diff options
Diffstat (limited to 'drivers/clocksource/time-armada-370-xp.c')
| -rw-r--r-- | drivers/clocksource/time-armada-370-xp.c | 223 |
1 files changed, 120 insertions, 103 deletions
diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c index 1b04b7e1d39..0198504ef6b 100644 --- a/drivers/clocksource/time-armada-370-xp.c +++ b/drivers/clocksource/time-armada-370-xp.c @@ -13,12 +13,26 @@ * * Timer 0 is used as free-running clocksource, while timer 1 is * used as clock_event_device. + * + * --- + * Clocksource driver for Armada 370 and Armada XP SoC. + * This driver implements one compatible string for each SoC, given + * each has its own characteristics: + * + * * Armada 370 has no 25 MHz fixed timer. + * + * * Armada XP cannot work properly without such 25 MHz fixed timer as + * doing otherwise leads to using a clocksource whose frequency varies + * when doing cpufreq frequency changes. + * + * See Documentation/devicetree/bindings/timer/marvell,armada-370-xp-timer.txt */ #include <linux/init.h> #include <linux/platform_device.h> #include <linux/kernel.h> #include <linux/clk.h> +#include <linux/cpu.h> #include <linux/timer.h> #include <linux/clockchips.h> #include <linux/interrupt.h> @@ -28,20 +42,19 @@ #include <linux/irq.h> #include <linux/module.h> #include <linux/sched_clock.h> - -#include <asm/localtimer.h> #include <linux/percpu.h> + /* * Timer block registers. */ #define TIMER_CTRL_OFF 0x0000 -#define TIMER0_EN 0x0001 -#define TIMER0_RELOAD_EN 0x0002 -#define TIMER0_25MHZ 0x0800 +#define TIMER0_EN BIT(0) +#define TIMER0_RELOAD_EN BIT(1) +#define TIMER0_25MHZ BIT(11) #define TIMER0_DIV(div) ((div) << 19) -#define TIMER1_EN 0x0004 -#define TIMER1_RELOAD_EN 0x0008 -#define TIMER1_25MHZ 0x1000 +#define TIMER1_EN BIT(2) +#define TIMER1_RELOAD_EN BIT(3) +#define TIMER1_25MHZ BIT(12) #define TIMER1_DIV(div) ((div) << 22) #define TIMER_EVENTS_STATUS 0x0004 #define TIMER0_CLR_MASK (~0x1) @@ -69,7 +82,19 @@ static bool timer25Mhz = true; */ static u32 ticks_per_jiffy; -static struct clock_event_device __percpu **percpu_armada_370_xp_evt; +static struct clock_event_device __percpu *armada_370_xp_evt; + +static void timer_ctrl_clrset(u32 clr, u32 set) +{ + writel((readl(timer_base + TIMER_CTRL_OFF) & ~clr) | set, + timer_base + TIMER_CTRL_OFF); +} + +static void local_timer_ctrl_clrset(u32 clr, u32 set) +{ + writel((readl(local_base + TIMER_CTRL_OFF) & ~clr) | set, + local_base + TIMER_CTRL_OFF); +} static u32 notrace armada_370_xp_read_sched_clock(void) { @@ -83,7 +108,6 @@ static int armada_370_xp_clkevt_next_event(unsigned long delta, struct clock_event_device *dev) { - u32 u; /* * Clear clockevent timer interrupt. */ @@ -97,11 +121,8 @@ armada_370_xp_clkevt_next_event(unsigned long delta, /* * Enable the timer. */ - u = readl(local_base + TIMER_CTRL_OFF); - u = ((u & ~TIMER0_RELOAD_EN) | TIMER0_EN | - TIMER0_DIV(TIMER_DIVIDER_SHIFT)); - writel(u, local_base + TIMER_CTRL_OFF); - + local_timer_ctrl_clrset(TIMER0_RELOAD_EN, + TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT)); return 0; } @@ -109,8 +130,6 @@ static void armada_370_xp_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev) { - u32 u; - if (mode == CLOCK_EVT_MODE_PERIODIC) { /* @@ -122,18 +141,14 @@ armada_370_xp_clkevt_mode(enum clock_event_mode mode, /* * Enable timer. */ - - u = readl(local_base + TIMER_CTRL_OFF); - - writel((u | TIMER0_EN | TIMER0_RELOAD_EN | - TIMER0_DIV(TIMER_DIVIDER_SHIFT)), - local_base + TIMER_CTRL_OFF); + local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | + TIMER0_EN | + TIMER0_DIV(TIMER_DIVIDER_SHIFT)); } else { /* * Disable timer. */ - u = readl(local_base + TIMER_CTRL_OFF); - writel(u & ~TIMER0_EN, local_base + TIMER_CTRL_OFF); + local_timer_ctrl_clrset(TIMER0_EN, 0); /* * ACK pending timer interrupt. @@ -142,21 +157,14 @@ armada_370_xp_clkevt_mode(enum clock_event_mode mode, } } -static struct clock_event_device armada_370_xp_clkevt = { - .name = "armada_370_xp_per_cpu_tick", - .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, - .shift = 32, - .rating = 300, - .set_next_event = armada_370_xp_clkevt_next_event, - .set_mode = armada_370_xp_clkevt_mode, -}; +static int armada_370_xp_clkevt_irq; static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id) { /* * ACK timer interrupt and call event handler. */ - struct clock_event_device *evt = *(struct clock_event_device **)dev_id; + struct clock_event_device *evt = dev_id; writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); evt->event_handler(evt); @@ -169,89 +177,81 @@ static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id) */ static int armada_370_xp_timer_setup(struct clock_event_device *evt) { - u32 u; + u32 clr = 0, set = 0; int cpu = smp_processor_id(); - /* Use existing clock_event for cpu 0 */ - if (!smp_processor_id()) - return 0; - - u = readl(local_base + TIMER_CTRL_OFF); if (timer25Mhz) - writel(u | TIMER0_25MHZ, local_base + TIMER_CTRL_OFF); + set = TIMER0_25MHZ; else - writel(u & ~TIMER0_25MHZ, local_base + TIMER_CTRL_OFF); - - evt->name = armada_370_xp_clkevt.name; - evt->irq = armada_370_xp_clkevt.irq; - evt->features = armada_370_xp_clkevt.features; - evt->shift = armada_370_xp_clkevt.shift; - evt->rating = armada_370_xp_clkevt.rating, + clr = TIMER0_25MHZ; + local_timer_ctrl_clrset(clr, set); + + evt->name = "armada_370_xp_per_cpu_tick", + evt->features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_PERIODIC; + evt->shift = 32, + evt->rating = 300, evt->set_next_event = armada_370_xp_clkevt_next_event, evt->set_mode = armada_370_xp_clkevt_mode, + evt->irq = armada_370_xp_clkevt_irq; evt->cpumask = cpumask_of(cpu); - *__this_cpu_ptr(percpu_armada_370_xp_evt) = evt; - clockevents_config_and_register(evt, timer_clk, 1, 0xfffffffe); enable_percpu_irq(evt->irq, 0); return 0; } -static void armada_370_xp_timer_stop(struct clock_event_device *evt) +static void armada_370_xp_timer_stop(struct clock_event_device *evt) { evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt); disable_percpu_irq(evt->irq); } -static struct local_timer_ops armada_370_xp_local_timer_ops = { - .setup = armada_370_xp_timer_setup, - .stop = armada_370_xp_timer_stop, +static int armada_370_xp_timer_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + /* + * Grab cpu pointer in each case to avoid spurious + * preemptible warnings + */ + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_STARTING: + armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt)); + break; + case CPU_DYING: + armada_370_xp_timer_stop(this_cpu_ptr(armada_370_xp_evt)); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block armada_370_xp_timer_cpu_nb = { + .notifier_call = armada_370_xp_timer_cpu_notify, }; -void __init armada_370_xp_timer_init(void) +static void __init armada_370_xp_timer_common_init(struct device_node *np) { - u32 u; - struct device_node *np; + u32 clr = 0, set = 0; int res; - np = of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-timer"); timer_base = of_iomap(np, 0); WARN_ON(!timer_base); local_base = of_iomap(np, 1); - if (of_find_property(np, "marvell,timer-25Mhz", NULL)) { - /* The fixed 25MHz timer is available so let's use it */ - u = readl(local_base + TIMER_CTRL_OFF); - writel(u | TIMER0_25MHZ, - local_base + TIMER_CTRL_OFF); - u = readl(timer_base + TIMER_CTRL_OFF); - writel(u | TIMER0_25MHZ, - timer_base + TIMER_CTRL_OFF); - timer_clk = 25000000; - } else { - unsigned long rate = 0; - struct clk *clk = of_clk_get(np, 0); - WARN_ON(IS_ERR(clk)); - rate = clk_get_rate(clk); - u = readl(local_base + TIMER_CTRL_OFF); - writel(u & ~(TIMER0_25MHZ), - local_base + TIMER_CTRL_OFF); - - u = readl(timer_base + TIMER_CTRL_OFF); - writel(u & ~(TIMER0_25MHZ), - timer_base + TIMER_CTRL_OFF); - - timer_clk = rate / TIMER_DIVIDER; - timer25Mhz = false; - } + if (timer25Mhz) + set = TIMER0_25MHZ; + else + clr = TIMER0_25MHZ; + timer_ctrl_clrset(clr, set); + local_timer_ctrl_clrset(clr, set); /* * We use timer 0 as clocksource, and private(local) timer 0 * for clockevents */ - armada_370_xp_clkevt.irq = irq_of_parse_and_map(np, 4); + armada_370_xp_clkevt_irq = irq_of_parse_and_map(np, 4); ticks_per_jiffy = (timer_clk + HZ / 2) / HZ; @@ -267,35 +267,52 @@ void __init armada_370_xp_timer_init(void) writel(0xffffffff, timer_base + TIMER0_VAL_OFF); writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF); - u = readl(timer_base + TIMER_CTRL_OFF); - - writel((u | TIMER0_EN | TIMER0_RELOAD_EN | - TIMER0_DIV(TIMER_DIVIDER_SHIFT)), timer_base + TIMER_CTRL_OFF); + timer_ctrl_clrset(0, TIMER0_EN | TIMER0_RELOAD_EN | + TIMER0_DIV(TIMER_DIVIDER_SHIFT)); clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "armada_370_xp_clocksource", timer_clk, 300, 32, clocksource_mmio_readl_down); - /* Register the clockevent on the private timer of CPU 0 */ - armada_370_xp_clkevt.cpumask = cpumask_of(0); - clockevents_config_and_register(&armada_370_xp_clkevt, - timer_clk, 1, 0xfffffffe); + register_cpu_notifier(&armada_370_xp_timer_cpu_nb); - percpu_armada_370_xp_evt = alloc_percpu(struct clock_event_device *); + armada_370_xp_evt = alloc_percpu(struct clock_event_device); /* * Setup clockevent timer (interrupt-driven). */ - *__this_cpu_ptr(percpu_armada_370_xp_evt) = &armada_370_xp_clkevt; - res = request_percpu_irq(armada_370_xp_clkevt.irq, + res = request_percpu_irq(armada_370_xp_clkevt_irq, armada_370_xp_timer_interrupt, - armada_370_xp_clkevt.name, - percpu_armada_370_xp_evt); - if (!res) { - enable_percpu_irq(armada_370_xp_clkevt.irq, 0); -#ifdef CONFIG_LOCAL_TIMERS - local_timer_register(&armada_370_xp_local_timer_ops); -#endif - } + "armada_370_xp_per_cpu_tick", + armada_370_xp_evt); + /* Immediately configure the timer on the boot CPU */ + if (!res) + armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt)); +} + +static void __init armada_xp_timer_init(struct device_node *np) +{ + struct clk *clk = of_clk_get_by_name(np, "fixed"); + + /* The 25Mhz fixed clock is mandatory, and must always be available */ + BUG_ON(IS_ERR(clk)); + timer_clk = clk_get_rate(clk); + + armada_370_xp_timer_common_init(np); +} +CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer", + armada_xp_timer_init); + +static void __init armada_370_timer_init(struct device_node *np) +{ + struct clk *clk = of_clk_get(np, 0); + + BUG_ON(IS_ERR(clk)); + timer_clk = clk_get_rate(clk) / TIMER_DIVIDER; + timer25Mhz = false; + + armada_370_xp_timer_common_init(np); } +CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer", + armada_370_timer_init); |