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 #define MLB_TIMER_ONESHOT       0
  47 #define MLB_TIMER_PERIODIC      1
  48
  49 static 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
  64 static 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
  74 static 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
  82 static 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
  87 static 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
  97 static 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
 106 static 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
 114 static 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
 125 static 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
 137 static 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
 143 static 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
 163 static u64 notrace mlb_timer_sched_read(void)
 164 {
 165         return ~readl_relaxed(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS);
 166 }
 167
 168 static 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 }
 188 TIMER_OF_DECLARE(mlb_peritimer, "socionext,milbeaut-timer",
 189                 mlb_timer_init);