/* $NetBSD: nslu2_iic.c,v 1.9 2016/02/14 19:54:20 chs Exp $ */ /*- * Copyright (c) 2006 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Steve C. Woodford. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 FOUNDATION OR CONTRIBUTORS * 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. */ #include #include #include #include #include #include #include #include #include #include #include struct slugiic_softc { struct i2c_controller sc_ic; struct i2c_bitbang_ops sc_ibo; kmutex_t sc_lock; uint32_t sc_dirout; }; static int slugiic_acquire_bus(void *arg, int flags) { struct slugiic_softc *sc = arg; if (flags & I2C_F_POLL) return (0); mutex_enter(&sc->sc_lock); return (0); } static void slugiic_release_bus(void *arg, int flags) { struct slugiic_softc *sc = arg; if (flags & I2C_F_POLL) return; mutex_exit(&sc->sc_lock); } static int slugiic_send_start(void *arg, int flags) { struct slugiic_softc *sc = arg; return (i2c_bitbang_send_start(sc, flags, &sc->sc_ibo)); } static int slugiic_send_stop(void *arg, int flags) { struct slugiic_softc *sc = arg; return (i2c_bitbang_send_stop(sc, flags, &sc->sc_ibo)); } static int slugiic_initiate_xfer(void *arg, i2c_addr_t addr, int flags) { struct slugiic_softc *sc = arg; return (i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_ibo)); } static int slugiic_read_byte(void *arg, uint8_t *vp, int flags) { struct slugiic_softc *sc = arg; return (i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_ibo)); } static int slugiic_write_byte(void *arg, uint8_t v, int flags) { struct slugiic_softc *sc = arg; return (i2c_bitbang_write_byte(sc, v, flags, &sc->sc_ibo)); } static void slugiic_set_dir(void *arg, uint32_t bits) { struct slugiic_softc *sc = arg; uint32_t reg; int s; if (sc->sc_dirout == bits) return; s = splhigh(); sc->sc_dirout = bits; if (sc->sc_dirout) { /* SDA is output; enable SDA output if SDA OUTR is low */ reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOUTR); if ((reg & GPIO_I2C_SDA_BIT) == 0) { reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOER); reg &= ~GPIO_I2C_SDA_BIT; GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, reg); } } else { /* SDA is input; disable SDA output */ reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOER); reg |= GPIO_I2C_SDA_BIT; GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, reg); } splx(s); } static void slugiic_set_bits(void *arg, uint32_t bits) { struct slugiic_softc *sc = arg; uint32_t oer, outr; int s; s = splhigh(); /* * Enable SCL output if the SCL line is to be driven low. * Enable SDA output if the SDA line is to be driven low and * SDA direction is output. * Otherwise switch them to input even if directions are output * so that we can emulate open collector output with the pullup * resistors. * If lines are to be set to high, disable OER first then set OUTR. * If lines are to be set to low, set OUTR first then enable OER. */ oer = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOER); if ((bits & GPIO_I2C_SCL_BIT) != 0) oer |= GPIO_I2C_SCL_BIT; if ((bits & GPIO_I2C_SDA_BIT) != 0) oer |= GPIO_I2C_SDA_BIT; GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, oer); outr = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOUTR); outr &= ~(GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT); GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOUTR, outr | bits); if ((bits & GPIO_I2C_SCL_BIT) == 0) oer &= ~GPIO_I2C_SCL_BIT; if ((bits & GPIO_I2C_SDA_BIT) == 0 && sc->sc_dirout) oer &= ~GPIO_I2C_SDA_BIT; GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, oer); splx(s); } static uint32_t slugiic_read_bits(void *arg) { uint32_t reg; reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPINR); return (reg & (GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT)); } static void slugiic_deferred_attach(device_t self) { struct slugiic_softc *sc = device_private(self); struct i2cbus_attach_args iba; uint32_t reg; reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOUTR); reg |= GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT; GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOUTR, reg); reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOER); reg &= ~GPIO_I2C_SCL_BIT; reg |= GPIO_I2C_SDA_BIT; GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, reg); memset(&iba, 0, sizeof(iba)); iba.iba_tag = &sc->sc_ic; (void) config_found_ia(self, "i2cbus", &iba, iicbus_print); } static int slugiic_match(device_t parent, cfdata_t cf, void *aux) { return (1); } static void slugiic_attach(device_t parent, device_t self, void *aux) { struct slugiic_softc *sc = device_private(self); aprint_naive("\n"); aprint_normal(": I2C bus\n"); sc->sc_ic.ic_cookie = sc; sc->sc_ic.ic_acquire_bus = slugiic_acquire_bus; sc->sc_ic.ic_release_bus = slugiic_release_bus; sc->sc_ic.ic_exec = NULL; sc->sc_ic.ic_send_start = slugiic_send_start; sc->sc_ic.ic_send_stop = slugiic_send_stop; sc->sc_ic.ic_initiate_xfer = slugiic_initiate_xfer; sc->sc_ic.ic_read_byte = slugiic_read_byte; sc->sc_ic.ic_write_byte = slugiic_write_byte; sc->sc_ibo.ibo_set_dir = slugiic_set_dir; sc->sc_ibo.ibo_set_bits = slugiic_set_bits; sc->sc_ibo.ibo_read_bits = slugiic_read_bits; sc->sc_ibo.ibo_bits[I2C_BIT_SDA] = GPIO_I2C_SDA_BIT; sc->sc_ibo.ibo_bits[I2C_BIT_SCL] = GPIO_I2C_SCL_BIT; sc->sc_ibo.ibo_bits[I2C_BIT_OUTPUT] = 1; sc->sc_ibo.ibo_bits[I2C_BIT_INPUT] = 0; mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); sc->sc_dirout = 0; /* * Defer until ixp425_softc has been initialised */ config_interrupts(self, slugiic_deferred_attach); } CFATTACH_DECL_NEW(slugiic, sizeof(struct slugiic_softc), slugiic_match, slugiic_attach, NULL, NULL);