drivers/clocksource/timer-milbeaut.c

   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
  47 static irqreturn_t mlb_timer_interrupt(int irq, void *dev_id)
  48 {
  49         struct clock_event_device *clk = dev_id;
  50         struct timer_of *to = to_timer_of(clk);
  51         u32 val;
  52
  53         val = readl_relaxed(timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  54         val &= ~MLB_TMR_TMCSR_UF;
  55         writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  56
  57         clk->event_handler(clk);
  58
  59         return IRQ_HANDLED;
  60 }
  61
  62 static int mlb_set_state_periodic(struct clock_event_device *clk)
  63 {
  64         struct timer_of *to = to_timer_of(clk);
  65         u32 val = MLB_TMR_TMCSR_CSL_DIV2;
  66
  67         writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  68
  69         writel_relaxed(to->of_clk.period, timer_of_base(to) +
  70                                 MLB_TMR_EVT_TMRLR1_OFS);
  71         val |= MLB_TMR_TMCSR_RELD | MLB_TMR_TMCSR_CNTE |
  72                 MLB_TMR_TMCSR_TRG | MLB_TMR_TMCSR_INTE;
  73         writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  74         return 0;
  75 }
  76
  77 static int mlb_set_state_oneshot(struct clock_event_device *clk)
  78 {
  79         struct timer_of *to = to_timer_of(clk);
  80         u32 val = MLB_TMR_TMCSR_CSL_DIV2;
  81
  82         writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
  83         return 0;
  84 }
  85
  86 static int mlb_clkevt_next_event(unsigned long event,
  87                                    struct clock_event_device *clk)
  88 {
  89         struct timer_of *to = to_timer_of(clk);
  90
  91         writel_relaxed(event, timer_of_base(to) + MLB_TMR_EVT_TMRLR1_OFS);
  92         writel_relaxed(MLB_TMR_TMCSR_CSL_DIV2 |
  93                         MLB_TMR_TMCSR_CNTE | MLB_TMR_TMCSR_INTE |
  94                         MLB_TMR_TMCSR_TRG, timer_of_base(to) +
  95                         MLB_TMR_EVT_TMCSR_OFS);
  96         return 0;
  97 }
  98
  99 static int mlb_config_clock_source(struct timer_of *to)
 100 {
 101         writel_relaxed(0, timer_of_base(to) + MLB_TMR_SRC_TMCSR_OFS);
 102         writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMR_OFS);
 103         writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMRLR1_OFS);
 104         writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMRLR2_OFS);
 105         writel_relaxed(BIT(4) | BIT(1) | BIT(0), timer_of_base(to) +
 106                 MLB_TMR_SRC_TMCSR_OFS);
 107         return 0;
 108 }
 109
 110 static int mlb_config_clock_event(struct timer_of *to)
 111 {
 112         writel_relaxed(0, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 113         return 0;
 114 }
 115
 116 static struct timer_of to = {
 117         .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
 118
 119         .clkevt = {
 120                 .name = "mlb-clkevt",
 121                 .rating = MLB_TIMER_RATING,
 122                 .cpumask = cpu_possible_mask,
 123                 .features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_ONESHOT,
 124                 .set_state_oneshot = mlb_set_state_oneshot,
 125                 .set_state_periodic = mlb_set_state_periodic,
 126                 .set_next_event = mlb_clkevt_next_event,
 127         },
 128
 129         .of_irq = {
 130                 .flags = IRQF_TIMER | IRQF_IRQPOLL,
 131                 .handler = mlb_timer_interrupt,
 132         },
 133 };
 134
 135 static u64 notrace mlb_timer_sched_read(void)
 136 {
 137         return ~readl_relaxed(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS);
 138 }
 139
 140 static int __init mlb_timer_init(struct device_node *node)
 141 {
 142         int ret;
 143         unsigned long rate;
 144
 145         ret = timer_of_init(node, &to);
 146         if (ret)
 147                 return ret;
 148
 149         rate = timer_of_rate(&to) / MLB_TMR_DIV_CNT;
 150         mlb_config_clock_source(&to);
 151         clocksource_mmio_init(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS,
 152                 node->name, rate, MLB_TIMER_RATING, 32,
 153                 clocksource_mmio_readl_down);
 154         sched_clock_register(mlb_timer_sched_read, 32, rate);
 155         mlb_config_clock_event(&to);
 156         clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), 15,
 157                 0xffffffff);
 158         return 0;
 159 }
 160 TIMER_OF_DECLARE(mlb_peritimer, "socionext,milbeaut-timer",
 161                 mlb_timer_init);