linux/drivers/clocksource/timer-milbeaut.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2018 Socionext Inc.
   4 */
   5
   6#include <linux/clk.h>
   7#include <linux/interrupt.h>
   8#include <linux/irq.h>
   9#include <linux/irqreturn.h>
  10#include <linux/sched_clock.h>
  11#include "timer-of.h"
  12
  13#define MLB_TMR_TMCSR_OFS       0x0
  14#define MLB_TMR_TMR_OFS         0x4
  15#define MLB_TMR_TMRLR1_OFS      0x8
  16#define MLB_TMR_TMRLR2_OFS      0xc
  17#define MLB_TMR_REGSZPCH        0x10
  18
  19#define MLB_TMR_TMCSR_OUTL      BIT(5)
  20#define MLB_TMR_TMCSR_RELD      BIT(4)
  21#define MLB_TMR_TMCSR_INTE      BIT(3)
  22#define MLB_TMR_TMCSR_UF        BIT(2)
  23#define MLB_TMR_TMCSR_CNTE      BIT(1)
  24#define MLB_TMR_TMCSR_TRG       BIT(0)
  25
  26#define MLB_TMR_TMCSR_CSL_DIV2  0
  27#define MLB_TMR_DIV_CNT         2
  28
  29#define MLB_TMR_SRC_CH          1
  30#define MLB_TMR_EVT_CH          0
  31
  32#define MLB_TMR_SRC_CH_OFS      (MLB_TMR_REGSZPCH * MLB_TMR_SRC_CH)
  33#define MLB_TMR_EVT_CH_OFS      (MLB_TMR_REGSZPCH * MLB_TMR_EVT_CH)
  34
  35#define MLB_TMR_SRC_TMCSR_OFS   (MLB_TMR_SRC_CH_OFS + MLB_TMR_TMCSR_OFS)
  36#define MLB_TMR_SRC_TMR_OFS     (MLB_TMR_SRC_CH_OFS + MLB_TMR_TMR_OFS)
  37#define MLB_TMR_SRC_TMRLR1_OFS  (MLB_TMR_SRC_CH_OFS + MLB_TMR_TMRLR1_OFS)
  38#define MLB_TMR_SRC_TMRLR2_OFS  (MLB_TMR_SRC_CH_OFS + MLB_TMR_TMRLR2_OFS)
  39
  40#define MLB_TMR_EVT_TMCSR_OFS   (MLB_TMR_EVT_CH_OFS + MLB_TMR_TMCSR_OFS)
  41#define MLB_TMR_EVT_TMR_OFS     (MLB_TMR_EVT_CH_OFS + MLB_TMR_TMR_OFS)
  42#define MLB_TMR_EVT_TMRLR1_OFS  (MLB_TMR_EVT_CH_OFS + MLB_TMR_TMRLR1_OFS)
  43#define MLB_TMR_EVT_TMRLR2_OFS  (MLB_TMR_EVT_CH_OFS + MLB_TMR_TMRLR2_OFS)
  44
  45#define MLB_TIMER_RATING        500
  46#define MLB_TIMER_ONESHOT       0
  47#define MLB_TIMER_PERIODIC      1
  48
  49static irqreturn_t mlb_timer_interrupt(int irq, void *dev_id)
  50{
  51        struct clock_event_device *clk = dev_id;
  52        struct timer_of *to = to_timer_of(clk);
  53        u32 val;
  54
  55        val = readl_relaxed(timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  56        val &= ~MLB_TMR_TMCSR_UF;
  57        writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  58
  59        clk->event_handler(clk);
  60
  61        return IRQ_HANDLED;
  62}
  63
  64static void mlb_evt_timer_start(struct timer_of *to, bool periodic)
  65{
  66        u32 val = MLB_TMR_TMCSR_CSL_DIV2;
  67
  68        val |= MLB_TMR_TMCSR_CNTE | MLB_TMR_TMCSR_TRG | MLB_TMR_TMCSR_INTE;
  69        if (periodic)
  70                val |= MLB_TMR_TMCSR_RELD;
  71        writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  72}
  73
  74static void mlb_evt_timer_stop(struct timer_of *to)
  75{
  76        u32 val = readl_relaxed(timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  77
  78        val &= ~MLB_TMR_TMCSR_CNTE;
  79        writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  80}
  81
  82static void mlb_evt_timer_register_count(struct timer_of *to, unsigned long cnt)
  83{
  84        writel_relaxed(cnt, timer_of_base(to) + MLB_TMR_EVT_TMRLR1_OFS);
  85}
  86
  87static int mlb_set_state_periodic(struct clock_event_device *clk)
  88{
  89        struct timer_of *to = to_timer_of(clk);
  90
  91        mlb_evt_timer_stop(to);
  92        mlb_evt_timer_register_count(to, to->of_clk.period);
  93        mlb_evt_timer_start(to, MLB_TIMER_PERIODIC);
  94        return 0;
  95}
  96
  97static int mlb_set_state_oneshot(struct clock_event_device *clk)
  98{
  99        struct timer_of *to = to_timer_of(clk);
 100
 101        mlb_evt_timer_stop(to);
 102        mlb_evt_timer_start(to, MLB_TIMER_ONESHOT);
 103        return 0;
 104}
 105
 106static int mlb_set_state_shutdown(struct clock_event_device *clk)
 107{
 108        struct timer_of *to = to_timer_of(clk);
 109
 110        mlb_evt_timer_stop(to);
 111        return 0;
 112}
 113
 114static int mlb_clkevt_next_event(unsigned long event,
 115                                   struct clock_event_device *clk)
 116{
 117        struct timer_of *to = to_timer_of(clk);
 118
 119        mlb_evt_timer_stop(to);
 120        mlb_evt_timer_register_count(to, event);
 121        mlb_evt_timer_start(to, MLB_TIMER_ONESHOT);
 122        return 0;
 123}
 124
 125static int mlb_config_clock_source(struct timer_of *to)
 126{
 127        u32 val = MLB_TMR_TMCSR_CSL_DIV2;
 128
 129        writel_relaxed(val, timer_of_base(to) + MLB_TMR_SRC_TMCSR_OFS);
 130        writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMRLR1_OFS);
 131        writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMRLR2_OFS);
 132        val |= MLB_TMR_TMCSR_RELD | MLB_TMR_TMCSR_CNTE | MLB_TMR_TMCSR_TRG;
 133        writel_relaxed(val, timer_of_base(to) + MLB_TMR_SRC_TMCSR_OFS);
 134        return 0;
 135}
 136
 137static int mlb_config_clock_event(struct timer_of *to)
 138{
 139        writel_relaxed(0, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 140        return 0;
 141}
 142
 143static struct timer_of to = {
 144        .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
 145
 146        .clkevt = {
 147                .name = "mlb-clkevt",
 148                .rating = MLB_TIMER_RATING,
 149                .cpumask = cpu_possible_mask,
 150                .features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_ONESHOT,
 151                .set_state_oneshot = mlb_set_state_oneshot,
 152                .set_state_periodic = mlb_set_state_periodic,
 153                .set_state_shutdown = mlb_set_state_shutdown,
 154                .set_next_event = mlb_clkevt_next_event,
 155        },
 156
 157        .of_irq = {
 158                .flags = IRQF_TIMER | IRQF_IRQPOLL,
 159                .handler = mlb_timer_interrupt,
 160        },
 161};
 162
 163static u64 notrace mlb_timer_sched_read(void)
 164{
 165        return ~readl_relaxed(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS);
 166}
 167
 168static int __init mlb_timer_init(struct device_node *node)
 169{
 170        int ret;
 171        unsigned long rate;
 172
 173        ret = timer_of_init(node, &to);
 174        if (ret)
 175                return ret;
 176
 177        rate = timer_of_rate(&to) / MLB_TMR_DIV_CNT;
 178        mlb_config_clock_source(&to);
 179        clocksource_mmio_init(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS,
 180                node->name, rate, MLB_TIMER_RATING, 32,
 181                clocksource_mmio_readl_down);
 182        sched_clock_register(mlb_timer_sched_read, 32, rate);
 183        mlb_config_clock_event(&to);
 184        clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), 15,
 185                0xffffffff);
 186        return 0;
 187}
 188TIMER_OF_DECLARE(mlb_peritimer, "socionext,milbeaut-timer",
 189                mlb_timer_init);
 190