linux/drivers/clocksource/timer-sprd.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2017 Spreadtrum Communications Inc.
   4 */
   5
   6#include <linux/init.h>
   7#include <linux/interrupt.h>
   8
   9#include "timer-of.h"
  10
  11#define TIMER_NAME              "sprd_timer"
  12
  13#define TIMER_LOAD_LO           0x0
  14#define TIMER_LOAD_HI           0x4
  15#define TIMER_VALUE_LO          0x8
  16#define TIMER_VALUE_HI          0xc
  17
  18#define TIMER_CTL               0x10
  19#define TIMER_CTL_PERIOD_MODE   BIT(0)
  20#define TIMER_CTL_ENABLE        BIT(1)
  21#define TIMER_CTL_64BIT_WIDTH   BIT(16)
  22
  23#define TIMER_INT               0x14
  24#define TIMER_INT_EN            BIT(0)
  25#define TIMER_INT_RAW_STS       BIT(1)
  26#define TIMER_INT_MASK_STS      BIT(2)
  27#define TIMER_INT_CLR           BIT(3)
  28
  29#define TIMER_VALUE_SHDW_LO     0x18
  30#define TIMER_VALUE_SHDW_HI     0x1c
  31
  32#define TIMER_VALUE_LO_MASK     GENMASK(31, 0)
  33
  34static void sprd_timer_enable(void __iomem *base, u32 flag)
  35{
  36        u32 val = readl_relaxed(base + TIMER_CTL);
  37
  38        val |= TIMER_CTL_ENABLE;
  39        if (flag & TIMER_CTL_64BIT_WIDTH)
  40                val |= TIMER_CTL_64BIT_WIDTH;
  41        else
  42                val &= ~TIMER_CTL_64BIT_WIDTH;
  43
  44        if (flag & TIMER_CTL_PERIOD_MODE)
  45                val |= TIMER_CTL_PERIOD_MODE;
  46        else
  47                val &= ~TIMER_CTL_PERIOD_MODE;
  48
  49        writel_relaxed(val, base + TIMER_CTL);
  50}
  51
  52static void sprd_timer_disable(void __iomem *base)
  53{
  54        u32 val = readl_relaxed(base + TIMER_CTL);
  55
  56        val &= ~TIMER_CTL_ENABLE;
  57        writel_relaxed(val, base + TIMER_CTL);
  58}
  59
  60static void sprd_timer_update_counter(void __iomem *base, unsigned long cycles)
  61{
  62        writel_relaxed(cycles & TIMER_VALUE_LO_MASK, base + TIMER_LOAD_LO);
  63        writel_relaxed(0, base + TIMER_LOAD_HI);
  64}
  65
  66static void sprd_timer_enable_interrupt(void __iomem *base)
  67{
  68        writel_relaxed(TIMER_INT_EN, base + TIMER_INT);
  69}
  70
  71static void sprd_timer_clear_interrupt(void __iomem *base)
  72{
  73        u32 val = readl_relaxed(base + TIMER_INT);
  74
  75        val |= TIMER_INT_CLR;
  76        writel_relaxed(val, base + TIMER_INT);
  77}
  78
  79static int sprd_timer_set_next_event(unsigned long cycles,
  80                                     struct clock_event_device *ce)
  81{
  82        struct timer_of *to = to_timer_of(ce);
  83
  84        sprd_timer_disable(timer_of_base(to));
  85        sprd_timer_update_counter(timer_of_base(to), cycles);
  86        sprd_timer_enable(timer_of_base(to), 0);
  87
  88        return 0;
  89}
  90
  91static int sprd_timer_set_periodic(struct clock_event_device *ce)
  92{
  93        struct timer_of *to = to_timer_of(ce);
  94
  95        sprd_timer_disable(timer_of_base(to));
  96        sprd_timer_update_counter(timer_of_base(to), timer_of_period(to));
  97        sprd_timer_enable(timer_of_base(to), TIMER_CTL_PERIOD_MODE);
  98
  99        return 0;
 100}
 101
 102static int sprd_timer_shutdown(struct clock_event_device *ce)
 103{
 104        struct timer_of *to = to_timer_of(ce);
 105
 106        sprd_timer_disable(timer_of_base(to));
 107        return 0;
 108}
 109
 110static irqreturn_t sprd_timer_interrupt(int irq, void *dev_id)
 111{
 112        struct clock_event_device *ce = (struct clock_event_device *)dev_id;
 113        struct timer_of *to = to_timer_of(ce);
 114
 115        sprd_timer_clear_interrupt(timer_of_base(to));
 116
 117        if (clockevent_state_oneshot(ce))
 118                sprd_timer_disable(timer_of_base(to));
 119
 120        ce->event_handler(ce);
 121        return IRQ_HANDLED;
 122}
 123
 124static struct timer_of to = {
 125        .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
 126
 127        .clkevt = {
 128                .name = TIMER_NAME,
 129                .rating = 300,
 130                .features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_PERIODIC |
 131                        CLOCK_EVT_FEAT_ONESHOT,
 132                .set_state_shutdown = sprd_timer_shutdown,
 133                .set_state_periodic = sprd_timer_set_periodic,
 134                .set_next_event = sprd_timer_set_next_event,
 135                .cpumask = cpu_possible_mask,
 136        },
 137
 138        .of_irq = {
 139                .handler = sprd_timer_interrupt,
 140                .flags = IRQF_TIMER | IRQF_IRQPOLL,
 141        },
 142};
 143
 144static int __init sprd_timer_init(struct device_node *np)
 145{
 146        int ret;
 147
 148        ret = timer_of_init(np, &to);
 149        if (ret)
 150                return ret;
 151
 152        sprd_timer_enable_interrupt(timer_of_base(&to));
 153        clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
 154                                        1, UINT_MAX);
 155
 156        return 0;
 157}
 158
 159static struct timer_of suspend_to = {
 160        .flags = TIMER_OF_BASE | TIMER_OF_CLOCK,
 161};
 162
 163static u64 sprd_suspend_timer_read(struct clocksource *cs)
 164{
 165        return ~(u64)readl_relaxed(timer_of_base(&suspend_to) +
 166                                   TIMER_VALUE_SHDW_LO) & cs->mask;
 167}
 168
 169static int sprd_suspend_timer_enable(struct clocksource *cs)
 170{
 171        sprd_timer_update_counter(timer_of_base(&suspend_to),
 172                                  TIMER_VALUE_LO_MASK);
 173        sprd_timer_enable(timer_of_base(&suspend_to), TIMER_CTL_PERIOD_MODE);
 174
 175        return 0;
 176}
 177
 178static void sprd_suspend_timer_disable(struct clocksource *cs)
 179{
 180        sprd_timer_disable(timer_of_base(&suspend_to));
 181}
 182
 183static struct clocksource suspend_clocksource = {
 184        .name   = "sprd_suspend_timer",
 185        .rating = 200,
 186        .read   = sprd_suspend_timer_read,
 187        .enable = sprd_suspend_timer_enable,
 188        .disable = sprd_suspend_timer_disable,
 189        .mask   = CLOCKSOURCE_MASK(32),
 190        .flags  = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
 191};
 192
 193static int __init sprd_suspend_timer_init(struct device_node *np)
 194{
 195        int ret;
 196
 197        ret = timer_of_init(np, &suspend_to);
 198        if (ret)
 199                return ret;
 200
 201        clocksource_register_hz(&suspend_clocksource,
 202                                timer_of_rate(&suspend_to));
 203
 204        return 0;
 205}
 206
 207TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init);
 208TIMER_OF_DECLARE(sc9860_persistent_timer, "sprd,sc9860-suspend-timer",
 209                 sprd_suspend_timer_init);
 210