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ARM: tegra30: flowctrl: add cpu_suspend_exter/exit function

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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 <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
This commit is contained in:
Joseph Lo 2012-10-31 17:41:20 +08:00 committed by Stephen Warren
parent a6e293eef2
commit 01459c69dd
2 changed files with 55 additions and 0 deletions
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47
arch/arm/mach-tegra/flowctrl.c
View File

@ -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);
}

8
arch/arm/mach-tegra/flowctrl.h
View File

@ -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