diff options
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/tegra/clk-tegra20.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c index 077d5b9ffe22..5d41569883a7 100644 --- a/drivers/clk/tegra/clk-tegra20.c +++ b/drivers/clk/tegra/clk-tegra20.c @@ -21,6 +21,7 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/clk/tegra.h> +#include <linux/delay.h> #include "clk.h" @@ -104,6 +105,13 @@ #define SUPER_SCLK_DIVIDER 0x2c #define CLK_SYSTEM_RATE 0x30 +#define CCLK_BURST_POLICY_SHIFT 28 +#define CCLK_RUN_POLICY_SHIFT 4 +#define CCLK_IDLE_POLICY_SHIFT 0 +#define CCLK_IDLE_POLICY 1 +#define CCLK_RUN_POLICY 2 +#define CCLK_BURST_POLICY_PLLX 8 + #define CLK_SOURCE_I2S1 0x100 #define CLK_SOURCE_I2S2 0x104 #define CLK_SOURCE_SPDIF_OUT 0x108 @@ -169,6 +177,17 @@ #define CPU_CLOCK(cpu) (0x1 << (8 + cpu)) #define CPU_RESET(cpu) (0x1111ul << (cpu)) +#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 int periph_clk_enb_refcnt[CLK_OUT_ENB_NUM * 32]; static void __iomem *clk_base; @@ -1136,12 +1155,86 @@ static void tegra20_disable_cpu_clock(u32 cpu) 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(clk_base + + TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET); + + return !!(cpu_rst_status & 0x2); +} + +static void tegra20_cpu_clock_suspend(void) +{ + /* switch coresite to clk_m, save off original source */ + tegra20_cpu_clk_sctx.clk_csite_src = + readl(clk_base + CLK_SOURCE_CSITE); + writel(3<<30, clk_base + CLK_SOURCE_CSITE); + + tegra20_cpu_clk_sctx.cpu_burst = + readl(clk_base + CCLK_BURST_POLICY); + tegra20_cpu_clk_sctx.pllx_base = + readl(clk_base + PLLX_BASE); + tegra20_cpu_clk_sctx.pllx_misc = + readl(clk_base + PLLX_MISC); + tegra20_cpu_clk_sctx.cclk_divider = + readl(clk_base + SUPER_CCLK_DIVIDER); +} + +static void tegra20_cpu_clock_resume(void) +{ + unsigned int reg, policy; + + /* Is CPU complex already running on PLLX? */ + reg = readl(clk_base + CCLK_BURST_POLICY); + policy = (reg >> CCLK_BURST_POLICY_SHIFT) & 0xF; + + if (policy == CCLK_IDLE_POLICY) + reg = (reg >> CCLK_IDLE_POLICY_SHIFT) & 0xF; + else if (policy == CCLK_RUN_POLICY) + reg = (reg >> CCLK_RUN_POLICY_SHIFT) & 0xF; + else + BUG(); + + if (reg != CCLK_BURST_POLICY_PLLX) { + /* restore PLLX settings if CPU is on different PLL */ + writel(tegra20_cpu_clk_sctx.pllx_misc, + clk_base + PLLX_MISC); + writel(tegra20_cpu_clk_sctx.pllx_base, + clk_base + 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, + clk_base + SUPER_CCLK_DIVIDER); + writel(tegra20_cpu_clk_sctx.cpu_burst, + clk_base + CCLK_BURST_POLICY); + + writel(tegra20_cpu_clk_sctx.clk_csite_src, + clk_base + CLK_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 }; static __initdata struct tegra_clk_init_table init_table[] = { |