[PATCH 3/5] ARM: twd: Add context save restore support
From: Santosh Shilimkar <hidden>
Date: 2011-01-24 08:51:17
Also in:
linux-omap
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
In CPU low power state, local timer looses its register context. This patch adds context save restore hooks which can be used by platforms appropriately. Signed-off-by: Santosh Shilimkar <redacted> Cc: Russell King <redacted> --- arch/arm/include/asm/localtimer.h | 13 +++++++++++++ arch/arm/include/asm/smp_twd.h | 2 ++ arch/arm/kernel/smp_twd.c | 24 ++++++++++++++++++++++++ 3 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/localtimer.h b/arch/arm/include/asm/localtimer.h
index 6bc63ab..6753754 100644
--- a/arch/arm/include/asm/localtimer.h
+++ b/arch/arm/include/asm/localtimer.h@@ -31,6 +31,9 @@ asmlinkage void do_local_timer(struct pt_regs *); #define local_timer_ack() twd_timer_ack() +#define local_timer_save(cpu) twd_context_save(cpu); +#define local_timer_restore(cpu) twd_context_save(cpu); + #else /*
@@ -46,6 +49,16 @@ int local_timer_ack(void); */ void local_timer_setup(struct clock_event_device *); +/* + * Save local timer register context + */ +void local_timer_save(unsigned int cpu); + +/* + * Restore local timer register context + */ +void local_timer_restoree(unsigned int cpu); + #endif #endif
diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h
index fed9981..7828f29 100644
--- a/arch/arm/include/asm/smp_twd.h
+++ b/arch/arm/include/asm/smp_twd.h@@ -24,5 +24,7 @@ extern void __iomem *twd_base; int twd_timer_ack(void); void twd_timer_setup(struct clock_event_device *); +void twd_context_save(unsigned int cpu); +void twd_context_restore(unsigned int cpu); #endif
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index fd91566..f3098e4 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c@@ -24,6 +24,12 @@ /* set up by the platform code */ void __iomem *twd_base; +/* Timer context to be saved in low power modes */ +struct twd_registers { + unsigned long timer_ctrl; + unsigned long timer_load; +}; +static DEFINE_PER_CPU(struct twd_registers, twd_context); static unsigned long twd_timer_rate; static void twd_set_mode(enum clock_event_mode mode,
@@ -145,3 +151,21 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk) clockevents_register_device(clk); } + +/* Low power context save */ +void twd_context_save(unsigned int cpu) +{ + struct twd_registers *regs = &per_cpu(twd_context, cpu); + + regs->timer_ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL); + regs->timer_load = __raw_readl(twd_base + TWD_TIMER_LOAD); +} + +/* Low power context restore */ +void twd_context_restore(unsigned int cpu) +{ + struct twd_registers *regs = &per_cpu(twd_context, cpu); + + __raw_writel(regs->timer_load, twd_base + TWD_TIMER_LOAD); + __raw_writel(regs->timer_ctrl, twd_base + TWD_TIMER_CONTROL); +}
--
1.6.0.4