1 /*
2  * OMAP2 Power Management Routines
3  *
4  * Copyright (C) 2005 Texas Instruments, Inc.
5  * Copyright (C) 2006-2008 Nokia Corporation
6  *
7  * Written by:
8  * Richard Woodruff <r-woodruff2@ti.com>
9  * Tony Lindgren
10  * Juha Yrjola
11  * Amit Kucheria <amit.kucheria@nokia.com>
12  * Igor Stoppa <igor.stoppa@nokia.com>
13  *
14  * Based on pm.c for omap1
15  *
16  * This program is free software; you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License version 2 as
18  * published by the Free Software Foundation.
19  */
20 
21 #include <linux/suspend.h>
22 #include <linux/sched.h>
23 #include <linux/proc_fs.h>
24 #include <linux/interrupt.h>
25 #include <linux/sysfs.h>
26 #include <linux/module.h>
27 #include <linux/delay.h>
28 #include <linux/clk.h>
29 #include <linux/io.h>
30 #include <linux/irq.h>
31 #include <linux/time.h>
32 #include <linux/gpio.h>
33 
34 #include <asm/mach/time.h>
35 #include <asm/mach/irq.h>
36 #include <asm/mach-types.h>
37 
38 #include <mach/irqs.h>
39 #include <plat/clock.h>
40 #include <plat/sram.h>
41 #include <plat/dma.h>
42 #include <plat/board.h>
43 
44 #include "common.h"
45 #include "prm2xxx_3xxx.h"
46 #include "prm-regbits-24xx.h"
47 #include "cm2xxx_3xxx.h"
48 #include "cm-regbits-24xx.h"
49 #include "sdrc.h"
50 #include "pm.h"
51 #include "control.h"
52 
53 #include "powerdomain.h"
54 #include "clockdomain.h"
55 
56 #ifdef CONFIG_SUSPEND
57 static suspend_state_t suspend_state = PM_SUSPEND_ON;
is_suspending(void)58 static inline bool is_suspending(void)
59 {
60 	return (suspend_state != PM_SUSPEND_ON);
61 }
62 #else
is_suspending(void)63 static inline bool is_suspending(void)
64 {
65 	return false;
66 }
67 #endif
68 
69 static void (*omap2_sram_idle)(void);
70 static void (*omap2_sram_suspend)(u32 dllctrl, void __iomem *sdrc_dlla_ctrl,
71 				  void __iomem *sdrc_power);
72 
73 static struct powerdomain *mpu_pwrdm, *core_pwrdm;
74 static struct clockdomain *dsp_clkdm, *mpu_clkdm, *wkup_clkdm, *gfx_clkdm;
75 
76 static struct clk *osc_ck, *emul_ck;
77 
omap2_fclks_active(void)78 static int omap2_fclks_active(void)
79 {
80 	u32 f1, f2;
81 
82 	f1 = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
83 	f2 = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
84 
85 	return (f1 | f2) ? 1 : 0;
86 }
87 
omap2_enter_full_retention(void)88 static void omap2_enter_full_retention(void)
89 {
90 	u32 l;
91 
92 	/* There is 1 reference hold for all children of the oscillator
93 	 * clock, the following will remove it. If no one else uses the
94 	 * oscillator itself it will be disabled if/when we enter retention
95 	 * mode.
96 	 */
97 	clk_disable(osc_ck);
98 
99 	/* Clear old wake-up events */
100 	/* REVISIT: These write to reserved bits? */
101 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
102 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
103 	omap2_prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);
104 
105 	/*
106 	 * Set MPU powerdomain's next power state to RETENTION;
107 	 * preserve logic state during retention
108 	 */
109 	pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
110 	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);
111 
112 	/* Workaround to kill USB */
113 	l = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0) | OMAP24XX_USBSTANDBYCTRL;
114 	omap_ctrl_writel(l, OMAP2_CONTROL_DEVCONF0);
115 
116 	omap2_gpio_prepare_for_idle(0);
117 
118 	/* One last check for pending IRQs to avoid extra latency due
119 	 * to sleeping unnecessarily. */
120 	if (omap_irq_pending())
121 		goto no_sleep;
122 
123 	/* Jump to SRAM suspend code */
124 	omap2_sram_suspend(sdrc_read_reg(SDRC_DLLA_CTRL),
125 			   OMAP_SDRC_REGADDR(SDRC_DLLA_CTRL),
126 			   OMAP_SDRC_REGADDR(SDRC_POWER));
127 
128 no_sleep:
129 	omap2_gpio_resume_after_idle();
130 
131 	clk_enable(osc_ck);
132 
133 	/* clear CORE wake-up events */
134 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
135 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
136 
137 	/* wakeup domain events - bit 1: GPT1, bit5 GPIO */
138 	omap2_prm_clear_mod_reg_bits(0x4 | 0x1, WKUP_MOD, PM_WKST);
139 
140 	/* MPU domain wake events */
141 	l = omap2_prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
142 	if (l & 0x01)
143 		omap2_prm_write_mod_reg(0x01, OCP_MOD,
144 				  OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
145 	if (l & 0x20)
146 		omap2_prm_write_mod_reg(0x20, OCP_MOD,
147 				  OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
148 
149 	/* Mask future PRCM-to-MPU interrupts */
150 	omap2_prm_write_mod_reg(0x0, OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
151 }
152 
omap2_i2c_active(void)153 static int omap2_i2c_active(void)
154 {
155 	u32 l;
156 
157 	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
158 	return l & (OMAP2420_EN_I2C2_MASK | OMAP2420_EN_I2C1_MASK);
159 }
160 
161 static int sti_console_enabled;
162 
omap2_allow_mpu_retention(void)163 static int omap2_allow_mpu_retention(void)
164 {
165 	u32 l;
166 
167 	/* Check for MMC, UART2, UART1, McSPI2, McSPI1 and DSS1. */
168 	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
169 	if (l & (OMAP2420_EN_MMC_MASK | OMAP24XX_EN_UART2_MASK |
170 		 OMAP24XX_EN_UART1_MASK | OMAP24XX_EN_MCSPI2_MASK |
171 		 OMAP24XX_EN_MCSPI1_MASK | OMAP24XX_EN_DSS1_MASK))
172 		return 0;
173 	/* Check for UART3. */
174 	l = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
175 	if (l & OMAP24XX_EN_UART3_MASK)
176 		return 0;
177 	if (sti_console_enabled)
178 		return 0;
179 
180 	return 1;
181 }
182 
omap2_enter_mpu_retention(void)183 static void omap2_enter_mpu_retention(void)
184 {
185 	int only_idle = 0;
186 
187 	/* Putting MPU into the WFI state while a transfer is active
188 	 * seems to cause the I2C block to timeout. Why? Good question. */
189 	if (omap2_i2c_active())
190 		return;
191 
192 	/* The peripherals seem not to be able to wake up the MPU when
193 	 * it is in retention mode. */
194 	if (omap2_allow_mpu_retention()) {
195 		/* REVISIT: These write to reserved bits? */
196 		omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
197 		omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
198 		omap2_prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);
199 
200 		/* Try to enter MPU retention */
201 		omap2_prm_write_mod_reg((0x01 << OMAP_POWERSTATE_SHIFT) |
202 				  OMAP_LOGICRETSTATE_MASK,
203 				  MPU_MOD, OMAP2_PM_PWSTCTRL);
204 	} else {
205 		/* Block MPU retention */
206 
207 		omap2_prm_write_mod_reg(OMAP_LOGICRETSTATE_MASK, MPU_MOD,
208 						 OMAP2_PM_PWSTCTRL);
209 		only_idle = 1;
210 	}
211 
212 	omap2_sram_idle();
213 }
214 
omap2_can_sleep(void)215 static int omap2_can_sleep(void)
216 {
217 	if (omap2_fclks_active())
218 		return 0;
219 	if (osc_ck->usecount > 1)
220 		return 0;
221 	if (omap_dma_running())
222 		return 0;
223 
224 	return 1;
225 }
226 
omap2_pm_idle(void)227 static void omap2_pm_idle(void)
228 {
229 	local_irq_disable();
230 	local_fiq_disable();
231 
232 	if (!omap2_can_sleep()) {
233 		if (omap_irq_pending())
234 			goto out;
235 		omap2_enter_mpu_retention();
236 		goto out;
237 	}
238 
239 	if (omap_irq_pending())
240 		goto out;
241 
242 	omap2_enter_full_retention();
243 
244 out:
245 	local_fiq_enable();
246 	local_irq_enable();
247 }
248 
249 #ifdef CONFIG_SUSPEND
omap2_pm_begin(suspend_state_t state)250 static int omap2_pm_begin(suspend_state_t state)
251 {
252 	disable_hlt();
253 	suspend_state = state;
254 	return 0;
255 }
256 
omap2_pm_suspend(void)257 static int omap2_pm_suspend(void)
258 {
259 	u32 wken_wkup, mir1;
260 
261 	wken_wkup = omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
262 	wken_wkup &= ~OMAP24XX_EN_GPT1_MASK;
263 	omap2_prm_write_mod_reg(wken_wkup, WKUP_MOD, PM_WKEN);
264 
265 	/* Mask GPT1 */
266 	mir1 = omap_readl(0x480fe0a4);
267 	omap_writel(1 << 5, 0x480fe0ac);
268 
269 	omap2_enter_full_retention();
270 
271 	omap_writel(mir1, 0x480fe0a4);
272 	omap2_prm_write_mod_reg(wken_wkup, WKUP_MOD, PM_WKEN);
273 
274 	return 0;
275 }
276 
omap2_pm_enter(suspend_state_t state)277 static int omap2_pm_enter(suspend_state_t state)
278 {
279 	int ret = 0;
280 
281 	switch (state) {
282 	case PM_SUSPEND_STANDBY:
283 	case PM_SUSPEND_MEM:
284 		ret = omap2_pm_suspend();
285 		break;
286 	default:
287 		ret = -EINVAL;
288 	}
289 
290 	return ret;
291 }
292 
omap2_pm_end(void)293 static void omap2_pm_end(void)
294 {
295 	suspend_state = PM_SUSPEND_ON;
296 	enable_hlt();
297 }
298 
299 static const struct platform_suspend_ops omap_pm_ops = {
300 	.begin		= omap2_pm_begin,
301 	.enter		= omap2_pm_enter,
302 	.end		= omap2_pm_end,
303 	.valid		= suspend_valid_only_mem,
304 };
305 #else
306 static const struct platform_suspend_ops __initdata omap_pm_ops;
307 #endif /* CONFIG_SUSPEND */
308 
309 /* XXX This function should be shareable between OMAP2xxx and OMAP3 */
clkdms_setup(struct clockdomain * clkdm,void * unused)310 static int __init clkdms_setup(struct clockdomain *clkdm, void *unused)
311 {
312 	if (clkdm->flags & CLKDM_CAN_ENABLE_AUTO)
313 		clkdm_allow_idle(clkdm);
314 	else if (clkdm->flags & CLKDM_CAN_FORCE_SLEEP &&
315 		 atomic_read(&clkdm->usecount) == 0)
316 		clkdm_sleep(clkdm);
317 	return 0;
318 }
319 
prcm_setup_regs(void)320 static void __init prcm_setup_regs(void)
321 {
322 	int i, num_mem_banks;
323 	struct powerdomain *pwrdm;
324 
325 	/*
326 	 * Enable autoidle
327 	 * XXX This should be handled by hwmod code or PRCM init code
328 	 */
329 	omap2_prm_write_mod_reg(OMAP24XX_AUTOIDLE_MASK, OCP_MOD,
330 			  OMAP2_PRCM_SYSCONFIG_OFFSET);
331 
332 	/*
333 	 * Set CORE powerdomain memory banks to retain their contents
334 	 * during RETENTION
335 	 */
336 	num_mem_banks = pwrdm_get_mem_bank_count(core_pwrdm);
337 	for (i = 0; i < num_mem_banks; i++)
338 		pwrdm_set_mem_retst(core_pwrdm, i, PWRDM_POWER_RET);
339 
340 	/* Set CORE powerdomain's next power state to RETENTION */
341 	pwrdm_set_next_pwrst(core_pwrdm, PWRDM_POWER_RET);
342 
343 	/*
344 	 * Set MPU powerdomain's next power state to RETENTION;
345 	 * preserve logic state during retention
346 	 */
347 	pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
348 	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);
349 
350 	/* Force-power down DSP, GFX powerdomains */
351 
352 	pwrdm = clkdm_get_pwrdm(dsp_clkdm);
353 	pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
354 	clkdm_sleep(dsp_clkdm);
355 
356 	pwrdm = clkdm_get_pwrdm(gfx_clkdm);
357 	pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
358 	clkdm_sleep(gfx_clkdm);
359 
360 	/* Enable hardware-supervised idle for all clkdms */
361 	clkdm_for_each(clkdms_setup, NULL);
362 	clkdm_add_wkdep(mpu_clkdm, wkup_clkdm);
363 
364 	/* REVISIT: Configure number of 32 kHz clock cycles for sys_clk
365 	 * stabilisation */
366 	omap2_prm_write_mod_reg(15 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
367 				OMAP2_PRCM_CLKSSETUP_OFFSET);
368 
369 	/* Configure automatic voltage transition */
370 	omap2_prm_write_mod_reg(2 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
371 				OMAP2_PRCM_VOLTSETUP_OFFSET);
372 	omap2_prm_write_mod_reg(OMAP24XX_AUTO_EXTVOLT_MASK |
373 				(0x1 << OMAP24XX_SETOFF_LEVEL_SHIFT) |
374 				OMAP24XX_MEMRETCTRL_MASK |
375 				(0x1 << OMAP24XX_SETRET_LEVEL_SHIFT) |
376 				(0x0 << OMAP24XX_VOLT_LEVEL_SHIFT),
377 				OMAP24XX_GR_MOD, OMAP2_PRCM_VOLTCTRL_OFFSET);
378 
379 	/* Enable wake-up events */
380 	omap2_prm_write_mod_reg(OMAP24XX_EN_GPIOS_MASK | OMAP24XX_EN_GPT1_MASK,
381 				WKUP_MOD, PM_WKEN);
382 }
383 
omap2_pm_init(void)384 static int __init omap2_pm_init(void)
385 {
386 	u32 l;
387 
388 	if (!cpu_is_omap24xx())
389 		return -ENODEV;
390 
391 	printk(KERN_INFO "Power Management for OMAP2 initializing\n");
392 	l = omap2_prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_REVISION_OFFSET);
393 	printk(KERN_INFO "PRCM revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);
394 
395 	/* Look up important powerdomains */
396 
397 	mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
398 	if (!mpu_pwrdm)
399 		pr_err("PM: mpu_pwrdm not found\n");
400 
401 	core_pwrdm = pwrdm_lookup("core_pwrdm");
402 	if (!core_pwrdm)
403 		pr_err("PM: core_pwrdm not found\n");
404 
405 	/* Look up important clockdomains */
406 
407 	mpu_clkdm = clkdm_lookup("mpu_clkdm");
408 	if (!mpu_clkdm)
409 		pr_err("PM: mpu_clkdm not found\n");
410 
411 	wkup_clkdm = clkdm_lookup("wkup_clkdm");
412 	if (!wkup_clkdm)
413 		pr_err("PM: wkup_clkdm not found\n");
414 
415 	dsp_clkdm = clkdm_lookup("dsp_clkdm");
416 	if (!dsp_clkdm)
417 		pr_err("PM: dsp_clkdm not found\n");
418 
419 	gfx_clkdm = clkdm_lookup("gfx_clkdm");
420 	if (!gfx_clkdm)
421 		pr_err("PM: gfx_clkdm not found\n");
422 
423 
424 	osc_ck = clk_get(NULL, "osc_ck");
425 	if (IS_ERR(osc_ck)) {
426 		printk(KERN_ERR "could not get osc_ck\n");
427 		return -ENODEV;
428 	}
429 
430 	if (cpu_is_omap242x()) {
431 		emul_ck = clk_get(NULL, "emul_ck");
432 		if (IS_ERR(emul_ck)) {
433 			printk(KERN_ERR "could not get emul_ck\n");
434 			clk_put(osc_ck);
435 			return -ENODEV;
436 		}
437 	}
438 
439 	prcm_setup_regs();
440 
441 	/* Hack to prevent MPU retention when STI console is enabled. */
442 	{
443 		const struct omap_sti_console_config *sti;
444 
445 		sti = omap_get_config(OMAP_TAG_STI_CONSOLE,
446 				      struct omap_sti_console_config);
447 		if (sti != NULL && sti->enable)
448 			sti_console_enabled = 1;
449 	}
450 
451 	/*
452 	 * We copy the assembler sleep/wakeup routines to SRAM.
453 	 * These routines need to be in SRAM as that's the only
454 	 * memory the MPU can see when it wakes up.
455 	 */
456 	if (cpu_is_omap24xx()) {
457 		omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend,
458 						 omap24xx_idle_loop_suspend_sz);
459 
460 		omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend,
461 						    omap24xx_cpu_suspend_sz);
462 	}
463 
464 	suspend_set_ops(&omap_pm_ops);
465 	pm_idle = omap2_pm_idle;
466 
467 	return 0;
468 }
469 
470 late_initcall(omap2_pm_init);
471