diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/clocksource/timer-ti-dm.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c index 33609be0b304..530b71f3ab37 100644 --- a/drivers/clocksource/timer-ti-dm.c +++ b/drivers/clocksource/timer-ti-dm.c @@ -44,6 +44,121 @@ enum { REQUEST_BY_NODE, }; +static inline u32 __omap_dm_timer_read(struct omap_dm_timer *timer, u32 reg, + int posted) +{ + if (posted) + while (readl_relaxed(timer->pend) & (reg >> WPSHIFT)) + cpu_relax(); + + return readl_relaxed(timer->func_base + (reg & 0xff)); +} + +static inline void __omap_dm_timer_write(struct omap_dm_timer *timer, + u32 reg, u32 val, int posted) +{ + if (posted) + while (readl_relaxed(timer->pend) & (reg >> WPSHIFT)) + cpu_relax(); + + writel_relaxed(val, timer->func_base + (reg & 0xff)); +} + +static inline void __omap_dm_timer_init_regs(struct omap_dm_timer *timer) +{ + u32 tidr; + + /* Assume v1 ip if bits [31:16] are zero */ + tidr = readl_relaxed(timer->io_base); + if (!(tidr >> 16)) { + timer->revision = 1; + timer->irq_stat = timer->io_base + OMAP_TIMER_V1_STAT_OFFSET; + timer->irq_ena = timer->io_base + OMAP_TIMER_V1_INT_EN_OFFSET; + timer->irq_dis = timer->io_base + OMAP_TIMER_V1_INT_EN_OFFSET; + timer->pend = timer->io_base + _OMAP_TIMER_WRITE_PEND_OFFSET; + timer->func_base = timer->io_base; + } else { + timer->revision = 2; + timer->irq_stat = timer->io_base + OMAP_TIMER_V2_IRQSTATUS; + timer->irq_ena = timer->io_base + OMAP_TIMER_V2_IRQENABLE_SET; + timer->irq_dis = timer->io_base + OMAP_TIMER_V2_IRQENABLE_CLR; + timer->pend = timer->io_base + + _OMAP_TIMER_WRITE_PEND_OFFSET + + OMAP_TIMER_V2_FUNC_OFFSET; + timer->func_base = timer->io_base + OMAP_TIMER_V2_FUNC_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) { + timer->posted = OMAP_TIMER_NONPOSTED; + __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0, 0); + return; + } + + __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, + OMAP_TIMER_CTRL_POSTED, 0); + timer->context.tsicr = OMAP_TIMER_CTRL_POSTED; + timer->posted = OMAP_TIMER_POSTED; +} + +static inline void __omap_dm_timer_stop(struct omap_dm_timer *timer, + int posted, unsigned long rate) +{ + u32 l; + + l = __omap_dm_timer_read(timer, OMAP_TIMER_CTRL_REG, posted); + if (l & OMAP_TIMER_CTRL_ST) { + l &= ~0x1; + __omap_dm_timer_write(timer, OMAP_TIMER_CTRL_REG, l, posted); +#ifdef CONFIG_ARCH_OMAP2PLUS + /* Readback to make sure write has completed */ + __omap_dm_timer_read(timer, OMAP_TIMER_CTRL_REG, posted); + /* + * Wait for functional clock period x 3.5 to make sure that + * timer is stopped + */ + udelay(3500000 / rate + 1); +#endif + } + + /* Ack possibly pending interrupt */ + writel_relaxed(OMAP_TIMER_INT_OVERFLOW, timer->irq_stat); +} + +static inline void __omap_dm_timer_int_enable(struct omap_dm_timer *timer, + unsigned int value) +{ + writel_relaxed(value, timer->irq_ena); + __omap_dm_timer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, value, 0); +} + +static inline unsigned int +__omap_dm_timer_read_counter(struct omap_dm_timer *timer, int posted) +{ + return __omap_dm_timer_read(timer, OMAP_TIMER_COUNTER_REG, posted); +} + +static inline void __omap_dm_timer_write_status(struct omap_dm_timer *timer, + unsigned int value) +{ + writel_relaxed(value, timer->irq_stat); +} + /** * omap_dm_timer_read_reg - read timer registers in posted and non-posted mode * @timer: timer pointer over which read operation to perform |