/* $NetBSD: gttwsi_core.c,v 1.18 2021/08/07 16:19:11 thorpej Exp $ */ /* * Copyright (c) 2008 Eiji Kawauchi. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed for the NetBSD Project by * Eiji Kawauchi. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Copyright (c) 2005 Brocade Communcations, inc. * All rights reserved. * * Written by Matt Thomas for Brocade Communcations, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of Brocade Communications, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BROCADE COMMUNICATIONS, INC. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL EITHER BROCADE COMMUNICATIONS, INC. BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. */ //#define TWSI_DEBUG /* * Marvell Two-Wire Serial Interface (aka I2C) master driver */ #include __KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.18 2021/08/07 16:19:11 thorpej Exp $"); #include "locators.h" #include #include #include #include #include #include #include #include #include #include #include static int gttwsi_send_start(void *v, int flags); static int gttwsi_send_stop(void *v, int flags); static int gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags); static int gttwsi_read_byte(void *v, uint8_t *valp, int flags); static int gttwsi_write_byte(void *v, uint8_t val, int flags); static int gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t, uint32_t, int, const char *); uint32_t gttwsi_read_4(struct gttwsi_softc *sc, uint32_t reg) { const uint32_t val = bus_space_read_4(sc->sc_bust, sc->sc_bush, sc->sc_regmap[reg]); #ifdef TWSI_DEBUG printf("I2C:R:[%" PRIu32 "]%02" PRIxBUSSIZE ":%02" PRIx32 "\n", reg, sc->sc_regmap[reg], val); #else DELAY(TWSI_READ_DELAY); #endif return val; } void gttwsi_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val) { bus_space_write_4(sc->sc_bust, sc->sc_bush, sc->sc_regmap[reg], val); #ifdef TWSI_DEBUG printf("I2C:W:[%" PRIu32 "]%02" PRIxBUSSIZE ":%02" PRIx32 "\n", reg, sc->sc_regmap[reg], val); #else DELAY(TWSI_WRITE_DELAY); #endif } /* ARGSUSED */ void gttwsi_attach_subr(device_t self, bus_space_tag_t iot, bus_space_handle_t ioh, const bus_size_t *regmap) { struct gttwsi_softc * const sc = device_private(self); prop_dictionary_t cfg = device_properties(self); aprint_naive("\n"); aprint_normal(": Marvell TWSI controller\n"); sc->sc_dev = self; sc->sc_bust = iot; sc->sc_bush = ioh; sc->sc_regmap = regmap; mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_BIO); cv_init(&sc->sc_cv, device_xname(self)); prop_dictionary_get_bool(cfg, "iflg-rwc", &sc->sc_iflg_rwc); sc->sc_started = false; iic_tag_init(&sc->sc_i2c); sc->sc_i2c.ic_cookie = sc; sc->sc_i2c.ic_send_start = gttwsi_send_start; sc->sc_i2c.ic_send_stop = gttwsi_send_stop; sc->sc_i2c.ic_initiate_xfer = gttwsi_initiate_xfer; sc->sc_i2c.ic_read_byte = gttwsi_read_byte; sc->sc_i2c.ic_write_byte = gttwsi_write_byte; /* * Put the controller into Soft Reset. */ /* reset */ gttwsi_write_4(sc, TWSI_SOFTRESET, SOFTRESET_VAL); } void gttwsi_config_children(device_t self) { struct gttwsi_softc * const sc = device_private(self); struct i2cbus_attach_args iba; memset(&iba, 0, sizeof(iba)); iba.iba_tag = &sc->sc_i2c; config_found(sc->sc_dev, &iba, iicbus_print, CFARGS(.iattr = "i2cbus")); } int gttwsi_intr(void *arg) { struct gttwsi_softc *sc = arg; uint32_t val; mutex_enter(&sc->sc_mtx); val = gttwsi_read_4(sc, TWSI_CONTROL); if (val & CONTROL_IFLG) { gttwsi_write_4(sc, TWSI_CONTROL, val & ~CONTROL_INTEN); cv_broadcast(&sc->sc_cv); mutex_exit(&sc->sc_mtx); return 1; /* handled */ } mutex_exit(&sc->sc_mtx); return 0; } static int gttwsi_send_start(void *v, int flags) { struct gttwsi_softc *sc = v; int expect; if (sc->sc_started) expect = STAT_RSCT; else expect = STAT_SCT; sc->sc_started = true; return gttwsi_wait(sc, CONTROL_START, expect, 0, flags, "send-start"); } static int gttwsi_send_stop(void *v, int flags) { struct gttwsi_softc *sc = v; int retry = TWSI_RETRY_COUNT; uint32_t control, status; sc->sc_started = false; /* Interrupt is not generated for STAT_NRS. */ control = CONTROL_STOP | CONTROL_TWSIEN; if (sc->sc_iflg_rwc) control |= CONTROL_IFLG; gttwsi_write_4(sc, TWSI_CONTROL, control); while (retry > 0) { if ((status = gttwsi_read_4(sc, TWSI_STATUS)) == STAT_NRS) return 0; retry--; DELAY(TWSI_STAT_DELAY); } aprint_error_dev(sc->sc_dev, "send STOP failed, status=0x%02x\n", status); return EWOULDBLOCK; } static int gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags) { struct gttwsi_softc *sc = v; uint32_t data, expect, alt; int error, read; error = gttwsi_send_start(v, flags); if (error) return error; read = (flags & I2C_F_READ) != 0; if (read) { expect = STAT_ARBT_AR; alt = STAT_ARBT_ANR; } else { expect = STAT_AWBT_AR; alt = STAT_AWBT_ANR; } /* * First byte contains whether this xfer is a read or write. */ data = read; if (addr > 0x7f) { /* * If this is a 10bit request, the first address byte is * 0b11110. */ data |= 0xf0 | ((addr & 0x300) >> 7); gttwsi_write_4(sc, TWSI_DATA, data); error = gttwsi_wait(sc, 0, expect, alt, flags, "send-addr-10"); if (error) return error; /* * The first address byte has been sent, now to send * the second one. */ if (read) { expect = STAT_SARBT_AR; alt = STAT_SARBT_ANR; } else { expect = STAT_SAWBT_AR; alt = STAT_SAWBT_ANR; } data = (uint8_t)addr; } else data |= (addr << 1); gttwsi_write_4(sc, TWSI_DATA, data); return gttwsi_wait(sc, 0, expect, alt, flags, "send-addr"); } static int gttwsi_read_byte(void *v, uint8_t *valp, int flags) { struct gttwsi_softc *sc = v; int error; if (flags & I2C_F_LAST) { error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, 0, flags, "read-last-byte"); } else { error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, 0, flags, "read-byte"); } if (!error) *valp = gttwsi_read_4(sc, TWSI_DATA); if ((flags & (I2C_F_LAST | I2C_F_STOP)) == (I2C_F_LAST | I2C_F_STOP)) error = gttwsi_send_stop(sc, flags); return error; } static int gttwsi_write_byte(void *v, uint8_t val, int flags) { struct gttwsi_softc *sc = v; int error; gttwsi_write_4(sc, TWSI_DATA, val); error = gttwsi_wait(sc, 0, STAT_MTDB_AR, 0, flags, "write-byte"); if (flags & I2C_F_STOP) gttwsi_send_stop(sc, flags); return error; } static int gttwsi_wait(struct gttwsi_softc *sc, uint32_t control, uint32_t expect, uint32_t alt, int flags, const char *what) { uint32_t status; int timo, error = 0; /* * XXX Interrupt-driven mode seems to be horribly broken, * XXX at least on AllWinner implementations. Force polled * XXX mode for now. */ flags |= I2C_F_POLL; DELAY(5); if (!(flags & I2C_F_POLL)) control |= CONTROL_INTEN; if (sc->sc_iflg_rwc) control |= CONTROL_IFLG; mutex_enter(&sc->sc_mtx); gttwsi_write_4(sc, TWSI_CONTROL, control | CONTROL_TWSIEN); timo = 0; for (;;) { control = gttwsi_read_4(sc, TWSI_CONTROL); if (control & CONTROL_IFLG) break; if (!(flags & I2C_F_POLL)) { error = cv_timedwait(&sc->sc_cv, &sc->sc_mtx, hz); if (error) { break; } } else { DELAY(TWSI_RETRY_DELAY); if (timo++ > 1000000) /* 1sec */ break; } } if ((control & CONTROL_IFLG) == 0) { /* * error is set by the cv_timedwait() call above in the * non-polled case. */ if (flags & I2C_F_POLL) { error = EWOULDBLOCK; } else { KASSERT(error != 0); } aprint_error_dev(sc->sc_dev, "gttwsi_wait(): %s timeout%s, control=0x%x, error=%d\n", what, (flags & I2C_F_POLL) ? " (polled)" : "", control, error); goto end; } status = gttwsi_read_4(sc, TWSI_STATUS); if (status != expect) { /* * In the case of probing for a device, we are expecting * 2 different status codes: the ACK case (device exists), * or the NACK case (device does not exist). We don't * need to report an error in the later case. */ if (alt != 0 && status != alt) aprint_error_dev(sc->sc_dev, "unexpected status 0x%x: expect 0x%x\n", status, expect); error = EIO; } end: mutex_exit(&sc->sc_mtx); return error; }