git.sur5r.net Git - u-boot/blob - drivers/i2c/mv_i2c.c

   1 /*
   2  * (C) Copyright 2000
   3  * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
   4  *
   5  * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   6  * Marius Groeger <mgroeger@sysgo.de>
   7  *
   8  * (C) Copyright 2003 Pengutronix e.K.
   9  * Robert Schwebel <r.schwebel@pengutronix.de>
  10  *
  11  * (C) Copyright 2011 Marvell Inc.
  12  * Lei Wen <leiwen@marvell.com>
  13  *
  14  * SPDX-License-Identifier:     GPL-2.0+
  15  *
  16  * Back ported to the 8xx platform (from the 8260 platform) by
  17  * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
  18  */
  19
  20 #include <common.h>
  21 #include <asm/io.h>
  22
  23 #include <i2c.h>
  24 #include "mv_i2c.h"
  25
  26 /* All transfers are described by this data structure */
  27 struct mv_i2c_msg {
  28         u8 condition;
  29         u8 acknack;
  30         u8 direction;
  31         u8 data;
  32 };
  33
  34 struct mv_i2c {
  35         u32 ibmr;
  36         u32 pad0;
  37         u32 idbr;
  38         u32 pad1;
  39         u32 icr;
  40         u32 pad2;
  41         u32 isr;
  42         u32 pad3;
  43         u32 isar;
  44 };
  45
  46 static struct mv_i2c *base;
  47 static void i2c_board_init(struct mv_i2c *base)
  48 {
  49 #ifdef CONFIG_SYS_I2C_INIT_BOARD
  50         u32 icr;
  51         /*
  52          * call board specific i2c bus reset routine before accessing the
  53          * environment, which might be in a chip on that bus. For details
  54          * about this problem see doc/I2C_Edge_Conditions.
  55          *
  56          * disable I2C controller first, otherwhise it thinks we want to
  57          * talk to the slave port...
  58          */
  59         icr = readl(&base->icr);
  60         writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
  61
  62         i2c_init_board();
  63
  64         writel(icr, &base->icr);
  65 #endif
  66 }
  67
  68 #ifdef CONFIG_I2C_MULTI_BUS
  69 static unsigned long i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG;
  70 static unsigned int bus_initialized[CONFIG_MV_I2C_NUM];
  71 static unsigned int current_bus;
  72
  73 int i2c_set_bus_num(unsigned int bus)
  74 {
  75         if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) {
  76                 printf("Bad bus: %d\n", bus);
  77                 return -1;
  78         }
  79
  80         base = (struct mv_i2c *)i2c_regs[bus];
  81         current_bus = bus;
  82
  83         if (!bus_initialized[current_bus]) {
  84                 i2c_board_init(base);
  85                 bus_initialized[current_bus] = 1;
  86         }
  87
  88         return 0;
  89 }
  90
  91 unsigned int i2c_get_bus_num(void)
  92 {
  93         return current_bus;
  94 }
  95 #endif
  96
  97 /*
  98  * i2c_reset: - reset the host controller
  99  *
 100  */
 101 static void i2c_reset(void)
 102 {
 103         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
 104         writel(readl(&base->icr) | ICR_UR, &base->icr);   /* reset the unit */
 105         udelay(100);
 106         writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
 107
 108         i2c_clk_enable();
 109
 110         writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
 111         writel(I2C_ICR_INIT, &base->icr); /* set control reg values */
 112         writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
 113         writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
 114         udelay(100);
 115 }
 116
 117 /*
 118  * i2c_isr_set_cleared: - wait until certain bits of the I2C status register
 119  *                        are set and cleared
 120  *
 121  * @return: 1 in case of success, 0 means timeout (no match within 10 ms).
 122  */
 123 static int i2c_isr_set_cleared(unsigned long set_mask,
 124                                unsigned long cleared_mask)
 125 {
 126         int timeout = 1000, isr;
 127
 128         do {
 129                 isr = readl(&base->isr);
 130                 udelay(10);
 131                 if (timeout-- < 0)
 132                         return 0;
 133         } while (((isr & set_mask) != set_mask)
 134                 || ((isr & cleared_mask) != 0));
 135
 136         return 1;
 137 }
 138
 139 /*
 140  * i2c_transfer: - Transfer one byte over the i2c bus
 141  *
 142  * This function can tranfer a byte over the i2c bus in both directions.
 143  * It is used by the public API functions.
 144  *
 145  * @return:  0: transfer successful
 146  *          -1: message is empty
 147  *          -2: transmit timeout
 148  *          -3: ACK missing
 149  *          -4: receive timeout
 150  *          -5: illegal parameters
 151  *          -6: bus is busy and couldn't be aquired
 152  */
 153 int i2c_transfer(struct mv_i2c_msg *msg)
 154 {
 155         int ret;
 156
 157         if (!msg)
 158                 goto transfer_error_msg_empty;
 159
 160         switch (msg->direction) {
 161         case I2C_WRITE:
 162                 /* check if bus is not busy */
 163                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 164                         goto transfer_error_bus_busy;
 165
 166                 /* start transmission */
 167                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 168                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 169                 writel(msg->data, &base->idbr);
 170                 if (msg->condition == I2C_COND_START)
 171                         writel(readl(&base->icr) | ICR_START, &base->icr);
 172                 if (msg->condition == I2C_COND_STOP)
 173                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 174                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 175                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 176                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 177                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 178                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 179                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 180
 181                 /* transmit register empty? */
 182                 if (!i2c_isr_set_cleared(ISR_ITE, 0))
 183                         goto transfer_error_transmit_timeout;
 184
 185                 /* clear 'transmit empty' state */
 186                 writel(readl(&base->isr) | ISR_ITE, &base->isr);
 187
 188                 /* wait for ACK from slave */
 189                 if (msg->acknack == I2C_ACKNAK_WAITACK)
 190                         if (!i2c_isr_set_cleared(0, ISR_ACKNAK))
 191                                 goto transfer_error_ack_missing;
 192                 break;
 193
 194         case I2C_READ:
 195
 196                 /* check if bus is not busy */
 197                 if (!i2c_isr_set_cleared(0, ISR_IBB))
 198                         goto transfer_error_bus_busy;
 199
 200                 /* start receive */
 201                 writel(readl(&base->icr) & ~ICR_START, &base->icr);
 202                 writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
 203                 if (msg->condition == I2C_COND_START)
 204                         writel(readl(&base->icr) | ICR_START, &base->icr);
 205                 if (msg->condition == I2C_COND_STOP)
 206                         writel(readl(&base->icr) | ICR_STOP, &base->icr);
 207                 if (msg->acknack == I2C_ACKNAK_SENDNAK)
 208                         writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
 209                 if (msg->acknack == I2C_ACKNAK_SENDACK)
 210                         writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
 211                 writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
 212                 writel(readl(&base->icr) | ICR_TB, &base->icr);
 213
 214                 /* receive register full? */
 215                 if (!i2c_isr_set_cleared(ISR_IRF, 0))
 216                         goto transfer_error_receive_timeout;
 217
 218                 msg->data = readl(&base->idbr);
 219
 220                 /* clear 'receive empty' state */
 221                 writel(readl(&base->isr) | ISR_IRF, &base->isr);
 222                 break;
 223         default:
 224                 goto transfer_error_illegal_param;
 225         }
 226
 227         return 0;
 228
 229 transfer_error_msg_empty:
 230         debug("i2c_transfer: error: 'msg' is empty\n");
 231         ret = -1;
 232         goto i2c_transfer_finish;
 233
 234 transfer_error_transmit_timeout:
 235         debug("i2c_transfer: error: transmit timeout\n");
 236         ret = -2;
 237         goto i2c_transfer_finish;
 238
 239 transfer_error_ack_missing:
 240         debug("i2c_transfer: error: ACK missing\n");
 241         ret = -3;
 242         goto i2c_transfer_finish;
 243
 244 transfer_error_receive_timeout:
 245         debug("i2c_transfer: error: receive timeout\n");
 246         ret = -4;
 247         goto i2c_transfer_finish;
 248
 249 transfer_error_illegal_param:
 250         debug("i2c_transfer: error: illegal parameters\n");
 251         ret = -5;
 252         goto i2c_transfer_finish;
 253
 254 transfer_error_bus_busy:
 255         debug("i2c_transfer: error: bus is busy\n");
 256         ret = -6;
 257         goto i2c_transfer_finish;
 258
 259 i2c_transfer_finish:
 260         debug("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr));
 261         i2c_reset();
 262         return ret;
 263 }
 264
 265 /* ------------------------------------------------------------------------ */
 266 /* API Functions                                                            */
 267 /* ------------------------------------------------------------------------ */
 268 void i2c_init(int speed, int slaveaddr)
 269 {
 270 #ifdef CONFIG_I2C_MULTI_BUS
 271         current_bus = 0;
 272         base = (struct mv_i2c *)i2c_regs[current_bus];
 273 #else
 274         base = (struct mv_i2c *)CONFIG_MV_I2C_REG;
 275 #endif
 276
 277         i2c_board_init(base);
 278 }
 279
 280 /*
 281  * i2c_probe: - Test if a chip answers for a given i2c address
 282  *
 283  * @chip:       address of the chip which is searched for
 284  * @return:     0 if a chip was found, -1 otherwhise
 285  */
 286 int i2c_probe(uchar chip)
 287 {
 288         struct mv_i2c_msg msg;
 289
 290         i2c_reset();
 291
 292         msg.condition = I2C_COND_START;
 293         msg.acknack   = I2C_ACKNAK_WAITACK;
 294         msg.direction = I2C_WRITE;
 295         msg.data      = (chip << 1) + 1;
 296         if (i2c_transfer(&msg))
 297                 return -1;
 298
 299         msg.condition = I2C_COND_STOP;
 300         msg.acknack   = I2C_ACKNAK_SENDNAK;
 301         msg.direction = I2C_READ;
 302         msg.data      = 0x00;
 303         if (i2c_transfer(&msg))
 304                 return -1;
 305
 306         return 0;
 307 }
 308
 309 /*
 310  * i2c_read: - Read multiple bytes from an i2c device
 311  *
 312  * The higher level routines take into account that this function is only
 313  * called with len < page length of the device (see configuration file)
 314  *
 315  * @chip:       address of the chip which is to be read
 316  * @addr:       i2c data address within the chip
 317  * @alen:       length of the i2c data address (1..2 bytes)
 318  * @buffer:     where to write the data
 319  * @len:        how much byte do we want to read
 320  * @return:     0 in case of success
 321  */
 322 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 323 {
 324         struct mv_i2c_msg msg;
 325         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 326
 327         debug("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 328               "len=0x%02x)\n", chip, addr, alen, len);
 329
 330         i2c_reset();
 331
 332         /* dummy chip address write */
 333         debug("i2c_read: dummy chip address write\n");
 334         msg.condition = I2C_COND_START;
 335         msg.acknack   = I2C_ACKNAK_WAITACK;
 336         msg.direction = I2C_WRITE;
 337         msg.data = (chip << 1);
 338         msg.data &= 0xFE;
 339         if (i2c_transfer(&msg))
 340                 return -1;
 341
 342         /*
 343          * send memory address bytes;
 344          * alen defines how much bytes we have to send.
 345          */
 346         /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
 347         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 348         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 349         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 350
 351         while (--alen >= 0) {
 352                 debug("i2c_read: send memory word address byte %1d\n", alen);
 353                 msg.condition = I2C_COND_NORMAL;
 354                 msg.acknack   = I2C_ACKNAK_WAITACK;
 355                 msg.direction = I2C_WRITE;
 356                 msg.data      = addr_bytes[alen];
 357                 if (i2c_transfer(&msg))
 358                         return -1;
 359         }
 360
 361         /* start read sequence */
 362         debug("i2c_read: start read sequence\n");
 363         msg.condition = I2C_COND_START;
 364         msg.acknack   = I2C_ACKNAK_WAITACK;
 365         msg.direction = I2C_WRITE;
 366         msg.data      = (chip << 1);
 367         msg.data     |= 0x01;
 368         if (i2c_transfer(&msg))
 369                 return -1;
 370
 371         /* read bytes; send NACK at last byte */
 372         while (len--) {
 373                 if (len == 0) {
 374                         msg.condition = I2C_COND_STOP;
 375                         msg.acknack   = I2C_ACKNAK_SENDNAK;
 376                 } else {
 377                         msg.condition = I2C_COND_NORMAL;
 378                         msg.acknack   = I2C_ACKNAK_SENDACK;
 379                 }
 380
 381                 msg.direction = I2C_READ;
 382                 msg.data      = 0x00;
 383                 if (i2c_transfer(&msg))
 384                         return -1;
 385
 386                 *buffer = msg.data;
 387                 debug("i2c_read: reading byte (0x%08x)=0x%02x\n",
 388                       (unsigned int)buffer, *buffer);
 389                 buffer++;
 390         }
 391
 392         i2c_reset();
 393
 394         return 0;
 395 }
 396
 397 /*
 398  * i2c_write: -  Write multiple bytes to an i2c device
 399  *
 400  * The higher level routines take into account that this function is only
 401  * called with len < page length of the device (see configuration file)
 402  *
 403  * @chip:       address of the chip which is to be written
 404  * @addr:       i2c data address within the chip
 405  * @alen:       length of the i2c data address (1..2 bytes)
 406  * @buffer:     where to find the data to be written
 407  * @len:        how much byte do we want to read
 408  * @return:     0 in case of success
 409  */
 410 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 411 {
 412         struct mv_i2c_msg msg;
 413         u8 addr_bytes[3]; /* lowest...highest byte of data address */
 414
 415         debug("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
 416               "len=0x%02x)\n", chip, addr, alen, len);
 417
 418         i2c_reset();
 419
 420         /* chip address write */
 421         debug("i2c_write: chip address write\n");
 422         msg.condition = I2C_COND_START;
 423         msg.acknack   = I2C_ACKNAK_WAITACK;
 424         msg.direction = I2C_WRITE;
 425         msg.data = (chip << 1);
 426         msg.data &= 0xFE;
 427         if (i2c_transfer(&msg))
 428                 return -1;
 429
 430         /*
 431          * send memory address bytes;
 432          * alen defines how much bytes we have to send.
 433          */
 434         addr_bytes[0] = (u8)((addr >>  0) & 0x000000FF);
 435         addr_bytes[1] = (u8)((addr >>  8) & 0x000000FF);
 436         addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
 437
 438         while (--alen >= 0) {
 439                 debug("i2c_write: send memory word address\n");
 440                 msg.condition = I2C_COND_NORMAL;
 441                 msg.acknack   = I2C_ACKNAK_WAITACK;
 442                 msg.direction = I2C_WRITE;
 443                 msg.data      = addr_bytes[alen];
 444                 if (i2c_transfer(&msg))
 445                         return -1;
 446         }
 447
 448         /* write bytes; send NACK at last byte */
 449         while (len--) {
 450                 debug("i2c_write: writing byte (0x%08x)=0x%02x\n",
 451                       (unsigned int)buffer, *buffer);
 452
 453                 if (len == 0)
 454                         msg.condition = I2C_COND_STOP;
 455                 else
 456                         msg.condition = I2C_COND_NORMAL;
 457
 458                 msg.acknack   = I2C_ACKNAK_WAITACK;
 459                 msg.direction = I2C_WRITE;
 460                 msg.data      = *(buffer++);
 461
 462                 if (i2c_transfer(&msg))
 463                         return -1;
 464         }
 465
 466         i2c_reset();
 467
 468         return 0;
 469 }