drivers/i2c/rk_i2c.c

   1 /*
   2  * (C) Copyright 2015 Google, Inc
   3  *
   4  * (C) Copyright 2008-2014 Rockchip Electronics
   5  * Peter, Software Engineering, <superpeter.cai@gmail.com>.
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <clk.h>
  12 #include <dm.h>
  13 #include <errno.h>
  14 #include <i2c.h>
  15 #include <asm/io.h>
  16 #include <asm/arch/clock.h>
  17 #include <asm/arch/i2c.h>
  18 #include <asm/arch/periph.h>
  19 #include <dm/pinctrl.h>
  20 #include <linux/sizes.h>
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 /* i2c timerout */
  25 #define I2C_TIMEOUT_MS          100
  26 #define I2C_RETRY_COUNT         3
  27
  28 /* rk i2c fifo max transfer bytes */
  29 #define RK_I2C_FIFO_SIZE        32
  30
  31 struct rk_i2c {
  32         struct clk clk;
  33         struct i2c_regs *regs;
  34         unsigned int speed;
  35 };
  36
  37 static inline void rk_i2c_get_div(int div, int *divh, int *divl)
  38 {
  39         *divl = div / 2;
  40         if (div % 2 == 0)
  41                 *divh = div / 2;
  42         else
  43                 *divh = DIV_ROUND_UP(div, 2);
  44 }
  45
  46 /*
  47  * SCL Divisor = 8 * (CLKDIVL+1 + CLKDIVH+1)
  48  * SCL = PCLK / SCLK Divisor
  49  * i2c_rate = PCLK
  50  */
  51 static void rk_i2c_set_clk(struct rk_i2c *i2c, uint32_t scl_rate)
  52 {
  53         uint32_t i2c_rate;
  54         int div, divl, divh;
  55
  56         /* First get i2c rate from pclk */
  57         i2c_rate = clk_get_rate(&i2c->clk);
  58
  59         div = DIV_ROUND_UP(i2c_rate, scl_rate * 8) - 2;
  60         divh = 0;
  61         divl = 0;
  62         if (div >= 0)
  63                 rk_i2c_get_div(div, &divh, &divl);
  64         writel(I2C_CLKDIV_VAL(divl, divh), &i2c->regs->clkdiv);
  65
  66         debug("rk_i2c_set_clk: i2c rate = %d, scl rate = %d\n", i2c_rate,
  67               scl_rate);
  68         debug("set i2c clk div = %d, divh = %d, divl = %d\n", div, divh, divl);
  69         debug("set clk(I2C_CLKDIV: 0x%08x)\n", readl(&i2c->regs->clkdiv));
  70 }
  71
  72 static void rk_i2c_show_regs(struct i2c_regs *regs)
  73 {
  74 #ifdef DEBUG
  75         uint i;
  76
  77         debug("i2c_con: 0x%08x\n", readl(&regs->con));
  78         debug("i2c_clkdiv: 0x%08x\n", readl(&regs->clkdiv));
  79         debug("i2c_mrxaddr: 0x%08x\n", readl(&regs->mrxaddr));
  80         debug("i2c_mrxraddR: 0x%08x\n", readl(&regs->mrxraddr));
  81         debug("i2c_mtxcnt: 0x%08x\n", readl(&regs->mtxcnt));
  82         debug("i2c_mrxcnt: 0x%08x\n", readl(&regs->mrxcnt));
  83         debug("i2c_ien: 0x%08x\n", readl(&regs->ien));
  84         debug("i2c_ipd: 0x%08x\n", readl(&regs->ipd));
  85         debug("i2c_fcnt: 0x%08x\n", readl(&regs->fcnt));
  86         for (i = 0; i < 8; i++)
  87                 debug("i2c_txdata%d: 0x%08x\n", i, readl(&regs->txdata[i]));
  88         for (i = 0; i < 8; i++)
  89                 debug("i2c_rxdata%d: 0x%08x\n", i, readl(&regs->rxdata[i]));
  90 #endif
  91 }
  92
  93 static int rk_i2c_send_start_bit(struct rk_i2c *i2c)
  94 {
  95         struct i2c_regs *regs = i2c->regs;
  96         ulong start;
  97
  98         debug("I2c Send Start bit.\n");
  99         writel(I2C_IPD_ALL_CLEAN, &regs->ipd);
 100
 101         writel(I2C_CON_EN | I2C_CON_START, &regs->con);
 102         writel(I2C_STARTIEN, &regs->ien);
 103
 104         start = get_timer(0);
 105         while (1) {
 106                 if (readl(&regs->ipd) & I2C_STARTIPD) {
 107                         writel(I2C_STARTIPD, &regs->ipd);
 108                         break;
 109                 }
 110                 if (get_timer(start) > I2C_TIMEOUT_MS) {
 111                         debug("I2C Send Start Bit Timeout\n");
 112                         rk_i2c_show_regs(regs);
 113                         return -ETIMEDOUT;
 114                 }
 115                 udelay(1);
 116         }
 117
 118         return 0;
 119 }
 120
 121 static int rk_i2c_send_stop_bit(struct rk_i2c *i2c)
 122 {
 123         struct i2c_regs *regs = i2c->regs;
 124         ulong start;
 125
 126         debug("I2c Send Stop bit.\n");
 127         writel(I2C_IPD_ALL_CLEAN, &regs->ipd);
 128
 129         writel(I2C_CON_EN | I2C_CON_STOP, &regs->con);
 130         writel(I2C_CON_STOP, &regs->ien);
 131
 132         start = get_timer(0);
 133         while (1) {
 134                 if (readl(&regs->ipd) & I2C_STOPIPD) {
 135                         writel(I2C_STOPIPD, &regs->ipd);
 136                         break;
 137                 }
 138                 if (get_timer(start) > I2C_TIMEOUT_MS) {
 139                         debug("I2C Send Start Bit Timeout\n");
 140                         rk_i2c_show_regs(regs);
 141                         return -ETIMEDOUT;
 142                 }
 143                 udelay(1);
 144         }
 145
 146         return 0;
 147 }
 148
 149 static inline void rk_i2c_disable(struct rk_i2c *i2c)
 150 {
 151         writel(0, &i2c->regs->con);
 152 }
 153
 154 static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
 155                        uchar *buf, uint b_len)
 156 {
 157         struct i2c_regs *regs = i2c->regs;
 158         uchar *pbuf = buf;
 159         uint bytes_remain_len = b_len;
 160         uint bytes_xferred = 0;
 161         uint words_xferred = 0;
 162         ulong start;
 163         uint con = 0;
 164         uint rxdata;
 165         uint i, j;
 166         int err;
 167         bool snd_chunk = false;
 168
 169         debug("rk_i2c_read: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
 170               chip, reg, r_len, b_len);
 171
 172         err = rk_i2c_send_start_bit(i2c);
 173         if (err)
 174                 return err;
 175
 176         writel(I2C_MRXADDR_SET(1, chip << 1 | 1), &regs->mrxaddr);
 177         if (r_len == 0) {
 178                 writel(0, &regs->mrxraddr);
 179         } else if (r_len < 4) {
 180                 writel(I2C_MRXRADDR_SET(r_len, reg), &regs->mrxraddr);
 181         } else {
 182                 debug("I2C Read: addr len %d not supported\n", r_len);
 183                 return -EIO;
 184         }
 185
 186         while (bytes_remain_len) {
 187                 if (bytes_remain_len > RK_I2C_FIFO_SIZE) {
 188                         con = I2C_CON_EN;
 189                         bytes_xferred = 32;
 190                 } else {
 191                         /*
 192                          * The hw can read up to 32 bytes at a time. If we need
 193                          * more than one chunk, send an ACK after the last byte.
 194                          */
 195                         con = I2C_CON_EN | I2C_CON_LASTACK;
 196                         bytes_xferred = bytes_remain_len;
 197                 }
 198                 words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
 199
 200                 /*
 201                  * make sure we are in plain RX mode if we read a second chunk
 202                  */
 203                 if (snd_chunk)
 204                         con |= I2C_CON_MOD(I2C_MODE_RX);
 205                 else
 206                         con |= I2C_CON_MOD(I2C_MODE_TRX);
 207
 208                 writel(con, &regs->con);
 209                 writel(bytes_xferred, &regs->mrxcnt);
 210                 writel(I2C_MBRFIEN | I2C_NAKRCVIEN, &regs->ien);
 211
 212                 start = get_timer(0);
 213                 while (1) {
 214                         if (readl(&regs->ipd) & I2C_NAKRCVIPD) {
 215                                 writel(I2C_NAKRCVIPD, &regs->ipd);
 216                                 err = -EREMOTEIO;
 217                         }
 218                         if (readl(&regs->ipd) & I2C_MBRFIPD) {
 219                                 writel(I2C_MBRFIPD, &regs->ipd);
 220                                 break;
 221                         }
 222                         if (get_timer(start) > I2C_TIMEOUT_MS) {
 223                                 debug("I2C Read Data Timeout\n");
 224                                 err =  -ETIMEDOUT;
 225                                 rk_i2c_show_regs(regs);
 226                                 goto i2c_exit;
 227                         }
 228                         udelay(1);
 229                 }
 230
 231                 for (i = 0; i < words_xferred; i++) {
 232                         rxdata = readl(&regs->rxdata[i]);
 233                         debug("I2c Read RXDATA[%d] = 0x%x\n", i, rxdata);
 234                         for (j = 0; j < 4; j++) {
 235                                 if ((i * 4 + j) == bytes_xferred)
 236                                         break;
 237                                 *pbuf++ = (rxdata >> (j * 8)) & 0xff;
 238                         }
 239                 }
 240
 241                 bytes_remain_len -= bytes_xferred;
 242                 snd_chunk = true;
 243                 debug("I2C Read bytes_remain_len %d\n", bytes_remain_len);
 244         }
 245
 246 i2c_exit:
 247         rk_i2c_send_stop_bit(i2c);
 248         rk_i2c_disable(i2c);
 249
 250         return err;
 251 }
 252
 253 static int rk_i2c_write(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
 254                         uchar *buf, uint b_len)
 255 {
 256         struct i2c_regs *regs = i2c->regs;
 257         int err;
 258         uchar *pbuf = buf;
 259         uint bytes_remain_len = b_len + r_len + 1;
 260         uint bytes_xferred = 0;
 261         uint words_xferred = 0;
 262         ulong start;
 263         uint txdata;
 264         uint i, j;
 265
 266         debug("rk_i2c_write: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
 267               chip, reg, r_len, b_len);
 268         err = rk_i2c_send_start_bit(i2c);
 269         if (err)
 270                 return err;
 271
 272         while (bytes_remain_len) {
 273                 if (bytes_remain_len > RK_I2C_FIFO_SIZE)
 274                         bytes_xferred = RK_I2C_FIFO_SIZE;
 275                 else
 276                         bytes_xferred = bytes_remain_len;
 277                 words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
 278
 279                 for (i = 0; i < words_xferred; i++) {
 280                         txdata = 0;
 281                         for (j = 0; j < 4; j++) {
 282                                 if ((i * 4 + j) == bytes_xferred)
 283                                         break;
 284
 285                                 if (i == 0 && j == 0 && pbuf == buf) {
 286                                         txdata |= (chip << 1);
 287                                 } else if (i == 0 && j <= r_len && pbuf == buf) {
 288                                         txdata |= (reg &
 289                                                 (0xff << ((j - 1) * 8))) << 8;
 290                                 } else {
 291                                         txdata |= (*pbuf++)<<(j * 8);
 292                                 }
 293                         }
 294                         writel(txdata, &regs->txdata[i]);
 295                         debug("I2c Write TXDATA[%d] = 0x%08x\n", i, txdata);
 296                 }
 297
 298                 writel(I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TX), &regs->con);
 299                 writel(bytes_xferred, &regs->mtxcnt);
 300                 writel(I2C_MBTFIEN | I2C_NAKRCVIEN, &regs->ien);
 301
 302                 start = get_timer(0);
 303                 while (1) {
 304                         if (readl(&regs->ipd) & I2C_NAKRCVIPD) {
 305                                 writel(I2C_NAKRCVIPD, &regs->ipd);
 306                                 err = -EREMOTEIO;
 307                         }
 308                         if (readl(&regs->ipd) & I2C_MBTFIPD) {
 309                                 writel(I2C_MBTFIPD, &regs->ipd);
 310                                 break;
 311                         }
 312                         if (get_timer(start) > I2C_TIMEOUT_MS) {
 313                                 debug("I2C Write Data Timeout\n");
 314                                 err =  -ETIMEDOUT;
 315                                 rk_i2c_show_regs(regs);
 316                                 goto i2c_exit;
 317                         }
 318                         udelay(1);
 319                 }
 320
 321                 bytes_remain_len -= bytes_xferred;
 322                 debug("I2C Write bytes_remain_len %d\n", bytes_remain_len);
 323         }
 324
 325 i2c_exit:
 326         rk_i2c_send_stop_bit(i2c);
 327         rk_i2c_disable(i2c);
 328
 329         return err;
 330 }
 331
 332 static int rockchip_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 333                              int nmsgs)
 334 {
 335         struct rk_i2c *i2c = dev_get_priv(bus);
 336         int ret;
 337
 338         debug("i2c_xfer: %d messages\n", nmsgs);
 339         for (; nmsgs > 0; nmsgs--, msg++) {
 340                 debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
 341                 if (msg->flags & I2C_M_RD) {
 342                         ret = rk_i2c_read(i2c, msg->addr, 0, 0, msg->buf,
 343                                           msg->len);
 344                 } else {
 345                         ret = rk_i2c_write(i2c, msg->addr, 0, 0, msg->buf,
 346                                            msg->len);
 347                 }
 348                 if (ret) {
 349                         debug("i2c_write: error sending\n");
 350                         return -EREMOTEIO;
 351                 }
 352         }
 353
 354         return 0;
 355 }
 356
 357 int rockchip_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 358 {
 359         struct rk_i2c *i2c = dev_get_priv(bus);
 360
 361         rk_i2c_set_clk(i2c, speed);
 362
 363         return 0;
 364 }
 365
 366 static int rockchip_i2c_ofdata_to_platdata(struct udevice *bus)
 367 {
 368         struct rk_i2c *priv = dev_get_priv(bus);
 369         int ret;
 370
 371         ret = clk_get_by_index(bus, 0, &priv->clk);
 372         if (ret < 0) {
 373                 debug("%s: Could not get clock for %s: %d\n", __func__,
 374                       bus->name, ret);
 375                 return ret;
 376         }
 377
 378         return 0;
 379 }
 380
 381 static int rockchip_i2c_probe(struct udevice *bus)
 382 {
 383         struct rk_i2c *priv = dev_get_priv(bus);
 384
 385         priv->regs = dev_read_addr_ptr(bus);
 386
 387         return 0;
 388 }
 389
 390 static const struct dm_i2c_ops rockchip_i2c_ops = {
 391         .xfer           = rockchip_i2c_xfer,
 392         .set_bus_speed  = rockchip_i2c_set_bus_speed,
 393 };
 394
 395 static const struct udevice_id rockchip_i2c_ids[] = {
 396         { .compatible = "rockchip,rk3066-i2c" },
 397         { .compatible = "rockchip,rk3188-i2c" },
 398         { .compatible = "rockchip,rk3288-i2c" },
 399         { .compatible = "rockchip,rk3328-i2c" },
 400         { .compatible = "rockchip,rk3399-i2c" },
 401         { }
 402 };
 403
 404 U_BOOT_DRIVER(i2c_rockchip) = {
 405         .name   = "i2c_rockchip",
 406         .id     = UCLASS_I2C,
 407         .of_match = rockchip_i2c_ids,
 408         .ofdata_to_platdata = rockchip_i2c_ofdata_to_platdata,
 409         .probe  = rockchip_i2c_probe,
 410         .priv_auto_alloc_size = sizeof(struct rk_i2c),
 411         .ops    = &rockchip_i2c_ops,
 412 };