ARM: 7198/1: arm/imx6: add restart support for imx6q

The restart support was missed from the initial imx6q submission.
The mxc_restart() does not work for imx6q.  Instead, this patch adds
the restart for imx6q.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c
index a8e33681b732..4bde04f99e38 100644
--- a/arch/arm/mach-imx/src.c
+++ b/arch/arm/mach-imx/src.c
@@ -19,6 +19,7 @@
 
 #define SRC_SCR                         0x000
 #define SRC_GPR1                        0x020
+#define BP_SRC_SCR_WARM_RESET_ENABLE    0
 #define BP_SRC_SCR_CORE1_RST            14
 #define BP_SRC_SCR_CORE1_ENABLE         22
 
@@ -46,11 +47,33 @@ void imx_set_cpu_jump(int cpu, void *jump_addr)
                        src_base + SRC_GPR1 + cpu * 8);
 }
 
+void imx_src_prepare_restart(void)
+{
+        u32 val;
+
+        /* clear enable bits of secondary cores */
+        val = readl_relaxed(src_base + SRC_SCR);
+        val &= ~(0x7 << BP_SRC_SCR_CORE1_ENABLE);
+        writel_relaxed(val, src_base + SRC_SCR);
+
+        /* clear persistent entry register of primary core */
+        writel_relaxed(0, src_base + SRC_GPR1);
+}
+
 void __init imx_src_init(void)
 {
         struct device_node *np;
+        u32 val;
 
         np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-src");
         src_base = of_iomap(np, 0);
         WARN_ON(!src_base);
+
+        /*
+         * force warm reset sources to generate cold reset
+         * for a more reliable restart
+         */
+        val = readl_relaxed(src_base + SRC_SCR);
+        val &= ~(1 << BP_SRC_SCR_WARM_RESET_ENABLE);
+        writel_relaxed(val, src_base + SRC_SCR);
 }