diff options
Diffstat (limited to 'arch/arm/plat-mxs/timer-match.c')
| -rw-r--r-- | arch/arm/plat-mxs/timer-match.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/arm/plat-mxs/timer-match.c b/arch/arm/plat-mxs/timer-match.c new file mode 100644 index 000000000000..d6429e6955e6 --- /dev/null +++ b/arch/arm/plat-mxs/timer-match.c @@ -0,0 +1,164 @@ +/* + * System timer for Freescale i.MXS + * + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/irq.h> +#include <linux/interrupt.h> + +#include <asm/mach/time.h> + +#include <mach/device.h> +#include <mach/regs-timrot.h> + +static struct mxs_sys_timer *online_timer; + +static irqreturn_t mxs_timer_handler(int irq, void *dev_id); + +static cycle_t mxs_get_cycles(struct clocksource *cs) +{ + return ~__raw_readl(online_timer->base + + HW_TIMROT_RUNNING_COUNTn(online_timer->id)); +} + +static int mxs_set_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + unsigned int match; + match = __raw_readl(online_timer->base + + HW_TIMROT_RUNNING_COUNTn(online_timer->id)) - delta; + __raw_writel(match, online_timer->base + + HW_TIMROT_MATCH_COUNTn(online_timer->id)); + return (int)(match - + __raw_readl(online_timer->base + + HW_TIMROT_RUNNING_COUNTn(online_timer->id))) + > 0 ? -ETIME : 0; +} + + +static void mxs_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_SHUTDOWN: + __raw_writel(BM_TIMROT_TIMCTRLn_IRQ_EN | BM_TIMROT_TIMCTRLn_IRQ, + online_timer->base + HW_TIMROT_TIMCTRLn_CLR(0)); + break; + case CLOCK_EVT_MODE_RESUME: + case CLOCK_EVT_MODE_ONESHOT: + __raw_writel(BM_TIMROT_ROTCTRL_SFTRST | BM_TIMROT_ROTCTRL_CLKGATE, + online_timer->base + HW_TIMROT_ROTCTRL_CLR); + __raw_writel(BF_TIMROT_TIMCTRLn_SELECT(online_timer->clk_sel) | + BM_TIMROT_TIMCTRLn_IRQ_EN | + BM_TIMROT_TIMCTRLn_MATCH_MODE, + online_timer->base + HW_TIMROT_TIMCTRLn(online_timer->id)); + break; + default: + break; + } +} + +static struct clock_event_device mxs_clockevent = { + .name = "mxs tick timer ", + .features = CLOCK_EVT_FEAT_ONESHOT, + .shift = 32, + .set_next_event = mxs_set_next_event, + .set_mode = mxs_set_mode, + .rating = 200, +}; + +static struct clocksource mxs_clocksource = { + .name = "mxs clock source", + .rating = 250, + .read = mxs_get_cycles, + .mask = CLOCKSOURCE_MASK(32), + .shift = 10, + .flags = CLOCK_SOURCE_IS_CONTINUOUS +}; + +static struct irqaction mxs_timer_irq = { + .name = "i.MX/mxs Timer Tick", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = mxs_timer_handler, + .dev_id = &mxs_clockevent, +}; + +static int __init mxs_clocksource_init(struct clk *timer_clk) +{ + unsigned int c = clk_get_rate(timer_clk); + + mxs_clocksource.mult = clocksource_hz2mult(c, mxs_clocksource.shift); + clocksource_register(&mxs_clocksource); + return 0; +} + +static int __init mxs_clockevent_init(struct clk *timer_clk) +{ + unsigned int c = clk_get_rate(timer_clk); + + mxs_clockevent.mult = div_sc(c, NSEC_PER_SEC, mxs_clockevent.shift); + mxs_clockevent.min_delta_ns = clockevent_delta2ns(0xF, &mxs_clockevent); + mxs_clockevent.max_delta_ns = clockevent_delta2ns(0xFFFFFFF0, + &mxs_clockevent); + mxs_clockevent.cpumask = cpumask_of(0); + + clockevents_register_device(&mxs_clockevent); + return 0; +} + +static irqreturn_t mxs_timer_handler(int irq, void *dev_id) +{ + struct clock_event_device *c = dev_id; + if (__raw_readl(online_timer->base + + HW_TIMROT_TIMCTRLn(online_timer->id)) & + BM_TIMROT_TIMCTRLn_IRQ) { + __raw_writel(BM_TIMROT_TIMCTRLn_IRQ, + online_timer->base + + HW_TIMROT_TIMCTRLn_CLR(online_timer->id)); + c->event_handler(c); + } + return IRQ_HANDLED; +} + +void mxs_timer_init(struct mxs_sys_timer *timer) +{ + if (!timer->base || !timer->clk || IS_ERR(timer->clk)) + return; + if (online_timer) + return; + online_timer = timer; + clk_enable(online_timer->clk); + __raw_writel(BF_TIMROT_TIMCTRLn_SELECT(online_timer->clk_sel) | + BM_TIMROT_TIMCTRLn_IRQ_EN | + BM_TIMROT_TIMCTRLn_MATCH_MODE, + online_timer->base + HW_TIMROT_TIMCTRLn(online_timer->id)); + mxs_clocksource_init(online_timer->clk); + mxs_clockevent_init(online_timer->clk); + setup_irq(online_timer->irq, &mxs_timer_irq); +} + + |