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