ARM: OMAP: dmtimer: low-power mode support

Clock is enabled only when timer is started and disabled when the the timer
is stopped. Therefore before accessing registers in functions clock is enabled
and then disabled back at the end of access. Context save is done dynamically
whenever the registers are modified. Context restore is called when context is
lost.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[tony@atomide.com: updated to use revision instead of tidr]
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h
index 29764c34f57..9519d87179e 100644
--- a/arch/arm/plat-omap/include/plat/dmtimer.h
+++ b/arch/arm/plat-omap/include/plat/dmtimer.h
@@ -73,11 +73,38 @@ struct omap_timer_capability_dev_attr {
 struct omap_dm_timer;
 struct clk;
 
+struct timer_regs {
+        u32 tidr;
+        u32 tiocp_cfg;
+        u32 tistat;
+        u32 tisr;
+        u32 tier;
+        u32 twer;
+        u32 tclr;
+        u32 tcrr;
+        u32 tldr;
+        u32 ttrg;
+        u32 twps;
+        u32 tmar;
+        u32 tcar1;
+        u32 tsicr;
+        u32 tcar2;
+        u32 tpir;
+        u32 tnir;
+        u32 tcvr;
+        u32 tocr;
+        u32 towr;
+};
+
 struct dmtimer_platform_data {
         int (*set_timer_src)(struct platform_device *pdev, int source);
         int timer_ip_version;
         u32 needs_manual_reset:1;
         bool reserved;
+
+        bool loses_context;
+
+        u32 (*get_context_loss_count)(struct device *dev);
 };
 
 struct omap_dm_timer *omap_dm_timer_request(void);
@@ -245,8 +272,14 @@ struct omap_dm_timer {
         unsigned long rate;
         unsigned reserved:1;
         unsigned posted:1;
+        struct timer_regs context;
+        bool loses_context;
+        int ctx_loss_count;
+        int revision;
         struct platform_device *pdev;
         struct list_head node;
+
+        u32 (*get_context_loss_count)(struct device *dev);
 };
 
 int omap_dm_timer_prepare(struct omap_dm_timer *timer);
@@ -278,6 +311,7 @@ static inline void __omap_dm_timer_init_regs(struct omap_dm_timer *timer)
         /* Assume v1 ip if bits [31:16] are zero */
         tidr = __raw_readl(timer->io_base);
         if (!(tidr >> 16)) {
+                timer->revision = 1;
                 timer->sys_stat = timer->io_base +
                                 OMAP_TIMER_V1_SYS_STAT_OFFSET;
                 timer->irq_stat = timer->io_base + OMAP_TIMER_V1_STAT_OFFSET;
@@ -286,6 +320,7 @@ static inline void __omap_dm_timer_init_regs(struct omap_dm_timer *timer)
                 timer->pend = timer->io_base + _OMAP_TIMER_WRITE_PEND_OFFSET;
                 timer->func_base = timer->io_base;
         } else {
+                timer->revision = 2;
                 timer->sys_stat = 0;
                 timer->irq_stat = timer->io_base + OMAP_TIMER_V2_IRQSTATUS;
                 timer->irq_ena = timer->io_base + OMAP_TIMER_V2_IRQENABLE_SET;