@@ -32,6 +32,9 @@
#include "pm.h"
#include "sleep.h"
+#include "iomap.h"
+#include "tegra_cpu_car.h"
+#include "flowctrl.h"
#ifdef CONFIG_PM_SLEEP
static int tegra20_idle_lp2(struct cpuidle_device *dev,
@@ -68,6 +71,114 @@ static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
#ifdef CONFIG_PM_SLEEP
#ifdef CONFIG_SMP
+static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);
+
+static int tegra20_reset_sleeping_cpu(int cpu)
+{
+ int ret = 0;
+
+ BUG_ON(cpu == 0);
+ BUG_ON(cpu == smp_processor_id());
+ tegra_pen_lock();
+
+ if (readl(pmc + PMC_SCRATCH41) == CPU_RESETTABLE)
+ tegra20_cpu_shutdown(cpu);
+ else
+ ret = -EINVAL;
+
+ tegra_pen_unlock();
+
+ return ret;
+}
+
+static void tegra20_wake_reset_cpu(int cpu)
+{
+ BUG_ON(cpu == 0);
+ BUG_ON(cpu == smp_processor_id());
+
+ tegra_pen_lock();
+
+ tegra20_cpu_clear_resettable();
+
+ /* enable cpu clock on cpu */
+ tegra_enable_cpu_clock(cpu);
+
+ /* take the CPU out of reset */
+ tegra_cpu_out_of_reset(cpu);
+
+ /* unhalt the cpu */
+ flowctrl_write_cpu_halt(cpu, 0);
+
+ tegra_pen_unlock();
+}
+
+static int tegra20_reset_other_cpus(int cpu)
+{
+ int i;
+ int ret = 0;
+
+ BUG_ON(cpu != 0);
+
+ for_each_online_cpu(i) {
+ if (i != cpu) {
+ if (tegra20_reset_sleeping_cpu(i)) {
+ ret = -EBUSY;
+ break;
+ }
+ }
+ }
+
+ if (ret) {
+ for_each_online_cpu(i) {
+ if (i != cpu)
+ tegra20_wake_reset_cpu(i);
+ }
+ return ret;
+ }
+
+ return 0;
+}
+#else
+static inline void tegra20_wake_reset_cpu(int cpu)
+{
+}
+
+static inline int tegra20_reset_other_cpus(int cpu)
+{
+ return 0;
+}
+#endif
+
+static bool tegra20_cpu_cluster_power_down(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ int i;
+ struct cpuidle_state *state = &drv->states[index];
+ u32 cpu_on_time = state->exit_latency;
+ u32 cpu_off_time = state->target_residency - state->exit_latency;
+
+ while (tegra20_cpu_is_resettable_soon())
+ cpu_relax();
+
+ if (tegra20_reset_other_cpus(dev->cpu) || !tegra_cpu_rail_off_ready())
+ return false;
+
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
+
+ tegra_idle_lp2_last(cpu_on_time, cpu_off_time);
+
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
+
+ for_each_online_cpu(i) {
+ if (i != dev->cpu)
+ tegra20_wake_reset_cpu(i);
+ }
+
+ return true;
+}
+
+#ifdef CONFIG_SMP
static bool tegra20_idle_enter_lp2_cpu_1(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
@@ -99,16 +210,22 @@ static int __cpuinit tegra20_idle_lp2(struct cpuidle_device *dev,
{
u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
bool entered_lp2 = false;
+ bool last_cpu;
local_fiq_disable();
- tegra_set_cpu_in_lp2(cpu);
+ last_cpu = tegra_set_cpu_in_lp2(cpu);
cpu_pm_enter();
- if (cpu == 0)
- cpu_do_idle();
- else
+ if (cpu == 0) {
+ if (last_cpu)
+ entered_lp2 = tegra20_cpu_cluster_power_down(dev, drv,
+ index);
+ else
+ cpu_do_idle();
+ } else {
entered_lp2 = tegra20_idle_enter_lp2_cpu_1(dev, drv, index);
+ }
cpu_pm_exit();
tegra_clear_cpu_in_lp2(cpu);
@@ -128,6 +245,10 @@ int __init tegra20_cpuidle_init(void)
struct cpuidle_device *dev;
struct cpuidle_driver *drv = &tegra_idle_driver;
+#ifdef CONFIG_PM_SLEEP
+ tegra_tear_down_cpu = tegra20_tear_down_cpu;
+#endif
+
ret = cpuidle_register_driver(&tegra_idle_driver);
if (ret) {
pr_err("CPUidle driver registration failed\n");
@@ -60,6 +60,9 @@ ENDPROC(tegra20_hotplug_shutdown)
ENTRY(tegra20_cpu_shutdown)
cmp r0, #0
moveq pc, lr @ must not be called for CPU 0
+ mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ mov r12, #CPU_RESETTABLE
+ str r12, [r1]
cpu_to_halt_reg r1, r0
ldr r3, =TEGRA_FLOW_CTRL_VIRT
@@ -163,6 +166,21 @@ ENTRY(tegra20_cpu_set_resettable_soon)
ENDPROC(tegra20_cpu_set_resettable_soon)
/*
+ * tegra20_cpu_is_resettable_soon(void)
+ *
+ * Returns true if the "resettable soon" flag in PMC_SCRATCH41 has been
+ * set because it is expected that the secondary CPU will be idle soon.
+ */
+ENTRY(tegra20_cpu_is_resettable_soon)
+ mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
+ ldr r12, [r1]
+ cmp r12, #CPU_RESETTABLE_SOON
+ moveq r0, #1
+ movne r0, #0
+ mov pc, lr
+ENDPROC(tegra20_cpu_is_resettable_soon)
+
+/*
* tegra20_sleep_cpu_secondary_finish(unsigned long v2p)
*
* Enters WFI on secondary CPU by exiting coherency.
@@ -222,4 +240,39 @@ ENTRY(tegra20_sleep_cpu_secondary_finish)
mov sp, r2 @ sp is stored in r2 by __cpu_suspend
ldmfd sp!, {r4 - r11, pc}
ENDPROC(tegra20_sleep_cpu_secondary_finish)
+
+/*
+ * tegra20_tear_down_cpu
+ *
+ * Switches the CPU cluster to PLL-P and enters sleep.
+ */
+ENTRY(tegra20_tear_down_cpu)
+ bl tegra_cpu_pllp
+ b tegra20_enter_sleep
+ENDPROC(tegra20_tear_down_cpu)
+
+/*
+ * tegra20_enter_sleep
+ *
+ * uses flow controller to enter sleep state
+ * executes from IRAM with SDRAM in selfrefresh when target state is LP0 or LP1
+ * executes from SDRAM with target state is LP2
+ */
+tegra20_enter_sleep:
+ mov32 r6, TEGRA_FLOW_CTRL_BASE
+
+ mov r0, #FLOW_CTRL_WAIT_FOR_INTERRUPT
+ orr r0, r0, #FLOW_CTRL_HALT_CPU_IRQ | FLOW_CTRL_HALT_CPU_FIQ
+ cpu_id r1
+ cpu_to_halt_reg r1, r1
+ str r0, [r6, r1]
+ dsb
+ ldr r0, [r6, r1] /* memory barrier */
+
+halted:
+ dsb
+ wfe /* CPU should be power gated here */
+ isb
+ b halted
+
#endif
@@ -34,6 +34,9 @@
#include "flowctrl.h"
#include "sleep.h"
+#define CLK_RESET_CCLK_BURST 0x20
+#define CLK_RESET_CCLK_DIVIDER 0x24
+
#ifdef CONFIG_PM_SLEEP
/*
* tegra_disable_clean_inv_dcache
@@ -108,4 +111,20 @@ ENTRY(tegra_shut_off_mmu)
mov pc, r0
ENDPROC(tegra_shut_off_mmu)
.popsection
+
+/*
+ * tegra_cpu_pllp
+ *
+ * In LP2 the normal cpu clock pllx will be turned off. Switch the CPU to pllp
+ */
+ENTRY(tegra_cpu_pllp)
+ /* in LP2 idle (SDRAM active), set the CPU burst policy to PLLP */
+ mov32 r5, TEGRA_CLK_RESET_BASE
+ mov r0, #(2 << 28) @ burst policy = run mode
+ orr r0, r0, #(4 << 4) @ use PLLP in run mode burst
+ str r0, [r5, #CLK_RESET_CCLK_BURST]
+ mov r0, #0
+ str r0, [r5, #CLK_RESET_CCLK_DIVIDER]
+ mov pc, lr
+ENDPROC(tegra_cpu_pllp)
#endif
@@ -130,6 +130,8 @@ static inline void tegra20_hotplug_init(void) {}
static inline void tegra30_hotplug_init(void) {}
#endif
+void tegra20_cpu_shutdown(int cpu);
+int tegra20_cpu_is_resettable_soon(void);
void tegra20_cpu_clear_resettable(void);
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
void tegra20_cpu_set_resettable_soon(void);
@@ -138,6 +140,7 @@ static inline void tegra20_cpu_set_resettable_soon(void) {}
#endif
int tegra20_sleep_cpu_secondary_finish(unsigned long);
+void tegra20_tear_down_cpu(void);
int tegra30_sleep_cpu_secondary_finish(unsigned long);
void tegra30_tear_down_cpu(void);
The powered-down state of Tegra20 requires power gating both CPU cores. When the secondary CPU requests to enter powered-down state, it saves its own contexts and then enters WFI for waiting CPU0 in the same state. When the CPU0 requests powered-down state, it attempts to put the secondary CPU into reset to prevent it from waking up. Then power down both CPUs together and power off the cpu rail. Be aware of that, you may see the legacy power state "LP2" in the code which is exactly the same meaning of "CPU power down". Based on the work by: Colin Cross <ccross@android.com> Gary King <gking@nvidia.com> Signed-off-by: Joseph Lo <josephl@nvidia.com> --- arch/arm/mach-tegra/cpuidle-tegra20.c | 129 ++++++++++++++++++++++++++++++++- arch/arm/mach-tegra/sleep-tegra20.S | 53 ++++++++++++++ arch/arm/mach-tegra/sleep.S | 19 +++++ arch/arm/mach-tegra/sleep.h | 3 + 4 files changed, 200 insertions(+), 4 deletions(-)