ARM: tegra20: flowctrl: add support for cpu_suspend_enter/exit

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>

2 files changed, 37 insertions, 5 deletions

diff --git a/arch/arm/mach-tegra/flowctrl.c b/arch/arm/mach-tegra/flowctrl.c
index 5393eb2cae21..b477ef310dcd 100644
--- a/arch/arm/mach-tegra/flowctrl.c
+++ b/arch/arm/mach-tegra/flowctrl.c
@@ -25,6 +25,7 @@
 
 #include "flowctrl.h"
 #include "iomap.h"
+#include "fuse.h"
 
 static u8 flowctrl_offset_halt_cpu[] = {
         FLOW_CTRL_HALT_CPU0_EVENTS,
@@ -75,11 +76,26 @@ void flowctrl_cpu_suspend_enter(unsigned int cpuid)
         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 */
+        switch (tegra_chip_id) {
+        case TEGRA20:
+                /* clear wfe bitmap */
+                reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
+                /* clear wfi bitmap */
+                reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
+                /* pwr gating on wfe */
+                reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
+                break;
+        case TEGRA30:
+                /* clear wfe bitmap */
+                reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
+                /* clear wfi bitmap */
+                reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
+                /* pwr gating on wfi */
+                reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
+                break;
+        }
         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);
 
@@ -99,8 +115,20 @@ void flowctrl_cpu_suspend_exit(unsigned int cpuid)
 
         /* 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 */
+        switch (tegra_chip_id) {
+        case TEGRA20:
+                /* clear wfe bitmap */
+                reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
+                /* clear wfi bitmap */
+                reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
+                break;
+        case TEGRA30:
+                /* clear wfe bitmap */
+                reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
+                /* clear wfi bitmap */
+                reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
+                break;
+        }
         reg &= ~FLOW_CTRL_CSR_ENABLE;                   /* clear enable */
         reg |= FLOW_CTRL_CSR_INTR_FLAG;                 /* clear intr */
         reg |= FLOW_CTRL_CSR_EVENT_FLAG;                /* clear event */
diff --git a/arch/arm/mach-tegra/flowctrl.h b/arch/arm/mach-tegra/flowctrl.h
index 0798dec1832d..67eab56699bd 100644
--- a/arch/arm/mach-tegra/flowctrl.h
+++ b/arch/arm/mach-tegra/flowctrl.h
@@ -34,6 +34,10 @@
 #define FLOW_CTRL_HALT_CPU1_EVENTS      0x14
 #define FLOW_CTRL_CPU1_CSR              0x18
 
+#define TEGRA20_FLOW_CTRL_CSR_WFE_CPU0          (1 << 4)
+#define TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP        (3 << 4)
+#define TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP        0
+
 #define TEGRA30_FLOW_CTRL_CSR_WFI_CPU0          (1 << 8)
 #define TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP        (0xF << 4)
 #define TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP        (0xF << 8)