diff options
Diffstat (limited to 'drivers/clocksource/time-armada-370-xp.c')
| -rw-r--r-- | drivers/clocksource/time-armada-370-xp.c | 248 |
1 files changed, 168 insertions, 80 deletions
diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c index 4674f94957c..0451e62fac7 100644 --- a/drivers/clocksource/time-armada-370-xp.c +++ b/drivers/clocksource/time-armada-370-xp.c @@ -13,11 +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> @@ -26,19 +41,20 @@ #include <linux/of_address.h> #include <linux/irq.h> #include <linux/module.h> -#include <asm/sched_clock.h> +#include <linux/sched_clock.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) @@ -48,6 +64,7 @@ #define TIMER1_RELOAD_OFF 0x0018 #define TIMER1_VAL_OFF 0x001c +#define LCL_TIMER_EVENTS_STATUS 0x0028 /* Global timers are connected to the coherency fabric clock, and the below divider reduces their incrementing frequency. */ #define TIMER_DIVIDER_SHIFT 5 @@ -56,15 +73,25 @@ /* * SoC-specific data. */ -static void __iomem *timer_base; -static int timer_irq; +static void __iomem *timer_base, *local_base; +static unsigned int timer_clk; +static bool timer25Mhz = true; +static u32 enable_mask; /* * Number of timer ticks per jiffy. */ static u32 ticks_per_jiffy; -static u32 notrace armada_370_xp_read_sched_clock(void) +static struct clock_event_device __percpu *armada_370_xp_evt; + +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 u64 notrace armada_370_xp_read_sched_clock(void) { return ~readl(timer_base + TIMER0_VAL_OFF); } @@ -76,26 +103,20 @@ static int armada_370_xp_clkevt_next_event(unsigned long delta, struct clock_event_device *dev) { - u32 u; - /* * Clear clockevent timer interrupt. */ - writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS); + writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); /* * Setup new clockevent timer value. */ - writel(delta, timer_base + TIMER1_VAL_OFF); + writel(delta, local_base + TIMER0_VAL_OFF); /* * Enable the timer. */ - u = readl(timer_base + TIMER_CTRL_OFF); - u = ((u & ~TIMER1_RELOAD_EN) | TIMER1_EN | - TIMER1_DIV(TIMER_DIVIDER_SHIFT)); - writel(u, timer_base + TIMER_CTRL_OFF); - + local_timer_ctrl_clrset(TIMER0_RELOAD_EN, enable_mask); return 0; } @@ -103,101 +124,131 @@ 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) { + /* * Setup timer to fire at 1/HZ intervals. */ - writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF); - writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF); + writel(ticks_per_jiffy - 1, local_base + TIMER0_RELOAD_OFF); + writel(ticks_per_jiffy - 1, local_base + TIMER0_VAL_OFF); /* * Enable timer. */ - u = readl(timer_base + TIMER_CTRL_OFF); - - writel((u | TIMER1_EN | TIMER1_RELOAD_EN | - TIMER1_DIV(TIMER_DIVIDER_SHIFT)), - timer_base + TIMER_CTRL_OFF); + local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask); } else { /* * Disable timer. */ - u = readl(timer_base + TIMER_CTRL_OFF); - writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF); + local_timer_ctrl_clrset(TIMER0_EN, 0); /* * ACK pending timer interrupt. */ - writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS); - + writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); } } -static struct clock_event_device armada_370_xp_clkevt = { - .name = "armada_370_xp_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 = dev_id; - writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS); - armada_370_xp_clkevt.event_handler(&armada_370_xp_clkevt); + writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); + evt->event_handler(evt); return IRQ_HANDLED; } -static struct irqaction armada_370_xp_timer_irq = { - .name = "armada_370_xp_tick", - .flags = IRQF_DISABLED | IRQF_TIMER, - .handler = armada_370_xp_timer_interrupt +/* + * Setup the local clock events for a CPU. + */ +static int armada_370_xp_timer_setup(struct clock_event_device *evt) +{ + u32 clr = 0, set = 0; + int cpu = smp_processor_id(); + + if (timer25Mhz) + set = TIMER0_25MHZ; + else + 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); + + 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) +{ + evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt); + disable_percpu_irq(evt->irq); +} + +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; - unsigned int timer_clk; - int ret; - np = of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-timer"); + u32 clr = 0, set = 0; + int res; + 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(timer_base + TIMER_CTRL_OFF); - writel(u | TIMER0_25MHZ | TIMER1_25MHZ, - timer_base + TIMER_CTRL_OFF); - timer_clk = 25000000; + if (timer25Mhz) { + set = TIMER0_25MHZ; + enable_mask = TIMER0_EN; } else { - u32 clk = 0; - ret = of_property_read_u32(np, "clock-frequency", &clk); - WARN_ON(!clk || ret < 0); - u = readl(timer_base + TIMER_CTRL_OFF); - writel(u & ~(TIMER0_25MHZ | TIMER1_25MHZ), - timer_base + TIMER_CTRL_OFF); - timer_clk = clk / TIMER_DIVIDER; + clr = TIMER0_25MHZ; + enable_mask = TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT); } - - /* We use timer 0 as clocksource, and timer 1 for - clockevents */ - timer_irq = irq_of_parse_and_map(np, 1); - - ticks_per_jiffy = (timer_clk + HZ / 2) / HZ; + atomic_io_modify(timer_base + TIMER_CTRL_OFF, clr | set, set); + local_timer_ctrl_clrset(clr, set); /* - * Set scale and timer for sched_clock. + * We use timer 0 as clocksource, and private(local) timer 0 + * for clockevents */ - setup_sched_clock(armada_370_xp_read_sched_clock, 32, timer_clk); + armada_370_xp_clkevt_irq = irq_of_parse_and_map(np, 4); + + ticks_per_jiffy = (timer_clk + HZ / 2) / HZ; /* * Setup free-running clocksource timer (interrupts @@ -206,21 +257,58 @@ 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); + atomic_io_modify(timer_base + TIMER_CTRL_OFF, + TIMER0_RELOAD_EN | enable_mask, + TIMER0_RELOAD_EN | enable_mask); - writel((u | TIMER0_EN | TIMER0_RELOAD_EN | - TIMER0_DIV(TIMER_DIVIDER_SHIFT)), timer_base + TIMER_CTRL_OFF); + /* + * Set scale and timer for sched_clock. + */ + sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk); clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "armada_370_xp_clocksource", timer_clk, 300, 32, clocksource_mmio_readl_down); + register_cpu_notifier(&armada_370_xp_timer_cpu_nb); + + armada_370_xp_evt = alloc_percpu(struct clock_event_device); + + /* * Setup clockevent timer (interrupt-driven). */ - setup_irq(timer_irq, &armada_370_xp_timer_irq); - armada_370_xp_clkevt.cpumask = cpumask_of(0); - clockevents_config_and_register(&armada_370_xp_clkevt, - timer_clk, 1, 0xfffffffe); + res = request_percpu_irq(armada_370_xp_clkevt_irq, + armada_370_xp_timer_interrupt, + "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); |