1 /* $NetBSD: spdmem_i2c.c,v 1.1 2010/03/24 00:31:41 pgoyette Exp $ */ 2 3 /* 4 * Copyright (c) 2007 Nicolas Joly 5 * Copyright (c) 2007 Paul Goyette 6 * Copyright (c) 2007 Tobias Nygren 7 * All rights reserved. 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. The name of the author may not be used to endorse or promote products 18 * derived from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Serial Presence Detect (SPD) memory identification 35 */ 36 37 #include <sys/cdefs.h> 38 __KERNEL_RCSID(0, "$NetBSD: spdmem_i2c.c,v 1.1 2010/03/24 00:31:41 pgoyette Exp $"); 39 40 #include <sys/param.h> 41 #include <sys/device.h> 42 #include <sys/endian.h> 43 #include <sys/sysctl.h> 44 #include <machine/bswap.h> 45 46 #include <dev/i2c/i2cvar.h> 47 #include <dev/ic/spdmemreg.h> 48 #include <dev/ic/spdmemvar.h> 49 50 /* Constants for matching i2c bus address */ 51 #define SPDMEM_I2C_ADDRMASK 0x78 52 #define SPDMEM_I2C_ADDR 0x50 53 54 struct spdmem_i2c_softc { 55 struct spdmem_softc sc_base; 56 i2c_tag_t sc_tag; 57 i2c_addr_t sc_addr; 58 }; 59 60 static int spdmem_i2c_match(device_t, cfdata_t, void *); 61 static void spdmem_i2c_attach(device_t, device_t, void *); 62 SYSCTL_SETUP_PROTO(sysctl_spdmem_setup); 63 64 static uint8_t spdmem_i2c_read(struct spdmem_softc *, uint8_t); 65 66 CFATTACH_DECL_NEW(spdmem_iic, sizeof(struct spdmem_i2c_softc), 67 spdmem_i2c_match, spdmem_i2c_attach, NULL, NULL); 68 69 static int 70 spdmem_i2c_match(device_t parent, cfdata_t match, void *aux) 71 { 72 struct i2c_attach_args *ia = aux; 73 struct spdmem_i2c_softc sc; 74 75 if (ia->ia_name) { 76 /* add other names as we find more firmware variations */ 77 if (strcmp(ia->ia_name, "dimm-spd")) 78 return 0; 79 } 80 81 /* only do this lame test when not using direct config */ 82 if (ia->ia_name == NULL) { 83 if ((ia->ia_addr & SPDMEM_I2C_ADDRMASK) != SPDMEM_I2C_ADDR) 84 return 0; 85 } 86 87 sc.sc_tag = ia->ia_tag; 88 sc.sc_addr = ia->ia_addr; 89 sc.sc_base.sc_read = spdmem_i2c_read; 90 91 return spdmem_common_probe(&sc.sc_base); 92 } 93 94 static void 95 spdmem_i2c_attach(device_t parent, device_t self, void *aux) 96 { 97 struct spdmem_i2c_softc *sc = device_private(self); 98 struct i2c_attach_args *ia = aux; 99 100 sc->sc_tag = ia->ia_tag; 101 sc->sc_addr = ia->ia_addr; 102 sc->sc_base.sc_read = spdmem_i2c_read; 103 104 if (!pmf_device_register(self, NULL, NULL)) 105 aprint_error_dev(self, "couldn't establish power handler\n"); 106 107 spdmem_common_attach(&sc->sc_base, self); 108 } 109 110 static uint8_t 111 spdmem_i2c_read(struct spdmem_softc *softc, uint8_t reg) 112 { 113 uint8_t val; 114 struct spdmem_i2c_softc *sc = (struct spdmem_i2c_softc *)softc; 115 116 iic_acquire_bus(sc->sc_tag, 0); 117 iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, ®, 1, 118 &val, 1, 0); 119 iic_release_bus(sc->sc_tag, 0); 120 121 return val; 122 } 123