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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#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
 62struct 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
 73struct 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
 85static inline struct imx_timer *to_imx_timer(struct clock_event_device *ced)
 86{
 87	return container_of(ced, struct imx_timer, ced);
 88}
 89
 90static 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
 99static 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
105static 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
114static 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
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#define imx6dl_gpt_irq_acknowledge imx31_gpt_irq_acknowledge
136
137static void __iomem *sched_clock_reg;
138
139static 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)
145static struct delay_timer imx_delay_timer;
146
147static unsigned long imx_read_current_timer(void)
148{
149	return readl_relaxed(sched_clock_reg);
150}
151#endif
152
153static 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
173static 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
187static 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
202static 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
224static 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 */
258static 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
273static 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
298static 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
307static 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
320static 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
337static 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
348static 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
359static 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
370static 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
381static 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
429void __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
448static 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
488static int __init imx1_timer_init_dt(struct device_node *np)
489{
490	return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
491}
492
493static int __init imx21_timer_init_dt(struct device_node *np)
494{
495	return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
496}
497
498static 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
514static int __init imx6dl_timer_init_dt(struct device_node *np)
515{
516	return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
517}
518
519TIMER_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
520TIMER_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
521TIMER_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
522TIMER_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
523TIMER_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
524TIMER_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
525TIMER_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
526TIMER_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
527TIMER_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
528TIMER_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
529TIMER_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
530TIMER_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);