drivers/i2c/designware_i2c.c

   1 /*
   2  * (C) Copyright 2009
   3  * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <asm/io.h>
  10 #include <asm/arch/hardware.h>
  11 #include "designware_i2c.h"
  12
  13 #ifdef CONFIG_I2C_MULTI_BUS
  14 static unsigned int bus_initialized[CONFIG_SYS_I2C_BUS_MAX];
  15 static unsigned int current_bus = 0;
  16 #endif
  17
  18 static struct i2c_regs *i2c_regs_p =
  19     (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
  20
  21 /*
  22  * set_speed - Set the i2c speed mode (standard, high, fast)
  23  * @i2c_spd:    required i2c speed mode
  24  *
  25  * Set the i2c speed mode (standard, high, fast)
  26  */
  27 static void set_speed(int i2c_spd)
  28 {
  29         unsigned int cntl;
  30         unsigned int hcnt, lcnt;
  31         unsigned int enbl;
  32
  33         /* to set speed cltr must be disabled */
  34         enbl = readl(&i2c_regs_p->ic_enable);
  35         enbl &= ~IC_ENABLE_0B;
  36         writel(enbl, &i2c_regs_p->ic_enable);
  37
  38         cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK));
  39
  40         switch (i2c_spd) {
  41         case IC_SPEED_MODE_MAX:
  42                 cntl |= IC_CON_SPD_HS;
  43                 hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
  44                 writel(hcnt, &i2c_regs_p->ic_hs_scl_hcnt);
  45                 lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
  46                 writel(lcnt, &i2c_regs_p->ic_hs_scl_lcnt);
  47                 break;
  48
  49         case IC_SPEED_MODE_STANDARD:
  50                 cntl |= IC_CON_SPD_SS;
  51                 hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
  52                 writel(hcnt, &i2c_regs_p->ic_ss_scl_hcnt);
  53                 lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
  54                 writel(lcnt, &i2c_regs_p->ic_ss_scl_lcnt);
  55                 break;
  56
  57         case IC_SPEED_MODE_FAST:
  58         default:
  59                 cntl |= IC_CON_SPD_FS;
  60                 hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
  61                 writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
  62                 lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
  63                 writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
  64                 break;
  65         }
  66
  67         writel(cntl, &i2c_regs_p->ic_con);
  68
  69         /* Enable back i2c now speed set */
  70         enbl |= IC_ENABLE_0B;
  71         writel(enbl, &i2c_regs_p->ic_enable);
  72 }
  73
  74 /*
  75  * i2c_set_bus_speed - Set the i2c speed
  76  * @speed:      required i2c speed
  77  *
  78  * Set the i2c speed.
  79  */
  80 int i2c_set_bus_speed(int speed)
  81 {
  82         if (speed >= I2C_MAX_SPEED)
  83                 set_speed(IC_SPEED_MODE_MAX);
  84         else if (speed >= I2C_FAST_SPEED)
  85                 set_speed(IC_SPEED_MODE_FAST);
  86         else
  87                 set_speed(IC_SPEED_MODE_STANDARD);
  88
  89         return 0;
  90 }
  91
  92 /*
  93  * i2c_get_bus_speed - Gets the i2c speed
  94  *
  95  * Gets the i2c speed.
  96  */
  97 int i2c_get_bus_speed(void)
  98 {
  99         u32 cntl;
 100
 101         cntl = (readl(&i2c_regs_p->ic_con) & IC_CON_SPD_MSK);
 102
 103         if (cntl == IC_CON_SPD_HS)
 104                 return I2C_MAX_SPEED;
 105         else if (cntl == IC_CON_SPD_FS)
 106                 return I2C_FAST_SPEED;
 107         else if (cntl == IC_CON_SPD_SS)
 108                 return I2C_STANDARD_SPEED;
 109
 110         return 0;
 111 }
 112
 113 /*
 114  * i2c_init - Init function
 115  * @speed:      required i2c speed
 116  * @slaveadd:   slave address for the device
 117  *
 118  * Initialization function.
 119  */
 120 void i2c_init(int speed, int slaveadd)
 121 {
 122         unsigned int enbl;
 123
 124         /* Disable i2c */
 125         enbl = readl(&i2c_regs_p->ic_enable);
 126         enbl &= ~IC_ENABLE_0B;
 127         writel(enbl, &i2c_regs_p->ic_enable);
 128
 129         writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_regs_p->ic_con);
 130         writel(IC_RX_TL, &i2c_regs_p->ic_rx_tl);
 131         writel(IC_TX_TL, &i2c_regs_p->ic_tx_tl);
 132         i2c_set_bus_speed(speed);
 133         writel(IC_STOP_DET, &i2c_regs_p->ic_intr_mask);
 134         writel(slaveadd, &i2c_regs_p->ic_sar);
 135
 136         /* Enable i2c */
 137         enbl = readl(&i2c_regs_p->ic_enable);
 138         enbl |= IC_ENABLE_0B;
 139         writel(enbl, &i2c_regs_p->ic_enable);
 140
 141 #ifdef CONFIG_I2C_MULTI_BUS
 142         bus_initialized[current_bus] = 1;
 143 #endif
 144 }
 145
 146 /*
 147  * i2c_setaddress - Sets the target slave address
 148  * @i2c_addr:   target i2c address
 149  *
 150  * Sets the target slave address.
 151  */
 152 static void i2c_setaddress(unsigned int i2c_addr)
 153 {
 154         writel(i2c_addr, &i2c_regs_p->ic_tar);
 155 }
 156
 157 /*
 158  * i2c_flush_rxfifo - Flushes the i2c RX FIFO
 159  *
 160  * Flushes the i2c RX FIFO
 161  */
 162 static void i2c_flush_rxfifo(void)
 163 {
 164         while (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE)
 165                 readl(&i2c_regs_p->ic_cmd_data);
 166 }
 167
 168 /*
 169  * i2c_wait_for_bb - Waits for bus busy
 170  *
 171  * Waits for bus busy
 172  */
 173 static int i2c_wait_for_bb(void)
 174 {
 175         unsigned long start_time_bb = get_timer(0);
 176
 177         while ((readl(&i2c_regs_p->ic_status) & IC_STATUS_MA) ||
 178                !(readl(&i2c_regs_p->ic_status) & IC_STATUS_TFE)) {
 179
 180                 /* Evaluate timeout */
 181                 if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
 182                         return 1;
 183         }
 184
 185         return 0;
 186 }
 187
 188 /* check parameters for i2c_read and i2c_write */
 189 static int check_params(uint addr, int alen, uchar *buffer, int len)
 190 {
 191         if (buffer == NULL) {
 192                 printf("Buffer is invalid\n");
 193                 return 1;
 194         }
 195
 196         if (alen > 1) {
 197                 printf("addr len %d not supported\n", alen);
 198                 return 1;
 199         }
 200
 201         if (addr + len > 256) {
 202                 printf("address out of range\n");
 203                 return 1;
 204         }
 205
 206         return 0;
 207 }
 208
 209 static int i2c_xfer_init(uchar chip, uint addr)
 210 {
 211         if (i2c_wait_for_bb())
 212                 return 1;
 213
 214         i2c_setaddress(chip);
 215         writel(addr, &i2c_regs_p->ic_cmd_data);
 216
 217         return 0;
 218 }
 219
 220 static int i2c_xfer_finish(void)
 221 {
 222         ulong start_stop_det = get_timer(0);
 223
 224         while (1) {
 225                 if ((readl(&i2c_regs_p->ic_raw_intr_stat) & IC_STOP_DET)) {
 226                         readl(&i2c_regs_p->ic_clr_stop_det);
 227                         break;
 228                 } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
 229                         break;
 230                 }
 231         }
 232
 233         if (i2c_wait_for_bb()) {
 234                 printf("Timed out waiting for bus\n");
 235                 return 1;
 236         }
 237
 238         i2c_flush_rxfifo();
 239
 240         /* Wait for read/write operation to complete on actual memory */
 241         udelay(10000);
 242
 243         return 0;
 244 }
 245
 246 /*
 247  * i2c_read - Read from i2c memory
 248  * @chip:       target i2c address
 249  * @addr:       address to read from
 250  * @alen:
 251  * @buffer:     buffer for read data
 252  * @len:        no of bytes to be read
 253  *
 254  * Read from i2c memory.
 255  */
 256 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 257 {
 258         unsigned long start_time_rx;
 259
 260         if (check_params(addr, alen, buffer, len))
 261                 return 1;
 262
 263         if (i2c_xfer_init(chip, addr))
 264                 return 1;
 265
 266         start_time_rx = get_timer(0);
 267         while (len) {
 268                 if (len == 1)
 269                         writel(IC_CMD | IC_STOP, &i2c_regs_p->ic_cmd_data);
 270                 else
 271                         writel(IC_CMD, &i2c_regs_p->ic_cmd_data);
 272
 273                 if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) {
 274                         *buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data);
 275                         len--;
 276                         start_time_rx = get_timer(0);
 277
 278                 } else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
 279                                 return 1;
 280                 }
 281         }
 282
 283         return i2c_xfer_finish();
 284 }
 285
 286 /*
 287  * i2c_write - Write to i2c memory
 288  * @chip:       target i2c address
 289  * @addr:       address to read from
 290  * @alen:
 291  * @buffer:     buffer for read data
 292  * @len:        no of bytes to be read
 293  *
 294  * Write to i2c memory.
 295  */
 296 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 297 {
 298         int nb = len;
 299         unsigned long start_time_tx;
 300
 301         if (check_params(addr, alen, buffer, len))
 302                 return 1;
 303
 304         if (i2c_xfer_init(chip, addr))
 305                 return 1;
 306
 307         start_time_tx = get_timer(0);
 308         while (len) {
 309                 if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) {
 310                         if (--len == 0)
 311                                 writel(*buffer | IC_STOP, &i2c_regs_p->ic_cmd_data);
 312                         else
 313                                 writel(*buffer, &i2c_regs_p->ic_cmd_data);
 314                         buffer++;
 315                         start_time_tx = get_timer(0);
 316
 317                 } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
 318                                 printf("Timed out. i2c write Failed\n");
 319                                 return 1;
 320                 }
 321         }
 322
 323         return i2c_xfer_finish();
 324 }
 325
 326 /*
 327  * i2c_probe - Probe the i2c chip
 328  */
 329 int i2c_probe(uchar chip)
 330 {
 331         u32 tmp;
 332         int ret;
 333
 334         /*
 335          * Try to read the first location of the chip.
 336          */
 337         ret = i2c_read(chip, 0, 1, (uchar *)&tmp, 1);
 338         if (ret)
 339                 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 340
 341         return ret;
 342 }
 343
 344 #ifdef CONFIG_I2C_MULTI_BUS
 345 int i2c_set_bus_num(unsigned int bus)
 346 {
 347         switch (bus) {
 348         case 0:
 349                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE;
 350                 break;
 351 #ifdef CONFIG_SYS_I2C_BASE1
 352         case 1:
 353                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE1;
 354                 break;
 355 #endif
 356 #ifdef CONFIG_SYS_I2C_BASE2
 357         case 2:
 358                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE2;
 359                 break;
 360 #endif
 361 #ifdef CONFIG_SYS_I2C_BASE3
 362         case 3:
 363                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE3;
 364                 break;
 365 #endif
 366 #ifdef CONFIG_SYS_I2C_BASE4
 367         case 4:
 368                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE4;
 369                 break;
 370 #endif
 371 #ifdef CONFIG_SYS_I2C_BASE5
 372         case 5:
 373                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE5;
 374                 break;
 375 #endif
 376 #ifdef CONFIG_SYS_I2C_BASE6
 377         case 6:
 378                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE6;
 379                 break;
 380 #endif
 381 #ifdef CONFIG_SYS_I2C_BASE7
 382         case 7:
 383                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE7;
 384                 break;
 385 #endif
 386 #ifdef CONFIG_SYS_I2C_BASE8
 387         case 8:
 388                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE8;
 389                 break;
 390 #endif
 391 #ifdef CONFIG_SYS_I2C_BASE9
 392         case 9:
 393                 i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE9;
 394                 break;
 395 #endif
 396         default:
 397                 printf("Bad bus: %d\n", bus);
 398                 return -1;
 399         }
 400
 401         current_bus = bus;
 402
 403         if (!bus_initialized[current_bus])
 404                 i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 405
 406         return 0;
 407 }
 408
 409 int i2c_get_bus_num(void)
 410 {
 411         return current_bus;
 412 }
 413 #endif