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 <[email protected]> --- V4: * rebased on next-20121031 V3: * update the commit message V2: * no change --- arch/arm/mach-tegra/flowctrl.c | 47 ++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-tegra/flowctrl.h | 8 ++++++ 2 files changed, 55 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-tegra/flowctrl.c b/arch/arm/mach-tegra/flowctrl.c index ffaa286..a2250dd 100644 --- a/arch/arm/mach-tegra/flowctrl.c +++ b/arch/arm/mach-tegra/flowctrl.c @@ -21,6 +21,7 @@ #include <linux/init.h> #include <linux/kernel.h> #include <linux/io.h> +#include <linux/cpumask.h> #include "flowctrl.h" #include "iomap.h" @@ -50,6 +51,14 @@ static void flowctrl_update(u8 offset, u32 value) readl_relaxed(addr); } +u32 flowctrl_read_cpu_csr(unsigned int cpuid) +{ + u8 offset = flowctrl_offset_cpu_csr[cpuid]; + void __iomem *addr = IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + offset; + + return readl(addr); +} + void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value) { return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value); @@ -59,3 +68,41 @@ void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value) { return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value); } + +void flowctrl_cpu_suspend_enter(unsigned int cpuid) +{ + unsigned int reg; + 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 */ + 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); + + for (i = 0; i < num_possible_cpus(); i++) { + if (i == cpuid) + continue; + reg = flowctrl_read_cpu_csr(i); + reg |= FLOW_CTRL_CSR_EVENT_FLAG; + reg |= FLOW_CTRL_CSR_INTR_FLAG; + flowctrl_write_cpu_csr(i, reg); + } +} + +void flowctrl_cpu_suspend_exit(unsigned int cpuid) +{ + unsigned int reg; + + /* 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 */ + reg &= ~FLOW_CTRL_CSR_ENABLE; /* clear enable */ + reg |= FLOW_CTRL_CSR_INTR_FLAG; /* clear intr */ + reg |= FLOW_CTRL_CSR_EVENT_FLAG; /* clear event */ + flowctrl_write_cpu_csr(cpuid, reg); +} diff --git a/arch/arm/mach-tegra/flowctrl.h b/arch/arm/mach-tegra/flowctrl.h index 1942817..0798dec 100644 --- a/arch/arm/mach-tegra/flowctrl.h +++ b/arch/arm/mach-tegra/flowctrl.h @@ -34,9 +34,17 @@ #define FLOW_CTRL_HALT_CPU1_EVENTS 0x14 #define FLOW_CTRL_CPU1_CSR 0x18 +#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) + #ifndef __ASSEMBLY__ +u32 flowctrl_read_cpu_csr(unsigned int cpuid); void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value); void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value); + +void flowctrl_cpu_suspend_enter(unsigned int cpuid); +void flowctrl_cpu_suspend_exit(unsigned int cpuid); #endif #endif -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
