| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Faraday Technology FTTMR010 timer driver |
| * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> |
| * |
| * Based on a rewrite of arch/arm/mach-gemini/timer.c: |
| * Copyright (C) 2001-2006 Storlink, Corp. |
| * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt> |
| */ |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/of.h> |
| #include <linux/of_address.h> |
| #include <linux/of_irq.h> |
| #include <linux/clockchips.h> |
| #include <linux/clocksource.h> |
| #include <linux/sched_clock.h> |
| #include <linux/clk.h> |
| #include <linux/slab.h> |
| #include <linux/bitops.h> |
| #include <linux/delay.h> |
| |
| /* |
| * 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; |
| #ifdef CONFIG_ARM |
| struct delay_timer delay_timer; |
| #endif |
| }; |
| |
| /* |
| * A local singleton used by sched_clock and delay timer reads, which are |
| * fast and 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 unsigned long fttmr010_read_current_timer_up(void) |
| { |
| return readl(local_fttmr->base + TIMER2_COUNT); |
| } |
| |
| static unsigned long fttmr010_read_current_timer_down(void) |
| { |
| return ~readl(local_fttmr->base + TIMER2_COUNT); |
| } |
| |
| static u64 notrace fttmr010_read_sched_clock_up(void) |
| { |
| return fttmr010_read_current_timer_up(); |
| } |
| |
| static u64 notrace fttmr010_read_sched_clock_down(void) |
| { |
| return fttmr010_read_current_timer_down(); |
| } |
| |
| 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); |
| |
| if (fttmr010->count_down) { |
| /* |
| * ASPEED Timer Controller will load TIMER1_LOAD register |
| * into TIMER1_COUNT register when the timer is re-enabled. |
| */ |
| writel(cycles, fttmr010->base + TIMER1_LOAD); |
| } else { |
| /* Setup the match register forward in time */ |
| cr = readl(fttmr010->base + TIMER1_COUNT); |
| writel(cr + cycles, 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_common_init(struct device_node *np, bool is_aspeed) |
| { |
| struct fttmr010 *fttmr010; |
| 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. |
| */ |
| if (is_aspeed) { |
| 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_aspeed) |
| 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); |
| sched_clock_register(fttmr010_read_sched_clock_down, 32, |
| fttmr010->tick_rate); |
| } 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_up, 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); |
| |
| #ifdef CONFIG_ARM |
| /* Also use this timer for delays */ |
| if (fttmr010->count_down) |
| fttmr010->delay_timer.read_current_timer = |
| fttmr010_read_current_timer_down; |
| else |
| fttmr010->delay_timer.read_current_timer = |
| fttmr010_read_current_timer_up; |
| fttmr010->delay_timer.freq = fttmr010->tick_rate; |
| register_current_timer_delay(&fttmr010->delay_timer); |
| #endif |
| |
| return 0; |
| |
| out_unmap: |
| iounmap(fttmr010->base); |
| out_free: |
| kfree(fttmr010); |
| out_disable_clock: |
| clk_disable_unprepare(clk); |
| |
| return ret; |
| } |
| |
| static __init int aspeed_timer_init(struct device_node *np) |
| { |
| return fttmr010_common_init(np, true); |
| } |
| |
| static __init int fttmr010_timer_init(struct device_node *np) |
| { |
| return fttmr010_common_init(np, false); |
| } |
| |
| TIMER_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init); |
| TIMER_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init); |
| TIMER_OF_DECLARE(moxart, "moxa,moxart-timer", fttmr010_timer_init); |
| TIMER_OF_DECLARE(ast2400, "aspeed,ast2400-timer", aspeed_timer_init); |
| TIMER_OF_DECLARE(ast2500, "aspeed,ast2500-timer", aspeed_timer_init); |