Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* linux/drivers/i2c/busses/i2c-s3c2410.c |
| 2 | * |
| 3 | * Copyright (C) 2004,2005 Simtec Electronics |
| 4 | * Ben Dooks <ben@simtec.co.uk> |
| 5 | * |
| 6 | * S3C2410 I2C Controller |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | */ |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/kernel.h> |
| 24 | #include <linux/module.h> |
| 25 | |
| 26 | #include <linux/i2c.h> |
| 27 | #include <linux/i2c-id.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/time.h> |
| 30 | #include <linux/interrupt.h> |
| 31 | #include <linux/sched.h> |
| 32 | #include <linux/delay.h> |
| 33 | #include <linux/errno.h> |
| 34 | #include <linux/err.h> |
Russell King | d052d1b | 2005-10-29 19:07:23 +0100 | [diff] [blame] | 35 | #include <linux/platform_device.h> |
Russell King | f8ce254 | 2006-01-07 16:15:52 +0000 | [diff] [blame] | 36 | #include <linux/clk.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
| 38 | #include <asm/hardware.h> |
| 39 | #include <asm/irq.h> |
| 40 | #include <asm/io.h> |
| 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #include <asm/arch/regs-gpio.h> |
| 43 | #include <asm/arch/regs-iic.h> |
| 44 | #include <asm/arch/iic.h> |
| 45 | |
| 46 | /* i2c controller state */ |
| 47 | |
| 48 | enum s3c24xx_i2c_state { |
| 49 | STATE_IDLE, |
| 50 | STATE_START, |
| 51 | STATE_READ, |
| 52 | STATE_WRITE, |
| 53 | STATE_STOP |
| 54 | }; |
| 55 | |
| 56 | struct s3c24xx_i2c { |
| 57 | spinlock_t lock; |
| 58 | wait_queue_head_t wait; |
| 59 | |
| 60 | struct i2c_msg *msg; |
| 61 | unsigned int msg_num; |
| 62 | unsigned int msg_idx; |
| 63 | unsigned int msg_ptr; |
| 64 | |
| 65 | enum s3c24xx_i2c_state state; |
| 66 | |
| 67 | void __iomem *regs; |
| 68 | struct clk *clk; |
| 69 | struct device *dev; |
| 70 | struct resource *irq; |
| 71 | struct resource *ioarea; |
| 72 | struct i2c_adapter adap; |
| 73 | }; |
| 74 | |
| 75 | /* default platform data to use if not supplied in the platform_device |
| 76 | */ |
| 77 | |
| 78 | static struct s3c2410_platform_i2c s3c24xx_i2c_default_platform = { |
| 79 | .flags = 0, |
| 80 | .slave_addr = 0x10, |
| 81 | .bus_freq = 100*1000, |
| 82 | .max_freq = 400*1000, |
| 83 | .sda_delay = S3C2410_IICLC_SDA_DELAY5 | S3C2410_IICLC_FILTER_ON, |
| 84 | }; |
| 85 | |
| 86 | /* s3c24xx_i2c_is2440() |
| 87 | * |
| 88 | * return true is this is an s3c2440 |
| 89 | */ |
| 90 | |
| 91 | static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c) |
| 92 | { |
| 93 | struct platform_device *pdev = to_platform_device(i2c->dev); |
| 94 | |
| 95 | return !strcmp(pdev->name, "s3c2440-i2c"); |
| 96 | } |
| 97 | |
| 98 | |
| 99 | /* s3c24xx_i2c_get_platformdata |
| 100 | * |
| 101 | * get the platform data associated with the given device, or return |
| 102 | * the default if there is none |
| 103 | */ |
| 104 | |
| 105 | static inline struct s3c2410_platform_i2c *s3c24xx_i2c_get_platformdata(struct device *dev) |
| 106 | { |
| 107 | if (dev->platform_data != NULL) |
| 108 | return (struct s3c2410_platform_i2c *)dev->platform_data; |
| 109 | |
| 110 | return &s3c24xx_i2c_default_platform; |
| 111 | } |
| 112 | |
| 113 | /* s3c24xx_i2c_master_complete |
| 114 | * |
| 115 | * complete the message and wake up the caller, using the given return code, |
| 116 | * or zero to mean ok. |
| 117 | */ |
| 118 | |
| 119 | static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret) |
| 120 | { |
| 121 | dev_dbg(i2c->dev, "master_complete %d\n", ret); |
| 122 | |
| 123 | i2c->msg_ptr = 0; |
| 124 | i2c->msg = NULL; |
| 125 | i2c->msg_idx ++; |
| 126 | i2c->msg_num = 0; |
| 127 | if (ret) |
| 128 | i2c->msg_idx = ret; |
| 129 | |
| 130 | wake_up(&i2c->wait); |
| 131 | } |
| 132 | |
| 133 | static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c) |
| 134 | { |
| 135 | unsigned long tmp; |
| 136 | |
| 137 | tmp = readl(i2c->regs + S3C2410_IICCON); |
| 138 | writel(tmp & ~S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON); |
| 139 | |
| 140 | } |
| 141 | |
| 142 | static inline void s3c24xx_i2c_enable_ack(struct s3c24xx_i2c *i2c) |
| 143 | { |
| 144 | unsigned long tmp; |
| 145 | |
| 146 | tmp = readl(i2c->regs + S3C2410_IICCON); |
| 147 | writel(tmp | S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON); |
| 148 | |
| 149 | } |
| 150 | |
| 151 | /* irq enable/disable functions */ |
| 152 | |
| 153 | static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c) |
| 154 | { |
| 155 | unsigned long tmp; |
| 156 | |
| 157 | tmp = readl(i2c->regs + S3C2410_IICCON); |
| 158 | writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON); |
| 159 | } |
| 160 | |
| 161 | static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c) |
| 162 | { |
| 163 | unsigned long tmp; |
| 164 | |
| 165 | tmp = readl(i2c->regs + S3C2410_IICCON); |
| 166 | writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON); |
| 167 | } |
| 168 | |
| 169 | |
| 170 | /* s3c24xx_i2c_message_start |
| 171 | * |
| 172 | * put the start of a message onto the bus |
| 173 | */ |
| 174 | |
| 175 | static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c, |
| 176 | struct i2c_msg *msg) |
| 177 | { |
| 178 | unsigned int addr = (msg->addr & 0x7f) << 1; |
| 179 | unsigned long stat; |
| 180 | unsigned long iiccon; |
| 181 | |
| 182 | stat = 0; |
| 183 | stat |= S3C2410_IICSTAT_TXRXEN; |
| 184 | |
| 185 | if (msg->flags & I2C_M_RD) { |
| 186 | stat |= S3C2410_IICSTAT_MASTER_RX; |
| 187 | addr |= 1; |
| 188 | } else |
| 189 | stat |= S3C2410_IICSTAT_MASTER_TX; |
| 190 | |
| 191 | if (msg->flags & I2C_M_REV_DIR_ADDR) |
| 192 | addr ^= 1; |
| 193 | |
| 194 | // todo - check for wether ack wanted or not |
| 195 | s3c24xx_i2c_enable_ack(i2c); |
| 196 | |
| 197 | iiccon = readl(i2c->regs + S3C2410_IICCON); |
| 198 | writel(stat, i2c->regs + S3C2410_IICSTAT); |
| 199 | |
| 200 | dev_dbg(i2c->dev, "START: %08lx to IICSTAT, %02x to DS\n", stat, addr); |
| 201 | writeb(addr, i2c->regs + S3C2410_IICDS); |
| 202 | |
| 203 | // delay a bit and reset iiccon before setting start (per samsung) |
| 204 | udelay(1); |
| 205 | dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon); |
| 206 | writel(iiccon, i2c->regs + S3C2410_IICCON); |
| 207 | |
| 208 | stat |= S3C2410_IICSTAT_START; |
| 209 | writel(stat, i2c->regs + S3C2410_IICSTAT); |
| 210 | } |
| 211 | |
| 212 | static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret) |
| 213 | { |
| 214 | unsigned long iicstat = readl(i2c->regs + S3C2410_IICSTAT); |
| 215 | |
| 216 | dev_dbg(i2c->dev, "STOP\n"); |
| 217 | |
| 218 | /* stop the transfer */ |
| 219 | iicstat &= ~ S3C2410_IICSTAT_START; |
| 220 | writel(iicstat, i2c->regs + S3C2410_IICSTAT); |
| 221 | |
| 222 | i2c->state = STATE_STOP; |
| 223 | |
| 224 | s3c24xx_i2c_master_complete(i2c, ret); |
| 225 | s3c24xx_i2c_disable_irq(i2c); |
| 226 | } |
| 227 | |
| 228 | /* helper functions to determine the current state in the set of |
| 229 | * messages we are sending */ |
| 230 | |
| 231 | /* is_lastmsg() |
| 232 | * |
| 233 | * returns TRUE if the current message is the last in the set |
| 234 | */ |
| 235 | |
| 236 | static inline int is_lastmsg(struct s3c24xx_i2c *i2c) |
| 237 | { |
| 238 | return i2c->msg_idx >= (i2c->msg_num - 1); |
| 239 | } |
| 240 | |
| 241 | /* is_msglast |
| 242 | * |
| 243 | * returns TRUE if we this is the last byte in the current message |
| 244 | */ |
| 245 | |
| 246 | static inline int is_msglast(struct s3c24xx_i2c *i2c) |
| 247 | { |
| 248 | return i2c->msg_ptr == i2c->msg->len-1; |
| 249 | } |
| 250 | |
| 251 | /* is_msgend |
| 252 | * |
| 253 | * returns TRUE if we reached the end of the current message |
| 254 | */ |
| 255 | |
| 256 | static inline int is_msgend(struct s3c24xx_i2c *i2c) |
| 257 | { |
| 258 | return i2c->msg_ptr >= i2c->msg->len; |
| 259 | } |
| 260 | |
| 261 | /* i2s_s3c_irq_nextbyte |
| 262 | * |
| 263 | * process an interrupt and work out what to do |
| 264 | */ |
| 265 | |
| 266 | static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) |
| 267 | { |
| 268 | unsigned long tmp; |
| 269 | unsigned char byte; |
| 270 | int ret = 0; |
| 271 | |
| 272 | switch (i2c->state) { |
| 273 | |
| 274 | case STATE_IDLE: |
| 275 | dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __FUNCTION__); |
| 276 | goto out; |
| 277 | break; |
| 278 | |
| 279 | case STATE_STOP: |
| 280 | dev_err(i2c->dev, "%s: called in STATE_STOP\n", __FUNCTION__); |
| 281 | s3c24xx_i2c_disable_irq(i2c); |
| 282 | goto out_ack; |
| 283 | |
| 284 | case STATE_START: |
| 285 | /* last thing we did was send a start condition on the |
| 286 | * bus, or started a new i2c message |
| 287 | */ |
| 288 | |
| 289 | if (iicstat & S3C2410_IICSTAT_LASTBIT && |
| 290 | !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { |
| 291 | /* ack was not received... */ |
| 292 | |
| 293 | dev_dbg(i2c->dev, "ack was not received\n"); |
| 294 | s3c24xx_i2c_stop(i2c, -EREMOTEIO); |
| 295 | goto out_ack; |
| 296 | } |
| 297 | |
| 298 | if (i2c->msg->flags & I2C_M_RD) |
| 299 | i2c->state = STATE_READ; |
| 300 | else |
| 301 | i2c->state = STATE_WRITE; |
| 302 | |
| 303 | /* terminate the transfer if there is nothing to do |
| 304 | * (used by the i2c probe to find devices */ |
| 305 | |
| 306 | if (is_lastmsg(i2c) && i2c->msg->len == 0) { |
| 307 | s3c24xx_i2c_stop(i2c, 0); |
| 308 | goto out_ack; |
| 309 | } |
| 310 | |
| 311 | if (i2c->state == STATE_READ) |
| 312 | goto prepare_read; |
| 313 | |
| 314 | /* fall through to the write state, as we will need to |
| 315 | * send a byte as well */ |
| 316 | |
| 317 | case STATE_WRITE: |
| 318 | /* we are writing data to the device... check for the |
| 319 | * end of the message, and if so, work out what to do |
| 320 | */ |
| 321 | |
| 322 | retry_write: |
| 323 | if (!is_msgend(i2c)) { |
| 324 | byte = i2c->msg->buf[i2c->msg_ptr++]; |
| 325 | writeb(byte, i2c->regs + S3C2410_IICDS); |
| 326 | |
| 327 | } else if (!is_lastmsg(i2c)) { |
| 328 | /* we need to go to the next i2c message */ |
| 329 | |
| 330 | dev_dbg(i2c->dev, "WRITE: Next Message\n"); |
| 331 | |
| 332 | i2c->msg_ptr = 0; |
| 333 | i2c->msg_idx ++; |
| 334 | i2c->msg++; |
| 335 | |
| 336 | /* check to see if we need to do another message */ |
| 337 | if (i2c->msg->flags & I2C_M_NOSTART) { |
| 338 | |
| 339 | if (i2c->msg->flags & I2C_M_RD) { |
| 340 | /* cannot do this, the controller |
| 341 | * forces us to send a new START |
| 342 | * when we change direction */ |
| 343 | |
| 344 | s3c24xx_i2c_stop(i2c, -EINVAL); |
| 345 | } |
| 346 | |
| 347 | goto retry_write; |
| 348 | } else { |
| 349 | |
| 350 | /* send the new start */ |
| 351 | s3c24xx_i2c_message_start(i2c, i2c->msg); |
| 352 | i2c->state = STATE_START; |
| 353 | } |
| 354 | |
| 355 | } else { |
| 356 | /* send stop */ |
| 357 | |
| 358 | s3c24xx_i2c_stop(i2c, 0); |
| 359 | } |
| 360 | break; |
| 361 | |
| 362 | case STATE_READ: |
| 363 | /* we have a byte of data in the data register, do |
| 364 | * something with it, and then work out wether we are |
| 365 | * going to do any more read/write |
| 366 | */ |
| 367 | |
| 368 | if (!(i2c->msg->flags & I2C_M_IGNORE_NAK) && |
| 369 | !(is_msglast(i2c) && is_lastmsg(i2c))) { |
| 370 | |
| 371 | if (iicstat & S3C2410_IICSTAT_LASTBIT) { |
| 372 | dev_dbg(i2c->dev, "READ: No Ack\n"); |
| 373 | |
| 374 | s3c24xx_i2c_stop(i2c, -ECONNREFUSED); |
| 375 | goto out_ack; |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | byte = readb(i2c->regs + S3C2410_IICDS); |
| 380 | i2c->msg->buf[i2c->msg_ptr++] = byte; |
| 381 | |
| 382 | prepare_read: |
| 383 | if (is_msglast(i2c)) { |
| 384 | /* last byte of buffer */ |
| 385 | |
| 386 | if (is_lastmsg(i2c)) |
| 387 | s3c24xx_i2c_disable_ack(i2c); |
| 388 | |
| 389 | } else if (is_msgend(i2c)) { |
| 390 | /* ok, we've read the entire buffer, see if there |
| 391 | * is anything else we need to do */ |
| 392 | |
| 393 | if (is_lastmsg(i2c)) { |
| 394 | /* last message, send stop and complete */ |
| 395 | dev_dbg(i2c->dev, "READ: Send Stop\n"); |
| 396 | |
| 397 | s3c24xx_i2c_stop(i2c, 0); |
| 398 | } else { |
| 399 | /* go to the next transfer */ |
| 400 | dev_dbg(i2c->dev, "READ: Next Transfer\n"); |
| 401 | |
| 402 | i2c->msg_ptr = 0; |
| 403 | i2c->msg_idx++; |
| 404 | i2c->msg++; |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | break; |
| 409 | } |
| 410 | |
| 411 | /* acknowlegde the IRQ and get back on with the work */ |
| 412 | |
| 413 | out_ack: |
| 414 | tmp = readl(i2c->regs + S3C2410_IICCON); |
| 415 | tmp &= ~S3C2410_IICCON_IRQPEND; |
| 416 | writel(tmp, i2c->regs + S3C2410_IICCON); |
| 417 | out: |
| 418 | return ret; |
| 419 | } |
| 420 | |
| 421 | /* s3c24xx_i2c_irq |
| 422 | * |
| 423 | * top level IRQ servicing routine |
| 424 | */ |
| 425 | |
| 426 | static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id, |
| 427 | struct pt_regs *regs) |
| 428 | { |
| 429 | struct s3c24xx_i2c *i2c = dev_id; |
| 430 | unsigned long status; |
| 431 | unsigned long tmp; |
| 432 | |
| 433 | status = readl(i2c->regs + S3C2410_IICSTAT); |
| 434 | |
| 435 | if (status & S3C2410_IICSTAT_ARBITR) { |
| 436 | // deal with arbitration loss |
| 437 | dev_err(i2c->dev, "deal with arbitration loss\n"); |
| 438 | } |
| 439 | |
| 440 | if (i2c->state == STATE_IDLE) { |
| 441 | dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n"); |
| 442 | |
| 443 | tmp = readl(i2c->regs + S3C2410_IICCON); |
| 444 | tmp &= ~S3C2410_IICCON_IRQPEND; |
| 445 | writel(tmp, i2c->regs + S3C2410_IICCON); |
| 446 | goto out; |
| 447 | } |
| 448 | |
| 449 | /* pretty much this leaves us with the fact that we've |
| 450 | * transmitted or received whatever byte we last sent */ |
| 451 | |
| 452 | i2s_s3c_irq_nextbyte(i2c, status); |
| 453 | |
| 454 | out: |
| 455 | return IRQ_HANDLED; |
| 456 | } |
| 457 | |
| 458 | |
| 459 | /* s3c24xx_i2c_set_master |
| 460 | * |
| 461 | * get the i2c bus for a master transaction |
| 462 | */ |
| 463 | |
| 464 | static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c) |
| 465 | { |
| 466 | unsigned long iicstat; |
| 467 | int timeout = 400; |
| 468 | |
| 469 | while (timeout-- > 0) { |
| 470 | iicstat = readl(i2c->regs + S3C2410_IICSTAT); |
| 471 | |
| 472 | if (!(iicstat & S3C2410_IICSTAT_BUSBUSY)) |
| 473 | return 0; |
| 474 | |
| 475 | msleep(1); |
| 476 | } |
| 477 | |
| 478 | dev_dbg(i2c->dev, "timeout: GPEDAT is %08x\n", |
| 479 | __raw_readl(S3C2410_GPEDAT)); |
| 480 | |
| 481 | return -ETIMEDOUT; |
| 482 | } |
| 483 | |
| 484 | /* s3c24xx_i2c_doxfer |
| 485 | * |
| 486 | * this starts an i2c transfer |
| 487 | */ |
| 488 | |
| 489 | static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num) |
| 490 | { |
| 491 | unsigned long timeout; |
| 492 | int ret; |
| 493 | |
| 494 | ret = s3c24xx_i2c_set_master(i2c); |
| 495 | if (ret != 0) { |
| 496 | dev_err(i2c->dev, "cannot get bus (error %d)\n", ret); |
| 497 | ret = -EAGAIN; |
| 498 | goto out; |
| 499 | } |
| 500 | |
| 501 | spin_lock_irq(&i2c->lock); |
| 502 | |
| 503 | i2c->msg = msgs; |
| 504 | i2c->msg_num = num; |
| 505 | i2c->msg_ptr = 0; |
| 506 | i2c->msg_idx = 0; |
| 507 | i2c->state = STATE_START; |
| 508 | |
| 509 | s3c24xx_i2c_enable_irq(i2c); |
| 510 | s3c24xx_i2c_message_start(i2c, msgs); |
| 511 | spin_unlock_irq(&i2c->lock); |
| 512 | |
| 513 | timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); |
| 514 | |
| 515 | ret = i2c->msg_idx; |
| 516 | |
| 517 | /* having these next two as dev_err() makes life very |
| 518 | * noisy when doing an i2cdetect */ |
| 519 | |
| 520 | if (timeout == 0) |
| 521 | dev_dbg(i2c->dev, "timeout\n"); |
| 522 | else if (ret != num) |
| 523 | dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); |
| 524 | |
| 525 | /* ensure the stop has been through the bus */ |
| 526 | |
| 527 | msleep(1); |
| 528 | |
| 529 | out: |
| 530 | return ret; |
| 531 | } |
| 532 | |
| 533 | /* s3c24xx_i2c_xfer |
| 534 | * |
| 535 | * first port of call from the i2c bus code when an message needs |
Steven Cole | 44bbe87 | 2005-05-03 18:21:25 -0600 | [diff] [blame] | 536 | * transferring across the i2c bus. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | */ |
| 538 | |
| 539 | static int s3c24xx_i2c_xfer(struct i2c_adapter *adap, |
| 540 | struct i2c_msg *msgs, int num) |
| 541 | { |
| 542 | struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data; |
| 543 | int retry; |
| 544 | int ret; |
| 545 | |
| 546 | for (retry = 0; retry < adap->retries; retry++) { |
| 547 | |
| 548 | ret = s3c24xx_i2c_doxfer(i2c, msgs, num); |
| 549 | |
| 550 | if (ret != -EAGAIN) |
| 551 | return ret; |
| 552 | |
| 553 | dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); |
| 554 | |
| 555 | udelay(100); |
| 556 | } |
| 557 | |
| 558 | return -EREMOTEIO; |
| 559 | } |
| 560 | |
| 561 | /* declare our i2c functionality */ |
| 562 | static u32 s3c24xx_i2c_func(struct i2c_adapter *adap) |
| 563 | { |
| 564 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; |
| 565 | } |
| 566 | |
| 567 | /* i2c bus registration info */ |
| 568 | |
| 569 | static struct i2c_algorithm s3c24xx_i2c_algorithm = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | .master_xfer = s3c24xx_i2c_xfer, |
| 571 | .functionality = s3c24xx_i2c_func, |
| 572 | }; |
| 573 | |
| 574 | static struct s3c24xx_i2c s3c24xx_i2c = { |
| 575 | .lock = SPIN_LOCK_UNLOCKED, |
| 576 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER(s3c24xx_i2c.wait), |
| 577 | .adap = { |
| 578 | .name = "s3c2410-i2c", |
| 579 | .owner = THIS_MODULE, |
| 580 | .algo = &s3c24xx_i2c_algorithm, |
| 581 | .retries = 2, |
| 582 | .class = I2C_CLASS_HWMON, |
| 583 | }, |
| 584 | }; |
| 585 | |
| 586 | /* s3c24xx_i2c_calcdivisor |
| 587 | * |
| 588 | * return the divisor settings for a given frequency |
| 589 | */ |
| 590 | |
| 591 | static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted, |
| 592 | unsigned int *div1, unsigned int *divs) |
| 593 | { |
| 594 | unsigned int calc_divs = clkin / wanted; |
| 595 | unsigned int calc_div1; |
| 596 | |
| 597 | if (calc_divs > (16*16)) |
| 598 | calc_div1 = 512; |
| 599 | else |
| 600 | calc_div1 = 16; |
| 601 | |
| 602 | calc_divs += calc_div1-1; |
| 603 | calc_divs /= calc_div1; |
| 604 | |
| 605 | if (calc_divs == 0) |
| 606 | calc_divs = 1; |
| 607 | if (calc_divs > 17) |
| 608 | calc_divs = 17; |
| 609 | |
| 610 | *divs = calc_divs; |
| 611 | *div1 = calc_div1; |
| 612 | |
| 613 | return clkin / (calc_divs * calc_div1); |
| 614 | } |
| 615 | |
| 616 | /* freq_acceptable |
| 617 | * |
| 618 | * test wether a frequency is within the acceptable range of error |
| 619 | */ |
| 620 | |
| 621 | static inline int freq_acceptable(unsigned int freq, unsigned int wanted) |
| 622 | { |
| 623 | int diff = freq - wanted; |
| 624 | |
| 625 | return (diff >= -2 && diff <= 2); |
| 626 | } |
| 627 | |
| 628 | /* s3c24xx_i2c_getdivisor |
| 629 | * |
| 630 | * work out a divisor for the user requested frequency setting, |
| 631 | * either by the requested frequency, or scanning the acceptable |
| 632 | * range of frequencies until something is found |
| 633 | */ |
| 634 | |
| 635 | static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c, |
| 636 | struct s3c2410_platform_i2c *pdata, |
| 637 | unsigned long *iicon, |
| 638 | unsigned int *got) |
| 639 | { |
| 640 | unsigned long clkin = clk_get_rate(i2c->clk); |
| 641 | |
| 642 | unsigned int divs, div1; |
| 643 | int freq; |
| 644 | int start, end; |
| 645 | |
| 646 | clkin /= 1000; /* clkin now in KHz */ |
| 647 | |
| 648 | dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n", |
| 649 | pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq); |
| 650 | |
| 651 | if (pdata->bus_freq != 0) { |
| 652 | freq = s3c24xx_i2c_calcdivisor(clkin, pdata->bus_freq/1000, |
| 653 | &div1, &divs); |
| 654 | if (freq_acceptable(freq, pdata->bus_freq/1000)) |
| 655 | goto found; |
| 656 | } |
| 657 | |
| 658 | /* ok, we may have to search for something suitable... */ |
| 659 | |
| 660 | start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq; |
| 661 | end = pdata->min_freq; |
| 662 | |
| 663 | start /= 1000; |
| 664 | end /= 1000; |
| 665 | |
| 666 | /* search loop... */ |
| 667 | |
| 668 | for (; start > end; start--) { |
| 669 | freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs); |
| 670 | if (freq_acceptable(freq, start)) |
| 671 | goto found; |
| 672 | } |
| 673 | |
| 674 | /* cannot find frequency spec */ |
| 675 | |
| 676 | return -EINVAL; |
| 677 | |
| 678 | found: |
| 679 | *got = freq; |
| 680 | *iicon |= (divs-1); |
| 681 | *iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0; |
| 682 | return 0; |
| 683 | } |
| 684 | |
| 685 | /* s3c24xx_i2c_init |
| 686 | * |
| 687 | * initialise the controller, set the IO lines and frequency |
| 688 | */ |
| 689 | |
| 690 | static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c) |
| 691 | { |
| 692 | unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN; |
| 693 | struct s3c2410_platform_i2c *pdata; |
| 694 | unsigned int freq; |
| 695 | |
| 696 | /* get the plafrom data */ |
| 697 | |
| 698 | pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent); |
| 699 | |
| 700 | /* inititalise the gpio */ |
| 701 | |
| 702 | s3c2410_gpio_cfgpin(S3C2410_GPE15, S3C2410_GPE15_IICSDA); |
| 703 | s3c2410_gpio_cfgpin(S3C2410_GPE14, S3C2410_GPE14_IICSCL); |
| 704 | |
| 705 | /* write slave address */ |
| 706 | |
| 707 | writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD); |
| 708 | |
| 709 | dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr); |
| 710 | |
| 711 | /* we need to work out the divisors for the clock... */ |
| 712 | |
| 713 | if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) { |
| 714 | dev_err(i2c->dev, "cannot meet bus frequency required\n"); |
| 715 | return -EINVAL; |
| 716 | } |
| 717 | |
| 718 | /* todo - check that the i2c lines aren't being dragged anywhere */ |
| 719 | |
| 720 | dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq); |
| 721 | dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon); |
| 722 | |
| 723 | writel(iicon, i2c->regs + S3C2410_IICCON); |
| 724 | |
| 725 | /* check for s3c2440 i2c controller */ |
| 726 | |
| 727 | if (s3c24xx_i2c_is2440(i2c)) { |
| 728 | dev_dbg(i2c->dev, "S3C2440_IICLC=%08x\n", pdata->sda_delay); |
| 729 | |
| 730 | writel(pdata->sda_delay, i2c->regs + S3C2440_IICLC); |
| 731 | } |
| 732 | |
| 733 | return 0; |
| 734 | } |
| 735 | |
| 736 | static void s3c24xx_i2c_free(struct s3c24xx_i2c *i2c) |
| 737 | { |
| 738 | if (i2c->clk != NULL && !IS_ERR(i2c->clk)) { |
| 739 | clk_disable(i2c->clk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | clk_put(i2c->clk); |
| 741 | i2c->clk = NULL; |
| 742 | } |
| 743 | |
| 744 | if (i2c->regs != NULL) { |
| 745 | iounmap(i2c->regs); |
| 746 | i2c->regs = NULL; |
| 747 | } |
| 748 | |
| 749 | if (i2c->ioarea != NULL) { |
| 750 | release_resource(i2c->ioarea); |
| 751 | kfree(i2c->ioarea); |
| 752 | i2c->ioarea = NULL; |
| 753 | } |
| 754 | } |
| 755 | |
| 756 | /* s3c24xx_i2c_probe |
| 757 | * |
| 758 | * called by the bus driver when a suitable device is found |
| 759 | */ |
| 760 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 761 | static int s3c24xx_i2c_probe(struct platform_device *pdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | struct s3c24xx_i2c *i2c = &s3c24xx_i2c; |
| 764 | struct resource *res; |
| 765 | int ret; |
| 766 | |
| 767 | /* find the clock and enable it */ |
| 768 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 769 | i2c->dev = &pdev->dev; |
| 770 | i2c->clk = clk_get(&pdev->dev, "i2c"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | if (IS_ERR(i2c->clk)) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 772 | dev_err(&pdev->dev, "cannot get clock\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | ret = -ENOENT; |
| 774 | goto out; |
| 775 | } |
| 776 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 777 | dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | clk_enable(i2c->clk); |
| 780 | |
| 781 | /* map the registers */ |
| 782 | |
| 783 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 784 | if (res == NULL) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 785 | dev_err(&pdev->dev, "cannot find IO resource\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | ret = -ENOENT; |
| 787 | goto out; |
| 788 | } |
| 789 | |
| 790 | i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1, |
| 791 | pdev->name); |
| 792 | |
| 793 | if (i2c->ioarea == NULL) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 794 | dev_err(&pdev->dev, "cannot request IO\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | ret = -ENXIO; |
| 796 | goto out; |
| 797 | } |
| 798 | |
| 799 | i2c->regs = ioremap(res->start, (res->end-res->start)+1); |
| 800 | |
| 801 | if (i2c->regs == NULL) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 802 | dev_err(&pdev->dev, "cannot map IO\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | ret = -ENXIO; |
| 804 | goto out; |
| 805 | } |
| 806 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 807 | dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | |
| 809 | /* setup info block for the i2c core */ |
| 810 | |
| 811 | i2c->adap.algo_data = i2c; |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 812 | i2c->adap.dev.parent = &pdev->dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | |
| 814 | /* initialise the i2c controller */ |
| 815 | |
| 816 | ret = s3c24xx_i2c_init(i2c); |
| 817 | if (ret != 0) |
| 818 | goto out; |
| 819 | |
| 820 | /* find the IRQ for this unit (note, this relies on the init call to |
| 821 | * ensure no current IRQs pending |
| 822 | */ |
| 823 | |
| 824 | res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| 825 | if (res == NULL) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 826 | dev_err(&pdev->dev, "cannot find IRQ\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | ret = -ENOENT; |
| 828 | goto out; |
| 829 | } |
| 830 | |
| 831 | ret = request_irq(res->start, s3c24xx_i2c_irq, SA_INTERRUPT, |
| 832 | pdev->name, i2c); |
| 833 | |
| 834 | if (ret != 0) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 835 | dev_err(&pdev->dev, "cannot claim IRQ\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | goto out; |
| 837 | } |
| 838 | |
| 839 | i2c->irq = res; |
| 840 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 841 | dev_dbg(&pdev->dev, "irq resource %p (%ld)\n", res, res->start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | |
| 843 | ret = i2c_add_adapter(&i2c->adap); |
| 844 | if (ret < 0) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 845 | dev_err(&pdev->dev, "failed to add bus to i2c core\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | goto out; |
| 847 | } |
| 848 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 849 | platform_set_drvdata(pdev, i2c); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 851 | dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | |
| 853 | out: |
| 854 | if (ret < 0) |
| 855 | s3c24xx_i2c_free(i2c); |
| 856 | |
| 857 | return ret; |
| 858 | } |
| 859 | |
| 860 | /* s3c24xx_i2c_remove |
| 861 | * |
| 862 | * called when device is removed from the bus |
| 863 | */ |
| 864 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 865 | static int s3c24xx_i2c_remove(struct platform_device *pdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 867 | struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | |
| 869 | if (i2c != NULL) { |
| 870 | s3c24xx_i2c_free(i2c); |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 871 | platform_set_drvdata(pdev, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | } |
| 873 | |
| 874 | return 0; |
| 875 | } |
| 876 | |
| 877 | #ifdef CONFIG_PM |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 878 | static int s3c24xx_i2c_resume(struct platform_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 880 | struct s3c24xx_i2c *i2c = platform_get_drvdata(dev); |
Russell King | 9480e30 | 2005-10-28 09:52:56 -0700 | [diff] [blame] | 881 | |
| 882 | if (i2c != NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | s3c24xx_i2c_init(i2c); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | |
| 885 | return 0; |
| 886 | } |
| 887 | |
| 888 | #else |
| 889 | #define s3c24xx_i2c_resume NULL |
| 890 | #endif |
| 891 | |
| 892 | /* device driver for platform bus bits */ |
| 893 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 894 | static struct platform_driver s3c2410_i2c_driver = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | .probe = s3c24xx_i2c_probe, |
| 896 | .remove = s3c24xx_i2c_remove, |
| 897 | .resume = s3c24xx_i2c_resume, |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 898 | .driver = { |
| 899 | .owner = THIS_MODULE, |
| 900 | .name = "s3c2410-i2c", |
| 901 | }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 902 | }; |
| 903 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 904 | static struct platform_driver s3c2440_i2c_driver = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | .probe = s3c24xx_i2c_probe, |
| 906 | .remove = s3c24xx_i2c_remove, |
| 907 | .resume = s3c24xx_i2c_resume, |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 908 | .driver = { |
| 909 | .owner = THIS_MODULE, |
| 910 | .name = "s3c2440-i2c", |
| 911 | }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | }; |
| 913 | |
| 914 | static int __init i2c_adap_s3c_init(void) |
| 915 | { |
| 916 | int ret; |
| 917 | |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 918 | ret = platform_driver_register(&s3c2410_i2c_driver); |
Russell King | e32e28e | 2005-10-30 16:32:27 +0000 | [diff] [blame] | 919 | if (ret == 0) { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 920 | ret = platform_driver_register(&s3c2440_i2c_driver); |
Russell King | e32e28e | 2005-10-30 16:32:27 +0000 | [diff] [blame] | 921 | if (ret) |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 922 | platform_driver_unregister(&s3c2410_i2c_driver); |
Russell King | e32e28e | 2005-10-30 16:32:27 +0000 | [diff] [blame] | 923 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | |
| 925 | return ret; |
| 926 | } |
| 927 | |
| 928 | static void __exit i2c_adap_s3c_exit(void) |
| 929 | { |
Russell King | 3ae5eae | 2005-11-09 22:32:44 +0000 | [diff] [blame] | 930 | platform_driver_unregister(&s3c2410_i2c_driver); |
| 931 | platform_driver_unregister(&s3c2440_i2c_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | } |
| 933 | |
| 934 | module_init(i2c_adap_s3c_init); |
| 935 | module_exit(i2c_adap_s3c_exit); |
| 936 | |
| 937 | MODULE_DESCRIPTION("S3C24XX I2C Bus driver"); |
| 938 | MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); |
| 939 | MODULE_LICENSE("GPL"); |