diff options
Diffstat (limited to 'drivers/rtc/rx8025.c')
| -rw-r--r-- | drivers/rtc/rx8025.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/rtc/rx8025.c b/drivers/rtc/rx8025.c new file mode 100644 index 00000000000..c7895244283 --- /dev/null +++ b/drivers/rtc/rx8025.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * (C) Copyright 2007 + * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com. + */ + +/* + * Epson RX8025 RTC driver. + */ + +#include <command.h> +#include <dm.h> +#include <i2c.h> +#include <rtc.h> + +/*---------------------------------------------------------------------*/ +#undef DEBUG_RTC + +#ifdef DEBUG_RTC +#define DEBUGR(fmt,args...) printf(fmt ,##args) +#else +#define DEBUGR(fmt,args...) +#endif +/*---------------------------------------------------------------------*/ + +enum rx_model { + model_rx_8025, + model_rx_8035, +}; + +/* + * RTC register addresses + */ +#define RTC_SEC_REG_ADDR 0x00 +#define RTC_MIN_REG_ADDR 0x01 +#define RTC_HR_REG_ADDR 0x02 +#define RTC_DAY_REG_ADDR 0x03 +#define RTC_DATE_REG_ADDR 0x04 +#define RTC_MON_REG_ADDR 0x05 +#define RTC_YR_REG_ADDR 0x06 +#define RTC_OFFSET_REG_ADDR 0x07 + +#define RTC_CTL1_REG_ADDR 0x0e +#define RTC_CTL2_REG_ADDR 0x0f + +/* + * Control register 1 bits + */ +#define RTC_CTL1_BIT_2412 0x20 + +/* + * Control register 2 bits + */ +#define RTC_CTL2_BIT_PON 0x10 +#define RTC_CTL2_BIT_VDET 0x40 +#define RTC_CTL2_BIT_XST 0x20 +#define RTC_CTL2_BIT_VDSL 0x80 + +/* + * Note: the RX8025 I2C RTC requires register + * reads and write to consist of a single bus + * cycle. It is not allowed to write the register + * address in a first cycle that is terminated by + * a STOP condition. The chips needs a 'restart' + * sequence (start sequence without a prior stop). + */ + +#define rtc_read(reg) buf[(reg) & 0xf] + +static int rtc_write(struct udevice *dev, uchar reg, uchar val); + +static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2) +{ + int xstp = ctrl2 & RTC_CTL2_BIT_XST; + /* XSTP bit has different polarity on RX-8025 vs RX-8035. + * RX-8025: 0 == oscillator stopped + * RX-8035: 1 == oscillator stopped + */ + + if (model == model_rx_8025) + xstp = !xstp; + + return xstp; +} + +/* + * Get the current time from the RTC + */ +static int rx8025_rtc_get(struct udevice *dev, struct rtc_time *tmp) +{ + int rel = 0; + uchar sec, min, hour, mday, wday, mon, year, ctl2; + uchar buf[16]; + + if (dm_i2c_read(dev, 0, buf, sizeof(buf))) { + printf("Error reading from RTC\n"); + return -EIO; + } + + sec = rtc_read(RTC_SEC_REG_ADDR); + min = rtc_read(RTC_MIN_REG_ADDR); + hour = rtc_read(RTC_HR_REG_ADDR); + wday = rtc_read(RTC_DAY_REG_ADDR); + mday = rtc_read(RTC_DATE_REG_ADDR); + mon = rtc_read(RTC_MON_REG_ADDR); + year = rtc_read(RTC_YR_REG_ADDR); + + DEBUGR("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " + "hr: %02x min: %02x sec: %02x\n", + year, mon, mday, wday, hour, min, sec); + + /* dump status */ + ctl2 = rtc_read(RTC_CTL2_REG_ADDR); + if (ctl2 & RTC_CTL2_BIT_PON) { + printf("RTC: power-on detected\n"); + rel = -1; + } + + if (ctl2 & RTC_CTL2_BIT_VDET) { + printf("RTC: voltage drop detected\n"); + rel = -1; + } + if (rx8025_is_osc_stopped(dev->driver_data, ctl2)) { + printf("RTC: oscillator stop detected\n"); + rel = -1; + } + + tmp->tm_sec = bcd2bin(sec & 0x7F); + tmp->tm_min = bcd2bin(min & 0x7F); + if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412) + tmp->tm_hour = bcd2bin(hour & 0x3F); + else + tmp->tm_hour = bcd2bin(hour & 0x1F) % 12 + + ((hour & 0x20) ? 12 : 0); + + tmp->tm_mday = bcd2bin (mday & 0x3F); + tmp->tm_mon = bcd2bin (mon & 0x1F); + tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); + tmp->tm_wday = bcd2bin (wday & 0x07); + tmp->tm_yday = 0; + tmp->tm_isdst= 0; + + DEBUGR("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", + tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, + tmp->tm_hour, tmp->tm_min, tmp->tm_sec); + + return rel; +} + +/* + * Set the RTC + */ +static int rx8025_rtc_set(struct udevice *dev, const struct rtc_time *tmp) +{ + /* To work around the read/write cycle issue mentioned + * at the top of this file, write all the time registers + * in one I2C transaction + */ + u8 write_op[8]; + + /* 2412 flag must be set before doing a RTC write, + * otherwise the seconds and minute register + * will be cleared when the flag is set + */ + if (rtc_write(dev, RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412)) + return -EIO; + + DEBUGR("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", + tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, + tmp->tm_hour, tmp->tm_min, tmp->tm_sec); + + if (tmp->tm_year < 1970 || tmp->tm_year > 2069) + printf("WARNING: year should be between 1970 and 2069!\n"); + + write_op[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec); + write_op[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min); + write_op[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour); + write_op[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday); + write_op[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday); + write_op[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon); + write_op[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100); + write_op[RTC_OFFSET_REG_ADDR] = 0; + + return dm_i2c_write(dev, 0, &write_op[0], 8); +} + +/* + * Reset the RTC + */ +static int rx8025_rtc_reset(struct udevice *dev) +{ + uchar buf[16]; + uchar ctl2; + + if (dm_i2c_read(dev, 0, buf, sizeof(buf))) { + printf("Error reading from RTC\n"); + return -EIO; + } + + ctl2 = rtc_read(RTC_CTL2_REG_ADDR); + ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET); + + if (dev->driver_data == model_rx_8035) + ctl2 &= ~(RTC_CTL2_BIT_XST); + else + ctl2 |= RTC_CTL2_BIT_XST; + + return rtc_write(dev, RTC_CTL2_REG_ADDR, ctl2); +} + +/* + * Helper functions + */ +static int rtc_write(struct udevice *dev, uchar reg, uchar val) +{ + /* The RX8025/RX8035 uses the top 4 bits of the + * 'offset' byte as the start register address, + * and the bottom 4 bits as a 'transfer' mode setting + * (only applicable for reads) + */ + u8 offset = (reg << 4); + + if (dm_i2c_reg_write(dev, offset, val)) { + printf("Error writing to RTC\n"); + return -EIO; + } + + return 0; +} + +static int rx8025_probe(struct udevice *dev) +{ + uchar buf[16]; + int ret = 0; + + if (i2c_get_chip_offset_len(dev) != 1) + ret = i2c_set_chip_offset_len(dev, 1); + + if (ret) + return ret; + + return dm_i2c_read(dev, 0, buf, sizeof(buf)); +} + +static const struct rtc_ops rx8025_rtc_ops = { + .get = rx8025_rtc_get, + .set = rx8025_rtc_set, + .reset = rx8025_rtc_reset, +}; + +static const struct udevice_id rx8025_rtc_ids[] = { + { .compatible = "epson,rx8025", .data = model_rx_8025 }, + { .compatible = "epson,rx8035", .data = model_rx_8035 }, + { } +}; + +U_BOOT_DRIVER(rx8025_rtc) = { + .name = "rx8025_rtc", + .id = UCLASS_RTC, + .probe = rx8025_probe, + .of_match = rx8025_rtc_ids, + .ops = &rx8025_rtc_ops, +}; |