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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 	unsigned long rate;
109 	unsigned reserved:1;
110 	unsigned posted:1;
111 	struct timer_regs context;
112 	int (*get_context_loss_count)(struct device *);
113 	int ctx_loss_count;
114 	int revision;
115 	u32 capability;
116 	u32 errata;
117 	struct platform_device *pdev;
118 	struct list_head node;
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, see
252  * include/linux/platform_data/pwm_omap_dmtimer.h
253  */
254 #if defined(CONFIG_ARCH_OMAP1) || defined(CONFIG_ARCH_OMAP2PLUS)
__omap_dm_timer_read(struct omap_dm_timer * timer,u32 reg,int posted)255 static inline u32 __omap_dm_timer_read(struct omap_dm_timer *timer, u32 reg,
256 						int posted)
257 {
258 	if (posted)
259 		while (readl_relaxed(timer->pend) & (reg >> WPSHIFT))
260 			cpu_relax();
261 
262 	return readl_relaxed(timer->func_base + (reg & 0xff));
263 }
264 
__omap_dm_timer_write(struct omap_dm_timer * timer,u32 reg,u32 val,int posted)265 static inline void __omap_dm_timer_write(struct omap_dm_timer *timer,
266 					u32 reg, u32 val, int posted)
267 {
268 	if (posted)
269 		while (readl_relaxed(timer->pend) & (reg >> WPSHIFT))
270 			cpu_relax();
271 
272 	writel_relaxed(val, timer->func_base + (reg & 0xff));
273 }
274 
__omap_dm_timer_init_regs(struct omap_dm_timer * timer)275 static inline void __omap_dm_timer_init_regs(struct omap_dm_timer *timer)
276 {
277 	u32 tidr;
278 
279 	/* Assume v1 ip if bits [31:16] are zero */
280 	tidr = readl_relaxed(timer->io_base);
281 	if (!(tidr >> 16)) {
282 		timer->revision = 1;
283 		timer->irq_stat = timer->io_base + OMAP_TIMER_V1_STAT_OFFSET;
284 		timer->irq_ena = timer->io_base + OMAP_TIMER_V1_INT_EN_OFFSET;
285 		timer->irq_dis = timer->io_base + OMAP_TIMER_V1_INT_EN_OFFSET;
286 		timer->pend = timer->io_base + _OMAP_TIMER_WRITE_PEND_OFFSET;
287 		timer->func_base = timer->io_base;
288 	} else {
289 		timer->revision = 2;
290 		timer->irq_stat = timer->io_base + OMAP_TIMER_V2_IRQSTATUS;
291 		timer->irq_ena = timer->io_base + OMAP_TIMER_V2_IRQENABLE_SET;
292 		timer->irq_dis = timer->io_base + OMAP_TIMER_V2_IRQENABLE_CLR;
293 		timer->pend = timer->io_base +
294 			_OMAP_TIMER_WRITE_PEND_OFFSET +
295 				OMAP_TIMER_V2_FUNC_OFFSET;
296 		timer->func_base = timer->io_base + OMAP_TIMER_V2_FUNC_OFFSET;
297 	}
298 }
299 
300 /*
301  * __omap_dm_timer_enable_posted - enables write posted mode
302  * @timer:      pointer to timer instance handle
303  *
304  * Enables the write posted mode for the timer. When posted mode is enabled
305  * writes to certain timer registers are immediately acknowledged by the
306  * internal bus and hence prevents stalling the CPU waiting for the write to
307  * complete. Enabling this feature can improve performance for writing to the
308  * timer registers.
309  */
__omap_dm_timer_enable_posted(struct omap_dm_timer * timer)310 static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer)
311 {
312 	if (timer->posted)
313 		return;
314 
315 	if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) {
316 		timer->posted = OMAP_TIMER_NONPOSTED;
317 		__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0, 0);
318 		return;
319 	}
320 
321 	__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG,
322 			      OMAP_TIMER_CTRL_POSTED, 0);
323 	timer->context.tsicr = OMAP_TIMER_CTRL_POSTED;
324 	timer->posted = OMAP_TIMER_POSTED;
325 }
326 
327 /**
328  * __omap_dm_timer_override_errata - override errata flags for a timer
329  * @timer:      pointer to timer handle
330  * @errata:	errata flags to be ignored
331  *
332  * For a given timer, override a timer errata by clearing the flags
333  * specified by the errata argument. A specific erratum should only be
334  * overridden for a timer if the timer is used in such a way the erratum
335  * has no impact.
336  */
__omap_dm_timer_override_errata(struct omap_dm_timer * timer,u32 errata)337 static inline void __omap_dm_timer_override_errata(struct omap_dm_timer *timer,
338 						   u32 errata)
339 {
340 	timer->errata &= ~errata;
341 }
342 
__omap_dm_timer_stop(struct omap_dm_timer * timer,int posted,unsigned long rate)343 static inline void __omap_dm_timer_stop(struct omap_dm_timer *timer,
344 					int posted, unsigned long rate)
345 {
346 	u32 l;
347 
348 	l = __omap_dm_timer_read(timer, OMAP_TIMER_CTRL_REG, posted);
349 	if (l & OMAP_TIMER_CTRL_ST) {
350 		l &= ~0x1;
351 		__omap_dm_timer_write(timer, OMAP_TIMER_CTRL_REG, l, posted);
352 #ifdef CONFIG_ARCH_OMAP2PLUS
353 		/* Readback to make sure write has completed */
354 		__omap_dm_timer_read(timer, OMAP_TIMER_CTRL_REG, posted);
355 		/*
356 		 * Wait for functional clock period x 3.5 to make sure that
357 		 * timer is stopped
358 		 */
359 		udelay(3500000 / rate + 1);
360 #endif
361 	}
362 
363 	/* Ack possibly pending interrupt */
364 	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, timer->irq_stat);
365 }
366 
__omap_dm_timer_load_start(struct omap_dm_timer * timer,u32 ctrl,unsigned int load,int posted)367 static inline void __omap_dm_timer_load_start(struct omap_dm_timer *timer,
368 						u32 ctrl, unsigned int load,
369 						int posted)
370 {
371 	__omap_dm_timer_write(timer, OMAP_TIMER_COUNTER_REG, load, posted);
372 	__omap_dm_timer_write(timer, OMAP_TIMER_CTRL_REG, ctrl, posted);
373 }
374 
__omap_dm_timer_int_enable(struct omap_dm_timer * timer,unsigned int value)375 static inline void __omap_dm_timer_int_enable(struct omap_dm_timer *timer,
376 						unsigned int value)
377 {
378 	writel_relaxed(value, timer->irq_ena);
379 	__omap_dm_timer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, value, 0);
380 }
381 
382 static inline unsigned int
__omap_dm_timer_read_counter(struct omap_dm_timer * timer,int posted)383 __omap_dm_timer_read_counter(struct omap_dm_timer *timer, int posted)
384 {
385 	return __omap_dm_timer_read(timer, OMAP_TIMER_COUNTER_REG, posted);
386 }
387 
__omap_dm_timer_write_status(struct omap_dm_timer * timer,unsigned int value)388 static inline void __omap_dm_timer_write_status(struct omap_dm_timer *timer,
389 						unsigned int value)
390 {
391 	writel_relaxed(value, timer->irq_stat);
392 }
393 #endif /* CONFIG_ARCH_OMAP1 || CONFIG_ARCH_OMAP2PLUS */
394 #endif /* __CLOCKSOURCE_DMTIMER_H */
395