1 // SPDX-License-Identifier: GPL-2.0+
3 * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
5 * Based on a the Linux rtc-rv3029c2.c driver written by:
6 * Gregory Hermant <gregory.hermant@calao-systems.com>
7 * Michael Buesch <m@bues.ch>
17 #include <dm/device_compat.h>
19 #define RTC_RV3029_PAGE_LEN 7
22 #define RV3029_ONOFF_CTRL 0x00
23 #define RV3029_ONOFF_CTRL_WE BIT(0)
24 #define RV3029_ONOFF_CTRL_TE BIT(1)
25 #define RV3029_ONOFF_CTRL_TAR BIT(2)
26 #define RV3029_ONOFF_CTRL_EERE BIT(3)
27 #define RV3029_ONOFF_CTRL_SRON BIT(4)
28 #define RV3029_ONOFF_CTRL_TD0 BIT(5)
29 #define RV3029_ONOFF_CTRL_TD1 BIT(6)
30 #define RV3029_ONOFF_CTRL_CLKINT BIT(7)
31 #define RV3029_IRQ_CTRL 0x01
32 #define RV3029_IRQ_CTRL_AIE BIT(0)
33 #define RV3029_IRQ_CTRL_TIE BIT(1)
34 #define RV3029_IRQ_CTRL_V1IE BIT(2)
35 #define RV3029_IRQ_CTRL_V2IE BIT(3)
36 #define RV3029_IRQ_CTRL_SRIE BIT(4)
37 #define RV3029_IRQ_FLAGS 0x02
38 #define RV3029_IRQ_FLAGS_AF BIT(0)
39 #define RV3029_IRQ_FLAGS_TF BIT(1)
40 #define RV3029_IRQ_FLAGS_V1IF BIT(2)
41 #define RV3029_IRQ_FLAGS_V2IF BIT(3)
42 #define RV3029_IRQ_FLAGS_SRF BIT(4)
43 #define RV3029_STATUS 0x03
44 #define RV3029_STATUS_VLOW1 BIT(2)
45 #define RV3029_STATUS_VLOW2 BIT(3)
46 #define RV3029_STATUS_SR BIT(4)
47 #define RV3029_STATUS_PON BIT(5)
48 #define RV3029_STATUS_EEBUSY BIT(7)
49 #define RV3029_RST_CTRL 0x04
50 #define RV3029_RST_CTRL_SYSR BIT(4)
51 #define RV3029_CONTROL_SECTION_LEN 0x05
54 #define RV3029_W_SEC 0x08
55 #define RV3029_W_MINUTES 0x09
56 #define RV3029_W_HOURS 0x0A
57 #define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */
58 #define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */
59 #define RV3029_W_DATE 0x0B
60 #define RV3029_W_DAYS 0x0C
61 #define RV3029_W_MONTHS 0x0D
62 #define RV3029_W_YEARS 0x0E
64 /* eeprom control section */
65 #define RV3029_CONTROL_E2P_EECTRL 0x30
66 #define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */
67 #define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */
68 #define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */
69 #define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */
70 #define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\
74 #define RV3029_TRICKLE_SHIFT 4
77 static int rv3029_rtc_get(struct udevice *dev, struct rtc_time *tm)
79 u8 regs[RTC_RV3029_PAGE_LEN];
82 ret = dm_i2c_read(dev, RV3029_W_SEC, regs, sizeof(regs));
84 printf("%s: error reading RTC: %x\n", __func__, ret);
88 tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
89 tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
91 /* HR field has a more complex interpretation */
93 const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
95 if (_hr & RV3029_REG_HR_12_24) {
97 tm->tm_hour = bcd2bin(_hr & 0x1f);
98 if (_hr & RV3029_REG_HR_PM) /* PM flag set */
102 tm->tm_hour = bcd2bin(_hr & 0x3f);
106 tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
107 tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
108 /* RTC supports only years > 1999 */
109 tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 2000;
110 tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
115 debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
116 __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
117 tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
122 static int rv3029_rtc_set(struct udevice *dev, const struct rtc_time *tm)
124 u8 regs[RTC_RV3029_PAGE_LEN];
126 debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n",
127 __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
128 tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
131 if (tm->tm_year < 2000) {
132 printf("%s: year %d (before 2000) not supported\n",
133 __func__, tm->tm_year);
137 regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
138 regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
139 regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
140 regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
141 regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
142 regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
143 regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 2000);
145 return dm_i2c_write(dev, RV3029_W_SEC, regs, sizeof(regs));
148 static int rv3029_rtc_reset(struct udevice *dev)
150 u8 ctrl = RV3029_RST_CTRL_SYSR;
152 const unsigned long timeout_ms = 10000;
155 /* trigger the system-reset */
156 ret = dm_i2c_write(dev, RV3029_RST_CTRL, &ctrl, 1);
160 /* wait for the system-reset to complete */
161 start = get_timer(0);
163 if (get_timer(start) > timeout_ms)
166 ret = dm_i2c_read(dev, RV3029_RST_CTRL, &ctrl, 1);
169 } while (ctrl & RV3029_RST_CTRL_SYSR);
174 static int rv3029_rtc_read8(struct udevice *dev, unsigned int reg)
179 ret = dm_i2c_read(dev, reg, &data, sizeof(data));
180 return ret < 0 ? ret : data;
183 static int rv3029_rtc_write8(struct udevice *dev, unsigned int reg, int val)
187 return dm_i2c_write(dev, reg, &data, 1);
190 #if defined(OF_CONTROL)
191 static int rv3029_get_sr(struct udevice *dev, u8 *buf)
193 int ret = dm_i2c_read(dev, RV3029_STATUS, buf, 1);
198 dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
202 static int rv3029_set_sr(struct udevice *dev, u8 val)
206 ret = dm_i2c_read(dev, RV3029_STATUS, &val, 1);
210 dev_dbg(dev, "status = 0x%.2x (%d)\n", val, val);
214 static int rv3029_eeprom_busywait(struct udevice *dev)
219 for (i = 100; i > 0; i--) {
220 ret = rv3029_get_sr(dev, &sr);
223 if (!(sr & RV3029_STATUS_EEBUSY))
228 dev_err(dev, "EEPROM busy wait timeout.\n");
235 static int rv3029_update_bits(struct udevice *dev, u8 reg, u8 mask, u8 set)
240 ret = dm_i2c_read(dev, reg, &buf, 1);
244 if ((buf & mask) == (set && mask))
247 buf = (buf & ~mask) | (set & mask);
248 ret = dm_i2c_read(dev, reg, &buf, 1);
255 static int rv3029_eeprom_exit(struct udevice *dev)
257 /* Re-enable eeprom refresh */
258 return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
259 RV3029_ONOFF_CTRL_EERE,
260 RV3029_ONOFF_CTRL_EERE);
263 static int rv3029_eeprom_enter(struct udevice *dev)
268 /* Check whether we are in the allowed voltage range. */
269 ret = rv3029_get_sr(dev, &sr);
272 if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
273 /* We clear the bits and retry once just in case
274 * we had a brown out in early startup.
276 sr &= ~RV3029_STATUS_VLOW1;
277 sr &= ~RV3029_STATUS_VLOW2;
278 ret = rv3029_set_sr(dev, sr);
282 ret = rv3029_get_sr(dev, &sr);
285 if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
286 dev_err(dev, "Supply voltage is too low to safely access the EEPROM.\n");
291 /* Disable eeprom refresh. */
292 ret = rv3029_update_bits(dev,
293 RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, 0);
297 /* Wait for any previous eeprom accesses to finish. */
298 ret = rv3029_eeprom_busywait(dev);
300 rv3029_eeprom_exit(dev);
305 static int rv3029_eeprom_read(struct udevice *dev, u8 reg,
306 u8 buf[], size_t len)
310 err = rv3029_eeprom_enter(dev);
314 ret = dm_i2c_read(dev, reg, buf, len);
316 err = rv3029_eeprom_exit(dev);
323 static int rv3029_eeprom_write(struct udevice *dev, u8 reg,
324 u8 const buf[], size_t len)
330 ret = rv3029_eeprom_enter(dev);
334 for (i = 0; i < len; i++, reg++) {
335 ret = dm_i2c_read(dev, reg, &tmp, 1);
339 ret = dm_i2c_write(dev, reg, &buf[i], 1);
343 ret = rv3029_eeprom_busywait(dev);
348 ret = rv3029_eeprom_exit(dev);
355 static int rv3029_eeprom_update_bits(struct udevice *dev,
356 u8 reg, u8 mask, u8 set)
361 ret = rv3029_eeprom_read(dev, reg, &buf, 1);
366 * If the EEPROM already reads the correct bitpattern, we don't need
369 if ((buf & mask) == (set & mask))
372 buf = (buf & ~mask) | (set & mask);
373 ret = rv3029_eeprom_write(dev, reg, &buf, 1);
380 static void rv3029_trickle_config(struct udevice *dev)
382 static const struct rv3029_trickle_tab_elem {
383 u32 r; /* resistance in ohms */
384 u8 conf; /* trickle config bits */
385 } rv3029_trickle_tab[] = {
388 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
389 RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
392 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
396 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
400 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
403 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
407 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
410 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
413 .conf = RV3029_TRICKLE_1K,
416 .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
420 .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
423 .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
426 .conf = RV3029_TRICKLE_5K,
429 .conf = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
432 .conf = RV3029_TRICKLE_20K,
435 .conf = RV3029_TRICKLE_80K,
440 u8 trickle_set_bits = 0;
442 /* Configure the trickle charger. */
443 err = dev_read_u32(dev, "trickle-resistor-ohms", &ohms);
446 /* Find trickle-charger config */
447 for (int i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++)
448 if (rv3029_trickle_tab[i].r >= ohms) {
449 dev_dbg(dev, "trickle charger at %d ohms\n",
450 rv3029_trickle_tab[i].r);
451 trickle_set_bits = rv3029_trickle_tab[i].conf;
456 dev_dbg(dev, "trickle charger config 0x%x\n", trickle_set_bits);
457 err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
461 dev_dbg(dev, "failed to update trickle charger\n");
464 static inline void rv3029_trickle_config(struct udevice *dev)
469 static int rv3029_probe(struct udevice *dev)
471 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
472 DM_I2C_CHIP_WR_ADDRESS);
474 rv3029_trickle_config(dev);
478 static const struct rtc_ops rv3029_rtc_ops = {
479 .get = rv3029_rtc_get,
480 .set = rv3029_rtc_set,
481 .read8 = rv3029_rtc_read8,
482 .write8 = rv3029_rtc_write8,
483 .reset = rv3029_rtc_reset,
486 static const struct udevice_id rv3029_rtc_ids[] = {
487 { .compatible = "mc,rv3029" },
488 { .compatible = "mc,rv3029c2" },
492 U_BOOT_DRIVER(rtc_rv3029) = {
493 .name = "rtc-rv3029",
495 .probe = rv3029_probe,
496 .of_match = rv3029_rtc_ids,
497 .ops = &rv3029_rtc_ops,