xref: /rk3399_ARM-atf/plat/mediatek/mt8173/drivers/rtc/rtc.c (revision 7d116dccab2249a692181ba9521a52277e86591c)
1*7d116dccSCC Ma /*
2*7d116dccSCC Ma  * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
3*7d116dccSCC Ma  *
4*7d116dccSCC Ma  * Redistribution and use in source and binary forms, with or without
5*7d116dccSCC Ma  * modification, are permitted provided that the following conditions are met:
6*7d116dccSCC Ma  *
7*7d116dccSCC Ma  * Redistributions of source code must retain the above copyright notice, this
8*7d116dccSCC Ma  * list of conditions and the following disclaimer.
9*7d116dccSCC Ma  *
10*7d116dccSCC Ma  * Redistributions in binary form must reproduce the above copyright notice,
11*7d116dccSCC Ma  * this list of conditions and the following disclaimer in the documentation
12*7d116dccSCC Ma  * and/or other materials provided with the distribution.
13*7d116dccSCC Ma  *
14*7d116dccSCC Ma  * Neither the name of ARM nor the names of its contributors may be used
15*7d116dccSCC Ma  * to endorse or promote products derived from this software without specific
16*7d116dccSCC Ma  * prior written permission.
17*7d116dccSCC Ma  *
18*7d116dccSCC Ma  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19*7d116dccSCC Ma  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20*7d116dccSCC Ma  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21*7d116dccSCC Ma  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22*7d116dccSCC Ma  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23*7d116dccSCC Ma  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24*7d116dccSCC Ma  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25*7d116dccSCC Ma  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26*7d116dccSCC Ma  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27*7d116dccSCC Ma  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28*7d116dccSCC Ma  * POSSIBILITY OF SUCH DAMAGE.
29*7d116dccSCC Ma  */
30*7d116dccSCC Ma #include <assert.h>
31*7d116dccSCC Ma #include <debug.h>
32*7d116dccSCC Ma #include <delay_timer.h>
33*7d116dccSCC Ma #include <mt8173_def.h>
34*7d116dccSCC Ma #include <pmic_wrap_init.h>
35*7d116dccSCC Ma #include <rtc.h>
36*7d116dccSCC Ma 
37*7d116dccSCC Ma /* RTC busy status polling interval and retry count */
38*7d116dccSCC Ma enum {
39*7d116dccSCC Ma 	RTC_WRTGR_POLLING_DELAY_MS	= 10,
40*7d116dccSCC Ma 	RTC_WRTGR_POLLING_CNT		= 100
41*7d116dccSCC Ma };
42*7d116dccSCC Ma 
43*7d116dccSCC Ma static uint16_t RTC_Read(uint32_t addr)
44*7d116dccSCC Ma {
45*7d116dccSCC Ma 	uint32_t rdata = 0;
46*7d116dccSCC Ma 
47*7d116dccSCC Ma 	pwrap_read((uint32_t)addr, &rdata);
48*7d116dccSCC Ma 	return (uint16_t)rdata;
49*7d116dccSCC Ma }
50*7d116dccSCC Ma 
51*7d116dccSCC Ma static void RTC_Write(uint32_t addr, uint16_t data)
52*7d116dccSCC Ma {
53*7d116dccSCC Ma 	pwrap_write((uint32_t)addr, (uint32_t)data);
54*7d116dccSCC Ma }
55*7d116dccSCC Ma 
56*7d116dccSCC Ma static inline int32_t rtc_busy_wait(void)
57*7d116dccSCC Ma {
58*7d116dccSCC Ma 	uint64_t retry = RTC_WRTGR_POLLING_CNT;
59*7d116dccSCC Ma 
60*7d116dccSCC Ma 	do {
61*7d116dccSCC Ma 		mdelay(RTC_WRTGR_POLLING_DELAY_MS);
62*7d116dccSCC Ma 		if (!(RTC_Read(RTC_BBPU) & RTC_BBPU_CBUSY))
63*7d116dccSCC Ma 			return 1;
64*7d116dccSCC Ma 		retry--;
65*7d116dccSCC Ma 	} while (retry);
66*7d116dccSCC Ma 
67*7d116dccSCC Ma 	ERROR("[RTC] rtc cbusy time out!\n");
68*7d116dccSCC Ma 	return 0;
69*7d116dccSCC Ma }
70*7d116dccSCC Ma 
71*7d116dccSCC Ma static int32_t Write_trigger(void)
72*7d116dccSCC Ma {
73*7d116dccSCC Ma 	RTC_Write(RTC_WRTGR, 1);
74*7d116dccSCC Ma 	return rtc_busy_wait();
75*7d116dccSCC Ma }
76*7d116dccSCC Ma 
77*7d116dccSCC Ma static int32_t Writeif_unlock(void)
78*7d116dccSCC Ma {
79*7d116dccSCC Ma 	RTC_Write(RTC_PROT, RTC_PROT_UNLOCK1);
80*7d116dccSCC Ma 	if (!Write_trigger())
81*7d116dccSCC Ma 		return 0;
82*7d116dccSCC Ma 	RTC_Write(RTC_PROT, RTC_PROT_UNLOCK2);
83*7d116dccSCC Ma 	if (!Write_trigger())
84*7d116dccSCC Ma 		return 0;
85*7d116dccSCC Ma 
86*7d116dccSCC Ma 	return 1;
87*7d116dccSCC Ma }
88*7d116dccSCC Ma 
89*7d116dccSCC Ma void rtc_bbpu_power_down(void)
90*7d116dccSCC Ma {
91*7d116dccSCC Ma 	uint16_t bbpu;
92*7d116dccSCC Ma 
93*7d116dccSCC Ma 	/* pull PWRBB low */
94*7d116dccSCC Ma 	bbpu = RTC_BBPU_KEY | RTC_BBPU_AUTO | RTC_BBPU_PWREN;
95*7d116dccSCC Ma 	if (Writeif_unlock()) {
96*7d116dccSCC Ma 		RTC_Write(RTC_BBPU, bbpu);
97*7d116dccSCC Ma 		if (!Write_trigger())
98*7d116dccSCC Ma 			assert(1);
99*7d116dccSCC Ma 	} else {
100*7d116dccSCC Ma 		assert(1);
101*7d116dccSCC Ma 	}
102*7d116dccSCC Ma }
103