1 /*
2 * Rockchip timer support
3 *
4 * Copyright (C) Daniel Lezcano <daniel.lezcano@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/clk.h>
11 #include <linux/clockchips.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/sched_clock.h>
15 #include <linux/slab.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_irq.h>
19
20 #define TIMER_NAME "rk_timer"
21
22 #define TIMER_LOAD_COUNT0 0x00
23 #define TIMER_LOAD_COUNT1 0x04
24 #define TIMER_CURRENT_VALUE0 0x08
25 #define TIMER_CURRENT_VALUE1 0x0C
26 #define TIMER_CONTROL_REG3288 0x10
27 #define TIMER_CONTROL_REG3399 0x1c
28 #define TIMER_INT_STATUS 0x18
29
30 #define TIMER_DISABLE 0x0
31 #define TIMER_ENABLE 0x1
32 #define TIMER_MODE_FREE_RUNNING (0 << 1)
33 #define TIMER_MODE_USER_DEFINED_COUNT (1 << 1)
34 #define TIMER_INT_UNMASK (1 << 2)
35
36 struct rk_timer {
37 void __iomem *base;
38 void __iomem *ctrl;
39 struct clk *clk;
40 struct clk *pclk;
41 u32 freq;
42 int irq;
43 };
44
45 struct rk_clkevt {
46 struct clock_event_device ce;
47 struct rk_timer timer;
48 };
49
50 static struct rk_clkevt *rk_clkevt;
51 static struct rk_timer *rk_clksrc;
52
rk_timer(struct clock_event_device * ce)53 static inline struct rk_timer *rk_timer(struct clock_event_device *ce)
54 {
55 return &container_of(ce, struct rk_clkevt, ce)->timer;
56 }
57
rk_timer_disable(struct rk_timer * timer)58 static inline void rk_timer_disable(struct rk_timer *timer)
59 {
60 writel_relaxed(TIMER_DISABLE, timer->ctrl);
61 }
62
rk_timer_enable(struct rk_timer * timer,u32 flags)63 static inline void rk_timer_enable(struct rk_timer *timer, u32 flags)
64 {
65 writel_relaxed(TIMER_ENABLE | flags, timer->ctrl);
66 }
67
rk_timer_update_counter(unsigned long cycles,struct rk_timer * timer)68 static void rk_timer_update_counter(unsigned long cycles,
69 struct rk_timer *timer)
70 {
71 writel_relaxed(cycles, timer->base + TIMER_LOAD_COUNT0);
72 writel_relaxed(0, timer->base + TIMER_LOAD_COUNT1);
73 }
74
rk_timer_interrupt_clear(struct rk_timer * timer)75 static void rk_timer_interrupt_clear(struct rk_timer *timer)
76 {
77 writel_relaxed(1, timer->base + TIMER_INT_STATUS);
78 }
79
rk_timer_set_next_event(unsigned long cycles,struct clock_event_device * ce)80 static inline int rk_timer_set_next_event(unsigned long cycles,
81 struct clock_event_device *ce)
82 {
83 struct rk_timer *timer = rk_timer(ce);
84
85 rk_timer_disable(timer);
86 rk_timer_update_counter(cycles, timer);
87 rk_timer_enable(timer, TIMER_MODE_USER_DEFINED_COUNT |
88 TIMER_INT_UNMASK);
89 return 0;
90 }
91
rk_timer_shutdown(struct clock_event_device * ce)92 static int rk_timer_shutdown(struct clock_event_device *ce)
93 {
94 struct rk_timer *timer = rk_timer(ce);
95
96 rk_timer_disable(timer);
97 return 0;
98 }
99
rk_timer_set_periodic(struct clock_event_device * ce)100 static int rk_timer_set_periodic(struct clock_event_device *ce)
101 {
102 struct rk_timer *timer = rk_timer(ce);
103
104 rk_timer_disable(timer);
105 rk_timer_update_counter(timer->freq / HZ - 1, timer);
106 rk_timer_enable(timer, TIMER_MODE_FREE_RUNNING | TIMER_INT_UNMASK);
107 return 0;
108 }
109
rk_timer_interrupt(int irq,void * dev_id)110 static irqreturn_t rk_timer_interrupt(int irq, void *dev_id)
111 {
112 struct clock_event_device *ce = dev_id;
113 struct rk_timer *timer = rk_timer(ce);
114
115 rk_timer_interrupt_clear(timer);
116
117 if (clockevent_state_oneshot(ce))
118 rk_timer_disable(timer);
119
120 ce->event_handler(ce);
121
122 return IRQ_HANDLED;
123 }
124
rk_timer_sched_read(void)125 static u64 notrace rk_timer_sched_read(void)
126 {
127 return ~readl_relaxed(rk_clksrc->base + TIMER_CURRENT_VALUE0);
128 }
129
130 static int __init
rk_timer_probe(struct rk_timer * timer,struct device_node * np)131 rk_timer_probe(struct rk_timer *timer, struct device_node *np)
132 {
133 struct clk *timer_clk;
134 struct clk *pclk;
135 int ret = -EINVAL, irq;
136 u32 ctrl_reg = TIMER_CONTROL_REG3288;
137
138 timer->base = of_iomap(np, 0);
139 if (!timer->base) {
140 pr_err("Failed to get base address for '%s'\n", TIMER_NAME);
141 return -ENXIO;
142 }
143
144 if (of_device_is_compatible(np, "rockchip,rk3399-timer"))
145 ctrl_reg = TIMER_CONTROL_REG3399;
146
147 timer->ctrl = timer->base + ctrl_reg;
148
149 pclk = of_clk_get_by_name(np, "pclk");
150 if (IS_ERR(pclk)) {
151 ret = PTR_ERR(pclk);
152 pr_err("Failed to get pclk for '%s'\n", TIMER_NAME);
153 goto out_unmap;
154 }
155
156 ret = clk_prepare_enable(pclk);
157 if (ret) {
158 pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
159 goto out_unmap;
160 }
161 timer->pclk = pclk;
162
163 timer_clk = of_clk_get_by_name(np, "timer");
164 if (IS_ERR(timer_clk)) {
165 ret = PTR_ERR(timer_clk);
166 pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME);
167 goto out_timer_clk;
168 }
169
170 ret = clk_prepare_enable(timer_clk);
171 if (ret) {
172 pr_err("Failed to enable timer clock\n");
173 goto out_timer_clk;
174 }
175 timer->clk = timer_clk;
176
177 timer->freq = clk_get_rate(timer_clk);
178
179 irq = irq_of_parse_and_map(np, 0);
180 if (!irq) {
181 ret = -EINVAL;
182 pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
183 goto out_irq;
184 }
185 timer->irq = irq;
186
187 rk_timer_interrupt_clear(timer);
188 rk_timer_disable(timer);
189 return 0;
190
191 out_irq:
192 clk_disable_unprepare(timer_clk);
193 out_timer_clk:
194 clk_disable_unprepare(pclk);
195 out_unmap:
196 iounmap(timer->base);
197
198 return ret;
199 }
200
rk_timer_cleanup(struct rk_timer * timer)201 static void __init rk_timer_cleanup(struct rk_timer *timer)
202 {
203 clk_disable_unprepare(timer->clk);
204 clk_disable_unprepare(timer->pclk);
205 iounmap(timer->base);
206 }
207
rk_clkevt_init(struct device_node * np)208 static int __init rk_clkevt_init(struct device_node *np)
209 {
210 struct clock_event_device *ce;
211 int ret = -EINVAL;
212
213 rk_clkevt = kzalloc(sizeof(struct rk_clkevt), GFP_KERNEL);
214 if (!rk_clkevt) {
215 ret = -ENOMEM;
216 goto out;
217 }
218
219 ret = rk_timer_probe(&rk_clkevt->timer, np);
220 if (ret)
221 goto out_probe;
222
223 ce = &rk_clkevt->ce;
224 ce->name = TIMER_NAME;
225 ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
226 CLOCK_EVT_FEAT_DYNIRQ;
227 ce->set_next_event = rk_timer_set_next_event;
228 ce->set_state_shutdown = rk_timer_shutdown;
229 ce->set_state_periodic = rk_timer_set_periodic;
230 ce->irq = rk_clkevt->timer.irq;
231 ce->cpumask = cpu_possible_mask;
232 ce->rating = 250;
233
234 ret = request_irq(rk_clkevt->timer.irq, rk_timer_interrupt, IRQF_TIMER,
235 TIMER_NAME, ce);
236 if (ret) {
237 pr_err("Failed to initialize '%s': %d\n",
238 TIMER_NAME, ret);
239 goto out_irq;
240 }
241
242 clockevents_config_and_register(&rk_clkevt->ce,
243 rk_clkevt->timer.freq, 1, UINT_MAX);
244 return 0;
245
246 out_irq:
247 rk_timer_cleanup(&rk_clkevt->timer);
248 out_probe:
249 kfree(rk_clkevt);
250 out:
251 /* Leave rk_clkevt not NULL to prevent future init */
252 rk_clkevt = ERR_PTR(ret);
253 return ret;
254 }
255
rk_clksrc_init(struct device_node * np)256 static int __init rk_clksrc_init(struct device_node *np)
257 {
258 int ret = -EINVAL;
259
260 rk_clksrc = kzalloc(sizeof(struct rk_timer), GFP_KERNEL);
261 if (!rk_clksrc) {
262 ret = -ENOMEM;
263 goto out;
264 }
265
266 ret = rk_timer_probe(rk_clksrc, np);
267 if (ret)
268 goto out_probe;
269
270 rk_timer_update_counter(UINT_MAX, rk_clksrc);
271 rk_timer_enable(rk_clksrc, 0);
272
273 ret = clocksource_mmio_init(rk_clksrc->base + TIMER_CURRENT_VALUE0,
274 TIMER_NAME, rk_clksrc->freq, 250, 32,
275 clocksource_mmio_readl_down);
276 if (ret) {
277 pr_err("Failed to register clocksource\n");
278 goto out_clocksource;
279 }
280
281 sched_clock_register(rk_timer_sched_read, 32, rk_clksrc->freq);
282 return 0;
283
284 out_clocksource:
285 rk_timer_cleanup(rk_clksrc);
286 out_probe:
287 kfree(rk_clksrc);
288 out:
289 /* Leave rk_clksrc not NULL to prevent future init */
290 rk_clksrc = ERR_PTR(ret);
291 return ret;
292 }
293
rk_timer_init(struct device_node * np)294 static int __init rk_timer_init(struct device_node *np)
295 {
296 if (!rk_clkevt)
297 return rk_clkevt_init(np);
298
299 if (!rk_clksrc)
300 return rk_clksrc_init(np);
301
302 pr_err("Too many timer definitions for '%s'\n", TIMER_NAME);
303 return -EINVAL;
304 }
305
306 TIMER_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer", rk_timer_init);
307 TIMER_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer", rk_timer_init);
308
