1 /*
2  * OMAP Dual-Mode Timers
3  *
4  * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
5  * Tarun Kanti DebBarma <tarun.kanti@ti.com>
6  * Thara Gopinath <thara@ti.com>
7  *
8  * Platform device conversion and hwmod support.
9  *
10  * Copyright (C) 2005 Nokia Corporation
11  * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
12  * PWM and clock framwork support by Timo Teras.
13  *
14  * This program is free software; you can redistribute it and/or modify it
15  * under the terms of the GNU General Public License as published by the
16  * Free Software Foundation; either version 2 of the License, or (at your
17  * option) any later version.
18  *
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
22  * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * You should have received a copy of the  GNU General Public License along
29  * with this program; if not, write  to the Free Software Foundation, Inc.,
30  * 675 Mass Ave, Cambridge, MA 02139, USA.
31  */
32 
33 #include <linux/delay.h>
34 #include <linux/io.h>
35 #include <linux/platform_device.h>
36 
37 #ifndef __CLOCKSOURCE_DMTIMER_H
38 #define __CLOCKSOURCE_DMTIMER_H
39 
40 /* clock sources */
41 #define OMAP_TIMER_SRC_SYS_CLK			0x00
42 #define OMAP_TIMER_SRC_32_KHZ			0x01
43 #define OMAP_TIMER_SRC_EXT_CLK			0x02
44 
45 /* timer interrupt enable bits */
46 #define OMAP_TIMER_INT_CAPTURE			(1 << 2)
47 #define OMAP_TIMER_INT_OVERFLOW			(1 << 1)
48 #define OMAP_TIMER_INT_MATCH			(1 << 0)
49 
50 /* trigger types */
51 #define OMAP_TIMER_TRIGGER_NONE			0x00
52 #define OMAP_TIMER_TRIGGER_OVERFLOW		0x01
53 #define OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE	0x02
54 
55 /* posted mode types */
56 #define OMAP_TIMER_NONPOSTED			0x00
57 #define OMAP_TIMER_POSTED			0x01
58 
59 /* timer capabilities used in hwmod database */
60 #define OMAP_TIMER_SECURE				0x80000000
61 #define OMAP_TIMER_ALWON				0x40000000
62 #define OMAP_TIMER_HAS_PWM				0x20000000
63 #define OMAP_TIMER_NEEDS_RESET				0x10000000
64 #define OMAP_TIMER_HAS_DSP_IRQ				0x08000000
65 
66 /*
67  * timer errata flags
68  *
69  * Errata i103/i767 impacts all OMAP3/4/5 devices including AM33xx. This
70  * errata prevents us from using posted mode on these devices, unless the
71  * timer counter register is never read. For more details please refer to
72  * the OMAP3/4/5 errata documents.
73  */
74 #define OMAP_TIMER_ERRATA_I103_I767			0x80000000
75 
76 struct timer_regs {
77 	u32 tidr;
78 	u32 tier;
79 	u32 twer;
80 	u32 tclr;
81 	u32 tcrr;
82 	u32 tldr;
83 	u32 ttrg;
84 	u32 twps;
85 	u32 tmar;
86 	u32 tcar1;
87 	u32 tsicr;
88 	u32 tcar2;
89 	u32 tpir;
90 	u32 tnir;
91 	u32 tcvr;
92 	u32 tocr;
93 	u32 towr;
94 };
95 
96 struct omap_dm_timer {
97 	int id;
98 	int irq;
99 	struct clk *fclk;
100 
101 	void __iomem	*io_base;
102 	void __iomem	*irq_stat;	/* TISR/IRQSTATUS interrupt status */
103 	void __iomem	*irq_ena;	/* irq enable */
104 	void __iomem	*irq_dis;	/* irq disable, only on v2 ip */
105 	void __iomem	*pend;		/* write pending */
106 	void __iomem	*func_base;	/* function register base */
107 
108 	atomic_t enabled;
109 	unsigned long rate;
110 	unsigned reserved:1;
111 	unsigned posted:1;
112 	struct timer_regs context;
113 	int revision;
114 	u32 capability;
115 	u32 errata;
116 	struct platform_device *pdev;
117 	struct list_head node;
118 	struct notifier_block nb;
119 };
120 
121 int omap_dm_timer_reserve_systimer(int id);
122 struct omap_dm_timer *omap_dm_timer_request_by_cap(u32 cap);
123 
124 int omap_dm_timer_get_irq(struct omap_dm_timer *timer);
125 
126 u32 omap_dm_timer_modify_idlect_mask(u32 inputmask);
127 
128 int omap_dm_timer_trigger(struct omap_dm_timer *timer);
129 
130 int omap_dm_timers_active(void);
131 
132 /*
133  * Do not use the defines below, they are not needed. They should be only
134  * used by dmtimer.c and sys_timer related code.
135  */
136 
137 /*
138  * The interrupt registers are different between v1 and v2 ip.
139  * These registers are offsets from timer->iobase.
140  */
141 #define OMAP_TIMER_ID_OFFSET		0x00
142 #define OMAP_TIMER_OCP_CFG_OFFSET	0x10
143 
144 #define OMAP_TIMER_V1_SYS_STAT_OFFSET	0x14
145 #define OMAP_TIMER_V1_STAT_OFFSET	0x18
146 #define OMAP_TIMER_V1_INT_EN_OFFSET	0x1c
147 
148 #define OMAP_TIMER_V2_IRQSTATUS_RAW	0x24
149 #define OMAP_TIMER_V2_IRQSTATUS		0x28
150 #define OMAP_TIMER_V2_IRQENABLE_SET	0x2c
151 #define OMAP_TIMER_V2_IRQENABLE_CLR	0x30
152 
153 /*
154  * The functional registers have a different base on v1 and v2 ip.
155  * These registers are offsets from timer->func_base. The func_base
156  * is samae as io_base for v1 and io_base + 0x14 for v2 ip.
157  *
158  */
159 #define OMAP_TIMER_V2_FUNC_OFFSET		0x14
160 
161 #define _OMAP_TIMER_WAKEUP_EN_OFFSET	0x20
162 #define _OMAP_TIMER_CTRL_OFFSET		0x24
163 #define		OMAP_TIMER_CTRL_GPOCFG		(1 << 14)
164 #define		OMAP_TIMER_CTRL_CAPTMODE	(1 << 13)
165 #define		OMAP_TIMER_CTRL_PT		(1 << 12)
166 #define		OMAP_TIMER_CTRL_TCM_LOWTOHIGH	(0x1 << 8)
167 #define		OMAP_TIMER_CTRL_TCM_HIGHTOLOW	(0x2 << 8)
168 #define		OMAP_TIMER_CTRL_TCM_BOTHEDGES	(0x3 << 8)
169 #define		OMAP_TIMER_CTRL_SCPWM		(1 << 7)
170 #define		OMAP_TIMER_CTRL_CE		(1 << 6) /* compare enable */
171 #define		OMAP_TIMER_CTRL_PRE		(1 << 5) /* prescaler enable */
172 #define		OMAP_TIMER_CTRL_PTV_SHIFT	2 /* prescaler value shift */
173 #define		OMAP_TIMER_CTRL_POSTED		(1 << 2)
174 #define		OMAP_TIMER_CTRL_AR		(1 << 1) /* auto-reload enable */
175 #define		OMAP_TIMER_CTRL_ST		(1 << 0) /* start timer */
176 #define _OMAP_TIMER_COUNTER_OFFSET	0x28
177 #define _OMAP_TIMER_LOAD_OFFSET		0x2c
178 #define _OMAP_TIMER_TRIGGER_OFFSET	0x30
179 #define _OMAP_TIMER_WRITE_PEND_OFFSET	0x34
180 #define		WP_NONE			0	/* no write pending bit */
181 #define		WP_TCLR			(1 << 0)
182 #define		WP_TCRR			(1 << 1)
183 #define		WP_TLDR			(1 << 2)
184 #define		WP_TTGR			(1 << 3)
185 #define		WP_TMAR			(1 << 4)
186 #define		WP_TPIR			(1 << 5)
187 #define		WP_TNIR			(1 << 6)
188 #define		WP_TCVR			(1 << 7)
189 #define		WP_TOCR			(1 << 8)
190 #define		WP_TOWR			(1 << 9)
191 #define _OMAP_TIMER_MATCH_OFFSET	0x38
192 #define _OMAP_TIMER_CAPTURE_OFFSET	0x3c
193 #define _OMAP_TIMER_IF_CTRL_OFFSET	0x40
194 #define _OMAP_TIMER_CAPTURE2_OFFSET		0x44	/* TCAR2, 34xx only */
195 #define _OMAP_TIMER_TICK_POS_OFFSET		0x48	/* TPIR, 34xx only */
196 #define _OMAP_TIMER_TICK_NEG_OFFSET		0x4c	/* TNIR, 34xx only */
197 #define _OMAP_TIMER_TICK_COUNT_OFFSET		0x50	/* TCVR, 34xx only */
198 #define _OMAP_TIMER_TICK_INT_MASK_SET_OFFSET	0x54	/* TOCR, 34xx only */
199 #define _OMAP_TIMER_TICK_INT_MASK_COUNT_OFFSET	0x58	/* TOWR, 34xx only */
200 
201 /* register offsets with the write pending bit encoded */
202 #define	WPSHIFT					16
203 
204 #define OMAP_TIMER_WAKEUP_EN_REG		(_OMAP_TIMER_WAKEUP_EN_OFFSET \
205 							| (WP_NONE << WPSHIFT))
206 
207 #define OMAP_TIMER_CTRL_REG			(_OMAP_TIMER_CTRL_OFFSET \
208 							| (WP_TCLR << WPSHIFT))
209 
210 #define OMAP_TIMER_COUNTER_REG			(_OMAP_TIMER_COUNTER_OFFSET \
211 							| (WP_TCRR << WPSHIFT))
212 
213 #define OMAP_TIMER_LOAD_REG			(_OMAP_TIMER_LOAD_OFFSET \
214 							| (WP_TLDR << WPSHIFT))
215 
216 #define OMAP_TIMER_TRIGGER_REG			(_OMAP_TIMER_TRIGGER_OFFSET \
217 							| (WP_TTGR << WPSHIFT))
218 
219 #define OMAP_TIMER_WRITE_PEND_REG		(_OMAP_TIMER_WRITE_PEND_OFFSET \
220 							| (WP_NONE << WPSHIFT))
221 
222 #define OMAP_TIMER_MATCH_REG			(_OMAP_TIMER_MATCH_OFFSET \
223 							| (WP_TMAR << WPSHIFT))
224 
225 #define OMAP_TIMER_CAPTURE_REG			(_OMAP_TIMER_CAPTURE_OFFSET \
226 							| (WP_NONE << WPSHIFT))
227 
228 #define OMAP_TIMER_IF_CTRL_REG			(_OMAP_TIMER_IF_CTRL_OFFSET \
229 							| (WP_NONE << WPSHIFT))
230 
231 #define OMAP_TIMER_CAPTURE2_REG			(_OMAP_TIMER_CAPTURE2_OFFSET \
232 							| (WP_NONE << WPSHIFT))
233 
234 #define OMAP_TIMER_TICK_POS_REG			(_OMAP_TIMER_TICK_POS_OFFSET \
235 							| (WP_TPIR << WPSHIFT))
236 
237 #define OMAP_TIMER_TICK_NEG_REG			(_OMAP_TIMER_TICK_NEG_OFFSET \
238 							| (WP_TNIR << WPSHIFT))
239 
240 #define OMAP_TIMER_TICK_COUNT_REG		(_OMAP_TIMER_TICK_COUNT_OFFSET \
241 							| (WP_TCVR << WPSHIFT))
242 
243 #define OMAP_TIMER_TICK_INT_MASK_SET_REG				\
244 		(_OMAP_TIMER_TICK_INT_MASK_SET_OFFSET | (WP_TOCR << WPSHIFT))
245 
246 #define OMAP_TIMER_TICK_INT_MASK_COUNT_REG				\
247 		(_OMAP_TIMER_TICK_INT_MASK_COUNT_OFFSET | (WP_TOWR << WPSHIFT))
248 
249 /*
250  * The below are inlined to optimize code size for system timers. Other code
251  * should not need these at all.
252  */
253 #if defined(CONFIG_ARCH_OMAP1) || defined(CONFIG_ARCH_OMAP2PLUS)
254 static inline u32 __omap_dm_timer_read(struct omap_dm_timer *timer, u32 reg,
255 						int posted)
256 {
257 	if (posted)
258 		while (readl_relaxed(timer->pend) & (reg >> WPSHIFT))
259 			cpu_relax();
260 
261 	return readl_relaxed(timer->func_base + (reg & 0xff));
262 }
263 
264 static inline void __omap_dm_timer_write(struct omap_dm_timer *timer,
265 					u32 reg, u32 val, int posted)
266 {
267 	if (posted)
268 		while (readl_relaxed(timer->pend) & (reg >> WPSHIFT))
269 			cpu_relax();
270 
271 	writel_relaxed(val, timer->func_base + (reg & 0xff));
272 }
273 
274 static inline void __omap_dm_timer_init_regs(struct omap_dm_timer *timer)
275 {
276 	u32 tidr;
277 
278 	/* Assume v1 ip if bits [31:16] are zero */
279 	tidr = readl_relaxed(timer->io_base);
280 	if (!(tidr >> 16)) {
281 		timer->revision = 1;
282 		timer->irq_stat = timer->io_base + OMAP_TIMER_V1_STAT_OFFSET;
283 		timer->irq_ena = timer->io_base + OMAP_TIMER_V1_INT_EN_OFFSET;
284 		timer->irq_dis = timer->io_base + OMAP_TIMER_V1_INT_EN_OFFSET;
285 		timer->pend = timer->io_base + _OMAP_TIMER_WRITE_PEND_OFFSET;
286 		timer->func_base = timer->io_base;
287 	} else {
288 		timer->revision = 2;
289 		timer->irq_stat = timer->io_base + OMAP_TIMER_V2_IRQSTATUS;
290 		timer->irq_ena = timer->io_base + OMAP_TIMER_V2_IRQENABLE_SET;
291 		timer->irq_dis = timer->io_base + OMAP_TIMER_V2_IRQENABLE_CLR;
292 		timer->pend = timer->io_base +
293 			_OMAP_TIMER_WRITE_PEND_OFFSET +
294 				OMAP_TIMER_V2_FUNC_OFFSET;
295 		timer->func_base = timer->io_base + OMAP_TIMER_V2_FUNC_OFFSET;
296 	}
297 }
298 
299 /*
300  * __omap_dm_timer_enable_posted - enables write posted mode
301  * @timer:      pointer to timer instance handle
302  *
303  * Enables the write posted mode for the timer. When posted mode is enabled
304  * writes to certain timer registers are immediately acknowledged by the
305  * internal bus and hence prevents stalling the CPU waiting for the write to
306  * complete. Enabling this feature can improve performance for writing to the
307  * timer registers.
308  */
309 static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer)
310 {
311 	if (timer->posted)
312 		return;
313 
314 	if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) {
315 		timer->posted = OMAP_TIMER_NONPOSTED;
316 		__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0, 0);
317 		return;
318 	}
319 
320 	__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG,
321 			      OMAP_TIMER_CTRL_POSTED, 0);
322 	timer->context.tsicr = OMAP_TIMER_CTRL_POSTED;
323 	timer->posted = OMAP_TIMER_POSTED;
324 }
325 
326 /**
327  * __omap_dm_timer_override_errata - override errata flags for a timer
328  * @timer:      pointer to timer handle
329  * @errata:	errata flags to be ignored
330  *
331  * For a given timer, override a timer errata by clearing the flags
332  * specified by the errata argument. A specific erratum should only be
333  * overridden for a timer if the timer is used in such a way the erratum
334  * has no impact.
335  */
336 static inline void __omap_dm_timer_override_errata(struct omap_dm_timer *timer,
337 						   u32 errata)
338 {
339 	timer->errata &= ~errata;
340 }
341 
342 static inline void __omap_dm_timer_stop(struct omap_dm_timer *timer,
343 					int posted, unsigned long rate)
344 {
345 	u32 l;
346 
347 	l = __omap_dm_timer_read(timer, OMAP_TIMER_CTRL_REG, posted);
348 	if (l & OMAP_TIMER_CTRL_ST) {
349 		l &= ~0x1;
350 		__omap_dm_timer_write(timer, OMAP_TIMER_CTRL_REG, l, posted);
351 #ifdef CONFIG_ARCH_OMAP2PLUS
352 		/* Readback to make sure write has completed */
353 		__omap_dm_timer_read(timer, OMAP_TIMER_CTRL_REG, posted);
354 		/*
355 		 * Wait for functional clock period x 3.5 to make sure that
356 		 * timer is stopped
357 		 */
358 		udelay(3500000 / rate + 1);
359 #endif
360 	}
361 
362 	/* Ack possibly pending interrupt */
363 	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, timer->irq_stat);
364 }
365 
366 static inline void __omap_dm_timer_load_start(struct omap_dm_timer *timer,
367 						u32 ctrl, unsigned int load,
368 						int posted)
369 {
370 	__omap_dm_timer_write(timer, OMAP_TIMER_COUNTER_REG, load, posted);
371 	__omap_dm_timer_write(timer, OMAP_TIMER_CTRL_REG, ctrl, posted);
372 }
373 
374 static inline void __omap_dm_timer_int_enable(struct omap_dm_timer *timer,
375 						unsigned int value)
376 {
377 	writel_relaxed(value, timer->irq_ena);
378 	__omap_dm_timer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, value, 0);
379 }
380 
381 static inline unsigned int
382 __omap_dm_timer_read_counter(struct omap_dm_timer *timer, int posted)
383 {
384 	return __omap_dm_timer_read(timer, OMAP_TIMER_COUNTER_REG, posted);
385 }
386 
387 static inline void __omap_dm_timer_write_status(struct omap_dm_timer *timer,
388 						unsigned int value)
389 {
390 	writel_relaxed(value, timer->irq_stat);
391 }
392 #endif /* CONFIG_ARCH_OMAP1 || CONFIG_ARCH_OMAP2PLUS */
393 #endif /* __CLOCKSOURCE_DMTIMER_H */
394