1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * (C) Copyright 2001
4 * Denis Peter MPL AG Switzerland. d.peter@mpl.ch
5 */
6
7/*
8 * Date & Time support for the MC146818 (PIXX4) RTC
9 */
10
11#include <command.h>
12#include <dm.h>
13#include <rtc.h>
14
15#if defined(CONFIG_X86) || defined(CONFIG_TARGET_MALTA)
16#include <asm/io.h>
17#define in8(p) inb(p)
18#define out8(p, v) outb(v, p)
19#endif
20
21/* Set this to 1 to clear the CMOS RAM */
22#define CLEAR_CMOS		0
23
24#define RTC_PORT_MC146818	0x70
25#define RTC_SECONDS		0x00
26#define RTC_SECONDS_ALARM	0x01
27#define RTC_MINUTES		0x02
28#define RTC_MINUTES_ALARM	0x03
29#define RTC_HOURS		0x04
30#define RTC_HOURS_ALARM		0x05
31#define RTC_DAY_OF_WEEK		0x06
32#define RTC_DATE_OF_MONTH	0x07
33#define RTC_MONTH		0x08
34#define RTC_YEAR		0x09
35#define RTC_CONFIG_A		0x0a
36#define RTC_CONFIG_B		0x0b
37#define RTC_CONFIG_C		0x0c
38#define RTC_CONFIG_D		0x0d
39#define RTC_REG_SIZE		0x80
40
41#define RTC_CONFIG_A_REF_CLCK_32KHZ	(1 << 5)
42#define RTC_CONFIG_A_RATE_1024HZ	6
43
44#define RTC_CONFIG_B_24H		(1 << 1)
45
46#define RTC_CONFIG_D_VALID_RAM_AND_TIME	0x80
47
48static int mc146818_read8(int reg)
49{
50#ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
51	return in8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg);
52#else
53	int ofs = 0;
54
55	if (reg >= 128) {
56		ofs = 2;
57		reg -= 128;
58	}
59	out8(RTC_PORT_MC146818 + ofs, reg);
60
61	return in8(RTC_PORT_MC146818 + ofs + 1);
62#endif
63}
64
65static void mc146818_write8(int reg, uchar val)
66{
67#ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
68	out8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg, val);
69#else
70	int ofs = 0;
71
72	if (reg >= 128) {
73		ofs = 2;
74		reg -= 128;
75	}
76	out8(RTC_PORT_MC146818 + ofs, reg);
77	out8(RTC_PORT_MC146818 + ofs + 1, val);
78#endif
79}
80
81static int mc146818_get(struct rtc_time *tmp)
82{
83	uchar sec, min, hour, mday, wday __attribute__((unused)),mon, year;
84
85	/* here check if rtc can be accessed */
86	while ((mc146818_read8(RTC_CONFIG_A) & 0x80) == 0x80)
87		;
88
89	sec	= mc146818_read8(RTC_SECONDS);
90	min	= mc146818_read8(RTC_MINUTES);
91	hour	= mc146818_read8(RTC_HOURS);
92	mday	= mc146818_read8(RTC_DATE_OF_MONTH);
93	wday	= mc146818_read8(RTC_DAY_OF_WEEK);
94	mon	= mc146818_read8(RTC_MONTH);
95	year	= mc146818_read8(RTC_YEAR);
96#ifdef RTC_DEBUG
97	printf("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x hr: %02x min: %02x sec: %02x\n",
98	       year, mon, mday, wday, hour, min, sec);
99	printf("Alarms: mday: %02x hour: %02x min: %02x sec: %02x\n",
100	       mc146818_read8(RTC_CONFIG_D) & 0x3f,
101	       mc146818_read8(RTC_HOURS_ALARM),
102	       mc146818_read8(RTC_MINUTES_ALARM),
103	       mc146818_read8(RTC_SECONDS_ALARM));
104#endif
105	tmp->tm_sec  = bcd2bin(sec & 0x7f);
106	tmp->tm_min  = bcd2bin(min & 0x7f);
107	tmp->tm_hour = bcd2bin(hour & 0x3f);
108	tmp->tm_mday = bcd2bin(mday & 0x3f);
109	tmp->tm_mon  = bcd2bin(mon & 0x1f);
110	tmp->tm_year = bcd2bin(year);
111
112	if (tmp->tm_year < 70)
113		tmp->tm_year += 2000;
114	else
115		tmp->tm_year += 1900;
116
117	tmp->tm_yday = 0;
118	tmp->tm_isdst = 0;
119	/*
120	 * The mc146818 only updates wday if it is non-zero, sunday is 1
121	 * saturday is 7. So let's use our library routine.
122	 */
123	rtc_calc_weekday(tmp);
124#ifdef RTC_DEBUG
125	printf("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
126	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
127	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
128#endif
129
130	return 0;
131}
132
133static int mc146818_set(struct rtc_time *tmp)
134{
135#ifdef RTC_DEBUG
136	printf("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
137	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
138	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
139#endif
140	/* Disable the RTC to update the regs */
141	mc146818_write8(RTC_CONFIG_B, 0x82);
142
143	mc146818_write8(RTC_YEAR, bin2bcd(tmp->tm_year % 100));
144	mc146818_write8(RTC_MONTH, bin2bcd(tmp->tm_mon));
145	/* Sunday = 1, Saturday = 7 */
146	mc146818_write8(RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday + 1));
147	mc146818_write8(RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
148	mc146818_write8(RTC_HOURS, bin2bcd(tmp->tm_hour));
149	mc146818_write8(RTC_MINUTES, bin2bcd(tmp->tm_min));
150	mc146818_write8(RTC_SECONDS, bin2bcd(tmp->tm_sec));
151
152	/* Enable the RTC to update the regs */
153	mc146818_write8(RTC_CONFIG_B, 0x02);
154
155	return 0;
156}
157
158static void mc146818_reset(void)
159{
160	/* Disable the RTC to update the regs */
161	mc146818_write8(RTC_CONFIG_B, 0x82);
162
163	/* Normal OP */
164	mc146818_write8(RTC_CONFIG_A, 0x20);
165	mc146818_write8(RTC_CONFIG_B, 0x00);
166	mc146818_write8(RTC_CONFIG_B, 0x00);
167
168	/* Enable the RTC to update the regs */
169	mc146818_write8(RTC_CONFIG_B, 0x02);
170}
171
172static void mc146818_init(void)
173{
174#if CLEAR_CMOS
175	int i;
176
177	rtc_write8(RTC_SECONDS_ALARM, 0);
178	rtc_write8(RTC_MINUTES_ALARM, 0);
179	rtc_write8(RTC_HOURS_ALARM, 0);
180	for (i = RTC_CONFIG_A; i < RTC_REG_SIZE; i++)
181		rtc_write8(i, 0);
182	printf("RTC: zeroing CMOS RAM\n");
183#endif
184
185	/* Setup the real time clock */
186	mc146818_write8(RTC_CONFIG_B, RTC_CONFIG_B_24H);
187	/* Setup the frequency it operates at */
188	mc146818_write8(RTC_CONFIG_A, RTC_CONFIG_A_REF_CLCK_32KHZ |
189			RTC_CONFIG_A_RATE_1024HZ);
190	/* Ensure all reserved bits are 0 in register D */
191	mc146818_write8(RTC_CONFIG_D, RTC_CONFIG_D_VALID_RAM_AND_TIME);
192
193	/* Clear any pending interrupts */
194	mc146818_read8(RTC_CONFIG_C);
195}
196
197#ifdef CONFIG_DM_RTC
198
199static int rtc_mc146818_get(struct udevice *dev, struct rtc_time *time)
200{
201	return mc146818_get(time);
202}
203
204static int rtc_mc146818_set(struct udevice *dev, const struct rtc_time *time)
205{
206	return mc146818_set((struct rtc_time *)time);
207}
208
209static int rtc_mc146818_reset(struct udevice *dev)
210{
211	mc146818_reset();
212
213	return 0;
214}
215
216static int rtc_mc146818_read8(struct udevice *dev, unsigned int reg)
217{
218	return mc146818_read8(reg);
219}
220
221static int rtc_mc146818_write8(struct udevice *dev, unsigned int reg, int val)
222{
223	mc146818_write8(reg, val);
224
225	return 0;
226}
227
228static int rtc_mc146818_probe(struct udevice *dev)
229{
230	mc146818_init();
231
232	return 0;
233}
234
235static const struct rtc_ops rtc_mc146818_ops = {
236	.get = rtc_mc146818_get,
237	.set = rtc_mc146818_set,
238	.reset = rtc_mc146818_reset,
239	.read8 = rtc_mc146818_read8,
240	.write8 = rtc_mc146818_write8,
241};
242
243static const struct udevice_id rtc_mc146818_ids[] = {
244	{ .compatible = "motorola,mc146818" },
245	{ }
246};
247
248U_BOOT_DRIVER(motorola_mc146818) = {
249	.name = "motorola_mc146818",
250	.id = UCLASS_RTC,
251	.of_match = rtc_mc146818_ids,
252	.probe = rtc_mc146818_probe,
253	.ops = &rtc_mc146818_ops,
254};
255
256#else /* !CONFIG_DM_RTC */
257
258int rtc_get(struct rtc_time *tmp)
259{
260	return mc146818_get(tmp);
261}
262
263int rtc_set(struct rtc_time *tmp)
264{
265	return mc146818_set(tmp);
266}
267
268void rtc_reset(void)
269{
270	mc146818_reset();
271}
272
273int rtc_read8(int reg)
274{
275	return mc146818_read8(reg);
276}
277
278void rtc_write8(int reg, uchar val)
279{
280	mc146818_write8(reg, val);
281}
282
283u32 rtc_read32(int reg)
284{
285	u32 value = 0;
286	int i;
287
288	for (i = 0; i < sizeof(value); i++)
289		value |= rtc_read8(reg + i) << (i << 3);
290
291	return value;
292}
293
294void rtc_write32(int reg, u32 value)
295{
296	int i;
297
298	for (i = 0; i < sizeof(value); i++)
299		rtc_write8(reg + i, (value >> (i << 3)) & 0xff);
300}
301
302void rtc_init(void)
303{
304	mc146818_init();
305}
306
307#endif /* CONFIG_DM_RTC */
308