ */
+int __init zynq_early_slcr_init(void)
+{
         struct device_node *np;
 
         np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr");
@@ -101,13 +175,13 @@ int __init zynq_slcr_init(void)
                 BUG();
         }
 
+        np->data = (__force void *)zynq_slcr_base;
+
         /* unlock the SLCR so that registers can be changed */
-        writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
+        zynq_slcr_unlock();
 
         pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
 
-        zynq_clock_init(zynq_slcr_base);
-
         of_node_put(np);
 
         return 0;