diff options
Diffstat (limited to 'arch/arm/plat-omap/include/plat')
| -rw-r--r-- | arch/arm/plat-omap/include/plat/dmtimer.h | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h index 1bee0ac8876..ac16f1e9d0e 100644 --- a/arch/arm/plat-omap/include/plat/dmtimer.h +++ b/arch/arm/plat-omap/include/plat/dmtimer.h @@ -66,6 +66,16 @@ #define OMAP_TIMER_NEEDS_RESET 0x10000000 #define OMAP_TIMER_HAS_DSP_IRQ 0x08000000 +/* + * timer errata flags + * + * Errata i103/i767 impacts all OMAP3/4/5 devices including AM33xx. This + * errata prevents us from using posted mode on these devices, unless the + * timer counter register is never read. For more details please refer to + * the OMAP3/4/5 errata documents. + */ +#define OMAP_TIMER_ERRATA_I103_I767 0x80000000 + struct omap_timer_capability_dev_attr { u32 timer_capability; }; @@ -97,6 +107,7 @@ struct timer_regs { struct dmtimer_platform_data { /* set_timer_src - Only used for OMAP1 devices */ int (*set_timer_src)(struct platform_device *pdev, int source); + u32 timer_errata; u32 timer_capability; int (*get_context_loss_count)(struct device *); }; @@ -273,6 +284,7 @@ struct omap_dm_timer { int ctx_loss_count; int revision; u32 capability; + u32 errata; struct platform_device *pdev; struct list_head node; }; @@ -344,10 +356,46 @@ static inline void __omap_dm_timer_reset(struct omap_dm_timer *timer, l |= 1 << 2; __raw_writel(l, timer->io_base + OMAP_TIMER_OCP_CFG_OFFSET); +} + +/* + * __omap_dm_timer_enable_posted - enables write posted mode + * @timer: pointer to timer instance handle + * + * Enables the write posted mode for the timer. When posted mode is enabled + * writes to certain timer registers are immediately acknowledged by the + * internal bus and hence prevents stalling the CPU waiting for the write to + * complete. Enabling this feature can improve performance for writing to the + * timer registers. + */ +static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer) +{ + if (timer->posted) + return; + + if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) + return; - /* Match hardware reset default of posted mode */ __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, - OMAP_TIMER_CTRL_POSTED, 0); + OMAP_TIMER_CTRL_POSTED, 0); + timer->context.tsicr = OMAP_TIMER_CTRL_POSTED; + timer->posted = OMAP_TIMER_POSTED; +} + +/** + * __omap_dm_timer_override_errata - override errata flags for a timer + * @timer: pointer to timer handle + * @errata: errata flags to be ignored + * + * For a given timer, override a timer errata by clearing the flags + * specified by the errata argument. A specific erratum should only be + * overridden for a timer if the timer is used in such a way the erratum + * has no impact. + */ +static inline void __omap_dm_timer_override_errata(struct omap_dm_timer *timer, + u32 errata) +{ + timer->errata &= ~errata; } static inline int __omap_dm_timer_set_source(struct clk *timer_fck, |