1 /* $NetBSD: tsciic.c,v 1.2 2019/12/22 23:23:29 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Julian Coleman. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 34 __KERNEL_RCSID(0, "$NetBSD: tsciic.c,v 1.2 2019/12/22 23:23:29 thorpej Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/device.h> 39 40 #include <alpha/pci/tsreg.h> 41 #include <alpha/pci/tsvar.h> 42 43 #include <dev/i2c/i2cvar.h> 44 #include <dev/i2c/i2c_bitbang.h> 45 #include <dev/i2c/ddcvar.h> 46 47 /* I2C glue */ 48 static int tsciic_send_start(void *, int); 49 static int tsciic_send_stop(void *, int); 50 static int tsciic_initiate_xfer(void *, i2c_addr_t, int); 51 static int tsciic_read_byte(void *, uint8_t *, int); 52 static int tsciic_write_byte(void *, uint8_t, int); 53 54 /* I2C bitbang glue */ 55 static void tsciicbb_set_bits(void *, uint32_t); 56 static void tsciicbb_set_dir(void *, uint32_t); 57 static uint32_t tsciicbb_read(void *); 58 59 #define MPD_BIT_SDA 0x01 60 #define MPD_BIT_SCL 0x02 61 static const struct i2c_bitbang_ops tsciicbb_ops = { 62 tsciicbb_set_bits, 63 tsciicbb_set_dir, 64 tsciicbb_read, 65 { 66 MPD_BIT_SDA, 67 MPD_BIT_SCL, 68 0, 69 0 70 } 71 }; 72 73 void 74 tsciic_init(device_t self) { 75 struct tsciic_softc *sc = device_private(self); 76 struct i2cbus_attach_args iba; 77 78 iic_tag_init(&sc->sc_i2c); 79 sc->sc_i2c.ic_cookie = sc; 80 sc->sc_i2c.ic_send_start = tsciic_send_start; 81 sc->sc_i2c.ic_send_stop = tsciic_send_stop; 82 sc->sc_i2c.ic_initiate_xfer = tsciic_initiate_xfer; 83 sc->sc_i2c.ic_read_byte = tsciic_read_byte; 84 sc->sc_i2c.ic_write_byte = tsciic_write_byte; 85 86 memset(&iba, 0, sizeof(iba)); 87 iba.iba_tag = &sc->sc_i2c; 88 89 config_found_ia(self, "i2cbus", &iba, iicbus_print); 90 91 } 92 93 /* I2C bitbanging */ 94 static void 95 tsciicbb_set_bits(void *cookie, uint32_t bits) 96 { 97 uint64_t val; 98 99 val = (bits & MPD_BIT_SDA ? MPD_DS : 0) | 100 (bits & MPD_BIT_SCL ? MPD_CKS : 0); 101 alpha_mb(); 102 STQP(TS_C_MPD) = val; 103 alpha_mb(); 104 } 105 106 static void 107 tsciicbb_set_dir(void *cookie, uint32_t dir) 108 { 109 /* Nothing to do */ 110 } 111 112 static uint32_t 113 tsciicbb_read(void *cookie) 114 { 115 uint64_t val; 116 uint32_t bits; 117 118 val = LDQP(TS_C_MPD); 119 bits = (val & MPD_DR ? MPD_BIT_SDA : 0) | 120 (val & MPD_CKR ? MPD_BIT_SCL : 0); 121 return bits; 122 } 123 124 /* higher level I2C stuff */ 125 static int 126 tsciic_send_start(void *cookie, int flags) 127 { 128 return (i2c_bitbang_send_start(cookie, flags, &tsciicbb_ops)); 129 } 130 131 static int 132 tsciic_send_stop(void *cookie, int flags) 133 { 134 return (i2c_bitbang_send_stop(cookie, flags, &tsciicbb_ops)); 135 } 136 137 static int 138 tsciic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) 139 { 140 return (i2c_bitbang_initiate_xfer(cookie, addr, flags, 141 &tsciicbb_ops)); 142 } 143 144 static int 145 tsciic_read_byte(void *cookie, uint8_t *valp, int flags) 146 { 147 return (i2c_bitbang_read_byte(cookie, valp, flags, &tsciicbb_ops)); 148 } 149 150 static int 151 tsciic_write_byte(void *cookie, uint8_t val, int flags) 152 { 153 return (i2c_bitbang_write_byte(cookie, val, flags, &tsciicbb_ops)); 154 } 155