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189 lines · 5.1 KiB

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);