1 /* $NetBSD: iomdiic.c,v 1.8 2016/02/14 19:54:20 chs Exp $ */ 2 3 /* 4 * Copyright (c) 2003 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Jason R. Thorpe for Wasabi Systems, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <sys/param.h> 39 #include <sys/device.h> 40 #include <sys/kernel.h> 41 #include <sys/systm.h> 42 #include <sys/mutex.h> 43 #include <sys/bus.h> 44 #include <sys/cpu.h> 45 46 #include <arm/iomd/iomdreg.h> 47 #include <arm/iomd/iomdvar.h> 48 49 #include <dev/i2c/i2cvar.h> 50 #include <dev/i2c/i2c_bitbang.h> 51 52 #include <arm/iomd/iomdiicvar.h> 53 54 struct iomdiic_softc { 55 device_t sc_dev; 56 bus_space_tag_t sc_st; 57 bus_space_handle_t sc_sh; 58 59 struct i2c_controller sc_i2c; 60 kmutex_t sc_buslock; 61 62 /* 63 * The SDA pin is open-drain, so we make it an input by 64 * writing a 1 to it. 65 */ 66 uint8_t sc_iomd_iocr; 67 }; 68 69 static int iomdiic_acquire_bus(void *, int); 70 static void iomdiic_release_bus(void *, int); 71 72 static int iomdiic_send_start(void *, int); 73 static int iomdiic_send_stop(void *, int); 74 static int iomdiic_initiate_xfer(void *, i2c_addr_t, int); 75 static int iomdiic_read_byte(void *, uint8_t *, int); 76 static int iomdiic_write_byte(void *, uint8_t, int); 77 78 #define IOMDIIC_READ *(volatile uint8_t *)(IOMD_ADDRESS(IOMD_IOCR)) 79 #define IOMDIIC_WRITE(x) *(volatile uint8_t *)(IOMD_ADDRESS(IOMD_IOCR)) = (x) 80 81 #define IOMD_IOCR_SDA 0x01 82 #define IOMD_IOCR_SCL 0x02 83 84 static void 85 iomdiic_bb_set_bits(void *cookie, uint32_t bits) 86 { 87 struct iomdiic_softc *sc = cookie; 88 89 IOMDIIC_WRITE((IOMDIIC_READ & ~(IOMD_IOCR_SDA|IOMD_IOCR_SCL)) | 90 sc->sc_iomd_iocr | bits); 91 } 92 93 static void 94 iomdiic_bb_set_dir(void *cookie, uint32_t bits) 95 { 96 struct iomdiic_softc *sc = cookie; 97 98 sc->sc_iomd_iocr = bits; 99 } 100 101 static uint32_t 102 iomdiic_bb_read_bits(void *cookie) 103 { 104 105 return (IOMDIIC_READ); 106 } 107 108 static const struct i2c_bitbang_ops iomdiic_bbops = { 109 iomdiic_bb_set_bits, 110 iomdiic_bb_set_dir, 111 iomdiic_bb_read_bits, 112 { 113 IOMD_IOCR_SDA, /* SDA */ 114 IOMD_IOCR_SCL, /* SCL */ 115 0, /* SDA is output */ 116 IOMD_IOCR_SDA, /* SDA is input */ 117 } 118 }; 119 120 static int 121 iomdiic_match(device_t parent, cfdata_t cf, void *aux) 122 { 123 struct iic_attach_args *ia = aux; 124 125 if (strcmp(ia->ia_name, "iic") == 0) return 1; 126 return 0; 127 } 128 129 static void 130 iomdiic_attach(device_t parent, device_t self, void *aux) 131 { 132 struct iomdiic_softc *sc = device_private(self); 133 struct i2cbus_attach_args iba; 134 135 aprint_normal("\n"); 136 137 sc->sc_dev = self; 138 139 mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE); 140 141 sc->sc_i2c.ic_cookie = sc; 142 sc->sc_i2c.ic_acquire_bus = iomdiic_acquire_bus; 143 sc->sc_i2c.ic_release_bus = iomdiic_release_bus; 144 sc->sc_i2c.ic_send_start = iomdiic_send_start; 145 sc->sc_i2c.ic_send_stop = iomdiic_send_stop; 146 sc->sc_i2c.ic_initiate_xfer = iomdiic_initiate_xfer; 147 sc->sc_i2c.ic_read_byte = iomdiic_read_byte; 148 sc->sc_i2c.ic_write_byte = iomdiic_write_byte; 149 150 memset(&iba, 0, sizeof(iba)); 151 iba.iba_tag = &sc->sc_i2c; 152 (void) config_found_ia(sc->sc_dev, "i2cbus", &iba, iicbus_print); 153 } 154 155 CFATTACH_DECL_NEW(iomdiic, sizeof(struct iomdiic_softc), 156 iomdiic_match, iomdiic_attach, NULL, NULL); 157 158 i2c_tag_t 159 iomdiic_bootstrap_cookie(void) 160 { 161 static struct iomdiic_softc sc; 162 static struct device dev; 163 164 /* XXX Yuck. */ 165 strcpy(dev.dv_xname, "iomdiicboot"); 166 167 sc.sc_dev = &dev; 168 sc.sc_i2c.ic_cookie = ≻ 169 sc.sc_i2c.ic_acquire_bus = iomdiic_acquire_bus; 170 sc.sc_i2c.ic_release_bus = iomdiic_release_bus; 171 sc.sc_i2c.ic_send_start = iomdiic_send_start; 172 sc.sc_i2c.ic_send_stop = iomdiic_send_stop; 173 sc.sc_i2c.ic_initiate_xfer = iomdiic_initiate_xfer; 174 sc.sc_i2c.ic_read_byte = iomdiic_read_byte; 175 sc.sc_i2c.ic_write_byte = iomdiic_write_byte; 176 177 return ((void *) &sc.sc_i2c); 178 } 179 180 static int 181 iomdiic_acquire_bus(void *cookie, int flags) 182 { 183 struct iomdiic_softc *sc = cookie; 184 185 /* XXX What should we do for the polling case? */ 186 if (flags & I2C_F_POLL) 187 return (0); 188 189 mutex_enter(&sc->sc_buslock); 190 return (0); 191 } 192 193 static void 194 iomdiic_release_bus(void *cookie, int flags) 195 { 196 struct iomdiic_softc *sc = cookie; 197 198 /* XXX See above. */ 199 if (flags & I2C_F_POLL) 200 return; 201 202 mutex_exit(&sc->sc_buslock); 203 } 204 205 static int 206 iomdiic_send_start(void *cookie, int flags) 207 { 208 209 return (i2c_bitbang_send_start(cookie, flags, &iomdiic_bbops)); 210 } 211 212 static int 213 iomdiic_send_stop(void *cookie, int flags) 214 { 215 216 return (i2c_bitbang_send_stop(cookie, flags, &iomdiic_bbops)); 217 } 218 219 static int 220 iomdiic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) 221 { 222 223 return (i2c_bitbang_initiate_xfer(cookie, addr, flags, &iomdiic_bbops)); 224 } 225 226 static int 227 iomdiic_read_byte(void *cookie, uint8_t *bytep, int flags) 228 { 229 230 return (i2c_bitbang_read_byte(cookie, bytep, flags, &iomdiic_bbops)); 231 } 232 233 static int 234 iomdiic_write_byte(void *cookie, uint8_t byte, int flags) 235 { 236 237 return (i2c_bitbang_write_byte(cookie, byte, flags, &iomdiic_bbops)); 238 } 239