/* * Copyright (C) 2007-2009 ST-Ericsson AB * License terms: GNU General Public License (GPL) version 2 * Timer COH 901 328, runs the OS timer interrupt. * Author: Linus Walleij <linus.walleij@stericsson.com> */ #include <linux/interrupt.h> #include <linux/time.h> #include <linux/timex.h> #include <linux/clockchips.h> #include <linux/clocksource.h> #include <linux/types.h> #include <linux/io.h> #include <linux/clk.h> #include <linux/err.h> #include <linux/irq.h> #include <linux/delay.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/sched_clock.h> /* Generic stuff */ #include <asm/mach/map.h> #include <asm/mach/time.h> /* * APP side special timer registers * This timer contains four timers which can fire an interrupt each. * OS (operating system) timer @ 32768 Hz * DD (device driver) timer @ 1 kHz * GP1 (general purpose 1) timer @ 1MHz * GP2 (general purpose 2) timer @ 1MHz */ /* Reset OS Timer 32bit (-/W) */ #define U300_TIMER_APP_ROST (0x0000) #define U300_TIMER_APP_ROST_TIMER_RESET (0x00000000) /* Enable OS Timer 32bit (-/W) */ #define U300_TIMER_APP_EOST (0x0004) #define U300_TIMER_APP_EOST_TIMER_ENABLE (0x00000000) /* Disable OS Timer 32bit (-/W) */ #define U300_TIMER_APP_DOST (0x0008) #define U300_TIMER_APP_DOST_TIMER_DISABLE (0x00000000) /* OS Timer Mode Register 32bit (-/W) */ #define U300_TIMER_APP_SOSTM (0x000c) #define U300_TIMER_APP_SOSTM_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_SOSTM_MODE_ONE_SHOT (0x00000001) /* OS Timer Status Register 32bit (R/-) */ #define U300_TIMER_APP_OSTS (0x0010) #define U300_TIMER_APP_OSTS_TIMER_STATE_MASK (0x0000000F) #define U300_TIMER_APP_OSTS_TIMER_STATE_IDLE (0x00000001) #define U300_TIMER_APP_OSTS_TIMER_STATE_ACTIVE (0x00000002) #define U300_TIMER_APP_OSTS_ENABLE_IND (0x00000010) #define U300_TIMER_APP_OSTS_MODE_MASK (0x00000020) #define U300_TIMER_APP_OSTS_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_OSTS_MODE_ONE_SHOT (0x00000020) #define U300_TIMER_APP_OSTS_IRQ_ENABLED_IND (0x00000040) #define U300_TIMER_APP_OSTS_IRQ_PENDING_IND (0x00000080) /* OS Timer Current Count Register 32bit (R/-) */ #define U300_TIMER_APP_OSTCC (0x0014) /* OS Timer Terminal Count Register 32bit (R/W) */ #define U300_TIMER_APP_OSTTC (0x0018) /* OS Timer Interrupt Enable Register 32bit (-/W) */ #define U300_TIMER_APP_OSTIE (0x001c) #define U300_TIMER_APP_OSTIE_IRQ_DISABLE (0x00000000) #define U300_TIMER_APP_OSTIE_IRQ_ENABLE (0x00000001) /* OS Timer Interrupt Acknowledge Register 32bit (-/W) */ #define U300_TIMER_APP_OSTIA (0x0020) #define U300_TIMER_APP_OSTIA_IRQ_ACK (0x00000080) /* Reset DD Timer 32bit (-/W) */ #define U300_TIMER_APP_RDDT (0x0040) #define U300_TIMER_APP_RDDT_TIMER_RESET (0x00000000) /* Enable DD Timer 32bit (-/W) */ #define U300_TIMER_APP_EDDT (0x0044) #define U300_TIMER_APP_EDDT_TIMER_ENABLE (0x00000000) /* Disable DD Timer 32bit (-/W) */ #define U300_TIMER_APP_DDDT (0x0048) #define U300_TIMER_APP_DDDT_TIMER_DISABLE (0x00000000) /* DD Timer Mode Register 32bit (-/W) */ #define U300_TIMER_APP_SDDTM (0x004c) #define U300_TIMER_APP_SDDTM_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_SDDTM_MODE_ONE_SHOT (0x00000001) /* DD Timer Status Register 32bit (R/-) */ #define U300_TIMER_APP_DDTS (0x0050) #define U300_TIMER_APP_DDTS_TIMER_STATE_MASK (0x0000000F) #define U300_TIMER_APP_DDTS_TIMER_STATE_IDLE (0x00000001) #define U300_TIMER_APP_DDTS_TIMER_STATE_ACTIVE (0x00000002) #define U300_TIMER_APP_DDTS_ENABLE_IND (0x00000010) #define U300_TIMER_APP_DDTS_MODE_MASK (0x00000020) #define U300_TIMER_APP_DDTS_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_DDTS_MODE_ONE_SHOT (0x00000020) #define U300_TIMER_APP_DDTS_IRQ_ENABLED_IND (0x00000040) #define U300_TIMER_APP_DDTS_IRQ_PENDING_IND (0x00000080) /* DD Timer Current Count Register 32bit (R/-) */ #define U300_TIMER_APP_DDTCC (0x0054) /* DD Timer Terminal Count Register 32bit (R/W) */ #define U300_TIMER_APP_DDTTC (0x0058) /* DD Timer Interrupt Enable Register 32bit (-/W) */ #define U300_TIMER_APP_DDTIE (0x005c) #define U300_TIMER_APP_DDTIE_IRQ_DISABLE (0x00000000) #define U300_TIMER_APP_DDTIE_IRQ_ENABLE (0x00000001) /* DD Timer Interrupt Acknowledge Register 32bit (-/W) */ #define U300_TIMER_APP_DDTIA (0x0060) #define U300_TIMER_APP_DDTIA_IRQ_ACK (0x00000080) /* Reset GP1 Timer 32bit (-/W) */ #define U300_TIMER_APP_RGPT1 (0x0080) #define U300_TIMER_APP_RGPT1_TIMER_RESET (0x00000000) /* Enable GP1 Timer 32bit (-/W) */ #define U300_TIMER_APP_EGPT1 (0x0084) #define U300_TIMER_APP_EGPT1_TIMER_ENABLE (0x00000000) /* Disable GP1 Timer 32bit (-/W) */ #define U300_TIMER_APP_DGPT1 (0x0088) #define U300_TIMER_APP_DGPT1_TIMER_DISABLE (0x00000000) /* GP1 Timer Mode Register 32bit (-/W) */ #define U300_TIMER_APP_SGPT1M (0x008c) #define U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT (0x00000001) /* GP1 Timer Status Register 32bit (R/-) */ #define U300_TIMER_APP_GPT1S (0x0090) #define U300_TIMER_APP_GPT1S_TIMER_STATE_MASK (0x0000000F) #define U300_TIMER_APP_GPT1S_TIMER_STATE_IDLE (0x00000001) #define U300_TIMER_APP_GPT1S_TIMER_STATE_ACTIVE (0x00000002) #define U300_TIMER_APP_GPT1S_ENABLE_IND (0x00000010) #define U300_TIMER_APP_GPT1S_MODE_MASK (0x00000020) #define U300_TIMER_APP_GPT1S_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_GPT1S_MODE_ONE_SHOT (0x00000020) #define U300_TIMER_APP_GPT1S_IRQ_ENABLED_IND (0x00000040) #define U300_TIMER_APP_GPT1S_IRQ_PENDING_IND (0x00000080) /* GP1 Timer Current Count Register 32bit (R/-) */ #define U300_TIMER_APP_GPT1CC (0x0094) /* GP1 Timer Terminal Count Register 32bit (R/W) */ #define U300_TIMER_APP_GPT1TC (0x0098) /* GP1 Timer Interrupt Enable Register 32bit (-/W) */ #define U300_TIMER_APP_GPT1IE (0x009c) #define U300_TIMER_APP_GPT1IE_IRQ_DISABLE (0x00000000) #define U300_TIMER_APP_GPT1IE_IRQ_ENABLE (0x00000001) /* GP1 Timer Interrupt Acknowledge Register 32bit (-/W) */ #define U300_TIMER_APP_GPT1IA (0x00a0) #define U300_TIMER_APP_GPT1IA_IRQ_ACK (0x00000080) /* Reset GP2 Timer 32bit (-/W) */ #define U300_TIMER_APP_RGPT2 (0x00c0) #define U300_TIMER_APP_RGPT2_TIMER_RESET (0x00000000) /* Enable GP2 Timer 32bit (-/W) */ #define U300_TIMER_APP_EGPT2 (0x00c4) #define U300_TIMER_APP_EGPT2_TIMER_ENABLE (0x00000000) /* Disable GP2 Timer 32bit (-/W) */ #define U300_TIMER_APP_DGPT2 (0x00c8) #define U300_TIMER_APP_DGPT2_TIMER_DISABLE (0x00000000) /* GP2 Timer Mode Register 32bit (-/W) */ #define U300_TIMER_APP_SGPT2M (0x00cc) #define U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_SGPT2M_MODE_ONE_SHOT (0x00000001) /* GP2 Timer Status Register 32bit (R/-) */ #define U300_TIMER_APP_GPT2S (0x00d0) #define U300_TIMER_APP_GPT2S_TIMER_STATE_MASK (0x0000000F) #define U300_TIMER_APP_GPT2S_TIMER_STATE_IDLE (0x00000001) #define U300_TIMER_APP_GPT2S_TIMER_STATE_ACTIVE (0x00000002) #define U300_TIMER_APP_GPT2S_ENABLE_IND (0x00000010) #define U300_TIMER_APP_GPT2S_MODE_MASK (0x00000020) #define U300_TIMER_APP_GPT2S_MODE_CONTINUOUS (0x00000000) #define U300_TIMER_APP_GPT2S_MODE_ONE_SHOT (0x00000020) #define U300_TIMER_APP_GPT2S_IRQ_ENABLED_IND (0x00000040) #define U300_TIMER_APP_GPT2S_IRQ_PENDING_IND (0x00000080) /* GP2 Timer Current Count Register 32bit (R/-) */ #define U300_TIMER_APP_GPT2CC (0x00d4) /* GP2 Timer Terminal Count Register 32bit (R/W) */ #define U300_TIMER_APP_GPT2TC (0x00d8) /* GP2 Timer Interrupt Enable Register 32bit (-/W) */ #define U300_TIMER_APP_GPT2IE (0x00dc) #define U300_TIMER_APP_GPT2IE_IRQ_DISABLE (0x00000000) #define U300_TIMER_APP_GPT2IE_IRQ_ENABLE (0x00000001) /* GP2 Timer Interrupt Acknowledge Register 32bit (-/W) */ #define U300_TIMER_APP_GPT2IA (0x00e0) #define U300_TIMER_APP_GPT2IA_IRQ_ACK (0x00000080) /* Clock request control register - all four timers */ #define U300_TIMER_APP_CRC (0x100) #define U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE (0x00000001) static void __iomem *u300_timer_base; struct u300_clockevent_data { struct clock_event_device cevd; unsigned ticks_per_jiffy; }; static int u300_shutdown(struct clock_event_device *evt) { /* Disable interrupts on GP1 */ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Disable GP1 */ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, u300_timer_base + U300_TIMER_APP_DGPT1); return 0; } /* * If we have oneshot timer active, the oneshot scheduling function * u300_set_next_event() is called immediately after. */ static int u300_set_oneshot(struct clock_event_device *evt) { /* Just return; here? */ /* * The actual event will be programmed by the next event hook, * so we just set a dummy value somewhere at the end of the * universe here. */ /* Disable interrupts on GPT1 */ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Disable GP1 while we're reprogramming it. */ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, u300_timer_base + U300_TIMER_APP_DGPT1); /* * Expire far in the future, u300_set_next_event() will be * called soon... */ writel(0xFFFFFFFF, u300_timer_base + U300_TIMER_APP_GPT1TC); /* We run one shot per tick here! */ writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT, u300_timer_base + U300_TIMER_APP_SGPT1M); /* Enable interrupts for this timer */ writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Enable timer */ writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE, u300_timer_base + U300_TIMER_APP_EGPT1); return 0; } static int u300_set_periodic(struct clock_event_device *evt) { struct u300_clockevent_data *cevdata = container_of(evt, struct u300_clockevent_data, cevd); /* Disable interrupts on GPT1 */ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Disable GP1 while we're reprogramming it. */ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, u300_timer_base + U300_TIMER_APP_DGPT1); /* * Set the periodic mode to a certain number of ticks per * jiffy. */ writel(cevdata->ticks_per_jiffy, u300_timer_base + U300_TIMER_APP_GPT1TC); /* * Set continuous mode, so the timer keeps triggering * interrupts. */ writel(U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS, u300_timer_base + U300_TIMER_APP_SGPT1M); /* Enable timer interrupts */ writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Then enable the OS timer again */ writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE, u300_timer_base + U300_TIMER_APP_EGPT1); return 0; } /* * The app timer in one shot mode obviously has to be reprogrammed * in EXACTLY this sequence to work properly. Do NOT try to e.g. replace * the interrupt disable + timer disable commands with a reset command, * it will fail miserably. Apparently (and I found this the hard way) * the timer is very sensitive to the instruction order, though you don't * get that impression from the data sheet. */ static int u300_set_next_event(unsigned long cycles, struct clock_event_device *evt) { /* Disable interrupts on GPT1 */ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Disable GP1 while we're reprogramming it. */ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, u300_timer_base + U300_TIMER_APP_DGPT1); /* Reset the General Purpose timer 1. */ writel(U300_TIMER_APP_RGPT1_TIMER_RESET, u300_timer_base + U300_TIMER_APP_RGPT1); /* IRQ in n * cycles */ writel(cycles, u300_timer_base + U300_TIMER_APP_GPT1TC); /* * We run one shot per tick here! (This is necessary to reconfigure, * the timer will tilt if you don't!) */ writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT, u300_timer_base + U300_TIMER_APP_SGPT1M); /* Enable timer interrupts */ writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE, u300_timer_base + U300_TIMER_APP_GPT1IE); /* Then enable the OS timer again */ writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE, u300_timer_base + U300_TIMER_APP_EGPT1); return 0; } static struct u300_clockevent_data u300_clockevent_data = { /* Use general purpose timer 1 as clock event */ .cevd = { .name = "GPT1", /* Reasonably fast and accurate clock event */ .rating = 300, .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, .set_next_event = u300_set_next_event, .set_state_shutdown = u300_shutdown, .set_state_periodic = u300_set_periodic, .set_state_oneshot = u300_set_oneshot, }, }; /* Clock event timer interrupt handler */ static irqreturn_t u300_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = &u300_clockevent_data.cevd; /* ACK/Clear timer IRQ for the APP GPT1 Timer */ writel(U300_TIMER_APP_GPT1IA_IRQ_ACK, u300_timer_base + U300_TIMER_APP_GPT1IA); evt->event_handler(evt); return IRQ_HANDLED; } static struct irqaction u300_timer_irq = { .name = "U300 Timer Tick", .flags = IRQF_TIMER | IRQF_IRQPOLL, .handler = u300_timer_interrupt, }; /* * Override the global weak sched_clock symbol with this * local implementation which uses the clocksource to get some * better resolution when scheduling the kernel. We accept that * this wraps around for now, since it is just a relative time * stamp. (Inspired by OMAP implementation.) */ static u64 notrace u300_read_sched_clock(void) { return readl(u300_timer_base + U300_TIMER_APP_GPT2CC); } static unsigned long u300_read_current_timer(void) { return readl(u300_timer_base + U300_TIMER_APP_GPT2CC); } static struct delay_timer u300_delay_timer; /* * This sets up the system timers, clock source and clock event. */ static int __init u300_timer_init_of(struct device_node *np) { unsigned int irq; struct clk *clk; unsigned long rate; int ret; u300_timer_base = of_iomap(np, 0); if (!u300_timer_base) { pr_err("could not ioremap system timer\n"); return -ENXIO; } /* Get the IRQ for the GP1 timer */ irq = irq_of_parse_and_map(np, 2); if (!irq) { pr_err("no IRQ for system timer\n"); return -EINVAL; } pr_info("U300 GP1 timer @ base: %p, IRQ: %u\n", u300_timer_base, irq); /* Clock the interrupt controller */ clk = of_clk_get(np, 0); if (IS_ERR(clk)) return PTR_ERR(clk); ret = clk_prepare_enable(clk); if (ret) return ret; rate = clk_get_rate(clk); u300_clockevent_data.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ); sched_clock_register(u300_read_sched_clock, 32, rate); u300_delay_timer.read_current_timer = &u300_read_current_timer; u300_delay_timer.freq = rate; register_current_timer_delay(&u300_delay_timer); /* * Disable the "OS" and "DD" timers - these are designed for Symbian! * Example usage in cnh1601578 cpu subsystem pd_timer_app.c */ writel(U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE, u300_timer_base + U300_TIMER_APP_CRC); writel(U300_TIMER_APP_ROST_TIMER_RESET, u300_timer_base + U300_TIMER_APP_ROST); writel(U300_TIMER_APP_DOST_TIMER_DISABLE, u300_timer_base + U300_TIMER_APP_DOST); writel(U300_TIMER_APP_RDDT_TIMER_RESET, u300_timer_base + U300_TIMER_APP_RDDT); writel(U300_TIMER_APP_DDDT_TIMER_DISABLE, u300_timer_base + U300_TIMER_APP_DDDT); /* Reset the General Purpose timer 1. */ writel(U300_TIMER_APP_RGPT1_TIMER_RESET, u300_timer_base + U300_TIMER_APP_RGPT1); /* Set up the IRQ handler */ ret = setup_irq(irq, &u300_timer_irq); if (ret) return ret; /* Reset the General Purpose timer 2 */ writel(U300_TIMER_APP_RGPT2_TIMER_RESET, u300_timer_base + U300_TIMER_APP_RGPT2); /* Set this timer to run around forever */ writel(0xFFFFFFFFU, u300_timer_base + U300_TIMER_APP_GPT2TC); /* Set continuous mode so it wraps around */ writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS, u300_timer_base + U300_TIMER_APP_SGPT2M); /* Disable timer interrupts */ writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE, u300_timer_base + U300_TIMER_APP_GPT2IE); /* Then enable the GP2 timer to use as a free running us counter */ writel(U300_TIMER_APP_EGPT2_TIMER_ENABLE, u300_timer_base + U300_TIMER_APP_EGPT2); /* Use general purpose timer 2 as clock source */ ret = clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC, "GPT2", rate, 300, 32, clocksource_mmio_readl_up); if (ret) { pr_err("timer: failed to initialize U300 clock source\n"); return ret; } /* Configure and register the clockevent */ clockevents_config_and_register(&u300_clockevent_data.cevd, rate, 1, 0xffffffff); /* * TODO: init and register the rest of the timers too, they can be * used by hrtimers! */ return 0; } TIMER_OF_DECLARE(u300_timer, "stericsson,u300-apptimer", u300_timer_init_of);