diff options
Diffstat (limited to 'kernel/drivers/clocksource/tcb_clksrc.c')
-rw-r--r-- | kernel/drivers/clocksource/tcb_clksrc.c | 144 |
1 files changed, 93 insertions, 51 deletions
diff --git a/kernel/drivers/clocksource/tcb_clksrc.c b/kernel/drivers/clocksource/tcb_clksrc.c index 43f1c6bc6..5b6f57f50 100644 --- a/kernel/drivers/clocksource/tcb_clksrc.c +++ b/kernel/drivers/clocksource/tcb_clksrc.c @@ -73,6 +73,7 @@ static struct clocksource clksrc = { struct tc_clkevt_device { struct clock_event_device clkevt; struct clk *clk; + bool clk_enabled; u32 freq; void __iomem *regs; }; @@ -84,56 +85,87 @@ static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt) static u32 timer_clock; -static void tc_mode(enum clock_event_mode m, struct clock_event_device *d) +static void tc_clk_disable(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + + clk_disable(tcd->clk); + tcd->clk_enabled = false; +} + +static void tc_clk_enable(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + + if (tcd->clk_enabled) + return; + clk_enable(tcd->clk); + tcd->clk_enabled = true; +} + +static int tc_shutdown(struct clock_event_device *d) { struct tc_clkevt_device *tcd = to_tc_clkevt(d); void __iomem *regs = tcd->regs; - if (tcd->clkevt.mode == CLOCK_EVT_MODE_PERIODIC - || tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) { - __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR)); - __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); - clk_disable(tcd->clk); - } + __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR)); + __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); + return 0; +} + +static int tc_shutdown_clk_off(struct clock_event_device *d) +{ + tc_shutdown(d); + if (!clockevent_state_detached(d)) + tc_clk_disable(d); + + return 0; +} + +static int tc_set_oneshot(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + void __iomem *regs = tcd->regs; + + if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) + tc_shutdown(d); + + tc_clk_enable(d); - switch (m) { + /* count up to RC, then irq and stop */ + __raw_writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE | + ATMEL_TC_WAVESEL_UP_AUTO, regs + ATMEL_TC_REG(2, CMR)); + __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); + + /* set_next_event() configures and starts the timer */ + return 0; +} + +static int tc_set_periodic(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + void __iomem *regs = tcd->regs; + + if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) + tc_shutdown(d); /* By not making the gentime core emulate periodic mode on top * of oneshot, we get lower overhead and improved accuracy. */ - case CLOCK_EVT_MODE_PERIODIC: - clk_enable(tcd->clk); - - /* count up to RC, then irq and restart */ - __raw_writel(timer_clock - | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, - regs + ATMEL_TC_REG(2, CMR)); - __raw_writel((tcd->freq + HZ / 2) / HZ, - tcaddr + ATMEL_TC_REG(2, RC)); - - /* Enable clock and interrupts on RC compare */ - __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); - - /* go go gadget! */ - __raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, - regs + ATMEL_TC_REG(2, CCR)); - break; - - case CLOCK_EVT_MODE_ONESHOT: - clk_enable(tcd->clk); - - /* count up to RC, then irq and stop */ - __raw_writel(timer_clock | ATMEL_TC_CPCSTOP - | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, - regs + ATMEL_TC_REG(2, CMR)); - __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); - - /* set_next_event() configures and starts the timer */ - break; - - default: - break; - } + tc_clk_enable(d); + + /* count up to RC, then irq and restart */ + __raw_writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, + regs + ATMEL_TC_REG(2, CMR)); + __raw_writel((tcd->freq + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC)); + + /* Enable clock and interrupts on RC compare */ + __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER)); + + /* go go gadget! */ + __raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, regs + + ATMEL_TC_REG(2, CCR)); + return 0; } static int tc_next_event(unsigned long delta, struct clock_event_device *d) @@ -148,17 +180,19 @@ static int tc_next_event(unsigned long delta, struct clock_event_device *d) static struct tc_clkevt_device clkevt = { .clkevt = { - .name = "tc_clkevt", - .features = CLOCK_EVT_FEAT_PERIODIC - | CLOCK_EVT_FEAT_ONESHOT, -#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK + .name = "tc_clkevt", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, /* Should be lower than at91rm9200's system timer */ - .rating = 125, +#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK + .rating = 125, #else - .rating = 200, + .rating = 200, #endif - .set_next_event = tc_next_event, - .set_mode = tc_mode, + .set_next_event = tc_next_event, + .set_state_shutdown = tc_shutdown_clk_off, + .set_state_periodic = tc_set_periodic, + .set_state_oneshot = tc_set_oneshot, }, }; @@ -183,10 +217,17 @@ static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx) struct clk *t2_clk = tc->clk[2]; int irq = tc->irq[2]; + ret = clk_prepare_enable(tc->slow_clk); + if (ret) + return ret; + /* try to enable t2 clk to avoid future errors in mode change */ ret = clk_prepare_enable(t2_clk); - if (ret) + if (ret) { + clk_disable_unprepare(tc->slow_clk); return ret; + } + clk_disable(t2_clk); clkevt.regs = tc->regs; @@ -202,7 +243,8 @@ static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx) ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt); if (ret) { - clk_disable_unprepare(t2_clk); + clk_unprepare(t2_clk); + clk_disable_unprepare(tc->slow_clk); return ret; } |