drivers/i2c/sh_sh7734_i2c.c

   1 /*
   2  * Copyright (C) 2012 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
   3  * Copyright (C) 2012 Renesas Solutions Corp.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  *
   7  * NOTE: This driver should be converted to driver model before June 2017.
   8  * Please see doc/driver-model/i2c-howto.txt for instructions.
   9  */
  10
  11 #include <common.h>
  12 #include <i2c.h>
  13 #include <asm/io.h>
  14
  15 struct sh_i2c {
  16         u8 iccr1;
  17         u8 iccr2;
  18         u8 icmr;
  19         u8 icier;
  20         u8 icsr;
  21         u8 sar;
  22         u8 icdrt;
  23         u8 icdrr;
  24         u8 nf2cyc;
  25         u8 __pad0;
  26         u8 __pad1;
  27 };
  28
  29 static struct sh_i2c *base;
  30 static u8 iccr1_cks, nf2cyc;
  31
  32 /* ICCR1 */
  33 #define SH_I2C_ICCR1_ICE        (1 << 7)
  34 #define SH_I2C_ICCR1_RCVD       (1 << 6)
  35 #define SH_I2C_ICCR1_MST        (1 << 5)
  36 #define SH_I2C_ICCR1_TRS        (1 << 4)
  37 #define SH_I2C_ICCR1_MTRS       \
  38         (SH_I2C_ICCR1_MST | SH_I2C_ICCR1_TRS)
  39
  40 /* ICCR1 */
  41 #define SH_I2C_ICCR2_BBSY       (1 << 7)
  42 #define SH_I2C_ICCR2_SCP        (1 << 6)
  43 #define SH_I2C_ICCR2_SDAO       (1 << 5)
  44 #define SH_I2C_ICCR2_SDAOP      (1 << 4)
  45 #define SH_I2C_ICCR2_SCLO       (1 << 3)
  46 #define SH_I2C_ICCR2_IICRST     (1 << 1)
  47
  48 #define SH_I2C_ICIER_TIE        (1 << 7)
  49 #define SH_I2C_ICIER_TEIE       (1 << 6)
  50 #define SH_I2C_ICIER_RIE        (1 << 5)
  51 #define SH_I2C_ICIER_NAKIE      (1 << 4)
  52 #define SH_I2C_ICIER_STIE       (1 << 3)
  53 #define SH_I2C_ICIER_ACKE       (1 << 2)
  54 #define SH_I2C_ICIER_ACKBR      (1 << 1)
  55 #define SH_I2C_ICIER_ACKBT      (1 << 0)
  56
  57 #define SH_I2C_ICSR_TDRE        (1 << 7)
  58 #define SH_I2C_ICSR_TEND        (1 << 6)
  59 #define SH_I2C_ICSR_RDRF        (1 << 5)
  60 #define SH_I2C_ICSR_NACKF       (1 << 4)
  61 #define SH_I2C_ICSR_STOP        (1 << 3)
  62 #define SH_I2C_ICSR_ALOVE       (1 << 2)
  63 #define SH_I2C_ICSR_AAS         (1 << 1)
  64 #define SH_I2C_ICSR_ADZ         (1 << 0)
  65
  66 #define IRQ_WAIT 1000
  67
  68 static void sh_i2c_send_stop(struct sh_i2c *base)
  69 {
  70         clrbits_8(&base->iccr2, SH_I2C_ICCR2_BBSY | SH_I2C_ICCR2_SCP);
  71 }
  72
  73 static int check_icsr_bits(struct sh_i2c *base, u8 bits)
  74 {
  75         int i;
  76
  77         for (i = 0; i < IRQ_WAIT; i++) {
  78                 if (bits & readb(&base->icsr))
  79                         return 0;
  80                 udelay(10);
  81         }
  82
  83         return 1;
  84 }
  85
  86 static int check_stop(struct sh_i2c *base)
  87 {
  88         int ret = check_icsr_bits(base, SH_I2C_ICSR_STOP);
  89         clrbits_8(&base->icsr, SH_I2C_ICSR_STOP);
  90
  91         return ret;
  92 }
  93
  94 static int check_tend(struct sh_i2c *base, int stop)
  95 {
  96         int ret = check_icsr_bits(base, SH_I2C_ICSR_TEND);
  97
  98         if (stop) {
  99                 clrbits_8(&base->icsr, SH_I2C_ICSR_STOP);
 100                 sh_i2c_send_stop(base);
 101         }
 102
 103         clrbits_8(&base->icsr, SH_I2C_ICSR_TEND);
 104         return ret;
 105 }
 106
 107 static int check_tdre(struct sh_i2c *base)
 108 {
 109         return check_icsr_bits(base, SH_I2C_ICSR_TDRE);
 110 }
 111
 112 static int check_rdrf(struct sh_i2c *base)
 113 {
 114         return check_icsr_bits(base, SH_I2C_ICSR_RDRF);
 115 }
 116
 117 static int check_bbsy(struct sh_i2c *base)
 118 {
 119         int i;
 120
 121         for (i = 0 ; i < IRQ_WAIT ; i++) {
 122                 if (!(SH_I2C_ICCR2_BBSY & readb(&base->iccr2)))
 123                         return 0;
 124                 udelay(10);
 125         }
 126         return 1;
 127 }
 128
 129 static int check_ackbr(struct sh_i2c *base)
 130 {
 131         int i;
 132
 133         for (i = 0 ; i < IRQ_WAIT ; i++) {
 134                 if (!(SH_I2C_ICIER_ACKBR & readb(&base->icier)))
 135                         return 0;
 136                 udelay(10);
 137         }
 138
 139         return 1;
 140 }
 141
 142 static void sh_i2c_reset(struct sh_i2c *base)
 143 {
 144         setbits_8(&base->iccr2, SH_I2C_ICCR2_IICRST);
 145
 146         udelay(100);
 147
 148         clrbits_8(&base->iccr2, SH_I2C_ICCR2_IICRST);
 149 }
 150
 151 static int i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg)
 152 {
 153         if (check_bbsy(base)) {
 154                 puts("i2c bus busy\n");
 155                 goto fail;
 156         }
 157
 158         setbits_8(&base->iccr1, SH_I2C_ICCR1_MTRS);
 159         clrsetbits_8(&base->iccr2, SH_I2C_ICCR2_SCP, SH_I2C_ICCR2_BBSY);
 160
 161         writeb((id << 1), &base->icdrt);
 162
 163         if (check_tend(base, 0)) {
 164                 puts("TEND check fail...\n");
 165                 goto fail;
 166         }
 167
 168         if (check_ackbr(base)) {
 169                 check_tend(base, 0);
 170                 sh_i2c_send_stop(base);
 171                 goto fail;
 172         }
 173
 174         writeb(reg, &base->icdrt);
 175
 176         if (check_tdre(base)) {
 177                 puts("TDRE check fail...\n");
 178                 goto fail;
 179         }
 180
 181         if (check_tend(base, 0)) {
 182                 puts("TEND check fail...\n");
 183                 goto fail;
 184         }
 185
 186         return 0;
 187 fail:
 188
 189         return 1;
 190 }
 191
 192 static int
 193 i2c_raw_write(struct sh_i2c *base, u8 id, u8 reg, u8 *val, int size)
 194 {
 195         int i;
 196
 197         if (i2c_set_addr(base, id, reg)) {
 198                 puts("Fail set slave address\n");
 199                 return 1;
 200         }
 201
 202         for (i = 0; i < size; i++) {
 203                 writeb(val[i], &base->icdrt);
 204                 check_tdre(base);
 205         }
 206
 207         check_tend(base, 1);
 208         check_stop(base);
 209
 210         udelay(100);
 211
 212         clrbits_8(&base->iccr1, SH_I2C_ICCR1_MTRS);
 213         clrbits_8(&base->icsr, SH_I2C_ICSR_TDRE);
 214         sh_i2c_reset(base);
 215
 216         return 0;
 217 }
 218
 219 static u8 i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg)
 220 {
 221         u8 ret = 0;
 222
 223         if (i2c_set_addr(base, id, reg)) {
 224                 puts("Fail set slave address\n");
 225                 goto fail;
 226         }
 227
 228         clrsetbits_8(&base->iccr2, SH_I2C_ICCR2_SCP, SH_I2C_ICCR2_BBSY);
 229         writeb((id << 1) | 1, &base->icdrt);
 230
 231         if (check_tend(base, 0))
 232                 puts("TDRE check fail...\n");
 233
 234         clrsetbits_8(&base->iccr1, SH_I2C_ICCR1_TRS, SH_I2C_ICCR1_MST);
 235         clrbits_8(&base->icsr, SH_I2C_ICSR_TDRE);
 236         setbits_8(&base->icier, SH_I2C_ICIER_ACKBT);
 237         setbits_8(&base->iccr1, SH_I2C_ICCR1_RCVD);
 238
 239         /* read data (dummy) */
 240         ret = readb(&base->icdrr);
 241
 242         if (check_rdrf(base)) {
 243                 puts("check RDRF error\n");
 244                 goto fail;
 245         }
 246
 247         clrbits_8(&base->icsr, SH_I2C_ICSR_STOP);
 248         udelay(1000);
 249
 250         sh_i2c_send_stop(base);
 251
 252         if (check_stop(base)) {
 253                 puts("check STOP error\n");
 254                 goto fail;
 255         }
 256
 257         clrbits_8(&base->iccr1, SH_I2C_ICCR1_MTRS);
 258         clrbits_8(&base->icsr, SH_I2C_ICSR_TDRE);
 259
 260         /* data read */
 261         ret = readb(&base->icdrr);
 262
 263 fail:
 264         clrbits_8(&base->iccr1, SH_I2C_ICCR1_RCVD);
 265
 266         return ret;
 267 }
 268
 269 #ifdef CONFIG_I2C_MULTI_BUS
 270 static unsigned int current_bus;
 271
 272 /**
 273  * i2c_set_bus_num - change active I2C bus
 274  *      @bus: bus index, zero based
 275  *      @returns: 0 on success, non-0 on failure
 276  */
 277 int i2c_set_bus_num(unsigned int bus)
 278 {
 279         switch (bus) {
 280         case 0:
 281                 base = (void *)CONFIG_SH_I2C_BASE0;
 282                 break;
 283         case 1:
 284                 base = (void *)CONFIG_SH_I2C_BASE1;
 285                 break;
 286         default:
 287                 printf("Bad bus: %d\n", bus);
 288                 return -1;
 289         }
 290
 291         current_bus = bus;
 292
 293         return 0;
 294 }
 295
 296 /**
 297  * i2c_get_bus_num - returns index of active I2C bus
 298  */
 299 unsigned int i2c_get_bus_num(void)
 300 {
 301         return current_bus;
 302 }
 303 #endif
 304
 305 void i2c_init(int speed, int slaveaddr)
 306 {
 307 #ifdef CONFIG_I2C_MULTI_BUS
 308         current_bus = 0;
 309 #endif
 310         base = (struct sh_i2c *)CONFIG_SH_I2C_BASE0;
 311
 312         if (speed == 400000)
 313                 iccr1_cks = 0x07;
 314         else
 315                 iccr1_cks = 0x0F;
 316
 317         nf2cyc = 1;
 318
 319         /* Reset */
 320         sh_i2c_reset(base);
 321
 322         /* ICE enable and set clock */
 323         writeb(SH_I2C_ICCR1_ICE | iccr1_cks, &base->iccr1);
 324         writeb(nf2cyc, &base->nf2cyc);
 325 }
 326
 327 /*
 328  * i2c_read: - Read multiple bytes from an i2c device
 329  *
 330  * The higher level routines take into account that this function is only
 331  * called with len < page length of the device (see configuration file)
 332  *
 333  * @chip:   address of the chip which is to be read
 334  * @addr:   i2c data address within the chip
 335  * @alen:   length of the i2c data address (1..2 bytes)
 336  * @buffer: where to write the data
 337  * @len:    how much byte do we want to read
 338  * @return: 0 in case of success
 339  */
 340 int i2c_read(u8 chip, u32 addr, int alen, u8 *buffer, int len)
 341 {
 342         int i = 0;
 343         for (i = 0; i < len; i++)
 344                 buffer[i] = i2c_raw_read(base, chip, addr + i);
 345
 346         return 0;
 347 }
 348
 349 /*
 350  * i2c_write: -  Write multiple bytes to an i2c device
 351  *
 352  * The higher level routines take into account that this function is only
 353  * called with len < page length of the device (see configuration file)
 354  *
 355  * @chip:   address of the chip which is to be written
 356  * @addr:   i2c data address within the chip
 357  * @alen:   length of the i2c data address (1..2 bytes)
 358  * @buffer: where to find the data to be written
 359  * @len:    how much byte do we want to read
 360  * @return: 0 in case of success
 361  */
 362 int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len)
 363 {
 364         return i2c_raw_write(base, chip, addr, buffer, len);
 365 }
 366
 367 /*
 368  * i2c_probe: - Test if a chip answers for a given i2c address
 369  *
 370  * @chip:   address of the chip which is searched for
 371  * @return: 0 if a chip was found, -1 otherwhise
 372  */
 373 int i2c_probe(u8 chip)
 374 {
 375         u8 byte;
 376         return i2c_read(chip, 0, 0, &byte, 1);
 377 }