| 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 | |