diff options
Diffstat (limited to 'arch/mips/kernel/cevt-ds1287.c')
| -rw-r--r-- | arch/mips/kernel/cevt-ds1287.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/mips/kernel/cevt-ds1287.c b/arch/mips/kernel/cevt-ds1287.c new file mode 100644 index 000000000..61ad9079f --- /dev/null +++ b/arch/mips/kernel/cevt-ds1287.c @@ -0,0 +1,139 @@ +/* + * DS1287 clockevent driver + * + * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> + * + * 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/clockchips.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/mc146818rtc.h> +#include <linux/irq.h> + +#include <asm/time.h> + +int ds1287_timer_state(void) +{ + return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0; +} + +int ds1287_set_base_clock(unsigned int hz) +{ + u8 rate; + + switch (hz) { + case 128: + rate = 0x9; + break; + case 256: + rate = 0x8; + break; + case 1024: + rate = 0x6; + break; + default: + return -EINVAL; + } + + CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A); + + return 0; +} + +static int ds1287_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + return -EINVAL; +} + +static int ds1287_shutdown(struct clock_event_device *evt) +{ + u8 val; + + spin_lock(&rtc_lock); + + val = CMOS_READ(RTC_REG_B); + val &= ~RTC_PIE; + CMOS_WRITE(val, RTC_REG_B); + + spin_unlock(&rtc_lock); + return 0; +} + +static int ds1287_set_periodic(struct clock_event_device *evt) +{ + u8 val; + + spin_lock(&rtc_lock); + + val = CMOS_READ(RTC_REG_B); + val |= RTC_PIE; + CMOS_WRITE(val, RTC_REG_B); + + spin_unlock(&rtc_lock); + return 0; +} + +static void ds1287_event_handler(struct clock_event_device *dev) +{ +} + +static struct clock_event_device ds1287_clockevent = { + .name = "ds1287", + .features = CLOCK_EVT_FEAT_PERIODIC, + .set_next_event = ds1287_set_next_event, + .set_state_shutdown = ds1287_shutdown, + .set_state_periodic = ds1287_set_periodic, + .tick_resume = ds1287_shutdown, + .event_handler = ds1287_event_handler, +}; + +static irqreturn_t ds1287_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *cd = &ds1287_clockevent; + + /* Ack the RTC interrupt. */ + CMOS_READ(RTC_REG_C); + + cd->event_handler(cd); + + return IRQ_HANDLED; +} + +static struct irqaction ds1287_irqaction = { + .handler = ds1287_interrupt, + .flags = IRQF_PERCPU | IRQF_TIMER, + .name = "ds1287", +}; + +int __init ds1287_clockevent_init(int irq) +{ + struct clock_event_device *cd; + + cd = &ds1287_clockevent; + cd->rating = 100; + cd->irq = irq; + clockevent_set_clock(cd, 32768); + cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd); + cd->max_delta_ticks = 0x7fffffff; + cd->min_delta_ns = clockevent_delta2ns(0x300, cd); + cd->min_delta_ticks = 0x300; + cd->cpumask = cpumask_of(0); + + clockevents_register_device(&ds1287_clockevent); + + return setup_irq(irq, &ds1287_irqaction); +} |