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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
- *
- * Based on a the Linux rtc-rv3029c2.c driver written by:
- * Gregory Hermant <gregory.hermant@calao-systems.com>
- * Michael Buesch <m@bues.ch>
- */
- #include <common.h>
- #include <command.h>
- #include <dm.h>
- #include <eeprom.h>
- #include <i2c.h>
- #include <log.h>
- #include <rtc.h>
- #include <dm/device_compat.h>
- #include <linux/bitops.h>
- #include <linux/delay.h>
- #define RTC_RV3029_PAGE_LEN 7
- /* control section */
- #define RV3029_ONOFF_CTRL 0x00
- #define RV3029_ONOFF_CTRL_WE BIT(0)
- #define RV3029_ONOFF_CTRL_TE BIT(1)
- #define RV3029_ONOFF_CTRL_TAR BIT(2)
- #define RV3029_ONOFF_CTRL_EERE BIT(3)
- #define RV3029_ONOFF_CTRL_SRON BIT(4)
- #define RV3029_ONOFF_CTRL_TD0 BIT(5)
- #define RV3029_ONOFF_CTRL_TD1 BIT(6)
- #define RV3029_ONOFF_CTRL_CLKINT BIT(7)
- #define RV3029_IRQ_CTRL 0x01
- #define RV3029_IRQ_CTRL_AIE BIT(0)
- #define RV3029_IRQ_CTRL_TIE BIT(1)
- #define RV3029_IRQ_CTRL_V1IE BIT(2)
- #define RV3029_IRQ_CTRL_V2IE BIT(3)
- #define RV3029_IRQ_CTRL_SRIE BIT(4)
- #define RV3029_IRQ_FLAGS 0x02
- #define RV3029_IRQ_FLAGS_AF BIT(0)
- #define RV3029_IRQ_FLAGS_TF BIT(1)
- #define RV3029_IRQ_FLAGS_V1IF BIT(2)
- #define RV3029_IRQ_FLAGS_V2IF BIT(3)
- #define RV3029_IRQ_FLAGS_SRF BIT(4)
- #define RV3029_STATUS 0x03
- #define RV3029_STATUS_VLOW1 BIT(2)
- #define RV3029_STATUS_VLOW2 BIT(3)
- #define RV3029_STATUS_SR BIT(4)
- #define RV3029_STATUS_PON BIT(5)
- #define RV3029_STATUS_EEBUSY BIT(7)
- #define RV3029_RST_CTRL 0x04
- #define RV3029_RST_CTRL_SYSR BIT(4)
- #define RV3029_CONTROL_SECTION_LEN 0x05
- /* watch section */
- #define RV3029_W_SEC 0x08
- #define RV3029_W_MINUTES 0x09
- #define RV3029_W_HOURS 0x0A
- #define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */
- #define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */
- #define RV3029_W_DATE 0x0B
- #define RV3029_W_DAYS 0x0C
- #define RV3029_W_MONTHS 0x0D
- #define RV3029_W_YEARS 0x0E
- /* eeprom control section */
- #define RV3029_CONTROL_E2P_EECTRL 0x30
- #define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */
- #define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */
- #define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */
- #define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */
- #define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\
- RV3029_TRICKLE_5K |\
- RV3029_TRICKLE_20K |\
- RV3029_TRICKLE_80K)
- #define RV3029_TRICKLE_SHIFT 4
- static int rv3029_rtc_get(struct udevice *dev, struct rtc_time *tm)
- {
- u8 regs[RTC_RV3029_PAGE_LEN];
- int ret;
- ret = dm_i2c_read(dev, RV3029_W_SEC, regs, sizeof(regs));
- if (ret < 0) {
- printf("%s: error reading RTC: %x\n", __func__, ret);
- return -EIO;
- }
- tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
- tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
- /* HR field has a more complex interpretation */
- {
- const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
- if (_hr & RV3029_REG_HR_12_24) {
- /* 12h format */
- tm->tm_hour = bcd2bin(_hr & 0x1f);
- if (_hr & RV3029_REG_HR_PM) /* PM flag set */
- tm->tm_hour += 12;
- } else {
- /* 24h format */
- tm->tm_hour = bcd2bin(_hr & 0x3f);
- }
- }
- tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
- tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
- /* RTC supports only years > 1999 */
- tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 2000;
- tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
- tm->tm_yday = 0;
- tm->tm_isdst = 0;
- debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
- __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
- tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
- return 0;
- }
- static int rv3029_rtc_set(struct udevice *dev, const struct rtc_time *tm)
- {
- u8 regs[RTC_RV3029_PAGE_LEN];
- debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n",
- __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
- tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
- if (tm->tm_year < 2000) {
- printf("%s: year %d (before 2000) not supported\n",
- __func__, tm->tm_year);
- return -EINVAL;
- }
- regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
- regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
- regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
- regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
- regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
- regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
- regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 2000);
- return dm_i2c_write(dev, RV3029_W_SEC, regs, sizeof(regs));
- }
- static int rv3029_rtc_reset(struct udevice *dev)
- {
- u8 ctrl = RV3029_RST_CTRL_SYSR;
- unsigned long start;
- const unsigned long timeout_ms = 10000;
- int ret;
- /* trigger the system-reset */
- ret = dm_i2c_write(dev, RV3029_RST_CTRL, &ctrl, 1);
- if (ret < 0)
- return -EIO;
- /* wait for the system-reset to complete */
- start = get_timer(0);
- do {
- if (get_timer(start) > timeout_ms)
- return -ETIMEDOUT;
- ret = dm_i2c_read(dev, RV3029_RST_CTRL, &ctrl, 1);
- if (ret < 0)
- return -EIO;
- } while (ctrl & RV3029_RST_CTRL_SYSR);
- return 0;
- }
- static int rv3029_rtc_read8(struct udevice *dev, unsigned int reg)
- {
- u8 data;
- int ret;
- ret = dm_i2c_read(dev, reg, &data, sizeof(data));
- return ret < 0 ? ret : data;
- }
- static int rv3029_rtc_write8(struct udevice *dev, unsigned int reg, int val)
- {
- u8 data = val;
- return dm_i2c_write(dev, reg, &data, 1);
- }
- #if defined(OF_CONTROL)
- static int rv3029_get_sr(struct udevice *dev, u8 *buf)
- {
- int ret = dm_i2c_read(dev, RV3029_STATUS, buf, 1);
- if (ret < 0)
- return -EIO;
- dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
- return 0;
- }
- static int rv3029_set_sr(struct udevice *dev, u8 val)
- {
- int ret;
- ret = dm_i2c_read(dev, RV3029_STATUS, &val, 1);
- if (ret < 0)
- return -EIO;
- dev_dbg(dev, "status = 0x%.2x (%d)\n", val, val);
- return 0;
- }
- static int rv3029_eeprom_busywait(struct udevice *dev)
- {
- int i, ret;
- u8 sr;
- for (i = 100; i > 0; i--) {
- ret = rv3029_get_sr(dev, &sr);
- if (ret < 0)
- break;
- if (!(sr & RV3029_STATUS_EEBUSY))
- break;
- udelay(10000);
- }
- if (i <= 0) {
- dev_err(dev, "EEPROM busy wait timeout.\n");
- return -ETIMEDOUT;
- }
- return ret;
- }
- static int rv3029_update_bits(struct udevice *dev, u8 reg, u8 mask, u8 set)
- {
- u8 buf;
- int ret;
- ret = dm_i2c_read(dev, reg, &buf, 1);
- if (ret < 0)
- return ret;
- if ((buf & mask) == (set && mask))
- return 0;
- buf = (buf & ~mask) | (set & mask);
- ret = dm_i2c_read(dev, reg, &buf, 1);
- if (ret < 0)
- return ret;
- return 0;
- }
- static int rv3029_eeprom_exit(struct udevice *dev)
- {
- /* Re-enable eeprom refresh */
- return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
- RV3029_ONOFF_CTRL_EERE,
- RV3029_ONOFF_CTRL_EERE);
- }
- static int rv3029_eeprom_enter(struct udevice *dev)
- {
- int ret;
- u8 sr;
- /* Check whether we are in the allowed voltage range. */
- ret = rv3029_get_sr(dev, &sr);
- if (ret < 0)
- return ret;
- if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
- /* We clear the bits and retry once just in case
- * we had a brown out in early startup.
- */
- sr &= ~RV3029_STATUS_VLOW1;
- sr &= ~RV3029_STATUS_VLOW2;
- ret = rv3029_set_sr(dev, sr);
- if (ret < 0)
- return ret;
- udelay(10000);
- ret = rv3029_get_sr(dev, &sr);
- if (ret < 0)
- return ret;
- if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
- dev_err(dev, "Supply voltage is too low to safely access the EEPROM.\n");
- return -ENODEV;
- }
- }
- /* Disable eeprom refresh. */
- ret = rv3029_update_bits(dev,
- RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, 0);
- if (ret < 0)
- return ret;
- /* Wait for any previous eeprom accesses to finish. */
- ret = rv3029_eeprom_busywait(dev);
- if (ret < 0)
- rv3029_eeprom_exit(dev);
- return ret;
- }
- static int rv3029_eeprom_read(struct udevice *dev, u8 reg,
- u8 buf[], size_t len)
- {
- int ret, err;
- err = rv3029_eeprom_enter(dev);
- if (err < 0)
- return err;
- ret = dm_i2c_read(dev, reg, buf, len);
- err = rv3029_eeprom_exit(dev);
- if (err < 0)
- return err;
- return ret;
- }
- static int rv3029_eeprom_write(struct udevice *dev, u8 reg,
- u8 const buf[], size_t len)
- {
- int ret;
- size_t i;
- u8 tmp;
- ret = rv3029_eeprom_enter(dev);
- if (ret < 0)
- return ret;
- for (i = 0; i < len; i++, reg++) {
- ret = dm_i2c_read(dev, reg, &tmp, 1);
- if (ret < 0)
- break;
- if (tmp != buf[i]) {
- ret = dm_i2c_write(dev, reg, &buf[i], 1);
- if (ret < 0)
- break;
- }
- ret = rv3029_eeprom_busywait(dev);
- if (ret < 0)
- break;
- }
- ret = rv3029_eeprom_exit(dev);
- if (ret < 0)
- return ret;
- return 0;
- }
- static int rv3029_eeprom_update_bits(struct udevice *dev,
- u8 reg, u8 mask, u8 set)
- {
- u8 buf;
- int ret;
- ret = rv3029_eeprom_read(dev, reg, &buf, 1);
- if (ret < 0)
- return ret;
- /*
- * If the EEPROM already reads the correct bitpattern, we don't need
- * to update it.
- */
- if ((buf & mask) == (set & mask))
- return 0;
- buf = (buf & ~mask) | (set & mask);
- ret = rv3029_eeprom_write(dev, reg, &buf, 1);
- if (ret < 0)
- return ret;
- return 0;
- }
- static void rv3029_trickle_config(struct udevice *dev)
- {
- static const struct rv3029_trickle_tab_elem {
- u32 r; /* resistance in ohms */
- u8 conf; /* trickle config bits */
- } rv3029_trickle_tab[] = {
- {
- .r = 1076,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
- RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
- }, {
- .r = 1091,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
- RV3029_TRICKLE_20K,
- }, {
- .r = 1137,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
- RV3029_TRICKLE_80K,
- }, {
- .r = 1154,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
- }, {
- .r = 1371,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
- RV3029_TRICKLE_80K,
- }, {
- .r = 1395,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
- }, {
- .r = 1472,
- .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
- }, {
- .r = 1500,
- .conf = RV3029_TRICKLE_1K,
- }, {
- .r = 3810,
- .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
- RV3029_TRICKLE_80K,
- }, {
- .r = 4000,
- .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
- }, {
- .r = 4706,
- .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
- }, {
- .r = 5000,
- .conf = RV3029_TRICKLE_5K,
- }, {
- .r = 16000,
- .conf = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
- }, {
- .r = 20000,
- .conf = RV3029_TRICKLE_20K,
- }, {
- .r = 80000,
- .conf = RV3029_TRICKLE_80K,
- },
- };
- int err;
- u32 ohms;
- u8 trickle_set_bits = 0;
- /* Configure the trickle charger. */
- err = dev_read_u32(dev, "trickle-resistor-ohms", &ohms);
- if (!err) {
- /* Find trickle-charger config */
- for (int i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++)
- if (rv3029_trickle_tab[i].r >= ohms) {
- dev_dbg(dev, "trickle charger at %d ohms\n",
- rv3029_trickle_tab[i].r);
- trickle_set_bits = rv3029_trickle_tab[i].conf;
- break;
- }
- }
- dev_dbg(dev, "trickle charger config 0x%x\n", trickle_set_bits);
- err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
- RV3029_TRICKLE_MASK,
- trickle_set_bits);
- if (err < 0)
- dev_dbg(dev, "failed to update trickle charger\n");
- }
- #else
- static inline void rv3029_trickle_config(struct udevice *dev)
- {
- }
- #endif
- static int rv3029_probe(struct udevice *dev)
- {
- i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
- DM_I2C_CHIP_WR_ADDRESS);
- rv3029_trickle_config(dev);
- return 0;
- }
- static const struct rtc_ops rv3029_rtc_ops = {
- .get = rv3029_rtc_get,
- .set = rv3029_rtc_set,
- .read8 = rv3029_rtc_read8,
- .write8 = rv3029_rtc_write8,
- .reset = rv3029_rtc_reset,
- };
- static const struct udevice_id rv3029_rtc_ids[] = {
- { .compatible = "mc,rv3029" },
- { .compatible = "mc,rv3029c2" },
- { }
- };
- U_BOOT_DRIVER(rtc_rv3029) = {
- .name = "rtc-rv3029",
- .id = UCLASS_RTC,
- .probe = rv3029_probe,
- .of_match = rv3029_rtc_ids,
- .ops = &rv3029_rtc_ops,
- };
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