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 
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 
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 
100 static u64 notrace sp804_read(void)
101 {
102 	return ~readl_relaxed(sched_clkevt->value);
103 }
104 
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  */
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 
158 static inline void timer_shutdown(struct clock_event_device *evt)
159 {
160 	writel(0, common_clkevt->ctrl);
161 }
162 
163 static int sp804_shutdown(struct clock_event_device *evt)
164 {
165 	timer_shutdown(evt);
166 	return 0;
167 }
168 
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 	timer_shutdown(evt);
175 	writel(common_clkevt->reload, common_clkevt->load);
176 	writel(ctrl, common_clkevt->ctrl);
177 	return 0;
178 }
179 
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 
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 
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 
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 
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 
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 
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