/* * Faraday Technology FTTMR010 timer driver * Copyright (C) 2017 Linus Walleij * * Based on a rewrite of arch/arm/mach-gemini/timer.c: * Copyright (C) 2001-2006 Storlink, Corp. * Copyright (C) 2008-2009 Paulius Zaleckas */ #include #include #include #include #include #include #include #include #include /* * Register definitions for the timers */ #define TIMER1_COUNT (0x00) #define TIMER1_LOAD (0x04) #define TIMER1_MATCH1 (0x08) #define TIMER1_MATCH2 (0x0c) #define TIMER2_COUNT (0x10) #define TIMER2_LOAD (0x14) #define TIMER2_MATCH1 (0x18) #define TIMER2_MATCH2 (0x1c) #define TIMER3_COUNT (0x20) #define TIMER3_LOAD (0x24) #define TIMER3_MATCH1 (0x28) #define TIMER3_MATCH2 (0x2c) #define TIMER_CR (0x30) #define TIMER_INTR_STATE (0x34) #define TIMER_INTR_MASK (0x38) #define TIMER_1_CR_ENABLE (1 << 0) #define TIMER_1_CR_CLOCK (1 << 1) #define TIMER_1_CR_INT (1 << 2) #define TIMER_2_CR_ENABLE (1 << 3) #define TIMER_2_CR_CLOCK (1 << 4) #define TIMER_2_CR_INT (1 << 5) #define TIMER_3_CR_ENABLE (1 << 6) #define TIMER_3_CR_CLOCK (1 << 7) #define TIMER_3_CR_INT (1 << 8) #define TIMER_1_CR_UPDOWN (1 << 9) #define TIMER_2_CR_UPDOWN (1 << 10) #define TIMER_3_CR_UPDOWN (1 << 11) #define TIMER_DEFAULT_FLAGS (TIMER_1_CR_UPDOWN | \ TIMER_3_CR_ENABLE | \ TIMER_3_CR_UPDOWN) #define TIMER_1_INT_MATCH1 (1 << 0) #define TIMER_1_INT_MATCH2 (1 << 1) #define TIMER_1_INT_OVERFLOW (1 << 2) #define TIMER_2_INT_MATCH1 (1 << 3) #define TIMER_2_INT_MATCH2 (1 << 4) #define TIMER_2_INT_OVERFLOW (1 << 5) #define TIMER_3_INT_MATCH1 (1 << 6) #define TIMER_3_INT_MATCH2 (1 << 7) #define TIMER_3_INT_OVERFLOW (1 << 8) #define TIMER_INT_ALL_MASK 0x1ff static unsigned int tick_rate; static void __iomem *base; static u64 notrace fttmr010_read_sched_clock(void) { return readl(base + TIMER3_COUNT); } static int fttmr010_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { u32 cr; /* Setup the match register */ cr = readl(base + TIMER1_COUNT); writel(cr + cycles, base + TIMER1_MATCH1); if (readl(base + TIMER1_COUNT) - cr > cycles) return -ETIME; return 0; } static int fttmr010_timer_shutdown(struct clock_event_device *evt) { u32 cr; /* * Disable also for oneshot: the set_next() call will arm the timer * instead. */ /* Stop timer and interrupt. */ cr = readl(base + TIMER_CR); cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT); writel(cr, base + TIMER_CR); /* Setup counter start from 0 */ writel(0, base + TIMER1_COUNT); writel(0, base + TIMER1_LOAD); /* enable interrupt */ cr = readl(base + TIMER_INTR_MASK); cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); cr |= TIMER_1_INT_MATCH1; writel(cr, base + TIMER_INTR_MASK); /* start the timer */ cr = readl(base + TIMER_CR); cr |= TIMER_1_CR_ENABLE; writel(cr, base + TIMER_CR); return 0; } static int fttmr010_timer_set_periodic(struct clock_event_device *evt) { u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ); u32 cr; /* Stop timer and interrupt */ cr = readl(base + TIMER_CR); cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT); writel(cr, base + TIMER_CR); /* Setup timer to fire at 1/HT intervals. */ cr = 0xffffffff - (period - 1); writel(cr, base + TIMER1_COUNT); writel(cr, base + TIMER1_LOAD); /* enable interrupt on overflow */ cr = readl(base + TIMER_INTR_MASK); cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2); cr |= TIMER_1_INT_OVERFLOW; writel(cr, base + TIMER_INTR_MASK); /* Start the timer */ cr = readl(base + TIMER_CR); cr |= TIMER_1_CR_ENABLE; cr |= TIMER_1_CR_INT; writel(cr, base + TIMER_CR); return 0; } /* Use TIMER1 as clock event */ static struct clock_event_device fttmr010_clockevent = { .name = "TIMER1", /* Reasonably fast and accurate clock event */ .rating = 300, .shift = 32, .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, .set_next_event = fttmr010_timer_set_next_event, .set_state_shutdown = fttmr010_timer_shutdown, .set_state_periodic = fttmr010_timer_set_periodic, .set_state_oneshot = fttmr010_timer_shutdown, .tick_resume = fttmr010_timer_shutdown, }; /* * IRQ handler for the timer */ static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = &fttmr010_clockevent; evt->event_handler(evt); return IRQ_HANDLED; } static struct irqaction fttmr010_timer_irq = { .name = "Faraday FTTMR010 Timer Tick", .flags = IRQF_TIMER, .handler = fttmr010_timer_interrupt, }; static int __init fttmr010_timer_init(struct device_node *np) { int irq; struct clk *clk; int ret; /* * These implementations require a clock reference. * FIXME: we currently only support clocking using PCLK * and using EXTCLK is not supported in the driver. */ clk = of_clk_get_by_name(np, "PCLK"); if (IS_ERR(clk)) { pr_err("could not get PCLK\n"); return PTR_ERR(clk); } ret = clk_prepare_enable(clk); if (ret) { pr_err("failed to enable PCLK\n"); return ret; } tick_rate = clk_get_rate(clk); base = of_iomap(np, 0); if (!base) { pr_err("Can't remap registers"); return -ENXIO; } /* IRQ for timer 1 */ irq = irq_of_parse_and_map(np, 0); if (irq <= 0) { pr_err("Can't parse IRQ"); return -EINVAL; } /* * Reset the interrupt mask and status */ writel(TIMER_INT_ALL_MASK, base + TIMER_INTR_MASK); writel(0, base + TIMER_INTR_STATE); writel(TIMER_DEFAULT_FLAGS, base + TIMER_CR); /* * Setup free-running clocksource timer (interrupts * disabled.) */ writel(0, base + TIMER3_COUNT); writel(0, base + TIMER3_LOAD); writel(0, base + TIMER3_MATCH1); writel(0, base + TIMER3_MATCH2); clocksource_mmio_init(base + TIMER3_COUNT, "fttmr010_clocksource", tick_rate, 300, 32, clocksource_mmio_readl_up); sched_clock_register(fttmr010_read_sched_clock, 32, tick_rate); /* * Setup clockevent timer (interrupt-driven.) */ writel(0, base + TIMER1_COUNT); writel(0, base + TIMER1_LOAD); writel(0, base + TIMER1_MATCH1); writel(0, base + TIMER1_MATCH2); setup_irq(irq, &fttmr010_timer_irq); fttmr010_clockevent.cpumask = cpumask_of(0); clockevents_config_and_register(&fttmr010_clockevent, tick_rate, 1, 0xffffffff); return 0; } CLOCKSOURCE_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init); CLOCKSOURCE_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init);