diff options
Diffstat (limited to 'arch/arm/mach-u300/timer.c')
| -rw-r--r-- | arch/arm/mach-u300/timer.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/arch/arm/mach-u300/timer.c b/arch/arm/mach-u300/timer.c new file mode 100644 index 0000000..cce5320 --- /dev/null +++ b/arch/arm/mach-u300/timer.c @@ -0,0 +1,422 @@ +/* + * + * arch/arm/mach-u300/timer.c + * + * + * 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 <mach/hardware.h> + +/* Generic stuff */ +#include <asm/mach/map.h> +#include <asm/mach/time.h> +#include <asm/mach/irq.h> + +#include "clock.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) + +#define TICKS_PER_JIFFY ((CLOCK_TICK_RATE + (HZ/2)) / HZ) +#define US_PER_TICK ((1000000 + (HZ/2)) / HZ) + +/* + * The u300_set_mode() function is always called first, if we + * have oneshot timer active, the oneshot scheduling function + * u300_set_next_event() is called immediately after. + */ +static void u300_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* Disable interrupts on GPT1 */ + writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Disable GP1 while we're reprogramming it. */ + writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1); + /* + * Set the periodic mode to a certain number of ticks per + * jiffy. + */ + writel(TICKS_PER_JIFFY, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC); + /* + * Set continuous mode, so the timer keeps triggering + * interrupts. + */ + writel(U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS, + U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M); + /* Enable timer interrupts */ + writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Then enable the OS timer again */ + writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* Just break; 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_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Disable GP1 while we're reprogramming it. */ + writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1); + /* + * Expire far in the future, u300_set_next_event() will be + * called soon... + */ + writel(0xFFFFFFFF, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC); + /* We run one shot per tick here! */ + writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT, + U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M); + /* Enable interrupts for this timer */ + writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Enable timer */ + writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + /* Disable interrupts on GP1 */ + writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Disable GP1 */ + writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1); + break; + case CLOCK_EVT_MODE_RESUME: + /* Ignore this call */ + break; + } +} + +/* + * 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_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Disable GP1 while we're reprogramming it. */ + writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1); + /* Reset the General Purpose timer 1. */ + writel(U300_TIMER_APP_RGPT1_TIMER_RESET, + U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT1); + /* IRQ in n * cycles */ + writel(cycles, U300_TIMER_APP_VBASE + 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_APP_VBASE + U300_TIMER_APP_SGPT1M); + /* Enable timer interrupts */ + writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE); + /* Then enable the OS timer again */ + writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1); + return 0; +} + + +/* Use general purpose timer 1 as clock event */ +static struct clock_event_device clockevent_u300_1mhz = { + .name = "GPT1", + .rating = 300, /* Reasonably fast and accurate clock event */ + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + /* 22 calculated using the algorithm in arch/mips/kernel/time.c */ + .shift = 22, + .set_next_event = u300_set_next_event, + .set_mode = u300_set_mode, +}; + +/* Clock event timer interrupt handler */ +static irqreturn_t u300_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &clockevent_u300_1mhz; + /* ACK/Clear timer IRQ for the APP GPT1 Timer */ + writel(U300_TIMER_APP_GPT1IA_IRQ_ACK, + U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IA); + evt->event_handler(evt); + return IRQ_HANDLED; +} + +static struct irqaction u300_timer_irq = { + .name = "U300 Timer Tick", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = u300_timer_interrupt, +}; + +/* Use general purpose timer 2 as clock source */ +static cycle_t u300_get_cycles(struct clocksource *cs) +{ + return (cycles_t) readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC); +} + +static struct clocksource clocksource_u300_1mhz = { + .name = "GPT2", + .rating = 300, /* Reasonably fast and accurate clock source */ + .read = u300_get_cycles, + .mask = CLOCKSOURCE_MASK(32), /* 32 bits */ + /* 22 calculated using the algorithm in arch/mips/kernel/time.c */ + .shift = 22, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + + +/* + * This sets up the system timers, clock source and clock event. + */ +static void __init u300_timer_init(void) +{ + u300_enable_timer_clock(); + /* + * 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_APP_VBASE + U300_TIMER_APP_CRC); + writel(U300_TIMER_APP_ROST_TIMER_RESET, + U300_TIMER_APP_VBASE + U300_TIMER_APP_ROST); + writel(U300_TIMER_APP_DOST_TIMER_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_DOST); + writel(U300_TIMER_APP_RDDT_TIMER_RESET, + U300_TIMER_APP_VBASE + U300_TIMER_APP_RDDT); + writel(U300_TIMER_APP_DDDT_TIMER_DISABLE, + U300_TIMER_APP_VBASE + U300_TIMER_APP_DDDT); + + /* Reset the General Purpose timer 1. */ + writel(U300_TIMER_APP_RGPT1_TIMER_RESET, + U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT1); + + /* Set up the IRQ handler */ + setup_irq(IRQ_U300_TIMER_APP_GP1, &u300_timer_irq); + + /* Reset the General Purpose timer 2 */ + writel(U300_TIMER_APP_RGPT2_TIMER_RESET, + U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT2); + /* Set this timer to run around forever */ + writel(0xFFFFFFFFU, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2TC); + /* Set continuous mode so it wraps around */ + writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS, + U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT2M); + /* Disable timer interrupts */ + writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE, + U300_TIMER_APP_VBASE + 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_APP_VBASE + U300_TIMER_APP_EGPT2); + + /* This is a pure microsecond clock source */ + clocksource_u300_1mhz.mult = + clocksource_khz2mult(1000, clocksource_u300_1mhz.shift); + if (clocksource_register(&clocksource_u300_1mhz)) + printk(KERN_ERR "timer: failed to initialize clock " + "source %s\n", clocksource_u300_1mhz.name); + + clockevent_u300_1mhz.mult = + div_sc(1000000, NSEC_PER_SEC, clockevent_u300_1mhz.shift); + /* 32bit counter, so 32bits delta is max */ + clockevent_u300_1mhz.max_delta_ns = + clockevent_delta2ns(0xffffffff, &clockevent_u300_1mhz); + /* This timer is slow enough to set for 1 cycle == 1 MHz */ + clockevent_u300_1mhz.min_delta_ns = + clockevent_delta2ns(1, &clockevent_u300_1mhz); + clockevent_u300_1mhz.cpumask = cpumask_of(0); + clockevents_register_device(&clockevent_u300_1mhz); + /* + * TODO: init and register the rest of the timers too, they can be + * used by hrtimers! + */ +} + +/* + * Very simple system timer that only register the clock event and + * clock source. + */ +struct sys_timer u300_timer = { + .init = u300_timer_init, +}; |