arm: zynq: Add support for system reset

Do system reset via slcr registers.

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

3 files changed, 34 insertions, 0 deletions

diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c
index cd3968c28904..f0a8533af1f9 100644
--- a/arch/arm/mach-zynq/common.c
+++ b/arch/arm/mach-zynq/common.c
@@ -92,6 +92,11 @@ static void __init xilinx_map_io(void)
         zynq_scu_map_io();
 }
 
+static void zynq_system_reset(char mode, const char *cmd)
+{
+        zynq_slcr_system_reset();
+}
+
 static const char *xilinx_dt_match[] = {
         "xlnx,zynq-zc702",
         "xlnx,zynq-7000",
@@ -104,4 +109,5 @@ MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
         .init_machine   = xilinx_init_machine,
         .init_time      = xilinx_zynq_timer_init,
         .dt_compat      = xilinx_dt_match,
+        .restart        = zynq_system_reset,
 MACHINE_END
diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h
index dd594e672ed4..d7ec3caaa1d7 100644
--- a/arch/arm/mach-zynq/common.h
+++ b/arch/arm/mach-zynq/common.h
@@ -18,6 +18,7 @@
 #define __MACH_ZYNQ_COMMON_H__
 
 extern int zynq_slcr_init(void);
+extern void zynq_slcr_system_reset(void);
 
 extern void __iomem *zynq_slcr_base;
 extern void __iomem *zynq_scu_base;
diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
index f9f33496cee9..d58c9964e883 100644
--- a/arch/arm/mach-zynq/slcr.c
+++ b/arch/arm/mach-zynq/slcr.c
@@ -32,9 +32,36 @@
 #define SLCR_UNLOCK_MAGIC               0xDF0D
 #define SLCR_UNLOCK                     0x8   /* SCLR unlock register */
 
+#define SLCR_PS_RST_CTRL_OFFSET         0x200 /* PS Software Reset Control */
+#define SLCR_REBOOT_STATUS              0x258 /* PS Reboot Status */
+
 void __iomem *zynq_slcr_base;
 
 /**
+ * zynq_slcr_system_reset - Reset the entire system.
+ */
+void zynq_slcr_system_reset(void)
+{
+        u32 reboot;
+
+        /*
+         * Unlock the SLCR then reset the system.
+         * Note that this seems to require raw i/o
+         * functions or there's a lockup?
+         */
+        writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + 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);
+        writel(reboot & 0xF0FFFFFF, zynq_slcr_base + SLCR_REBOOT_STATUS);
+        writel(1, zynq_slcr_base + SLCR_PS_RST_CTRL_OFFSET);
+}
+
+/**
  * zynq_slcr_init
  * Returns 0 on success, negative errno otherwise.
  *