/* $OpenBSD: mcp794xx.c,v 1.3 2022/10/15 18:22:53 kettenis Exp $ */ /* * Copyright (c) 2018 Mark Kettenis * Copyright (c) 2018 Patrick Wildt * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #define MCP794XX_SC 0x00 #define MCP794XX_SC_ST (1 << 7) #define MCP794XX_MN 0x01 #define MCP794XX_HR 0x02 #define MCP794XX_HR_PM (1 << 5) #define MCP794XX_HR_12H (1 << 6) #define MCP794XX_DW 0x03 #define MCP794XX_DW_VBATEN (1 << 3) #define MCP794XX_DW_PWRFAIL (1 << 4) #define MCP794XX_DW_OSCRUN (1 << 5) #define MCP794XX_DT 0x04 #define MCP794XX_MO 0x05 #define MCP794XX_YR 0x06 #define MCP794XX_CR 0x07 #define MCP794XX_CR_EXTOSC (1 << 3) #define MCP794XX_NRTC_REGS 7 struct mcprtc_softc { struct device sc_dev; i2c_tag_t sc_tag; i2c_addr_t sc_addr; int sc_extosc; struct todr_chip_handle sc_todr; }; int mcprtc_match(struct device *, void *, void *); void mcprtc_attach(struct device *, struct device *, void *); const struct cfattach mcprtc_ca = { sizeof(struct mcprtc_softc), mcprtc_match, mcprtc_attach }; struct cfdriver mcprtc_cd = { NULL, "mcprtc", DV_DULL }; uint8_t mcprtc_reg_read(struct mcprtc_softc *, int); void mcprtc_reg_write(struct mcprtc_softc *, int, uint8_t); int mcprtc_clock_read(struct mcprtc_softc *, struct clock_ymdhms *); int mcprtc_clock_write(struct mcprtc_softc *, struct clock_ymdhms *); int mcprtc_gettime(struct todr_chip_handle *, struct timeval *); int mcprtc_settime(struct todr_chip_handle *, struct timeval *); int mcprtc_match(struct device *parent, void *match, void *aux) { struct i2c_attach_args *ia = aux; if (strcmp(ia->ia_name, "microchip,mcp7940x") == 0 || strcmp(ia->ia_name, "microchip,mcp7941x") == 0) return 1; return 0; } void mcprtc_attach(struct device *parent, struct device *self, void *aux) { struct mcprtc_softc *sc = (struct mcprtc_softc *)self; struct i2c_attach_args *ia = aux; sc->sc_tag = ia->ia_tag; sc->sc_addr = ia->ia_addr; sc->sc_todr.cookie = sc; sc->sc_todr.todr_gettime = mcprtc_gettime; sc->sc_todr.todr_settime = mcprtc_settime; sc->sc_todr.todr_quality = 1000; todr_attach(&sc->sc_todr); printf("\n"); } int mcprtc_gettime(struct todr_chip_handle *handle, struct timeval *tv) { struct mcprtc_softc *sc = handle->cookie; struct clock_ymdhms dt; int error; error = mcprtc_clock_read(sc, &dt); if (error) return error; if (dt.dt_sec > 59 || dt.dt_min > 59 || dt.dt_hour > 23 || dt.dt_day > 31 || dt.dt_day == 0 || dt.dt_mon > 12 || dt.dt_mon == 0 || dt.dt_year < POSIX_BASE_YEAR) return EINVAL; tv->tv_sec = clock_ymdhms_to_secs(&dt); tv->tv_usec = 0; return 0; } int mcprtc_settime(struct todr_chip_handle *handle, struct timeval *tv) { struct mcprtc_softc *sc = handle->cookie; struct clock_ymdhms dt; clock_secs_to_ymdhms(tv->tv_sec, &dt); return mcprtc_clock_write(sc, &dt); } uint8_t mcprtc_reg_read(struct mcprtc_softc *sc, int reg) { uint8_t cmd = reg; uint8_t val; int error; iic_acquire_bus(sc->sc_tag, I2C_F_POLL); error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL); iic_release_bus(sc->sc_tag, I2C_F_POLL); if (error) { printf("%s: can't read register 0x%02x\n", sc->sc_dev.dv_xname, reg); val = 0xff; } return val; } void mcprtc_reg_write(struct mcprtc_softc *sc, int reg, uint8_t val) { uint8_t cmd = reg; int error; iic_acquire_bus(sc->sc_tag, I2C_F_POLL); error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL); iic_release_bus(sc->sc_tag, I2C_F_POLL); if (error) { printf("%s: can't write register 0x%02x\n", sc->sc_dev.dv_xname, reg); } } int mcprtc_clock_read(struct mcprtc_softc *sc, struct clock_ymdhms *dt) { uint8_t regs[MCP794XX_NRTC_REGS]; uint8_t cmd = MCP794XX_SC; int error; /* Don't trust the RTC if the oscillator is not running. */ if (!(mcprtc_reg_read(sc, MCP794XX_DW) & MCP794XX_DW_OSCRUN)) return EIO; iic_acquire_bus(sc->sc_tag, I2C_F_POLL); error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &cmd, sizeof(cmd), regs, MCP794XX_NRTC_REGS, I2C_F_POLL); iic_release_bus(sc->sc_tag, I2C_F_POLL); if (error) { printf("%s: can't read RTC\n", sc->sc_dev.dv_xname); return error; } /* * Convert the MCP794XX's register values into something useable. */ dt->dt_sec = FROMBCD(regs[0] & 0x7f); dt->dt_min = FROMBCD(regs[1] & 0x7f); dt->dt_hour = FROMBCD(regs[2] & 0x1f); if ((regs[2] & MCP794XX_HR_12H) && (regs[2] & MCP794XX_HR_PM)) dt->dt_hour += 12; dt->dt_wday = FROMBCD(regs[3] & 0x7); dt->dt_day = FROMBCD(regs[4] & 0x3f); dt->dt_mon = FROMBCD(regs[5] & 0x1f); dt->dt_year = FROMBCD(regs[6]) + 2000; return 0; } int mcprtc_clock_write(struct mcprtc_softc *sc, struct clock_ymdhms *dt) { uint8_t regs[MCP794XX_NRTC_REGS]; uint8_t cmd = MCP794XX_SC; uint8_t oscoff, oscbit; uint8_t reg; int error, i; /* * Convert our time representation into something the MCP794XX * can understand. */ regs[0] = TOBCD(dt->dt_sec); regs[1] = TOBCD(dt->dt_min); regs[2] = TOBCD(dt->dt_hour); regs[3] = TOBCD(dt->dt_wday) | MCP794XX_DW_VBATEN; regs[4] = TOBCD(dt->dt_day); regs[5] = TOBCD(dt->dt_mon); regs[6] = TOBCD(dt->dt_year - 2000); /* Stop RTC. */ if (sc->sc_extosc) { oscoff = MCP794XX_CR; oscbit = MCP794XX_CR_EXTOSC; } else { oscoff = MCP794XX_SC; oscbit = MCP794XX_SC_ST; } /* Stop RTC such that we can write to it. */ reg = mcprtc_reg_read(sc, oscoff); reg &= ~oscbit; mcprtc_reg_write(sc, oscoff, reg); for (i = 0; i < 10; i++) { reg = mcprtc_reg_read(sc, MCP794XX_DW); if ((reg & MCP794XX_DW_OSCRUN) == 0) break; delay(10); } if (i == 10) { error = EIO; goto fail; } iic_acquire_bus(sc->sc_tag, I2C_F_POLL); error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, &cmd, sizeof(cmd), regs, MCP794XX_NRTC_REGS, I2C_F_POLL); iic_release_bus(sc->sc_tag, I2C_F_POLL); /* Restart RTC. */ reg = mcprtc_reg_read(sc, oscoff); reg |= oscbit; mcprtc_reg_write(sc, oscoff, reg); fail: if (error) { printf("%s: can't write RTC\n", sc->sc_dev.dv_xname); return error; } return 0; }