drivers/i2c/kirkwood_i2c.c

   1 /*
   2  * Driver for the i2c controller on the Marvell line of host bridges
   3  * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, Orion SoC family),
   4  * and Kirkwood family.
   5  *
   6  * Based on:
   7  * Author: Mark A. Greer <mgreer@mvista.com>
   8  * 2005 (c) MontaVista, Software, Inc.
   9  *
  10  * See file CREDITS for list of people who contributed to this
  11  * project.
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License as
  15  * published by the Free Software Foundation; either version 2 of
  16  * the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  26  * MA 02110-1301 USA
  27  *
  28  * ported from Linux to u-boot
  29  * (C) Copyright 2009
  30  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
  31  */
  32 #include <common.h>
  33 #include <i2c.h>
  34 #include <asm/arch/kirkwood.h>
  35 #include <asm/errno.h>
  36 #include <asm/io.h>
  37
  38 DECLARE_GLOBAL_DATA_PTR;
  39
  40 static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = 0;
  41 #if defined(CONFIG_I2C_MUX)
  42 static unsigned int i2c_bus_num_mux __attribute__ ((section ("data"))) = 0;
  43 #endif
  44
  45 /* Register defines */
  46 #define KW_I2C_REG_SLAVE_ADDR                   0x00
  47 #define KW_I2C_REG_DATA                         0x04
  48 #define KW_I2C_REG_CONTROL                      0x08
  49 #define KW_I2C_REG_STATUS                       0x0c
  50 #define KW_I2C_REG_BAUD                         0x0c
  51 #define KW_I2C_REG_EXT_SLAVE_ADDR               0x10
  52 #define KW_I2C_REG_SOFT_RESET                   0x1c
  53
  54 #define KW_I2C_REG_CONTROL_ACK                  0x00000004
  55 #define KW_I2C_REG_CONTROL_IFLG                 0x00000008
  56 #define KW_I2C_REG_CONTROL_STOP                 0x00000010
  57 #define KW_I2C_REG_CONTROL_START                0x00000020
  58 #define KW_I2C_REG_CONTROL_TWSIEN               0x00000040
  59 #define KW_I2C_REG_CONTROL_INTEN                0x00000080
  60
  61 /* Ctlr status values */
  62 #define KW_I2C_STATUS_BUS_ERR                   0x00
  63 #define KW_I2C_STATUS_MAST_START                0x08
  64 #define KW_I2C_STATUS_MAST_REPEAT_START         0x10
  65 #define KW_I2C_STATUS_MAST_WR_ADDR_ACK          0x18
  66 #define KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK       0x20
  67 #define KW_I2C_STATUS_MAST_WR_ACK               0x28
  68 #define KW_I2C_STATUS_MAST_WR_NO_ACK            0x30
  69 #define KW_I2C_STATUS_MAST_LOST_ARB             0x38
  70 #define KW_I2C_STATUS_MAST_RD_ADDR_ACK          0x40
  71 #define KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK       0x48
  72 #define KW_I2C_STATUS_MAST_RD_DATA_ACK          0x50
  73 #define KW_I2C_STATUS_MAST_RD_DATA_NO_ACK       0x58
  74 #define KW_I2C_STATUS_MAST_WR_ADDR_2_ACK        0xd0
  75 #define KW_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK     0xd8
  76 #define KW_I2C_STATUS_MAST_RD_ADDR_2_ACK        0xe0
  77 #define KW_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK     0xe8
  78 #define KW_I2C_STATUS_NO_STATUS                 0xf8
  79
  80 /* Driver states */
  81 enum {
  82         KW_I2C_STATE_INVALID,
  83         KW_I2C_STATE_IDLE,
  84         KW_I2C_STATE_WAITING_FOR_START_COND,
  85         KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
  86         KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
  87         KW_I2C_STATE_WAITING_FOR_SLAVE_ACK,
  88         KW_I2C_STATE_WAITING_FOR_SLAVE_DATA,
  89 };
  90
  91 /* Driver actions */
  92 enum {
  93         KW_I2C_ACTION_INVALID,
  94         KW_I2C_ACTION_CONTINUE,
  95         KW_I2C_ACTION_SEND_START,
  96         KW_I2C_ACTION_SEND_ADDR_1,
  97         KW_I2C_ACTION_SEND_ADDR_2,
  98         KW_I2C_ACTION_SEND_DATA,
  99         KW_I2C_ACTION_RCV_DATA,
 100         KW_I2C_ACTION_RCV_DATA_STOP,
 101         KW_I2C_ACTION_SEND_STOP,
 102 };
 103
 104 /* defines to get compatible with Linux driver */
 105 #define IRQ_NONE        0x0
 106 #define IRQ_HANDLED     0x01
 107
 108 #define I2C_M_TEN       0x01
 109 #define I2C_M_RD        0x02
 110 #define I2C_M_REV_DIR_ADDR      0x04;
 111
 112 struct i2c_msg {
 113         u32     addr;
 114         u32     flags;
 115         u8      *buf;
 116         u32     len;
 117 };
 118
 119 struct kirkwood_i2c_data {
 120         int                     irq;
 121         u32                     state;
 122         u32                     action;
 123         u32                     aborting;
 124         u32                     cntl_bits;
 125         void                    *reg_base;
 126         u32                     reg_base_p;
 127         u32                     reg_size;
 128         u32                     addr1;
 129         u32                     addr2;
 130         u32                     bytes_left;
 131         u32                     byte_posn;
 132         u32                     block;
 133         int                     rc;
 134         u32                     freq_m;
 135         u32                     freq_n;
 136         struct i2c_msg          *msg;
 137 };
 138
 139 static struct kirkwood_i2c_data __drv_data __attribute__ ((section (".data")));
 140 static struct kirkwood_i2c_data *drv_data = &__drv_data;
 141 static struct i2c_msg __i2c_msg __attribute__ ((section (".data")));
 142 static struct i2c_msg *kirkwood_i2c_msg = &__i2c_msg;
 143
 144 /*
 145  *****************************************************************************
 146  *
 147  *      Finite State Machine & Interrupt Routines
 148  *
 149  *****************************************************************************
 150  */
 151
 152 static inline int abs(int n)
 153 {
 154          if(n >= 0)
 155                 return n;
 156         else
 157                 return n * -1;
 158 }
 159
 160 static void kirkwood_calculate_speed(int speed)
 161 {
 162         int     calcspeed;
 163         int     diff;
 164         int     best_diff = CONFIG_SYS_TCLK;
 165         int     best_speed = 0;
 166         int     m, n;
 167         int     tmp[8] = {2, 4, 8, 16, 32, 64, 128, 256};
 168
 169         for (n = 0; n < 8; n++) {
 170                 for (m = 0; m < 16; m++) {
 171                         calcspeed = CONFIG_SYS_TCLK / (10 * (m + 1) * tmp[n]);
 172                         diff = abs((speed - calcspeed));
 173                         if ( diff < best_diff) {
 174                                 best_diff = diff;
 175                                 best_speed = calcspeed;
 176                                 drv_data->freq_m = m;
 177                                 drv_data->freq_n = n;
 178                         }
 179                 }
 180         }
 181 }
 182
 183 /* Reset hardware and initialize FSM */
 184 static void
 185 kirkwood_i2c_hw_init(int speed, int slaveadd)
 186 {
 187         drv_data->state = KW_I2C_STATE_IDLE;
 188
 189         kirkwood_calculate_speed(speed);
 190         writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SOFT_RESET);
 191         writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
 192                 CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_BAUD);
 193         writel(slaveadd, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SLAVE_ADDR);
 194         writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_EXT_SLAVE_ADDR);
 195         writel(KW_I2C_REG_CONTROL_TWSIEN | KW_I2C_REG_CONTROL_STOP,
 196                 CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 197 }
 198
 199 static void
 200 kirkwood_i2c_fsm(u32 status)
 201 {
 202         /*
 203          * If state is idle, then this is likely the remnants of an old
 204          * operation that driver has given up on or the user has killed.
 205          * If so, issue the stop condition and go to idle.
 206          */
 207         if (drv_data->state == KW_I2C_STATE_IDLE) {
 208                 drv_data->action = KW_I2C_ACTION_SEND_STOP;
 209                 return;
 210         }
 211
 212         /* The status from the ctlr [mostly] tells us what to do next */
 213         switch (status) {
 214         /* Start condition interrupt */
 215         case KW_I2C_STATUS_MAST_START: /* 0x08 */
 216         case KW_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
 217                 drv_data->action = KW_I2C_ACTION_SEND_ADDR_1;
 218                 drv_data->state = KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
 219                 break;
 220
 221         /* Performing a write */
 222         case KW_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
 223                 if (drv_data->msg->flags & I2C_M_TEN) {
 224                         drv_data->action = KW_I2C_ACTION_SEND_ADDR_2;
 225                         drv_data->state =
 226                                 KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
 227                         break;
 228                 }
 229                 /* FALLTHRU */
 230         case KW_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
 231         case KW_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
 232                 if ((drv_data->bytes_left == 0)
 233                                 || (drv_data->aborting
 234                                         && (drv_data->byte_posn != 0))) {
 235                         drv_data->action = KW_I2C_ACTION_SEND_STOP;
 236                         drv_data->state = KW_I2C_STATE_IDLE;
 237                 } else {
 238                         drv_data->action = KW_I2C_ACTION_SEND_DATA;
 239                         drv_data->state =
 240                                 KW_I2C_STATE_WAITING_FOR_SLAVE_ACK;
 241                         drv_data->bytes_left--;
 242                 }
 243                 break;
 244
 245         /* Performing a read */
 246         case KW_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
 247                 if (drv_data->msg->flags & I2C_M_TEN) {
 248                         drv_data->action = KW_I2C_ACTION_SEND_ADDR_2;
 249                         drv_data->state =
 250                                 KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
 251                         break;
 252                 }
 253                 /* FALLTHRU */
 254         case KW_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
 255                 if (drv_data->bytes_left == 0) {
 256                         drv_data->action = KW_I2C_ACTION_SEND_STOP;
 257                         drv_data->state = KW_I2C_STATE_IDLE;
 258                         break;
 259                 }
 260                 /* FALLTHRU */
 261         case KW_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
 262                 if (status != KW_I2C_STATUS_MAST_RD_DATA_ACK)
 263                         drv_data->action = KW_I2C_ACTION_CONTINUE;
 264                 else {
 265                         drv_data->action = KW_I2C_ACTION_RCV_DATA;
 266                         drv_data->bytes_left--;
 267                 }
 268                 drv_data->state = KW_I2C_STATE_WAITING_FOR_SLAVE_DATA;
 269
 270                 if ((drv_data->bytes_left == 1) || drv_data->aborting)
 271                         drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_ACK;
 272                 break;
 273
 274         case KW_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
 275                 drv_data->action = KW_I2C_ACTION_RCV_DATA_STOP;
 276                 drv_data->state = KW_I2C_STATE_IDLE;
 277                 break;
 278
 279         case KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
 280         case KW_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
 281         case KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
 282                 /* Doesn't seem to be a device at other end */
 283                 drv_data->action = KW_I2C_ACTION_SEND_STOP;
 284                 drv_data->state = KW_I2C_STATE_IDLE;
 285                 drv_data->rc = -ENODEV;
 286                 break;
 287
 288         default:
 289                 printf("kirkwood_i2c_fsm: Ctlr Error -- state: 0x%x, "
 290                         "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
 291                          drv_data->state, status, drv_data->msg->addr,
 292                          drv_data->msg->flags);
 293                 drv_data->action = KW_I2C_ACTION_SEND_STOP;
 294                 kirkwood_i2c_hw_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 295                 drv_data->rc = -EIO;
 296         }
 297 }
 298
 299 static void
 300 kirkwood_i2c_do_action(void)
 301 {
 302         switch(drv_data->action) {
 303         case KW_I2C_ACTION_CONTINUE:
 304                 writel(drv_data->cntl_bits,
 305                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 306                 break;
 307
 308         case KW_I2C_ACTION_SEND_START:
 309                 writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_START,
 310                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 311                 break;
 312
 313         case KW_I2C_ACTION_SEND_ADDR_1:
 314                 writel(drv_data->addr1,
 315                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
 316                 writel(drv_data->cntl_bits,
 317                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 318                 break;
 319
 320         case KW_I2C_ACTION_SEND_ADDR_2:
 321                 writel(drv_data->addr2,
 322                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
 323                 writel(drv_data->cntl_bits,
 324                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 325                 break;
 326
 327         case KW_I2C_ACTION_SEND_DATA:
 328                 writel(drv_data->msg->buf[drv_data->byte_posn++],
 329                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
 330                 writel(drv_data->cntl_bits,
 331                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 332                 break;
 333
 334         case KW_I2C_ACTION_RCV_DATA:
 335                 drv_data->msg->buf[drv_data->byte_posn++] =
 336                         readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
 337                 writel(drv_data->cntl_bits,
 338                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 339                 break;
 340
 341         case KW_I2C_ACTION_RCV_DATA_STOP:
 342                 drv_data->msg->buf[drv_data->byte_posn++] =
 343                         readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
 344                 drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN;
 345                 writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP,
 346                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 347                 drv_data->block = 0;
 348                 break;
 349
 350         case KW_I2C_ACTION_INVALID:
 351         default:
 352                 printf("kirkwood_i2c_do_action: Invalid action: %d\n",
 353                         drv_data->action);
 354                 drv_data->rc = -EIO;
 355                 /* FALLTHRU */
 356         case KW_I2C_ACTION_SEND_STOP:
 357                 drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN;
 358                 writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP,
 359                         CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 360                 drv_data->block = 0;
 361                 break;
 362         }
 363 }
 364
 365 static  int
 366 kirkwood_i2c_intr(void)
 367 {
 368         u32             status;
 369         u32             ctrl;
 370         int             rc = IRQ_NONE;
 371
 372         ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 373         while ((ctrl & KW_I2C_REG_CONTROL_IFLG) &&
 374                 (drv_data->rc == 0)) {
 375                 status = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_STATUS);
 376                 kirkwood_i2c_fsm(status);
 377                 kirkwood_i2c_do_action();
 378                 rc = IRQ_HANDLED;
 379                 ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
 380                 udelay(1000);
 381         }
 382         return rc;
 383 }
 384
 385 static void
 386 kirkwood_i2c_doio(struct i2c_msg *msg)
 387 {
 388         int     ret;
 389
 390         while ((drv_data->rc == 0) && (drv_data->state != KW_I2C_STATE_IDLE)) {
 391                 /* poll Status register */
 392                 ret = kirkwood_i2c_intr();
 393                 if (ret == IRQ_NONE)
 394                         udelay(10);
 395         }
 396 }
 397
 398 static void
 399 kirkwood_i2c_prepare_for_io(struct i2c_msg *msg)
 400 {
 401         u32     dir = 0;
 402
 403         drv_data->msg = msg;
 404         drv_data->byte_posn = 0;
 405         drv_data->bytes_left = msg->len;
 406         drv_data->aborting = 0;
 407         drv_data->rc = 0;
 408         /* in u-boot we use no IRQs */
 409         drv_data->cntl_bits = KW_I2C_REG_CONTROL_ACK | KW_I2C_REG_CONTROL_TWSIEN;
 410
 411         if (msg->flags & I2C_M_RD)
 412                 dir = 1;
 413         if (msg->flags & I2C_M_TEN) {
 414                 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
 415                 drv_data->addr2 = (u32)msg->addr & 0xff;
 416         } else {
 417                 drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
 418                 drv_data->addr2 = 0;
 419         }
 420         /* OK, no start it (from kirkwood_i2c_execute_msg())*/
 421         drv_data->action = KW_I2C_ACTION_SEND_START;
 422         drv_data->state = KW_I2C_STATE_WAITING_FOR_START_COND;
 423         drv_data->block = 1;
 424         kirkwood_i2c_do_action();
 425 }
 426
 427 void
 428 i2c_init(int speed, int slaveadd)
 429 {
 430         kirkwood_i2c_hw_init(speed, slaveadd);
 431 }
 432
 433 int
 434 i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
 435 {
 436         kirkwood_i2c_msg->buf = data;
 437         kirkwood_i2c_msg->len = length;
 438         kirkwood_i2c_msg->addr = dev;
 439         kirkwood_i2c_msg->flags = I2C_M_RD;
 440
 441         kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg);
 442         kirkwood_i2c_doio(kirkwood_i2c_msg);
 443         return drv_data->rc;
 444 }
 445
 446 int
 447 i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
 448 {
 449         kirkwood_i2c_msg->buf = data;
 450         kirkwood_i2c_msg->len = length;
 451         kirkwood_i2c_msg->addr = dev;
 452         kirkwood_i2c_msg->flags = 0;
 453
 454         kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg);
 455         kirkwood_i2c_doio(kirkwood_i2c_msg);
 456         return drv_data->rc;
 457 }
 458
 459 int
 460 i2c_probe(uchar chip)
 461 {
 462         return i2c_read(chip, 0, 0, NULL, 0);
 463 }
 464
 465 int i2c_set_bus_num(unsigned int bus)
 466 {
 467 #if defined(CONFIG_I2C_MUX)
 468         if (bus < CONFIG_SYS_MAX_I2C_BUS) {
 469                 i2c_bus_num = bus;
 470         } else {
 471                 int     ret;
 472
 473                 ret = i2x_mux_select_mux(bus);
 474                 if (ret)
 475                         return ret;
 476                 i2c_bus_num = 0;
 477         }
 478         i2c_bus_num_mux = bus;
 479 #else
 480         if (bus > 0) {
 481                 return -1;
 482         }
 483
 484         i2c_bus_num = bus;
 485 #endif
 486         return 0;
 487 }
 488
 489 unsigned int i2c_get_bus_num(void)
 490 {
 491 #if defined(CONFIG_I2C_MUX)
 492         return i2c_bus_num_mux;
 493 #else
 494         return i2c_bus_num;
 495 #endif
 496 }