/* * 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); 	/* 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_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);