1 /* $NetBSD: linux_i2c.c,v 1.3 2015/03/05 17:29:18 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2015 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 1.3 2015/03/05 17:29:18 riastradh Exp $"); 34 35 #include <sys/types.h> 36 #include <sys/errno.h> 37 #include <sys/kmem.h> 38 #include <sys/queue.h> /* XXX include order botch: i2cvar.h needs */ 39 40 #include <dev/i2c/i2cvar.h> 41 #include <dev/i2c/i2c_bitbang.h> /* XXX include order botch */ 42 43 #include <linux/i2c.h> 44 #include <linux/i2c-algo-bit.h> 45 46 static int netbsd_i2c_transfer(i2c_tag_t, struct i2c_msg *, int); 47 static i2c_op_t linux_i2c_flags_op(uint16_t, bool); 48 static int linux_i2c_flags_flags(uint16_t); 49 static uint32_t linux_i2cbb_functionality(struct i2c_adapter *); 50 static int linux_i2cbb_xfer(struct i2c_adapter *, struct i2c_msg *, int); 51 static void linux_i2cbb_set_bits(void *, uint32_t); 52 static uint32_t linux_i2cbb_read_bits(void *); 53 static void linux_i2cbb_set_dir(void *, uint32_t); 54 static int linux_i2cbb_send_start(void *, int); 55 static int linux_i2cbb_send_stop(void *, int); 56 static int linux_i2cbb_initiate_xfer(void *, i2c_addr_t, int); 57 static int linux_i2cbb_read_byte(void *, uint8_t *, int); 58 static int linux_i2cbb_write_byte(void *, uint8_t, int); 59 60 /* 61 * Client operations: operations with a particular i2c slave device. 62 */ 63 64 struct i2c_client * 65 i2c_new_device(struct i2c_adapter *adapter, const struct i2c_board_info *info) 66 { 67 struct i2c_client *client; 68 69 client = kmem_alloc(sizeof(*client), KM_SLEEP); 70 client->adapter = adapter; 71 client->addr = info->addr; 72 client->flags = info->flags; 73 74 return client; 75 } 76 77 void 78 i2c_unregister_device(struct i2c_client *client) 79 { 80 81 kmem_free(client, sizeof(*client)); 82 } 83 84 int 85 i2c_master_send(const struct i2c_client *client, const char *buf, int count) 86 { 87 struct i2c_msg msg = { 88 .addr = client->addr, 89 .flags = client->flags & I2C_M_TEN, 90 .len = count, 91 .buf = __UNCONST(buf), 92 }; 93 int ret; 94 95 KASSERT(0 <= count); 96 97 ret = i2c_transfer(client->adapter, &msg, 1); 98 if (ret <= 0) 99 return ret; 100 101 return count; 102 } 103 104 int 105 i2c_master_recv(const struct i2c_client *client, char *buf, int count) 106 { 107 struct i2c_msg msg = { 108 .addr = client->addr, 109 .flags = (client->flags & I2C_M_TEN) | I2C_M_RD, 110 .len = count, 111 .buf = buf, 112 }; 113 int ret; 114 115 ret = i2c_transfer(client->adapter, &msg, 1); 116 if (ret <= 0) 117 return ret; 118 119 return count; 120 } 121 122 /* 123 * Adapter operations: operations over an i2c bus via a particular 124 * controller. 125 */ 126 127 int 128 i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int n) 129 { 130 131 return (*adapter->algo->master_xfer)(adapter, msgs, n); 132 } 133 134 static int 135 netbsd_i2c_transfer(i2c_tag_t i2c, struct i2c_msg *msgs, int n) 136 { 137 int i; 138 int error; 139 140 for (i = 0; i < n; i++) { 141 const i2c_op_t op = linux_i2c_flags_op(msgs[i].flags, 142 ((i + 1) == n)); 143 const int flags = linux_i2c_flags_flags(msgs[i].flags); 144 145 switch (op) { 146 case I2C_OP_READ: 147 case I2C_OP_READ_WITH_STOP: 148 error = iic_exec(i2c, op, msgs[i].addr, 149 NULL, 0, msgs[i].buf, msgs[i].len, flags); 150 break; 151 152 case I2C_OP_WRITE: 153 case I2C_OP_WRITE_WITH_STOP: 154 error = iic_exec(i2c, op, msgs[i].addr, 155 msgs[i].buf, msgs[i].len, NULL, 0, flags); 156 break; 157 158 default: 159 error = EINVAL; 160 } 161 162 if (error) 163 /* XXX errno NetBSD->Linux */ 164 return -error; 165 } 166 167 return n; 168 } 169 170 static i2c_op_t 171 linux_i2c_flags_op(uint16_t flags, bool stop) 172 { 173 174 if (ISSET(flags, I2C_M_RD)) 175 return (stop? I2C_OP_READ_WITH_STOP : I2C_OP_READ); 176 else 177 return (stop? I2C_OP_WRITE_WITH_STOP : I2C_OP_WRITE); 178 } 179 180 static int 181 linux_i2c_flags_flags(uint16_t flags __unused) 182 { 183 184 return 0; 185 } 186 187 /* Bit-banging */ 188 189 const struct i2c_algorithm i2c_bit_algo = { 190 .master_xfer = linux_i2cbb_xfer, 191 .functionality = linux_i2cbb_functionality, 192 }; 193 194 static uint32_t 195 linux_i2cbb_functionality(struct i2c_adapter *adapter __unused) 196 { 197 uint32_t functions = 0; 198 199 functions |= I2C_FUNC_I2C; 200 functions |= I2C_FUNC_NOSTART; 201 functions |= I2C_FUNC_SMBUS_EMUL; 202 functions |= I2C_FUNC_SMBUS_READ_BLOCK_DATA; 203 functions |= I2C_FUNC_SMBUS_BLOCK_PROC_CALL; 204 #if 0 205 functions |= I2C_FUNC_10BIT_ADDR; 206 functions |= I2C_FUNC_PROTOCOL_MANGLING; 207 #endif 208 209 return functions; 210 } 211 212 static int 213 linux_i2cbb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int n) 214 { 215 struct i2c_algo_bit_data *const abd = adapter->algo_data; 216 struct i2c_controller controller = { 217 .ic_cookie = abd, 218 .ic_send_start = linux_i2cbb_send_start, 219 .ic_send_stop = linux_i2cbb_send_stop, 220 .ic_initiate_xfer = linux_i2cbb_initiate_xfer, 221 .ic_read_byte = linux_i2cbb_read_byte, 222 .ic_write_byte = linux_i2cbb_write_byte, 223 }; 224 i2c_tag_t i2c = &controller; 225 int error; 226 227 if (abd->pre_xfer) { 228 error = (*abd->pre_xfer)(adapter); 229 if (error) 230 return error; 231 } 232 233 error = netbsd_i2c_transfer(i2c, msgs, n); 234 235 if (abd->post_xfer) 236 (*abd->post_xfer)(adapter); 237 238 return error; 239 } 240 241 #define LI2CBB_SDA 0x01 242 #define LI2CBB_SCL 0x02 243 #define LI2CBB_INPUT 0x04 244 #define LI2CBB_OUTPUT 0x08 245 246 static struct i2c_bitbang_ops linux_i2cbb_ops = { 247 .ibo_set_bits = linux_i2cbb_set_bits, 248 .ibo_set_dir = linux_i2cbb_set_dir, 249 .ibo_read_bits = linux_i2cbb_read_bits, 250 .ibo_bits = { 251 [I2C_BIT_SDA] = LI2CBB_SDA, 252 [I2C_BIT_SCL] = LI2CBB_SCL, 253 [I2C_BIT_INPUT] = LI2CBB_INPUT, 254 [I2C_BIT_OUTPUT] = LI2CBB_OUTPUT, 255 }, 256 }; 257 258 static void 259 linux_i2cbb_set_bits(void *cookie, uint32_t bits) 260 { 261 struct i2c_algo_bit_data *const abd = cookie; 262 263 (*abd->setsda)(abd->data, (ISSET(bits, LI2CBB_SDA)? 1 : 0)); 264 (*abd->setscl)(abd->data, (ISSET(bits, LI2CBB_SCL)? 1 : 0)); 265 } 266 267 static uint32_t 268 linux_i2cbb_read_bits(void *cookie) 269 { 270 struct i2c_algo_bit_data *const abd = cookie; 271 uint32_t bits = 0; 272 273 if ((*abd->getsda)(abd->data)) 274 bits |= LI2CBB_SDA; 275 if ((*abd->getscl)(abd->data)) 276 bits |= LI2CBB_SCL; 277 278 return bits; 279 } 280 281 static void 282 linux_i2cbb_set_dir(void *cookie __unused, uint32_t bits __unused) 283 { 284 /* Linux doesn't do anything here... */ 285 } 286 287 static int 288 linux_i2cbb_send_start(void *cookie, int flags) 289 { 290 291 return i2c_bitbang_send_start(cookie, flags, &linux_i2cbb_ops); 292 } 293 294 static int 295 linux_i2cbb_send_stop(void *cookie, int flags) 296 { 297 298 return i2c_bitbang_send_stop(cookie, flags, &linux_i2cbb_ops); 299 } 300 301 static int 302 linux_i2cbb_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) 303 { 304 305 return i2c_bitbang_initiate_xfer(cookie, addr, flags, 306 &linux_i2cbb_ops); 307 } 308 309 static int 310 linux_i2cbb_read_byte(void *cookie, uint8_t *bytep, int flags) 311 { 312 313 return i2c_bitbang_read_byte(cookie, bytep, flags, &linux_i2cbb_ops); 314 } 315 316 static int 317 linux_i2cbb_write_byte(void *cookie, uint8_t byte, int flags) 318 { 319 320 return i2c_bitbang_write_byte(cookie, byte, flags, &linux_i2cbb_ops); 321 } 322