--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * A driver for the I2C members of the Abracon AB x8xx RTC family,
+ * and compatible: AB 1805 and AB 0805
+ *
+ * Copyright 2014-2015 Macq S.A.
+ * Copyright 2020 Linaro
+ *
+ * Author: Philippe De Muyter <phdm@macqel.be>
+ * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
+ * Author: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <rtc.h>
+#include <log.h>
+
+#define ABX8XX_REG_HTH 0x00
+#define ABX8XX_REG_SC 0x01
+#define ABX8XX_REG_MN 0x02
+#define ABX8XX_REG_HR 0x03
+#define ABX8XX_REG_DA 0x04
+#define ABX8XX_REG_MO 0x05
+#define ABX8XX_REG_YR 0x06
+#define ABX8XX_REG_WD 0x07
+
+#define ABX8XX_REG_AHTH 0x08
+#define ABX8XX_REG_ASC 0x09
+#define ABX8XX_REG_AMN 0x0a
+#define ABX8XX_REG_AHR 0x0b
+#define ABX8XX_REG_ADA 0x0c
+#define ABX8XX_REG_AMO 0x0d
+#define ABX8XX_REG_AWD 0x0e
+
+#define ABX8XX_REG_STATUS 0x0f
+#define ABX8XX_STATUS_AF BIT(2)
+#define ABX8XX_STATUS_BLF BIT(4)
+#define ABX8XX_STATUS_WDT BIT(6)
+
+#define ABX8XX_REG_CTRL1 0x10
+#define ABX8XX_CTRL_WRITE BIT(0)
+#define ABX8XX_CTRL_ARST BIT(2)
+#define ABX8XX_CTRL_12_24 BIT(6)
+
+#define ABX8XX_REG_CTRL2 0x11
+#define ABX8XX_CTRL2_RSVD BIT(5)
+
+#define ABX8XX_REG_IRQ 0x12
+#define ABX8XX_IRQ_AIE BIT(2)
+#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
+
+#define ABX8XX_REG_CD_TIMER_CTL 0x18
+
+#define ABX8XX_REG_OSC 0x1c
+#define ABX8XX_OSC_FOS BIT(3)
+#define ABX8XX_OSC_BOS BIT(4)
+#define ABX8XX_OSC_ACAL_512 BIT(5)
+#define ABX8XX_OSC_ACAL_1024 BIT(6)
+
+#define ABX8XX_OSC_OSEL BIT(7)
+
+#define ABX8XX_REG_OSS 0x1d
+#define ABX8XX_OSS_OF BIT(1)
+#define ABX8XX_OSS_OMODE BIT(4)
+
+#define ABX8XX_REG_WDT 0x1b
+#define ABX8XX_WDT_WDS BIT(7)
+#define ABX8XX_WDT_BMB_MASK 0x7c
+#define ABX8XX_WDT_BMB_SHIFT 2
+#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
+#define ABX8XX_WDT_WRB_MASK 0x03
+#define ABX8XX_WDT_WRB_1HZ 0x02
+
+#define ABX8XX_REG_CFG_KEY 0x1f
+#define ABX8XX_CFG_KEY_OSC 0xa1
+#define ABX8XX_CFG_KEY_MISC 0x9d
+
+#define ABX8XX_REG_ID0 0x28
+
+#define ABX8XX_REG_OUT_CTRL 0x30
+#define ABX8XX_OUT_CTRL_EXDS BIT(4)
+
+#define ABX8XX_REG_TRICKLE 0x20
+#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
+#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
+#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
+
+static u8 trickle_resistors[] = {0, 3, 6, 11};
+
+enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
+ AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
+
+struct abx80x_cap {
+ u16 pn;
+ bool has_tc;
+ bool has_wdog;
+};
+
+static struct abx80x_cap abx80x_caps[] = {
+ [AB0801] = {.pn = 0x0801},
+ [AB0803] = {.pn = 0x0803},
+ [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
+ [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
+ [AB1801] = {.pn = 0x1801},
+ [AB1803] = {.pn = 0x1803},
+ [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
+ [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
+ [RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
+ [ABX80X] = {.pn = 0}
+};
+
+static int abx80x_rtc_read8(struct udevice *dev, unsigned int reg)
+{
+ int ret = 0;
+ u8 buf;
+
+ if (reg > 0xff)
+ return -EINVAL;
+
+ ret = dm_i2c_read(dev, reg, &buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ return buf;
+}
+
+static int abx80x_rtc_write8(struct udevice *dev, unsigned int reg, int val)
+{
+ u8 buf = (u8)val;
+
+ if (reg > 0xff)
+ return -EINVAL;
+
+ return dm_i2c_write(dev, reg, &buf, sizeof(buf));
+}
+
+static int abx80x_is_rc_mode(struct udevice *dev)
+{
+ int flags = 0;
+
+ flags = dm_i2c_reg_read(dev, ABX8XX_REG_OSS);
+ if (flags < 0) {
+ log_err("Failed to read autocalibration attribute\n");
+ return flags;
+ }
+
+ return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
+}
+
+static int abx80x_enable_trickle_charger(struct udevice *dev, u8 trickle_cfg)
+{
+ int err;
+
+ /*
+ * Write the configuration key register to enable access to the Trickle
+ * register
+ */
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_CFG_KEY, ABX8XX_CFG_KEY_MISC);
+ if (err < 0) {
+ log_err("Unable to write configuration key\n");
+ return -EIO;
+ }
+
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_TRICKLE,
+ ABX8XX_TRICKLE_CHARGE_ENABLE | trickle_cfg);
+ if (err < 0) {
+ log_err("Unable to write trickle register\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int abx80x_rtc_read_time(struct udevice *dev, struct rtc_time *tm)
+{
+ unsigned char buf[8];
+ int err, flags, rc_mode = 0;
+
+ /* Read the Oscillator Failure only in XT mode */
+ rc_mode = abx80x_is_rc_mode(dev);
+ if (rc_mode < 0)
+ return rc_mode;
+
+ if (!rc_mode) {
+ flags = dm_i2c_reg_read(dev, ABX8XX_REG_OSS);
+ if (flags < 0) {
+ log_err("Unable to read oscillator status.\n");
+ return flags;
+ }
+
+ if (flags & ABX8XX_OSS_OF)
+ log_debug("Oscillator fail, data is not accurate.\n");
+ }
+
+ err = dm_i2c_read(dev, ABX8XX_REG_HTH,
+ buf, sizeof(buf));
+ if (err < 0) {
+ log_err("Unable to read date\n");
+ return -EIO;
+ }
+
+ tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
+ tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
+ tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
+ tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
+ tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
+ tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F);
+ tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 2000;
+
+ return 0;
+}
+
+static int abx80x_rtc_set_time(struct udevice *dev, const struct rtc_time *tm)
+{
+ unsigned char buf[8];
+ int err, flags;
+
+ if (tm->tm_year < 2000)
+ return -EINVAL;
+
+ buf[ABX8XX_REG_HTH] = 0;
+ buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
+ buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
+ buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
+ buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
+ buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon);
+ buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 2000);
+ buf[ABX8XX_REG_WD] = tm->tm_wday;
+
+ err = dm_i2c_write(dev, ABX8XX_REG_HTH,
+ buf, sizeof(buf));
+ if (err < 0) {
+ log_err("Unable to write to date registers\n");
+ return -EIO;
+ }
+
+ /* Clear the OF bit of Oscillator Status Register */
+ flags = dm_i2c_reg_read(dev, ABX8XX_REG_OSS);
+ if (flags < 0) {
+ log_err("Unable to read oscillator status.\n");
+ return flags;
+ }
+
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_OSS,
+ flags & ~ABX8XX_OSS_OF);
+ if (err < 0) {
+ log_err("Unable to write oscillator status register\n");
+ return err;
+ }
+
+ return 0;
+}
+
+static int abx80x_rtc_set_autocalibration(struct udevice *dev,
+ int autocalibration)
+{
+ int retval, flags = 0;
+
+ if (autocalibration != 0 && autocalibration != 1024 &&
+ autocalibration != 512) {
+ log_err("autocalibration value outside permitted range\n");
+ return -EINVAL;
+ }
+
+ flags = dm_i2c_reg_read(dev, ABX8XX_REG_OSC);
+ if (flags < 0)
+ return flags;
+
+ if (autocalibration == 0) {
+ flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
+ } else if (autocalibration == 1024) {
+ /* 1024 autocalibration is 0x10 */
+ flags |= ABX8XX_OSC_ACAL_1024;
+ flags &= ~(ABX8XX_OSC_ACAL_512);
+ } else {
+ /* 512 autocalibration is 0x11 */
+ flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
+ }
+
+ /* Unlock write access to Oscillator Control Register */
+ retval = dm_i2c_reg_write(dev, ABX8XX_REG_CFG_KEY,
+ ABX8XX_CFG_KEY_OSC);
+ if (retval < 0) {
+ log_err("Failed to write CONFIG_KEY register\n");
+ return retval;
+ }
+
+ retval = dm_i2c_reg_write(dev, ABX8XX_REG_OSC, flags);
+
+ return retval;
+}
+
+static int abx80x_rtc_get_autocalibration(struct udevice *dev)
+{
+ int flags = 0, autocalibration;
+
+ flags = dm_i2c_reg_read(dev, ABX8XX_REG_OSC);
+ if (flags < 0)
+ return flags;
+
+ if (flags & ABX8XX_OSC_ACAL_512)
+ autocalibration = 512;
+ else if (flags & ABX8XX_OSC_ACAL_1024)
+ autocalibration = 1024;
+ else
+ autocalibration = 0;
+
+ return autocalibration;
+}
+
+static struct rtc_time default_tm = { 0, 0, 0, 1, 1, 2000, 6, 0, 0 };
+
+static int abx80x_rtc_reset(struct udevice *dev)
+{
+ int ret = 0;
+
+ int autocalib = abx80x_rtc_get_autocalibration(dev);
+
+ if (autocalib != 0)
+ abx80x_rtc_set_autocalibration(dev, 0);
+
+ ret = abx80x_rtc_set_time(dev, &default_tm);
+ if (ret != 0) {
+ log_err("cannot set time to default_tm. error %d\n", ret);
+ return ret;
+ }
+
+ return ret;
+}
+
+static const struct rtc_ops abx80x_rtc_ops = {
+ .get = abx80x_rtc_read_time,
+ .set = abx80x_rtc_set_time,
+ .reset = abx80x_rtc_reset,
+ .read8 = abx80x_rtc_read8,
+ .write8 = abx80x_rtc_write8
+};
+
+static int abx80x_dt_trickle_cfg(struct udevice *dev)
+{
+ const char *diode;
+ int trickle_cfg = 0;
+ int i, ret = 0;
+ u32 tmp;
+
+ diode = ofnode_read_string(dev_ofnode(dev), "abracon,tc-diode");
+ if (!diode)
+ return ret;
+
+ if (!strcmp(diode, "standard")) {
+ trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
+ } else if (!strcmp(diode, "schottky")) {
+ trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
+ } else {
+ log_err("Invalid tc-diode value: %s\n", diode);
+ return -EINVAL;
+ }
+
+ ret = ofnode_read_u32(dev_ofnode(dev), "abracon,tc-resistor", &tmp);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < sizeof(trickle_resistors); i++)
+ if (trickle_resistors[i] == tmp)
+ break;
+
+ if (i == sizeof(trickle_resistors)) {
+ log_err("Invalid tc-resistor value: %u\n", tmp);
+ return -EINVAL;
+ }
+
+ return (trickle_cfg | i);
+}
+
+static int abx80x_probe(struct udevice *dev)
+{
+ int i, data, err, trickle_cfg = -EINVAL;
+ unsigned char buf[7];
+ unsigned int part = dev->driver_data;
+ unsigned int partnumber;
+ unsigned int majrev, minrev;
+ unsigned int lot;
+ unsigned int wafer;
+ unsigned int uid;
+
+ err = dm_i2c_read(dev, ABX8XX_REG_ID0, buf, sizeof(buf));
+ if (err < 0) {
+ log_err("Unable to read partnumber\n");
+ return -EIO;
+ }
+
+ partnumber = (buf[0] << 8) | buf[1];
+ majrev = buf[2] >> 3;
+ minrev = buf[2] & 0x7;
+ lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
+ uid = ((buf[4] & 0x7f) << 8) | buf[5];
+ wafer = (buf[6] & 0x7c) >> 2;
+ log_debug("model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
+ partnumber, majrev, minrev, lot, wafer, uid);
+
+ data = dm_i2c_reg_read(dev, ABX8XX_REG_CTRL1);
+ if (data < 0) {
+ log_err("Unable to read control register\n");
+ return -EIO;
+ }
+
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_CTRL1,
+ ((data & ~(ABX8XX_CTRL_12_24 |
+ ABX8XX_CTRL_ARST)) |
+ ABX8XX_CTRL_WRITE));
+ if (err < 0) {
+ log_err("Unable to write control register\n");
+ return -EIO;
+ }
+
+ /* Configure RV1805 specifics */
+ if (part == RV1805) {
+ /*
+ * Avoid accidentally entering test mode. This can happen
+ * on the RV1805 in case the reserved bit 5 in control2
+ * register is set. RV-1805-C3 datasheet indicates that
+ * the bit should be cleared in section 11h - Control2.
+ */
+ data = dm_i2c_reg_read(dev, ABX8XX_REG_CTRL2);
+ if (data < 0) {
+ log_err("Unable to read control2 register\n");
+ return -EIO;
+ }
+
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_CTRL2,
+ data & ~ABX8XX_CTRL2_RSVD);
+ if (err < 0) {
+ log_err("Unable to write control2 register\n");
+ return -EIO;
+ }
+
+ /*
+ * Avoid extra power leakage. The RV1805 uses smaller
+ * 10pin package and the EXTI input is not present.
+ * Disable it to avoid leakage.
+ */
+ data = dm_i2c_reg_read(dev, ABX8XX_REG_OUT_CTRL);
+ if (data < 0) {
+ log_err("Unable to read output control register\n");
+ return -EIO;
+ }
+
+ /*
+ * Write the configuration key register to enable access to
+ * the config2 register
+ */
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_CFG_KEY,
+ ABX8XX_CFG_KEY_MISC);
+ if (err < 0) {
+ log_err("Unable to write configuration key\n");
+ return -EIO;
+ }
+
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_OUT_CTRL,
+ data | ABX8XX_OUT_CTRL_EXDS);
+ if (err < 0) {
+ log_err("Unable to write output control register\n");
+ return -EIO;
+ }
+ }
+
+ /* part autodetection */
+ if (part == ABX80X) {
+ for (i = 0; abx80x_caps[i].pn; i++)
+ if (partnumber == abx80x_caps[i].pn)
+ break;
+ if (abx80x_caps[i].pn == 0) {
+ log_err("Unknown part: %04x\n", partnumber);
+ return -EINVAL;
+ }
+ part = i;
+ }
+
+ if (partnumber != abx80x_caps[part].pn) {
+ log_err("partnumber mismatch %04x != %04x\n",
+ partnumber, abx80x_caps[part].pn);
+ return -EINVAL;
+ }
+
+ if (abx80x_caps[part].has_tc)
+ trickle_cfg = abx80x_dt_trickle_cfg(dev);
+
+ if (trickle_cfg > 0) {
+ log_debug("Enabling trickle charger: %02x\n", trickle_cfg);
+ abx80x_enable_trickle_charger(dev, trickle_cfg);
+ }
+
+ err = dm_i2c_reg_write(dev, ABX8XX_REG_CD_TIMER_CTL, BIT(2));
+ if (err)
+ return err;
+
+ return 0;
+}
+
+static const struct udevice_id abx80x_of_match[] = {
+ {
+ .compatible = "abracon,abx80x",
+ .data = ABX80X
+ },
+ {
+ .compatible = "abracon,ab0801",
+ .data = AB0801
+ },
+ {
+ .compatible = "abracon,ab0803",
+ .data = AB0803
+ },
+ {
+ .compatible = "abracon,ab0804",
+ .data = AB0804
+ },
+ {
+ .compatible = "abracon,ab0805",
+ .data = AB0805
+ },
+ {
+ .compatible = "abracon,ab1801",
+ .data = AB1801
+ },
+ {
+ .compatible = "abracon,ab1803",
+ .data = AB1803
+ },
+ {
+ .compatible = "abracon,ab1804",
+ .data = AB1804
+ },
+ {
+ .compatible = "abracon,ab1805",
+ .data = AB1805
+ },
+ {
+ .compatible = "microcrystal,rv1805",
+ .data = RV1805
+ },
+ { }
+};
+
+U_BOOT_DRIVER(abx80x_rtc) = {
+ .name = "rtc-abx80x",
+ .id = UCLASS_RTC,
+ .probe = abx80x_probe,
+ .of_match = abx80x_of_match,
+ .ops = &abx80x_rtc_ops,
+};
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