Add suspend, resume and rail_off_ready API into tegra_cpu_car_ops. These
functions were used for CPU powered-down state maintenance.

Signed-off-by: Joseph Lo <[email protected]>
---
 arch/arm/mach-tegra/tegra20_clocks.c |  102 ++++++++++++++++++++++++++++++++++
 1 files changed, 102 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-tegra/tegra20_clocks.c 
b/arch/arm/mach-tegra/tegra20_clocks.c
index 4eb6bc8..05968d7 100644
--- a/arch/arm/mach-tegra/tegra20_clocks.c
+++ b/arch/arm/mach-tegra/tegra20_clocks.c
@@ -159,6 +159,31 @@
 #define CPU_CLOCK(cpu) (0x1 << (8 + cpu))
 #define CPU_RESET(cpu) (0x1111ul << (cpu))
 
+#define CLK_RESET_CCLK_BURST   0x20
+#define CLK_RESET_CCLK_DIVIDER  0x24
+#define CLK_RESET_PLLX_BASE    0xe0
+#define CLK_RESET_PLLX_MISC    0xe4
+
+#define CLK_RESET_SOURCE_CSITE 0x1d4
+
+#define CLK_RESET_CCLK_BURST_POLICY_SHIFT      28
+#define CLK_RESET_CCLK_RUN_POLICY_SHIFT                4
+#define CLK_RESET_CCLK_IDLE_POLICY_SHIFT       0
+#define CLK_RESET_CCLK_IDLE_POLICY             1
+#define CLK_RESET_CCLK_RUN_POLICY              2
+#define CLK_RESET_CCLK_BURST_POLICY_PLLX       8
+
+#ifdef CONFIG_PM_SLEEP
+static struct cpu_clk_suspend_context {
+       u32 pllx_misc;
+       u32 pllx_base;
+
+       u32 cpu_burst;
+       u32 clk_csite_src;
+       u32 cclk_divider;
+} tegra20_cpu_clk_sctx;
+#endif
+
 static void __iomem *reg_clk_base = IO_ADDRESS(TEGRA_CLK_RESET_BASE);
 static void __iomem *reg_pmc_base = IO_ADDRESS(TEGRA_PMC_BASE);
 
@@ -1609,12 +1634,89 @@ static void tegra20_disable_cpu_clock(u32 cpu)
               reg_clk_base + TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static bool tegra20_cpu_rail_off_ready(void)
+{
+       unsigned int cpu_rst_status;
+
+       cpu_rst_status = readl(reg_clk_base +
+                              TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET);
+
+       if ((cpu_rst_status & 0x2) != 0x2)
+               return false;
+
+       return true;
+}
+
+static void tegra20_cpu_clock_suspend(void)
+{
+       /* switch coresite to clk_m, save off original source */
+       tegra20_cpu_clk_sctx.clk_csite_src =
+                               readl(reg_clk_base + CLK_RESET_SOURCE_CSITE);
+       writel(3<<30, reg_clk_base + CLK_RESET_SOURCE_CSITE);
+
+       tegra20_cpu_clk_sctx.cpu_burst =
+                               readl(reg_clk_base + CLK_RESET_CCLK_BURST);
+       tegra20_cpu_clk_sctx.pllx_base =
+                               readl(reg_clk_base + CLK_RESET_PLLX_BASE);
+       tegra20_cpu_clk_sctx.pllx_misc =
+                               readl(reg_clk_base + CLK_RESET_PLLX_MISC);
+       tegra20_cpu_clk_sctx.cclk_divider =
+                               readl(reg_clk_base + CLK_RESET_CCLK_DIVIDER);
+}
+
+static void tegra20_cpu_clock_resume(void)
+{
+       unsigned int reg, policy;
+
+       /* Is CPU complex already running on PLLX? */
+       reg = readl(reg_clk_base + CLK_RESET_CCLK_BURST);
+       policy = (reg >> CLK_RESET_CCLK_BURST_POLICY_SHIFT) & 0xF;
+
+       if (policy == CLK_RESET_CCLK_IDLE_POLICY)
+               reg = (reg >> CLK_RESET_CCLK_IDLE_POLICY_SHIFT) & 0xF;
+       else if (policy == CLK_RESET_CCLK_RUN_POLICY)
+               reg = (reg >> CLK_RESET_CCLK_RUN_POLICY_SHIFT) & 0xF;
+       else
+               BUG();
+
+       if (reg != CLK_RESET_CCLK_BURST_POLICY_PLLX) {
+               /* restore PLLX settings if CPU is on different PLL */
+               writel(tegra20_cpu_clk_sctx.pllx_misc,
+                                       reg_clk_base + CLK_RESET_PLLX_MISC);
+               writel(tegra20_cpu_clk_sctx.pllx_base,
+                                       reg_clk_base + CLK_RESET_PLLX_BASE);
+
+               /* wait for PLL stabilization if PLLX was enabled */
+               if (tegra20_cpu_clk_sctx.pllx_base & (1 << 30))
+                       udelay(300);
+       }
+
+       /*
+        * Restore original burst policy setting for calls resulting from CPU
+        * LP2 in idle or system suspend.
+        */
+       writel(tegra20_cpu_clk_sctx.cclk_divider,
+                                       reg_clk_base + CLK_RESET_CCLK_DIVIDER);
+       writel(tegra20_cpu_clk_sctx.cpu_burst,
+                                       reg_clk_base + CLK_RESET_CCLK_BURST);
+
+       writel(tegra20_cpu_clk_sctx.clk_csite_src,
+                                       reg_clk_base + CLK_RESET_SOURCE_CSITE);
+}
+#endif
+
 static struct tegra_cpu_car_ops tegra20_cpu_car_ops = {
        .wait_for_reset = tegra20_wait_cpu_in_reset,
        .put_in_reset   = tegra20_put_cpu_in_reset,
        .out_of_reset   = tegra20_cpu_out_of_reset,
        .enable_clock   = tegra20_enable_cpu_clock,
        .disable_clock  = tegra20_disable_cpu_clock,
+#ifdef CONFIG_PM_SLEEP
+       .rail_off_ready = tegra20_cpu_rail_off_ready,
+       .suspend        = tegra20_cpu_clock_suspend,
+       .resume         = tegra20_cpu_clock_resume,
+#endif
 };
 
 void __init tegra20_cpu_car_ops_init(void)
-- 
1.7.0.4

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