drivers/i2c/busses/i2c-eg20t.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/kernel.h>
   8 #include <linux/delay.h>
   9 #include <linux/errno.h>
  10 #include <linux/i2c.h>
  11 #include <linux/fs.h>
  12 #include <linux/io.h>
  13 #include <linux/types.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/pci.h>
  17 #include <linux/mutex.h>
  18 #include <linux/ktime.h>
  19 #include <linux/slab.h>
  20
  21 #define PCH_EVENT_SET   0       /* I2C Interrupt Event Set Status */
  22 #define PCH_EVENT_NONE  1       /* I2C Interrupt Event Clear Status */
  23 #define PCH_MAX_CLK             100000  /* Maximum Clock speed in MHz */
  24 #define PCH_BUFFER_MODE_ENABLE  0x0002  /* flag for Buffer mode enable */
  25 #define PCH_EEPROM_SW_RST_MODE_ENABLE   0x0008  /* EEPROM SW RST enable flag */
  26
  27 #define PCH_I2CSADR     0x00    /* I2C slave address register */
  28 #define PCH_I2CCTL      0x04    /* I2C control register */
  29 #define PCH_I2CSR       0x08    /* I2C status register */
  30 #define PCH_I2CDR       0x0C    /* I2C data register */
  31 #define PCH_I2CMON      0x10    /* I2C bus monitor register */
  32 #define PCH_I2CBC       0x14    /* I2C bus transfer rate setup counter */
  33 #define PCH_I2CMOD      0x18    /* I2C mode register */
  34 #define PCH_I2CBUFSLV   0x1C    /* I2C buffer mode slave address register */
  35 #define PCH_I2CBUFSUB   0x20    /* I2C buffer mode subaddress register */
  36 #define PCH_I2CBUFFOR   0x24    /* I2C buffer mode format register */
  37 #define PCH_I2CBUFCTL   0x28    /* I2C buffer mode control register */
  38 #define PCH_I2CBUFMSK   0x2C    /* I2C buffer mode interrupt mask register */
  39 #define PCH_I2CBUFSTA   0x30    /* I2C buffer mode status register */
  40 #define PCH_I2CBUFLEV   0x34    /* I2C buffer mode level register */
  41 #define PCH_I2CESRFOR   0x38    /* EEPROM software reset mode format register */
  42 #define PCH_I2CESRCTL   0x3C    /* EEPROM software reset mode ctrl register */
  43 #define PCH_I2CESRMSK   0x40    /* EEPROM software reset mode */
  44 #define PCH_I2CESRSTA   0x44    /* EEPROM software reset mode status register */
  45 #define PCH_I2CTMR      0x48    /* I2C timer register */
  46 #define PCH_I2CSRST     0xFC    /* I2C reset register */
  47 #define PCH_I2CNF       0xF8    /* I2C noise filter register */
  48
  49 #define BUS_IDLE_TIMEOUT        20
  50 #define PCH_I2CCTL_I2CMEN       0x0080
  51 #define TEN_BIT_ADDR_DEFAULT    0xF000
  52 #define TEN_BIT_ADDR_MASK       0xF0
  53 #define PCH_START               0x0020
  54 #define PCH_RESTART             0x0004
  55 #define PCH_ESR_START           0x0001
  56 #define PCH_BUFF_START          0x1
  57 #define PCH_REPSTART            0x0004
  58 #define PCH_ACK                 0x0008
  59 #define PCH_GETACK              0x0001
  60 #define CLR_REG                 0x0
  61 #define I2C_RD                  0x1
  62 #define I2CMCF_BIT              0x0080
  63 #define I2CMIF_BIT              0x0002
  64 #define I2CMAL_BIT              0x0010
  65 #define I2CBMFI_BIT             0x0001
  66 #define I2CBMAL_BIT             0x0002
  67 #define I2CBMNA_BIT             0x0004
  68 #define I2CBMTO_BIT             0x0008
  69 #define I2CBMIS_BIT             0x0010
  70 #define I2CESRFI_BIT            0X0001
  71 #define I2CESRTO_BIT            0x0002
  72 #define I2CESRFIIE_BIT          0x1
  73 #define I2CESRTOIE_BIT          0x2
  74 #define I2CBMDZ_BIT             0x0040
  75 #define I2CBMAG_BIT             0x0020
  76 #define I2CMBB_BIT              0x0020
  77 #define BUFFER_MODE_MASK        (I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
  78                                 I2CBMTO_BIT | I2CBMIS_BIT)
  79 #define I2C_ADDR_MSK            0xFF
  80 #define I2C_MSB_2B_MSK          0x300
  81 #define FAST_MODE_CLK           400
  82 #define FAST_MODE_EN            0x0001
  83 #define SUB_ADDR_LEN_MAX        4
  84 #define BUF_LEN_MAX             32
  85 #define PCH_BUFFER_MODE         0x1
  86 #define EEPROM_SW_RST_MODE      0x0002
  87 #define NORMAL_INTR_ENBL        0x0300
  88 #define EEPROM_RST_INTR_ENBL    (I2CESRFIIE_BIT | I2CESRTOIE_BIT)
  89 #define EEPROM_RST_INTR_DISBL   0x0
  90 #define BUFFER_MODE_INTR_ENBL   0x001F
  91 #define BUFFER_MODE_INTR_DISBL  0x0
  92 #define NORMAL_MODE             0x0
  93 #define BUFFER_MODE             0x1
  94 #define EEPROM_SR_MODE          0x2
  95 #define I2C_TX_MODE             0x0010
  96 #define PCH_BUF_TX              0xFFF7
  97 #define PCH_BUF_RD              0x0008
  98 #define I2C_ERROR_MASK  (I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
  99                         I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
 100 #define I2CMAL_EVENT            0x0001
 101 #define I2CMCF_EVENT            0x0002
 102 #define I2CBMFI_EVENT           0x0004
 103 #define I2CBMAL_EVENT           0x0008
 104 #define I2CBMNA_EVENT           0x0010
 105 #define I2CBMTO_EVENT           0x0020
 106 #define I2CBMIS_EVENT           0x0040
 107 #define I2CESRFI_EVENT          0x0080
 108 #define I2CESRTO_EVENT          0x0100
 109 #define PCI_DEVICE_ID_PCH_I2C   0x8817
 110
 111 #define pch_dbg(adap, fmt, arg...)  \
 112         dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
 113
 114 #define pch_err(adap, fmt, arg...)  \
 115         dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
 116
 117 #define pch_pci_err(pdev, fmt, arg...)  \
 118         dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
 119
 120 #define pch_pci_dbg(pdev, fmt, arg...)  \
 121         dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
 122
 123 /*
 124 Set the number of I2C instance max
 125 Intel EG20T PCH :               1ch
 126 LAPIS Semiconductor ML7213 IOH :        2ch
 127 LAPIS Semiconductor ML7831 IOH :        1ch
 128 */
 129 #define PCH_I2C_MAX_DEV                 2
 130
 131 /**
 132  * struct i2c_algo_pch_data - for I2C driver functionalities
 133  * @pch_adapter:                stores the reference to i2c_adapter structure
 134  * @p_adapter_info:             stores the reference to adapter_info structure
 135  * @pch_base_address:           specifies the remapped base address
 136  * @pch_buff_mode_en:           specifies if buffer mode is enabled
 137  * @pch_event_flag:             specifies occurrence of interrupt events
 138  * @pch_i2c_xfer_in_progress:   specifies whether the transfer is completed
 139  */
 140 struct i2c_algo_pch_data {
 141         struct i2c_adapter pch_adapter;
 142         struct adapter_info *p_adapter_info;
 143         void __iomem *pch_base_address;
 144         int pch_buff_mode_en;
 145         u32 pch_event_flag;
 146         bool pch_i2c_xfer_in_progress;
 147 };
 148
 149 /**
 150  * struct adapter_info - This structure holds the adapter information for the
 151                          PCH i2c controller
 152  * @pch_data:           stores a list of i2c_algo_pch_data
 153  * @pch_i2c_suspended:  specifies whether the system is suspended or not
 154  *                      perhaps with more lines and words.
 155  * @ch_num:             specifies the number of i2c instance
 156  *
 157  * pch_data has as many elements as maximum I2C channels
 158  */
 159 struct adapter_info {
 160         struct i2c_algo_pch_data pch_data[PCH_I2C_MAX_DEV];
 161         bool pch_i2c_suspended;
 162         int ch_num;
 163 };
 164
 165
 166 static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
 167 static int pch_clk = 50000;     /* specifies I2C clock speed in KHz */
 168 static wait_queue_head_t pch_event;
 169 static DEFINE_MUTEX(pch_mutex);
 170
 171 /* Definition for ML7213 by LAPIS Semiconductor */
 172 #define PCI_DEVICE_ID_ML7213_I2C        0x802D
 173 #define PCI_DEVICE_ID_ML7223_I2C        0x8010
 174 #define PCI_DEVICE_ID_ML7831_I2C        0x8817
 175
 176 static const struct pci_device_id pch_pcidev_id[] = {
 177         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PCH_I2C),   1, },
 178         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_I2C), 2, },
 179         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_I2C), 1, },
 180         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_I2C), 1, },
 181         {0,}
 182 };
 183
 184 static irqreturn_t pch_i2c_handler(int irq, void *pData);
 185
 186 static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
 187 {
 188         u32 val;
 189         val = ioread32(addr + offset);
 190         val |= bitmask;
 191         iowrite32(val, addr + offset);
 192 }
 193
 194 static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
 195 {
 196         u32 val;
 197         val = ioread32(addr + offset);
 198         val &= (~bitmask);
 199         iowrite32(val, addr + offset);
 200 }
 201
 202 /**
 203  * pch_i2c_init() - hardware initialization of I2C module
 204  * @adap:       Pointer to struct i2c_algo_pch_data.
 205  */
 206 static void pch_i2c_init(struct i2c_algo_pch_data *adap)
 207 {
 208         void __iomem *p = adap->pch_base_address;
 209         u32 pch_i2cbc;
 210         u32 pch_i2ctmr;
 211         u32 reg_value;
 212
 213         /* reset I2C controller */
 214         iowrite32(0x01, p + PCH_I2CSRST);
 215         msleep(20);
 216         iowrite32(0x0, p + PCH_I2CSRST);
 217
 218         /* Initialize I2C registers */
 219         iowrite32(0x21, p + PCH_I2CNF);
 220
 221         pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_I2CCTL_I2CMEN);
 222
 223         if (pch_i2c_speed != 400)
 224                 pch_i2c_speed = 100;
 225
 226         reg_value = PCH_I2CCTL_I2CMEN;
 227         if (pch_i2c_speed == FAST_MODE_CLK) {
 228                 reg_value |= FAST_MODE_EN;
 229                 pch_dbg(adap, "Fast mode enabled\n");
 230         }
 231
 232         if (pch_clk > PCH_MAX_CLK)
 233                 pch_clk = 62500;
 234
 235         pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / (pch_i2c_speed * 8);
 236         /* Set transfer speed in I2CBC */
 237         iowrite32(pch_i2cbc, p + PCH_I2CBC);
 238
 239         pch_i2ctmr = (pch_clk) / 8;
 240         iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
 241
 242         reg_value |= NORMAL_INTR_ENBL;  /* Enable interrupts in normal mode */
 243         iowrite32(reg_value, p + PCH_I2CCTL);
 244
 245         pch_dbg(adap,
 246                 "I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
 247                 ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
 248
 249         init_waitqueue_head(&pch_event);
 250 }
 251
 252 /**
 253  * pch_i2c_wait_for_bus_idle() - check the status of bus.
 254  * @adap:       Pointer to struct i2c_algo_pch_data.
 255  * @timeout:    waiting time counter (ms).
 256  */
 257 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
 258                                      s32 timeout)
 259 {
 260         void __iomem *p = adap->pch_base_address;
 261         int schedule = 0;
 262         unsigned long end = jiffies + msecs_to_jiffies(timeout);
 263
 264         while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
 265                 if (time_after(jiffies, end)) {
 266                         pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
 267                         pch_err(adap, "%s: Timeout Error.return%d\n",
 268                                         __func__, -ETIME);
 269                         pch_i2c_init(adap);
 270
 271                         return -ETIME;
 272                 }
 273
 274                 if (!schedule)
 275                         /* Retry after some usecs */
 276                         udelay(5);
 277                 else
 278                         /* Wait a bit more without consuming CPU */
 279                         usleep_range(20, 1000);
 280
 281                 schedule = 1;
 282         }
 283
 284         return 0;
 285 }
 286
 287 /**
 288  * pch_i2c_start() - Generate I2C start condition in normal mode.
 289  * @adap:       Pointer to struct i2c_algo_pch_data.
 290  *
 291  * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
 292  */
 293 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
 294 {
 295         void __iomem *p = adap->pch_base_address;
 296         pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
 297         pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
 298 }
 299
 300 /**
 301  * pch_i2c_stop() - generate stop condition in normal mode.
 302  * @adap:       Pointer to struct i2c_algo_pch_data.
 303  */
 304 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
 305 {
 306         void __iomem *p = adap->pch_base_address;
 307         pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
 308         /* clear the start bit */
 309         pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
 310 }
 311
 312 static int pch_i2c_wait_for_check_xfer(struct i2c_algo_pch_data *adap)
 313 {
 314         long ret;
 315         void __iomem *p = adap->pch_base_address;
 316
 317         ret = wait_event_timeout(pch_event,
 318                         (adap->pch_event_flag != 0), msecs_to_jiffies(1000));
 319         if (!ret) {
 320                 pch_err(adap, "%s:wait-event timeout\n", __func__);
 321                 adap->pch_event_flag = 0;
 322                 pch_i2c_stop(adap);
 323                 pch_i2c_init(adap);
 324                 return -ETIMEDOUT;
 325         }
 326
 327         if (adap->pch_event_flag & I2C_ERROR_MASK) {
 328                 pch_err(adap, "Lost Arbitration\n");
 329                 adap->pch_event_flag = 0;
 330                 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
 331                 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
 332                 pch_i2c_init(adap);
 333                 return -EAGAIN;
 334         }
 335
 336         adap->pch_event_flag = 0;
 337
 338         if (ioread32(p + PCH_I2CSR) & PCH_GETACK) {
 339                 pch_dbg(adap, "Receive NACK for slave address setting\n");
 340                 return -ENXIO;
 341         }
 342
 343         return 0;
 344 }
 345
 346 /**
 347  * pch_i2c_repstart() - generate repeated start condition in normal mode
 348  * @adap:       Pointer to struct i2c_algo_pch_data.
 349  */
 350 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
 351 {
 352         void __iomem *p = adap->pch_base_address;
 353         pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
 354         pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
 355 }
 356
 357 /**
 358  * pch_i2c_writebytes() - write data to I2C bus in normal mode
 359  * @i2c_adap:   Pointer to the struct i2c_adapter.
 360  * @last:       specifies whether last message or not.
 361  *              In the case of compound mode it will be 1 for last message,
 362  *              otherwise 0.
 363  * @first:      specifies whether first message or not.
 364  *              1 for first message otherwise 0.
 365  */
 366 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
 367                               struct i2c_msg *msgs, u32 last, u32 first)
 368 {
 369         struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
 370         u8 *buf;
 371         u32 length;
 372         u32 addr;
 373         u32 addr_2_msb;
 374         u32 addr_8_lsb;
 375         s32 wrcount;
 376         s32 rtn;
 377         void __iomem *p = adap->pch_base_address;
 378
 379         length = msgs->len;
 380         buf = msgs->buf;
 381         addr = msgs->addr;
 382
 383         /* enable master tx */
 384         pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
 385
 386         pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
 387                 length);
 388
 389         if (first) {
 390                 if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
 391                         return -ETIME;
 392         }
 393
 394         if (msgs->flags & I2C_M_TEN) {
 395                 addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7) & 0x06;
 396                 iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
 397                 if (first)
 398                         pch_i2c_start(adap);
 399
 400                 rtn = pch_i2c_wait_for_check_xfer(adap);
 401                 if (rtn)
 402                         return rtn;
 403
 404                 addr_8_lsb = (addr & I2C_ADDR_MSK);
 405                 iowrite32(addr_8_lsb, p + PCH_I2CDR);
 406         } else {
 407                 /* set 7 bit slave address and R/W bit as 0 */
 408                 iowrite32(i2c_8bit_addr_from_msg(msgs), p + PCH_I2CDR);
 409                 if (first)
 410                         pch_i2c_start(adap);
 411         }
 412
 413         rtn = pch_i2c_wait_for_check_xfer(adap);
 414         if (rtn)
 415                 return rtn;
 416
 417         for (wrcount = 0; wrcount < length; ++wrcount) {
 418                 /* write buffer value to I2C data register */
 419                 iowrite32(buf[wrcount], p + PCH_I2CDR);
 420                 pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);
 421
 422                 rtn = pch_i2c_wait_for_check_xfer(adap);
 423                 if (rtn)
 424                         return rtn;
 425
 426                 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMCF_BIT);
 427                 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
 428         }
 429
 430         /* check if this is the last message */
 431         if (last)
 432                 pch_i2c_stop(adap);
 433         else
 434                 pch_i2c_repstart(adap);
 435
 436         pch_dbg(adap, "return=%d\n", wrcount);
 437
 438         return wrcount;
 439 }
 440
 441 /**
 442  * pch_i2c_sendack() - send ACK
 443  * @adap:       Pointer to struct i2c_algo_pch_data.
 444  */
 445 static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
 446 {
 447         void __iomem *p = adap->pch_base_address;
 448         pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
 449         pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
 450 }
 451
 452 /**
 453  * pch_i2c_sendnack() - send NACK
 454  * @adap:       Pointer to struct i2c_algo_pch_data.
 455  */
 456 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
 457 {
 458         void __iomem *p = adap->pch_base_address;
 459         pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
 460         pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
 461 }
 462
 463 /**
 464  * pch_i2c_restart() - Generate I2C restart condition in normal mode.
 465  * @adap:       Pointer to struct i2c_algo_pch_data.
 466  *
 467  * Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
 468  */
 469 static void pch_i2c_restart(struct i2c_algo_pch_data *adap)
 470 {
 471         void __iomem *p = adap->pch_base_address;
 472         pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
 473         pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_RESTART);
 474 }
 475
 476 /**
 477  * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
 478  * @i2c_adap:   Pointer to the struct i2c_adapter.
 479  * @msgs:       Pointer to i2c_msg structure.
 480  * @last:       specifies whether last message or not.
 481  * @first:      specifies whether first message or not.
 482  */
 483 static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
 484                              u32 last, u32 first)
 485 {
 486         struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
 487
 488         u8 *buf;
 489         u32 count;
 490         u32 length;
 491         u32 addr;
 492         u32 addr_2_msb;
 493         u32 addr_8_lsb;
 494         void __iomem *p = adap->pch_base_address;
 495         s32 rtn;
 496
 497         length = msgs->len;
 498         buf = msgs->buf;
 499         addr = msgs->addr;
 500
 501         /* enable master reception */
 502         pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
 503
 504         if (first) {
 505                 if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
 506                         return -ETIME;
 507         }
 508
 509         if (msgs->flags & I2C_M_TEN) {
 510                 addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
 511                 iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
 512                 if (first)
 513                         pch_i2c_start(adap);
 514
 515                 rtn = pch_i2c_wait_for_check_xfer(adap);
 516                 if (rtn)
 517                         return rtn;
 518
 519                 addr_8_lsb = (addr & I2C_ADDR_MSK);
 520                 iowrite32(addr_8_lsb, p + PCH_I2CDR);
 521
 522                 pch_i2c_restart(adap);
 523
 524                 rtn = pch_i2c_wait_for_check_xfer(adap);
 525                 if (rtn)
 526                         return rtn;
 527
 528                 addr_2_msb |= I2C_RD;
 529                 iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
 530         } else {
 531                 /* 7 address bits + R/W bit */
 532                 iowrite32(i2c_8bit_addr_from_msg(msgs), p + PCH_I2CDR);
 533         }
 534
 535         /* check if it is the first message */
 536         if (first)
 537                 pch_i2c_start(adap);
 538
 539         rtn = pch_i2c_wait_for_check_xfer(adap);
 540         if (rtn)
 541                 return rtn;
 542
 543         if (length == 0) {
 544                 pch_i2c_stop(adap);
 545                 ioread32(p + PCH_I2CDR); /* Dummy read needs */
 546
 547                 count = length;
 548         } else {
 549                 int read_index;
 550                 int loop;
 551                 pch_i2c_sendack(adap);
 552
 553                 /* Dummy read */
 554                 for (loop = 1, read_index = 0; loop < length; loop++) {
 555                         buf[read_index] = ioread32(p + PCH_I2CDR);
 556
 557                         if (loop != 1)
 558                                 read_index++;
 559
 560                         rtn = pch_i2c_wait_for_check_xfer(adap);
 561                         if (rtn)
 562                                 return rtn;
 563                 }       /* end for */
 564
 565                 pch_i2c_sendnack(adap);
 566
 567                 buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
 568
 569                 if (length != 1)
 570                         read_index++;
 571
 572                 rtn = pch_i2c_wait_for_check_xfer(adap);
 573                 if (rtn)
 574                         return rtn;
 575
 576                 if (last)
 577                         pch_i2c_stop(adap);
 578                 else
 579                         pch_i2c_repstart(adap);
 580
 581                 buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
 582                 count = read_index;
 583         }
 584
 585         return count;
 586 }
 587
 588 /**
 589  * pch_i2c_cb() - Interrupt handler Call back function
 590  * @adap:       Pointer to struct i2c_algo_pch_data.
 591  */
 592 static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
 593 {
 594         u32 sts;
 595         void __iomem *p = adap->pch_base_address;
 596
 597         sts = ioread32(p + PCH_I2CSR);
 598         sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
 599         if (sts & I2CMAL_BIT)
 600                 adap->pch_event_flag |= I2CMAL_EVENT;
 601
 602         if (sts & I2CMCF_BIT)
 603                 adap->pch_event_flag |= I2CMCF_EVENT;
 604
 605         /* clear the applicable bits */
 606         pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
 607
 608         pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
 609
 610         wake_up(&pch_event);
 611 }
 612
 613 /**
 614  * pch_i2c_handler() - interrupt handler for the PCH I2C controller
 615  * @irq:        irq number.
 616  * @pData:      cookie passed back to the handler function.
 617  */
 618 static irqreturn_t pch_i2c_handler(int irq, void *pData)
 619 {
 620         u32 reg_val;
 621         int flag;
 622         int i;
 623         struct adapter_info *adap_info = pData;
 624         void __iomem *p;
 625         u32 mode;
 626
 627         for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
 628                 p = adap_info->pch_data[i].pch_base_address;
 629                 mode = ioread32(p + PCH_I2CMOD);
 630                 mode &= BUFFER_MODE | EEPROM_SR_MODE;
 631                 if (mode != NORMAL_MODE) {
 632                         pch_err(adap_info->pch_data,
 633                                 "I2C-%d mode(%d) is not supported\n", mode, i);
 634                         continue;
 635                 }
 636                 reg_val = ioread32(p + PCH_I2CSR);
 637                 if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
 638                         pch_i2c_cb(&adap_info->pch_data[i]);
 639                         flag = 1;
 640                 }
 641         }
 642
 643         return flag ? IRQ_HANDLED : IRQ_NONE;
 644 }
 645
 646 /**
 647  * pch_i2c_xfer() - Reading adnd writing data through I2C bus
 648  * @i2c_adap:   Pointer to the struct i2c_adapter.
 649  * @msgs:       Pointer to i2c_msg structure.
 650  * @num:        number of messages.
 651  */
 652 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
 653                         struct i2c_msg *msgs, s32 num)
 654 {
 655         struct i2c_msg *pmsg;
 656         u32 i = 0;
 657         u32 status;
 658         s32 ret;
 659
 660         struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
 661
 662         ret = mutex_lock_interruptible(&pch_mutex);
 663         if (ret)
 664                 return ret;
 665
 666         if (adap->p_adapter_info->pch_i2c_suspended) {
 667                 mutex_unlock(&pch_mutex);
 668                 return -EBUSY;
 669         }
 670
 671         pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
 672                 adap->p_adapter_info->pch_i2c_suspended);
 673         /* transfer not completed */
 674         adap->pch_i2c_xfer_in_progress = true;
 675
 676         for (i = 0; i < num && ret >= 0; i++) {
 677                 pmsg = &msgs[i];
 678                 pmsg->flags |= adap->pch_buff_mode_en;
 679                 status = pmsg->flags;
 680                 pch_dbg(adap,
 681                         "After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
 682
 683                 if ((status & (I2C_M_RD)) != false) {
 684                         ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
 685                                                 (i == 0));
 686                 } else {
 687                         ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
 688                                                  (i == 0));
 689                 }
 690         }
 691
 692         adap->pch_i2c_xfer_in_progress = false; /* transfer completed */
 693
 694         mutex_unlock(&pch_mutex);
 695
 696         return (ret < 0) ? ret : num;
 697 }
 698
 699 /**
 700  * pch_i2c_func() - return the functionality of the I2C driver
 701  * @adap:       Pointer to struct i2c_algo_pch_data.
 702  */
 703 static u32 pch_i2c_func(struct i2c_adapter *adap)
 704 {
 705         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 706 }
 707
 708 static const struct i2c_algorithm pch_algorithm = {
 709         .master_xfer = pch_i2c_xfer,
 710         .functionality = pch_i2c_func
 711 };
 712
 713 /**
 714  * pch_i2c_disbl_int() - Disable PCH I2C interrupts
 715  * @adap:       Pointer to struct i2c_algo_pch_data.
 716  */
 717 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
 718 {
 719         void __iomem *p = adap->pch_base_address;
 720
 721         pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
 722
 723         iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
 724
 725         iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
 726 }
 727
 728 static int pch_i2c_probe(struct pci_dev *pdev,
 729                                    const struct pci_device_id *id)
 730 {
 731         void __iomem *base_addr;
 732         int ret;
 733         int i, j;
 734         struct adapter_info *adap_info;
 735         struct i2c_adapter *pch_adap;
 736
 737         pch_pci_dbg(pdev, "Entered.\n");
 738
 739         adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
 740         if (adap_info == NULL)
 741                 return -ENOMEM;
 742
 743         ret = pci_enable_device(pdev);
 744         if (ret) {
 745                 pch_pci_err(pdev, "pci_enable_device FAILED\n");
 746                 goto err_pci_enable;
 747         }
 748
 749         ret = pci_request_regions(pdev, KBUILD_MODNAME);
 750         if (ret) {
 751                 pch_pci_err(pdev, "pci_request_regions FAILED\n");
 752                 goto err_pci_req;
 753         }
 754
 755         base_addr = pci_iomap(pdev, 1, 0);
 756
 757         if (base_addr == NULL) {
 758                 pch_pci_err(pdev, "pci_iomap FAILED\n");
 759                 ret = -ENOMEM;
 760                 goto err_pci_iomap;
 761         }
 762
 763         /* Set the number of I2C channel instance */
 764         adap_info->ch_num = id->driver_data;
 765
 766         for (i = 0; i < adap_info->ch_num; i++) {
 767                 pch_adap = &adap_info->pch_data[i].pch_adapter;
 768                 adap_info->pch_i2c_suspended = false;
 769
 770                 adap_info->pch_data[i].p_adapter_info = adap_info;
 771
 772                 pch_adap->owner = THIS_MODULE;
 773                 pch_adap->class = I2C_CLASS_HWMON;
 774                 strlcpy(pch_adap->name, KBUILD_MODNAME, sizeof(pch_adap->name));
 775                 pch_adap->algo = &pch_algorithm;
 776                 pch_adap->algo_data = &adap_info->pch_data[i];
 777
 778                 /* base_addr + offset; */
 779                 adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
 780
 781                 pch_adap->dev.of_node = pdev->dev.of_node;
 782                 pch_adap->dev.parent = &pdev->dev;
 783         }
 784
 785         ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
 786                   KBUILD_MODNAME, adap_info);
 787         if (ret) {
 788                 pch_pci_err(pdev, "request_irq FAILED\n");
 789                 goto err_request_irq;
 790         }
 791
 792         for (i = 0; i < adap_info->ch_num; i++) {
 793                 pch_adap = &adap_info->pch_data[i].pch_adapter;
 794
 795                 pch_i2c_init(&adap_info->pch_data[i]);
 796
 797                 pch_adap->nr = i;
 798                 ret = i2c_add_numbered_adapter(pch_adap);
 799                 if (ret) {
 800                         pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
 801                         goto err_add_adapter;
 802                 }
 803         }
 804
 805         pci_set_drvdata(pdev, adap_info);
 806         pch_pci_dbg(pdev, "returns %d.\n", ret);
 807         return 0;
 808
 809 err_add_adapter:
 810         for (j = 0; j < i; j++)
 811                 i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
 812         free_irq(pdev->irq, adap_info);
 813 err_request_irq:
 814         pci_iounmap(pdev, base_addr);
 815 err_pci_iomap:
 816         pci_release_regions(pdev);
 817 err_pci_req:
 818         pci_disable_device(pdev);
 819 err_pci_enable:
 820         kfree(adap_info);
 821         return ret;
 822 }
 823
 824 static void pch_i2c_remove(struct pci_dev *pdev)
 825 {
 826         int i;
 827         struct adapter_info *adap_info = pci_get_drvdata(pdev);
 828
 829         free_irq(pdev->irq, adap_info);
 830
 831         for (i = 0; i < adap_info->ch_num; i++) {
 832                 pch_i2c_disbl_int(&adap_info->pch_data[i]);
 833                 i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
 834         }
 835
 836         if (adap_info->pch_data[0].pch_base_address)
 837                 pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
 838
 839         for (i = 0; i < adap_info->ch_num; i++)
 840                 adap_info->pch_data[i].pch_base_address = NULL;
 841
 842         pci_release_regions(pdev);
 843
 844         pci_disable_device(pdev);
 845         kfree(adap_info);
 846 }
 847
 848 #ifdef CONFIG_PM
 849 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
 850 {
 851         int ret;
 852         int i;
 853         struct adapter_info *adap_info = pci_get_drvdata(pdev);
 854         void __iomem *p = adap_info->pch_data[0].pch_base_address;
 855
 856         adap_info->pch_i2c_suspended = true;
 857
 858         for (i = 0; i < adap_info->ch_num; i++) {
 859                 while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
 860                         /* Wait until all channel transfers are completed */
 861                         msleep(20);
 862                 }
 863         }
 864
 865         /* Disable the i2c interrupts */
 866         for (i = 0; i < adap_info->ch_num; i++)
 867                 pch_i2c_disbl_int(&adap_info->pch_data[i]);
 868
 869         pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
 870                 "invoked function pch_i2c_disbl_int successfully\n",
 871                 ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
 872                 ioread32(p + PCH_I2CESRSTA));
 873
 874         ret = pci_save_state(pdev);
 875
 876         if (ret) {
 877                 pch_pci_err(pdev, "pci_save_state\n");
 878                 return ret;
 879         }
 880
 881         pci_enable_wake(pdev, PCI_D3hot, 0);
 882         pci_disable_device(pdev);
 883         pci_set_power_state(pdev, pci_choose_state(pdev, state));
 884
 885         return 0;
 886 }
 887
 888 static int pch_i2c_resume(struct pci_dev *pdev)
 889 {
 890         int i;
 891         struct adapter_info *adap_info = pci_get_drvdata(pdev);
 892
 893         pci_set_power_state(pdev, PCI_D0);
 894         pci_restore_state(pdev);
 895
 896         if (pci_enable_device(pdev) < 0) {
 897                 pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
 898                 return -EIO;
 899         }
 900
 901         pci_enable_wake(pdev, PCI_D3hot, 0);
 902
 903         for (i = 0; i < adap_info->ch_num; i++)
 904                 pch_i2c_init(&adap_info->pch_data[i]);
 905
 906         adap_info->pch_i2c_suspended = false;
 907
 908         return 0;
 909 }
 910 #else
 911 #define pch_i2c_suspend NULL
 912 #define pch_i2c_resume NULL
 913 #endif
 914
 915 static struct pci_driver pch_pcidriver = {
 916         .name = KBUILD_MODNAME,
 917         .id_table = pch_pcidev_id,
 918         .probe = pch_i2c_probe,
 919         .remove = pch_i2c_remove,
 920         .suspend = pch_i2c_suspend,
 921         .resume = pch_i2c_resume
 922 };
 923
 924 module_pci_driver(pch_pcidriver);
 925
 926 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
 927 MODULE_LICENSE("GPL");
 928 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya.rohm@gmail.com>");
 929 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
 930 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));