ARM: tegra: add LP1 suspend support for Tegra30

The LP1 suspend mode will power off the CPU, clock gated the PLLs and put
SDRAM to self-refresh mode. Any interrupt can wake up device from LP1. The
sequence when LP1 suspending:

* tunning off L1 data cache and the MMU
* storing some EMC registers, DPD (deep power down) status, clk source of
  mselect and SCLK burst policy
* putting SDRAM into self-refresh
* switching CPU to CLK_M (12MHz OSC)
* tunning off PLLM, PLLP, PLLA, PLLC and PLLX
* switching SCLK to CLK_S (32KHz OSC)
* shutting off the CPU rail

The sequence of LP1 resuming:

* re-enabling PLLM, PLLP, PLLA, PLLC and PLLX
* restoring the clk source of mselect and SCLK burst policy
* setting up CCLK burst policy to PLLX
* restoring DPD status and some EMC registers
* resuming SDRAM to normal mode
* jumping to the "tegra_resume" from PMC_SCRATCH41

Due to the SDRAM will be put into self-refresh mode, the low level
procedures of LP1 suspending and resuming should be copied to
TEGRA_IRAM_CODE_AREA (TEGRA_IRAM_BASE + SZ_4K) when suspending. Before
restoring the CPU context when resuming, the SDRAM needs to be switched
back to normal mode. And the PLLs need to be re-enabled, SCLK burst policy
be restored, CCLK burst policy be set in PLLX. Then jumping to
"tegra_resume" that was expected to be stored in PMC_SCRATCH41 to restore
CPU context and back to kernel.

Based on the work by: Scott Williams <scwilliams@nvidia.com>

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index 10689924a6a7..7739d5586cb7 100644
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -209,6 +209,15 @@ static int tegra_sleep_core(unsigned long v2p)
  */
 static bool tegra_lp1_iram_hook(void)
 {
+        switch (tegra_chip_id) {
+        case TEGRA30:
+                if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))
+                        tegra30_lp1_iram_hook();
+                break;
+        default:
+                break;
+        }
+
         if (!tegra_lp1_iram.start_addr || !tegra_lp1_iram.end_addr)
                 return false;
 
@@ -222,6 +231,15 @@ static bool tegra_lp1_iram_hook(void)
 
 static bool tegra_sleep_core_init(void)
 {
+        switch (tegra_chip_id) {
+        case TEGRA30:
+                if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))
+                        tegra30_sleep_core_init();
+                break;
+        default:
+                break;
+        }
+
         if (!tegra_sleep_core_finish)
                 return false;