--- zzzz-none-000/linux-3.10.107/drivers/clocksource/cadence_ttc_timer.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/clocksource/cadence_ttc_timer.c 2021-02-04 17:41:59.000000000 +0000 @@ -21,10 +21,10 @@ #include #include #include -#include +#include /* - * This driver configures the 2 16-bit count-up timers as follows: + * This driver configures the 2 16/32-bit count-up timers as follows: * * T1: Timer 1, clocksource for generic timekeeping * T2: Timer 2, clockevent source for hrtimers @@ -51,6 +51,10 @@ #define TTC_CNT_CNTRL_DISABLE_MASK 0x1 +#define TTC_CLK_CNTRL_CSRC_MASK (1 << 5) /* clock source */ +#define TTC_CLK_CNTRL_PSV_MASK 0x1e +#define TTC_CLK_CNTRL_PSV_SHIFT 1 + /* * Setup the timers to use pre-scaling, using a fixed value for now that will * work across most input frequency, but it may need to be more dynamic @@ -61,15 +65,19 @@ #define CLK_CNTRL_PRESCALE_EN 1 #define CNT_CNTRL_RESET (1 << 4) +#define MAX_F_ERR 50 + /** * struct ttc_timer - This definition defines local timer structure * * @base_addr: Base address of timer + * @freq: Timer input clock frequency * @clk: Associated clock source * @clk_rate_change_nb Notifier block for clock rate changes */ struct ttc_timer { void __iomem *base_addr; + unsigned long freq; struct clk *clk; struct notifier_block clk_rate_change_nb; }; @@ -78,6 +86,8 @@ container_of(x, struct ttc_timer, clk_rate_change_nb) struct ttc_timer_clocksource { + u32 scale_clk_ctrl_reg_old; + u32 scale_clk_ctrl_reg_new; struct ttc_timer ttc; struct clocksource cs; }; @@ -93,6 +103,8 @@ #define to_ttc_timer_clkevent(x) \ container_of(x, struct ttc_timer_clockevent, ce) +static void __iomem *ttc_sched_clock_val_reg; + /** * ttc_set_interval - Set the timer interval value * @@ -105,11 +117,11 @@ u32 ctrl_reg; /* Disable the counter, set the counter value and re-enable counter */ - ctrl_reg = __raw_readl(timer->base_addr + TTC_CNT_CNTRL_OFFSET); + ctrl_reg = readl_relaxed(timer->base_addr + TTC_CNT_CNTRL_OFFSET); ctrl_reg |= TTC_CNT_CNTRL_DISABLE_MASK; - __raw_writel(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET); + writel_relaxed(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET); - __raw_writel(cycles, timer->base_addr + TTC_INTR_VAL_OFFSET); + writel_relaxed(cycles, timer->base_addr + TTC_INTR_VAL_OFFSET); /* * Reset the counter (0x10) so that it starts from 0, one-shot @@ -117,7 +129,7 @@ */ ctrl_reg |= CNT_CNTRL_RESET; ctrl_reg &= ~TTC_CNT_CNTRL_DISABLE_MASK; - __raw_writel(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET); + writel_relaxed(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET); } /** @@ -134,7 +146,7 @@ struct ttc_timer *timer = &ttce->ttc; /* Acknowledge the interrupt and call event handler */ - __raw_readl(timer->base_addr + TTC_ISR_OFFSET); + readl_relaxed(timer->base_addr + TTC_ISR_OFFSET); ttce->ce.event_handler(&ttce->ce); @@ -150,10 +162,15 @@ { struct ttc_timer *timer = &to_ttc_timer_clksrc(cs)->ttc; - return (cycle_t)__raw_readl(timer->base_addr + + return (cycle_t)readl_relaxed(timer->base_addr + TTC_COUNT_VAL_OFFSET); } +static u64 notrace ttc_sched_clock_read(void) +{ + return readl_relaxed(ttc_sched_clock_val_reg); +} + /** * ttc_set_next_event - Sets the time interval for next event * @@ -173,41 +190,42 @@ } /** - * ttc_set_mode - Sets the mode of timer + * ttc_set_{shutdown|oneshot|periodic} - Sets the state of timer * - * @mode: Mode to be set * @evt: Address of clock event instance **/ -static void ttc_set_mode(enum clock_event_mode mode, - struct clock_event_device *evt) +static int ttc_shutdown(struct clock_event_device *evt) { struct ttc_timer_clockevent *ttce = to_ttc_timer_clkevent(evt); struct ttc_timer *timer = &ttce->ttc; u32 ctrl_reg; - switch (mode) { - case CLOCK_EVT_MODE_PERIODIC: - ttc_set_interval(timer, - DIV_ROUND_CLOSEST(clk_get_rate(ttce->ttc.clk), - PRESCALE * HZ)); - break; - case CLOCK_EVT_MODE_ONESHOT: - case CLOCK_EVT_MODE_UNUSED: - case CLOCK_EVT_MODE_SHUTDOWN: - ctrl_reg = __raw_readl(timer->base_addr + - TTC_CNT_CNTRL_OFFSET); - ctrl_reg |= TTC_CNT_CNTRL_DISABLE_MASK; - __raw_writel(ctrl_reg, - timer->base_addr + TTC_CNT_CNTRL_OFFSET); - break; - case CLOCK_EVT_MODE_RESUME: - ctrl_reg = __raw_readl(timer->base_addr + - TTC_CNT_CNTRL_OFFSET); - ctrl_reg &= ~TTC_CNT_CNTRL_DISABLE_MASK; - __raw_writel(ctrl_reg, - timer->base_addr + TTC_CNT_CNTRL_OFFSET); - break; - } + ctrl_reg = readl_relaxed(timer->base_addr + TTC_CNT_CNTRL_OFFSET); + ctrl_reg |= TTC_CNT_CNTRL_DISABLE_MASK; + writel_relaxed(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET); + return 0; +} + +static int ttc_set_periodic(struct clock_event_device *evt) +{ + struct ttc_timer_clockevent *ttce = to_ttc_timer_clkevent(evt); + struct ttc_timer *timer = &ttce->ttc; + + ttc_set_interval(timer, + DIV_ROUND_CLOSEST(ttce->ttc.freq, PRESCALE * HZ)); + return 0; +} + +static int ttc_resume(struct clock_event_device *evt) +{ + struct ttc_timer_clockevent *ttce = to_ttc_timer_clkevent(evt); + struct ttc_timer *timer = &ttce->ttc; + u32 ctrl_reg; + + ctrl_reg = readl_relaxed(timer->base_addr + TTC_CNT_CNTRL_OFFSET); + ctrl_reg &= ~TTC_CNT_CNTRL_DISABLE_MASK; + writel_relaxed(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET); + return 0; } static int ttc_rate_change_clocksource_cb(struct notifier_block *nb, @@ -219,35 +237,93 @@ struct ttc_timer_clocksource, ttc); switch (event) { - case POST_RATE_CHANGE: + case PRE_RATE_CHANGE: + { + u32 psv; + unsigned long factor, rate_low, rate_high; + + if (ndata->new_rate > ndata->old_rate) { + factor = DIV_ROUND_CLOSEST(ndata->new_rate, + ndata->old_rate); + rate_low = ndata->old_rate; + rate_high = ndata->new_rate; + } else { + factor = DIV_ROUND_CLOSEST(ndata->old_rate, + ndata->new_rate); + rate_low = ndata->new_rate; + rate_high = ndata->old_rate; + } + + if (!is_power_of_2(factor)) + return NOTIFY_BAD; + + if (abs(rate_high - (factor * rate_low)) > MAX_F_ERR) + return NOTIFY_BAD; + + factor = __ilog2_u32(factor); + /* - * Do whatever is necessary to maintain a proper time base - * - * I cannot find a way to adjust the currently used clocksource - * to the new frequency. __clocksource_updatefreq_hz() sounds - * good, but does not work. Not sure what's that missing. - * - * This approach works, but triggers two clocksource switches. - * The first after unregister to clocksource jiffies. And - * another one after the register to the newly registered timer. - * - * Alternatively we could 'waste' another HW timer to ping pong - * between clock sources. That would also use one register and - * one unregister call, but only trigger one clocksource switch - * for the cost of another HW timer used by the OS. + * store timer clock ctrl register so we can restore it in case + * of an abort. */ - clocksource_unregister(&ttccs->cs); - clocksource_register_hz(&ttccs->cs, - ndata->new_rate / PRESCALE); - /* fall through */ - case PRE_RATE_CHANGE: + ttccs->scale_clk_ctrl_reg_old = + readl_relaxed(ttccs->ttc.base_addr + + TTC_CLK_CNTRL_OFFSET); + + psv = (ttccs->scale_clk_ctrl_reg_old & + TTC_CLK_CNTRL_PSV_MASK) >> + TTC_CLK_CNTRL_PSV_SHIFT; + if (ndata->new_rate < ndata->old_rate) + psv -= factor; + else + psv += factor; + + /* prescaler within legal range? */ + if (psv & ~(TTC_CLK_CNTRL_PSV_MASK >> TTC_CLK_CNTRL_PSV_SHIFT)) + return NOTIFY_BAD; + + ttccs->scale_clk_ctrl_reg_new = ttccs->scale_clk_ctrl_reg_old & + ~TTC_CLK_CNTRL_PSV_MASK; + ttccs->scale_clk_ctrl_reg_new |= psv << TTC_CLK_CNTRL_PSV_SHIFT; + + + /* scale down: adjust divider in post-change notification */ + if (ndata->new_rate < ndata->old_rate) + return NOTIFY_DONE; + + /* scale up: adjust divider now - before frequency change */ + writel_relaxed(ttccs->scale_clk_ctrl_reg_new, + ttccs->ttc.base_addr + TTC_CLK_CNTRL_OFFSET); + break; + } + case POST_RATE_CHANGE: + /* scale up: pre-change notification did the adjustment */ + if (ndata->new_rate > ndata->old_rate) + return NOTIFY_OK; + + /* scale down: adjust divider now - after frequency change */ + writel_relaxed(ttccs->scale_clk_ctrl_reg_new, + ttccs->ttc.base_addr + TTC_CLK_CNTRL_OFFSET); + break; + case ABORT_RATE_CHANGE: + /* we have to undo the adjustment in case we scale up */ + if (ndata->new_rate < ndata->old_rate) + return NOTIFY_OK; + + /* restore original register value */ + writel_relaxed(ttccs->scale_clk_ctrl_reg_old, + ttccs->ttc.base_addr + TTC_CLK_CNTRL_OFFSET); + /* fall through */ default: return NOTIFY_DONE; } + + return NOTIFY_DONE; } -static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base) +static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base, + u32 timer_width) { struct ttc_timer_clocksource *ttccs; int err; @@ -264,6 +340,8 @@ return; } + ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk); + ttccs->ttc.clk_rate_change_nb.notifier_call = ttc_rate_change_clocksource_cb; ttccs->ttc.clk_rate_change_nb.next = NULL; @@ -275,7 +353,7 @@ ttccs->cs.name = "ttc_clocksource"; ttccs->cs.rating = 200; ttccs->cs.read = __ttc_clocksource_read; - ttccs->cs.mask = CLOCKSOURCE_MASK(16); + ttccs->cs.mask = CLOCKSOURCE_MASK(timer_width); ttccs->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS; /* @@ -283,18 +361,21 @@ * with no interrupt and it rolls over at 0xFFFF. Pre-scale * it by 32 also. Let it start running now. */ - __raw_writel(0x0, ttccs->ttc.base_addr + TTC_IER_OFFSET); - __raw_writel(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN, + writel_relaxed(0x0, ttccs->ttc.base_addr + TTC_IER_OFFSET); + writel_relaxed(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN, ttccs->ttc.base_addr + TTC_CLK_CNTRL_OFFSET); - __raw_writel(CNT_CNTRL_RESET, + writel_relaxed(CNT_CNTRL_RESET, ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET); - err = clocksource_register_hz(&ttccs->cs, - clk_get_rate(ttccs->ttc.clk) / PRESCALE); + err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE); if (WARN_ON(err)) { kfree(ttccs); return; } + + ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET; + sched_clock_register(ttc_sched_clock_read, timer_width, + ttccs->ttc.freq / PRESCALE); } static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, @@ -307,22 +388,12 @@ switch (event) { case POST_RATE_CHANGE: - { - unsigned long flags; + /* update cached frequency */ + ttc->freq = ndata->new_rate; - /* - * clockevents_update_freq should be called with IRQ disabled on - * the CPU the timer provides events for. The timer we use is - * common to both CPUs, not sure if we need to run on both - * cores. - */ - local_irq_save(flags); - clockevents_update_freq(&ttcce->ce, - ndata->new_rate / PRESCALE); - local_irq_restore(flags); + clockevents_update_freq(&ttcce->ce, ndata->new_rate / PRESCALE); /* fall through */ - } case PRE_RATE_CHANGE: case ABORT_RATE_CHANGE: default: @@ -354,12 +425,16 @@ if (clk_notifier_register(ttcce->ttc.clk, &ttcce->ttc.clk_rate_change_nb)) pr_warn("Unable to register clock notifier.\n"); + ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk); ttcce->ttc.base_addr = base; ttcce->ce.name = "ttc_clockevent"; ttcce->ce.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; ttcce->ce.set_next_event = ttc_set_next_event; - ttcce->ce.set_mode = ttc_set_mode; + ttcce->ce.set_state_shutdown = ttc_shutdown; + ttcce->ce.set_state_periodic = ttc_set_periodic; + ttcce->ce.set_state_oneshot = ttc_shutdown; + ttcce->ce.tick_resume = ttc_resume; ttcce->ce.rating = 200; ttcce->ce.irq = irq; ttcce->ce.cpumask = cpu_possible_mask; @@ -369,21 +444,20 @@ * is prescaled by 32 using the interval interrupt. Leave it * disabled for now. */ - __raw_writel(0x23, ttcce->ttc.base_addr + TTC_CNT_CNTRL_OFFSET); - __raw_writel(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN, + writel_relaxed(0x23, ttcce->ttc.base_addr + TTC_CNT_CNTRL_OFFSET); + writel_relaxed(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN, ttcce->ttc.base_addr + TTC_CLK_CNTRL_OFFSET); - __raw_writel(0x1, ttcce->ttc.base_addr + TTC_IER_OFFSET); + writel_relaxed(0x1, ttcce->ttc.base_addr + TTC_IER_OFFSET); err = request_irq(irq, ttc_clock_event_interrupt, - IRQF_DISABLED | IRQF_TIMER, - ttcce->ce.name, ttcce); + IRQF_TIMER, ttcce->ce.name, ttcce); if (WARN_ON(err)) { kfree(ttcce); return; } clockevents_config_and_register(&ttcce->ce, - clk_get_rate(ttcce->ttc.clk) / PRESCALE, 1, 0xfffe); + ttcce->ttc.freq / PRESCALE, 1, 0xfffe); } /** @@ -396,8 +470,10 @@ { unsigned int irq; void __iomem *timer_baseaddr; - struct clk *clk; + struct clk *clk_cs, *clk_ce; static int initialized; + int clksel; + u32 timer_width = 16; if (initialized) return; @@ -421,14 +497,26 @@ BUG(); } - clk = of_clk_get_by_name(timer, "cpu_1x"); - if (IS_ERR(clk)) { + of_property_read_u32(timer, "timer-width", &timer_width); + + clksel = readl_relaxed(timer_baseaddr + TTC_CLK_CNTRL_OFFSET); + clksel = !!(clksel & TTC_CLK_CNTRL_CSRC_MASK); + clk_cs = of_clk_get(timer, clksel); + if (IS_ERR(clk_cs)) { + pr_err("ERROR: timer input clock not found\n"); + BUG(); + } + + clksel = readl_relaxed(timer_baseaddr + 4 + TTC_CLK_CNTRL_OFFSET); + clksel = !!(clksel & TTC_CLK_CNTRL_CSRC_MASK); + clk_ce = of_clk_get(timer, clksel); + if (IS_ERR(clk_ce)) { pr_err("ERROR: timer input clock not found\n"); BUG(); } - ttc_setup_clocksource(clk, timer_baseaddr); - ttc_setup_clockevent(clk, timer_baseaddr + 4, irq); + ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width); + ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq); pr_info("%s #0 at %p, irq=%d\n", timer->name, timer_baseaddr, irq); }