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>

diff --git a/arch/arm/mach-imx/clock-imx6q.c b/arch/arm/mach-imx/clock-imx6q.c
index 039a7ab..9273c2a 100644 (file)
--- a/arch/arm/mach-imx/clock-imx6q.c
+++ b/arch/arm/mach-imx/clock-imx6q.c
@@ -1931,14 +1931,12 @@ int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode)
                val |= 0x1 << BP_CLPCR_LPM;
                val &= ~BM_CLPCR_VSTBY;
                val &= ~BM_CLPCR_SBYOS;
-               val |= BM_CLPCR_BYP_MMDC_CH1_LPM_HS;
                break;
        case STOP_POWER_OFF:
                val |= 0x2 << BP_CLPCR_LPM;
                val |= 0x3 << BP_CLPCR_STBY_COUNT;
                val |= BM_CLPCR_VSTBY;
                val |= BM_CLPCR_SBYOS;
-               val |= BM_CLPCR_BYP_MMDC_CH1_LPM_HS;
                break;
        default:
                return -EINVAL;

diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 7c6f9ec..05b49bb 100644 (file)
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -10,10 +10,13 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
+#include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <asm/hardware/cache-l2x0.h>
@@ -23,6 +26,36 @@
 #include <mach/common.h>
 #include <mach/hardware.h>
 
+void imx6q_restart(char mode, const char *cmd)
+{
+       struct device_node *np;
+       void __iomem *wdog_base;
+
+       np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-wdt");
+       wdog_base = of_iomap(np, 0);
+       if (!wdog_base)
+               goto soft;
+
+       imx_src_prepare_restart();
+
+       /* enable wdog */
+       writew_relaxed(1 << 2, wdog_base);
+       /* write twice to ensure the request will not get ignored */
+       writew_relaxed(1 << 2, wdog_base);
+
+       /* wait for reset to assert ... */
+       mdelay(500);
+
+       pr_err("Watchdog reset failed to assert reset\n");
+
+       /* delay to allow the serial port to show the message */
+       mdelay(50);
+
+soft:
+       /* we'll take a jump through zero as a poor second */
+       soft_restart(0);
+}
+
 static void __init imx6q_init_machine(void)
 {
        of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
@@ -83,5 +116,5 @@ DT_MACHINE_START(IMX6Q, "Freescale i.MX6 Quad (Device Tree)")
        .timer          = &imx6q_timer,
        .init_machine   = imx6q_init_machine,
        .dt_compat      = imx6q_dt_compat,
-       .restart        = mxc_restart,
+       .restart        = imx6q_restart,
 MACHINE_END

diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c
index a8e3368..4bde04f 100644 (file)
--- 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);
 }

diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
index e519446..18e5065 100644 (file)
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -122,6 +122,7 @@ static inline void imx_smp_prepare(void) {}
 extern void imx_enable_cpu(int cpu, bool enable);
 extern void imx_set_cpu_jump(int cpu, void *jump_addr);
 extern void imx_src_init(void);
+extern void imx_src_prepare_restart(void);
 extern void imx_gpc_init(void);
 extern void imx_gpc_pre_suspend(void);
 extern void imx_gpc_post_resume(void);