xref: /linux/drivers/clocksource/ingenic-timer.c (revision bd4af432cc71b5fbfe4833510359a6ad3ada250d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * JZ47xx SoCs TCU IRQ driver
4  * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
5  */
6 
7 #include <linux/bitops.h>
8 #include <linux/clk.h>
9 #include <linux/clockchips.h>
10 #include <linux/clocksource.h>
11 #include <linux/interrupt.h>
12 #include <linux/mfd/ingenic-tcu.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 #include <linux/of_irq.h>
17 #include <linux/of_platform.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 #include <linux/sched_clock.h>
21 
22 #include <dt-bindings/clock/ingenic,tcu.h>
23 
24 struct ingenic_soc_info {
25 	unsigned int num_channels;
26 };
27 
28 struct ingenic_tcu {
29 	struct regmap *map;
30 	struct clk *timer_clk, *cs_clk;
31 	unsigned int timer_channel, cs_channel;
32 	struct clock_event_device cevt;
33 	struct clocksource cs;
34 	char name[4];
35 	unsigned long pwm_channels_mask;
36 };
37 
38 static struct ingenic_tcu *ingenic_tcu;
39 
40 static u64 notrace ingenic_tcu_timer_read(void)
41 {
42 	struct ingenic_tcu *tcu = ingenic_tcu;
43 	unsigned int count;
44 
45 	regmap_read(tcu->map, TCU_REG_TCNTc(tcu->cs_channel), &count);
46 
47 	return count;
48 }
49 
50 static u64 notrace ingenic_tcu_timer_cs_read(struct clocksource *cs)
51 {
52 	return ingenic_tcu_timer_read();
53 }
54 
55 static inline struct ingenic_tcu *to_ingenic_tcu(struct clock_event_device *evt)
56 {
57 	return container_of(evt, struct ingenic_tcu, cevt);
58 }
59 
60 static int ingenic_tcu_cevt_set_state_shutdown(struct clock_event_device *evt)
61 {
62 	struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
63 
64 	regmap_write(tcu->map, TCU_REG_TECR, BIT(tcu->timer_channel));
65 
66 	return 0;
67 }
68 
69 static int ingenic_tcu_cevt_set_next(unsigned long next,
70 				     struct clock_event_device *evt)
71 {
72 	struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
73 
74 	if (next > 0xffff)
75 		return -EINVAL;
76 
77 	regmap_write(tcu->map, TCU_REG_TDFRc(tcu->timer_channel), next);
78 	regmap_write(tcu->map, TCU_REG_TCNTc(tcu->timer_channel), 0);
79 	regmap_write(tcu->map, TCU_REG_TESR, BIT(tcu->timer_channel));
80 
81 	return 0;
82 }
83 
84 static irqreturn_t ingenic_tcu_cevt_cb(int irq, void *dev_id)
85 {
86 	struct clock_event_device *evt = dev_id;
87 	struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
88 
89 	regmap_write(tcu->map, TCU_REG_TECR, BIT(tcu->timer_channel));
90 
91 	if (evt->event_handler)
92 		evt->event_handler(evt);
93 
94 	return IRQ_HANDLED;
95 }
96 
97 static struct clk * __init ingenic_tcu_get_clock(struct device_node *np, int id)
98 {
99 	struct of_phandle_args args;
100 
101 	args.np = np;
102 	args.args_count = 1;
103 	args.args[0] = id;
104 
105 	return of_clk_get_from_provider(&args);
106 }
107 
108 static int __init ingenic_tcu_timer_init(struct device_node *np,
109 					 struct ingenic_tcu *tcu)
110 {
111 	unsigned int timer_virq, channel = tcu->timer_channel;
112 	struct irq_domain *domain;
113 	unsigned long rate;
114 	int err;
115 
116 	tcu->timer_clk = ingenic_tcu_get_clock(np, channel);
117 	if (IS_ERR(tcu->timer_clk))
118 		return PTR_ERR(tcu->timer_clk);
119 
120 	err = clk_prepare_enable(tcu->timer_clk);
121 	if (err)
122 		goto err_clk_put;
123 
124 	rate = clk_get_rate(tcu->timer_clk);
125 	if (!rate) {
126 		err = -EINVAL;
127 		goto err_clk_disable;
128 	}
129 
130 	domain = irq_find_host(np);
131 	if (!domain) {
132 		err = -ENODEV;
133 		goto err_clk_disable;
134 	}
135 
136 	timer_virq = irq_create_mapping(domain, channel);
137 	if (!timer_virq) {
138 		err = -EINVAL;
139 		goto err_clk_disable;
140 	}
141 
142 	snprintf(tcu->name, sizeof(tcu->name), "TCU");
143 
144 	err = request_irq(timer_virq, ingenic_tcu_cevt_cb, IRQF_TIMER,
145 			  tcu->name, &tcu->cevt);
146 	if (err)
147 		goto err_irq_dispose_mapping;
148 
149 	tcu->cevt.cpumask = cpumask_of(smp_processor_id());
150 	tcu->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
151 	tcu->cevt.name = tcu->name;
152 	tcu->cevt.rating = 200;
153 	tcu->cevt.set_state_shutdown = ingenic_tcu_cevt_set_state_shutdown;
154 	tcu->cevt.set_next_event = ingenic_tcu_cevt_set_next;
155 
156 	clockevents_config_and_register(&tcu->cevt, rate, 10, 0xffff);
157 
158 	return 0;
159 
160 err_irq_dispose_mapping:
161 	irq_dispose_mapping(timer_virq);
162 err_clk_disable:
163 	clk_disable_unprepare(tcu->timer_clk);
164 err_clk_put:
165 	clk_put(tcu->timer_clk);
166 	return err;
167 }
168 
169 static int __init ingenic_tcu_clocksource_init(struct device_node *np,
170 					       struct ingenic_tcu *tcu)
171 {
172 	unsigned int channel = tcu->cs_channel;
173 	struct clocksource *cs = &tcu->cs;
174 	unsigned long rate;
175 	int err;
176 
177 	tcu->cs_clk = ingenic_tcu_get_clock(np, channel);
178 	if (IS_ERR(tcu->cs_clk))
179 		return PTR_ERR(tcu->cs_clk);
180 
181 	err = clk_prepare_enable(tcu->cs_clk);
182 	if (err)
183 		goto err_clk_put;
184 
185 	rate = clk_get_rate(tcu->cs_clk);
186 	if (!rate) {
187 		err = -EINVAL;
188 		goto err_clk_disable;
189 	}
190 
191 	/* Reset channel */
192 	regmap_update_bits(tcu->map, TCU_REG_TCSRc(channel),
193 			   0xffff & ~TCU_TCSR_RESERVED_BITS, 0);
194 
195 	/* Reset counter */
196 	regmap_write(tcu->map, TCU_REG_TDFRc(channel), 0xffff);
197 	regmap_write(tcu->map, TCU_REG_TCNTc(channel), 0);
198 
199 	/* Enable channel */
200 	regmap_write(tcu->map, TCU_REG_TESR, BIT(channel));
201 
202 	cs->name = "ingenic-timer";
203 	cs->rating = 200;
204 	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
205 	cs->mask = CLOCKSOURCE_MASK(16);
206 	cs->read = ingenic_tcu_timer_cs_read;
207 
208 	err = clocksource_register_hz(cs, rate);
209 	if (err)
210 		goto err_clk_disable;
211 
212 	return 0;
213 
214 err_clk_disable:
215 	clk_disable_unprepare(tcu->cs_clk);
216 err_clk_put:
217 	clk_put(tcu->cs_clk);
218 	return err;
219 }
220 
221 static const struct ingenic_soc_info jz4740_soc_info = {
222 	.num_channels = 8,
223 };
224 
225 static const struct ingenic_soc_info jz4725b_soc_info = {
226 	.num_channels = 6,
227 };
228 
229 static const struct of_device_id ingenic_tcu_of_match[] = {
230 	{ .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
231 	{ .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
232 	{ .compatible = "ingenic,jz4770-tcu", .data = &jz4740_soc_info, },
233 	{ .compatible = "ingenic,x1000-tcu", .data = &jz4740_soc_info, },
234 	{ /* sentinel */ }
235 };
236 
237 static int __init ingenic_tcu_init(struct device_node *np)
238 {
239 	const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
240 	const struct ingenic_soc_info *soc_info = id->data;
241 	struct ingenic_tcu *tcu;
242 	struct regmap *map;
243 	long rate;
244 	int ret;
245 
246 	of_node_clear_flag(np, OF_POPULATED);
247 
248 	map = device_node_to_regmap(np);
249 	if (IS_ERR(map))
250 		return PTR_ERR(map);
251 
252 	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
253 	if (!tcu)
254 		return -ENOMEM;
255 
256 	/* Enable all TCU channels for PWM use by default except channels 0/1 */
257 	tcu->pwm_channels_mask = GENMASK(soc_info->num_channels - 1, 2);
258 	of_property_read_u32(np, "ingenic,pwm-channels-mask",
259 			     (u32 *)&tcu->pwm_channels_mask);
260 
261 	/* Verify that we have at least two free channels */
262 	if (hweight8(tcu->pwm_channels_mask) > soc_info->num_channels - 2) {
263 		pr_crit("%s: Invalid PWM channel mask: 0x%02lx\n", __func__,
264 			tcu->pwm_channels_mask);
265 		ret = -EINVAL;
266 		goto err_free_ingenic_tcu;
267 	}
268 
269 	tcu->map = map;
270 	ingenic_tcu = tcu;
271 
272 	tcu->timer_channel = find_first_zero_bit(&tcu->pwm_channels_mask,
273 						 soc_info->num_channels);
274 	tcu->cs_channel = find_next_zero_bit(&tcu->pwm_channels_mask,
275 					     soc_info->num_channels,
276 					     tcu->timer_channel + 1);
277 
278 	ret = ingenic_tcu_clocksource_init(np, tcu);
279 	if (ret) {
280 		pr_crit("%s: Unable to init clocksource: %d\n", __func__, ret);
281 		goto err_free_ingenic_tcu;
282 	}
283 
284 	ret = ingenic_tcu_timer_init(np, tcu);
285 	if (ret)
286 		goto err_tcu_clocksource_cleanup;
287 
288 	/* Register the sched_clock at the end as there's no way to undo it */
289 	rate = clk_get_rate(tcu->cs_clk);
290 	sched_clock_register(ingenic_tcu_timer_read, 16, rate);
291 
292 	return 0;
293 
294 err_tcu_clocksource_cleanup:
295 	clocksource_unregister(&tcu->cs);
296 	clk_disable_unprepare(tcu->cs_clk);
297 	clk_put(tcu->cs_clk);
298 err_free_ingenic_tcu:
299 	kfree(tcu);
300 	return ret;
301 }
302 
303 TIMER_OF_DECLARE(jz4740_tcu_intc,  "ingenic,jz4740-tcu",  ingenic_tcu_init);
304 TIMER_OF_DECLARE(jz4725b_tcu_intc, "ingenic,jz4725b-tcu", ingenic_tcu_init);
305 TIMER_OF_DECLARE(jz4770_tcu_intc,  "ingenic,jz4770-tcu",  ingenic_tcu_init);
306 TIMER_OF_DECLARE(x1000_tcu_intc,  "ingenic,x1000-tcu",  ingenic_tcu_init);
307 
308 static int __init ingenic_tcu_probe(struct platform_device *pdev)
309 {
310 	platform_set_drvdata(pdev, ingenic_tcu);
311 
312 	return 0;
313 }
314 
315 static int __maybe_unused ingenic_tcu_suspend(struct device *dev)
316 {
317 	struct ingenic_tcu *tcu = dev_get_drvdata(dev);
318 
319 	clk_disable(tcu->cs_clk);
320 	clk_disable(tcu->timer_clk);
321 	return 0;
322 }
323 
324 static int __maybe_unused ingenic_tcu_resume(struct device *dev)
325 {
326 	struct ingenic_tcu *tcu = dev_get_drvdata(dev);
327 	int ret;
328 
329 	ret = clk_enable(tcu->timer_clk);
330 	if (ret)
331 		return ret;
332 
333 	ret = clk_enable(tcu->cs_clk);
334 	if (ret) {
335 		clk_disable(tcu->timer_clk);
336 		return ret;
337 	}
338 
339 	return 0;
340 }
341 
342 static const struct dev_pm_ops __maybe_unused ingenic_tcu_pm_ops = {
343 	/* _noirq: We want the TCU clocks to be gated last / ungated first */
344 	.suspend_noirq = ingenic_tcu_suspend,
345 	.resume_noirq  = ingenic_tcu_resume,
346 };
347 
348 static struct platform_driver ingenic_tcu_driver = {
349 	.driver = {
350 		.name	= "ingenic-tcu-timer",
351 #ifdef CONFIG_PM_SLEEP
352 		.pm	= &ingenic_tcu_pm_ops,
353 #endif
354 		.of_match_table = ingenic_tcu_of_match,
355 	},
356 };
357 builtin_platform_driver_probe(ingenic_tcu_driver, ingenic_tcu_probe);
358