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
mc146818_read8(int reg)48 static 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
mc146818_write8(int reg,uchar val)65 static 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
mc146818_get(struct rtc_time * tmp)81 static 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
mc146818_set(struct rtc_time * tmp)133 static 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
mc146818_reset(void)158 static 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
mc146818_init(void)172 static 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
rtc_mc146818_get(struct udevice * dev,struct rtc_time * time)199 static int rtc_mc146818_get(struct udevice *dev, struct rtc_time *time)
200 {
201 return mc146818_get(time);
202 }
203
rtc_mc146818_set(struct udevice * dev,const struct rtc_time * time)204 static int rtc_mc146818_set(struct udevice *dev, const struct rtc_time *time)
205 {
206 return mc146818_set((struct rtc_time *)time);
207 }
208
rtc_mc146818_reset(struct udevice * dev)209 static int rtc_mc146818_reset(struct udevice *dev)
210 {
211 mc146818_reset();
212
213 return 0;
214 }
215
rtc_mc146818_read8(struct udevice * dev,unsigned int reg)216 static int rtc_mc146818_read8(struct udevice *dev, unsigned int reg)
217 {
218 return mc146818_read8(reg);
219 }
220
rtc_mc146818_write8(struct udevice * dev,unsigned int reg,int val)221 static int rtc_mc146818_write8(struct udevice *dev, unsigned int reg, int val)
222 {
223 mc146818_write8(reg, val);
224
225 return 0;
226 }
227
rtc_mc146818_probe(struct udevice * dev)228 static int rtc_mc146818_probe(struct udevice *dev)
229 {
230 mc146818_init();
231
232 return 0;
233 }
234
235 static 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
243 static const struct udevice_id rtc_mc146818_ids[] = {
244 { .compatible = "motorola,mc146818" },
245 { }
246 };
247
248 U_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
rtc_get(struct rtc_time * tmp)258 int rtc_get(struct rtc_time *tmp)
259 {
260 return mc146818_get(tmp);
261 }
262
rtc_set(struct rtc_time * tmp)263 int rtc_set(struct rtc_time *tmp)
264 {
265 return mc146818_set(tmp);
266 }
267
rtc_reset(void)268 void rtc_reset(void)
269 {
270 mc146818_reset();
271 }
272
rtc_read8(int reg)273 int rtc_read8(int reg)
274 {
275 return mc146818_read8(reg);
276 }
277
rtc_write8(int reg,uchar val)278 void rtc_write8(int reg, uchar val)
279 {
280 mc146818_write8(reg, val);
281 }
282
rtc_read32(int reg)283 u32 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
rtc_write32(int reg,u32 value)294 void 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
rtc_init(void)302 void rtc_init(void)
303 {
304 mc146818_init();
305 }
306
307 #endif /* CONFIG_DM_RTC */
308