xref: /linux/arch/arm/mach-omap2/prm44xx.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP4 PRM module functions
4  *
5  * Copyright (C) 2011-2012 Texas Instruments, Inc.
6  * Copyright (C) 2010 Nokia Corporation
7  * Benoît Cousson
8  * Paul Walmsley
9  * Rajendra Nayak <rnayak@ti.com>
10  */
11 
12 #include <linux/cpu_pm.h>
13 #include <linux/kernel.h>
14 #include <linux/delay.h>
15 #include <linux/errno.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/of_irq.h>
19 #include <linux/of.h>
20 
21 #include "soc.h"
22 #include "iomap.h"
23 #include "common.h"
24 #include "vp.h"
25 #include "prm44xx.h"
26 #include "prcm43xx.h"
27 #include "prm-regbits-44xx.h"
28 #include "prcm44xx.h"
29 #include "prminst44xx.h"
30 #include "powerdomain.h"
31 #include "pm.h"
32 
33 /* Static data */
34 
35 static void omap44xx_prm_read_pending_irqs(unsigned long *events);
36 static void omap44xx_prm_ocp_barrier(void);
37 static void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask);
38 static void omap44xx_prm_restore_irqen(u32 *saved_mask);
39 static void omap44xx_prm_reconfigure_io_chain(void);
40 
41 static const struct omap_prcm_irq omap4_prcm_irqs[] = {
42 	OMAP_PRCM_IRQ("io",     9,      1),
43 };
44 
45 static struct omap_prcm_irq_setup omap4_prcm_irq_setup = {
46 	.ack			= OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
47 	.mask			= OMAP4_PRM_IRQENABLE_MPU_OFFSET,
48 	.pm_ctrl		= OMAP4_PRM_IO_PMCTRL_OFFSET,
49 	.nr_regs		= 2,
50 	.irqs			= omap4_prcm_irqs,
51 	.nr_irqs		= ARRAY_SIZE(omap4_prcm_irqs),
52 	.read_pending_irqs	= &omap44xx_prm_read_pending_irqs,
53 	.ocp_barrier		= &omap44xx_prm_ocp_barrier,
54 	.save_and_clear_irqen	= &omap44xx_prm_save_and_clear_irqen,
55 	.restore_irqen		= &omap44xx_prm_restore_irqen,
56 	.reconfigure_io_chain	= &omap44xx_prm_reconfigure_io_chain,
57 };
58 
59 struct omap_prm_irq_context {
60 	unsigned long irq_enable;
61 	unsigned long pm_ctrl;
62 };
63 
64 static struct omap_prm_irq_context omap_prm_context;
65 
66 /*
67  * omap44xx_prm_reset_src_map - map from bits in the PRM_RSTST
68  *   hardware register (which are specific to OMAP44xx SoCs) to reset
69  *   source ID bit shifts (which is an OMAP SoC-independent
70  *   enumeration)
71  */
72 static struct prm_reset_src_map omap44xx_prm_reset_src_map[] = {
73 	{ OMAP4430_GLOBAL_WARM_SW_RST_SHIFT,
74 	  OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT },
75 	{ OMAP4430_GLOBAL_COLD_RST_SHIFT,
76 	  OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT },
77 	{ OMAP4430_MPU_SECURITY_VIOL_RST_SHIFT,
78 	  OMAP_SECU_VIOL_RST_SRC_ID_SHIFT },
79 	{ OMAP4430_MPU_WDT_RST_SHIFT, OMAP_MPU_WD_RST_SRC_ID_SHIFT },
80 	{ OMAP4430_SECURE_WDT_RST_SHIFT, OMAP_SECU_WD_RST_SRC_ID_SHIFT },
81 	{ OMAP4430_EXTERNAL_WARM_RST_SHIFT, OMAP_EXTWARM_RST_SRC_ID_SHIFT },
82 	{ OMAP4430_VDD_MPU_VOLT_MGR_RST_SHIFT,
83 	  OMAP_VDD_MPU_VM_RST_SRC_ID_SHIFT },
84 	{ OMAP4430_VDD_IVA_VOLT_MGR_RST_SHIFT,
85 	  OMAP_VDD_IVA_VM_RST_SRC_ID_SHIFT },
86 	{ OMAP4430_VDD_CORE_VOLT_MGR_RST_SHIFT,
87 	  OMAP_VDD_CORE_VM_RST_SRC_ID_SHIFT },
88 	{ OMAP4430_ICEPICK_RST_SHIFT, OMAP_ICEPICK_RST_SRC_ID_SHIFT },
89 	{ OMAP4430_C2C_RST_SHIFT, OMAP_C2C_RST_SRC_ID_SHIFT },
90 	{ -1, -1 },
91 };
92 
93 /* PRM low-level functions */
94 
95 /* Read a register in a CM/PRM instance in the PRM module */
96 static u32 omap4_prm_read_inst_reg(s16 inst, u16 reg)
97 {
98 	return readl_relaxed(prm_base.va + inst + reg);
99 }
100 
101 /* Write into a register in a CM/PRM instance in the PRM module */
102 static void omap4_prm_write_inst_reg(u32 val, s16 inst, u16 reg)
103 {
104 	writel_relaxed(val, prm_base.va + inst + reg);
105 }
106 
107 /* Read-modify-write a register in a PRM module. Caller must lock */
108 static u32 omap4_prm_rmw_inst_reg_bits(u32 mask, u32 bits, s16 inst, s16 reg)
109 {
110 	u32 v;
111 
112 	v = omap4_prm_read_inst_reg(inst, reg);
113 	v &= ~mask;
114 	v |= bits;
115 	omap4_prm_write_inst_reg(v, inst, reg);
116 
117 	return v;
118 }
119 
120 /* PRM VP */
121 
122 /*
123  * struct omap4_vp - OMAP4 VP register access description.
124  * @irqstatus_mpu: offset to IRQSTATUS_MPU register for VP
125  * @tranxdone_status: VP_TRANXDONE_ST bitmask in PRM_IRQSTATUS_MPU reg
126  */
127 struct omap4_vp {
128 	u32 irqstatus_mpu;
129 	u32 tranxdone_status;
130 };
131 
132 static struct omap4_vp omap4_vp[] = {
133 	[OMAP4_VP_VDD_MPU_ID] = {
134 		.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET,
135 		.tranxdone_status = OMAP4430_VP_MPU_TRANXDONE_ST_MASK,
136 	},
137 	[OMAP4_VP_VDD_IVA_ID] = {
138 		.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
139 		.tranxdone_status = OMAP4430_VP_IVA_TRANXDONE_ST_MASK,
140 	},
141 	[OMAP4_VP_VDD_CORE_ID] = {
142 		.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
143 		.tranxdone_status = OMAP4430_VP_CORE_TRANXDONE_ST_MASK,
144 	},
145 };
146 
147 static u32 omap4_prm_vp_check_txdone(u8 vp_id)
148 {
149 	struct omap4_vp *vp = &omap4_vp[vp_id];
150 	u32 irqstatus;
151 
152 	irqstatus = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
153 						OMAP4430_PRM_OCP_SOCKET_INST,
154 						vp->irqstatus_mpu);
155 	return irqstatus & vp->tranxdone_status;
156 }
157 
158 static void omap4_prm_vp_clear_txdone(u8 vp_id)
159 {
160 	struct omap4_vp *vp = &omap4_vp[vp_id];
161 
162 	omap4_prminst_write_inst_reg(vp->tranxdone_status,
163 				     OMAP4430_PRM_PARTITION,
164 				     OMAP4430_PRM_OCP_SOCKET_INST,
165 				     vp->irqstatus_mpu);
166 };
167 
168 u32 omap4_prm_vcvp_read(u8 offset)
169 {
170 	s32 inst = omap4_prmst_get_prm_dev_inst();
171 
172 	if (inst == PRM_INSTANCE_UNKNOWN)
173 		return 0;
174 
175 	return omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
176 					   inst, offset);
177 }
178 
179 void omap4_prm_vcvp_write(u32 val, u8 offset)
180 {
181 	s32 inst = omap4_prmst_get_prm_dev_inst();
182 
183 	if (inst == PRM_INSTANCE_UNKNOWN)
184 		return;
185 
186 	omap4_prminst_write_inst_reg(val, OMAP4430_PRM_PARTITION,
187 				     inst, offset);
188 }
189 
190 u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset)
191 {
192 	s32 inst = omap4_prmst_get_prm_dev_inst();
193 
194 	if (inst == PRM_INSTANCE_UNKNOWN)
195 		return 0;
196 
197 	return omap4_prminst_rmw_inst_reg_bits(mask, bits,
198 					       OMAP4430_PRM_PARTITION,
199 					       inst,
200 					       offset);
201 }
202 
203 static inline u32 _read_pending_irq_reg(u16 irqen_offs, u16 irqst_offs)
204 {
205 	u32 mask, st;
206 
207 	/* XXX read mask from RAM? */
208 	mask = omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
209 				       irqen_offs);
210 	st = omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST, irqst_offs);
211 
212 	return mask & st;
213 }
214 
215 /**
216  * omap44xx_prm_read_pending_irqs - read pending PRM MPU IRQs into @events
217  * @events: ptr to two consecutive u32s, preallocated by caller
218  *
219  * Read PRM_IRQSTATUS_MPU* bits, AND'ed with the currently-enabled PRM
220  * MPU IRQs, and store the result into the two u32s pointed to by @events.
221  * No return value.
222  */
223 static void omap44xx_prm_read_pending_irqs(unsigned long *events)
224 {
225 	int i;
226 
227 	for (i = 0; i < omap4_prcm_irq_setup.nr_regs; i++)
228 		events[i] = _read_pending_irq_reg(omap4_prcm_irq_setup.mask +
229 				i * 4, omap4_prcm_irq_setup.ack + i * 4);
230 }
231 
232 /**
233  * omap44xx_prm_ocp_barrier - force buffered MPU writes to the PRM to complete
234  *
235  * Force any buffered writes to the PRM IP block to complete.  Needed
236  * by the PRM IRQ handler, which reads and writes directly to the IP
237  * block, to avoid race conditions after acknowledging or clearing IRQ
238  * bits.  No return value.
239  */
240 static void omap44xx_prm_ocp_barrier(void)
241 {
242 	omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
243 				OMAP4_REVISION_PRM_OFFSET);
244 }
245 
246 /**
247  * omap44xx_prm_save_and_clear_irqen - save/clear PRM_IRQENABLE_MPU* regs
248  * @saved_mask: ptr to a u32 array to save IRQENABLE bits
249  *
250  * Save the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers to
251  * @saved_mask.  @saved_mask must be allocated by the caller.
252  * Intended to be used in the PRM interrupt handler suspend callback.
253  * The OCP barrier is needed to ensure the write to disable PRM
254  * interrupts reaches the PRM before returning; otherwise, spurious
255  * interrupts might occur.  No return value.
256  */
257 static void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask)
258 {
259 	int i;
260 	u16 reg;
261 
262 	for (i = 0; i < omap4_prcm_irq_setup.nr_regs; i++) {
263 		reg = omap4_prcm_irq_setup.mask + i * 4;
264 
265 		saved_mask[i] =
266 			omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
267 						reg);
268 		omap4_prm_write_inst_reg(0, OMAP4430_PRM_OCP_SOCKET_INST, reg);
269 	}
270 
271 	/* OCP barrier */
272 	omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
273 				OMAP4_REVISION_PRM_OFFSET);
274 }
275 
276 /**
277  * omap44xx_prm_restore_irqen - set PRM_IRQENABLE_MPU* registers from args
278  * @saved_mask: ptr to a u32 array of IRQENABLE bits saved previously
279  *
280  * Restore the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers from
281  * @saved_mask.  Intended to be used in the PRM interrupt handler resume
282  * callback to restore values saved by omap44xx_prm_save_and_clear_irqen().
283  * No OCP barrier should be needed here; any pending PRM interrupts will fire
284  * once the writes reach the PRM.  No return value.
285  */
286 static void omap44xx_prm_restore_irqen(u32 *saved_mask)
287 {
288 	int i;
289 
290 	for (i = 0; i < omap4_prcm_irq_setup.nr_regs; i++)
291 		omap4_prm_write_inst_reg(saved_mask[i],
292 					 OMAP4430_PRM_OCP_SOCKET_INST,
293 					 omap4_prcm_irq_setup.mask + i * 4);
294 }
295 
296 /**
297  * omap44xx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
298  *
299  * Clear any previously-latched I/O wakeup events and ensure that the
300  * I/O wakeup gates are aligned with the current mux settings.  Works
301  * by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
302  * deasserting WUCLKIN and waiting for WUCLKOUT to be deasserted.
303  * No return value. XXX Are the final two steps necessary?
304  */
305 static void omap44xx_prm_reconfigure_io_chain(void)
306 {
307 	int i = 0;
308 	s32 inst = omap4_prmst_get_prm_dev_inst();
309 
310 	if (inst == PRM_INSTANCE_UNKNOWN)
311 		return;
312 
313 	/* Trigger WUCLKIN enable */
314 	omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK,
315 				    OMAP4430_WUCLK_CTRL_MASK,
316 				    inst,
317 				    omap4_prcm_irq_setup.pm_ctrl);
318 	omap_test_timeout(
319 		(((omap4_prm_read_inst_reg(inst,
320 					   omap4_prcm_irq_setup.pm_ctrl) &
321 		   OMAP4430_WUCLK_STATUS_MASK) >>
322 		  OMAP4430_WUCLK_STATUS_SHIFT) == 1),
323 		MAX_IOPAD_LATCH_TIME, i);
324 	if (i == MAX_IOPAD_LATCH_TIME)
325 		pr_warn("PRM: I/O chain clock line assertion timed out\n");
326 
327 	/* Trigger WUCLKIN disable */
328 	omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK, 0x0,
329 				    inst,
330 				    omap4_prcm_irq_setup.pm_ctrl);
331 	omap_test_timeout(
332 		(((omap4_prm_read_inst_reg(inst,
333 					   omap4_prcm_irq_setup.pm_ctrl) &
334 		   OMAP4430_WUCLK_STATUS_MASK) >>
335 		  OMAP4430_WUCLK_STATUS_SHIFT) == 0),
336 		MAX_IOPAD_LATCH_TIME, i);
337 	if (i == MAX_IOPAD_LATCH_TIME)
338 		pr_warn("PRM: I/O chain clock line deassertion timed out\n");
339 
340 	return;
341 }
342 
343 /**
344  * omap44xx_prm_enable_io_wakeup - enable wakeup events from I/O wakeup latches
345  *
346  * Activates the I/O wakeup event latches and allows events logged by
347  * those latches to signal a wakeup event to the PRCM.  For I/O wakeups
348  * to occur, WAKEUPENABLE bits must be set in the pad mux registers, and
349  * omap44xx_prm_reconfigure_io_chain() must be called.  No return value.
350  */
351 static void omap44xx_prm_enable_io_wakeup(void)
352 {
353 	s32 inst = omap4_prmst_get_prm_dev_inst();
354 
355 	if (inst == PRM_INSTANCE_UNKNOWN)
356 		return;
357 
358 	omap4_prm_rmw_inst_reg_bits(OMAP4430_GLOBAL_WUEN_MASK,
359 				    OMAP4430_GLOBAL_WUEN_MASK,
360 				    inst,
361 				    omap4_prcm_irq_setup.pm_ctrl);
362 }
363 
364 /**
365  * omap44xx_prm_read_reset_sources - return the last SoC reset source
366  *
367  * Return a u32 representing the last reset sources of the SoC.  The
368  * returned reset source bits are standardized across OMAP SoCs.
369  */
370 static u32 omap44xx_prm_read_reset_sources(void)
371 {
372 	struct prm_reset_src_map *p;
373 	u32 r = 0;
374 	u32 v;
375 	s32 inst = omap4_prmst_get_prm_dev_inst();
376 
377 	if (inst == PRM_INSTANCE_UNKNOWN)
378 		return 0;
379 
380 
381 	v = omap4_prm_read_inst_reg(inst,
382 				    OMAP4_RM_RSTST);
383 
384 	p = omap44xx_prm_reset_src_map;
385 	while (p->reg_shift >= 0 && p->std_shift >= 0) {
386 		if (v & (1 << p->reg_shift))
387 			r |= 1 << p->std_shift;
388 		p++;
389 	}
390 
391 	return r;
392 }
393 
394 /**
395  * omap44xx_prm_was_any_context_lost_old - was module hardware context lost?
396  * @part: PRM partition ID (e.g., OMAP4430_PRM_PARTITION)
397  * @inst: PRM instance offset (e.g., OMAP4430_PRM_MPU_INST)
398  * @idx: CONTEXT register offset
399  *
400  * Return 1 if any bits were set in the *_CONTEXT_* register
401  * identified by (@part, @inst, @idx), which means that some context
402  * was lost for that module; otherwise, return 0.
403  */
404 static bool omap44xx_prm_was_any_context_lost_old(u8 part, s16 inst, u16 idx)
405 {
406 	return (omap4_prminst_read_inst_reg(part, inst, idx)) ? 1 : 0;
407 }
408 
409 /**
410  * omap44xx_prm_clear_context_lost_flags_old - clear context loss flags
411  * @part: PRM partition ID (e.g., OMAP4430_PRM_PARTITION)
412  * @inst: PRM instance offset (e.g., OMAP4430_PRM_MPU_INST)
413  * @idx: CONTEXT register offset
414  *
415  * Clear hardware context loss bits for the module identified by
416  * (@part, @inst, @idx).  No return value.  XXX Writes to reserved bits;
417  * is there a way to avoid this?
418  */
419 static void omap44xx_prm_clear_context_loss_flags_old(u8 part, s16 inst,
420 						      u16 idx)
421 {
422 	omap4_prminst_write_inst_reg(0xffffffff, part, inst, idx);
423 }
424 
425 /* Powerdomain low-level functions */
426 
427 static int omap4_pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
428 {
429 	omap4_prminst_rmw_inst_reg_bits(OMAP_POWERSTATE_MASK,
430 					(pwrst << OMAP_POWERSTATE_SHIFT),
431 					pwrdm->prcm_partition,
432 					pwrdm->prcm_offs, OMAP4_PM_PWSTCTRL);
433 	return 0;
434 }
435 
436 static int omap4_pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
437 {
438 	u32 v;
439 
440 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
441 					OMAP4_PM_PWSTCTRL);
442 	v &= OMAP_POWERSTATE_MASK;
443 	v >>= OMAP_POWERSTATE_SHIFT;
444 
445 	return v;
446 }
447 
448 static int omap4_pwrdm_read_pwrst(struct powerdomain *pwrdm)
449 {
450 	u32 v;
451 
452 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
453 					OMAP4_PM_PWSTST);
454 	v &= OMAP_POWERSTATEST_MASK;
455 	v >>= OMAP_POWERSTATEST_SHIFT;
456 
457 	return v;
458 }
459 
460 static int omap4_pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
461 {
462 	u32 v;
463 
464 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
465 					OMAP4_PM_PWSTST);
466 	v &= OMAP4430_LASTPOWERSTATEENTERED_MASK;
467 	v >>= OMAP4430_LASTPOWERSTATEENTERED_SHIFT;
468 
469 	return v;
470 }
471 
472 static int omap4_pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
473 {
474 	omap4_prminst_rmw_inst_reg_bits(OMAP4430_LOWPOWERSTATECHANGE_MASK,
475 					(1 << OMAP4430_LOWPOWERSTATECHANGE_SHIFT),
476 					pwrdm->prcm_partition,
477 					pwrdm->prcm_offs, OMAP4_PM_PWSTCTRL);
478 	return 0;
479 }
480 
481 static int omap4_pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
482 {
483 	omap4_prminst_rmw_inst_reg_bits(OMAP4430_LASTPOWERSTATEENTERED_MASK,
484 					OMAP4430_LASTPOWERSTATEENTERED_MASK,
485 					pwrdm->prcm_partition,
486 					pwrdm->prcm_offs, OMAP4_PM_PWSTST);
487 	return 0;
488 }
489 
490 static int omap4_pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
491 {
492 	u32 v;
493 
494 	v = pwrst << __ffs(OMAP4430_LOGICRETSTATE_MASK);
495 	omap4_prminst_rmw_inst_reg_bits(OMAP4430_LOGICRETSTATE_MASK, v,
496 					pwrdm->prcm_partition, pwrdm->prcm_offs,
497 					OMAP4_PM_PWSTCTRL);
498 
499 	return 0;
500 }
501 
502 static int omap4_pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank,
503 				    u8 pwrst)
504 {
505 	u32 m;
506 
507 	m = omap2_pwrdm_get_mem_bank_onstate_mask(bank);
508 
509 	omap4_prminst_rmw_inst_reg_bits(m, (pwrst << __ffs(m)),
510 					pwrdm->prcm_partition, pwrdm->prcm_offs,
511 					OMAP4_PM_PWSTCTRL);
512 
513 	return 0;
514 }
515 
516 static int omap4_pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank,
517 				     u8 pwrst)
518 {
519 	u32 m;
520 
521 	m = omap2_pwrdm_get_mem_bank_retst_mask(bank);
522 
523 	omap4_prminst_rmw_inst_reg_bits(m, (pwrst << __ffs(m)),
524 					pwrdm->prcm_partition, pwrdm->prcm_offs,
525 					OMAP4_PM_PWSTCTRL);
526 
527 	return 0;
528 }
529 
530 static int omap4_pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
531 {
532 	u32 v;
533 
534 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
535 					OMAP4_PM_PWSTST);
536 	v &= OMAP4430_LOGICSTATEST_MASK;
537 	v >>= OMAP4430_LOGICSTATEST_SHIFT;
538 
539 	return v;
540 }
541 
542 static int omap4_pwrdm_read_logic_retst(struct powerdomain *pwrdm)
543 {
544 	u32 v;
545 
546 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
547 					OMAP4_PM_PWSTCTRL);
548 	v &= OMAP4430_LOGICRETSTATE_MASK;
549 	v >>= OMAP4430_LOGICRETSTATE_SHIFT;
550 
551 	return v;
552 }
553 
554 /**
555  * omap4_pwrdm_read_prev_logic_pwrst - read the previous logic powerstate
556  * @pwrdm: struct powerdomain * to read the state for
557  *
558  * Reads the previous logic powerstate for a powerdomain. This
559  * function must determine the previous logic powerstate by first
560  * checking the previous powerstate for the domain. If that was OFF,
561  * then logic has been lost. If previous state was RETENTION, the
562  * function reads the setting for the next retention logic state to
563  * see the actual value.  In every other case, the logic is
564  * retained. Returns either PWRDM_POWER_OFF or PWRDM_POWER_RET
565  * depending whether the logic was retained or not.
566  */
567 static int omap4_pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm)
568 {
569 	int state;
570 
571 	state = omap4_pwrdm_read_prev_pwrst(pwrdm);
572 
573 	if (state == PWRDM_POWER_OFF)
574 		return PWRDM_POWER_OFF;
575 
576 	if (state != PWRDM_POWER_RET)
577 		return PWRDM_POWER_RET;
578 
579 	return omap4_pwrdm_read_logic_retst(pwrdm);
580 }
581 
582 static int omap4_pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
583 {
584 	u32 m, v;
585 
586 	m = omap2_pwrdm_get_mem_bank_stst_mask(bank);
587 
588 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
589 					OMAP4_PM_PWSTST);
590 	v &= m;
591 	v >>= __ffs(m);
592 
593 	return v;
594 }
595 
596 static int omap4_pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
597 {
598 	u32 m, v;
599 
600 	m = omap2_pwrdm_get_mem_bank_retst_mask(bank);
601 
602 	v = omap4_prminst_read_inst_reg(pwrdm->prcm_partition, pwrdm->prcm_offs,
603 					OMAP4_PM_PWSTCTRL);
604 	v &= m;
605 	v >>= __ffs(m);
606 
607 	return v;
608 }
609 
610 /**
611  * omap4_pwrdm_read_prev_mem_pwrst - reads the previous memory powerstate
612  * @pwrdm: struct powerdomain * to read mem powerstate for
613  * @bank: memory bank index
614  *
615  * Reads the previous memory powerstate for a powerdomain. This
616  * function must determine the previous memory powerstate by first
617  * checking the previous powerstate for the domain. If that was OFF,
618  * then logic has been lost. If previous state was RETENTION, the
619  * function reads the setting for the next memory retention state to
620  * see the actual value.  In every other case, the logic is
621  * retained. Returns either PWRDM_POWER_OFF or PWRDM_POWER_RET
622  * depending whether logic was retained or not.
623  */
624 static int omap4_pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
625 {
626 	int state;
627 
628 	state = omap4_pwrdm_read_prev_pwrst(pwrdm);
629 
630 	if (state == PWRDM_POWER_OFF)
631 		return PWRDM_POWER_OFF;
632 
633 	if (state != PWRDM_POWER_RET)
634 		return PWRDM_POWER_RET;
635 
636 	return omap4_pwrdm_read_mem_retst(pwrdm, bank);
637 }
638 
639 static int omap4_pwrdm_wait_transition(struct powerdomain *pwrdm)
640 {
641 	u32 c = 0;
642 
643 	/*
644 	 * REVISIT: pwrdm_wait_transition() may be better implemented
645 	 * via a callback and a periodic timer check -- how long do we expect
646 	 * powerdomain transitions to take?
647 	 */
648 
649 	/* XXX Is this udelay() value meaningful? */
650 	while ((omap4_prminst_read_inst_reg(pwrdm->prcm_partition,
651 					    pwrdm->prcm_offs,
652 					    OMAP4_PM_PWSTST) &
653 		OMAP_INTRANSITION_MASK) &&
654 	       (c++ < PWRDM_TRANSITION_BAILOUT))
655 		udelay(1);
656 
657 	if (c > PWRDM_TRANSITION_BAILOUT) {
658 		pr_err("powerdomain: %s: waited too long to complete transition\n",
659 		       pwrdm->name);
660 		return -EAGAIN;
661 	}
662 
663 	pr_debug("powerdomain: completed transition in %d loops\n", c);
664 
665 	return 0;
666 }
667 
668 static int omap4_check_vcvp(void)
669 {
670 	if (prm_features & PRM_HAS_VOLTAGE)
671 		return 1;
672 
673 	return 0;
674 }
675 
676 /**
677  * omap4_pwrdm_save_context - Saves the powerdomain state
678  * @pwrdm: pointer to individual powerdomain
679  *
680  * The function saves the powerdomain state control information.
681  * This is needed in rtc+ddr modes where we lose powerdomain context.
682  */
683 static void omap4_pwrdm_save_context(struct powerdomain *pwrdm)
684 {
685 	pwrdm->context = omap4_prminst_read_inst_reg(pwrdm->prcm_partition,
686 						     pwrdm->prcm_offs,
687 						     pwrdm->pwrstctrl_offs);
688 
689 	/*
690 	 * Do not save LOWPOWERSTATECHANGE, writing a 1 indicates a request,
691 	 * reading back a 1 indicates a request in progress.
692 	 */
693 	pwrdm->context &= ~OMAP4430_LOWPOWERSTATECHANGE_MASK;
694 }
695 
696 /**
697  * omap4_pwrdm_restore_context - Restores the powerdomain state
698  * @pwrdm: pointer to individual powerdomain
699  *
700  * The function restores the powerdomain state control information.
701  * This is needed in rtc+ddr modes where we lose powerdomain context.
702  */
703 static void omap4_pwrdm_restore_context(struct powerdomain *pwrdm)
704 {
705 	int st, ctrl;
706 
707 	st = omap4_prminst_read_inst_reg(pwrdm->prcm_partition,
708 					 pwrdm->prcm_offs,
709 					 pwrdm->pwrstctrl_offs);
710 
711 	omap4_prminst_write_inst_reg(pwrdm->context,
712 				     pwrdm->prcm_partition,
713 				     pwrdm->prcm_offs,
714 				     pwrdm->pwrstctrl_offs);
715 
716 	/* Make sure we only wait for a transition if there is one */
717 	st &= OMAP_POWERSTATEST_MASK;
718 	ctrl = OMAP_POWERSTATEST_MASK & pwrdm->context;
719 
720 	if (st != ctrl)
721 		omap4_pwrdm_wait_transition(pwrdm);
722 }
723 
724 struct pwrdm_ops omap4_pwrdm_operations = {
725 	.pwrdm_set_next_pwrst	= omap4_pwrdm_set_next_pwrst,
726 	.pwrdm_read_next_pwrst	= omap4_pwrdm_read_next_pwrst,
727 	.pwrdm_read_pwrst	= omap4_pwrdm_read_pwrst,
728 	.pwrdm_read_prev_pwrst	= omap4_pwrdm_read_prev_pwrst,
729 	.pwrdm_set_lowpwrstchange	= omap4_pwrdm_set_lowpwrstchange,
730 	.pwrdm_clear_all_prev_pwrst	= omap4_pwrdm_clear_all_prev_pwrst,
731 	.pwrdm_set_logic_retst	= omap4_pwrdm_set_logic_retst,
732 	.pwrdm_read_logic_pwrst	= omap4_pwrdm_read_logic_pwrst,
733 	.pwrdm_read_prev_logic_pwrst	= omap4_pwrdm_read_prev_logic_pwrst,
734 	.pwrdm_read_logic_retst	= omap4_pwrdm_read_logic_retst,
735 	.pwrdm_read_mem_pwrst	= omap4_pwrdm_read_mem_pwrst,
736 	.pwrdm_read_mem_retst	= omap4_pwrdm_read_mem_retst,
737 	.pwrdm_read_prev_mem_pwrst	= omap4_pwrdm_read_prev_mem_pwrst,
738 	.pwrdm_set_mem_onst	= omap4_pwrdm_set_mem_onst,
739 	.pwrdm_set_mem_retst	= omap4_pwrdm_set_mem_retst,
740 	.pwrdm_wait_transition	= omap4_pwrdm_wait_transition,
741 	.pwrdm_has_voltdm	= omap4_check_vcvp,
742 	.pwrdm_save_context	= omap4_pwrdm_save_context,
743 	.pwrdm_restore_context	= omap4_pwrdm_restore_context,
744 };
745 
746 static int omap44xx_prm_late_init(void);
747 
748 void prm_save_context(void)
749 {
750 	omap_prm_context.irq_enable =
751 			omap4_prm_read_inst_reg(AM43XX_PRM_OCP_SOCKET_INST,
752 						omap4_prcm_irq_setup.mask);
753 
754 	omap_prm_context.pm_ctrl =
755 			omap4_prm_read_inst_reg(AM43XX_PRM_DEVICE_INST,
756 						omap4_prcm_irq_setup.pm_ctrl);
757 }
758 
759 void prm_restore_context(void)
760 {
761 	omap4_prm_write_inst_reg(omap_prm_context.irq_enable,
762 				 OMAP4430_PRM_OCP_SOCKET_INST,
763 				 omap4_prcm_irq_setup.mask);
764 
765 	omap4_prm_write_inst_reg(omap_prm_context.pm_ctrl,
766 				 AM43XX_PRM_DEVICE_INST,
767 				 omap4_prcm_irq_setup.pm_ctrl);
768 }
769 
770 static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
771 {
772 	switch (cmd) {
773 	case CPU_CLUSTER_PM_ENTER:
774 		if (enable_off_mode)
775 			prm_save_context();
776 		break;
777 	case CPU_CLUSTER_PM_EXIT:
778 		if (enable_off_mode)
779 			prm_restore_context();
780 		break;
781 	}
782 
783 	return NOTIFY_OK;
784 }
785 
786 /*
787  * XXX document
788  */
789 static struct prm_ll_data omap44xx_prm_ll_data = {
790 	.read_reset_sources = &omap44xx_prm_read_reset_sources,
791 	.was_any_context_lost_old = &omap44xx_prm_was_any_context_lost_old,
792 	.clear_context_loss_flags_old = &omap44xx_prm_clear_context_loss_flags_old,
793 	.late_init = &omap44xx_prm_late_init,
794 	.assert_hardreset	= omap4_prminst_assert_hardreset,
795 	.deassert_hardreset	= omap4_prminst_deassert_hardreset,
796 	.is_hardreset_asserted	= omap4_prminst_is_hardreset_asserted,
797 	.reset_system		= omap4_prminst_global_warm_sw_reset,
798 	.vp_check_txdone	= omap4_prm_vp_check_txdone,
799 	.vp_clear_txdone	= omap4_prm_vp_clear_txdone,
800 };
801 
802 static const struct omap_prcm_init_data *prm_init_data;
803 
804 int __init omap44xx_prm_init(const struct omap_prcm_init_data *data)
805 {
806 	static struct notifier_block nb;
807 	omap_prm_base_init();
808 
809 	prm_init_data = data;
810 
811 	if (data->flags & PRM_HAS_IO_WAKEUP)
812 		prm_features |= PRM_HAS_IO_WAKEUP;
813 
814 	if (data->flags & PRM_HAS_VOLTAGE)
815 		prm_features |= PRM_HAS_VOLTAGE;
816 
817 	omap4_prminst_set_prm_dev_inst(data->device_inst_offset);
818 
819 	/* Add AM437X specific differences */
820 	if (of_device_is_compatible(data->np, "ti,am4-prcm")) {
821 		omap4_prcm_irq_setup.nr_irqs = 1;
822 		omap4_prcm_irq_setup.nr_regs = 1;
823 		omap4_prcm_irq_setup.pm_ctrl = AM43XX_PRM_IO_PMCTRL_OFFSET;
824 		omap4_prcm_irq_setup.ack = AM43XX_PRM_IRQSTATUS_MPU_OFFSET;
825 		omap4_prcm_irq_setup.mask = AM43XX_PRM_IRQENABLE_MPU_OFFSET;
826 	}
827 
828 	/* Only AM43XX can lose prm context during rtc-ddr suspend */
829 	if (soc_is_am43xx()) {
830 		nb.notifier_call = cpu_notifier;
831 		cpu_pm_register_notifier(&nb);
832 	}
833 
834 	return prm_register(&omap44xx_prm_ll_data);
835 }
836 
837 static int omap44xx_prm_late_init(void)
838 {
839 	int irq_num;
840 
841 	if (!(prm_features & PRM_HAS_IO_WAKEUP))
842 		return 0;
843 
844 	irq_num = of_irq_get(prm_init_data->np, 0);
845 	if (irq_num == -EPROBE_DEFER)
846 		return irq_num;
847 
848 	omap4_prcm_irq_setup.irq = irq_num;
849 
850 	omap44xx_prm_enable_io_wakeup();
851 
852 	return omap_prcm_register_chain_handler(&omap4_prcm_irq_setup);
853 }
854 
855 static void __exit omap44xx_prm_exit(void)
856 {
857 	prm_unregister(&omap44xx_prm_ll_data);
858 }
859 __exitcall(omap44xx_prm_exit);
860