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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Allwinner SoCs hstimer driver.
4 *
5 * Copyright (C) 2013 Maxime Ripard
6 *
7 * Maxime Ripard <maxime.ripard@free-electrons.com>
8 */
9
10#include <linux/clk.h>
11#include <linux/clockchips.h>
12#include <linux/clocksource.h>
13#include <linux/delay.h>
14#include <linux/interrupt.h>
15#include <linux/irq.h>
16#include <linux/irqreturn.h>
17#include <linux/reset.h>
18#include <linux/slab.h>
19#include <linux/of.h>
20#include <linux/of_address.h>
21#include <linux/of_irq.h>
22
23#define TIMER_IRQ_EN_REG 0x00
24#define TIMER_IRQ_EN(val) BIT(val)
25#define TIMER_IRQ_ST_REG 0x04
26#define TIMER_CTL_REG(val) (0x20 * (val) + 0x10)
27#define TIMER_CTL_ENABLE BIT(0)
28#define TIMER_CTL_RELOAD BIT(1)
29#define TIMER_CTL_CLK_PRES(val) (((val) & 0x7) << 4)
30#define TIMER_CTL_ONESHOT BIT(7)
31#define TIMER_INTVAL_LO_REG(val) (0x20 * (val) + 0x14)
32#define TIMER_INTVAL_HI_REG(val) (0x20 * (val) + 0x18)
33#define TIMER_CNTVAL_LO_REG(val) (0x20 * (val) + 0x1c)
34#define TIMER_CNTVAL_HI_REG(val) (0x20 * (val) + 0x20)
35
36#define TIMER_SYNC_TICKS 3
37
38struct sun5i_timer {
39 void __iomem *base;
40 struct clk *clk;
41 struct notifier_block clk_rate_cb;
42 u32 ticks_per_jiffy;
43};
44
45#define to_sun5i_timer(x) \
46 container_of(x, struct sun5i_timer, clk_rate_cb)
47
48struct sun5i_timer_clksrc {
49 struct sun5i_timer timer;
50 struct clocksource clksrc;
51};
52
53#define to_sun5i_timer_clksrc(x) \
54 container_of(x, struct sun5i_timer_clksrc, clksrc)
55
56struct sun5i_timer_clkevt {
57 struct sun5i_timer timer;
58 struct clock_event_device clkevt;
59};
60
61#define to_sun5i_timer_clkevt(x) \
62 container_of(x, struct sun5i_timer_clkevt, clkevt)
63
64/*
65 * When we disable a timer, we need to wait at least for 2 cycles of
66 * the timer source clock. We will use for that the clocksource timer
67 * that is already setup and runs at the same frequency than the other
68 * timers, and we never will be disabled.
69 */
70static void sun5i_clkevt_sync(struct sun5i_timer_clkevt *ce)
71{
72 u32 old = readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1));
73
74 while ((old - readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1))) < TIMER_SYNC_TICKS)
75 cpu_relax();
76}
77
78static void sun5i_clkevt_time_stop(struct sun5i_timer_clkevt *ce, u8 timer)
79{
80 u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer));
81 writel(val & ~TIMER_CTL_ENABLE, ce->timer.base + TIMER_CTL_REG(timer));
82
83 sun5i_clkevt_sync(ce);
84}
85
86static void sun5i_clkevt_time_setup(struct sun5i_timer_clkevt *ce, u8 timer, u32 delay)
87{
88 writel(delay, ce->timer.base + TIMER_INTVAL_LO_REG(timer));
89}
90
91static void sun5i_clkevt_time_start(struct sun5i_timer_clkevt *ce, u8 timer, bool periodic)
92{
93 u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer));
94
95 if (periodic)
96 val &= ~TIMER_CTL_ONESHOT;
97 else
98 val |= TIMER_CTL_ONESHOT;
99
100 writel(val | TIMER_CTL_ENABLE | TIMER_CTL_RELOAD,
101 ce->timer.base + TIMER_CTL_REG(timer));
102}
103
104static int sun5i_clkevt_shutdown(struct clock_event_device *clkevt)
105{
106 struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt);
107
108 sun5i_clkevt_time_stop(ce, 0);
109 return 0;
110}
111
112static int sun5i_clkevt_set_oneshot(struct clock_event_device *clkevt)
113{
114 struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt);
115
116 sun5i_clkevt_time_stop(ce, 0);
117 sun5i_clkevt_time_start(ce, 0, false);
118 return 0;
119}
120
121static int sun5i_clkevt_set_periodic(struct clock_event_device *clkevt)
122{
123 struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt);
124
125 sun5i_clkevt_time_stop(ce, 0);
126 sun5i_clkevt_time_setup(ce, 0, ce->timer.ticks_per_jiffy);
127 sun5i_clkevt_time_start(ce, 0, true);
128 return 0;
129}
130
131static int sun5i_clkevt_next_event(unsigned long evt,
132 struct clock_event_device *clkevt)
133{
134 struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt);
135
136 sun5i_clkevt_time_stop(ce, 0);
137 sun5i_clkevt_time_setup(ce, 0, evt - TIMER_SYNC_TICKS);
138 sun5i_clkevt_time_start(ce, 0, false);
139
140 return 0;
141}
142
143static irqreturn_t sun5i_timer_interrupt(int irq, void *dev_id)
144{
145 struct sun5i_timer_clkevt *ce = dev_id;
146
147 writel(0x1, ce->timer.base + TIMER_IRQ_ST_REG);
148 ce->clkevt.event_handler(&ce->clkevt);
149
150 return IRQ_HANDLED;
151}
152
153static u64 sun5i_clksrc_read(struct clocksource *clksrc)
154{
155 struct sun5i_timer_clksrc *cs = to_sun5i_timer_clksrc(clksrc);
156
157 return ~readl(cs->timer.base + TIMER_CNTVAL_LO_REG(1));
158}
159
160static int sun5i_rate_cb_clksrc(struct notifier_block *nb,
161 unsigned long event, void *data)
162{
163 struct clk_notifier_data *ndata = data;
164 struct sun5i_timer *timer = to_sun5i_timer(nb);
165 struct sun5i_timer_clksrc *cs = container_of(timer, struct sun5i_timer_clksrc, timer);
166
167 switch (event) {
168 case PRE_RATE_CHANGE:
169 clocksource_unregister(&cs->clksrc);
170 break;
171
172 case POST_RATE_CHANGE:
173 clocksource_register_hz(&cs->clksrc, ndata->new_rate);
174 break;
175
176 default:
177 break;
178 }
179
180 return NOTIFY_DONE;
181}
182
183static int __init sun5i_setup_clocksource(struct device_node *node,
184 void __iomem *base,
185 struct clk *clk, int irq)
186{
187 struct sun5i_timer_clksrc *cs;
188 unsigned long rate;
189 int ret;
190
191 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
192 if (!cs)
193 return -ENOMEM;
194
195 ret = clk_prepare_enable(clk);
196 if (ret) {
197 pr_err("Couldn't enable parent clock\n");
198 goto err_free;
199 }
200
201 rate = clk_get_rate(clk);
202 if (!rate) {
203 pr_err("Couldn't get parent clock rate\n");
204 ret = -EINVAL;
205 goto err_disable_clk;
206 }
207
208 cs->timer.base = base;
209 cs->timer.clk = clk;
210 cs->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clksrc;
211 cs->timer.clk_rate_cb.next = NULL;
212
213 ret = clk_notifier_register(clk, &cs->timer.clk_rate_cb);
214 if (ret) {
215 pr_err("Unable to register clock notifier.\n");
216 goto err_disable_clk;
217 }
218
219 writel(~0, base + TIMER_INTVAL_LO_REG(1));
220 writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD,
221 base + TIMER_CTL_REG(1));
222
223 cs->clksrc.name = node->name;
224 cs->clksrc.rating = 340;
225 cs->clksrc.read = sun5i_clksrc_read;
226 cs->clksrc.mask = CLOCKSOURCE_MASK(32);
227 cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
228
229 ret = clocksource_register_hz(&cs->clksrc, rate);
230 if (ret) {
231 pr_err("Couldn't register clock source.\n");
232 goto err_remove_notifier;
233 }
234
235 return 0;
236
237err_remove_notifier:
238 clk_notifier_unregister(clk, &cs->timer.clk_rate_cb);
239err_disable_clk:
240 clk_disable_unprepare(clk);
241err_free:
242 kfree(cs);
243 return ret;
244}
245
246static int sun5i_rate_cb_clkevt(struct notifier_block *nb,
247 unsigned long event, void *data)
248{
249 struct clk_notifier_data *ndata = data;
250 struct sun5i_timer *timer = to_sun5i_timer(nb);
251 struct sun5i_timer_clkevt *ce = container_of(timer, struct sun5i_timer_clkevt, timer);
252
253 if (event == POST_RATE_CHANGE) {
254 clockevents_update_freq(&ce->clkevt, ndata->new_rate);
255 ce->timer.ticks_per_jiffy = DIV_ROUND_UP(ndata->new_rate, HZ);
256 }
257
258 return NOTIFY_DONE;
259}
260
261static int __init sun5i_setup_clockevent(struct device_node *node, void __iomem *base,
262 struct clk *clk, int irq)
263{
264 struct sun5i_timer_clkevt *ce;
265 unsigned long rate;
266 int ret;
267 u32 val;
268
269 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
270 if (!ce)
271 return -ENOMEM;
272
273 ret = clk_prepare_enable(clk);
274 if (ret) {
275 pr_err("Couldn't enable parent clock\n");
276 goto err_free;
277 }
278
279 rate = clk_get_rate(clk);
280 if (!rate) {
281 pr_err("Couldn't get parent clock rate\n");
282 ret = -EINVAL;
283 goto err_disable_clk;
284 }
285
286 ce->timer.base = base;
287 ce->timer.ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
288 ce->timer.clk = clk;
289 ce->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clkevt;
290 ce->timer.clk_rate_cb.next = NULL;
291
292 ret = clk_notifier_register(clk, &ce->timer.clk_rate_cb);
293 if (ret) {
294 pr_err("Unable to register clock notifier.\n");
295 goto err_disable_clk;
296 }
297
298 ce->clkevt.name = node->name;
299 ce->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
300 ce->clkevt.set_next_event = sun5i_clkevt_next_event;
301 ce->clkevt.set_state_shutdown = sun5i_clkevt_shutdown;
302 ce->clkevt.set_state_periodic = sun5i_clkevt_set_periodic;
303 ce->clkevt.set_state_oneshot = sun5i_clkevt_set_oneshot;
304 ce->clkevt.tick_resume = sun5i_clkevt_shutdown;
305 ce->clkevt.rating = 340;
306 ce->clkevt.irq = irq;
307 ce->clkevt.cpumask = cpu_possible_mask;
308
309 /* Enable timer0 interrupt */
310 val = readl(base + TIMER_IRQ_EN_REG);
311 writel(val | TIMER_IRQ_EN(0), base + TIMER_IRQ_EN_REG);
312
313 clockevents_config_and_register(&ce->clkevt, rate,
314 TIMER_SYNC_TICKS, 0xffffffff);
315
316 ret = request_irq(irq, sun5i_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
317 "sun5i_timer0", ce);
318 if (ret) {
319 pr_err("Unable to register interrupt\n");
320 goto err_remove_notifier;
321 }
322
323 return 0;
324
325err_remove_notifier:
326 clk_notifier_unregister(clk, &ce->timer.clk_rate_cb);
327err_disable_clk:
328 clk_disable_unprepare(clk);
329err_free:
330 kfree(ce);
331 return ret;
332}
333
334static int __init sun5i_timer_init(struct device_node *node)
335{
336 struct reset_control *rstc;
337 void __iomem *timer_base;
338 struct clk *clk;
339 int irq, ret;
340
341 timer_base = of_io_request_and_map(node, 0, of_node_full_name(node));
342 if (IS_ERR(timer_base)) {
343 pr_err("Can't map registers\n");
344 return PTR_ERR(timer_base);
345 }
346
347 irq = irq_of_parse_and_map(node, 0);
348 if (irq <= 0) {
349 pr_err("Can't parse IRQ\n");
350 return -EINVAL;
351 }
352
353 clk = of_clk_get(node, 0);
354 if (IS_ERR(clk)) {
355 pr_err("Can't get timer clock\n");
356 return PTR_ERR(clk);
357 }
358
359 rstc = of_reset_control_get(node, NULL);
360 if (!IS_ERR(rstc))
361 reset_control_deassert(rstc);
362
363 ret = sun5i_setup_clocksource(node, timer_base, clk, irq);
364 if (ret)
365 return ret;
366
367 return sun5i_setup_clockevent(node, timer_base, clk, irq);
368}
369TIMER_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer",
370 sun5i_timer_init);
371TIMER_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer",
372 sun5i_timer_init);
1/*
2 * Allwinner SoCs hstimer driver.
3 *
4 * Copyright (C) 2013 Maxime Ripard
5 *
6 * Maxime Ripard <maxime.ripard@free-electrons.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13#include <linux/clk.h>
14#include <linux/clockchips.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/irqreturn.h>
19#include <linux/sched_clock.h>
20#include <linux/of.h>
21#include <linux/of_address.h>
22#include <linux/of_irq.h>
23
24#define TIMER_IRQ_EN_REG 0x00
25#define TIMER_IRQ_EN(val) BIT(val)
26#define TIMER_IRQ_ST_REG 0x04
27#define TIMER_CTL_REG(val) (0x20 * (val) + 0x10)
28#define TIMER_CTL_ENABLE BIT(0)
29#define TIMER_CTL_RELOAD BIT(1)
30#define TIMER_CTL_CLK_PRES(val) (((val) & 0x7) << 4)
31#define TIMER_CTL_ONESHOT BIT(7)
32#define TIMER_INTVAL_LO_REG(val) (0x20 * (val) + 0x14)
33#define TIMER_INTVAL_HI_REG(val) (0x20 * (val) + 0x18)
34#define TIMER_CNTVAL_LO_REG(val) (0x20 * (val) + 0x1c)
35#define TIMER_CNTVAL_HI_REG(val) (0x20 * (val) + 0x20)
36
37#define TIMER_SYNC_TICKS 3
38
39static void __iomem *timer_base;
40static u32 ticks_per_jiffy;
41
42/*
43 * When we disable a timer, we need to wait at least for 2 cycles of
44 * the timer source clock. We will use for that the clocksource timer
45 * that is already setup and runs at the same frequency than the other
46 * timers, and we never will be disabled.
47 */
48static void sun5i_clkevt_sync(void)
49{
50 u32 old = readl(timer_base + TIMER_CNTVAL_LO_REG(1));
51
52 while ((old - readl(timer_base + TIMER_CNTVAL_LO_REG(1))) < TIMER_SYNC_TICKS)
53 cpu_relax();
54}
55
56static void sun5i_clkevt_time_stop(u8 timer)
57{
58 u32 val = readl(timer_base + TIMER_CTL_REG(timer));
59 writel(val & ~TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG(timer));
60
61 sun5i_clkevt_sync();
62}
63
64static void sun5i_clkevt_time_setup(u8 timer, u32 delay)
65{
66 writel(delay, timer_base + TIMER_INTVAL_LO_REG(timer));
67}
68
69static void sun5i_clkevt_time_start(u8 timer, bool periodic)
70{
71 u32 val = readl(timer_base + TIMER_CTL_REG(timer));
72
73 if (periodic)
74 val &= ~TIMER_CTL_ONESHOT;
75 else
76 val |= TIMER_CTL_ONESHOT;
77
78 writel(val | TIMER_CTL_ENABLE | TIMER_CTL_RELOAD,
79 timer_base + TIMER_CTL_REG(timer));
80}
81
82static void sun5i_clkevt_mode(enum clock_event_mode mode,
83 struct clock_event_device *clk)
84{
85 switch (mode) {
86 case CLOCK_EVT_MODE_PERIODIC:
87 sun5i_clkevt_time_stop(0);
88 sun5i_clkevt_time_setup(0, ticks_per_jiffy);
89 sun5i_clkevt_time_start(0, true);
90 break;
91 case CLOCK_EVT_MODE_ONESHOT:
92 sun5i_clkevt_time_stop(0);
93 sun5i_clkevt_time_start(0, false);
94 break;
95 case CLOCK_EVT_MODE_UNUSED:
96 case CLOCK_EVT_MODE_SHUTDOWN:
97 default:
98 sun5i_clkevt_time_stop(0);
99 break;
100 }
101}
102
103static int sun5i_clkevt_next_event(unsigned long evt,
104 struct clock_event_device *unused)
105{
106 sun5i_clkevt_time_stop(0);
107 sun5i_clkevt_time_setup(0, evt - TIMER_SYNC_TICKS);
108 sun5i_clkevt_time_start(0, false);
109
110 return 0;
111}
112
113static struct clock_event_device sun5i_clockevent = {
114 .name = "sun5i_tick",
115 .rating = 340,
116 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
117 .set_mode = sun5i_clkevt_mode,
118 .set_next_event = sun5i_clkevt_next_event,
119};
120
121
122static irqreturn_t sun5i_timer_interrupt(int irq, void *dev_id)
123{
124 struct clock_event_device *evt = (struct clock_event_device *)dev_id;
125
126 writel(0x1, timer_base + TIMER_IRQ_ST_REG);
127 evt->event_handler(evt);
128
129 return IRQ_HANDLED;
130}
131
132static struct irqaction sun5i_timer_irq = {
133 .name = "sun5i_timer0",
134 .flags = IRQF_TIMER | IRQF_IRQPOLL,
135 .handler = sun5i_timer_interrupt,
136 .dev_id = &sun5i_clockevent,
137};
138
139static u64 sun5i_timer_sched_read(void)
140{
141 return ~readl(timer_base + TIMER_CNTVAL_LO_REG(1));
142}
143
144static void __init sun5i_timer_init(struct device_node *node)
145{
146 unsigned long rate;
147 struct clk *clk;
148 int ret, irq;
149 u32 val;
150
151 timer_base = of_iomap(node, 0);
152 if (!timer_base)
153 panic("Can't map registers");
154
155 irq = irq_of_parse_and_map(node, 0);
156 if (irq <= 0)
157 panic("Can't parse IRQ");
158
159 clk = of_clk_get(node, 0);
160 if (IS_ERR(clk))
161 panic("Can't get timer clock");
162 clk_prepare_enable(clk);
163 rate = clk_get_rate(clk);
164
165 writel(~0, timer_base + TIMER_INTVAL_LO_REG(1));
166 writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD,
167 timer_base + TIMER_CTL_REG(1));
168
169 sched_clock_register(sun5i_timer_sched_read, 32, rate);
170 clocksource_mmio_init(timer_base + TIMER_CNTVAL_LO_REG(1), node->name,
171 rate, 340, 32, clocksource_mmio_readl_down);
172
173 ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
174
175 ret = setup_irq(irq, &sun5i_timer_irq);
176 if (ret)
177 pr_warn("failed to setup irq %d\n", irq);
178
179 /* Enable timer0 interrupt */
180 val = readl(timer_base + TIMER_IRQ_EN_REG);
181 writel(val | TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_EN_REG);
182
183 sun5i_clockevent.cpumask = cpu_possible_mask;
184 sun5i_clockevent.irq = irq;
185
186 clockevents_config_and_register(&sun5i_clockevent, rate,
187 TIMER_SYNC_TICKS, 0xffffffff);
188}
189CLOCKSOURCE_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer",
190 sun5i_timer_init);
191CLOCKSOURCE_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer",
192 sun5i_timer_init);