linux_i2c.c revision 1.2.4.2
1 /* $NetBSD: linux_i2c.c,v 1.2.4.2 2014/05/18 17:46:01 rmind 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 Taylor R. Campbell. 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 __KERNEL_RCSID(0, "$NetBSD: linux_i2c.c,v 1.2.4.2 2014/05/18 17:46:01 rmind Exp $"); 34 35 #include <sys/types.h> 36 #include <sys/errno.h> 37 #include <sys/queue.h> /* XXX include order botch: i2cvar.h needs */ 38 39 #include <dev/i2c/i2cvar.h> 40 #include <dev/i2c/i2c_bitbang.h> /* XXX include order botch */ 41 42 #include <linux/i2c.h> 43 #include <linux/i2c-algo-bit.h> 44 45 static int netbsd_i2c_transfer(i2c_tag_t, struct i2c_msg *, int); 46 static i2c_op_t linux_i2c_flags_op(uint16_t, bool); 47 static int linux_i2c_flags_flags(uint16_t); 48 static uint32_t linux_i2cbb_functionality(struct i2c_adapter *); 49 static int linux_i2cbb_xfer(struct i2c_adapter *, struct i2c_msg *, int); 50 static void linux_i2cbb_set_bits(void *, uint32_t); 51 static uint32_t linux_i2cbb_read_bits(void *); 52 static void linux_i2cbb_set_dir(void *, uint32_t); 53 static int linux_i2cbb_send_start(void *, int); 54 static int linux_i2cbb_send_stop(void *, int); 55 static int linux_i2cbb_initiate_xfer(void *, i2c_addr_t, int); 56 static int linux_i2cbb_read_byte(void *, uint8_t *, int); 57 static int linux_i2cbb_write_byte(void *, uint8_t, int); 58 59 int 61 i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int n) 62 { 63 64 return (*adapter->algo->master_xfer)(adapter, msgs, n); 65 } 66 67 static int 68 netbsd_i2c_transfer(i2c_tag_t i2c, struct i2c_msg *msgs, int n) 69 { 70 int i; 71 int error; 72 73 for (i = 0; i < n; i++) { 74 const i2c_op_t op = linux_i2c_flags_op(msgs[i].flags, 75 ((i + 1) == n)); 76 const int flags = linux_i2c_flags_flags(msgs[i].flags); 77 78 switch (op) { 79 case I2C_OP_READ: 80 case I2C_OP_READ_WITH_STOP: 81 error = iic_exec(i2c, op, msgs[i].addr, 82 NULL, 0, msgs[i].buf, msgs[i].len, flags); 83 break; 84 85 case I2C_OP_WRITE: 86 case I2C_OP_WRITE_WITH_STOP: 87 error = iic_exec(i2c, op, msgs[i].addr, 88 msgs[i].buf, msgs[i].len, NULL, 0, flags); 89 break; 90 91 default: 92 error = EINVAL; 93 } 94 95 if (error) 96 /* XXX errno NetBSD->Linux */ 97 return -error; 98 } 99 100 return n; 101 } 102 103 static i2c_op_t 104 linux_i2c_flags_op(uint16_t flags, bool stop) 105 { 106 107 if (ISSET(flags, I2C_M_RD)) 108 return (stop? I2C_OP_READ_WITH_STOP : I2C_OP_READ); 109 else 110 return (stop? I2C_OP_WRITE_WITH_STOP : I2C_OP_WRITE); 111 } 112 113 static int 114 linux_i2c_flags_flags(uint16_t flags __unused) 115 { 116 117 return 0; 118 } 119 120 const struct i2c_algorithm i2c_bit_algo = { 122 .master_xfer = linux_i2cbb_xfer, 123 .functionality = linux_i2cbb_functionality, 124 }; 125 126 static uint32_t 127 linux_i2cbb_functionality(struct i2c_adapter *adapter __unused) 128 { 129 uint32_t functions = 0; 130 131 functions |= I2C_FUNC_I2C; 132 functions |= I2C_FUNC_NOSTART; 133 functions |= I2C_FUNC_SMBUS_EMUL; 134 functions |= I2C_FUNC_SMBUS_READ_BLOCK_DATA; 135 functions |= I2C_FUNC_SMBUS_BLOCK_PROC_CALL; 136 #if 0 137 functions |= I2C_FUNC_10BIT_ADDR; 138 functions |= I2C_FUNC_PROTOCOL_MANGLING; 139 #endif 140 141 return functions; 142 } 143 144 static int 145 linux_i2cbb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int n) 146 { 147 struct i2c_algo_bit_data *const abd = adapter->algo_data; 148 struct i2c_controller controller = { 149 .ic_cookie = abd, 150 .ic_send_start = linux_i2cbb_send_start, 151 .ic_send_stop = linux_i2cbb_send_stop, 152 .ic_initiate_xfer = linux_i2cbb_initiate_xfer, 153 .ic_read_byte = linux_i2cbb_read_byte, 154 .ic_write_byte = linux_i2cbb_write_byte, 155 }; 156 i2c_tag_t i2c = &controller; 157 int error; 158 159 if (abd->pre_xfer) { 160 error = (*abd->pre_xfer)(adapter); 161 if (error) 162 return error; 163 } 164 165 error = netbsd_i2c_transfer(i2c, msgs, n); 166 167 if (abd->post_xfer) 168 (*abd->post_xfer)(adapter); 169 170 return error; 171 } 172 173 #define LI2CBB_SDA 0x01 175 #define LI2CBB_SCL 0x02 176 #define LI2CBB_INPUT 0x04 177 #define LI2CBB_OUTPUT 0x08 178 179 static struct i2c_bitbang_ops linux_i2cbb_ops = { 180 .ibo_set_bits = linux_i2cbb_set_bits, 181 .ibo_set_dir = linux_i2cbb_set_dir, 182 .ibo_read_bits = linux_i2cbb_read_bits, 183 .ibo_bits = { 184 [I2C_BIT_SDA] = LI2CBB_SDA, 185 [I2C_BIT_SCL] = LI2CBB_SCL, 186 [I2C_BIT_INPUT] = LI2CBB_INPUT, 187 [I2C_BIT_OUTPUT] = LI2CBB_OUTPUT, 188 }, 189 }; 190 191 static void 192 linux_i2cbb_set_bits(void *cookie, uint32_t bits) 193 { 194 struct i2c_algo_bit_data *const abd = cookie; 195 196 (*abd->setsda)(abd->data, (ISSET(bits, LI2CBB_SDA)? 1 : 0)); 197 (*abd->setscl)(abd->data, (ISSET(bits, LI2CBB_SCL)? 1 : 0)); 198 } 199 200 static uint32_t 201 linux_i2cbb_read_bits(void *cookie) 202 { 203 struct i2c_algo_bit_data *const abd = cookie; 204 uint32_t bits = 0; 205 206 if ((*abd->getsda)(abd->data)) 207 bits |= LI2CBB_SDA; 208 if ((*abd->getscl)(abd->data)) 209 bits |= LI2CBB_SCL; 210 211 return bits; 212 } 213 214 static void 215 linux_i2cbb_set_dir(void *cookie __unused, uint32_t bits __unused) 216 { 217 /* Linux doesn't do anything here... */ 218 } 219 220 static int 222 linux_i2cbb_send_start(void *cookie, int flags) 223 { 224 225 return i2c_bitbang_send_start(cookie, flags, &linux_i2cbb_ops); 226 } 227 228 static int 229 linux_i2cbb_send_stop(void *cookie, int flags) 230 { 231 232 return i2c_bitbang_send_stop(cookie, flags, &linux_i2cbb_ops); 233 } 234 235 static int 236 linux_i2cbb_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) 237 { 238 239 return i2c_bitbang_initiate_xfer(cookie, addr, flags, 240 &linux_i2cbb_ops); 241 } 242 243 static int 244 linux_i2cbb_read_byte(void *cookie, uint8_t *bytep, int flags) 245 { 246 247 return i2c_bitbang_read_byte(cookie, bytep, flags, &linux_i2cbb_ops); 248 } 249 250 static int 251 linux_i2cbb_write_byte(void *cookie, uint8_t byte, int flags) 252 { 253 254 return i2c_bitbang_write_byte(cookie, byte, flags, &linux_i2cbb_ops); 255 } 256
Indexes created Tue Sep 30 20:09:53 GMT 2025