Pileus Git - ~andy/linux/blob - drivers/i2c/busses/i2c-mv64xxx.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, and Orion SoC family).
   4  *
   5  * Author: Mark A. Greer <mgreer@mvista.com>
   6  *
   7  * 2005 (c) MontaVista, Software, Inc.  This file is licensed under
   8  * the terms of the GNU General Public License version 2.  This program
   9  * is licensed "as is" without any warranty of any kind, whether express
  10  * or implied.
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/module.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/i2c.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/mv643xx_i2c.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/io.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/of_irq.h>
  24 #include <linux/clk.h>
  25 #include <linux/err.h>
  26 #include <linux/delay.h>
  27
  28 #define MV64XXX_I2C_ADDR_ADDR(val)                      ((val & 0x7f) << 1)
  29 #define MV64XXX_I2C_BAUD_DIV_N(val)                     (val & 0x7)
  30 #define MV64XXX_I2C_BAUD_DIV_M(val)                     ((val & 0xf) << 3)
  31
  32 #define MV64XXX_I2C_REG_CONTROL_ACK                     0x00000004
  33 #define MV64XXX_I2C_REG_CONTROL_IFLG                    0x00000008
  34 #define MV64XXX_I2C_REG_CONTROL_STOP                    0x00000010
  35 #define MV64XXX_I2C_REG_CONTROL_START                   0x00000020
  36 #define MV64XXX_I2C_REG_CONTROL_TWSIEN                  0x00000040
  37 #define MV64XXX_I2C_REG_CONTROL_INTEN                   0x00000080
  38
  39 /* Ctlr status values */
  40 #define MV64XXX_I2C_STATUS_BUS_ERR                      0x00
  41 #define MV64XXX_I2C_STATUS_MAST_START                   0x08
  42 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START            0x10
  43 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK             0x18
  44 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK          0x20
  45 #define MV64XXX_I2C_STATUS_MAST_WR_ACK                  0x28
  46 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK               0x30
  47 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB                0x38
  48 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK             0x40
  49 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK          0x48
  50 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK             0x50
  51 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK          0x58
  52 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK           0xd0
  53 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK        0xd8
  54 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK           0xe0
  55 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK        0xe8
  56 #define MV64XXX_I2C_STATUS_NO_STATUS                    0xf8
  57
  58 /* Register defines (I2C bridge) */
  59 #define MV64XXX_I2C_REG_TX_DATA_LO                      0xc0
  60 #define MV64XXX_I2C_REG_TX_DATA_HI                      0xc4
  61 #define MV64XXX_I2C_REG_RX_DATA_LO                      0xc8
  62 #define MV64XXX_I2C_REG_RX_DATA_HI                      0xcc
  63 #define MV64XXX_I2C_REG_BRIDGE_CONTROL                  0xd0
  64 #define MV64XXX_I2C_REG_BRIDGE_STATUS                   0xd4
  65 #define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE               0xd8
  66 #define MV64XXX_I2C_REG_BRIDGE_INTR_MASK                0xdC
  67 #define MV64XXX_I2C_REG_BRIDGE_TIMING                   0xe0
  68
  69 /* Bridge Control values */
  70 #define MV64XXX_I2C_BRIDGE_CONTROL_WR                   0x00000001
  71 #define MV64XXX_I2C_BRIDGE_CONTROL_RD                   0x00000002
  72 #define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT           2
  73 #define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT             0x00001000
  74 #define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT        13
  75 #define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT        16
  76 #define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE               0x00080000
  77
  78 /* Bridge Status values */
  79 #define MV64XXX_I2C_BRIDGE_STATUS_ERROR                 0x00000001
  80 #define MV64XXX_I2C_STATUS_OFFLOAD_ERROR                0xf0000001
  81 #define MV64XXX_I2C_STATUS_OFFLOAD_OK                   0xf0000000
  82
  83
  84 /* Driver states */
  85 enum {
  86         MV64XXX_I2C_STATE_INVALID,
  87         MV64XXX_I2C_STATE_IDLE,
  88         MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
  89         MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
  90         MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
  91         MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
  92         MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
  93         MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
  94 };
  95
  96 /* Driver actions */
  97 enum {
  98         MV64XXX_I2C_ACTION_INVALID,
  99         MV64XXX_I2C_ACTION_CONTINUE,
 100         MV64XXX_I2C_ACTION_SEND_START,
 101         MV64XXX_I2C_ACTION_SEND_RESTART,
 102         MV64XXX_I2C_ACTION_OFFLOAD_RESTART,
 103         MV64XXX_I2C_ACTION_SEND_ADDR_1,
 104         MV64XXX_I2C_ACTION_SEND_ADDR_2,
 105         MV64XXX_I2C_ACTION_SEND_DATA,
 106         MV64XXX_I2C_ACTION_RCV_DATA,
 107         MV64XXX_I2C_ACTION_RCV_DATA_STOP,
 108         MV64XXX_I2C_ACTION_SEND_STOP,
 109         MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP,
 110 };
 111
 112 struct mv64xxx_i2c_regs {
 113         u8      addr;
 114         u8      ext_addr;
 115         u8      data;
 116         u8      control;
 117         u8      status;
 118         u8      clock;
 119         u8      soft_reset;
 120 };
 121
 122 struct mv64xxx_i2c_data {
 123         struct i2c_msg          *msgs;
 124         int                     num_msgs;
 125         int                     irq;
 126         u32                     state;
 127         u32                     action;
 128         u32                     aborting;
 129         u32                     cntl_bits;
 130         void __iomem            *reg_base;
 131         struct mv64xxx_i2c_regs reg_offsets;
 132         u32                     addr1;
 133         u32                     addr2;
 134         u32                     bytes_left;
 135         u32                     byte_posn;
 136         u32                     send_stop;
 137         u32                     block;
 138         int                     rc;
 139         u32                     freq_m;
 140         u32                     freq_n;
 141 #if defined(CONFIG_HAVE_CLK)
 142         struct clk              *clk;
 143 #endif
 144         wait_queue_head_t       waitq;
 145         spinlock_t              lock;
 146         struct i2c_msg          *msg;
 147         struct i2c_adapter      adapter;
 148         bool                    offload_enabled;
 149 /* 5us delay in order to avoid repeated start timing violation */
 150         bool                    errata_delay;
 151 };
 152
 153 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
 154         .addr           = 0x00,
 155         .ext_addr       = 0x10,
 156         .data           = 0x04,
 157         .control        = 0x08,
 158         .status         = 0x0c,
 159         .clock          = 0x0c,
 160         .soft_reset     = 0x1c,
 161 };
 162
 163 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = {
 164         .addr           = 0x00,
 165         .ext_addr       = 0x04,
 166         .data           = 0x08,
 167         .control        = 0x0c,
 168         .status         = 0x10,
 169         .clock          = 0x14,
 170         .soft_reset     = 0x18,
 171 };
 172
 173 static void
 174 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
 175         struct i2c_msg *msg)
 176 {
 177         u32     dir = 0;
 178
 179         drv_data->msg = msg;
 180         drv_data->byte_posn = 0;
 181         drv_data->bytes_left = msg->len;
 182         drv_data->aborting = 0;
 183         drv_data->rc = 0;
 184         drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
 185                 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
 186
 187         if (msg->flags & I2C_M_RD)
 188                 dir = 1;
 189
 190         if (msg->flags & I2C_M_TEN) {
 191                 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
 192                 drv_data->addr2 = (u32)msg->addr & 0xff;
 193         } else {
 194                 drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir;
 195                 drv_data->addr2 = 0;
 196         }
 197 }
 198
 199 static int mv64xxx_i2c_offload_msg(struct mv64xxx_i2c_data *drv_data)
 200 {
 201         unsigned long data_reg_hi = 0;
 202         unsigned long data_reg_lo = 0;
 203         unsigned long ctrl_reg;
 204         struct i2c_msg *msg = drv_data->msgs;
 205
 206         if (!drv_data->offload_enabled)
 207                 return -EOPNOTSUPP;
 208
 209         drv_data->msg = msg;
 210         drv_data->byte_posn = 0;
 211         drv_data->bytes_left = msg->len;
 212         drv_data->aborting = 0;
 213         drv_data->rc = 0;
 214         /* Only regular transactions can be offloaded */
 215         if ((msg->flags & ~(I2C_M_TEN | I2C_M_RD)) != 0)
 216                 return -EINVAL;
 217
 218         /* Only 1-8 byte transfers can be offloaded */
 219         if (msg->len < 1 || msg->len > 8)
 220                 return -EINVAL;
 221
 222         /* Build transaction */
 223         ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
 224                    (msg->addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
 225
 226         if ((msg->flags & I2C_M_TEN) != 0)
 227                 ctrl_reg |=  MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
 228
 229         if ((msg->flags & I2C_M_RD) == 0) {
 230                 u8 local_buf[8] = { 0 };
 231
 232                 memcpy(local_buf, msg->buf, msg->len);
 233                 data_reg_lo = cpu_to_le32(*((u32 *)local_buf));
 234                 data_reg_hi = cpu_to_le32(*((u32 *)(local_buf+4)));
 235
 236                 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
 237                     (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT;
 238
 239                 writel(data_reg_lo,
 240                         drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
 241                 writel(data_reg_hi,
 242                         drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
 243
 244         } else {
 245                 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
 246                     (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT;
 247         }
 248
 249         /* Execute transaction */
 250         writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
 251
 252         return 0;
 253 }
 254
 255 static void
 256 mv64xxx_i2c_update_offload_data(struct mv64xxx_i2c_data *drv_data)
 257 {
 258         struct i2c_msg *msg = drv_data->msg;
 259
 260         if (msg->flags & I2C_M_RD) {
 261                 u32 data_reg_lo = readl(drv_data->reg_base +
 262                                 MV64XXX_I2C_REG_RX_DATA_LO);
 263                 u32 data_reg_hi = readl(drv_data->reg_base +
 264                                 MV64XXX_I2C_REG_RX_DATA_HI);
 265                 u8 local_buf[8] = { 0 };
 266
 267                 *((u32 *)local_buf) = le32_to_cpu(data_reg_lo);
 268                 *((u32 *)(local_buf+4)) = le32_to_cpu(data_reg_hi);
 269                 memcpy(msg->buf, local_buf, msg->len);
 270         }
 271
 272 }
 273 /*
 274  *****************************************************************************
 275  *
 276  *      Finite State Machine & Interrupt Routines
 277  *
 278  *****************************************************************************
 279  */
 280
 281 /* Reset hardware and initialize FSM */
 282 static void
 283 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
 284 {
 285         if (drv_data->offload_enabled) {
 286                 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
 287                 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING);
 288                 writel(0, drv_data->reg_base +
 289                         MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
 290                 writel(0, drv_data->reg_base +
 291                         MV64XXX_I2C_REG_BRIDGE_INTR_MASK);
 292         }
 293
 294         writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset);
 295         writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n),
 296                 drv_data->reg_base + drv_data->reg_offsets.clock);
 297         writel(0, drv_data->reg_base + drv_data->reg_offsets.addr);
 298         writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr);
 299         writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
 300                 drv_data->reg_base + drv_data->reg_offsets.control);
 301         drv_data->state = MV64XXX_I2C_STATE_IDLE;
 302 }
 303
 304 static void
 305 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
 306 {
 307         /*
 308          * If state is idle, then this is likely the remnants of an old
 309          * operation that driver has given up on or the user has killed.
 310          * If so, issue the stop condition and go to idle.
 311          */
 312         if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
 313                 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
 314                 return;
 315         }
 316
 317         /* The status from the ctlr [mostly] tells us what to do next */
 318         switch (status) {
 319         /* Start condition interrupt */
 320         case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
 321         case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
 322                 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
 323                 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
 324                 break;
 325
 326         /* Performing a write */
 327         case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
 328                 if (drv_data->msg->flags & I2C_M_TEN) {
 329                         drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
 330                         drv_data->state =
 331                                 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
 332                         break;
 333                 }
 334                 /* FALLTHRU */
 335         case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
 336         case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
 337                 if ((drv_data->bytes_left == 0)
 338                                 || (drv_data->aborting
 339                                         && (drv_data->byte_posn != 0))) {
 340                         if (drv_data->send_stop || drv_data->aborting) {
 341                                 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
 342                                 drv_data->state = MV64XXX_I2C_STATE_IDLE;
 343                         } else {
 344                                 drv_data->action =
 345                                         MV64XXX_I2C_ACTION_SEND_RESTART;
 346                                 drv_data->state =
 347                                         MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
 348                         }
 349                 } else {
 350                         drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
 351                         drv_data->state =
 352                                 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
 353                         drv_data->bytes_left--;
 354                 }
 355                 break;
 356
 357         /* Performing a read */
 358         case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
 359                 if (drv_data->msg->flags & I2C_M_TEN) {
 360                         drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
 361                         drv_data->state =
 362                                 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
 363                         break;
 364                 }
 365                 /* FALLTHRU */
 366         case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
 367                 if (drv_data->bytes_left == 0) {
 368                         drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
 369                         drv_data->state = MV64XXX_I2C_STATE_IDLE;
 370                         break;
 371                 }
 372                 /* FALLTHRU */
 373         case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
 374                 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
 375                         drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
 376                 else {
 377                         drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
 378                         drv_data->bytes_left--;
 379                 }
 380                 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
 381
 382                 if ((drv_data->bytes_left == 1) || drv_data->aborting)
 383                         drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
 384                 break;
 385
 386         case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
 387                 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
 388                 drv_data->state = MV64XXX_I2C_STATE_IDLE;
 389                 break;
 390
 391         case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
 392         case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
 393         case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
 394                 /* Doesn't seem to be a device at other end */
 395                 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
 396                 drv_data->state = MV64XXX_I2C_STATE_IDLE;
 397                 drv_data->rc = -ENXIO;
 398                 break;
 399
 400         case MV64XXX_I2C_STATUS_OFFLOAD_OK:
 401                 if (drv_data->send_stop || drv_data->aborting) {
 402                         drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP;
 403                         drv_data->state = MV64XXX_I2C_STATE_IDLE;
 404                 } else {
 405                         drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_RESTART;
 406                         drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
 407                 }
 408                 break;
 409
 410         default:
 411                 dev_err(&drv_data->adapter.dev,
 412                         "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
 413                         "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
 414                          drv_data->state, status, drv_data->msg->addr,
 415                          drv_data->msg->flags);
 416                 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
 417                 mv64xxx_i2c_hw_init(drv_data);
 418                 drv_data->rc = -EIO;
 419         }
 420 }
 421
 422 static void
 423 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
 424 {
 425         switch(drv_data->action) {
 426         case MV64XXX_I2C_ACTION_OFFLOAD_RESTART:
 427                 mv64xxx_i2c_update_offload_data(drv_data);
 428                 writel(0, drv_data->reg_base +  MV64XXX_I2C_REG_BRIDGE_CONTROL);
 429                 writel(0, drv_data->reg_base +
 430                         MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
 431                 /* FALLTHRU */
 432         case MV64XXX_I2C_ACTION_SEND_RESTART:
 433                 /* We should only get here if we have further messages */
 434                 BUG_ON(drv_data->num_msgs == 0);
 435
 436                 drv_data->msgs++;
 437                 drv_data->num_msgs--;
 438                 if (mv64xxx_i2c_offload_msg(drv_data) < 0) {
 439                         drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_START;
 440                         writel(drv_data->cntl_bits,
 441                         drv_data->reg_base + drv_data->reg_offsets.control);
 442
 443                         /* Setup for the next message */
 444                         mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
 445                 }
 446                 if (drv_data->errata_delay)
 447                         udelay(5);
 448
 449                 /*
 450                  * We're never at the start of the message here, and by this
 451                  * time it's already too late to do any protocol mangling.
 452                  * Thankfully, do not advertise support for that feature.
 453                  */
 454                 drv_data->send_stop = drv_data->num_msgs == 1;
 455                 break;
 456
 457         case MV64XXX_I2C_ACTION_CONTINUE:
 458                 writel(drv_data->cntl_bits,
 459                         drv_data->reg_base + drv_data->reg_offsets.control);
 460                 break;
 461
 462         case MV64XXX_I2C_ACTION_SEND_START:
 463                 /* Can we offload this msg ? */
 464                 if (mv64xxx_i2c_offload_msg(drv_data) < 0) {
 465                         /* No, switch to standard path */
 466                         mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
 467                         writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
 468                                 drv_data->reg_base + drv_data->reg_offsets.control);
 469                 }
 470                 break;
 471
 472         case MV64XXX_I2C_ACTION_SEND_ADDR_1:
 473                 writel(drv_data->addr1,
 474                         drv_data->reg_base + drv_data->reg_offsets.data);
 475                 writel(drv_data->cntl_bits,
 476                         drv_data->reg_base + drv_data->reg_offsets.control);
 477                 break;
 478
 479         case MV64XXX_I2C_ACTION_SEND_ADDR_2:
 480                 writel(drv_data->addr2,
 481                         drv_data->reg_base + drv_data->reg_offsets.data);
 482                 writel(drv_data->cntl_bits,
 483                         drv_data->reg_base + drv_data->reg_offsets.control);
 484                 break;
 485
 486         case MV64XXX_I2C_ACTION_SEND_DATA:
 487                 writel(drv_data->msg->buf[drv_data->byte_posn++],
 488                         drv_data->reg_base + drv_data->reg_offsets.data);
 489                 writel(drv_data->cntl_bits,
 490                         drv_data->reg_base + drv_data->reg_offsets.control);
 491                 break;
 492
 493         case MV64XXX_I2C_ACTION_RCV_DATA:
 494                 drv_data->msg->buf[drv_data->byte_posn++] =
 495                         readl(drv_data->reg_base + drv_data->reg_offsets.data);
 496                 writel(drv_data->cntl_bits,
 497                         drv_data->reg_base + drv_data->reg_offsets.control);
 498                 break;
 499
 500         case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
 501                 drv_data->msg->buf[drv_data->byte_posn++] =
 502                         readl(drv_data->reg_base + drv_data->reg_offsets.data);
 503                 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
 504                 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
 505                         drv_data->reg_base + drv_data->reg_offsets.control);
 506                 drv_data->block = 0;
 507                 if (drv_data->errata_delay)
 508                         udelay(5);
 509
 510                 wake_up(&drv_data->waitq);
 511                 break;
 512
 513         case MV64XXX_I2C_ACTION_INVALID:
 514         default:
 515                 dev_err(&drv_data->adapter.dev,
 516                         "mv64xxx_i2c_do_action: Invalid action: %d\n",
 517                         drv_data->action);
 518                 drv_data->rc = -EIO;
 519
 520                 /* FALLTHRU */
 521         case MV64XXX_I2C_ACTION_SEND_STOP:
 522                 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
 523                 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
 524                         drv_data->reg_base + drv_data->reg_offsets.control);
 525                 drv_data->block = 0;
 526                 wake_up(&drv_data->waitq);
 527                 break;
 528
 529         case MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP:
 530                 mv64xxx_i2c_update_offload_data(drv_data);
 531                 writel(0, drv_data->reg_base +  MV64XXX_I2C_REG_BRIDGE_CONTROL);
 532                 writel(0, drv_data->reg_base +
 533                         MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
 534                 drv_data->block = 0;
 535                 wake_up(&drv_data->waitq);
 536                 break;
 537         }
 538 }
 539
 540 static irqreturn_t
 541 mv64xxx_i2c_intr(int irq, void *dev_id)
 542 {
 543         struct mv64xxx_i2c_data *drv_data = dev_id;
 544         unsigned long   flags;
 545         u32             status;
 546         irqreturn_t     rc = IRQ_NONE;
 547
 548         spin_lock_irqsave(&drv_data->lock, flags);
 549
 550         if (drv_data->offload_enabled) {
 551                 while (readl(drv_data->reg_base +
 552                                 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE)) {
 553                         int reg_status = readl(drv_data->reg_base +
 554                                         MV64XXX_I2C_REG_BRIDGE_STATUS);
 555                         if (reg_status & MV64XXX_I2C_BRIDGE_STATUS_ERROR)
 556                                 status = MV64XXX_I2C_STATUS_OFFLOAD_ERROR;
 557                         else
 558                                 status = MV64XXX_I2C_STATUS_OFFLOAD_OK;
 559                         mv64xxx_i2c_fsm(drv_data, status);
 560                         mv64xxx_i2c_do_action(drv_data);
 561                         rc = IRQ_HANDLED;
 562                 }
 563         }
 564         while (readl(drv_data->reg_base + drv_data->reg_offsets.control) &
 565                                                 MV64XXX_I2C_REG_CONTROL_IFLG) {
 566                 status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
 567                 mv64xxx_i2c_fsm(drv_data, status);
 568                 mv64xxx_i2c_do_action(drv_data);
 569                 rc = IRQ_HANDLED;
 570         }
 571         spin_unlock_irqrestore(&drv_data->lock, flags);
 572
 573         return rc;
 574 }
 575
 576 /*
 577  *****************************************************************************
 578  *
 579  *      I2C Msg Execution Routines
 580  *
 581  *****************************************************************************
 582  */
 583 static void
 584 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
 585 {
 586         long            time_left;
 587         unsigned long   flags;
 588         char            abort = 0;
 589
 590         time_left = wait_event_timeout(drv_data->waitq,
 591                 !drv_data->block, drv_data->adapter.timeout);
 592
 593         spin_lock_irqsave(&drv_data->lock, flags);
 594         if (!time_left) { /* Timed out */
 595                 drv_data->rc = -ETIMEDOUT;
 596                 abort = 1;
 597         } else if (time_left < 0) { /* Interrupted/Error */
 598                 drv_data->rc = time_left; /* errno value */
 599                 abort = 1;
 600         }
 601
 602         if (abort && drv_data->block) {
 603                 drv_data->aborting = 1;
 604                 spin_unlock_irqrestore(&drv_data->lock, flags);
 605
 606                 time_left = wait_event_timeout(drv_data->waitq,
 607                         !drv_data->block, drv_data->adapter.timeout);
 608
 609                 if ((time_left <= 0) && drv_data->block) {
 610                         drv_data->state = MV64XXX_I2C_STATE_IDLE;
 611                         dev_err(&drv_data->adapter.dev,
 612                                 "mv64xxx: I2C bus locked, block: %d, "
 613                                 "time_left: %d\n", drv_data->block,
 614                                 (int)time_left);
 615                         mv64xxx_i2c_hw_init(drv_data);
 616                 }
 617         } else
 618                 spin_unlock_irqrestore(&drv_data->lock, flags);
 619 }
 620
 621 static int
 622 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
 623                                 int is_last)
 624 {
 625         unsigned long   flags;
 626
 627         spin_lock_irqsave(&drv_data->lock, flags);
 628
 629         drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
 630         drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
 631
 632         drv_data->send_stop = is_last;
 633         drv_data->block = 1;
 634         mv64xxx_i2c_do_action(drv_data);
 635         spin_unlock_irqrestore(&drv_data->lock, flags);
 636
 637         mv64xxx_i2c_wait_for_completion(drv_data);
 638         return drv_data->rc;
 639 }
 640
 641 /*
 642  *****************************************************************************
 643  *
 644  *      I2C Core Support Routines (Interface to higher level I2C code)
 645  *
 646  *****************************************************************************
 647  */
 648 static u32
 649 mv64xxx_i2c_functionality(struct i2c_adapter *adap)
 650 {
 651         return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
 652 }
 653
 654 static int
 655 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 656 {
 657         struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
 658         int rc, ret = num;
 659
 660         BUG_ON(drv_data->msgs != NULL);
 661         drv_data->msgs = msgs;
 662         drv_data->num_msgs = num;
 663
 664         rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
 665         if (rc < 0)
 666                 ret = rc;
 667
 668         drv_data->num_msgs = 0;
 669         drv_data->msgs = NULL;
 670
 671         return ret;
 672 }
 673
 674 static const struct i2c_algorithm mv64xxx_i2c_algo = {
 675         .master_xfer = mv64xxx_i2c_xfer,
 676         .functionality = mv64xxx_i2c_functionality,
 677 };
 678
 679 /*
 680  *****************************************************************************
 681  *
 682  *      Driver Interface & Early Init Routines
 683  *
 684  *****************************************************************************
 685  */
 686 static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
 687         { .compatible = "allwinner,sun4i-i2c", .data = &mv64xxx_i2c_regs_sun4i},
 688         { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
 689         { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
 690         { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
 691         {}
 692 };
 693 MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
 694
 695 #ifdef CONFIG_OF
 696 #ifdef CONFIG_HAVE_CLK
 697 static int
 698 mv64xxx_calc_freq(const int tclk, const int n, const int m)
 699 {
 700         return tclk / (10 * (m + 1) * (2 << n));
 701 }
 702
 703 static bool
 704 mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n,
 705                           u32 *best_m)
 706 {
 707         int freq, delta, best_delta = INT_MAX;
 708         int m, n;
 709
 710         for (n = 0; n <= 7; n++)
 711                 for (m = 0; m <= 15; m++) {
 712                         freq = mv64xxx_calc_freq(tclk, n, m);
 713                         delta = req_freq - freq;
 714                         if (delta >= 0 && delta < best_delta) {
 715                                 *best_m = m;
 716                                 *best_n = n;
 717                                 best_delta = delta;
 718                         }
 719                         if (best_delta == 0)
 720                                 return true;
 721                 }
 722         if (best_delta == INT_MAX)
 723                 return false;
 724         return true;
 725 }
 726 #endif /* CONFIG_HAVE_CLK */
 727
 728 static int
 729 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 730                   struct device *dev)
 731 {
 732         /* CLK is mandatory when using DT to describe the i2c bus. We
 733          * need to know tclk in order to calculate bus clock
 734          * factors.
 735          */
 736 #if !defined(CONFIG_HAVE_CLK)
 737         /* Have OF but no CLK */
 738         return -ENODEV;
 739 #else
 740         const struct of_device_id *device;
 741         struct device_node *np = dev->of_node;
 742         u32 bus_freq, tclk;
 743         int rc = 0;
 744
 745         if (IS_ERR(drv_data->clk)) {
 746                 rc = -ENODEV;
 747                 goto out;
 748         }
 749         tclk = clk_get_rate(drv_data->clk);
 750
 751         rc = of_property_read_u32(np, "clock-frequency", &bus_freq);
 752         if (rc)
 753                 bus_freq = 100000; /* 100kHz by default */
 754
 755         if (!mv64xxx_find_baud_factors(bus_freq, tclk,
 756                                        &drv_data->freq_n, &drv_data->freq_m)) {
 757                 rc = -EINVAL;
 758                 goto out;
 759         }
 760         drv_data->irq = irq_of_parse_and_map(np, 0);
 761
 762         /* Its not yet defined how timeouts will be specified in device tree.
 763          * So hard code the value to 1 second.
 764          */
 765         drv_data->adapter.timeout = HZ;
 766
 767         device = of_match_device(mv64xxx_i2c_of_match_table, dev);
 768         if (!device)
 769                 return -ENODEV;
 770
 771         memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets));
 772
 773         /*
 774          * For controllers embedded in new SoCs activate the
 775          * Transaction Generator support and the errata fix.
 776          */
 777         if (of_device_is_compatible(np, "marvell,mv78230-i2c")) {
 778                 drv_data->offload_enabled = true;
 779                 drv_data->errata_delay = true;
 780         }
 781
 782         if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) {
 783                 drv_data->offload_enabled = false;
 784                 drv_data->errata_delay = true;
 785         }
 786 out:
 787         return rc;
 788 #endif
 789 }
 790 #else /* CONFIG_OF */
 791 static int
 792 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 793                   struct device *dev)
 794 {
 795         return -ENODEV;
 796 }
 797 #endif /* CONFIG_OF */
 798
 799 static int
 800 mv64xxx_i2c_probe(struct platform_device *pd)
 801 {
 802         struct mv64xxx_i2c_data         *drv_data;
 803         struct mv64xxx_i2c_pdata        *pdata = dev_get_platdata(&pd->dev);
 804         struct resource *r;
 805         int     rc;
 806
 807         if ((!pdata && !pd->dev.of_node))
 808                 return -ENODEV;
 809
 810         drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data),
 811                                 GFP_KERNEL);
 812         if (!drv_data)
 813                 return -ENOMEM;
 814
 815         r = platform_get_resource(pd, IORESOURCE_MEM, 0);
 816         drv_data->reg_base = devm_ioremap_resource(&pd->dev, r);
 817         if (IS_ERR(drv_data->reg_base))
 818                 return PTR_ERR(drv_data->reg_base);
 819
 820         strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
 821                 sizeof(drv_data->adapter.name));
 822
 823         init_waitqueue_head(&drv_data->waitq);
 824         spin_lock_init(&drv_data->lock);
 825
 826 #if defined(CONFIG_HAVE_CLK)
 827         /* Not all platforms have a clk */
 828         drv_data->clk = devm_clk_get(&pd->dev, NULL);
 829         if (!IS_ERR(drv_data->clk)) {
 830                 clk_prepare(drv_data->clk);
 831                 clk_enable(drv_data->clk);
 832         }
 833 #endif
 834         if (pdata) {
 835                 drv_data->freq_m = pdata->freq_m;
 836                 drv_data->freq_n = pdata->freq_n;
 837                 drv_data->irq = platform_get_irq(pd, 0);
 838                 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
 839                 drv_data->offload_enabled = false;
 840                 memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets));
 841         } else if (pd->dev.of_node) {
 842                 rc = mv64xxx_of_config(drv_data, &pd->dev);
 843                 if (rc)
 844                         goto exit_clk;
 845         }
 846         if (drv_data->irq < 0) {
 847                 rc = -ENXIO;
 848                 goto exit_clk;
 849         }
 850
 851         drv_data->adapter.dev.parent = &pd->dev;
 852         drv_data->adapter.algo = &mv64xxx_i2c_algo;
 853         drv_data->adapter.owner = THIS_MODULE;
 854         drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 855         drv_data->adapter.nr = pd->id;
 856         drv_data->adapter.dev.of_node = pd->dev.of_node;
 857         platform_set_drvdata(pd, drv_data);
 858         i2c_set_adapdata(&drv_data->adapter, drv_data);
 859
 860         mv64xxx_i2c_hw_init(drv_data);
 861
 862         rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
 863                          MV64XXX_I2C_CTLR_NAME, drv_data);
 864         if (rc) {
 865                 dev_err(&drv_data->adapter.dev,
 866                         "mv64xxx: Can't register intr handler irq%d: %d\n",
 867                         drv_data->irq, rc);
 868                 goto exit_clk;
 869         } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
 870                 dev_err(&drv_data->adapter.dev,
 871                         "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
 872                 goto exit_free_irq;
 873         }
 874
 875         return 0;
 876
 877 exit_free_irq:
 878         free_irq(drv_data->irq, drv_data);
 879 exit_clk:
 880 #if defined(CONFIG_HAVE_CLK)
 881         /* Not all platforms have a clk */
 882         if (!IS_ERR(drv_data->clk)) {
 883                 clk_disable(drv_data->clk);
 884                 clk_unprepare(drv_data->clk);
 885         }
 886 #endif
 887         return rc;
 888 }
 889
 890 static int
 891 mv64xxx_i2c_remove(struct platform_device *dev)
 892 {
 893         struct mv64xxx_i2c_data         *drv_data = platform_get_drvdata(dev);
 894
 895         i2c_del_adapter(&drv_data->adapter);
 896         free_irq(drv_data->irq, drv_data);
 897 #if defined(CONFIG_HAVE_CLK)
 898         /* Not all platforms have a clk */
 899         if (!IS_ERR(drv_data->clk)) {
 900                 clk_disable(drv_data->clk);
 901                 clk_unprepare(drv_data->clk);
 902         }
 903 #endif
 904
 905         return 0;
 906 }
 907
 908 static struct platform_driver mv64xxx_i2c_driver = {
 909         .probe  = mv64xxx_i2c_probe,
 910         .remove = mv64xxx_i2c_remove,
 911         .driver = {
 912                 .owner  = THIS_MODULE,
 913                 .name   = MV64XXX_I2C_CTLR_NAME,
 914                 .of_match_table = mv64xxx_i2c_of_match_table,
 915         },
 916 };
 917
 918 module_platform_driver(mv64xxx_i2c_driver);
 919
 920 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
 921 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
 922 MODULE_LICENSE("GPL");