diff options
Diffstat (limited to 'arch/arm/plat-samsung/samsung-time.c')
-rw-r--r-- | arch/arm/plat-samsung/samsung-time.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/samsung-time.c b/arch/arm/plat-samsung/samsung-time.c new file mode 100644 index 00000000000..aa8aa8014cc --- /dev/null +++ b/arch/arm/plat-samsung/samsung-time.c @@ -0,0 +1,394 @@ +/* + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * SAMSUNG - Common hr-timer support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/platform_device.h> + +#include <asm/smp_twd.h> +#include <asm/mach/time.h> +#include <asm/mach/arch.h> +#include <asm/mach/map.h> +#include <asm/sched_clock.h> + +#include <mach/map.h> +#include <plat/devs.h> +#include <plat/regs-timer.h> +#include <plat/samsung-time.h> + +static struct clk *tin_event; +static struct clk *tin_source; +static struct clk *tdiv_event; +static struct clk *tdiv_source; +static struct clk *timerclk; +static struct samsung_timer_source timer_source; +static unsigned long clock_count_per_tick; +static void samsung_timer_resume(void); + +static void samsung_time_stop(enum samsung_timer_mode mode) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + switch (mode) { + case SAMSUNG_PWM0: + tcon &= ~S3C2410_TCON_T0START; + break; + + case SAMSUNG_PWM1: + tcon &= ~S3C2410_TCON_T1START; + break; + + case SAMSUNG_PWM2: + tcon &= ~S3C2410_TCON_T2START; + break; + + case SAMSUNG_PWM3: + tcon &= ~S3C2410_TCON_T3START; + break; + + case SAMSUNG_PWM4: + tcon &= ~S3C2410_TCON_T4START; + break; + + default: + printk(KERN_ERR "Invalid Timer %d\n", mode); + break; + } + __raw_writel(tcon, S3C2410_TCON); +} + +static void samsung_time_setup(enum samsung_timer_mode mode, unsigned long tcnt) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + tcnt--; + + switch (mode) { + case SAMSUNG_PWM0: + tcon &= ~(0x0f << 0); + tcon |= S3C2410_TCON_T0MANUALUPD; + break; + + case SAMSUNG_PWM1: + tcon &= ~(0x0f << 8); + tcon |= S3C2410_TCON_T1MANUALUPD; + break; + + case SAMSUNG_PWM2: + tcon &= ~(0x0f << 12); + tcon |= S3C2410_TCON_T2MANUALUPD; + break; + + case SAMSUNG_PWM3: + tcon &= ~(0x0f << 16); + tcon |= S3C2410_TCON_T3MANUALUPD; + break; + + case SAMSUNG_PWM4: + tcon &= ~(0x07 << 20); + tcon |= S3C2410_TCON_T4MANUALUPD; + break; + + default: + printk(KERN_ERR "Invalid Timer %d\n", mode); + break; + } + + __raw_writel(tcnt, S3C2410_TCNTB(mode)); + __raw_writel(tcnt, S3C2410_TCMPB(mode)); + __raw_writel(tcon, S3C2410_TCON); +} + +static void samsung_time_start(enum samsung_timer_mode mode, bool periodic) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + switch (mode) { + case SAMSUNG_PWM0: + tcon |= S3C2410_TCON_T0START; + tcon &= ~S3C2410_TCON_T0MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T0RELOAD; + else + tcon &= ~S3C2410_TCON_T0RELOAD; + break; + + case SAMSUNG_PWM1: + tcon |= S3C2410_TCON_T1START; + tcon &= ~S3C2410_TCON_T1MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T1RELOAD; + else + tcon &= ~S3C2410_TCON_T1RELOAD; + break; + + case SAMSUNG_PWM2: + tcon |= S3C2410_TCON_T2START; + tcon &= ~S3C2410_TCON_T2MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T2RELOAD; + else + tcon &= ~S3C2410_TCON_T2RELOAD; + break; + + case SAMSUNG_PWM3: + tcon |= S3C2410_TCON_T3START; + tcon &= ~S3C2410_TCON_T3MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T3RELOAD; + else + tcon &= ~S3C2410_TCON_T3RELOAD; + break; + + case SAMSUNG_PWM4: + tcon |= S3C2410_TCON_T4START; + tcon &= ~S3C2410_TCON_T4MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T4RELOAD; + else + tcon &= ~S3C2410_TCON_T4RELOAD; + break; + + default: + printk(KERN_ERR "Invalid Timer %d\n", mode); + break; + } + __raw_writel(tcon, S3C2410_TCON); +} + +static int samsung_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + samsung_time_setup(timer_source.event_id, cycles); + samsung_time_start(timer_source.event_id, NON_PERIODIC); + + return 0; +} + +static void samsung_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + samsung_time_stop(timer_source.event_id); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + samsung_time_setup(timer_source.event_id, clock_count_per_tick); + samsung_time_start(timer_source.event_id, PERIODIC); + break; + + case CLOCK_EVT_MODE_ONESHOT: + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + break; + + case CLOCK_EVT_MODE_RESUME: + samsung_timer_resume(); + break; + } +} + +static void samsung_timer_resume(void) +{ + /* event timer restart */ + samsung_time_setup(timer_source.event_id, clock_count_per_tick); + samsung_time_start(timer_source.event_id, PERIODIC); + + /* source timer restart */ + samsung_time_setup(timer_source.source_id, TCNT_MAX); + samsung_time_start(timer_source.source_id, PERIODIC); +} + +void __init samsung_set_timer_source(enum samsung_timer_mode event, + enum samsung_timer_mode source) +{ + s3c_device_timer[event].dev.bus = &platform_bus_type; + s3c_device_timer[source].dev.bus = &platform_bus_type; + + timer_source.event_id = event; + timer_source.source_id = source; +} + +static struct clock_event_device time_event_device = { + .name = "samsung_event_timer", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 200, + .set_next_event = samsung_set_next_event, + .set_mode = samsung_set_mode, +}; + +static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction samsung_clock_event_irq = { + .name = "samsung_time_irq", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = samsung_clock_event_isr, + .dev_id = &time_event_device, +}; + +static void __init samsung_clockevent_init(void) +{ + unsigned long pclk; + unsigned long clock_rate; + unsigned int irq_number; + struct clk *tscaler; + + pclk = clk_get_rate(timerclk); + + tscaler = clk_get_parent(tdiv_event); + + clk_set_rate(tscaler, pclk / 2); + clk_set_rate(tdiv_event, pclk / 2); + clk_set_parent(tin_event, tdiv_event); + + clock_rate = clk_get_rate(tin_event); + clock_count_per_tick = clock_rate / HZ; + + time_event_device.cpumask = cpumask_of(0); + clockevents_config_and_register(&time_event_device, clock_rate, 1, -1); + + irq_number = timer_source.event_id + IRQ_TIMER0; + setup_irq(irq_number, &samsung_clock_event_irq); +} + +static void __iomem *samsung_timer_reg(void) +{ + unsigned long offset = 0; + + switch (timer_source.source_id) { + case SAMSUNG_PWM0: + case SAMSUNG_PWM1: + case SAMSUNG_PWM2: + case SAMSUNG_PWM3: + offset = (timer_source.source_id * 0x0c) + 0x14; + break; + + case SAMSUNG_PWM4: + offset = 0x40; + break; + + default: + printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id); + return NULL; + } + + return S3C_TIMERREG(offset); +} + +/* + * 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 U300 implementation.) + */ +static u32 notrace samsung_read_sched_clock(void) +{ + void __iomem *reg = samsung_timer_reg(); + + if (!reg) + return 0; + + return ~__raw_readl(reg); +} + +static void __init samsung_clocksource_init(void) +{ + unsigned long pclk; + unsigned long clock_rate; + + pclk = clk_get_rate(timerclk); + + clk_set_rate(tdiv_source, pclk / 2); + clk_set_parent(tin_source, tdiv_source); + + clock_rate = clk_get_rate(tin_source); + + samsung_time_setup(timer_source.source_id, TCNT_MAX); + samsung_time_start(timer_source.source_id, PERIODIC); + + setup_sched_clock(samsung_read_sched_clock, 32, clock_rate); + + if (clocksource_mmio_init(samsung_timer_reg(), "samsung_clocksource_timer", + clock_rate, 250, 32, clocksource_mmio_readl_down)) + panic("samsung_clocksource_timer: can't register clocksource\n"); +} + +static void __init samsung_timer_resources(void) +{ + + unsigned long event_id = timer_source.event_id; + unsigned long source_id = timer_source.source_id; + char devname[15]; + + timerclk = clk_get(NULL, "timers"); + if (IS_ERR(timerclk)) + panic("failed to get timers clock for timer"); + + clk_enable(timerclk); + + sprintf(devname, "s3c24xx-pwm.%lu", event_id); + s3c_device_timer[event_id].id = event_id; + s3c_device_timer[event_id].dev.init_name = devname; + + tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin"); + if (IS_ERR(tin_event)) + panic("failed to get pwm-tin clock for event timer"); + + tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv"); + if (IS_ERR(tdiv_event)) + panic("failed to get pwm-tdiv clock for event timer"); + + clk_enable(tin_event); + + sprintf(devname, "s3c24xx-pwm.%lu", source_id); + s3c_device_timer[source_id].id = source_id; + s3c_device_timer[source_id].dev.init_name = devname; + + tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin"); + if (IS_ERR(tin_source)) + panic("failed to get pwm-tin clock for source timer"); + + tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv"); + if (IS_ERR(tdiv_source)) + panic("failed to get pwm-tdiv clock for source timer"); + + clk_enable(tin_source); +} + +void __init samsung_timer_init(void) +{ + samsung_timer_resources(); + samsung_clockevent_init(); + samsung_clocksource_init(); +} |