ARM: tegra30: flowctrl: add cpu_suspend_exter/exit function
The flow controller can help CPU to go into suspend mode (powered-down
state). When CPU go into powered-down state, it needs some careful
settings before getting into and after leaving. The enter and exit
functions do that by configuring appropriate mode for flow controller.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/mach-tegra/flowctrl.c b/arch/arm/mach-tegra/flowctrl.c
index ffaa286..a2250dd 100644
--- a/arch/arm/mach-tegra/flowctrl.c
+++ b/arch/arm/mach-tegra/flowctrl.c
@@ -21,6 +21,7 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
+#include <linux/cpumask.h>
#include "flowctrl.h"
#include "iomap.h"
@@ -50,6 +51,14 @@
readl_relaxed(addr);
}
+u32 flowctrl_read_cpu_csr(unsigned int cpuid)
+{
+ u8 offset = flowctrl_offset_cpu_csr[cpuid];
+ void __iomem *addr = IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + offset;
+
+ return readl(addr);
+}
+
void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
{
return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
@@ -59,3 +68,41 @@
{
return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
}
+
+void flowctrl_cpu_suspend_enter(unsigned int cpuid)
+{
+ unsigned int reg;
+ int i;
+
+ reg = flowctrl_read_cpu_csr(cpuid);
+ reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP; /* clear wfe bitmap */
+ reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP; /* clear wfi bitmap */
+ reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr flag */
+ reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event flag */
+ reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid; /* pwr gating on wfi */
+ reg |= FLOW_CTRL_CSR_ENABLE; /* pwr gating */
+ flowctrl_write_cpu_csr(cpuid, reg);
+
+ for (i = 0; i < num_possible_cpus(); i++) {
+ if (i == cpuid)
+ continue;
+ reg = flowctrl_read_cpu_csr(i);
+ reg |= FLOW_CTRL_CSR_EVENT_FLAG;
+ reg |= FLOW_CTRL_CSR_INTR_FLAG;
+ flowctrl_write_cpu_csr(i, reg);
+ }
+}
+
+void flowctrl_cpu_suspend_exit(unsigned int cpuid)
+{
+ unsigned int reg;
+
+ /* Disable powergating via flow controller for CPU0 */
+ reg = flowctrl_read_cpu_csr(cpuid);
+ reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP; /* clear wfe bitmap */
+ reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP; /* clear wfi bitmap */
+ reg &= ~FLOW_CTRL_CSR_ENABLE; /* clear enable */
+ reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr */
+ reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event */
+ flowctrl_write_cpu_csr(cpuid, reg);
+}