Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 1 | /* |
| 2 | * linux/drivers/i2c/busses/i2c-nuc900.c |
| 3 | * |
| 4 | * Copyright (c) 2010 Nuvoton technology corporation. |
| 5 | * |
| 6 | * This driver based on S3C2410 I2C driver of Ben Dooks <ben-Y5A6D6n0/KfQXOPxS62xeg@public.gmane.org>. |
| 7 | * Written by Wan ZongShun <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation;version 2 of the License. |
| 12 | * |
| 13 | */ |
| 14 | |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/module.h> |
| 17 | |
| 18 | #include <linux/i2c.h> |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 19 | #include <linux/init.h> |
| 20 | #include <linux/time.h> |
| 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/delay.h> |
| 23 | #include <linux/errno.h> |
| 24 | #include <linux/err.h> |
| 25 | #include <linux/platform_device.h> |
| 26 | #include <linux/clk.h> |
| 27 | #include <linux/cpufreq.h> |
| 28 | #include <linux/slab.h> |
| 29 | #include <linux/io.h> |
| 30 | |
| 31 | #include <mach/mfp.h> |
Arnd Bergmann | 54ecf4f | 2012-08-24 15:18:36 +0200 | [diff] [blame] | 32 | #include <linux/platform_data/i2c-nuc900.h> |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 33 | |
| 34 | /* nuc900 i2c registers offset */ |
| 35 | |
| 36 | #define CSR 0x00 |
| 37 | #define DIVIDER 0x04 |
| 38 | #define CMDR 0x08 |
| 39 | #define SWR 0x0C |
| 40 | #define RXR 0x10 |
| 41 | #define TXR 0x14 |
| 42 | |
| 43 | /* nuc900 i2c CSR register bits */ |
| 44 | |
| 45 | #define IRQEN 0x003 |
| 46 | #define I2CBUSY 0x400 |
| 47 | #define I2CSTART 0x018 |
| 48 | #define IRQFLAG 0x004 |
| 49 | #define ARBIT_LOST 0x200 |
| 50 | #define SLAVE_ACK 0x800 |
| 51 | |
| 52 | /* nuc900 i2c CMDR register bits */ |
| 53 | |
| 54 | #define I2C_CMD_START 0x10 |
| 55 | #define I2C_CMD_STOP 0x08 |
| 56 | #define I2C_CMD_READ 0x04 |
| 57 | #define I2C_CMD_WRITE 0x02 |
| 58 | #define I2C_CMD_NACK 0x01 |
| 59 | |
| 60 | /* i2c controller state */ |
| 61 | |
| 62 | enum nuc900_i2c_state { |
| 63 | STATE_IDLE, |
| 64 | STATE_START, |
| 65 | STATE_READ, |
| 66 | STATE_WRITE, |
| 67 | STATE_STOP |
| 68 | }; |
| 69 | |
| 70 | /* i2c controller private data */ |
| 71 | |
| 72 | struct nuc900_i2c { |
| 73 | spinlock_t lock; |
| 74 | wait_queue_head_t wait; |
| 75 | |
| 76 | struct i2c_msg *msg; |
| 77 | unsigned int msg_num; |
| 78 | unsigned int msg_idx; |
| 79 | unsigned int msg_ptr; |
| 80 | unsigned int irq; |
| 81 | |
| 82 | enum nuc900_i2c_state state; |
| 83 | |
| 84 | void __iomem *regs; |
| 85 | struct clk *clk; |
| 86 | struct device *dev; |
| 87 | struct resource *ioarea; |
| 88 | struct i2c_adapter adap; |
| 89 | }; |
| 90 | |
| 91 | /* nuc900_i2c_master_complete |
| 92 | * |
| 93 | * complete the message and wake up the caller, using the given return code, |
| 94 | * or zero to mean ok. |
| 95 | */ |
| 96 | |
| 97 | static inline void nuc900_i2c_master_complete(struct nuc900_i2c *i2c, int ret) |
| 98 | { |
| 99 | dev_dbg(i2c->dev, "master_complete %d\n", ret); |
| 100 | |
| 101 | i2c->msg_ptr = 0; |
| 102 | i2c->msg = NULL; |
| 103 | i2c->msg_idx++; |
| 104 | i2c->msg_num = 0; |
| 105 | if (ret) |
| 106 | i2c->msg_idx = ret; |
| 107 | |
| 108 | wake_up(&i2c->wait); |
| 109 | } |
| 110 | |
| 111 | /* irq enable/disable functions */ |
| 112 | |
| 113 | static inline void nuc900_i2c_disable_irq(struct nuc900_i2c *i2c) |
| 114 | { |
| 115 | unsigned long tmp; |
| 116 | |
| 117 | tmp = readl(i2c->regs + CSR); |
| 118 | writel(tmp & ~IRQEN, i2c->regs + CSR); |
| 119 | } |
| 120 | |
| 121 | static inline void nuc900_i2c_enable_irq(struct nuc900_i2c *i2c) |
| 122 | { |
| 123 | unsigned long tmp; |
| 124 | |
| 125 | tmp = readl(i2c->regs + CSR); |
| 126 | writel(tmp | IRQEN, i2c->regs + CSR); |
| 127 | } |
| 128 | |
| 129 | |
| 130 | /* nuc900_i2c_message_start |
| 131 | * |
| 132 | * put the start of a message onto the bus |
| 133 | */ |
| 134 | |
| 135 | static void nuc900_i2c_message_start(struct nuc900_i2c *i2c, |
| 136 | struct i2c_msg *msg) |
| 137 | { |
| 138 | unsigned int addr = (msg->addr & 0x7f) << 1; |
| 139 | |
| 140 | if (msg->flags & I2C_M_RD) |
| 141 | addr |= 0x1; |
| 142 | writel(addr & 0xff, i2c->regs + TXR); |
| 143 | writel(I2C_CMD_START | I2C_CMD_WRITE, i2c->regs + CMDR); |
| 144 | } |
| 145 | |
| 146 | static inline void nuc900_i2c_stop(struct nuc900_i2c *i2c, int ret) |
| 147 | { |
| 148 | |
| 149 | dev_dbg(i2c->dev, "STOP\n"); |
| 150 | |
| 151 | /* stop the transfer */ |
| 152 | i2c->state = STATE_STOP; |
| 153 | writel(I2C_CMD_STOP, i2c->regs + CMDR); |
| 154 | |
| 155 | nuc900_i2c_master_complete(i2c, ret); |
| 156 | nuc900_i2c_disable_irq(i2c); |
| 157 | } |
| 158 | |
| 159 | /* helper functions to determine the current state in the set of |
| 160 | * messages we are sending |
| 161 | */ |
| 162 | |
| 163 | /* is_lastmsg() |
| 164 | * |
| 165 | * returns TRUE if the current message is the last in the set |
| 166 | */ |
| 167 | |
| 168 | static inline int is_lastmsg(struct nuc900_i2c *i2c) |
| 169 | { |
| 170 | return i2c->msg_idx >= (i2c->msg_num - 1); |
| 171 | } |
| 172 | |
| 173 | /* is_msglast |
| 174 | * |
| 175 | * returns TRUE if we this is the last byte in the current message |
| 176 | */ |
| 177 | |
| 178 | static inline int is_msglast(struct nuc900_i2c *i2c) |
| 179 | { |
| 180 | return i2c->msg_ptr == i2c->msg->len-1; |
| 181 | } |
| 182 | |
| 183 | /* is_msgend |
| 184 | * |
| 185 | * returns TRUE if we reached the end of the current message |
| 186 | */ |
| 187 | |
| 188 | static inline int is_msgend(struct nuc900_i2c *i2c) |
| 189 | { |
| 190 | return i2c->msg_ptr >= i2c->msg->len; |
| 191 | } |
| 192 | |
| 193 | /* i2c_nuc900_irq_nextbyte |
| 194 | * |
| 195 | * process an interrupt and work out what to do |
| 196 | */ |
| 197 | |
| 198 | static void i2c_nuc900_irq_nextbyte(struct nuc900_i2c *i2c, |
| 199 | unsigned long iicstat) |
| 200 | { |
| 201 | unsigned char byte; |
| 202 | |
| 203 | switch (i2c->state) { |
| 204 | |
| 205 | case STATE_IDLE: |
| 206 | dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__); |
| 207 | break; |
| 208 | |
| 209 | case STATE_STOP: |
| 210 | dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__); |
| 211 | nuc900_i2c_disable_irq(i2c); |
| 212 | break; |
| 213 | |
| 214 | case STATE_START: |
| 215 | /* last thing we did was send a start condition on the |
| 216 | * bus, or started a new i2c message |
| 217 | */ |
| 218 | |
| 219 | if (iicstat & SLAVE_ACK && |
| 220 | !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { |
| 221 | /* ack was not received... */ |
| 222 | |
| 223 | dev_dbg(i2c->dev, "ack was not received\n"); |
| 224 | nuc900_i2c_stop(i2c, -ENXIO); |
| 225 | break; |
| 226 | } |
| 227 | |
| 228 | if (i2c->msg->flags & I2C_M_RD) |
| 229 | i2c->state = STATE_READ; |
| 230 | else |
| 231 | i2c->state = STATE_WRITE; |
| 232 | |
| 233 | /* terminate the transfer if there is nothing to do |
| 234 | * as this is used by the i2c probe to find devices. |
| 235 | */ |
| 236 | |
| 237 | if (is_lastmsg(i2c) && i2c->msg->len == 0) { |
| 238 | nuc900_i2c_stop(i2c, 0); |
| 239 | break; |
| 240 | } |
| 241 | |
| 242 | if (i2c->state == STATE_READ) |
| 243 | goto prepare_read; |
| 244 | |
| 245 | /* fall through to the write state, as we will need to |
| 246 | * send a byte as well |
| 247 | */ |
| 248 | |
| 249 | case STATE_WRITE: |
| 250 | /* we are writing data to the device... check for the |
| 251 | * end of the message, and if so, work out what to do |
| 252 | */ |
| 253 | |
| 254 | if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) { |
| 255 | if (iicstat & SLAVE_ACK) { |
| 256 | dev_dbg(i2c->dev, "WRITE: No Ack\n"); |
| 257 | |
| 258 | nuc900_i2c_stop(i2c, -ECONNREFUSED); |
| 259 | break; |
| 260 | } |
| 261 | } |
| 262 | |
| 263 | retry_write: |
| 264 | |
| 265 | if (!is_msgend(i2c)) { |
| 266 | byte = i2c->msg->buf[i2c->msg_ptr++]; |
| 267 | writeb(byte, i2c->regs + TXR); |
| 268 | writel(I2C_CMD_WRITE, i2c->regs + CMDR); |
| 269 | |
| 270 | } else if (!is_lastmsg(i2c)) { |
| 271 | /* we need to go to the next i2c message */ |
| 272 | |
| 273 | dev_dbg(i2c->dev, "WRITE: Next Message\n"); |
| 274 | |
| 275 | i2c->msg_ptr = 0; |
| 276 | i2c->msg_idx++; |
| 277 | i2c->msg++; |
| 278 | |
| 279 | /* check to see if we need to do another message */ |
| 280 | if (i2c->msg->flags & I2C_M_NOSTART) { |
| 281 | |
| 282 | if (i2c->msg->flags & I2C_M_RD) { |
| 283 | /* cannot do this, the controller |
| 284 | * forces us to send a new START |
| 285 | * when we change direction |
| 286 | */ |
| 287 | |
| 288 | nuc900_i2c_stop(i2c, -EINVAL); |
| 289 | } |
| 290 | |
| 291 | goto retry_write; |
| 292 | } else { |
| 293 | /* send the new start */ |
| 294 | nuc900_i2c_message_start(i2c, i2c->msg); |
| 295 | i2c->state = STATE_START; |
| 296 | } |
| 297 | |
| 298 | } else { |
| 299 | /* send stop */ |
| 300 | |
| 301 | nuc900_i2c_stop(i2c, 0); |
| 302 | } |
| 303 | break; |
| 304 | |
| 305 | case STATE_READ: |
| 306 | /* we have a byte of data in the data register, do |
Adam Buchbinder | 48fc7f7 | 2012-09-19 21:48:00 -0400 | [diff] [blame] | 307 | * something with it, and then work out whether we are |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 308 | * going to do any more read/write |
| 309 | */ |
| 310 | |
| 311 | byte = readb(i2c->regs + RXR); |
| 312 | i2c->msg->buf[i2c->msg_ptr++] = byte; |
| 313 | |
| 314 | prepare_read: |
| 315 | if (is_msglast(i2c)) { |
| 316 | /* last byte of buffer */ |
| 317 | |
| 318 | if (is_lastmsg(i2c)) |
| 319 | writel(I2C_CMD_READ | I2C_CMD_NACK, |
| 320 | i2c->regs + CMDR); |
| 321 | |
| 322 | } else if (is_msgend(i2c)) { |
| 323 | /* ok, we've read the entire buffer, see if there |
| 324 | * is anything else we need to do |
| 325 | */ |
| 326 | |
| 327 | if (is_lastmsg(i2c)) { |
| 328 | /* last message, send stop and complete */ |
| 329 | dev_dbg(i2c->dev, "READ: Send Stop\n"); |
| 330 | |
| 331 | nuc900_i2c_stop(i2c, 0); |
| 332 | } else { |
| 333 | /* go to the next transfer */ |
| 334 | dev_dbg(i2c->dev, "READ: Next Transfer\n"); |
| 335 | |
| 336 | i2c->msg_ptr = 0; |
| 337 | i2c->msg_idx++; |
| 338 | i2c->msg++; |
| 339 | |
| 340 | writel(I2C_CMD_READ, i2c->regs + CMDR); |
| 341 | } |
| 342 | |
| 343 | } else { |
| 344 | writel(I2C_CMD_READ, i2c->regs + CMDR); |
| 345 | } |
| 346 | |
| 347 | break; |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | /* nuc900_i2c_irq |
| 352 | * |
| 353 | * top level IRQ servicing routine |
| 354 | */ |
| 355 | |
| 356 | static irqreturn_t nuc900_i2c_irq(int irqno, void *dev_id) |
| 357 | { |
| 358 | struct nuc900_i2c *i2c = dev_id; |
| 359 | unsigned long status; |
| 360 | |
| 361 | status = readl(i2c->regs + CSR); |
| 362 | writel(status | IRQFLAG, i2c->regs + CSR); |
| 363 | |
| 364 | if (status & ARBIT_LOST) { |
| 365 | /* deal with arbitration loss */ |
| 366 | dev_err(i2c->dev, "deal with arbitration loss\n"); |
| 367 | goto out; |
| 368 | } |
| 369 | |
| 370 | if (i2c->state == STATE_IDLE) { |
| 371 | dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n"); |
| 372 | goto out; |
| 373 | } |
| 374 | |
| 375 | /* pretty much this leaves us with the fact that we've |
| 376 | * transmitted or received whatever byte we last sent |
| 377 | */ |
| 378 | |
| 379 | i2c_nuc900_irq_nextbyte(i2c, status); |
| 380 | |
| 381 | out: |
| 382 | return IRQ_HANDLED; |
| 383 | } |
| 384 | |
| 385 | |
| 386 | /* nuc900_i2c_set_master |
| 387 | * |
| 388 | * get the i2c bus for a master transaction |
| 389 | */ |
| 390 | |
| 391 | static int nuc900_i2c_set_master(struct nuc900_i2c *i2c) |
| 392 | { |
| 393 | int timeout = 400; |
| 394 | |
| 395 | while (timeout-- > 0) { |
| 396 | if (((readl(i2c->regs + SWR) & I2CSTART) == I2CSTART) && |
| 397 | ((readl(i2c->regs + CSR) & I2CBUSY) == 0)) { |
| 398 | return 0; |
| 399 | } |
| 400 | |
| 401 | msleep(1); |
| 402 | } |
| 403 | |
| 404 | return -ETIMEDOUT; |
| 405 | } |
| 406 | |
| 407 | /* nuc900_i2c_doxfer |
| 408 | * |
| 409 | * this starts an i2c transfer |
| 410 | */ |
| 411 | |
| 412 | static int nuc900_i2c_doxfer(struct nuc900_i2c *i2c, |
| 413 | struct i2c_msg *msgs, int num) |
| 414 | { |
| 415 | unsigned long iicstat, timeout; |
| 416 | int spins = 20; |
| 417 | int ret; |
| 418 | |
| 419 | ret = nuc900_i2c_set_master(i2c); |
| 420 | if (ret != 0) { |
| 421 | dev_err(i2c->dev, "cannot get bus (error %d)\n", ret); |
| 422 | ret = -EAGAIN; |
| 423 | goto out; |
| 424 | } |
| 425 | |
| 426 | spin_lock_irq(&i2c->lock); |
| 427 | |
| 428 | i2c->msg = msgs; |
| 429 | i2c->msg_num = num; |
| 430 | i2c->msg_ptr = 0; |
| 431 | i2c->msg_idx = 0; |
| 432 | i2c->state = STATE_START; |
| 433 | |
| 434 | nuc900_i2c_message_start(i2c, msgs); |
| 435 | spin_unlock_irq(&i2c->lock); |
| 436 | |
| 437 | timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); |
| 438 | |
| 439 | ret = i2c->msg_idx; |
| 440 | |
| 441 | /* having these next two as dev_err() makes life very |
| 442 | * noisy when doing an i2cdetect |
| 443 | */ |
| 444 | |
| 445 | if (timeout == 0) |
| 446 | dev_dbg(i2c->dev, "timeout\n"); |
| 447 | else if (ret != num) |
| 448 | dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); |
| 449 | |
| 450 | /* ensure the stop has been through the bus */ |
| 451 | |
| 452 | dev_dbg(i2c->dev, "waiting for bus idle\n"); |
| 453 | |
| 454 | /* first, try busy waiting briefly */ |
| 455 | do { |
| 456 | iicstat = readl(i2c->regs + CSR); |
| 457 | } while ((iicstat & I2CBUSY) && --spins); |
| 458 | |
| 459 | /* if that timed out sleep */ |
| 460 | if (!spins) { |
| 461 | msleep(1); |
| 462 | iicstat = readl(i2c->regs + CSR); |
| 463 | } |
| 464 | |
| 465 | if (iicstat & I2CBUSY) |
| 466 | dev_warn(i2c->dev, "timeout waiting for bus idle\n"); |
| 467 | |
| 468 | out: |
| 469 | return ret; |
| 470 | } |
| 471 | |
| 472 | /* nuc900_i2c_xfer |
| 473 | * |
| 474 | * first port of call from the i2c bus code when an message needs |
| 475 | * transferring across the i2c bus. |
| 476 | */ |
| 477 | |
| 478 | static int nuc900_i2c_xfer(struct i2c_adapter *adap, |
| 479 | struct i2c_msg *msgs, int num) |
| 480 | { |
| 481 | struct nuc900_i2c *i2c = (struct nuc900_i2c *)adap->algo_data; |
| 482 | int retry; |
| 483 | int ret; |
| 484 | |
| 485 | nuc900_i2c_enable_irq(i2c); |
| 486 | |
| 487 | for (retry = 0; retry < adap->retries; retry++) { |
| 488 | |
| 489 | ret = nuc900_i2c_doxfer(i2c, msgs, num); |
| 490 | |
| 491 | if (ret != -EAGAIN) |
| 492 | return ret; |
| 493 | |
| 494 | dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); |
| 495 | |
| 496 | udelay(100); |
| 497 | } |
| 498 | |
| 499 | return -EREMOTEIO; |
| 500 | } |
| 501 | |
| 502 | /* declare our i2c functionality */ |
| 503 | static u32 nuc900_i2c_func(struct i2c_adapter *adap) |
| 504 | { |
Mark Brown | 14674e7 | 2012-05-30 10:55:34 +0200 | [diff] [blame] | 505 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART | |
| 506 | I2C_FUNC_PROTOCOL_MANGLING; |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 507 | } |
| 508 | |
| 509 | /* i2c bus registration info */ |
| 510 | |
| 511 | static const struct i2c_algorithm nuc900_i2c_algorithm = { |
| 512 | .master_xfer = nuc900_i2c_xfer, |
| 513 | .functionality = nuc900_i2c_func, |
| 514 | }; |
| 515 | |
| 516 | /* nuc900_i2c_probe |
| 517 | * |
| 518 | * called by the bus driver when a suitable device is found |
| 519 | */ |
| 520 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 521 | static int nuc900_i2c_probe(struct platform_device *pdev) |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 522 | { |
| 523 | struct nuc900_i2c *i2c; |
| 524 | struct nuc900_platform_i2c *pdata; |
| 525 | struct resource *res; |
| 526 | int ret; |
| 527 | |
| 528 | pdata = pdev->dev.platform_data; |
| 529 | if (!pdata) { |
| 530 | dev_err(&pdev->dev, "no platform data\n"); |
| 531 | return -EINVAL; |
| 532 | } |
| 533 | |
| 534 | i2c = kzalloc(sizeof(struct nuc900_i2c), GFP_KERNEL); |
| 535 | if (!i2c) { |
| 536 | dev_err(&pdev->dev, "no memory for state\n"); |
| 537 | return -ENOMEM; |
| 538 | } |
| 539 | |
| 540 | strlcpy(i2c->adap.name, "nuc900-i2c0", sizeof(i2c->adap.name)); |
| 541 | i2c->adap.owner = THIS_MODULE; |
| 542 | i2c->adap.algo = &nuc900_i2c_algorithm; |
| 543 | i2c->adap.retries = 2; |
| 544 | i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; |
| 545 | |
| 546 | spin_lock_init(&i2c->lock); |
| 547 | init_waitqueue_head(&i2c->wait); |
| 548 | |
| 549 | /* find the clock and enable it */ |
| 550 | |
| 551 | i2c->dev = &pdev->dev; |
| 552 | i2c->clk = clk_get(&pdev->dev, NULL); |
| 553 | if (IS_ERR(i2c->clk)) { |
| 554 | dev_err(&pdev->dev, "cannot get clock\n"); |
| 555 | ret = -ENOENT; |
| 556 | goto err_noclk; |
| 557 | } |
| 558 | |
| 559 | dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); |
| 560 | |
| 561 | clk_enable(i2c->clk); |
| 562 | |
| 563 | /* map the registers */ |
| 564 | |
| 565 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 566 | if (res == NULL) { |
| 567 | dev_err(&pdev->dev, "cannot find IO resource\n"); |
| 568 | ret = -ENOENT; |
| 569 | goto err_clk; |
| 570 | } |
| 571 | |
| 572 | i2c->ioarea = request_mem_region(res->start, resource_size(res), |
| 573 | pdev->name); |
| 574 | |
| 575 | if (i2c->ioarea == NULL) { |
| 576 | dev_err(&pdev->dev, "cannot request IO\n"); |
| 577 | ret = -ENXIO; |
| 578 | goto err_clk; |
| 579 | } |
| 580 | |
| 581 | i2c->regs = ioremap(res->start, resource_size(res)); |
| 582 | |
| 583 | if (i2c->regs == NULL) { |
| 584 | dev_err(&pdev->dev, "cannot map IO\n"); |
| 585 | ret = -ENXIO; |
| 586 | goto err_ioarea; |
| 587 | } |
| 588 | |
| 589 | dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", |
| 590 | i2c->regs, i2c->ioarea, res); |
| 591 | |
| 592 | /* setup info block for the i2c core */ |
| 593 | |
| 594 | i2c->adap.algo_data = i2c; |
| 595 | i2c->adap.dev.parent = &pdev->dev; |
| 596 | |
Axel Lin | 97371fa | 2011-11-25 00:23:28 +0100 | [diff] [blame] | 597 | mfp_set_groupg(&pdev->dev, NULL); |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 598 | |
| 599 | clk_get_rate(i2c->clk); |
| 600 | |
| 601 | ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1; |
| 602 | writel(ret & 0xffff, i2c->regs + DIVIDER); |
| 603 | |
| 604 | /* find the IRQ for this unit (note, this relies on the init call to |
| 605 | * ensure no current IRQs pending |
| 606 | */ |
| 607 | |
| 608 | i2c->irq = ret = platform_get_irq(pdev, 0); |
| 609 | if (ret <= 0) { |
| 610 | dev_err(&pdev->dev, "cannot find IRQ\n"); |
| 611 | goto err_iomap; |
| 612 | } |
| 613 | |
Yong Zhang | 4311051 | 2011-09-21 17:28:33 +0800 | [diff] [blame] | 614 | ret = request_irq(i2c->irq, nuc900_i2c_irq, IRQF_SHARED, |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 615 | dev_name(&pdev->dev), i2c); |
| 616 | |
| 617 | if (ret != 0) { |
| 618 | dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); |
| 619 | goto err_iomap; |
| 620 | } |
| 621 | |
| 622 | /* Note, previous versions of the driver used i2c_add_adapter() |
| 623 | * to add the bus at any number. We now pass the bus number via |
| 624 | * the platform data, so if unset it will now default to always |
| 625 | * being bus 0. |
| 626 | */ |
| 627 | |
| 628 | i2c->adap.nr = pdata->bus_num; |
| 629 | |
| 630 | ret = i2c_add_numbered_adapter(&i2c->adap); |
| 631 | if (ret < 0) { |
| 632 | dev_err(&pdev->dev, "failed to add bus to i2c core\n"); |
| 633 | goto err_irq; |
| 634 | } |
| 635 | |
| 636 | platform_set_drvdata(pdev, i2c); |
| 637 | |
| 638 | dev_info(&pdev->dev, "%s: NUC900 I2C adapter\n", |
| 639 | dev_name(&i2c->adap.dev)); |
| 640 | return 0; |
| 641 | |
| 642 | err_irq: |
| 643 | free_irq(i2c->irq, i2c); |
| 644 | |
| 645 | err_iomap: |
| 646 | iounmap(i2c->regs); |
| 647 | |
| 648 | err_ioarea: |
| 649 | release_resource(i2c->ioarea); |
| 650 | kfree(i2c->ioarea); |
| 651 | |
| 652 | err_clk: |
| 653 | clk_disable(i2c->clk); |
| 654 | clk_put(i2c->clk); |
| 655 | |
| 656 | err_noclk: |
| 657 | kfree(i2c); |
| 658 | return ret; |
| 659 | } |
| 660 | |
| 661 | /* nuc900_i2c_remove |
| 662 | * |
| 663 | * called when device is removed from the bus |
| 664 | */ |
| 665 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 666 | static int nuc900_i2c_remove(struct platform_device *pdev) |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 667 | { |
| 668 | struct nuc900_i2c *i2c = platform_get_drvdata(pdev); |
| 669 | |
| 670 | i2c_del_adapter(&i2c->adap); |
| 671 | free_irq(i2c->irq, i2c); |
| 672 | |
| 673 | clk_disable(i2c->clk); |
| 674 | clk_put(i2c->clk); |
| 675 | |
| 676 | iounmap(i2c->regs); |
| 677 | |
| 678 | release_resource(i2c->ioarea); |
| 679 | kfree(i2c->ioarea); |
| 680 | kfree(i2c); |
| 681 | |
| 682 | return 0; |
| 683 | } |
| 684 | |
| 685 | static struct platform_driver nuc900_i2c_driver = { |
| 686 | .probe = nuc900_i2c_probe, |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 687 | .remove = nuc900_i2c_remove, |
Wan ZongShun | ededad3 | 2010-06-25 13:43:07 +0800 | [diff] [blame] | 688 | .driver = { |
| 689 | .owner = THIS_MODULE, |
| 690 | .name = "nuc900-i2c0", |
| 691 | }, |
| 692 | }; |
| 693 | |
| 694 | static int __init i2c_adap_nuc900_init(void) |
| 695 | { |
| 696 | return platform_driver_register(&nuc900_i2c_driver); |
| 697 | } |
| 698 | |
| 699 | static void __exit i2c_adap_nuc900_exit(void) |
| 700 | { |
| 701 | platform_driver_unregister(&nuc900_i2c_driver); |
| 702 | } |
| 703 | subsys_initcall(i2c_adap_nuc900_init); |
| 704 | module_exit(i2c_adap_nuc900_exit); |
| 705 | |
| 706 | MODULE_DESCRIPTION("NUC900 I2C Bus driver"); |
| 707 | MODULE_AUTHOR("Wan ZongShun, <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>"); |
| 708 | MODULE_LICENSE("GPL"); |
| 709 | MODULE_ALIAS("platform:nuc900-i2c0"); |