1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * linux/drivers/clocksource/timer-sp.c
4 *
5 * Copyright (C) 1999 - 2003 ARM Limited
6 * Copyright (C) 2000 Deep Blue Solutions Ltd
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/clk.h>
12 #include <linux/clocksource.h>
13 #include <linux/clockchips.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/io.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/of_clk.h>
21 #include <linux/of_irq.h>
22 #include <linux/sched_clock.h>
23
24 #include "timer-sp.h"
25
26 /* Hisilicon 64-bit timer(a variant of ARM SP804) */
27 #define HISI_TIMER_1_BASE 0x00
28 #define HISI_TIMER_2_BASE 0x40
29 #define HISI_TIMER_LOAD 0x00
30 #define HISI_TIMER_LOAD_H 0x04
31 #define HISI_TIMER_VALUE 0x08
32 #define HISI_TIMER_VALUE_H 0x0c
33 #define HISI_TIMER_CTRL 0x10
34 #define HISI_TIMER_INTCLR 0x14
35 #define HISI_TIMER_RIS 0x18
36 #define HISI_TIMER_MIS 0x1c
37 #define HISI_TIMER_BGLOAD 0x20
38 #define HISI_TIMER_BGLOAD_H 0x24
39
40 static struct sp804_timer arm_sp804_timer __initdata = {
41 .load = TIMER_LOAD,
42 .value = TIMER_VALUE,
43 .ctrl = TIMER_CTRL,
44 .intclr = TIMER_INTCLR,
45 .timer_base = {TIMER_1_BASE, TIMER_2_BASE},
46 .width = 32,
47 };
48
49 static struct sp804_timer hisi_sp804_timer __initdata = {
50 .load = HISI_TIMER_LOAD,
51 .load_h = HISI_TIMER_LOAD_H,
52 .value = HISI_TIMER_VALUE,
53 .value_h = HISI_TIMER_VALUE_H,
54 .ctrl = HISI_TIMER_CTRL,
55 .intclr = HISI_TIMER_INTCLR,
56 .timer_base = {HISI_TIMER_1_BASE, HISI_TIMER_2_BASE},
57 .width = 64,
58 };
59
60 static struct sp804_clkevt sp804_clkevt[NR_TIMERS];
61
sp804_get_clock_rate(struct clk * clk,const char * name)62 static long __init sp804_get_clock_rate(struct clk *clk, const char *name)
63 {
64 int err;
65
66 if (!clk)
67 clk = clk_get_sys("sp804", name);
68 if (IS_ERR(clk)) {
69 pr_err("%s clock not found: %ld\n", name, PTR_ERR(clk));
70 return PTR_ERR(clk);
71 }
72
73 err = clk_prepare_enable(clk);
74 if (err) {
75 pr_err("clock failed to enable: %d\n", err);
76 clk_put(clk);
77 return err;
78 }
79
80 return clk_get_rate(clk);
81 }
82
sp804_clkevt_get(void __iomem * base)83 static struct sp804_clkevt * __init sp804_clkevt_get(void __iomem *base)
84 {
85 int i;
86
87 for (i = 0; i < NR_TIMERS; i++) {
88 if (sp804_clkevt[i].base == base)
89 return &sp804_clkevt[i];
90 }
91
92 /* It's impossible to reach here */
93 WARN_ON(1);
94
95 return NULL;
96 }
97
98 static struct sp804_clkevt *sched_clkevt;
99
sp804_read(void)100 static u64 notrace sp804_read(void)
101 {
102 return ~readl_relaxed(sched_clkevt->value);
103 }
104
sp804_clocksource_and_sched_clock_init(void __iomem * base,const char * name,struct clk * clk,int use_sched_clock)105 static int __init sp804_clocksource_and_sched_clock_init(void __iomem *base,
106 const char *name,
107 struct clk *clk,
108 int use_sched_clock)
109 {
110 long rate;
111 struct sp804_clkevt *clkevt;
112
113 rate = sp804_get_clock_rate(clk, name);
114 if (rate < 0)
115 return -EINVAL;
116
117 clkevt = sp804_clkevt_get(base);
118
119 writel(0, clkevt->ctrl);
120 writel(0xffffffff, clkevt->load);
121 writel(0xffffffff, clkevt->value);
122 if (clkevt->width == 64) {
123 writel(0xffffffff, clkevt->load_h);
124 writel(0xffffffff, clkevt->value_h);
125 }
126 writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
127 clkevt->ctrl);
128
129 clocksource_mmio_init(clkevt->value, name,
130 rate, 200, 32, clocksource_mmio_readl_down);
131
132 if (use_sched_clock) {
133 sched_clkevt = clkevt;
134 sched_clock_register(sp804_read, 32, rate);
135 }
136
137 return 0;
138 }
139
140
141 static struct sp804_clkevt *common_clkevt;
142
143 /*
144 * IRQ handler for the timer
145 */
sp804_timer_interrupt(int irq,void * dev_id)146 static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
147 {
148 struct clock_event_device *evt = dev_id;
149
150 /* clear the interrupt */
151 writel(1, common_clkevt->intclr);
152
153 evt->event_handler(evt);
154
155 return IRQ_HANDLED;
156 }
157
evt_timer_shutdown(struct clock_event_device * evt)158 static inline void evt_timer_shutdown(struct clock_event_device *evt)
159 {
160 writel(0, common_clkevt->ctrl);
161 }
162
sp804_shutdown(struct clock_event_device * evt)163 static int sp804_shutdown(struct clock_event_device *evt)
164 {
165 evt_timer_shutdown(evt);
166 return 0;
167 }
168
sp804_set_periodic(struct clock_event_device * evt)169 static int sp804_set_periodic(struct clock_event_device *evt)
170 {
171 unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
172 TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
173
174 evt_timer_shutdown(evt);
175 writel(common_clkevt->reload, common_clkevt->load);
176 writel(ctrl, common_clkevt->ctrl);
177 return 0;
178 }
179
sp804_set_next_event(unsigned long next,struct clock_event_device * evt)180 static int sp804_set_next_event(unsigned long next,
181 struct clock_event_device *evt)
182 {
183 unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
184 TIMER_CTRL_ONESHOT | TIMER_CTRL_ENABLE;
185
186 writel(next, common_clkevt->load);
187 writel(ctrl, common_clkevt->ctrl);
188
189 return 0;
190 }
191
192 static struct clock_event_device sp804_clockevent = {
193 .features = CLOCK_EVT_FEAT_PERIODIC |
194 CLOCK_EVT_FEAT_ONESHOT |
195 CLOCK_EVT_FEAT_DYNIRQ,
196 .set_state_shutdown = sp804_shutdown,
197 .set_state_periodic = sp804_set_periodic,
198 .set_state_oneshot = sp804_shutdown,
199 .tick_resume = sp804_shutdown,
200 .set_next_event = sp804_set_next_event,
201 .rating = 300,
202 };
203
sp804_clockevents_init(void __iomem * base,unsigned int irq,struct clk * clk,const char * name)204 static int __init sp804_clockevents_init(void __iomem *base, unsigned int irq,
205 struct clk *clk, const char *name)
206 {
207 struct clock_event_device *evt = &sp804_clockevent;
208 long rate;
209
210 rate = sp804_get_clock_rate(clk, name);
211 if (rate < 0)
212 return -EINVAL;
213
214 common_clkevt = sp804_clkevt_get(base);
215 common_clkevt->reload = DIV_ROUND_CLOSEST(rate, HZ);
216 evt->name = name;
217 evt->irq = irq;
218 evt->cpumask = cpu_possible_mask;
219
220 writel(0, common_clkevt->ctrl);
221
222 if (request_irq(irq, sp804_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
223 "timer", &sp804_clockevent))
224 pr_err("request_irq() failed\n");
225 clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
226
227 return 0;
228 }
229
sp804_clkevt_init(struct sp804_timer * timer,void __iomem * base)230 static void __init sp804_clkevt_init(struct sp804_timer *timer, void __iomem *base)
231 {
232 int i;
233
234 for (i = 0; i < NR_TIMERS; i++) {
235 void __iomem *timer_base;
236 struct sp804_clkevt *clkevt;
237
238 timer_base = base + timer->timer_base[i];
239 clkevt = &sp804_clkevt[i];
240 clkevt->base = timer_base;
241 clkevt->load = timer_base + timer->load;
242 clkevt->load_h = timer_base + timer->load_h;
243 clkevt->value = timer_base + timer->value;
244 clkevt->value_h = timer_base + timer->value_h;
245 clkevt->ctrl = timer_base + timer->ctrl;
246 clkevt->intclr = timer_base + timer->intclr;
247 clkevt->width = timer->width;
248 }
249 }
250
sp804_of_init(struct device_node * np,struct sp804_timer * timer)251 static int __init sp804_of_init(struct device_node *np, struct sp804_timer *timer)
252 {
253 static bool initialized = false;
254 void __iomem *base;
255 void __iomem *timer1_base;
256 void __iomem *timer2_base;
257 int irq, ret = -EINVAL;
258 u32 irq_num = 0;
259 struct clk *clk1, *clk2;
260 const char *name = of_get_property(np, "compatible", NULL);
261
262 if (initialized) {
263 pr_debug("%pOF: skipping further SP804 timer device\n", np);
264 return 0;
265 }
266
267 base = of_iomap(np, 0);
268 if (!base)
269 return -ENXIO;
270
271 timer1_base = base + timer->timer_base[0];
272 timer2_base = base + timer->timer_base[1];
273
274 /* Ensure timers are disabled */
275 writel(0, timer1_base + timer->ctrl);
276 writel(0, timer2_base + timer->ctrl);
277
278 clk1 = of_clk_get(np, 0);
279 if (IS_ERR(clk1))
280 clk1 = NULL;
281
282 /* Get the 2nd clock if the timer has 3 timer clocks */
283 if (of_clk_get_parent_count(np) == 3) {
284 clk2 = of_clk_get(np, 1);
285 if (IS_ERR(clk2)) {
286 pr_err("%pOFn clock not found: %d\n", np,
287 (int)PTR_ERR(clk2));
288 clk2 = NULL;
289 }
290 } else
291 clk2 = clk1;
292
293 irq = irq_of_parse_and_map(np, 0);
294 if (irq <= 0)
295 goto err;
296
297 sp804_clkevt_init(timer, base);
298
299 of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
300 if (irq_num == 2) {
301
302 ret = sp804_clockevents_init(timer2_base, irq, clk2, name);
303 if (ret)
304 goto err;
305
306 ret = sp804_clocksource_and_sched_clock_init(timer1_base,
307 name, clk1, 1);
308 if (ret)
309 goto err;
310 } else {
311
312 ret = sp804_clockevents_init(timer1_base, irq, clk1, name);
313 if (ret)
314 goto err;
315
316 ret = sp804_clocksource_and_sched_clock_init(timer2_base,
317 name, clk2, 1);
318 if (ret)
319 goto err;
320 }
321 initialized = true;
322
323 return 0;
324 err:
325 iounmap(base);
326 return ret;
327 }
328
arm_sp804_of_init(struct device_node * np)329 static int __init arm_sp804_of_init(struct device_node *np)
330 {
331 return sp804_of_init(np, &arm_sp804_timer);
332 }
333 TIMER_OF_DECLARE(sp804, "arm,sp804", arm_sp804_of_init);
334
hisi_sp804_of_init(struct device_node * np)335 static int __init hisi_sp804_of_init(struct device_node *np)
336 {
337 return sp804_of_init(np, &hisi_sp804_timer);
338 }
339 TIMER_OF_DECLARE(hisi_sp804, "hisilicon,sp804", hisi_sp804_of_init);
340
integrator_cp_of_init(struct device_node * np)341 static int __init integrator_cp_of_init(struct device_node *np)
342 {
343 static int init_count = 0;
344 void __iomem *base;
345 int irq, ret = -EINVAL;
346 const char *name = of_get_property(np, "compatible", NULL);
347 struct clk *clk;
348
349 base = of_iomap(np, 0);
350 if (!base) {
351 pr_err("Failed to iomap\n");
352 return -ENXIO;
353 }
354
355 clk = of_clk_get(np, 0);
356 if (IS_ERR(clk)) {
357 pr_err("Failed to get clock\n");
358 return PTR_ERR(clk);
359 }
360
361 /* Ensure timer is disabled */
362 writel(0, base + arm_sp804_timer.ctrl);
363
364 if (init_count == 2 || !of_device_is_available(np))
365 goto err;
366
367 sp804_clkevt_init(&arm_sp804_timer, base);
368
369 if (!init_count) {
370 ret = sp804_clocksource_and_sched_clock_init(base,
371 name, clk, 0);
372 if (ret)
373 goto err;
374 } else {
375 irq = irq_of_parse_and_map(np, 0);
376 if (irq <= 0)
377 goto err;
378
379 ret = sp804_clockevents_init(base, irq, clk, name);
380 if (ret)
381 goto err;
382 }
383
384 init_count++;
385 return 0;
386 err:
387 iounmap(base);
388 return ret;
389 }
390 TIMER_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);
391