| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * FSI-attached I2C master algorithm |
| 4 | * |
| 5 | * Copyright 2018 IBM Corporation |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the License, or (at your option) any later version. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/bitfield.h> |
| 14 | #include <linux/bitops.h> |
| 15 | #include <linux/delay.h> |
| 16 | #include <linux/device.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/fsi.h> |
| 19 | #include <linux/i2c.h> |
| 20 | #include <linux/jiffies.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/list.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/mutex.h> |
| 25 | #include <linux/of.h> |
| 26 | #include <linux/slab.h> |
| 27 | |
| 28 | #define FSI_ENGID_I2C 0x7 |
| 29 | |
| 30 | #define I2C_DEFAULT_CLK_DIV 6 |
| 31 | |
| 32 | /* i2c registers */ |
| 33 | #define I2C_FSI_FIFO 0x00 |
| 34 | #define I2C_FSI_CMD 0x04 |
| 35 | #define I2C_FSI_MODE 0x08 |
| 36 | #define I2C_FSI_WATER_MARK 0x0C |
| 37 | #define I2C_FSI_INT_MASK 0x10 |
| 38 | #define I2C_FSI_INT_COND 0x14 |
| 39 | #define I2C_FSI_OR_INT_MASK 0x14 |
| 40 | #define I2C_FSI_INTS 0x18 |
| 41 | #define I2C_FSI_AND_INT_MASK 0x18 |
| 42 | #define I2C_FSI_STAT 0x1C |
| 43 | #define I2C_FSI_RESET_I2C 0x1C |
| 44 | #define I2C_FSI_ESTAT 0x20 |
| 45 | #define I2C_FSI_RESET_ERR 0x20 |
| 46 | #define I2C_FSI_RESID_LEN 0x24 |
| 47 | #define I2C_FSI_SET_SCL 0x24 |
| 48 | #define I2C_FSI_PORT_BUSY 0x28 |
| 49 | #define I2C_FSI_RESET_SCL 0x2C |
| 50 | #define I2C_FSI_SET_SDA 0x30 |
| 51 | #define I2C_FSI_RESET_SDA 0x34 |
| 52 | |
| 53 | /* cmd register */ |
| 54 | #define I2C_CMD_WITH_START BIT(31) |
| 55 | #define I2C_CMD_WITH_ADDR BIT(30) |
| 56 | #define I2C_CMD_RD_CONT BIT(29) |
| 57 | #define I2C_CMD_WITH_STOP BIT(28) |
| 58 | #define I2C_CMD_FORCELAUNCH BIT(27) |
| 59 | #define I2C_CMD_ADDR GENMASK(23, 17) |
| 60 | #define I2C_CMD_READ BIT(16) |
| 61 | #define I2C_CMD_LEN GENMASK(15, 0) |
| 62 | |
| 63 | /* mode register */ |
| 64 | #define I2C_MODE_CLKDIV GENMASK(31, 16) |
| 65 | #define I2C_MODE_PORT GENMASK(15, 10) |
| 66 | #define I2C_MODE_ENHANCED BIT(3) |
| 67 | #define I2C_MODE_DIAG BIT(2) |
| 68 | #define I2C_MODE_PACE_ALLOW BIT(1) |
| 69 | #define I2C_MODE_WRAP BIT(0) |
| 70 | |
| 71 | /* watermark register */ |
| 72 | #define I2C_WATERMARK_HI GENMASK(15, 12) |
| 73 | #define I2C_WATERMARK_LO GENMASK(7, 4) |
| 74 | |
| 75 | #define I2C_FIFO_HI_LVL 4 |
| 76 | #define I2C_FIFO_LO_LVL 4 |
| 77 | |
| 78 | /* interrupt register */ |
| 79 | #define I2C_INT_INV_CMD BIT(15) |
| 80 | #define I2C_INT_PARITY BIT(14) |
| 81 | #define I2C_INT_BE_OVERRUN BIT(13) |
| 82 | #define I2C_INT_BE_ACCESS BIT(12) |
| 83 | #define I2C_INT_LOST_ARB BIT(11) |
| 84 | #define I2C_INT_NACK BIT(10) |
| 85 | #define I2C_INT_DAT_REQ BIT(9) |
| 86 | #define I2C_INT_CMD_COMP BIT(8) |
| 87 | #define I2C_INT_STOP_ERR BIT(7) |
| 88 | #define I2C_INT_BUSY BIT(6) |
| 89 | #define I2C_INT_IDLE BIT(5) |
| 90 | |
| 91 | /* status register */ |
| 92 | #define I2C_STAT_INV_CMD BIT(31) |
| 93 | #define I2C_STAT_PARITY BIT(30) |
| 94 | #define I2C_STAT_BE_OVERRUN BIT(29) |
| 95 | #define I2C_STAT_BE_ACCESS BIT(28) |
| 96 | #define I2C_STAT_LOST_ARB BIT(27) |
| 97 | #define I2C_STAT_NACK BIT(26) |
| 98 | #define I2C_STAT_DAT_REQ BIT(25) |
| 99 | #define I2C_STAT_CMD_COMP BIT(24) |
| 100 | #define I2C_STAT_STOP_ERR BIT(23) |
| 101 | #define I2C_STAT_MAX_PORT GENMASK(19, 16) |
| 102 | #define I2C_STAT_ANY_INT BIT(15) |
| 103 | #define I2C_STAT_SCL_IN BIT(11) |
| 104 | #define I2C_STAT_SDA_IN BIT(10) |
| 105 | #define I2C_STAT_PORT_BUSY BIT(9) |
| 106 | #define I2C_STAT_SELF_BUSY BIT(8) |
| 107 | #define I2C_STAT_FIFO_COUNT GENMASK(7, 0) |
| 108 | |
| 109 | #define I2C_STAT_ERR (I2C_STAT_INV_CMD | \ |
| 110 | I2C_STAT_PARITY | \ |
| 111 | I2C_STAT_BE_OVERRUN | \ |
| 112 | I2C_STAT_BE_ACCESS | \ |
| 113 | I2C_STAT_LOST_ARB | \ |
| 114 | I2C_STAT_NACK | \ |
| 115 | I2C_STAT_STOP_ERR) |
| 116 | #define I2C_STAT_ANY_RESP (I2C_STAT_ERR | \ |
| 117 | I2C_STAT_DAT_REQ | \ |
| 118 | I2C_STAT_CMD_COMP) |
| 119 | |
| 120 | /* extended status register */ |
| 121 | #define I2C_ESTAT_FIFO_SZ GENMASK(31, 24) |
| 122 | #define I2C_ESTAT_SCL_IN_SY BIT(15) |
| 123 | #define I2C_ESTAT_SDA_IN_SY BIT(14) |
| 124 | #define I2C_ESTAT_S_SCL BIT(13) |
| 125 | #define I2C_ESTAT_S_SDA BIT(12) |
| 126 | #define I2C_ESTAT_M_SCL BIT(11) |
| 127 | #define I2C_ESTAT_M_SDA BIT(10) |
| 128 | #define I2C_ESTAT_HI_WATER BIT(9) |
| 129 | #define I2C_ESTAT_LO_WATER BIT(8) |
| 130 | #define I2C_ESTAT_PORT_BUSY BIT(7) |
| 131 | #define I2C_ESTAT_SELF_BUSY BIT(6) |
| 132 | #define I2C_ESTAT_VERSION GENMASK(4, 0) |
| 133 | |
| 134 | /* port busy register */ |
| 135 | #define I2C_PORT_BUSY_RESET BIT(31) |
| 136 | |
| 137 | /* wait for command complete or data request */ |
| 138 | #define I2C_CMD_SLEEP_MAX_US 500 |
| 139 | #define I2C_CMD_SLEEP_MIN_US 50 |
| 140 | |
| 141 | /* wait after reset; choose time from legacy driver */ |
| 142 | #define I2C_RESET_SLEEP_MAX_US 2000 |
| 143 | #define I2C_RESET_SLEEP_MIN_US 1000 |
| 144 | |
| 145 | /* choose timeout length from legacy driver; it's well tested */ |
| 146 | #define I2C_ABORT_TIMEOUT msecs_to_jiffies(100) |
| 147 | |
| 148 | struct fsi_i2c_master { |
| 149 | struct fsi_device *fsi; |
| 150 | u8 fifo_size; |
| 151 | struct list_head ports; |
| 152 | struct mutex lock; |
| 153 | }; |
| 154 | |
| 155 | struct fsi_i2c_port { |
| 156 | struct list_head list; |
| 157 | struct i2c_adapter adapter; |
| 158 | struct fsi_i2c_master *master; |
| 159 | u16 port; |
| 160 | u16 xfrd; |
| 161 | }; |
| 162 | |
| 163 | static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg, |
| 164 | u32 *data) |
| 165 | { |
| 166 | int rc; |
| 167 | __be32 data_be; |
| 168 | |
| 169 | rc = fsi_device_read(fsi, reg, &data_be, sizeof(data_be)); |
| 170 | if (rc) |
| 171 | return rc; |
| 172 | |
| 173 | *data = be32_to_cpu(data_be); |
| 174 | |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | static int fsi_i2c_write_reg(struct fsi_device *fsi, unsigned int reg, |
| 179 | u32 *data) |
| 180 | { |
| 181 | __be32 data_be = cpu_to_be32p(data); |
| 182 | |
| 183 | return fsi_device_write(fsi, reg, &data_be, sizeof(data_be)); |
| 184 | } |
| 185 | |
| 186 | static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c) |
| 187 | { |
| 188 | int rc; |
| 189 | u32 mode = I2C_MODE_ENHANCED, extended_status, watermark; |
| 190 | u32 interrupt = 0; |
| 191 | |
| 192 | /* since we use polling, disable interrupts */ |
| 193 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, &interrupt); |
| 194 | if (rc) |
| 195 | return rc; |
| 196 | |
| 197 | mode |= FIELD_PREP(I2C_MODE_CLKDIV, I2C_DEFAULT_CLK_DIV); |
| 198 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 199 | if (rc) |
| 200 | return rc; |
| 201 | |
| 202 | rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_ESTAT, &extended_status); |
| 203 | if (rc) |
| 204 | return rc; |
| 205 | |
| 206 | i2c->fifo_size = FIELD_GET(I2C_ESTAT_FIFO_SZ, extended_status); |
| 207 | watermark = FIELD_PREP(I2C_WATERMARK_HI, |
| 208 | i2c->fifo_size - I2C_FIFO_HI_LVL); |
| 209 | watermark |= FIELD_PREP(I2C_WATERMARK_LO, I2C_FIFO_LO_LVL); |
| 210 | |
| 211 | return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_WATER_MARK, &watermark); |
| 212 | } |
| 213 | |
| 214 | static int fsi_i2c_set_port(struct fsi_i2c_port *port) |
| 215 | { |
| 216 | int rc; |
| 217 | struct fsi_device *fsi = port->master->fsi; |
| 218 | u32 mode, dummy = 0; |
| 219 | |
| 220 | rc = fsi_i2c_read_reg(fsi, I2C_FSI_MODE, &mode); |
| 221 | if (rc) |
| 222 | return rc; |
| 223 | |
| 224 | if (FIELD_GET(I2C_MODE_PORT, mode) == port->port) |
| 225 | return 0; |
| 226 | |
| 227 | mode = (mode & ~I2C_MODE_PORT) | FIELD_PREP(I2C_MODE_PORT, port->port); |
| 228 | rc = fsi_i2c_write_reg(fsi, I2C_FSI_MODE, &mode); |
| 229 | if (rc) |
| 230 | return rc; |
| 231 | |
| 232 | /* reset engine when port is changed */ |
| 233 | return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy); |
| 234 | } |
| 235 | |
| 236 | static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg, |
| 237 | bool stop) |
| 238 | { |
| 239 | struct fsi_i2c_master *i2c = port->master; |
| 240 | u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR; |
| 241 | |
| 242 | port->xfrd = 0; |
| 243 | |
| 244 | if (msg->flags & I2C_M_RD) |
| 245 | cmd |= I2C_CMD_READ; |
| 246 | |
| 247 | if (stop || msg->flags & I2C_M_STOP) |
| 248 | cmd |= I2C_CMD_WITH_STOP; |
| 249 | |
| 250 | cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr); |
| 251 | cmd |= FIELD_PREP(I2C_CMD_LEN, msg->len); |
| 252 | |
| 253 | return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, &cmd); |
| 254 | } |
| 255 | |
| 256 | static int fsi_i2c_get_op_bytes(int op_bytes) |
| 257 | { |
| 258 | /* fsi is limited to max 4 byte aligned ops */ |
| 259 | if (op_bytes > 4) |
| 260 | return 4; |
| 261 | else if (op_bytes == 3) |
| 262 | return 2; |
| 263 | return op_bytes; |
| 264 | } |
| 265 | |
| 266 | static int fsi_i2c_write_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, |
| 267 | u8 fifo_count) |
| 268 | { |
| 269 | int write; |
| 270 | int rc; |
| 271 | struct fsi_i2c_master *i2c = port->master; |
| 272 | int bytes_to_write = i2c->fifo_size - fifo_count; |
| 273 | int bytes_remaining = msg->len - port->xfrd; |
| 274 | |
| 275 | bytes_to_write = min(bytes_to_write, bytes_remaining); |
| 276 | |
| 277 | while (bytes_to_write) { |
| 278 | write = fsi_i2c_get_op_bytes(bytes_to_write); |
| 279 | |
| 280 | rc = fsi_device_write(i2c->fsi, I2C_FSI_FIFO, |
| 281 | &msg->buf[port->xfrd], write); |
| 282 | if (rc) |
| 283 | return rc; |
| 284 | |
| 285 | port->xfrd += write; |
| 286 | bytes_to_write -= write; |
| 287 | } |
| 288 | |
| 289 | return 0; |
| 290 | } |
| 291 | |
| 292 | static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, |
| 293 | u8 fifo_count) |
| 294 | { |
| 295 | int read; |
| 296 | int rc; |
| 297 | struct fsi_i2c_master *i2c = port->master; |
| 298 | int bytes_to_read; |
| 299 | int xfr_remaining = msg->len - port->xfrd; |
| 300 | u32 dummy; |
| 301 | |
| 302 | bytes_to_read = min_t(int, fifo_count, xfr_remaining); |
| 303 | |
| 304 | while (bytes_to_read) { |
| 305 | read = fsi_i2c_get_op_bytes(bytes_to_read); |
| 306 | |
| 307 | if (xfr_remaining) { |
| 308 | rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, |
| 309 | &msg->buf[port->xfrd], read); |
| 310 | if (rc) |
| 311 | return rc; |
| 312 | |
| 313 | port->xfrd += read; |
| 314 | xfr_remaining -= read; |
| 315 | } else { |
| 316 | /* no more buffer but data in fifo, need to clear it */ |
| 317 | rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, &dummy, |
| 318 | read); |
| 319 | if (rc) |
| 320 | return rc; |
| 321 | } |
| 322 | |
| 323 | bytes_to_read -= read; |
| 324 | } |
| 325 | |
| 326 | return 0; |
| 327 | } |
| 328 | |
| 329 | static int fsi_i2c_get_scl(struct i2c_adapter *adap) |
| 330 | { |
| 331 | u32 stat = 0; |
| 332 | struct fsi_i2c_port *port = adap->algo_data; |
| 333 | struct fsi_i2c_master *i2c = port->master; |
| 334 | |
| 335 | fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat); |
| 336 | |
| 337 | return !!(stat & I2C_STAT_SCL_IN); |
| 338 | } |
| 339 | |
| 340 | static void fsi_i2c_set_scl(struct i2c_adapter *adap, int val) |
| 341 | { |
| 342 | u32 dummy = 0; |
| 343 | struct fsi_i2c_port *port = adap->algo_data; |
| 344 | struct fsi_i2c_master *i2c = port->master; |
| 345 | |
| 346 | if (val) |
| 347 | fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy); |
| 348 | else |
| 349 | fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy); |
| 350 | } |
| 351 | |
| 352 | static int fsi_i2c_get_sda(struct i2c_adapter *adap) |
| 353 | { |
| 354 | u32 stat = 0; |
| 355 | struct fsi_i2c_port *port = adap->algo_data; |
| 356 | struct fsi_i2c_master *i2c = port->master; |
| 357 | |
| 358 | fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat); |
| 359 | |
| 360 | return !!(stat & I2C_STAT_SDA_IN); |
| 361 | } |
| 362 | |
| 363 | static void fsi_i2c_set_sda(struct i2c_adapter *adap, int val) |
| 364 | { |
| 365 | u32 dummy = 0; |
| 366 | struct fsi_i2c_port *port = adap->algo_data; |
| 367 | struct fsi_i2c_master *i2c = port->master; |
| 368 | |
| 369 | if (val) |
| 370 | fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy); |
| 371 | else |
| 372 | fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy); |
| 373 | } |
| 374 | |
| 375 | static void fsi_i2c_prepare_recovery(struct i2c_adapter *adap) |
| 376 | { |
| 377 | int rc; |
| 378 | u32 mode; |
| 379 | struct fsi_i2c_port *port = adap->algo_data; |
| 380 | struct fsi_i2c_master *i2c = port->master; |
| 381 | |
| 382 | rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 383 | if (rc) |
| 384 | return; |
| 385 | |
| 386 | mode |= I2C_MODE_DIAG; |
| 387 | fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 388 | } |
| 389 | |
| 390 | static void fsi_i2c_unprepare_recovery(struct i2c_adapter *adap) |
| 391 | { |
| 392 | int rc; |
| 393 | u32 mode; |
| 394 | struct fsi_i2c_port *port = adap->algo_data; |
| 395 | struct fsi_i2c_master *i2c = port->master; |
| 396 | |
| 397 | rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 398 | if (rc) |
| 399 | return; |
| 400 | |
| 401 | mode &= ~I2C_MODE_DIAG; |
| 402 | fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 403 | } |
| 404 | |
| 405 | static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c, |
| 406 | struct fsi_i2c_port *port) |
| 407 | { |
| 408 | int rc; |
| 409 | u32 stat, dummy = 0; |
| 410 | |
| 411 | /* force bus reset, ignore errors */ |
| 412 | i2c_recover_bus(&port->adapter); |
| 413 | |
| 414 | /* reset errors */ |
| 415 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy); |
| 416 | if (rc) |
| 417 | return rc; |
| 418 | |
| 419 | /* wait for command complete */ |
| 420 | usleep_range(I2C_RESET_SLEEP_MIN_US, I2C_RESET_SLEEP_MAX_US); |
| 421 | |
| 422 | rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat); |
| 423 | if (rc) |
| 424 | return rc; |
| 425 | |
| 426 | if (stat & I2C_STAT_CMD_COMP) |
| 427 | return 0; |
| 428 | |
| 429 | /* failed to get command complete; reset engine again */ |
| 430 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy); |
| 431 | if (rc) |
| 432 | return rc; |
| 433 | |
| 434 | /* re-init engine again */ |
| 435 | return fsi_i2c_dev_init(i2c); |
| 436 | } |
| 437 | |
| 438 | static int fsi_i2c_reset_engine(struct fsi_i2c_master *i2c, u16 port) |
| 439 | { |
| 440 | int rc; |
| 441 | u32 mode, dummy = 0; |
| 442 | |
| 443 | /* reset engine */ |
| 444 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy); |
| 445 | if (rc) |
| 446 | return rc; |
| 447 | |
| 448 | /* re-init engine */ |
| 449 | rc = fsi_i2c_dev_init(i2c); |
| 450 | if (rc) |
| 451 | return rc; |
| 452 | |
| 453 | rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 454 | if (rc) |
| 455 | return rc; |
| 456 | |
| 457 | /* set port; default after reset is 0 */ |
| 458 | if (port) { |
| 459 | mode &= ~I2C_MODE_PORT; |
| 460 | mode |= FIELD_PREP(I2C_MODE_PORT, port); |
| 461 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 462 | if (rc) |
| 463 | return rc; |
| 464 | } |
| 465 | |
| 466 | /* reset busy register; hw workaround */ |
| 467 | dummy = I2C_PORT_BUSY_RESET; |
| 468 | rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_PORT_BUSY, &dummy); |
| 469 | if (rc) |
| 470 | return rc; |
| 471 | |
| 472 | return 0; |
| 473 | } |
| 474 | |
| 475 | static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status) |
| 476 | { |
| 477 | int rc; |
| 478 | unsigned long start; |
| 479 | u32 cmd = I2C_CMD_WITH_STOP; |
| 480 | u32 stat; |
| 481 | struct fsi_i2c_master *i2c = port->master; |
| 482 | struct fsi_device *fsi = i2c->fsi; |
| 483 | |
| 484 | rc = fsi_i2c_reset_engine(i2c, port->port); |
| 485 | if (rc) |
| 486 | return rc; |
| 487 | |
| 488 | rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &stat); |
| 489 | if (rc) |
| 490 | return rc; |
| 491 | |
| 492 | /* if sda is low, peform full bus reset */ |
| 493 | if (!(stat & I2C_STAT_SDA_IN)) { |
| 494 | rc = fsi_i2c_reset_bus(i2c, port); |
| 495 | if (rc) |
| 496 | return rc; |
| 497 | } |
| 498 | |
| 499 | /* skip final stop command for these errors */ |
| 500 | if (status & (I2C_STAT_PARITY | I2C_STAT_LOST_ARB | I2C_STAT_STOP_ERR)) |
| 501 | return 0; |
| 502 | |
| 503 | /* write stop command */ |
| 504 | rc = fsi_i2c_write_reg(fsi, I2C_FSI_CMD, &cmd); |
| 505 | if (rc) |
| 506 | return rc; |
| 507 | |
| 508 | /* wait until we see command complete in the master */ |
| 509 | start = jiffies; |
| 510 | |
| 511 | do { |
| 512 | rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &status); |
| 513 | if (rc) |
| 514 | return rc; |
| 515 | |
| 516 | if (status & I2C_STAT_CMD_COMP) |
| 517 | return 0; |
| 518 | |
| 519 | usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US); |
| 520 | } while (time_after(start + I2C_ABORT_TIMEOUT, jiffies)); |
| 521 | |
| 522 | return -ETIMEDOUT; |
| 523 | } |
| 524 | |
| 525 | static int fsi_i2c_handle_status(struct fsi_i2c_port *port, |
| 526 | struct i2c_msg *msg, u32 status) |
| 527 | { |
| 528 | int rc; |
| 529 | u8 fifo_count; |
| 530 | |
| 531 | if (status & I2C_STAT_ERR) { |
| 532 | rc = fsi_i2c_abort(port, status); |
| 533 | if (rc) |
| 534 | return rc; |
| 535 | |
| 536 | if (status & I2C_STAT_INV_CMD) |
| 537 | return -EINVAL; |
| 538 | |
| 539 | if (status & (I2C_STAT_PARITY | I2C_STAT_BE_OVERRUN | |
| 540 | I2C_STAT_BE_ACCESS)) |
| 541 | return -EPROTO; |
| 542 | |
| 543 | if (status & I2C_STAT_NACK) |
| 544 | return -ENXIO; |
| 545 | |
| 546 | if (status & I2C_STAT_LOST_ARB) |
| 547 | return -EAGAIN; |
| 548 | |
| 549 | if (status & I2C_STAT_STOP_ERR) |
| 550 | return -EBADMSG; |
| 551 | |
| 552 | return -EIO; |
| 553 | } |
| 554 | |
| 555 | if (status & I2C_STAT_DAT_REQ) { |
| 556 | fifo_count = FIELD_GET(I2C_STAT_FIFO_COUNT, status); |
| 557 | |
| 558 | if (msg->flags & I2C_M_RD) |
| 559 | return fsi_i2c_read_fifo(port, msg, fifo_count); |
| 560 | |
| 561 | return fsi_i2c_write_fifo(port, msg, fifo_count); |
| 562 | } |
| 563 | |
| 564 | if (status & I2C_STAT_CMD_COMP) { |
| 565 | if (port->xfrd < msg->len) |
| 566 | return -ENODATA; |
| 567 | |
| 568 | return msg->len; |
| 569 | } |
| 570 | |
| 571 | return 0; |
| 572 | } |
| 573 | |
| 574 | static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg, |
| 575 | unsigned long timeout) |
| 576 | { |
| 577 | u32 status = 0; |
| 578 | int rc; |
| 579 | unsigned long start = jiffies; |
| 580 | |
| 581 | do { |
| 582 | rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT, |
| 583 | &status); |
| 584 | if (rc) |
| 585 | return rc; |
| 586 | |
| 587 | if (status & I2C_STAT_ANY_RESP) { |
| 588 | rc = fsi_i2c_handle_status(port, msg, status); |
| 589 | if (rc < 0) |
| 590 | return rc; |
| 591 | |
| 592 | /* cmd complete and all data xfrd */ |
| 593 | if (rc == msg->len) |
| 594 | return 0; |
| 595 | |
| 596 | /* need to xfr more data, but maybe don't need wait */ |
| 597 | continue; |
| 598 | } |
| 599 | |
| 600 | usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US); |
| 601 | } while (time_after(start + timeout, jiffies)); |
| 602 | |
| 603 | return -ETIMEDOUT; |
| 604 | } |
| 605 | |
| 606 | static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, |
| 607 | int num) |
| 608 | { |
| 609 | int i, rc; |
| 610 | unsigned long start_time; |
| 611 | struct fsi_i2c_port *port = adap->algo_data; |
| 612 | struct fsi_i2c_master *master = port->master; |
| 613 | struct i2c_msg *msg; |
| 614 | |
| 615 | mutex_lock(&master->lock); |
| 616 | |
| 617 | rc = fsi_i2c_set_port(port); |
| 618 | if (rc) |
| 619 | goto unlock; |
| 620 | |
| 621 | for (i = 0; i < num; i++) { |
| 622 | msg = msgs + i; |
| 623 | start_time = jiffies; |
| 624 | |
| 625 | rc = fsi_i2c_start(port, msg, i == num - 1); |
| 626 | if (rc) |
| 627 | goto unlock; |
| 628 | |
| 629 | rc = fsi_i2c_wait(port, msg, |
| 630 | adap->timeout - (jiffies - start_time)); |
| 631 | if (rc) |
| 632 | goto unlock; |
| 633 | } |
| 634 | |
| 635 | unlock: |
| 636 | mutex_unlock(&master->lock); |
| 637 | return rc ? : num; |
| 638 | } |
| 639 | |
| 640 | static u32 fsi_i2c_functionality(struct i2c_adapter *adap) |
| 641 | { |
| 642 | return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | |
| 643 | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; |
| 644 | } |
| 645 | |
| 646 | static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = { |
| 647 | .recover_bus = i2c_generic_scl_recovery, |
| 648 | .get_scl = fsi_i2c_get_scl, |
| 649 | .set_scl = fsi_i2c_set_scl, |
| 650 | .get_sda = fsi_i2c_get_sda, |
| 651 | .set_sda = fsi_i2c_set_sda, |
| 652 | .prepare_recovery = fsi_i2c_prepare_recovery, |
| 653 | .unprepare_recovery = fsi_i2c_unprepare_recovery, |
| 654 | }; |
| 655 | |
| 656 | static const struct i2c_algorithm fsi_i2c_algorithm = { |
| 657 | .master_xfer = fsi_i2c_xfer, |
| 658 | .functionality = fsi_i2c_functionality, |
| 659 | }; |
| 660 | |
| 661 | static int fsi_i2c_probe(struct device *dev) |
| 662 | { |
| 663 | struct fsi_i2c_master *i2c; |
| 664 | struct fsi_i2c_port *port; |
| 665 | struct device_node *np; |
| 666 | int rc; |
| 667 | u32 port_no; |
| 668 | |
| 669 | i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); |
| 670 | if (!i2c) |
| 671 | return -ENOMEM; |
| 672 | |
| 673 | mutex_init(&i2c->lock); |
| 674 | i2c->fsi = to_fsi_dev(dev); |
| 675 | INIT_LIST_HEAD(&i2c->ports); |
| 676 | |
| 677 | rc = fsi_i2c_dev_init(i2c); |
| 678 | if (rc) |
| 679 | return rc; |
| 680 | |
| 681 | /* Add adapter for each i2c port of the master. */ |
| 682 | for_each_available_child_of_node(dev->of_node, np) { |
| 683 | rc = of_property_read_u32(np, "reg", &port_no); |
| 684 | if (rc || port_no > USHRT_MAX) |
| 685 | continue; |
| 686 | |
| 687 | port = kzalloc(sizeof(*port), GFP_KERNEL); |
| 688 | if (!port) |
| 689 | break; |
| 690 | |
| 691 | port->master = i2c; |
| 692 | port->port = port_no; |
| 693 | |
| 694 | port->adapter.owner = THIS_MODULE; |
| 695 | port->adapter.dev.of_node = np; |
| 696 | port->adapter.dev.parent = dev; |
| 697 | port->adapter.algo = &fsi_i2c_algorithm; |
| 698 | port->adapter.bus_recovery_info = &fsi_i2c_bus_recovery_info; |
| 699 | port->adapter.algo_data = port; |
| 700 | |
| 701 | snprintf(port->adapter.name, sizeof(port->adapter.name), |
| 702 | "i2c_bus-%u", port_no); |
| 703 | |
| 704 | rc = i2c_add_adapter(&port->adapter); |
| 705 | if (rc < 0) { |
| 706 | dev_err(dev, "Failed to register adapter: %d\n", rc); |
| 707 | kfree(port); |
| 708 | continue; |
| 709 | } |
| 710 | |
| 711 | list_add(&port->list, &i2c->ports); |
| 712 | } |
| 713 | |
| 714 | dev_set_drvdata(dev, i2c); |
| 715 | |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | static int fsi_i2c_remove(struct device *dev) |
| 720 | { |
| 721 | struct fsi_i2c_master *i2c = dev_get_drvdata(dev); |
| 722 | struct fsi_i2c_port *port, *tmp; |
| 723 | |
| 724 | list_for_each_entry_safe(port, tmp, &i2c->ports, list) { |
| 725 | list_del(&port->list); |
| 726 | i2c_del_adapter(&port->adapter); |
| 727 | kfree(port); |
| 728 | } |
| 729 | |
| 730 | return 0; |
| 731 | } |
| 732 | |
| 733 | static const struct fsi_device_id fsi_i2c_ids[] = { |
| 734 | { FSI_ENGID_I2C, FSI_VERSION_ANY }, |
| 735 | { } |
| 736 | }; |
| 737 | |
| 738 | static struct fsi_driver fsi_i2c_driver = { |
| 739 | .id_table = fsi_i2c_ids, |
| 740 | .drv = { |
| 741 | .name = "i2c-fsi", |
| 742 | .bus = &fsi_bus_type, |
| 743 | .probe = fsi_i2c_probe, |
| 744 | .remove = fsi_i2c_remove, |
| 745 | }, |
| 746 | }; |
| 747 | |
| 748 | module_fsi_driver(fsi_i2c_driver); |
| 749 | |
| 750 | MODULE_AUTHOR("Eddie James <eajames@us.ibm.com>"); |
| 751 | MODULE_DESCRIPTION("FSI attached I2C master"); |
| 752 | MODULE_LICENSE("GPL"); |