projects/linux·blob v6.6 · refs

195 lines · 4.6 KiB

1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * RDA8810PL SoC timer driver
4 *
5 * Copyright RDA Microelectronics Company Limited
6 * Copyright (c) 2017 Andreas Färber
7 * Copyright (c) 2018 Manivannan Sadhasivam
8 *
9 * RDA8810PL has two independent timers: OSTIMER (56 bit) and HWTIMER (64 bit).
10 * Each timer provides optional interrupt support. In this driver, OSTIMER is
11 * used for clockevents and HWTIMER is used for clocksource.
12 */
13
14#include <linux/init.h>
15#include <linux/interrupt.h>
16
17#include "timer-of.h"
18
19#define RDA_OSTIMER_LOADVAL_L 0x000
20#define RDA_OSTIMER_CTRL 0x004
21#define RDA_HWTIMER_LOCKVAL_L 0x024
22#define RDA_HWTIMER_LOCKVAL_H 0x028
23#define RDA_TIMER_IRQ_MASK_SET 0x02c
24#define RDA_TIMER_IRQ_MASK_CLR 0x030
25#define RDA_TIMER_IRQ_CLR 0x034
26
27#define RDA_OSTIMER_CTRL_ENABLE BIT(24)
28#define RDA_OSTIMER_CTRL_REPEAT BIT(28)
29#define RDA_OSTIMER_CTRL_LOAD BIT(30)
30
31#define RDA_TIMER_IRQ_MASK_OSTIMER BIT(0)
32
33#define RDA_TIMER_IRQ_CLR_OSTIMER BIT(0)
34
35static int rda_ostimer_start(void __iomem *base, bool periodic, u64 cycles)
36{
37 u32 ctrl, load_l;
38
39 load_l = (u32)cycles;
40 ctrl = ((cycles >> 32) & 0xffffff);
41 ctrl |= RDA_OSTIMER_CTRL_LOAD | RDA_OSTIMER_CTRL_ENABLE;
42 if (periodic)
43 ctrl |= RDA_OSTIMER_CTRL_REPEAT;
44
45 /* Enable ostimer interrupt first */
46 writel_relaxed(RDA_TIMER_IRQ_MASK_OSTIMER,
47 base + RDA_TIMER_IRQ_MASK_SET);
48
49 /* Write low 32 bits first, high 24 bits are with ctrl */
50 writel_relaxed(load_l, base + RDA_OSTIMER_LOADVAL_L);
51 writel_relaxed(ctrl, base + RDA_OSTIMER_CTRL);
52
53 return 0;
54}
55
56static int rda_ostimer_stop(void __iomem *base)
57{
58 /* Disable ostimer interrupt first */
59 writel_relaxed(RDA_TIMER_IRQ_MASK_OSTIMER,
60 base + RDA_TIMER_IRQ_MASK_CLR);
61
62 writel_relaxed(0, base + RDA_OSTIMER_CTRL);
63
64 return 0;
65}
66
67static int rda_ostimer_set_state_shutdown(struct clock_event_device *evt)
68{
69 struct timer_of *to = to_timer_of(evt);
70
71 rda_ostimer_stop(timer_of_base(to));
72
73 return 0;
74}
75
76static int rda_ostimer_set_state_oneshot(struct clock_event_device *evt)
77{
78 struct timer_of *to = to_timer_of(evt);
79
80 rda_ostimer_stop(timer_of_base(to));
81
82 return 0;
83}
84
85static int rda_ostimer_set_state_periodic(struct clock_event_device *evt)
86{
87 struct timer_of *to = to_timer_of(evt);
88 unsigned long cycles_per_jiffy;
89
90 rda_ostimer_stop(timer_of_base(to));
91
92 cycles_per_jiffy = ((unsigned long long)NSEC_PER_SEC / HZ *
93 evt->mult) >> evt->shift;
94 rda_ostimer_start(timer_of_base(to), true, cycles_per_jiffy);
95
96 return 0;
97}
98
99static int rda_ostimer_tick_resume(struct clock_event_device *evt)
100{
101 return 0;
102}
103
104static int rda_ostimer_set_next_event(unsigned long evt,
105 struct clock_event_device *ev)
106{
107 struct timer_of *to = to_timer_of(ev);
108
109 rda_ostimer_start(timer_of_base(to), false, evt);
110
111 return 0;
112}
113
114static irqreturn_t rda_ostimer_interrupt(int irq, void *dev_id)
115{
116 struct clock_event_device *evt = dev_id;
117 struct timer_of *to = to_timer_of(evt);
118
119 /* clear timer int */
120 writel_relaxed(RDA_TIMER_IRQ_CLR_OSTIMER,
121 timer_of_base(to) + RDA_TIMER_IRQ_CLR);
122
123 if (evt->event_handler)
124 evt->event_handler(evt);
125
126 return IRQ_HANDLED;
127}
128
129static struct timer_of rda_ostimer_of = {
130 .flags = TIMER_OF_IRQ | TIMER_OF_BASE,
131
132 .clkevt = {
133 .name = "rda-ostimer",
134 .rating = 250,
135 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
136 CLOCK_EVT_FEAT_DYNIRQ,
137 .set_state_shutdown = rda_ostimer_set_state_shutdown,
138 .set_state_oneshot = rda_ostimer_set_state_oneshot,
139 .set_state_periodic = rda_ostimer_set_state_periodic,
140 .tick_resume = rda_ostimer_tick_resume,
141 .set_next_event = rda_ostimer_set_next_event,
142 },
143
144 .of_base = {
145 .name = "rda-timer",
146 .index = 0,
147 },
148
149 .of_irq = {
150 .name = "ostimer",
151 .handler = rda_ostimer_interrupt,
152 .flags = IRQF_TIMER,
153 },
154};
155
156static u64 rda_hwtimer_read(struct clocksource *cs)
157{
158 void __iomem *base = timer_of_base(&rda_ostimer_of);
159 u32 lo, hi;
160
161 /* Always read low 32 bits first */
162 do {
163 lo = readl_relaxed(base + RDA_HWTIMER_LOCKVAL_L);
164 hi = readl_relaxed(base + RDA_HWTIMER_LOCKVAL_H);
165 } while (hi != readl_relaxed(base + RDA_HWTIMER_LOCKVAL_H));
166
167 return ((u64)hi << 32) | lo;
168}
169
170static struct clocksource rda_hwtimer_clocksource = {
171 .name = "rda-timer",
172 .rating = 400,
173 .read = rda_hwtimer_read,
174 .mask = CLOCKSOURCE_MASK(64),
175 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
176};
177
178static int __init rda_timer_init(struct device_node *np)
179{
180 unsigned long rate = 2000000;
181 int ret;
182
183 ret = timer_of_init(np, &rda_ostimer_of);
184 if (ret)
185 return ret;
186
187 clocksource_register_hz(&rda_hwtimer_clocksource, rate);
188
189 clockevents_config_and_register(&rda_ostimer_of.clkevt, rate,
190 0x2, UINT_MAX);
191
192 return 0;
193}
194
195TIMER_OF_DECLARE(rda8810pl, "rda,8810pl-timer", rda_timer_init);