1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (C) 2000-2001 Deep Blue Solutions
4 // Copyright (C) 2002 Shane Nay (shane@minirl.com)
5 // Copyright (C) 2006-2007 Pavel Pisa (ppisa@pikron.com)
6 // Copyright (C) 2008 Juergen Beisert (kernel@pengutronix.de)
7
8 #include <linux/interrupt.h>
9 #include <linux/irq.h>
10 #include <linux/clockchips.h>
11 #include <linux/clk.h>
12 #include <linux/delay.h>
13 #include <linux/err.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 #include <soc/imx/timer.h>
20
21 /*
22 * There are 4 versions of the timer hardware on Freescale MXC hardware.
23 * - MX1/MXL
24 * - MX21, MX27.
25 * - MX25, MX31, MX35, MX37, MX51, MX6Q(rev1.0)
26 * - MX6DL, MX6SX, MX6Q(rev1.1+)
27 */
28
29 /* defines common for all i.MX */
30 #define MXC_TCTL 0x00
31 #define MXC_TCTL_TEN (1 << 0) /* Enable module */
32 #define MXC_TPRER 0x04
33
34 /* MX1, MX21, MX27 */
35 #define MX1_2_TCTL_CLK_PCLK1 (1 << 1)
36 #define MX1_2_TCTL_IRQEN (1 << 4)
37 #define MX1_2_TCTL_FRR (1 << 8)
38 #define MX1_2_TCMP 0x08
39 #define MX1_2_TCN 0x10
40 #define MX1_2_TSTAT 0x14
41
42 /* MX21, MX27 */
43 #define MX2_TSTAT_CAPT (1 << 1)
44 #define MX2_TSTAT_COMP (1 << 0)
45
46 /* MX31, MX35, MX25, MX5, MX6 */
47 #define V2_TCTL_WAITEN (1 << 3) /* Wait enable mode */
48 #define V2_TCTL_CLK_IPG (1 << 6)
49 #define V2_TCTL_CLK_PER (2 << 6)
50 #define V2_TCTL_CLK_OSC_DIV8 (5 << 6)
51 #define V2_TCTL_FRR (1 << 9)
52 #define V2_TCTL_24MEN (1 << 10)
53 #define V2_TPRER_PRE24M 12
54 #define V2_IR 0x0c
55 #define V2_TSTAT 0x08
56 #define V2_TSTAT_OF1 (1 << 0)
57 #define V2_TCN 0x24
58 #define V2_TCMP 0x10
59
60 #define V2_TIMER_RATE_OSC_DIV8 3000000
61
62 struct imx_timer {
63 enum imx_gpt_type type;
64 void __iomem *base;
65 int irq;
66 struct clk *clk_per;
67 struct clk *clk_ipg;
68 const struct imx_gpt_data *gpt;
69 struct clock_event_device ced;
70 struct irqaction act;
71 };
72
73 struct imx_gpt_data {
74 int reg_tstat;
75 int reg_tcn;
76 int reg_tcmp;
77 void (*gpt_setup_tctl)(struct imx_timer *imxtm);
78 void (*gpt_irq_enable)(struct imx_timer *imxtm);
79 void (*gpt_irq_disable)(struct imx_timer *imxtm);
80 void (*gpt_irq_acknowledge)(struct imx_timer *imxtm);
81 int (*set_next_event)(unsigned long evt,
82 struct clock_event_device *ced);
83 };
84
to_imx_timer(struct clock_event_device * ced)85 static inline struct imx_timer *to_imx_timer(struct clock_event_device *ced)
86 {
87 return container_of(ced, struct imx_timer, ced);
88 }
89
imx1_gpt_irq_disable(struct imx_timer * imxtm)90 static void imx1_gpt_irq_disable(struct imx_timer *imxtm)
91 {
92 unsigned int tmp;
93
94 tmp = readl_relaxed(imxtm->base + MXC_TCTL);
95 writel_relaxed(tmp & ~MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
96 }
97 #define imx21_gpt_irq_disable imx1_gpt_irq_disable
98
imx31_gpt_irq_disable(struct imx_timer * imxtm)99 static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
100 {
101 writel_relaxed(0, imxtm->base + V2_IR);
102 }
103 #define imx6dl_gpt_irq_disable imx31_gpt_irq_disable
104
imx1_gpt_irq_enable(struct imx_timer * imxtm)105 static void imx1_gpt_irq_enable(struct imx_timer *imxtm)
106 {
107 unsigned int tmp;
108
109 tmp = readl_relaxed(imxtm->base + MXC_TCTL);
110 writel_relaxed(tmp | MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
111 }
112 #define imx21_gpt_irq_enable imx1_gpt_irq_enable
113
imx31_gpt_irq_enable(struct imx_timer * imxtm)114 static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
115 {
116 writel_relaxed(1<<0, imxtm->base + V2_IR);
117 }
118 #define imx6dl_gpt_irq_enable imx31_gpt_irq_enable
119
imx1_gpt_irq_acknowledge(struct imx_timer * imxtm)120 static void imx1_gpt_irq_acknowledge(struct imx_timer *imxtm)
121 {
122 writel_relaxed(0, imxtm->base + MX1_2_TSTAT);
123 }
124
imx21_gpt_irq_acknowledge(struct imx_timer * imxtm)125 static void imx21_gpt_irq_acknowledge(struct imx_timer *imxtm)
126 {
127 writel_relaxed(MX2_TSTAT_CAPT | MX2_TSTAT_COMP,
128 imxtm->base + MX1_2_TSTAT);
129 }
130
imx31_gpt_irq_acknowledge(struct imx_timer * imxtm)131 static void imx31_gpt_irq_acknowledge(struct imx_timer *imxtm)
132 {
133 writel_relaxed(V2_TSTAT_OF1, imxtm->base + V2_TSTAT);
134 }
135 #define imx6dl_gpt_irq_acknowledge imx31_gpt_irq_acknowledge
136
137 static void __iomem *sched_clock_reg;
138
mxc_read_sched_clock(void)139 static u64 notrace mxc_read_sched_clock(void)
140 {
141 return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
142 }
143
144 #if defined(CONFIG_ARM)
145 static struct delay_timer imx_delay_timer;
146
imx_read_current_timer(void)147 static unsigned long imx_read_current_timer(void)
148 {
149 return readl_relaxed(sched_clock_reg);
150 }
151 #endif
152
mxc_clocksource_init(struct imx_timer * imxtm)153 static int __init mxc_clocksource_init(struct imx_timer *imxtm)
154 {
155 unsigned int c = clk_get_rate(imxtm->clk_per);
156 void __iomem *reg = imxtm->base + imxtm->gpt->reg_tcn;
157
158 #if defined(CONFIG_ARM)
159 imx_delay_timer.read_current_timer = &imx_read_current_timer;
160 imx_delay_timer.freq = c;
161 register_current_timer_delay(&imx_delay_timer);
162 #endif
163
164 sched_clock_reg = reg;
165
166 sched_clock_register(mxc_read_sched_clock, 32, c);
167 return clocksource_mmio_init(reg, "mxc_timer1", c, 200, 32,
168 clocksource_mmio_readl_up);
169 }
170
171 /* clock event */
172
mx1_2_set_next_event(unsigned long evt,struct clock_event_device * ced)173 static int mx1_2_set_next_event(unsigned long evt,
174 struct clock_event_device *ced)
175 {
176 struct imx_timer *imxtm = to_imx_timer(ced);
177 unsigned long tcmp;
178
179 tcmp = readl_relaxed(imxtm->base + MX1_2_TCN) + evt;
180
181 writel_relaxed(tcmp, imxtm->base + MX1_2_TCMP);
182
183 return (int)(tcmp - readl_relaxed(imxtm->base + MX1_2_TCN)) < 0 ?
184 -ETIME : 0;
185 }
186
v2_set_next_event(unsigned long evt,struct clock_event_device * ced)187 static int v2_set_next_event(unsigned long evt,
188 struct clock_event_device *ced)
189 {
190 struct imx_timer *imxtm = to_imx_timer(ced);
191 unsigned long tcmp;
192
193 tcmp = readl_relaxed(imxtm->base + V2_TCN) + evt;
194
195 writel_relaxed(tcmp, imxtm->base + V2_TCMP);
196
197 return evt < 0x7fffffff &&
198 (int)(tcmp - readl_relaxed(imxtm->base + V2_TCN)) < 0 ?
199 -ETIME : 0;
200 }
201
mxc_shutdown(struct clock_event_device * ced)202 static int mxc_shutdown(struct clock_event_device *ced)
203 {
204 struct imx_timer *imxtm = to_imx_timer(ced);
205 u32 tcn;
206
207 /* Disable interrupt in GPT module */
208 imxtm->gpt->gpt_irq_disable(imxtm);
209
210 tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
211 /* Set event time into far-far future */
212 writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
213
214 /* Clear pending interrupt */
215 imxtm->gpt->gpt_irq_acknowledge(imxtm);
216
217 #ifdef DEBUG
218 printk(KERN_INFO "%s: changing mode\n", __func__);
219 #endif /* DEBUG */
220
221 return 0;
222 }
223
mxc_set_oneshot(struct clock_event_device * ced)224 static int mxc_set_oneshot(struct clock_event_device *ced)
225 {
226 struct imx_timer *imxtm = to_imx_timer(ced);
227
228 /* Disable interrupt in GPT module */
229 imxtm->gpt->gpt_irq_disable(imxtm);
230
231 if (!clockevent_state_oneshot(ced)) {
232 u32 tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
233 /* Set event time into far-far future */
234 writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
235
236 /* Clear pending interrupt */
237 imxtm->gpt->gpt_irq_acknowledge(imxtm);
238 }
239
240 #ifdef DEBUG
241 printk(KERN_INFO "%s: changing mode\n", __func__);
242 #endif /* DEBUG */
243
244 /*
245 * Do not put overhead of interrupt enable/disable into
246 * mxc_set_next_event(), the core has about 4 minutes
247 * to call mxc_set_next_event() or shutdown clock after
248 * mode switching
249 */
250 imxtm->gpt->gpt_irq_enable(imxtm);
251
252 return 0;
253 }
254
255 /*
256 * IRQ handler for the timer
257 */
mxc_timer_interrupt(int irq,void * dev_id)258 static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
259 {
260 struct clock_event_device *ced = dev_id;
261 struct imx_timer *imxtm = to_imx_timer(ced);
262 uint32_t tstat;
263
264 tstat = readl_relaxed(imxtm->base + imxtm->gpt->reg_tstat);
265
266 imxtm->gpt->gpt_irq_acknowledge(imxtm);
267
268 ced->event_handler(ced);
269
270 return IRQ_HANDLED;
271 }
272
mxc_clockevent_init(struct imx_timer * imxtm)273 static int __init mxc_clockevent_init(struct imx_timer *imxtm)
274 {
275 struct clock_event_device *ced = &imxtm->ced;
276 struct irqaction *act = &imxtm->act;
277
278 ced->name = "mxc_timer1";
279 ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ;
280 ced->set_state_shutdown = mxc_shutdown;
281 ced->set_state_oneshot = mxc_set_oneshot;
282 ced->tick_resume = mxc_shutdown;
283 ced->set_next_event = imxtm->gpt->set_next_event;
284 ced->rating = 200;
285 ced->cpumask = cpumask_of(0);
286 ced->irq = imxtm->irq;
287 clockevents_config_and_register(ced, clk_get_rate(imxtm->clk_per),
288 0xff, 0xfffffffe);
289
290 act->name = "i.MX Timer Tick";
291 act->flags = IRQF_TIMER | IRQF_IRQPOLL;
292 act->handler = mxc_timer_interrupt;
293 act->dev_id = ced;
294
295 return setup_irq(imxtm->irq, act);
296 }
297
imx1_gpt_setup_tctl(struct imx_timer * imxtm)298 static void imx1_gpt_setup_tctl(struct imx_timer *imxtm)
299 {
300 u32 tctl_val;
301
302 tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
303 writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
304 }
305 #define imx21_gpt_setup_tctl imx1_gpt_setup_tctl
306
imx31_gpt_setup_tctl(struct imx_timer * imxtm)307 static void imx31_gpt_setup_tctl(struct imx_timer *imxtm)
308 {
309 u32 tctl_val;
310
311 tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
312 if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8)
313 tctl_val |= V2_TCTL_CLK_OSC_DIV8;
314 else
315 tctl_val |= V2_TCTL_CLK_PER;
316
317 writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
318 }
319
imx6dl_gpt_setup_tctl(struct imx_timer * imxtm)320 static void imx6dl_gpt_setup_tctl(struct imx_timer *imxtm)
321 {
322 u32 tctl_val;
323
324 tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
325 if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8) {
326 tctl_val |= V2_TCTL_CLK_OSC_DIV8;
327 /* 24 / 8 = 3 MHz */
328 writel_relaxed(7 << V2_TPRER_PRE24M, imxtm->base + MXC_TPRER);
329 tctl_val |= V2_TCTL_24MEN;
330 } else {
331 tctl_val |= V2_TCTL_CLK_PER;
332 }
333
334 writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
335 }
336
337 static const struct imx_gpt_data imx1_gpt_data = {
338 .reg_tstat = MX1_2_TSTAT,
339 .reg_tcn = MX1_2_TCN,
340 .reg_tcmp = MX1_2_TCMP,
341 .gpt_irq_enable = imx1_gpt_irq_enable,
342 .gpt_irq_disable = imx1_gpt_irq_disable,
343 .gpt_irq_acknowledge = imx1_gpt_irq_acknowledge,
344 .gpt_setup_tctl = imx1_gpt_setup_tctl,
345 .set_next_event = mx1_2_set_next_event,
346 };
347
348 static const struct imx_gpt_data imx21_gpt_data = {
349 .reg_tstat = MX1_2_TSTAT,
350 .reg_tcn = MX1_2_TCN,
351 .reg_tcmp = MX1_2_TCMP,
352 .gpt_irq_enable = imx21_gpt_irq_enable,
353 .gpt_irq_disable = imx21_gpt_irq_disable,
354 .gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
355 .gpt_setup_tctl = imx21_gpt_setup_tctl,
356 .set_next_event = mx1_2_set_next_event,
357 };
358
359 static const struct imx_gpt_data imx31_gpt_data = {
360 .reg_tstat = V2_TSTAT,
361 .reg_tcn = V2_TCN,
362 .reg_tcmp = V2_TCMP,
363 .gpt_irq_enable = imx31_gpt_irq_enable,
364 .gpt_irq_disable = imx31_gpt_irq_disable,
365 .gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
366 .gpt_setup_tctl = imx31_gpt_setup_tctl,
367 .set_next_event = v2_set_next_event,
368 };
369
370 static const struct imx_gpt_data imx6dl_gpt_data = {
371 .reg_tstat = V2_TSTAT,
372 .reg_tcn = V2_TCN,
373 .reg_tcmp = V2_TCMP,
374 .gpt_irq_enable = imx6dl_gpt_irq_enable,
375 .gpt_irq_disable = imx6dl_gpt_irq_disable,
376 .gpt_irq_acknowledge = imx6dl_gpt_irq_acknowledge,
377 .gpt_setup_tctl = imx6dl_gpt_setup_tctl,
378 .set_next_event = v2_set_next_event,
379 };
380
_mxc_timer_init(struct imx_timer * imxtm)381 static int __init _mxc_timer_init(struct imx_timer *imxtm)
382 {
383 int ret;
384
385 switch (imxtm->type) {
386 case GPT_TYPE_IMX1:
387 imxtm->gpt = &imx1_gpt_data;
388 break;
389 case GPT_TYPE_IMX21:
390 imxtm->gpt = &imx21_gpt_data;
391 break;
392 case GPT_TYPE_IMX31:
393 imxtm->gpt = &imx31_gpt_data;
394 break;
395 case GPT_TYPE_IMX6DL:
396 imxtm->gpt = &imx6dl_gpt_data;
397 break;
398 default:
399 return -EINVAL;
400 }
401
402 if (IS_ERR(imxtm->clk_per)) {
403 pr_err("i.MX timer: unable to get clk\n");
404 return PTR_ERR(imxtm->clk_per);
405 }
406
407 if (!IS_ERR(imxtm->clk_ipg))
408 clk_prepare_enable(imxtm->clk_ipg);
409
410 clk_prepare_enable(imxtm->clk_per);
411
412 /*
413 * Initialise to a known state (all timers off, and timing reset)
414 */
415
416 writel_relaxed(0, imxtm->base + MXC_TCTL);
417 writel_relaxed(0, imxtm->base + MXC_TPRER); /* see datasheet note */
418
419 imxtm->gpt->gpt_setup_tctl(imxtm);
420
421 /* init and register the timer to the framework */
422 ret = mxc_clocksource_init(imxtm);
423 if (ret)
424 return ret;
425
426 return mxc_clockevent_init(imxtm);
427 }
428
mxc_timer_init(unsigned long pbase,int irq,enum imx_gpt_type type)429 void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
430 {
431 struct imx_timer *imxtm;
432
433 imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
434 BUG_ON(!imxtm);
435
436 imxtm->clk_per = clk_get_sys("imx-gpt.0", "per");
437 imxtm->clk_ipg = clk_get_sys("imx-gpt.0", "ipg");
438
439 imxtm->base = ioremap(pbase, SZ_4K);
440 BUG_ON(!imxtm->base);
441
442 imxtm->type = type;
443 imxtm->irq = irq;
444
445 _mxc_timer_init(imxtm);
446 }
447
mxc_timer_init_dt(struct device_node * np,enum imx_gpt_type type)448 static int __init mxc_timer_init_dt(struct device_node *np, enum imx_gpt_type type)
449 {
450 struct imx_timer *imxtm;
451 static int initialized;
452 int ret;
453
454 /* Support one instance only */
455 if (initialized)
456 return 0;
457
458 imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
459 if (!imxtm)
460 return -ENOMEM;
461
462 imxtm->base = of_iomap(np, 0);
463 if (!imxtm->base)
464 return -ENXIO;
465
466 imxtm->irq = irq_of_parse_and_map(np, 0);
467 if (imxtm->irq <= 0)
468 return -EINVAL;
469
470 imxtm->clk_ipg = of_clk_get_by_name(np, "ipg");
471
472 /* Try osc_per first, and fall back to per otherwise */
473 imxtm->clk_per = of_clk_get_by_name(np, "osc_per");
474 if (IS_ERR(imxtm->clk_per))
475 imxtm->clk_per = of_clk_get_by_name(np, "per");
476
477 imxtm->type = type;
478
479 ret = _mxc_timer_init(imxtm);
480 if (ret)
481 return ret;
482
483 initialized = 1;
484
485 return 0;
486 }
487
imx1_timer_init_dt(struct device_node * np)488 static int __init imx1_timer_init_dt(struct device_node *np)
489 {
490 return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
491 }
492
imx21_timer_init_dt(struct device_node * np)493 static int __init imx21_timer_init_dt(struct device_node *np)
494 {
495 return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
496 }
497
imx31_timer_init_dt(struct device_node * np)498 static int __init imx31_timer_init_dt(struct device_node *np)
499 {
500 enum imx_gpt_type type = GPT_TYPE_IMX31;
501
502 /*
503 * We were using the same compatible string for i.MX6Q/D and i.MX6DL/S
504 * GPT device, while they actually have different programming model.
505 * This is a workaround to keep the existing i.MX6DL/S DTBs continue
506 * working with the new kernel.
507 */
508 if (of_machine_is_compatible("fsl,imx6dl"))
509 type = GPT_TYPE_IMX6DL;
510
511 return mxc_timer_init_dt(np, type);
512 }
513
imx6dl_timer_init_dt(struct device_node * np)514 static int __init imx6dl_timer_init_dt(struct device_node *np)
515 {
516 return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
517 }
518
519 TIMER_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
520 TIMER_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
521 TIMER_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
522 TIMER_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
523 TIMER_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
524 TIMER_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
525 TIMER_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
526 TIMER_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
527 TIMER_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
528 TIMER_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
529 TIMER_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
530 TIMER_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);
531
