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); 190