Thomas Gleixner | 1621633 | 2019-05-19 15:51:31 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 2 | /* |
| 3 | * DS1287 clockevent driver |
| 4 | * |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 5 | * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 6 | */ |
| 7 | #include <linux/clockchips.h> |
| 8 | #include <linux/init.h> |
| 9 | #include <linux/interrupt.h> |
| 10 | #include <linux/mc146818rtc.h> |
David Howells | ca4d3e67 | 2010-10-07 14:08:54 +0100 | [diff] [blame] | 11 | #include <linux/irq.h> |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 12 | |
| 13 | #include <asm/time.h> |
| 14 | |
| 15 | int ds1287_timer_state(void) |
| 16 | { |
| 17 | return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0; |
| 18 | } |
| 19 | |
| 20 | int ds1287_set_base_clock(unsigned int hz) |
| 21 | { |
| 22 | u8 rate; |
| 23 | |
| 24 | switch (hz) { |
| 25 | case 128: |
| 26 | rate = 0x9; |
| 27 | break; |
| 28 | case 256: |
| 29 | rate = 0x8; |
| 30 | break; |
| 31 | case 1024: |
| 32 | rate = 0x6; |
| 33 | break; |
| 34 | default: |
| 35 | return -EINVAL; |
| 36 | } |
| 37 | |
| 38 | CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A); |
| 39 | |
| 40 | return 0; |
| 41 | } |
| 42 | |
| 43 | static int ds1287_set_next_event(unsigned long delta, |
| 44 | struct clock_event_device *evt) |
| 45 | { |
| 46 | return -EINVAL; |
| 47 | } |
| 48 | |
Viresh Kumar | 9f95618 | 2015-07-06 16:41:56 +0530 | [diff] [blame] | 49 | static int ds1287_shutdown(struct clock_event_device *evt) |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 50 | { |
| 51 | u8 val; |
| 52 | |
| 53 | spin_lock(&rtc_lock); |
| 54 | |
| 55 | val = CMOS_READ(RTC_REG_B); |
Viresh Kumar | 9f95618 | 2015-07-06 16:41:56 +0530 | [diff] [blame] | 56 | val &= ~RTC_PIE; |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 57 | CMOS_WRITE(val, RTC_REG_B); |
| 58 | |
| 59 | spin_unlock(&rtc_lock); |
Viresh Kumar | 9f95618 | 2015-07-06 16:41:56 +0530 | [diff] [blame] | 60 | return 0; |
| 61 | } |
| 62 | |
| 63 | static int ds1287_set_periodic(struct clock_event_device *evt) |
| 64 | { |
| 65 | u8 val; |
| 66 | |
| 67 | spin_lock(&rtc_lock); |
| 68 | |
| 69 | val = CMOS_READ(RTC_REG_B); |
| 70 | val |= RTC_PIE; |
| 71 | CMOS_WRITE(val, RTC_REG_B); |
| 72 | |
| 73 | spin_unlock(&rtc_lock); |
| 74 | return 0; |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 75 | } |
| 76 | |
| 77 | static void ds1287_event_handler(struct clock_event_device *dev) |
| 78 | { |
| 79 | } |
| 80 | |
| 81 | static struct clock_event_device ds1287_clockevent = { |
Viresh Kumar | 9f95618 | 2015-07-06 16:41:56 +0530 | [diff] [blame] | 82 | .name = "ds1287", |
| 83 | .features = CLOCK_EVT_FEAT_PERIODIC, |
| 84 | .set_next_event = ds1287_set_next_event, |
| 85 | .set_state_shutdown = ds1287_shutdown, |
| 86 | .set_state_periodic = ds1287_set_periodic, |
| 87 | .tick_resume = ds1287_shutdown, |
| 88 | .event_handler = ds1287_event_handler, |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 89 | }; |
| 90 | |
| 91 | static irqreturn_t ds1287_interrupt(int irq, void *dev_id) |
| 92 | { |
| 93 | struct clock_event_device *cd = &ds1287_clockevent; |
| 94 | |
| 95 | /* Ack the RTC interrupt. */ |
| 96 | CMOS_READ(RTC_REG_C); |
| 97 | |
| 98 | cd->event_handler(cd); |
| 99 | |
| 100 | return IRQ_HANDLED; |
| 101 | } |
| 102 | |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 103 | int __init ds1287_clockevent_init(int irq) |
| 104 | { |
afzal mohammed | ac8fd12 | 2020-03-05 17:27:53 +0530 | [diff] [blame] | 105 | unsigned long flags = IRQF_PERCPU | IRQF_TIMER; |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 106 | struct clock_event_device *cd; |
| 107 | |
| 108 | cd = &ds1287_clockevent; |
| 109 | cd->rating = 100; |
| 110 | cd->irq = irq; |
| 111 | clockevent_set_clock(cd, 32768); |
| 112 | cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd); |
Nicolai Stange | e4db9253 | 2017-03-30 21:47:32 +0200 | [diff] [blame] | 113 | cd->max_delta_ticks = 0x7fffffff; |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 114 | cd->min_delta_ns = clockevent_delta2ns(0x300, cd); |
Nicolai Stange | e4db9253 | 2017-03-30 21:47:32 +0200 | [diff] [blame] | 115 | cd->min_delta_ticks = 0x300; |
Rusty Russell | 320ab2b | 2008-12-13 21:20:26 +1030 | [diff] [blame] | 116 | cd->cpumask = cpumask_of(0); |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 117 | |
| 118 | clockevents_register_device(&ds1287_clockevent); |
| 119 | |
afzal mohammed | ac8fd12 | 2020-03-05 17:27:53 +0530 | [diff] [blame] | 120 | return request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL); |
Yoichi Yuasa | 6457d9f | 2008-04-25 12:11:44 +0900 | [diff] [blame] | 121 | } |