xref: /openbmc/linux/arch/arm/mach-omap1/pm.c (revision cabce92d)
1 /*
2  * linux/arch/arm/mach-omap1/pm.c
3  *
4  * OMAP Power Management Routines
5  *
6  * Original code for the SA11x0:
7  * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
8  *
9  * Modified for the PXA250 by Nicolas Pitre:
10  * Copyright (c) 2002 Monta Vista Software, Inc.
11  *
12  * Modified for the OMAP1510 by David Singleton:
13  * Copyright (c) 2002 Monta Vista Software, Inc.
14  *
15  * Cleanup 2004 for OMAP1510/1610 by Dirk Behme <dirk.behme@de.bosch.com>
16  *
17  * This program is free software; you can redistribute it and/or modify it
18  * under the terms of the GNU General Public License as published by the
19  * Free Software Foundation; either version 2 of the License, or (at your
20  * option) any later version.
21  *
22  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
25  * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
29  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  * You should have received a copy of the GNU General Public License along
34  * with this program; if not, write to the Free Software Foundation, Inc.,
35  * 675 Mass Ave, Cambridge, MA 02139, USA.
36  */
37 
38 #include <linux/suspend.h>
39 #include <linux/sched.h>
40 #include <linux/debugfs.h>
41 #include <linux/seq_file.h>
42 #include <linux/interrupt.h>
43 #include <linux/sysfs.h>
44 #include <linux/module.h>
45 #include <linux/io.h>
46 #include <linux/atomic.h>
47 #include <linux/cpu.h>
48 
49 #include <asm/fncpy.h>
50 #include <asm/system_misc.h>
51 #include <asm/irq.h>
52 #include <asm/mach/time.h>
53 #include <asm/mach/irq.h>
54 
55 #include <linux/soc/ti/omap1-io.h>
56 #include "tc.h"
57 #include <linux/omap-dma.h>
58 #include <clocksource/timer-ti-dm.h>
59 
60 #include "hardware.h"
61 #include "mux.h"
62 #include "irqs.h"
63 #include "iomap.h"
64 #include "clock.h"
65 #include "pm.h"
66 #include "soc.h"
67 #include "sram.h"
68 
69 static unsigned int arm_sleep_save[ARM_SLEEP_SAVE_SIZE];
70 static unsigned short dsp_sleep_save[DSP_SLEEP_SAVE_SIZE];
71 static unsigned short ulpd_sleep_save[ULPD_SLEEP_SAVE_SIZE];
72 static unsigned int mpui1510_sleep_save[MPUI1510_SLEEP_SAVE_SIZE];
73 static unsigned int mpui1610_sleep_save[MPUI1610_SLEEP_SAVE_SIZE];
74 
75 static unsigned short enable_dyn_sleep;
76 
77 static ssize_t idle_show(struct kobject *kobj, struct kobj_attribute *attr,
78 			 char *buf)
79 {
80 	return sprintf(buf, "%hu\n", enable_dyn_sleep);
81 }
82 
83 static ssize_t idle_store(struct kobject *kobj, struct kobj_attribute *attr,
84 			  const char * buf, size_t n)
85 {
86 	unsigned short value;
87 	if (sscanf(buf, "%hu", &value) != 1 ||
88 	    (value != 0 && value != 1) ||
89 	    (value != 0 && !IS_ENABLED(CONFIG_OMAP_32K_TIMER))) {
90 		pr_err("idle_sleep_store: Invalid value\n");
91 		return -EINVAL;
92 	}
93 	enable_dyn_sleep = value;
94 	return n;
95 }
96 
97 static struct kobj_attribute sleep_while_idle_attr =
98 	__ATTR(sleep_while_idle, 0644, idle_show, idle_store);
99 
100 
101 static void (*omap_sram_suspend)(unsigned long r0, unsigned long r1) = NULL;
102 
103 /*
104  * Let's power down on idle, but only if we are really
105  * idle, because once we start down the path of
106  * going idle we continue to do idle even if we get
107  * a clock tick interrupt . .
108  */
109 void omap1_pm_idle(void)
110 {
111 	extern __u32 arm_idlect1_mask;
112 	__u32 use_idlect1 = arm_idlect1_mask;
113 
114 	local_fiq_disable();
115 
116 #if defined(CONFIG_OMAP_MPU_TIMER) && !defined(CONFIG_OMAP_DM_TIMER)
117 	use_idlect1 = use_idlect1 & ~(1 << 9);
118 #endif
119 
120 #ifdef CONFIG_OMAP_DM_TIMER
121 	use_idlect1 = omap_dm_timer_modify_idlect_mask(use_idlect1);
122 #endif
123 
124 	if (omap_dma_running())
125 		use_idlect1 &= ~(1 << 6);
126 
127 	/*
128 	 * We should be able to remove the do_sleep variable and multiple
129 	 * tests above as soon as drivers, timer and DMA code have been fixed.
130 	 * Even the sleep block count should become obsolete.
131 	 */
132 	if ((use_idlect1 != ~0) || !enable_dyn_sleep) {
133 
134 		__u32 saved_idlect1 = omap_readl(ARM_IDLECT1);
135 		if (cpu_is_omap15xx())
136 			use_idlect1 &= OMAP1510_BIG_SLEEP_REQUEST;
137 		else
138 			use_idlect1 &= OMAP1610_IDLECT1_SLEEP_VAL;
139 		omap_writel(use_idlect1, ARM_IDLECT1);
140 		__asm__ volatile ("mcr	p15, 0, r0, c7, c0, 4");
141 		omap_writel(saved_idlect1, ARM_IDLECT1);
142 
143 		local_fiq_enable();
144 		return;
145 	}
146 	omap_sram_suspend(omap_readl(ARM_IDLECT1),
147 			  omap_readl(ARM_IDLECT2));
148 
149 	local_fiq_enable();
150 }
151 
152 /*
153  * Configuration of the wakeup event is board specific. For the
154  * moment we put it into this helper function. Later it may move
155  * to board specific files.
156  */
157 static void omap_pm_wakeup_setup(void)
158 {
159 	u32 level1_wake = 0;
160 	u32 level2_wake = OMAP_IRQ_BIT(INT_UART2);
161 
162 	/*
163 	 * Turn off all interrupts except GPIO bank 1, L1-2nd level cascade,
164 	 * and the L2 wakeup interrupts: keypad and UART2. Note that the
165 	 * drivers must still separately call omap_set_gpio_wakeup() to
166 	 * wake up to a GPIO interrupt.
167 	 */
168 	if (cpu_is_omap15xx())
169 		level1_wake = OMAP_IRQ_BIT(INT_GPIO_BANK1) |
170 			OMAP_IRQ_BIT(INT_1510_IH2_IRQ);
171 	else if (cpu_is_omap16xx())
172 		level1_wake = OMAP_IRQ_BIT(INT_GPIO_BANK1) |
173 			OMAP_IRQ_BIT(INT_1610_IH2_IRQ);
174 
175 	omap_writel(~level1_wake, OMAP_IH1_MIR);
176 
177 	if (cpu_is_omap15xx()) {
178 		level2_wake |= OMAP_IRQ_BIT(INT_KEYBOARD);
179 		omap_writel(~level2_wake,  OMAP_IH2_MIR);
180 	} else if (cpu_is_omap16xx()) {
181 		level2_wake |= OMAP_IRQ_BIT(INT_KEYBOARD);
182 		omap_writel(~level2_wake, OMAP_IH2_0_MIR);
183 
184 		/* INT_1610_WAKE_UP_REQ is needed for GPIO wakeup... */
185 		omap_writel(~OMAP_IRQ_BIT(INT_1610_WAKE_UP_REQ),
186 			    OMAP_IH2_1_MIR);
187 		omap_writel(~0x0, OMAP_IH2_2_MIR);
188 		omap_writel(~0x0, OMAP_IH2_3_MIR);
189 	}
190 
191 	/*  New IRQ agreement, recalculate in cascade order */
192 	omap_writel(1, OMAP_IH2_CONTROL);
193 	omap_writel(1, OMAP_IH1_CONTROL);
194 }
195 
196 #define EN_DSPCK	13	/* ARM_CKCTL */
197 #define EN_APICK	6	/* ARM_IDLECT2 */
198 #define DSP_EN		1	/* ARM_RSTCT1 */
199 
200 void omap1_pm_suspend(void)
201 {
202 	unsigned long arg0 = 0, arg1 = 0;
203 
204 	printk(KERN_INFO "PM: OMAP%x is trying to enter deep sleep...\n",
205 		omap_rev());
206 
207 	omap_serial_wake_trigger(1);
208 
209 	if (!cpu_is_omap15xx())
210 		omap_writew(0xffff, ULPD_SOFT_DISABLE_REQ_REG);
211 
212 	/*
213 	 * Step 1: turn off interrupts (FIXME: NOTE: already disabled)
214 	 */
215 
216 	local_irq_disable();
217 	local_fiq_disable();
218 
219 	/*
220 	 * Step 2: save registers
221 	 *
222 	 * The omap is a strange/beautiful device. The caches, memory
223 	 * and register state are preserved across power saves.
224 	 * We have to save and restore very little register state to
225 	 * idle the omap.
226          *
227 	 * Save interrupt, MPUI, ARM and UPLD control registers.
228 	 */
229 
230 	if (cpu_is_omap15xx()) {
231 		MPUI1510_SAVE(OMAP_IH1_MIR);
232 		MPUI1510_SAVE(OMAP_IH2_MIR);
233 		MPUI1510_SAVE(MPUI_CTRL);
234 		MPUI1510_SAVE(MPUI_DSP_BOOT_CONFIG);
235 		MPUI1510_SAVE(MPUI_DSP_API_CONFIG);
236 		MPUI1510_SAVE(EMIFS_CONFIG);
237 		MPUI1510_SAVE(EMIFF_SDRAM_CONFIG);
238 	} else if (cpu_is_omap16xx()) {
239 		MPUI1610_SAVE(OMAP_IH1_MIR);
240 		MPUI1610_SAVE(OMAP_IH2_0_MIR);
241 		MPUI1610_SAVE(OMAP_IH2_1_MIR);
242 		MPUI1610_SAVE(OMAP_IH2_2_MIR);
243 		MPUI1610_SAVE(OMAP_IH2_3_MIR);
244 		MPUI1610_SAVE(MPUI_CTRL);
245 		MPUI1610_SAVE(MPUI_DSP_BOOT_CONFIG);
246 		MPUI1610_SAVE(MPUI_DSP_API_CONFIG);
247 		MPUI1610_SAVE(EMIFS_CONFIG);
248 		MPUI1610_SAVE(EMIFF_SDRAM_CONFIG);
249 	}
250 
251 	ARM_SAVE(ARM_CKCTL);
252 	ARM_SAVE(ARM_IDLECT1);
253 	ARM_SAVE(ARM_IDLECT2);
254 	if (!(cpu_is_omap15xx()))
255 		ARM_SAVE(ARM_IDLECT3);
256 	ARM_SAVE(ARM_EWUPCT);
257 	ARM_SAVE(ARM_RSTCT1);
258 	ARM_SAVE(ARM_RSTCT2);
259 	ARM_SAVE(ARM_SYSST);
260 	ULPD_SAVE(ULPD_CLOCK_CTRL);
261 	ULPD_SAVE(ULPD_STATUS_REQ);
262 
263 	/* (Step 3 removed - we now allow deep sleep by default) */
264 
265 	/*
266 	 * Step 4: OMAP DSP Shutdown
267 	 */
268 
269 	/* stop DSP */
270 	omap_writew(omap_readw(ARM_RSTCT1) & ~(1 << DSP_EN), ARM_RSTCT1);
271 
272 	/* shut down dsp_ck */
273 	omap_writew(omap_readw(ARM_CKCTL) & ~(1 << EN_DSPCK), ARM_CKCTL);
274 
275 	/* temporarily enabling api_ck to access DSP registers */
276 	omap_writew(omap_readw(ARM_IDLECT2) | 1 << EN_APICK, ARM_IDLECT2);
277 
278 	/* save DSP registers */
279 	DSP_SAVE(DSP_IDLECT2);
280 
281 	/* Stop all DSP domain clocks */
282 	__raw_writew(0, DSP_IDLECT2);
283 
284 	/*
285 	 * Step 5: Wakeup Event Setup
286 	 */
287 
288 	omap_pm_wakeup_setup();
289 
290 	/*
291 	 * Step 6: ARM and Traffic controller shutdown
292 	 */
293 
294 	/* disable ARM watchdog */
295 	omap_writel(0x00F5, OMAP_WDT_TIMER_MODE);
296 	omap_writel(0x00A0, OMAP_WDT_TIMER_MODE);
297 
298 	/*
299 	 * Step 6b: ARM and Traffic controller shutdown
300 	 *
301 	 * Step 6 continues here. Prepare jump to power management
302 	 * assembly code in internal SRAM.
303 	 *
304 	 * Since the omap_cpu_suspend routine has been copied to
305 	 * SRAM, we'll do an indirect procedure call to it and pass the
306 	 * contents of arm_idlect1 and arm_idlect2 so it can restore
307 	 * them when it wakes up and it will return.
308 	 */
309 
310 	arg0 = arm_sleep_save[ARM_SLEEP_SAVE_ARM_IDLECT1];
311 	arg1 = arm_sleep_save[ARM_SLEEP_SAVE_ARM_IDLECT2];
312 
313 	/*
314 	 * Step 6c: ARM and Traffic controller shutdown
315 	 *
316 	 * Jump to assembly code. The processor will stay there
317 	 * until wake up.
318 	 */
319 	omap_sram_suspend(arg0, arg1);
320 
321 	/*
322 	 * If we are here, processor is woken up!
323 	 */
324 
325 	/*
326 	 * Restore DSP clocks
327 	 */
328 
329 	/* again temporarily enabling api_ck to access DSP registers */
330 	omap_writew(omap_readw(ARM_IDLECT2) | 1 << EN_APICK, ARM_IDLECT2);
331 
332 	/* Restore DSP domain clocks */
333 	DSP_RESTORE(DSP_IDLECT2);
334 
335 	/*
336 	 * Restore ARM state, except ARM_IDLECT1/2 which omap_cpu_suspend did
337 	 */
338 
339 	if (!(cpu_is_omap15xx()))
340 		ARM_RESTORE(ARM_IDLECT3);
341 	ARM_RESTORE(ARM_CKCTL);
342 	ARM_RESTORE(ARM_EWUPCT);
343 	ARM_RESTORE(ARM_RSTCT1);
344 	ARM_RESTORE(ARM_RSTCT2);
345 	ARM_RESTORE(ARM_SYSST);
346 	ULPD_RESTORE(ULPD_CLOCK_CTRL);
347 	ULPD_RESTORE(ULPD_STATUS_REQ);
348 
349 	if (cpu_is_omap15xx()) {
350 		MPUI1510_RESTORE(MPUI_CTRL);
351 		MPUI1510_RESTORE(MPUI_DSP_BOOT_CONFIG);
352 		MPUI1510_RESTORE(MPUI_DSP_API_CONFIG);
353 		MPUI1510_RESTORE(EMIFS_CONFIG);
354 		MPUI1510_RESTORE(EMIFF_SDRAM_CONFIG);
355 		MPUI1510_RESTORE(OMAP_IH1_MIR);
356 		MPUI1510_RESTORE(OMAP_IH2_MIR);
357 	} else if (cpu_is_omap16xx()) {
358 		MPUI1610_RESTORE(MPUI_CTRL);
359 		MPUI1610_RESTORE(MPUI_DSP_BOOT_CONFIG);
360 		MPUI1610_RESTORE(MPUI_DSP_API_CONFIG);
361 		MPUI1610_RESTORE(EMIFS_CONFIG);
362 		MPUI1610_RESTORE(EMIFF_SDRAM_CONFIG);
363 
364 		MPUI1610_RESTORE(OMAP_IH1_MIR);
365 		MPUI1610_RESTORE(OMAP_IH2_0_MIR);
366 		MPUI1610_RESTORE(OMAP_IH2_1_MIR);
367 		MPUI1610_RESTORE(OMAP_IH2_2_MIR);
368 		MPUI1610_RESTORE(OMAP_IH2_3_MIR);
369 	}
370 
371 	if (!cpu_is_omap15xx())
372 		omap_writew(0, ULPD_SOFT_DISABLE_REQ_REG);
373 
374 	/*
375 	 * Re-enable interrupts
376 	 */
377 
378 	local_irq_enable();
379 	local_fiq_enable();
380 
381 	omap_serial_wake_trigger(0);
382 
383 	printk(KERN_INFO "PM: OMAP%x is re-starting from deep sleep...\n",
384 		omap_rev());
385 }
386 
387 #ifdef CONFIG_DEBUG_FS
388 /*
389  * Read system PM registers for debugging
390  */
391 static int omap_pm_debug_show(struct seq_file *m, void *v)
392 {
393 	ARM_SAVE(ARM_CKCTL);
394 	ARM_SAVE(ARM_IDLECT1);
395 	ARM_SAVE(ARM_IDLECT2);
396 	if (!(cpu_is_omap15xx()))
397 		ARM_SAVE(ARM_IDLECT3);
398 	ARM_SAVE(ARM_EWUPCT);
399 	ARM_SAVE(ARM_RSTCT1);
400 	ARM_SAVE(ARM_RSTCT2);
401 	ARM_SAVE(ARM_SYSST);
402 
403 	ULPD_SAVE(ULPD_IT_STATUS);
404 	ULPD_SAVE(ULPD_CLOCK_CTRL);
405 	ULPD_SAVE(ULPD_SOFT_REQ);
406 	ULPD_SAVE(ULPD_STATUS_REQ);
407 	ULPD_SAVE(ULPD_DPLL_CTRL);
408 	ULPD_SAVE(ULPD_POWER_CTRL);
409 
410 	if (cpu_is_omap15xx()) {
411 		MPUI1510_SAVE(MPUI_CTRL);
412 		MPUI1510_SAVE(MPUI_DSP_STATUS);
413 		MPUI1510_SAVE(MPUI_DSP_BOOT_CONFIG);
414 		MPUI1510_SAVE(MPUI_DSP_API_CONFIG);
415 		MPUI1510_SAVE(EMIFF_SDRAM_CONFIG);
416 		MPUI1510_SAVE(EMIFS_CONFIG);
417 	} else if (cpu_is_omap16xx()) {
418 		MPUI1610_SAVE(MPUI_CTRL);
419 		MPUI1610_SAVE(MPUI_DSP_STATUS);
420 		MPUI1610_SAVE(MPUI_DSP_BOOT_CONFIG);
421 		MPUI1610_SAVE(MPUI_DSP_API_CONFIG);
422 		MPUI1610_SAVE(EMIFF_SDRAM_CONFIG);
423 		MPUI1610_SAVE(EMIFS_CONFIG);
424 	}
425 
426 	seq_printf(m,
427 		   "ARM_CKCTL_REG:            0x%-8x     \n"
428 		   "ARM_IDLECT1_REG:          0x%-8x     \n"
429 		   "ARM_IDLECT2_REG:          0x%-8x     \n"
430 		   "ARM_IDLECT3_REG:	      0x%-8x     \n"
431 		   "ARM_EWUPCT_REG:           0x%-8x     \n"
432 		   "ARM_RSTCT1_REG:           0x%-8x     \n"
433 		   "ARM_RSTCT2_REG:           0x%-8x     \n"
434 		   "ARM_SYSST_REG:            0x%-8x     \n"
435 		   "ULPD_IT_STATUS_REG:       0x%-4x     \n"
436 		   "ULPD_CLOCK_CTRL_REG:      0x%-4x     \n"
437 		   "ULPD_SOFT_REQ_REG:        0x%-4x     \n"
438 		   "ULPD_DPLL_CTRL_REG:       0x%-4x     \n"
439 		   "ULPD_STATUS_REQ_REG:      0x%-4x     \n"
440 		   "ULPD_POWER_CTRL_REG:      0x%-4x     \n",
441 		   ARM_SHOW(ARM_CKCTL),
442 		   ARM_SHOW(ARM_IDLECT1),
443 		   ARM_SHOW(ARM_IDLECT2),
444 		   ARM_SHOW(ARM_IDLECT3),
445 		   ARM_SHOW(ARM_EWUPCT),
446 		   ARM_SHOW(ARM_RSTCT1),
447 		   ARM_SHOW(ARM_RSTCT2),
448 		   ARM_SHOW(ARM_SYSST),
449 		   ULPD_SHOW(ULPD_IT_STATUS),
450 		   ULPD_SHOW(ULPD_CLOCK_CTRL),
451 		   ULPD_SHOW(ULPD_SOFT_REQ),
452 		   ULPD_SHOW(ULPD_DPLL_CTRL),
453 		   ULPD_SHOW(ULPD_STATUS_REQ),
454 		   ULPD_SHOW(ULPD_POWER_CTRL));
455 
456 	if (cpu_is_omap15xx()) {
457 		seq_printf(m,
458 			   "MPUI1510_CTRL_REG             0x%-8x \n"
459 			   "MPUI1510_DSP_STATUS_REG:      0x%-8x \n"
460 			   "MPUI1510_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
461 			   "MPUI1510_DSP_API_CONFIG_REG:  0x%-8x \n"
462 			   "MPUI1510_SDRAM_CONFIG_REG:    0x%-8x \n"
463 			   "MPUI1510_EMIFS_CONFIG_REG:    0x%-8x \n",
464 			   MPUI1510_SHOW(MPUI_CTRL),
465 			   MPUI1510_SHOW(MPUI_DSP_STATUS),
466 			   MPUI1510_SHOW(MPUI_DSP_BOOT_CONFIG),
467 			   MPUI1510_SHOW(MPUI_DSP_API_CONFIG),
468 			   MPUI1510_SHOW(EMIFF_SDRAM_CONFIG),
469 			   MPUI1510_SHOW(EMIFS_CONFIG));
470 	} else if (cpu_is_omap16xx()) {
471 		seq_printf(m,
472 			   "MPUI1610_CTRL_REG             0x%-8x \n"
473 			   "MPUI1610_DSP_STATUS_REG:      0x%-8x \n"
474 			   "MPUI1610_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
475 			   "MPUI1610_DSP_API_CONFIG_REG:  0x%-8x \n"
476 			   "MPUI1610_SDRAM_CONFIG_REG:    0x%-8x \n"
477 			   "MPUI1610_EMIFS_CONFIG_REG:    0x%-8x \n",
478 			   MPUI1610_SHOW(MPUI_CTRL),
479 			   MPUI1610_SHOW(MPUI_DSP_STATUS),
480 			   MPUI1610_SHOW(MPUI_DSP_BOOT_CONFIG),
481 			   MPUI1610_SHOW(MPUI_DSP_API_CONFIG),
482 			   MPUI1610_SHOW(EMIFF_SDRAM_CONFIG),
483 			   MPUI1610_SHOW(EMIFS_CONFIG));
484 	}
485 
486 	return 0;
487 }
488 
489 DEFINE_SHOW_ATTRIBUTE(omap_pm_debug);
490 
491 static void omap_pm_init_debugfs(void)
492 {
493 	struct dentry *d;
494 
495 	d = debugfs_create_dir("pm_debug", NULL);
496 	debugfs_create_file("omap_pm", S_IWUSR | S_IRUGO, d, NULL,
497 			    &omap_pm_debug_fops);
498 }
499 
500 #endif /* CONFIG_DEBUG_FS */
501 
502 /*
503  *	omap_pm_prepare - Do preliminary suspend work.
504  *
505  */
506 static int omap_pm_prepare(void)
507 {
508 	/* We cannot sleep in idle until we have resumed */
509 	cpu_idle_poll_ctrl(true);
510 	return 0;
511 }
512 
513 
514 /*
515  *	omap_pm_enter - Actually enter a sleep state.
516  *	@state:		State we're entering.
517  *
518  */
519 
520 static int omap_pm_enter(suspend_state_t state)
521 {
522 	switch (state)
523 	{
524 	case PM_SUSPEND_MEM:
525 		omap1_pm_suspend();
526 		break;
527 	default:
528 		return -EINVAL;
529 	}
530 
531 	return 0;
532 }
533 
534 
535 /**
536  *	omap_pm_finish - Finish up suspend sequence.
537  *
538  *	This is called after we wake back up (or if entering the sleep state
539  *	failed).
540  */
541 
542 static void omap_pm_finish(void)
543 {
544 	cpu_idle_poll_ctrl(false);
545 }
546 
547 
548 static irqreturn_t omap_wakeup_interrupt(int irq, void *dev)
549 {
550 	return IRQ_HANDLED;
551 }
552 
553 
554 
555 static const struct platform_suspend_ops omap_pm_ops = {
556 	.prepare	= omap_pm_prepare,
557 	.enter		= omap_pm_enter,
558 	.finish		= omap_pm_finish,
559 	.valid		= suspend_valid_only_mem,
560 };
561 
562 static int __init omap_pm_init(void)
563 {
564 	int error = 0;
565 	int irq;
566 
567 	if (!cpu_class_is_omap1())
568 		return -ENODEV;
569 
570 	pr_info("Power Management for TI OMAP.\n");
571 
572 	if (!IS_ENABLED(CONFIG_OMAP_32K_TIMER))
573 		pr_info("OMAP1 PM: sleep states in idle disabled due to no 32KiHz timer\n");
574 
575 	if (!IS_ENABLED(CONFIG_OMAP_DM_TIMER))
576 		pr_info("OMAP1 PM: sleep states in idle disabled due to no DMTIMER support\n");
577 
578 	if (IS_ENABLED(CONFIG_OMAP_32K_TIMER) &&
579 	    IS_ENABLED(CONFIG_OMAP_DM_TIMER)) {
580 		/* OMAP16xx only */
581 		pr_info("OMAP1 PM: sleep states in idle enabled\n");
582 		enable_dyn_sleep = 1;
583 	}
584 
585 	/*
586 	 * We copy the assembler sleep/wakeup routines to SRAM.
587 	 * These routines need to be in SRAM as that's the only
588 	 * memory the MPU can see when it wakes up.
589 	 */
590 	if (cpu_is_omap15xx()) {
591 		omap_sram_suspend = omap_sram_push(omap1510_cpu_suspend,
592 						   omap1510_cpu_suspend_sz);
593 	} else if (cpu_is_omap16xx()) {
594 		omap_sram_suspend = omap_sram_push(omap1610_cpu_suspend,
595 						   omap1610_cpu_suspend_sz);
596 	}
597 
598 	if (omap_sram_suspend == NULL) {
599 		printk(KERN_ERR "PM not initialized: Missing SRAM support\n");
600 		return -ENODEV;
601 	}
602 
603 	arm_pm_idle = omap1_pm_idle;
604 
605 	if (cpu_is_omap16xx())
606 		irq = INT_1610_WAKE_UP_REQ;
607 	else
608 		irq = -1;
609 
610 	if (irq >= 0) {
611 		if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup", NULL))
612 			pr_err("Failed to request irq %d (peripheral wakeup)\n", irq);
613 	}
614 
615 	/* Program new power ramp-up time
616 	 * (0 for most boards since we don't lower voltage when in deep sleep)
617 	 */
618 	omap_writew(ULPD_SETUP_ANALOG_CELL_3_VAL, ULPD_SETUP_ANALOG_CELL_3);
619 
620 	/* Setup ULPD POWER_CTRL_REG - enter deep sleep whenever possible */
621 	omap_writew(ULPD_POWER_CTRL_REG_VAL, ULPD_POWER_CTRL);
622 
623 	/* Configure IDLECT3 */
624 	if (cpu_is_omap16xx())
625 		omap_writel(OMAP1610_IDLECT3_VAL, OMAP1610_IDLECT3);
626 
627 	suspend_set_ops(&omap_pm_ops);
628 
629 #ifdef CONFIG_DEBUG_FS
630 	omap_pm_init_debugfs();
631 #endif
632 
633 	error = sysfs_create_file(power_kobj, &sleep_while_idle_attr.attr);
634 	if (error)
635 		pr_err("sysfs_create_file failed: %d\n", error);
636 
637 	if (cpu_is_omap16xx()) {
638 		/* configure LOW_PWR pin */
639 		omap_cfg_reg(T20_1610_LOW_PWR);
640 	}
641 
642 	return error;
643 }
644 __initcall(omap_pm_init);
645