| /* | 
 |  * Marvell Armada 370/XP SoC timer handling. | 
 |  * | 
 |  * Copyright (C) 2012 Marvell | 
 |  * | 
 |  * Lior Amsalem <[email protected]> | 
 |  * Gregory CLEMENT <[email protected]> | 
 |  * Thomas Petazzoni <[email protected]> | 
 |  * | 
 |  * This file is licensed under the terms of the GNU General Public | 
 |  * License version 2.  This program is licensed "as is" without any | 
 |  * warranty of any kind, whether express or implied. | 
 |  * | 
 |  * 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> | 
 | #include <linux/of.h> | 
 | #include <linux/of_irq.h> | 
 | #include <linux/of_address.h> | 
 | #include <linux/irq.h> | 
 | #include <linux/module.h> | 
 | #include <linux/sched_clock.h> | 
 | #include <linux/percpu.h> | 
 | #include <linux/syscore_ops.h> | 
 |  | 
 | /* | 
 |  * Timer block registers. | 
 |  */ | 
 | #define TIMER_CTRL_OFF		0x0000 | 
 | #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		 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) | 
 | #define  TIMER1_CLR_MASK         (~0x100) | 
 | #define TIMER0_RELOAD_OFF	0x0010 | 
 | #define TIMER0_VAL_OFF		0x0014 | 
 | #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 | 
 | #define TIMER_DIVIDER           (1 << TIMER_DIVIDER_SHIFT) | 
 |  | 
 | /* | 
 |  * SoC-specific data. | 
 |  */ | 
 | 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 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); | 
 | } | 
 |  | 
 | /* | 
 |  * Clockevent handling. | 
 |  */ | 
 | static int | 
 | armada_370_xp_clkevt_next_event(unsigned long delta, | 
 | 				struct clock_event_device *dev) | 
 | { | 
 | 	/* | 
 | 	 * Clear clockevent timer interrupt. | 
 | 	 */ | 
 | 	writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); | 
 |  | 
 | 	/* | 
 | 	 * Setup new clockevent timer value. | 
 | 	 */ | 
 | 	writel(delta, local_base + TIMER0_VAL_OFF); | 
 |  | 
 | 	/* | 
 | 	 * Enable the timer. | 
 | 	 */ | 
 | 	local_timer_ctrl_clrset(TIMER0_RELOAD_EN, enable_mask); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static void | 
 | armada_370_xp_clkevt_mode(enum clock_event_mode mode, | 
 | 			  struct clock_event_device *dev) | 
 | { | 
 | 	if (mode == CLOCK_EVT_MODE_PERIODIC) { | 
 |  | 
 | 		/* | 
 | 		 * Setup timer to fire at 1/HZ intervals. | 
 | 		 */ | 
 | 		writel(ticks_per_jiffy - 1, local_base + TIMER0_RELOAD_OFF); | 
 | 		writel(ticks_per_jiffy - 1, local_base + TIMER0_VAL_OFF); | 
 |  | 
 | 		/* | 
 | 		 * Enable timer. | 
 | 		 */ | 
 | 		local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask); | 
 | 	} else { | 
 | 		/* | 
 | 		 * Disable timer. | 
 | 		 */ | 
 | 		local_timer_ctrl_clrset(TIMER0_EN, 0); | 
 |  | 
 | 		/* | 
 | 		 * ACK pending timer interrupt. | 
 | 		 */ | 
 | 		writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); | 
 | 	} | 
 | } | 
 |  | 
 | 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(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); | 
 | 	evt->event_handler(evt); | 
 |  | 
 | 	return IRQ_HANDLED; | 
 | } | 
 |  | 
 | /* | 
 |  * 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, | 
 | }; | 
 |  | 
 | static u32 timer0_ctrl_reg, timer0_local_ctrl_reg; | 
 |  | 
 | static int armada_370_xp_timer_suspend(void) | 
 | { | 
 | 	timer0_ctrl_reg = readl(timer_base + TIMER_CTRL_OFF); | 
 | 	timer0_local_ctrl_reg = readl(local_base + TIMER_CTRL_OFF); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static void armada_370_xp_timer_resume(void) | 
 | { | 
 | 	writel(0xffffffff, timer_base + TIMER0_VAL_OFF); | 
 | 	writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF); | 
 | 	writel(timer0_ctrl_reg, timer_base + TIMER_CTRL_OFF); | 
 | 	writel(timer0_local_ctrl_reg, local_base + TIMER_CTRL_OFF); | 
 | } | 
 |  | 
 | struct syscore_ops armada_370_xp_timer_syscore_ops = { | 
 | 	.suspend	= armada_370_xp_timer_suspend, | 
 | 	.resume		= armada_370_xp_timer_resume, | 
 | }; | 
 |  | 
 | static void __init armada_370_xp_timer_common_init(struct device_node *np) | 
 | { | 
 | 	u32 clr = 0, set = 0; | 
 | 	int res; | 
 |  | 
 | 	timer_base = of_iomap(np, 0); | 
 | 	WARN_ON(!timer_base); | 
 | 	local_base = of_iomap(np, 1); | 
 |  | 
 | 	if (timer25Mhz) { | 
 | 		set = TIMER0_25MHZ;		 | 
 | 		enable_mask = TIMER0_EN; | 
 | 	} else { | 
 | 		clr = TIMER0_25MHZ; | 
 | 		enable_mask = TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT); | 
 | 	} | 
 | 	atomic_io_modify(timer_base + TIMER_CTRL_OFF, clr | set, set); | 
 | 	local_timer_ctrl_clrset(clr, set); | 
 |  | 
 | 	/* | 
 | 	 * We use timer 0 as clocksource, and private(local) timer 0 | 
 | 	 * for clockevents | 
 | 	 */ | 
 | 	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 | 
 | 	 * disabled). | 
 | 	 */ | 
 | 	writel(0xffffffff, timer_base + TIMER0_VAL_OFF); | 
 | 	writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF); | 
 |  | 
 | 	atomic_io_modify(timer_base + TIMER_CTRL_OFF, | 
 | 		TIMER0_RELOAD_EN | enable_mask, | 
 | 		TIMER0_RELOAD_EN | enable_mask); | 
 |  | 
 | 	/* | 
 | 	 * 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). | 
 | 	 */ | 
 | 	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)); | 
 |  | 
 | 	register_syscore_ops(&armada_370_xp_timer_syscore_ops); | 
 | } | 
 |  | 
 | 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)); | 
 | 	clk_prepare_enable(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_375_timer_init(struct device_node *np) | 
 | { | 
 | 	struct clk *clk; | 
 |  | 
 | 	clk = of_clk_get_by_name(np, "fixed"); | 
 | 	if (!IS_ERR(clk)) { | 
 | 		clk_prepare_enable(clk); | 
 | 		timer_clk = clk_get_rate(clk); | 
 | 	} else { | 
 |  | 
 | 		/* | 
 | 		 * This fallback is required in order to retain proper | 
 | 		 * devicetree backwards compatibility. | 
 | 		 */ | 
 | 		clk = of_clk_get(np, 0); | 
 |  | 
 | 		/* Must have at least a clock */ | 
 | 		BUG_ON(IS_ERR(clk)); | 
 | 		clk_prepare_enable(clk); | 
 | 		timer_clk = clk_get_rate(clk) / TIMER_DIVIDER; | 
 | 		timer25Mhz = false; | 
 | 	} | 
 |  | 
 | 	armada_370_xp_timer_common_init(np); | 
 | } | 
 | CLOCKSOURCE_OF_DECLARE(armada_375, "marvell,armada-375-timer", | 
 | 		       armada_375_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)); | 
 | 	clk_prepare_enable(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); |