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/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index d69f99f..36ad689 100644
--- 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 <linux/phy.h>
@@ -41,6 +44,36 @@
return 0;
}
+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)
{
if (of_machine_is_compatible("fsl,imx6q-sabrelite"))
@@ -108,4 +141,5 @@
.timer = &imx6q_timer,
.init_machine = imx6q_init_machine,
.dt_compat = imx6q_dt_compat,
+ .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
--- 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 @@
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 08dda1f..7365b27 100644
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -123,6 +123,7 @@
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 bool imx_gpc_wake_irq_pending(void);
extern void imx_gpc_pre_suspend(void);