/* * 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 #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 BIT(0) #define TIMER_1_CR_CLOCK BIT(1) #define TIMER_1_CR_INT BIT(2) #define TIMER_2_CR_ENABLE BIT(3) #define TIMER_2_CR_CLOCK BIT(4) #define TIMER_2_CR_INT BIT(5) #define TIMER_3_CR_ENABLE BIT(6) #define TIMER_3_CR_CLOCK BIT(7) #define TIMER_3_CR_INT BIT(8) #define TIMER_1_CR_UPDOWN BIT(9) #define TIMER_2_CR_UPDOWN BIT(10) #define TIMER_3_CR_UPDOWN BIT(11) /* * The Aspeed AST2400 moves bits around in the control register * and lacks bits for setting the timer to count upwards. */ #define TIMER_1_CR_ASPEED_ENABLE BIT(0) #define TIMER_1_CR_ASPEED_CLOCK BIT(1) #define TIMER_1_CR_ASPEED_INT BIT(2) #define TIMER_2_CR_ASPEED_ENABLE BIT(4) #define TIMER_2_CR_ASPEED_CLOCK BIT(5) #define TIMER_2_CR_ASPEED_INT BIT(6) #define TIMER_3_CR_ASPEED_ENABLE BIT(8) #define TIMER_3_CR_ASPEED_CLOCK BIT(9) #define TIMER_3_CR_ASPEED_INT BIT(10) #define TIMER_1_INT_MATCH1 BIT(0) #define TIMER_1_INT_MATCH2 BIT(1) #define TIMER_1_INT_OVERFLOW BIT(2) #define TIMER_2_INT_MATCH1 BIT(3) #define TIMER_2_INT_MATCH2 BIT(4) #define TIMER_2_INT_OVERFLOW BIT(5) #define TIMER_3_INT_MATCH1 BIT(6) #define TIMER_3_INT_MATCH2 BIT(7) #define TIMER_3_INT_OVERFLOW BIT(8) #define TIMER_INT_ALL_MASK 0x1ff struct fttmr010 { void __iomem *base; unsigned int tick_rate; bool count_down; u32 t1_enable_val; struct clock_event_device clkevt; }; /* A local singleton used by sched_clock, which is stateless */ static struct fttmr010 *local_fttmr; static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt) { return container_of(evt, struct fttmr010, clkevt); } static u64 notrace fttmr010_read_sched_clock(void) { if (local_fttmr->count_down) return ~readl(local_fttmr->base + TIMER2_COUNT); return readl(local_fttmr->base + TIMER2_COUNT); } static int fttmr010_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { struct fttmr010 *fttmr010 = to_fttmr010(evt); u32 cr; /* Stop */ cr = readl(fttmr010->base + TIMER_CR); cr &= ~fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR); /* Setup the match register forward/backward in time */ cr = readl(fttmr010->base + TIMER1_COUNT); if (fttmr010->count_down) cr -= cycles; else cr += cycles; writel(cr, fttmr010->base + TIMER1_MATCH1); /* Start */ cr = readl(fttmr010->base + TIMER_CR); cr |= fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR); return 0; } static int fttmr010_timer_shutdown(struct clock_event_device *evt) { struct fttmr010 *fttmr010 = to_fttmr010(evt); u32 cr; /* Stop */ cr = readl(fttmr010->base + TIMER_CR); cr &= ~fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR); return 0; } static int fttmr010_timer_set_oneshot(struct clock_event_device *evt) { struct fttmr010 *fttmr010 = to_fttmr010(evt); u32 cr; /* Stop */ cr = readl(fttmr010->base + TIMER_CR); cr &= ~fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR); /* Setup counter start from 0 or ~0 */ writel(0, fttmr010->base + TIMER1_COUNT); if (fttmr010->count_down) writel(~0, fttmr010->base + TIMER1_LOAD); else writel(0, fttmr010->base + TIMER1_LOAD); /* Enable interrupt */ cr = readl(fttmr010->base + TIMER_INTR_MASK); cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); cr |= TIMER_1_INT_MATCH1; writel(cr, fttmr010->base + TIMER_INTR_MASK); return 0; } static int fttmr010_timer_set_periodic(struct clock_event_device *evt) { struct fttmr010 *fttmr010 = to_fttmr010(evt); u32 period = DIV_ROUND_CLOSEST(fttmr010->tick_rate, HZ); u32 cr; /* Stop */ cr = readl(fttmr010->base + TIMER_CR); cr &= ~fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR); /* Setup timer to fire at 1/HZ intervals. */ if (fttmr010->count_down) { writel(period, fttmr010->base + TIMER1_LOAD); writel(0, fttmr010->base + TIMER1_MATCH1); } else { cr = 0xffffffff - (period - 1); writel(cr, fttmr010->base + TIMER1_COUNT); writel(cr, fttmr010->base + TIMER1_LOAD); /* Enable interrupt on overflow */ cr = readl(fttmr010->base + TIMER_INTR_MASK); cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2); cr |= TIMER_1_INT_OVERFLOW; writel(cr, fttmr010->base + TIMER_INTR_MASK); } /* Start the timer */ cr = readl(fttmr010->base + TIMER_CR); cr |= fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR); return 0; } /* * IRQ handler for the timer */ static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; evt->event_handler(evt); return IRQ_HANDLED; } static int __init fttmr010_timer_init(struct device_node *np) { struct fttmr010 *fttmr010; bool is_ast2400; int irq; struct clk *clk; int ret; u32 val; /* * 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; } fttmr010 = kzalloc(sizeof(*fttmr010), GFP_KERNEL); if (!fttmr010) { ret = -ENOMEM; goto out_disable_clock; } fttmr010->tick_rate = clk_get_rate(clk); fttmr010->base = of_iomap(np, 0); if (!fttmr010->base) { pr_err("Can't remap registers"); ret = -ENXIO; goto out_free; } /* IRQ for timer 1 */ irq = irq_of_parse_and_map(np, 0); if (irq <= 0) { pr_err("Can't parse IRQ"); ret = -EINVAL; goto out_unmap; } /* * The Aspeed AST2400 moves bits around in the control register, * otherwise it works the same. */ is_ast2400 = of_device_is_compatible(np, "aspeed,ast2400-timer"); if (is_ast2400) { fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE | TIMER_1_CR_ASPEED_INT; /* Downward not available */ fttmr010->count_down = true; } else { fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT; } /* * Reset the interrupt mask and status */ writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK); writel(0, fttmr010->base + TIMER_INTR_STATE); /* * Enable timer 1 count up, timer 2 count up, except on Aspeed, * where everything just counts down. */ if (is_ast2400) val = TIMER_2_CR_ASPEED_ENABLE; else { val = TIMER_2_CR_ENABLE; if (!fttmr010->count_down) val |= TIMER_1_CR_UPDOWN | TIMER_2_CR_UPDOWN; } writel(val, fttmr010->base + TIMER_CR); /* * Setup free-running clocksource timer (interrupts * disabled.) */ local_fttmr = fttmr010; writel(0, fttmr010->base + TIMER2_COUNT); writel(0, fttmr010->base + TIMER2_MATCH1); writel(0, fttmr010->base + TIMER2_MATCH2); if (fttmr010->count_down) { writel(~0, fttmr010->base + TIMER2_LOAD); clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, "FTTMR010-TIMER2", fttmr010->tick_rate, 300, 32, clocksource_mmio_readl_down); } else { writel(0, fttmr010->base + TIMER2_LOAD); clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, "FTTMR010-TIMER2", fttmr010->tick_rate, 300, 32, clocksource_mmio_readl_up); } sched_clock_register(fttmr010_read_sched_clock, 32, fttmr010->tick_rate); /* * Setup clockevent timer (interrupt-driven) on timer 1. */ writel(0, fttmr010->base + TIMER1_COUNT); writel(0, fttmr010->base + TIMER1_LOAD); writel(0, fttmr010->base + TIMER1_MATCH1); writel(0, fttmr010->base + TIMER1_MATCH2); ret = request_irq(irq, fttmr010_timer_interrupt, IRQF_TIMER, "FTTMR010-TIMER1", &fttmr010->clkevt); if (ret) { pr_err("FTTMR010-TIMER1 no IRQ\n"); goto out_unmap; } fttmr010->clkevt.name = "FTTMR010-TIMER1"; /* Reasonably fast and accurate clock event */ fttmr010->clkevt.rating = 300; fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event; fttmr010->clkevt.set_state_shutdown = fttmr010_timer_shutdown; fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic; fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot; fttmr010->clkevt.tick_resume = fttmr010_timer_shutdown; fttmr010->clkevt.cpumask = cpumask_of(0); fttmr010->clkevt.irq = irq; clockevents_config_and_register(&fttmr010->clkevt, fttmr010->tick_rate, 1, 0xffffffff); return 0; out_unmap: iounmap(fttmr010->base); out_free: kfree(fttmr010); out_disable_clock: clk_disable_unprepare(clk); return ret; } CLOCKSOURCE_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init); CLOCKSOURCE_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init); CLOCKSOURCE_OF_DECLARE(moxart, "moxa,moxart-timer", fttmr010_timer_init); CLOCKSOURCE_OF_DECLARE(aspeed, "aspeed,ast2400-timer", fttmr010_timer_init);