drivers/i2c/busses/i2c-bcm-iproc.c

   1 /*
   2  * Copyright (C) 2014 Broadcom Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation version 2.
   7  *
   8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
   9  * kind, whether express or implied; without even the implied warranty
  10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/delay.h>
  15 #include <linux/i2c.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/io.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/of_device.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23
  24 #define IDM_CTRL_DIRECT_OFFSET       0x00
  25 #define CFG_OFFSET                   0x00
  26 #define CFG_RESET_SHIFT              31
  27 #define CFG_EN_SHIFT                 30
  28 #define CFG_SLAVE_ADDR_0_SHIFT       28
  29 #define CFG_M_RETRY_CNT_SHIFT        16
  30 #define CFG_M_RETRY_CNT_MASK         0x0f
  31
  32 #define TIM_CFG_OFFSET               0x04
  33 #define TIM_CFG_MODE_400_SHIFT       31
  34 #define TIM_RAND_SLAVE_STRETCH_SHIFT      24
  35 #define TIM_RAND_SLAVE_STRETCH_MASK       0x7f
  36 #define TIM_PERIODIC_SLAVE_STRETCH_SHIFT  16
  37 #define TIM_PERIODIC_SLAVE_STRETCH_MASK   0x7f
  38
  39 #define S_CFG_SMBUS_ADDR_OFFSET           0x08
  40 #define S_CFG_EN_NIC_SMB_ADDR3_SHIFT      31
  41 #define S_CFG_NIC_SMB_ADDR3_SHIFT         24
  42 #define S_CFG_NIC_SMB_ADDR3_MASK          0x7f
  43 #define S_CFG_EN_NIC_SMB_ADDR2_SHIFT      23
  44 #define S_CFG_NIC_SMB_ADDR2_SHIFT         16
  45 #define S_CFG_NIC_SMB_ADDR2_MASK          0x7f
  46 #define S_CFG_EN_NIC_SMB_ADDR1_SHIFT      15
  47 #define S_CFG_NIC_SMB_ADDR1_SHIFT         8
  48 #define S_CFG_NIC_SMB_ADDR1_MASK          0x7f
  49 #define S_CFG_EN_NIC_SMB_ADDR0_SHIFT      7
  50 #define S_CFG_NIC_SMB_ADDR0_SHIFT         0
  51 #define S_CFG_NIC_SMB_ADDR0_MASK          0x7f
  52
  53 #define M_FIFO_CTRL_OFFSET           0x0c
  54 #define M_FIFO_RX_FLUSH_SHIFT        31
  55 #define M_FIFO_TX_FLUSH_SHIFT        30
  56 #define M_FIFO_RX_CNT_SHIFT          16
  57 #define M_FIFO_RX_CNT_MASK           0x7f
  58 #define M_FIFO_RX_THLD_SHIFT         8
  59 #define M_FIFO_RX_THLD_MASK          0x3f
  60
  61 #define S_FIFO_CTRL_OFFSET           0x10
  62 #define S_FIFO_RX_FLUSH_SHIFT        31
  63 #define S_FIFO_TX_FLUSH_SHIFT        30
  64 #define S_FIFO_RX_CNT_SHIFT          16
  65 #define S_FIFO_RX_CNT_MASK           0x7f
  66 #define S_FIFO_RX_THLD_SHIFT         8
  67 #define S_FIFO_RX_THLD_MASK          0x3f
  68
  69 #define M_CMD_OFFSET                 0x30
  70 #define M_CMD_START_BUSY_SHIFT       31
  71 #define M_CMD_STATUS_SHIFT           25
  72 #define M_CMD_STATUS_MASK            0x07
  73 #define M_CMD_STATUS_SUCCESS         0x0
  74 #define M_CMD_STATUS_LOST_ARB        0x1
  75 #define M_CMD_STATUS_NACK_ADDR       0x2
  76 #define M_CMD_STATUS_NACK_DATA       0x3
  77 #define M_CMD_STATUS_TIMEOUT         0x4
  78 #define M_CMD_STATUS_FIFO_UNDERRUN   0x5
  79 #define M_CMD_STATUS_RX_FIFO_FULL    0x6
  80 #define M_CMD_PROTOCOL_SHIFT         9
  81 #define M_CMD_PROTOCOL_MASK          0xf
  82 #define M_CMD_PROTOCOL_QUICK         0x0
  83 #define M_CMD_PROTOCOL_BLK_WR        0x7
  84 #define M_CMD_PROTOCOL_BLK_RD        0x8
  85 #define M_CMD_PROTOCOL_PROCESS       0xa
  86 #define M_CMD_PEC_SHIFT              8
  87 #define M_CMD_RD_CNT_SHIFT           0
  88 #define M_CMD_RD_CNT_MASK            0xff
  89
  90 #define S_CMD_OFFSET                 0x34
  91 #define S_CMD_START_BUSY_SHIFT       31
  92 #define S_CMD_STATUS_SHIFT           23
  93 #define S_CMD_STATUS_MASK            0x07
  94 #define S_CMD_STATUS_SUCCESS         0x0
  95 #define S_CMD_STATUS_TIMEOUT         0x5
  96 #define S_CMD_STATUS_MASTER_ABORT    0x7
  97
  98 #define IE_OFFSET                    0x38
  99 #define IE_M_RX_FIFO_FULL_SHIFT      31
 100 #define IE_M_RX_THLD_SHIFT           30
 101 #define IE_M_START_BUSY_SHIFT        28
 102 #define IE_M_TX_UNDERRUN_SHIFT       27
 103 #define IE_S_RX_FIFO_FULL_SHIFT      26
 104 #define IE_S_RX_THLD_SHIFT           25
 105 #define IE_S_RX_EVENT_SHIFT          24
 106 #define IE_S_START_BUSY_SHIFT        23
 107 #define IE_S_TX_UNDERRUN_SHIFT       22
 108 #define IE_S_RD_EVENT_SHIFT          21
 109
 110 #define IS_OFFSET                    0x3c
 111 #define IS_M_RX_FIFO_FULL_SHIFT      31
 112 #define IS_M_RX_THLD_SHIFT           30
 113 #define IS_M_START_BUSY_SHIFT        28
 114 #define IS_M_TX_UNDERRUN_SHIFT       27
 115 #define IS_S_RX_FIFO_FULL_SHIFT      26
 116 #define IS_S_RX_THLD_SHIFT           25
 117 #define IS_S_RX_EVENT_SHIFT          24
 118 #define IS_S_START_BUSY_SHIFT        23
 119 #define IS_S_TX_UNDERRUN_SHIFT       22
 120 #define IS_S_RD_EVENT_SHIFT          21
 121
 122 #define M_TX_OFFSET                  0x40
 123 #define M_TX_WR_STATUS_SHIFT         31
 124 #define M_TX_DATA_SHIFT              0
 125 #define M_TX_DATA_MASK               0xff
 126
 127 #define M_RX_OFFSET                  0x44
 128 #define M_RX_STATUS_SHIFT            30
 129 #define M_RX_STATUS_MASK             0x03
 130 #define M_RX_PEC_ERR_SHIFT           29
 131 #define M_RX_DATA_SHIFT              0
 132 #define M_RX_DATA_MASK               0xff
 133
 134 #define S_TX_OFFSET                  0x48
 135 #define S_TX_WR_STATUS_SHIFT         31
 136 #define S_TX_DATA_SHIFT              0
 137 #define S_TX_DATA_MASK               0xff
 138
 139 #define S_RX_OFFSET                  0x4c
 140 #define S_RX_STATUS_SHIFT            30
 141 #define S_RX_STATUS_MASK             0x03
 142 #define S_RX_PEC_ERR_SHIFT           29
 143 #define S_RX_DATA_SHIFT              0
 144 #define S_RX_DATA_MASK               0xff
 145
 146 #define I2C_TIMEOUT_MSEC             50000
 147 #define M_TX_RX_FIFO_SIZE            64
 148 #define M_RX_FIFO_MAX_THLD_VALUE     (M_TX_RX_FIFO_SIZE - 1)
 149
 150 #define M_RX_MAX_READ_LEN            255
 151 #define M_RX_FIFO_THLD_VALUE         50
 152
 153 #define IE_M_ALL_INTERRUPT_SHIFT     27
 154 #define IE_M_ALL_INTERRUPT_MASK      0x1e
 155
 156 #define SLAVE_READ_WRITE_BIT_MASK    0x1
 157 #define SLAVE_READ_WRITE_BIT_SHIFT   0x1
 158 #define SLAVE_MAX_SIZE_TRANSACTION   64
 159 #define SLAVE_CLOCK_STRETCH_TIME     25
 160
 161 #define IE_S_ALL_INTERRUPT_SHIFT     21
 162 #define IE_S_ALL_INTERRUPT_MASK      0x3f
 163 /*
 164  * It takes ~18us to reading 10bytes of data, hence to keep tasklet
 165  * running for less time, max slave read per tasklet is set to 10 bytes.
 166  */
 167 #define MAX_SLAVE_RX_PER_INT         10
 168
 169 enum i2c_slave_read_status {
 170         I2C_SLAVE_RX_FIFO_EMPTY = 0,
 171         I2C_SLAVE_RX_START,
 172         I2C_SLAVE_RX_DATA,
 173         I2C_SLAVE_RX_END,
 174 };
 175
 176 enum bus_speed_index {
 177         I2C_SPD_100K = 0,
 178         I2C_SPD_400K,
 179 };
 180
 181 enum bcm_iproc_i2c_type {
 182         IPROC_I2C,
 183         IPROC_I2C_NIC
 184 };
 185
 186 struct bcm_iproc_i2c_dev {
 187         struct device *device;
 188         enum bcm_iproc_i2c_type type;
 189         int irq;
 190
 191         void __iomem *base;
 192         void __iomem *idm_base;
 193
 194         u32 ape_addr_mask;
 195
 196         /* lock for indirect access through IDM */
 197         spinlock_t idm_lock;
 198
 199         struct i2c_adapter adapter;
 200         unsigned int bus_speed;
 201
 202         struct completion done;
 203         int xfer_is_done;
 204
 205         struct i2c_msg *msg;
 206
 207         struct i2c_client *slave;
 208
 209         /* bytes that have been transferred */
 210         unsigned int tx_bytes;
 211         /* bytes that have been read */
 212         unsigned int rx_bytes;
 213         unsigned int thld_bytes;
 214
 215         bool slave_rx_only;
 216         bool rx_start_rcvd;
 217         bool slave_read_complete;
 218         u32 tx_underrun;
 219         u32 slave_int_mask;
 220         struct tasklet_struct slave_rx_tasklet;
 221 };
 222
 223 /* tasklet to process slave rx data */
 224 static void slave_rx_tasklet_fn(unsigned long);
 225
 226 /*
 227  * Can be expanded in the future if more interrupt status bits are utilized
 228  */
 229 #define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\
 230                 | BIT(IS_M_RX_THLD_SHIFT))
 231
 232 #define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\
 233                 | BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\
 234                 | BIT(IS_S_TX_UNDERRUN_SHIFT) | BIT(IS_S_RX_FIFO_FULL_SHIFT)\
 235                 | BIT(IS_S_RX_THLD_SHIFT))
 236
 237 static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
 238 static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
 239 static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
 240                                          bool enable);
 241
 242 static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 243                                    u32 offset)
 244 {
 245         u32 val;
 246
 247         if (iproc_i2c->idm_base) {
 248                 spin_lock(&iproc_i2c->idm_lock);
 249                 writel(iproc_i2c->ape_addr_mask,
 250                        iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
 251                 val = readl(iproc_i2c->base + offset);
 252                 spin_unlock(&iproc_i2c->idm_lock);
 253         } else {
 254                 val = readl(iproc_i2c->base + offset);
 255         }
 256
 257         return val;
 258 }
 259
 260 static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 261                                     u32 offset, u32 val)
 262 {
 263         if (iproc_i2c->idm_base) {
 264                 spin_lock(&iproc_i2c->idm_lock);
 265                 writel(iproc_i2c->ape_addr_mask,
 266                        iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
 267                 writel(val, iproc_i2c->base + offset);
 268                 spin_unlock(&iproc_i2c->idm_lock);
 269         } else {
 270                 writel(val, iproc_i2c->base + offset);
 271         }
 272 }
 273
 274 static void bcm_iproc_i2c_slave_init(
 275         struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset)
 276 {
 277         u32 val;
 278
 279         iproc_i2c->tx_underrun = 0;
 280         if (need_reset) {
 281                 /* put controller in reset */
 282                 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
 283                 val |= BIT(CFG_RESET_SHIFT);
 284                 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 285
 286                 /* wait 100 usec per spec */
 287                 udelay(100);
 288
 289                 /* bring controller out of reset */
 290                 val &= ~(BIT(CFG_RESET_SHIFT));
 291                 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 292         }
 293
 294         /* flush TX/RX FIFOs */
 295         val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
 296         iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
 297
 298         /* Maximum slave stretch time */
 299         val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
 300         val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT);
 301         val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT);
 302         iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
 303
 304         /* Configure the slave address */
 305         val = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
 306         val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
 307         val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT);
 308         val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT);
 309         iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, val);
 310
 311         /* clear all pending slave interrupts */
 312         iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
 313
 314         /* Enable interrupt register to indicate a valid byte in receive fifo */
 315         val = BIT(IE_S_RX_EVENT_SHIFT);
 316         /* Enable interrupt register to indicate Slave Rx FIFO Full */
 317         val |= BIT(IE_S_RX_FIFO_FULL_SHIFT);
 318         /* Enable interrupt register to indicate a Master read transaction */
 319         val |= BIT(IE_S_RD_EVENT_SHIFT);
 320         /* Enable interrupt register for the Slave BUSY command */
 321         val |= BIT(IE_S_START_BUSY_SHIFT);
 322         iproc_i2c->slave_int_mask = val;
 323         iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
 324 }
 325
 326 static void bcm_iproc_i2c_check_slave_status(
 327         struct bcm_iproc_i2c_dev *iproc_i2c)
 328 {
 329         u32 val;
 330
 331         val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
 332         /* status is valid only when START_BUSY is cleared after it was set */
 333         if (val & BIT(S_CMD_START_BUSY_SHIFT))
 334                 return;
 335
 336         val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
 337         if (val == S_CMD_STATUS_TIMEOUT || val == S_CMD_STATUS_MASTER_ABORT) {
 338                 dev_err(iproc_i2c->device, (val == S_CMD_STATUS_TIMEOUT) ?
 339                         "slave random stretch time timeout\n" :
 340                         "Master aborted read transaction\n");
 341                 /* re-initialize i2c for recovery */
 342                 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
 343                 bcm_iproc_i2c_slave_init(iproc_i2c, true);
 344                 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
 345         }
 346 }
 347
 348 static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c)
 349 {
 350         u8 rx_data, rx_status;
 351         u32 rx_bytes = 0;
 352         u32 val;
 353
 354         while (rx_bytes < MAX_SLAVE_RX_PER_INT) {
 355                 val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
 356                 rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
 357                 rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
 358
 359                 if (rx_status == I2C_SLAVE_RX_START) {
 360                         /* Start of SMBUS Master write */
 361                         i2c_slave_event(iproc_i2c->slave,
 362                                         I2C_SLAVE_WRITE_REQUESTED, &rx_data);
 363                         iproc_i2c->rx_start_rcvd = true;
 364                         iproc_i2c->slave_read_complete = false;
 365                 } else if (rx_status == I2C_SLAVE_RX_DATA &&
 366                            iproc_i2c->rx_start_rcvd) {
 367                         /* Middle of SMBUS Master write */
 368                         i2c_slave_event(iproc_i2c->slave,
 369                                         I2C_SLAVE_WRITE_RECEIVED, &rx_data);
 370                 } else if (rx_status == I2C_SLAVE_RX_END &&
 371                            iproc_i2c->rx_start_rcvd) {
 372                         /* End of SMBUS Master write */
 373                         if (iproc_i2c->slave_rx_only)
 374                                 i2c_slave_event(iproc_i2c->slave,
 375                                                 I2C_SLAVE_WRITE_RECEIVED,
 376                                                 &rx_data);
 377
 378                         i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP,
 379                                         &rx_data);
 380                 } else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) {
 381                         iproc_i2c->rx_start_rcvd = false;
 382                         iproc_i2c->slave_read_complete = true;
 383                         break;
 384                 }
 385
 386                 rx_bytes++;
 387         }
 388 }
 389
 390 static void slave_rx_tasklet_fn(unsigned long data)
 391 {
 392         struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data;
 393         u32 int_clr;
 394
 395         bcm_iproc_i2c_slave_read(iproc_i2c);
 396
 397         /* clear pending IS_S_RX_EVENT_SHIFT interrupt */
 398         int_clr = BIT(IS_S_RX_EVENT_SHIFT);
 399
 400         if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) {
 401                 /*
 402                  * In case of single byte master-read request,
 403                  * IS_S_TX_UNDERRUN_SHIFT event is generated before
 404                  * IS_S_START_BUSY_SHIFT event. Hence start slave data send
 405                  * from first IS_S_TX_UNDERRUN_SHIFT event.
 406                  *
 407                  * This means don't send any data from slave when
 408                  * IS_S_RD_EVENT_SHIFT event is generated else it will increment
 409                  * eeprom or other backend slave driver read pointer twice.
 410                  */
 411                 iproc_i2c->tx_underrun = 0;
 412                 iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT);
 413
 414                 /* clear IS_S_RD_EVENT_SHIFT interrupt */
 415                 int_clr |= BIT(IS_S_RD_EVENT_SHIFT);
 416         }
 417
 418         /* clear slave interrupt */
 419         iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr);
 420         /* enable slave interrupts */
 421         iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask);
 422 }
 423
 424 static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
 425                                     u32 status)
 426 {
 427         u32 val;
 428         u8 value;
 429
 430         /*
 431          * Slave events in case of master-write, master-write-read and,
 432          * master-read
 433          *
 434          * Master-write     : only IS_S_RX_EVENT_SHIFT event
 435          * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
 436          *                    events
 437          * Master-read      : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
 438          *                    events or only IS_S_RD_EVENT_SHIFT
 439          *
 440          * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt
 441          * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes
 442          * full. This can happen if Master issues write requests of more than
 443          * 64 bytes.
 444          */
 445         if (status & BIT(IS_S_RX_EVENT_SHIFT) ||
 446             status & BIT(IS_S_RD_EVENT_SHIFT) ||
 447             status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) {
 448                 /* disable slave interrupts */
 449                 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
 450                 val &= ~iproc_i2c->slave_int_mask;
 451                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
 452
 453                 if (status & BIT(IS_S_RD_EVENT_SHIFT))
 454                         /* Master-write-read request */
 455                         iproc_i2c->slave_rx_only = false;
 456                 else
 457                         /* Master-write request only */
 458                         iproc_i2c->slave_rx_only = true;
 459
 460                 /* schedule tasklet to read data later */
 461                 tasklet_schedule(&iproc_i2c->slave_rx_tasklet);
 462
 463                 /*
 464                  * clear only IS_S_RX_EVENT_SHIFT and
 465                  * IS_S_RX_FIFO_FULL_SHIFT interrupt.
 466                  */
 467                 val = BIT(IS_S_RX_EVENT_SHIFT);
 468                 if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT))
 469                         val |= BIT(IS_S_RX_FIFO_FULL_SHIFT);
 470                 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val);
 471         }
 472
 473         if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
 474                 iproc_i2c->tx_underrun++;
 475                 if (iproc_i2c->tx_underrun == 1)
 476                         /* Start of SMBUS for Master Read */
 477                         i2c_slave_event(iproc_i2c->slave,
 478                                         I2C_SLAVE_READ_REQUESTED,
 479                                         &value);
 480                 else
 481                         /* Master read other than start */
 482                         i2c_slave_event(iproc_i2c->slave,
 483                                         I2C_SLAVE_READ_PROCESSED,
 484                                         &value);
 485
 486                 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
 487                 /* start transfer */
 488                 val = BIT(S_CMD_START_BUSY_SHIFT);
 489                 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
 490
 491                 /* clear interrupt */
 492                 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
 493                                  BIT(IS_S_TX_UNDERRUN_SHIFT));
 494         }
 495
 496         /* Stop received from master in case of master read transaction */
 497         if (status & BIT(IS_S_START_BUSY_SHIFT)) {
 498                 /*
 499                  * Disable interrupt for TX FIFO becomes empty and
 500                  * less than PKT_LENGTH bytes were output on the SMBUS
 501                  */
 502                 iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
 503                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
 504                                  iproc_i2c->slave_int_mask);
 505
 506                 /* End of SMBUS for Master Read */
 507                 val = BIT(S_TX_WR_STATUS_SHIFT);
 508                 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val);
 509
 510                 val = BIT(S_CMD_START_BUSY_SHIFT);
 511                 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
 512
 513                 /* flush TX FIFOs */
 514                 val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET);
 515                 val |= (BIT(S_FIFO_TX_FLUSH_SHIFT));
 516                 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
 517
 518                 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
 519
 520                 /* clear interrupt */
 521                 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
 522                                  BIT(IS_S_START_BUSY_SHIFT));
 523         }
 524
 525         /* check slave transmit status only if slave is transmitting */
 526         if (!iproc_i2c->slave_rx_only)
 527                 bcm_iproc_i2c_check_slave_status(iproc_i2c);
 528
 529         return true;
 530 }
 531
 532 static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
 533 {
 534         struct i2c_msg *msg = iproc_i2c->msg;
 535         uint32_t val;
 536
 537         /* Read valid data from RX FIFO */
 538         while (iproc_i2c->rx_bytes < msg->len) {
 539                 val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET);
 540
 541                 /* rx fifo empty */
 542                 if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK))
 543                         break;
 544
 545                 msg->buf[iproc_i2c->rx_bytes] =
 546                         (val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
 547                 iproc_i2c->rx_bytes++;
 548         }
 549 }
 550
 551 static void bcm_iproc_i2c_send(struct bcm_iproc_i2c_dev *iproc_i2c)
 552 {
 553         struct i2c_msg *msg = iproc_i2c->msg;
 554         unsigned int tx_bytes = msg->len - iproc_i2c->tx_bytes;
 555         unsigned int i;
 556         u32 val;
 557
 558         /* can only fill up to the FIFO size */
 559         tx_bytes = min_t(unsigned int, tx_bytes, M_TX_RX_FIFO_SIZE);
 560         for (i = 0; i < tx_bytes; i++) {
 561                 /* start from where we left over */
 562                 unsigned int idx = iproc_i2c->tx_bytes + i;
 563
 564                 val = msg->buf[idx];
 565
 566                 /* mark the last byte */
 567                 if (idx == msg->len - 1) {
 568                         val |= BIT(M_TX_WR_STATUS_SHIFT);
 569
 570                         if (iproc_i2c->irq) {
 571                                 u32 tmp;
 572
 573                                 /*
 574                                  * Since this is the last byte, we should now
 575                                  * disable TX FIFO underrun interrupt
 576                                  */
 577                                 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
 578                                 tmp &= ~BIT(IE_M_TX_UNDERRUN_SHIFT);
 579                                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
 580                                                  tmp);
 581                         }
 582                 }
 583
 584                 /* load data into TX FIFO */
 585                 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
 586         }
 587
 588         /* update number of transferred bytes */
 589         iproc_i2c->tx_bytes += tx_bytes;
 590 }
 591
 592 static void bcm_iproc_i2c_read(struct bcm_iproc_i2c_dev *iproc_i2c)
 593 {
 594         struct i2c_msg *msg = iproc_i2c->msg;
 595         u32 bytes_left, val;
 596
 597         bcm_iproc_i2c_read_valid_bytes(iproc_i2c);
 598         bytes_left = msg->len - iproc_i2c->rx_bytes;
 599         if (bytes_left == 0) {
 600                 if (iproc_i2c->irq) {
 601                         /* finished reading all data, disable rx thld event */
 602                         val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
 603                         val &= ~BIT(IS_M_RX_THLD_SHIFT);
 604                         iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
 605                 }
 606         } else if (bytes_left < iproc_i2c->thld_bytes) {
 607                 /* set bytes left as threshold */
 608                 val = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
 609                 val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
 610                 val |= (bytes_left << M_FIFO_RX_THLD_SHIFT);
 611                 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
 612                 iproc_i2c->thld_bytes = bytes_left;
 613         }
 614         /*
 615          * bytes_left >= iproc_i2c->thld_bytes,
 616          * hence no need to change the THRESHOLD SET.
 617          * It will remain as iproc_i2c->thld_bytes itself
 618          */
 619 }
 620
 621 static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
 622                                           u32 status)
 623 {
 624         /* TX FIFO is empty and we have more data to send */
 625         if (status & BIT(IS_M_TX_UNDERRUN_SHIFT))
 626                 bcm_iproc_i2c_send(iproc_i2c);
 627
 628         /* RX FIFO threshold is reached and data needs to be read out */
 629         if (status & BIT(IS_M_RX_THLD_SHIFT))
 630                 bcm_iproc_i2c_read(iproc_i2c);
 631
 632         /* transfer is done */
 633         if (status & BIT(IS_M_START_BUSY_SHIFT)) {
 634                 iproc_i2c->xfer_is_done = 1;
 635                 if (iproc_i2c->irq)
 636                         complete(&iproc_i2c->done);
 637         }
 638 }
 639
 640 static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
 641 {
 642         struct bcm_iproc_i2c_dev *iproc_i2c = data;
 643         u32 slave_status;
 644         u32 status;
 645         bool ret;
 646
 647         status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
 648         /* process only slave interrupt which are enabled */
 649         slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) &
 650                        ISR_MASK_SLAVE;
 651
 652         if (slave_status) {
 653                 ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status);
 654                 if (ret)
 655                         return IRQ_HANDLED;
 656                 else
 657                         return IRQ_NONE;
 658         }
 659
 660         status &= ISR_MASK;
 661         if (!status)
 662                 return IRQ_NONE;
 663
 664         /* process all master based events */
 665         bcm_iproc_i2c_process_m_event(iproc_i2c, status);
 666         iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
 667
 668         return IRQ_HANDLED;
 669 }
 670
 671 static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
 672 {
 673         u32 val;
 674
 675         /* put controller in reset */
 676         val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
 677         val |= BIT(CFG_RESET_SHIFT);
 678         val &= ~(BIT(CFG_EN_SHIFT));
 679         iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 680
 681         /* wait 100 usec per spec */
 682         udelay(100);
 683
 684         /* bring controller out of reset */
 685         val &= ~(BIT(CFG_RESET_SHIFT));
 686         iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 687
 688         /* flush TX/RX FIFOs and set RX FIFO threshold to zero */
 689         val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT));
 690         iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
 691         /* disable all interrupts */
 692         val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
 693         val &= ~(IE_M_ALL_INTERRUPT_MASK <<
 694                         IE_M_ALL_INTERRUPT_SHIFT);
 695         iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
 696
 697         /* clear all pending interrupts */
 698         iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff);
 699
 700         return 0;
 701 }
 702
 703 static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
 704                                          bool enable)
 705 {
 706         u32 val;
 707
 708         val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
 709         if (enable)
 710                 val |= BIT(CFG_EN_SHIFT);
 711         else
 712                 val &= ~BIT(CFG_EN_SHIFT);
 713         iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 714 }
 715
 716 static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
 717                                       struct i2c_msg *msg)
 718 {
 719         u32 val;
 720
 721         val = iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET);
 722         val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK;
 723
 724         switch (val) {
 725         case M_CMD_STATUS_SUCCESS:
 726                 return 0;
 727
 728         case M_CMD_STATUS_LOST_ARB:
 729                 dev_dbg(iproc_i2c->device, "lost bus arbitration\n");
 730                 return -EAGAIN;
 731
 732         case M_CMD_STATUS_NACK_ADDR:
 733                 dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
 734                 return -ENXIO;
 735
 736         case M_CMD_STATUS_NACK_DATA:
 737                 dev_dbg(iproc_i2c->device, "NAK data\n");
 738                 return -ENXIO;
 739
 740         case M_CMD_STATUS_TIMEOUT:
 741                 dev_dbg(iproc_i2c->device, "bus timeout\n");
 742                 return -ETIMEDOUT;
 743
 744         case M_CMD_STATUS_FIFO_UNDERRUN:
 745                 dev_dbg(iproc_i2c->device, "FIFO under-run\n");
 746                 return -ENXIO;
 747
 748         case M_CMD_STATUS_RX_FIFO_FULL:
 749                 dev_dbg(iproc_i2c->device, "RX FIFO full\n");
 750                 return -ETIMEDOUT;
 751
 752         default:
 753                 dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
 754
 755                 /* re-initialize i2c for recovery */
 756                 bcm_iproc_i2c_enable_disable(iproc_i2c, false);
 757                 bcm_iproc_i2c_init(iproc_i2c);
 758                 bcm_iproc_i2c_enable_disable(iproc_i2c, true);
 759
 760                 return -EIO;
 761         }
 762 }
 763
 764 static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
 765                                    struct i2c_msg *msg,
 766                                    u32 cmd)
 767 {
 768         unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MSEC);
 769         u32 val, status;
 770         int ret;
 771
 772         iproc_i2c_wr_reg(iproc_i2c, M_CMD_OFFSET, cmd);
 773
 774         if (iproc_i2c->irq) {
 775                 time_left = wait_for_completion_timeout(&iproc_i2c->done,
 776                                                         time_left);
 777                 /* disable all interrupts */
 778                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
 779                 /* read it back to flush the write */
 780                 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
 781                 /* make sure the interrupt handler isn't running */
 782                 synchronize_irq(iproc_i2c->irq);
 783
 784         } else { /* polling mode */
 785                 unsigned long timeout = jiffies + time_left;
 786
 787                 do {
 788                         status = iproc_i2c_rd_reg(iproc_i2c,
 789                                                   IS_OFFSET) & ISR_MASK;
 790                         bcm_iproc_i2c_process_m_event(iproc_i2c, status);
 791                         iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
 792
 793                         if (time_after(jiffies, timeout)) {
 794                                 time_left = 0;
 795                                 break;
 796                         }
 797
 798                         cpu_relax();
 799                         cond_resched();
 800                 } while (!iproc_i2c->xfer_is_done);
 801         }
 802
 803         if (!time_left && !iproc_i2c->xfer_is_done) {
 804                 dev_err(iproc_i2c->device, "transaction timed out\n");
 805
 806                 /* flush both TX/RX FIFOs */
 807                 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
 808                 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
 809                 return -ETIMEDOUT;
 810         }
 811
 812         ret = bcm_iproc_i2c_check_status(iproc_i2c, msg);
 813         if (ret) {
 814                 /* flush both TX/RX FIFOs */
 815                 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
 816                 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
 817                 return ret;
 818         }
 819
 820         return 0;
 821 }
 822
 823 /*
 824  * If 'process_call' is true, then this is a multi-msg transfer that requires
 825  * a repeated start between the messages.
 826  * More specifically, it must be a write (reg) followed by a read (data).
 827  * The i2c quirks are set to enforce this rule.
 828  */
 829 static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
 830                                         struct i2c_msg *msgs, bool process_call)
 831 {
 832         int i;
 833         u8 addr;
 834         u32 val, tmp, val_intr_en;
 835         unsigned int tx_bytes;
 836         struct i2c_msg *msg = &msgs[0];
 837
 838         /* check if bus is busy */
 839         if (!!(iproc_i2c_rd_reg(iproc_i2c,
 840                                 M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) {
 841                 dev_warn(iproc_i2c->device, "bus is busy\n");
 842                 return -EBUSY;
 843         }
 844
 845         iproc_i2c->msg = msg;
 846
 847         /* format and load slave address into the TX FIFO */
 848         addr = i2c_8bit_addr_from_msg(msg);
 849         iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, addr);
 850
 851         /*
 852          * For a write transaction, load data into the TX FIFO. Only allow
 853          * loading up to TX FIFO size - 1 bytes of data since the first byte
 854          * has been used up by the slave address
 855          */
 856         tx_bytes = min_t(unsigned int, msg->len, M_TX_RX_FIFO_SIZE - 1);
 857         if (!(msg->flags & I2C_M_RD)) {
 858                 for (i = 0; i < tx_bytes; i++) {
 859                         val = msg->buf[i];
 860
 861                         /* mark the last byte */
 862                         if (!process_call && (i == msg->len - 1))
 863                                 val |= BIT(M_TX_WR_STATUS_SHIFT);
 864
 865                         iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
 866                 }
 867                 iproc_i2c->tx_bytes = tx_bytes;
 868         }
 869
 870         /* Process the read message if this is process call */
 871         if (process_call) {
 872                 msg++;
 873                 iproc_i2c->msg = msg;  /* point to second msg */
 874
 875                 /*
 876                  * The last byte to be sent out should be a slave
 877                  * address with read operation
 878                  */
 879                 addr = i2c_8bit_addr_from_msg(msg);
 880                 /* mark it the last byte out */
 881                 val = addr | BIT(M_TX_WR_STATUS_SHIFT);
 882                 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
 883         }
 884
 885         /* mark as incomplete before starting the transaction */
 886         if (iproc_i2c->irq)
 887                 reinit_completion(&iproc_i2c->done);
 888
 889         iproc_i2c->xfer_is_done = 0;
 890
 891         /*
 892          * Enable the "start busy" interrupt, which will be triggered after the
 893          * transaction is done, i.e., the internal start_busy bit, transitions
 894          * from 1 to 0.
 895          */
 896         val_intr_en = BIT(IE_M_START_BUSY_SHIFT);
 897
 898         /*
 899          * If TX data size is larger than the TX FIFO, need to enable TX
 900          * underrun interrupt, which will be triggerred when the TX FIFO is
 901          * empty. When that happens we can then pump more data into the FIFO
 902          */
 903         if (!process_call && !(msg->flags & I2C_M_RD) &&
 904             msg->len > iproc_i2c->tx_bytes)
 905                 val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT);
 906
 907         /*
 908          * Now we can activate the transfer. For a read operation, specify the
 909          * number of bytes to read
 910          */
 911         val = BIT(M_CMD_START_BUSY_SHIFT);
 912
 913         if (msg->len == 0) {
 914                 /* SMBUS QUICK Command (Read/Write) */
 915                 val |= (M_CMD_PROTOCOL_QUICK << M_CMD_PROTOCOL_SHIFT);
 916         } else if (msg->flags & I2C_M_RD) {
 917                 u32 protocol;
 918
 919                 iproc_i2c->rx_bytes = 0;
 920                 if (msg->len > M_RX_FIFO_MAX_THLD_VALUE)
 921                         iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE;
 922                 else
 923                         iproc_i2c->thld_bytes = msg->len;
 924
 925                 /* set threshold value */
 926                 tmp = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
 927                 tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
 928                 tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT;
 929                 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, tmp);
 930
 931                 /* enable the RX threshold interrupt */
 932                 val_intr_en |= BIT(IE_M_RX_THLD_SHIFT);
 933
 934                 protocol = process_call ?
 935                                 M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD;
 936
 937                 val |= (protocol << M_CMD_PROTOCOL_SHIFT) |
 938                        (msg->len << M_CMD_RD_CNT_SHIFT);
 939         } else {
 940                 val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT);
 941         }
 942
 943         if (iproc_i2c->irq)
 944                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val_intr_en);
 945
 946         return bcm_iproc_i2c_xfer_wait(iproc_i2c, msg, val);
 947 }
 948
 949 static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
 950                               struct i2c_msg msgs[], int num)
 951 {
 952         struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter);
 953         bool process_call = false;
 954         int ret;
 955
 956         if (num == 2) {
 957                 /* Repeated start, use process call */
 958                 process_call = true;
 959                 if (msgs[1].flags & I2C_M_NOSTART) {
 960                         dev_err(iproc_i2c->device, "Invalid repeated start\n");
 961                         return -EOPNOTSUPP;
 962                 }
 963         }
 964
 965         ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call);
 966         if (ret) {
 967                 dev_dbg(iproc_i2c->device, "xfer failed\n");
 968                 return ret;
 969         }
 970
 971         return num;
 972 }
 973
 974 static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
 975 {
 976         u32 val;
 977
 978         val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 979
 980         if (adap->algo->reg_slave)
 981                 val |= I2C_FUNC_SLAVE;
 982
 983         return val;
 984 }
 985
 986 static struct i2c_algorithm bcm_iproc_algo = {
 987         .master_xfer = bcm_iproc_i2c_xfer,
 988         .functionality = bcm_iproc_i2c_functionality,
 989         .reg_slave = bcm_iproc_i2c_reg_slave,
 990         .unreg_slave = bcm_iproc_i2c_unreg_slave,
 991 };
 992
 993 static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = {
 994         .flags = I2C_AQ_COMB_WRITE_THEN_READ,
 995         .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE,
 996         .max_read_len = M_RX_MAX_READ_LEN,
 997 };
 998
 999 static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
1000 {
1001         unsigned int bus_speed;
1002         u32 val;
1003         int ret = of_property_read_u32(iproc_i2c->device->of_node,
1004                                        "clock-frequency", &bus_speed);
1005         if (ret < 0) {
1006                 dev_info(iproc_i2c->device,
1007                         "unable to interpret clock-frequency DT property\n");
1008                 bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
1009         }
1010
1011         if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) {
1012                 dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n",
1013                         bus_speed);
1014                 dev_err(iproc_i2c->device,
1015                         "valid speeds are 100khz and 400khz\n");
1016                 return -EINVAL;
1017         } else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) {
1018                 bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
1019         } else {
1020                 bus_speed = I2C_MAX_FAST_MODE_FREQ;
1021         }
1022
1023         iproc_i2c->bus_speed = bus_speed;
1024         val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1025         val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1026         val |= (bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1027         iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1028
1029         dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed);
1030
1031         return 0;
1032 }
1033
1034 static int bcm_iproc_i2c_probe(struct platform_device *pdev)
1035 {
1036         int irq, ret = 0;
1037         struct bcm_iproc_i2c_dev *iproc_i2c;
1038         struct i2c_adapter *adap;
1039         struct resource *res;
1040
1041         iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c),
1042                                  GFP_KERNEL);
1043         if (!iproc_i2c)
1044                 return -ENOMEM;
1045
1046         platform_set_drvdata(pdev, iproc_i2c);
1047         iproc_i2c->device = &pdev->dev;
1048         iproc_i2c->type =
1049                 (enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev);
1050         init_completion(&iproc_i2c->done);
1051
1052         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1053         iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res);
1054         if (IS_ERR(iproc_i2c->base))
1055                 return PTR_ERR(iproc_i2c->base);
1056
1057         if (iproc_i2c->type == IPROC_I2C_NIC) {
1058                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1059                 iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device,
1060                                                             res);
1061                 if (IS_ERR(iproc_i2c->idm_base))
1062                         return PTR_ERR(iproc_i2c->idm_base);
1063
1064                 ret = of_property_read_u32(iproc_i2c->device->of_node,
1065                                            "brcm,ape-hsls-addr-mask",
1066                                            &iproc_i2c->ape_addr_mask);
1067                 if (ret < 0) {
1068                         dev_err(iproc_i2c->device,
1069                                 "'brcm,ape-hsls-addr-mask' missing\n");
1070                         return -EINVAL;
1071                 }
1072
1073                 spin_lock_init(&iproc_i2c->idm_lock);
1074
1075                 /* no slave support */
1076                 bcm_iproc_algo.reg_slave = NULL;
1077                 bcm_iproc_algo.unreg_slave = NULL;
1078         }
1079
1080         ret = bcm_iproc_i2c_init(iproc_i2c);
1081         if (ret)
1082                 return ret;
1083
1084         ret = bcm_iproc_i2c_cfg_speed(iproc_i2c);
1085         if (ret)
1086                 return ret;
1087
1088         irq = platform_get_irq(pdev, 0);
1089         if (irq > 0) {
1090                 ret = devm_request_irq(iproc_i2c->device, irq,
1091                                        bcm_iproc_i2c_isr, 0, pdev->name,
1092                                        iproc_i2c);
1093                 if (ret < 0) {
1094                         dev_err(iproc_i2c->device,
1095                                 "unable to request irq %i\n", irq);
1096                         return ret;
1097                 }
1098
1099                 iproc_i2c->irq = irq;
1100         } else {
1101                 dev_warn(iproc_i2c->device,
1102                          "no irq resource, falling back to poll mode\n");
1103         }
1104
1105         bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1106
1107         adap = &iproc_i2c->adapter;
1108         i2c_set_adapdata(adap, iproc_i2c);
1109         snprintf(adap->name, sizeof(adap->name),
1110                 "Broadcom iProc (%s)",
1111                 of_node_full_name(iproc_i2c->device->of_node));
1112         adap->algo = &bcm_iproc_algo;
1113         adap->quirks = &bcm_iproc_i2c_quirks;
1114         adap->dev.parent = &pdev->dev;
1115         adap->dev.of_node = pdev->dev.of_node;
1116
1117         return i2c_add_adapter(adap);
1118 }
1119
1120 static int bcm_iproc_i2c_remove(struct platform_device *pdev)
1121 {
1122         struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
1123
1124         if (iproc_i2c->irq) {
1125                 /*
1126                  * Make sure there's no pending interrupt when we remove the
1127                  * adapter
1128                  */
1129                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1130                 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1131                 synchronize_irq(iproc_i2c->irq);
1132         }
1133
1134         i2c_del_adapter(&iproc_i2c->adapter);
1135         bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1136
1137         return 0;
1138 }
1139
1140 #ifdef CONFIG_PM_SLEEP
1141
1142 static int bcm_iproc_i2c_suspend(struct device *dev)
1143 {
1144         struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1145
1146         if (iproc_i2c->irq) {
1147                 /*
1148                  * Make sure there's no pending interrupt when we go into
1149                  * suspend
1150                  */
1151                 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1152                 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1153                 synchronize_irq(iproc_i2c->irq);
1154         }
1155
1156         /* now disable the controller */
1157         bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1158
1159         return 0;
1160 }
1161
1162 static int bcm_iproc_i2c_resume(struct device *dev)
1163 {
1164         struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1165         int ret;
1166         u32 val;
1167
1168         /*
1169          * Power domain could have been shut off completely in system deep
1170          * sleep, so re-initialize the block here
1171          */
1172         ret = bcm_iproc_i2c_init(iproc_i2c);
1173         if (ret)
1174                 return ret;
1175
1176         /* configure to the desired bus speed */
1177         val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1178         val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1179         val |= (iproc_i2c->bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1180         iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1181
1182         bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1183
1184         return 0;
1185 }
1186
1187 static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
1188         .suspend_late = &bcm_iproc_i2c_suspend,
1189         .resume_early = &bcm_iproc_i2c_resume
1190 };
1191
1192 #define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
1193 #else
1194 #define BCM_IPROC_I2C_PM_OPS NULL
1195 #endif /* CONFIG_PM_SLEEP */
1196
1197
1198 static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
1199 {
1200         struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1201
1202         if (iproc_i2c->slave)
1203                 return -EBUSY;
1204
1205         if (slave->flags & I2C_CLIENT_TEN)
1206                 return -EAFNOSUPPORT;
1207
1208         iproc_i2c->slave = slave;
1209
1210         tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn,
1211                      (unsigned long)iproc_i2c);
1212
1213         bcm_iproc_i2c_slave_init(iproc_i2c, false);
1214         return 0;
1215 }
1216
1217 static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
1218 {
1219         u32 tmp;
1220         struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1221
1222         if (!iproc_i2c->slave)
1223                 return -EINVAL;
1224
1225         disable_irq(iproc_i2c->irq);
1226
1227         /* disable all slave interrupts */
1228         tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1229         tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
1230                         IE_S_ALL_INTERRUPT_SHIFT);
1231         iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
1232
1233         tasklet_kill(&iproc_i2c->slave_rx_tasklet);
1234
1235         /* Erase the slave address programmed */
1236         tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
1237         tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
1238         iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp);
1239
1240         /* flush TX/RX FIFOs */
1241         tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
1242         iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp);
1243
1244         /* clear all pending slave interrupts */
1245         iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
1246
1247         iproc_i2c->slave = NULL;
1248
1249         enable_irq(iproc_i2c->irq);
1250
1251         return 0;
1252 }
1253
1254 static const struct of_device_id bcm_iproc_i2c_of_match[] = {
1255         {
1256                 .compatible = "brcm,iproc-i2c",
1257                 .data = (int *)IPROC_I2C,
1258         }, {
1259                 .compatible = "brcm,iproc-nic-i2c",
1260                 .data = (int *)IPROC_I2C_NIC,
1261         },
1262         { /* sentinel */ }
1263 };
1264 MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match);
1265
1266 static struct platform_driver bcm_iproc_i2c_driver = {
1267         .driver = {
1268                 .name = "bcm-iproc-i2c",
1269                 .of_match_table = bcm_iproc_i2c_of_match,
1270                 .pm = BCM_IPROC_I2C_PM_OPS,
1271         },
1272         .probe = bcm_iproc_i2c_probe,
1273         .remove = bcm_iproc_i2c_remove,
1274 };
1275 module_platform_driver(bcm_iproc_i2c_driver);
1276
1277 MODULE_AUTHOR("Ray Jui <[email protected]>");
1278 MODULE_DESCRIPTION("Broadcom iProc I2C Driver");
1279 MODULE_LICENSE("GPL v2");