drivers/i2c/busses/i2c-exynos5.c

   1 /**
   2  * i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver
   3  *
   4  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9 */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13
  14 #include <linux/i2c.h>
  15 #include <linux/time.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/delay.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/clk.h>
  22 #include <linux/slab.h>
  23 #include <linux/io.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_irq.h>
  26 #include <linux/spinlock.h>
  27
  28 /*
  29  * HSI2C controller from Samsung supports 2 modes of operation
  30  * 1. Auto mode: Where in master automatically controls the whole transaction
  31  * 2. Manual mode: Software controls the transaction by issuing commands
  32  *    START, READ, WRITE, STOP, RESTART in I2C_MANUAL_CMD register.
  33  *
  34  * Operation mode can be selected by setting AUTO_MODE bit in I2C_CONF register
  35  *
  36  * Special bits are available for both modes of operation to set commands
  37  * and for checking transfer status
  38  */
  39
  40 /* Register Map */
  41 #define HSI2C_CTL               0x00
  42 #define HSI2C_FIFO_CTL          0x04
  43 #define HSI2C_TRAILIG_CTL       0x08
  44 #define HSI2C_CLK_CTL           0x0C
  45 #define HSI2C_CLK_SLOT          0x10
  46 #define HSI2C_INT_ENABLE        0x20
  47 #define HSI2C_INT_STATUS        0x24
  48 #define HSI2C_ERR_STATUS        0x2C
  49 #define HSI2C_FIFO_STATUS       0x30
  50 #define HSI2C_TX_DATA           0x34
  51 #define HSI2C_RX_DATA           0x38
  52 #define HSI2C_CONF              0x40
  53 #define HSI2C_AUTO_CONF         0x44
  54 #define HSI2C_TIMEOUT           0x48
  55 #define HSI2C_MANUAL_CMD        0x4C
  56 #define HSI2C_TRANS_STATUS      0x50
  57 #define HSI2C_TIMING_HS1        0x54
  58 #define HSI2C_TIMING_HS2        0x58
  59 #define HSI2C_TIMING_HS3        0x5C
  60 #define HSI2C_TIMING_FS1        0x60
  61 #define HSI2C_TIMING_FS2        0x64
  62 #define HSI2C_TIMING_FS3        0x68
  63 #define HSI2C_TIMING_SLA        0x6C
  64 #define HSI2C_ADDR              0x70
  65
  66 /* I2C_CTL Register bits */
  67 #define HSI2C_FUNC_MODE_I2C                     (1u << 0)
  68 #define HSI2C_MASTER                            (1u << 3)
  69 #define HSI2C_RXCHON                            (1u << 6)
  70 #define HSI2C_TXCHON                            (1u << 7)
  71 #define HSI2C_SW_RST                            (1u << 31)
  72
  73 /* I2C_FIFO_CTL Register bits */
  74 #define HSI2C_RXFIFO_EN                         (1u << 0)
  75 #define HSI2C_TXFIFO_EN                         (1u << 1)
  76 #define HSI2C_RXFIFO_TRIGGER_LEVEL(x)           ((x) << 4)
  77 #define HSI2C_TXFIFO_TRIGGER_LEVEL(x)           ((x) << 16)
  78
  79 /* I2C_TRAILING_CTL Register bits */
  80 #define HSI2C_TRAILING_COUNT                    (0xf)
  81
  82 /* I2C_INT_EN Register bits */
  83 #define HSI2C_INT_TX_ALMOSTEMPTY_EN             (1u << 0)
  84 #define HSI2C_INT_RX_ALMOSTFULL_EN              (1u << 1)
  85 #define HSI2C_INT_TRAILING_EN                   (1u << 6)
  86
  87 /* I2C_INT_STAT Register bits */
  88 #define HSI2C_INT_TX_ALMOSTEMPTY                (1u << 0)
  89 #define HSI2C_INT_RX_ALMOSTFULL                 (1u << 1)
  90 #define HSI2C_INT_TX_UNDERRUN                   (1u << 2)
  91 #define HSI2C_INT_TX_OVERRUN                    (1u << 3)
  92 #define HSI2C_INT_RX_UNDERRUN                   (1u << 4)
  93 #define HSI2C_INT_RX_OVERRUN                    (1u << 5)
  94 #define HSI2C_INT_TRAILING                      (1u << 6)
  95 #define HSI2C_INT_I2C                           (1u << 9)
  96
  97 #define HSI2C_INT_TRANS_DONE                    (1u << 7)
  98 #define HSI2C_INT_TRANS_ABORT                   (1u << 8)
  99 #define HSI2C_INT_NO_DEV_ACK                    (1u << 9)
 100 #define HSI2C_INT_NO_DEV                        (1u << 10)
 101 #define HSI2C_INT_TIMEOUT                       (1u << 11)
 102 #define HSI2C_INT_I2C_TRANS                     (HSI2C_INT_TRANS_DONE | \
 103                                                 HSI2C_INT_TRANS_ABORT | \
 104                                                 HSI2C_INT_NO_DEV_ACK |  \
 105                                                 HSI2C_INT_NO_DEV |      \
 106                                                 HSI2C_INT_TIMEOUT)
 107
 108 /* I2C_FIFO_STAT Register bits */
 109 #define HSI2C_RX_FIFO_EMPTY                     (1u << 24)
 110 #define HSI2C_RX_FIFO_FULL                      (1u << 23)
 111 #define HSI2C_RX_FIFO_LVL(x)                    ((x >> 16) & 0x7f)
 112 #define HSI2C_TX_FIFO_EMPTY                     (1u << 8)
 113 #define HSI2C_TX_FIFO_FULL                      (1u << 7)
 114 #define HSI2C_TX_FIFO_LVL(x)                    ((x >> 0) & 0x7f)
 115
 116 /* I2C_CONF Register bits */
 117 #define HSI2C_AUTO_MODE                         (1u << 31)
 118 #define HSI2C_10BIT_ADDR_MODE                   (1u << 30)
 119 #define HSI2C_HS_MODE                           (1u << 29)
 120
 121 /* I2C_AUTO_CONF Register bits */
 122 #define HSI2C_READ_WRITE                        (1u << 16)
 123 #define HSI2C_STOP_AFTER_TRANS                  (1u << 17)
 124 #define HSI2C_MASTER_RUN                        (1u << 31)
 125
 126 /* I2C_TIMEOUT Register bits */
 127 #define HSI2C_TIMEOUT_EN                        (1u << 31)
 128 #define HSI2C_TIMEOUT_MASK                      0xff
 129
 130 /* I2C_TRANS_STATUS register bits */
 131 #define HSI2C_MASTER_BUSY                       (1u << 17)
 132 #define HSI2C_SLAVE_BUSY                        (1u << 16)
 133 #define HSI2C_TIMEOUT_AUTO                      (1u << 4)
 134 #define HSI2C_NO_DEV                            (1u << 3)
 135 #define HSI2C_NO_DEV_ACK                        (1u << 2)
 136 #define HSI2C_TRANS_ABORT                       (1u << 1)
 137 #define HSI2C_TRANS_DONE                        (1u << 0)
 138
 139 /* I2C_ADDR register bits */
 140 #define HSI2C_SLV_ADDR_SLV(x)                   ((x & 0x3ff) << 0)
 141 #define HSI2C_SLV_ADDR_MAS(x)                   ((x & 0x3ff) << 10)
 142 #define HSI2C_MASTER_ID(x)                      ((x & 0xff) << 24)
 143 #define MASTER_ID(x)                            ((x & 0x7) + 0x08)
 144
 145 /*
 146  * Controller operating frequency, timing values for operation
 147  * are calculated against this frequency
 148  */
 149 #define HSI2C_HS_TX_CLOCK       1000000
 150 #define HSI2C_FS_TX_CLOCK       100000
 151 #define HSI2C_HIGH_SPD          1
 152 #define HSI2C_FAST_SPD          0
 153
 154 #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
 155
 156 #define HSI2C_EXYNOS7   BIT(0)
 157
 158 struct exynos5_i2c {
 159         struct i2c_adapter      adap;
 160         unsigned int            suspended:1;
 161
 162         struct i2c_msg          *msg;
 163         struct completion       msg_complete;
 164         unsigned int            msg_ptr;
 165
 166         unsigned int            irq;
 167
 168         void __iomem            *regs;
 169         struct clk              *clk;
 170         struct device           *dev;
 171         int                     state;
 172
 173         spinlock_t              lock;           /* IRQ synchronization */
 174
 175         /*
 176          * Since the TRANS_DONE bit is cleared on read, and we may read it
 177          * either during an IRQ or after a transaction, keep track of its
 178          * state here.
 179          */
 180         int                     trans_done;
 181
 182         /* Controller operating frequency */
 183         unsigned int            fs_clock;
 184         unsigned int            hs_clock;
 185
 186         /*
 187          * HSI2C Controller can operate in
 188          * 1. High speed upto 3.4Mbps
 189          * 2. Fast speed upto 1Mbps
 190          */
 191         int                     speed_mode;
 192
 193         /* Version of HS-I2C Hardware */
 194         struct exynos_hsi2c_variant     *variant;
 195 };
 196
 197 /**
 198  * struct exynos_hsi2c_variant - platform specific HSI2C driver data
 199  * @fifo_depth: the fifo depth supported by the HSI2C module
 200  *
 201  * Specifies platform specific configuration of HSI2C module.
 202  * Note: A structure for driver specific platform data is used for future
 203  * expansion of its usage.
 204  */
 205 struct exynos_hsi2c_variant {
 206         unsigned int    fifo_depth;
 207         unsigned int    hw;
 208 };
 209
 210 static const struct exynos_hsi2c_variant exynos5250_hsi2c_data = {
 211         .fifo_depth     = 64,
 212 };
 213
 214 static const struct exynos_hsi2c_variant exynos5260_hsi2c_data = {
 215         .fifo_depth     = 16,
 216 };
 217
 218 static const struct exynos_hsi2c_variant exynos7_hsi2c_data = {
 219         .fifo_depth     = 16,
 220         .hw             = HSI2C_EXYNOS7,
 221 };
 222
 223 static const struct of_device_id exynos5_i2c_match[] = {
 224         {
 225                 .compatible = "samsung,exynos5-hsi2c",
 226                 .data = &exynos5250_hsi2c_data
 227         }, {
 228                 .compatible = "samsung,exynos5250-hsi2c",
 229                 .data = &exynos5250_hsi2c_data
 230         }, {
 231                 .compatible = "samsung,exynos5260-hsi2c",
 232                 .data = &exynos5260_hsi2c_data
 233         }, {
 234                 .compatible = "samsung,exynos7-hsi2c",
 235                 .data = &exynos7_hsi2c_data
 236         }, {},
 237 };
 238 MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
 239
 240 static inline struct exynos_hsi2c_variant *exynos5_i2c_get_variant
 241                                         (struct platform_device *pdev)
 242 {
 243         const struct of_device_id *match;
 244
 245         match = of_match_node(exynos5_i2c_match, pdev->dev.of_node);
 246         return (struct exynos_hsi2c_variant *)match->data;
 247 }
 248
 249 static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
 250 {
 251         writel(readl(i2c->regs + HSI2C_INT_STATUS),
 252                                 i2c->regs + HSI2C_INT_STATUS);
 253 }
 254
 255 /*
 256  * exynos5_i2c_set_timing: updates the registers with appropriate
 257  * timing values calculated
 258  *
 259  * Returns 0 on success, -EINVAL if the cycle length cannot
 260  * be calculated.
 261  */
 262 static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
 263 {
 264         u32 i2c_timing_s1;
 265         u32 i2c_timing_s2;
 266         u32 i2c_timing_s3;
 267         u32 i2c_timing_sla;
 268         unsigned int t_start_su, t_start_hd;
 269         unsigned int t_stop_su;
 270         unsigned int t_data_su, t_data_hd;
 271         unsigned int t_scl_l, t_scl_h;
 272         unsigned int t_sr_release;
 273         unsigned int t_ftl_cycle;
 274         unsigned int clkin = clk_get_rate(i2c->clk);
 275         unsigned int div, utemp0 = 0, utemp1 = 0, clk_cycle;
 276         unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ?
 277                                 i2c->hs_clock : i2c->fs_clock;
 278
 279         /*
 280          * In case of HSI2C controller in Exynos5 series
 281          * FPCLK / FI2C =
 282          * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
 283          *
 284          * In case of HSI2C controllers in Exynos7 series
 285          * FPCLK / FI2C =
 286          * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + FLT_CYCLE
 287          *
 288          * utemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
 289          * utemp1 = (TSCLK_L + TSCLK_H + 2)
 290          */
 291         t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
 292         utemp0 = (clkin / op_clk) - 8;
 293
 294         if (i2c->variant->hw == HSI2C_EXYNOS7)
 295                 utemp0 -= t_ftl_cycle;
 296         else
 297                 utemp0 -= 2 * t_ftl_cycle;
 298
 299         /* CLK_DIV max is 256 */
 300         for (div = 0; div < 256; div++) {
 301                 utemp1 = utemp0 / (div + 1);
 302
 303                 /*
 304                  * SCL_L and SCL_H each has max value of 255
 305                  * Hence, For the clk_cycle to the have right value
 306                  * utemp1 has to be less then 512 and more than 4.
 307                  */
 308                 if ((utemp1 < 512) && (utemp1 > 4)) {
 309                         clk_cycle = utemp1 - 2;
 310                         break;
 311                 } else if (div == 255) {
 312                         dev_warn(i2c->dev, "Failed to calculate divisor");
 313                         return -EINVAL;
 314                 }
 315         }
 316
 317         t_scl_l = clk_cycle / 2;
 318         t_scl_h = clk_cycle / 2;
 319         t_start_su = t_scl_l;
 320         t_start_hd = t_scl_l;
 321         t_stop_su = t_scl_l;
 322         t_data_su = t_scl_l / 2;
 323         t_data_hd = t_scl_l / 2;
 324         t_sr_release = clk_cycle;
 325
 326         i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
 327         i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
 328         i2c_timing_s3 = div << 16 | t_sr_release << 0;
 329         i2c_timing_sla = t_data_hd << 0;
 330
 331         dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n",
 332                 t_start_su, t_start_hd, t_stop_su);
 333         dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n",
 334                 t_data_su, t_scl_l, t_scl_h);
 335         dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n",
 336                 div, t_sr_release);
 337         dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
 338
 339         if (mode == HSI2C_HIGH_SPD) {
 340                 writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
 341                 writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
 342                 writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
 343         } else {
 344                 writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1);
 345                 writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2);
 346                 writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3);
 347         }
 348         writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA);
 349
 350         return 0;
 351 }
 352
 353 static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
 354 {
 355         /*
 356          * Configure the Fast speed timing values
 357          * Even the High Speed mode initially starts with Fast mode
 358          */
 359         if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) {
 360                 dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
 361                 return -EINVAL;
 362         }
 363
 364         /* configure the High speed timing values */
 365         if (i2c->speed_mode == HSI2C_HIGH_SPD) {
 366                 if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) {
 367                         dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
 368                         return -EINVAL;
 369                 }
 370         }
 371
 372         return 0;
 373 }
 374
 375 /*
 376  * exynos5_i2c_init: configures the controller for I2C functionality
 377  * Programs I2C controller for Master mode operation
 378  */
 379 static void exynos5_i2c_init(struct exynos5_i2c *i2c)
 380 {
 381         u32 i2c_conf = readl(i2c->regs + HSI2C_CONF);
 382         u32 i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT);
 383
 384         /* Clear to disable Timeout */
 385         i2c_timeout &= ~HSI2C_TIMEOUT_EN;
 386         writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT);
 387
 388         writel((HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
 389                                         i2c->regs + HSI2C_CTL);
 390         writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
 391
 392         if (i2c->speed_mode == HSI2C_HIGH_SPD) {
 393                 writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)),
 394                                         i2c->regs + HSI2C_ADDR);
 395                 i2c_conf |= HSI2C_HS_MODE;
 396         }
 397
 398         writel(i2c_conf | HSI2C_AUTO_MODE, i2c->regs + HSI2C_CONF);
 399 }
 400
 401 static void exynos5_i2c_reset(struct exynos5_i2c *i2c)
 402 {
 403         u32 i2c_ctl;
 404
 405         /* Set and clear the bit for reset */
 406         i2c_ctl = readl(i2c->regs + HSI2C_CTL);
 407         i2c_ctl |= HSI2C_SW_RST;
 408         writel(i2c_ctl, i2c->regs + HSI2C_CTL);
 409
 410         i2c_ctl = readl(i2c->regs + HSI2C_CTL);
 411         i2c_ctl &= ~HSI2C_SW_RST;
 412         writel(i2c_ctl, i2c->regs + HSI2C_CTL);
 413
 414         /* We don't expect calculations to fail during the run */
 415         exynos5_hsi2c_clock_setup(i2c);
 416         /* Initialize the configure registers */
 417         exynos5_i2c_init(i2c);
 418 }
 419
 420 /*
 421  * exynos5_i2c_irq: top level IRQ servicing routine
 422  *
 423  * INT_STATUS registers gives the interrupt details. Further,
 424  * FIFO_STATUS or TRANS_STATUS registers are to be check for detailed
 425  * state of the bus.
 426  */
 427 static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
 428 {
 429         struct exynos5_i2c *i2c = dev_id;
 430         u32 fifo_level, int_status, fifo_status, trans_status;
 431         unsigned char byte;
 432         int len = 0;
 433
 434         i2c->state = -EINVAL;
 435
 436         spin_lock(&i2c->lock);
 437
 438         int_status = readl(i2c->regs + HSI2C_INT_STATUS);
 439         writel(int_status, i2c->regs + HSI2C_INT_STATUS);
 440
 441         /* handle interrupt related to the transfer status */
 442         if (i2c->variant->hw == HSI2C_EXYNOS7) {
 443                 if (int_status & HSI2C_INT_TRANS_DONE) {
 444                         i2c->trans_done = 1;
 445                         i2c->state = 0;
 446                 } else if (int_status & HSI2C_INT_TRANS_ABORT) {
 447                         dev_dbg(i2c->dev, "Deal with arbitration lose\n");
 448                         i2c->state = -EAGAIN;
 449                         goto stop;
 450                 } else if (int_status & HSI2C_INT_NO_DEV_ACK) {
 451                         dev_dbg(i2c->dev, "No ACK from device\n");
 452                         i2c->state = -ENXIO;
 453                         goto stop;
 454                 } else if (int_status & HSI2C_INT_NO_DEV) {
 455                         dev_dbg(i2c->dev, "No device\n");
 456                         i2c->state = -ENXIO;
 457                         goto stop;
 458                 } else if (int_status & HSI2C_INT_TIMEOUT) {
 459                         dev_dbg(i2c->dev, "Accessing device timed out\n");
 460                         i2c->state = -ETIMEDOUT;
 461                         goto stop;
 462                 }
 463         } else if (int_status & HSI2C_INT_I2C) {
 464                 trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
 465                 if (trans_status & HSI2C_NO_DEV_ACK) {
 466                         dev_dbg(i2c->dev, "No ACK from device\n");
 467                         i2c->state = -ENXIO;
 468                         goto stop;
 469                 } else if (trans_status & HSI2C_NO_DEV) {
 470                         dev_dbg(i2c->dev, "No device\n");
 471                         i2c->state = -ENXIO;
 472                         goto stop;
 473                 } else if (trans_status & HSI2C_TRANS_ABORT) {
 474                         dev_dbg(i2c->dev, "Deal with arbitration lose\n");
 475                         i2c->state = -EAGAIN;
 476                         goto stop;
 477                 } else if (trans_status & HSI2C_TIMEOUT_AUTO) {
 478                         dev_dbg(i2c->dev, "Accessing device timed out\n");
 479                         i2c->state = -ETIMEDOUT;
 480                         goto stop;
 481                 } else if (trans_status & HSI2C_TRANS_DONE) {
 482                         i2c->trans_done = 1;
 483                         i2c->state = 0;
 484                 }
 485         }
 486
 487         if ((i2c->msg->flags & I2C_M_RD) && (int_status &
 488                         (HSI2C_INT_TRAILING | HSI2C_INT_RX_ALMOSTFULL))) {
 489                 fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
 490                 fifo_level = HSI2C_RX_FIFO_LVL(fifo_status);
 491                 len = min(fifo_level, i2c->msg->len - i2c->msg_ptr);
 492
 493                 while (len > 0) {
 494                         byte = (unsigned char)
 495                                 readl(i2c->regs + HSI2C_RX_DATA);
 496                         i2c->msg->buf[i2c->msg_ptr++] = byte;
 497                         len--;
 498                 }
 499                 i2c->state = 0;
 500         } else if (int_status & HSI2C_INT_TX_ALMOSTEMPTY) {
 501                 fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
 502                 fifo_level = HSI2C_TX_FIFO_LVL(fifo_status);
 503
 504                 len = i2c->variant->fifo_depth - fifo_level;
 505                 if (len > (i2c->msg->len - i2c->msg_ptr))
 506                         len = i2c->msg->len - i2c->msg_ptr;
 507
 508                 while (len > 0) {
 509                         byte = i2c->msg->buf[i2c->msg_ptr++];
 510                         writel(byte, i2c->regs + HSI2C_TX_DATA);
 511                         len--;
 512                 }
 513                 i2c->state = 0;
 514         }
 515
 516  stop:
 517         if ((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) ||
 518             (i2c->state < 0)) {
 519                 writel(0, i2c->regs + HSI2C_INT_ENABLE);
 520                 exynos5_i2c_clr_pend_irq(i2c);
 521                 complete(&i2c->msg_complete);
 522         }
 523
 524         spin_unlock(&i2c->lock);
 525
 526         return IRQ_HANDLED;
 527 }
 528
 529 /*
 530  * exynos5_i2c_wait_bus_idle
 531  *
 532  * Wait for the bus to go idle, indicated by the MASTER_BUSY bit being
 533  * cleared.
 534  *
 535  * Returns -EBUSY if the bus cannot be bought to idle
 536  */
 537 static int exynos5_i2c_wait_bus_idle(struct exynos5_i2c *i2c)
 538 {
 539         unsigned long stop_time;
 540         u32 trans_status;
 541
 542         /* wait for 100 milli seconds for the bus to be idle */
 543         stop_time = jiffies + msecs_to_jiffies(100) + 1;
 544         do {
 545                 trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
 546                 if (!(trans_status & HSI2C_MASTER_BUSY))
 547                         return 0;
 548
 549                 usleep_range(50, 200);
 550         } while (time_before(jiffies, stop_time));
 551
 552         return -EBUSY;
 553 }
 554
 555 /*
 556  * exynos5_i2c_message_start: Configures the bus and starts the xfer
 557  * i2c: struct exynos5_i2c pointer for the current bus
 558  * stop: Enables stop after transfer if set. Set for last transfer of
 559  *       in the list of messages.
 560  *
 561  * Configures the bus for read/write function
 562  * Sets chip address to talk to, message length to be sent.
 563  * Enables appropriate interrupts and sends start xfer command.
 564  */
 565 static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
 566 {
 567         u32 i2c_ctl;
 568         u32 int_en = 0;
 569         u32 i2c_auto_conf = 0;
 570         u32 fifo_ctl;
 571         unsigned long flags;
 572         unsigned short trig_lvl;
 573
 574         if (i2c->variant->hw == HSI2C_EXYNOS7)
 575                 int_en |= HSI2C_INT_I2C_TRANS;
 576         else
 577                 int_en |= HSI2C_INT_I2C;
 578
 579         i2c_ctl = readl(i2c->regs + HSI2C_CTL);
 580         i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
 581         fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN;
 582
 583         if (i2c->msg->flags & I2C_M_RD) {
 584                 i2c_ctl |= HSI2C_RXCHON;
 585
 586                 i2c_auto_conf |= HSI2C_READ_WRITE;
 587
 588                 trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
 589                         (i2c->variant->fifo_depth * 3 / 4) : i2c->msg->len;
 590                 fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl);
 591
 592                 int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
 593                         HSI2C_INT_TRAILING_EN);
 594         } else {
 595                 i2c_ctl |= HSI2C_TXCHON;
 596
 597                 trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
 598                         (i2c->variant->fifo_depth * 1 / 4) : i2c->msg->len;
 599                 fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl);
 600
 601                 int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
 602         }
 603
 604         writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR);
 605
 606         writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
 607         writel(i2c_ctl, i2c->regs + HSI2C_CTL);
 608
 609         /*
 610          * Enable interrupts before starting the transfer so that we don't
 611          * miss any INT_I2C interrupts.
 612          */
 613         spin_lock_irqsave(&i2c->lock, flags);
 614         writel(int_en, i2c->regs + HSI2C_INT_ENABLE);
 615
 616         if (stop == 1)
 617                 i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS;
 618         i2c_auto_conf |= i2c->msg->len;
 619         i2c_auto_conf |= HSI2C_MASTER_RUN;
 620         writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
 621         spin_unlock_irqrestore(&i2c->lock, flags);
 622 }
 623
 624 static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
 625                               struct i2c_msg *msgs, int stop)
 626 {
 627         unsigned long timeout;
 628         int ret;
 629
 630         i2c->msg = msgs;
 631         i2c->msg_ptr = 0;
 632         i2c->trans_done = 0;
 633
 634         reinit_completion(&i2c->msg_complete);
 635
 636         exynos5_i2c_message_start(i2c, stop);
 637
 638         timeout = wait_for_completion_timeout(&i2c->msg_complete,
 639                                               EXYNOS5_I2C_TIMEOUT);
 640         if (timeout == 0)
 641                 ret = -ETIMEDOUT;
 642         else
 643                 ret = i2c->state;
 644
 645         /*
 646          * If this is the last message to be transfered (stop == 1)
 647          * Then check if the bus can be brought back to idle.
 648          */
 649         if (ret == 0 && stop)
 650                 ret = exynos5_i2c_wait_bus_idle(i2c);
 651
 652         if (ret < 0) {
 653                 exynos5_i2c_reset(i2c);
 654                 if (ret == -ETIMEDOUT)
 655                         dev_warn(i2c->dev, "%s timeout\n",
 656                                  (msgs->flags & I2C_M_RD) ? "rx" : "tx");
 657         }
 658
 659         /* Return the state as in interrupt routine */
 660         return ret;
 661 }
 662
 663 static int exynos5_i2c_xfer(struct i2c_adapter *adap,
 664                         struct i2c_msg *msgs, int num)
 665 {
 666         struct exynos5_i2c *i2c = adap->algo_data;
 667         int i = 0, ret = 0, stop = 0;
 668
 669         if (i2c->suspended) {
 670                 dev_err(i2c->dev, "HS-I2C is not initialized.\n");
 671                 return -EIO;
 672         }
 673
 674         ret = clk_enable(i2c->clk);
 675         if (ret)
 676                 return ret;
 677
 678         for (i = 0; i < num; i++, msgs++) {
 679                 stop = (i == num - 1);
 680
 681                 ret = exynos5_i2c_xfer_msg(i2c, msgs, stop);
 682
 683                 if (ret < 0)
 684                         goto out;
 685         }
 686
 687         if (i == num) {
 688                 ret = num;
 689         } else {
 690                 /* Only one message, cannot access the device */
 691                 if (i == 1)
 692                         ret = -EREMOTEIO;
 693                 else
 694                         ret = i;
 695
 696                 dev_warn(i2c->dev, "xfer message failed\n");
 697         }
 698
 699  out:
 700         clk_disable(i2c->clk);
 701         return ret;
 702 }
 703
 704 static u32 exynos5_i2c_func(struct i2c_adapter *adap)
 705 {
 706         return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 707 }
 708
 709 static const struct i2c_algorithm exynos5_i2c_algorithm = {
 710         .master_xfer            = exynos5_i2c_xfer,
 711         .functionality          = exynos5_i2c_func,
 712 };
 713
 714 static int exynos5_i2c_probe(struct platform_device *pdev)
 715 {
 716         struct device_node *np = pdev->dev.of_node;
 717         struct exynos5_i2c *i2c;
 718         struct resource *mem;
 719         unsigned int op_clock;
 720         int ret;
 721
 722         i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
 723         if (!i2c)
 724                 return -ENOMEM;
 725
 726         if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
 727                 i2c->speed_mode = HSI2C_FAST_SPD;
 728                 i2c->fs_clock = HSI2C_FS_TX_CLOCK;
 729         } else {
 730                 if (op_clock >= HSI2C_HS_TX_CLOCK) {
 731                         i2c->speed_mode = HSI2C_HIGH_SPD;
 732                         i2c->fs_clock = HSI2C_FS_TX_CLOCK;
 733                         i2c->hs_clock = op_clock;
 734                 } else {
 735                         i2c->speed_mode = HSI2C_FAST_SPD;
 736                         i2c->fs_clock = op_clock;
 737                 }
 738         }
 739
 740         strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
 741         i2c->adap.owner   = THIS_MODULE;
 742         i2c->adap.algo    = &exynos5_i2c_algorithm;
 743         i2c->adap.retries = 3;
 744
 745         i2c->dev = &pdev->dev;
 746         i2c->clk = devm_clk_get(&pdev->dev, "hsi2c");
 747         if (IS_ERR(i2c->clk)) {
 748                 dev_err(&pdev->dev, "cannot get clock\n");
 749                 return -ENOENT;
 750         }
 751
 752         ret = clk_prepare_enable(i2c->clk);
 753         if (ret)
 754                 return ret;
 755
 756         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 757         i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
 758         if (IS_ERR(i2c->regs)) {
 759                 ret = PTR_ERR(i2c->regs);
 760                 goto err_clk;
 761         }
 762
 763         i2c->adap.dev.of_node = np;
 764         i2c->adap.algo_data = i2c;
 765         i2c->adap.dev.parent = &pdev->dev;
 766
 767         /* Clear pending interrupts from u-boot or misc causes */
 768         exynos5_i2c_clr_pend_irq(i2c);
 769
 770         spin_lock_init(&i2c->lock);
 771         init_completion(&i2c->msg_complete);
 772
 773         i2c->irq = ret = platform_get_irq(pdev, 0);
 774         if (ret <= 0) {
 775                 dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
 776                 ret = -EINVAL;
 777                 goto err_clk;
 778         }
 779
 780         ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
 781                                 IRQF_NO_SUSPEND | IRQF_ONESHOT,
 782                                 dev_name(&pdev->dev), i2c);
 783
 784         if (ret != 0) {
 785                 dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq);
 786                 goto err_clk;
 787         }
 788
 789         /* Need to check the variant before setting up. */
 790         i2c->variant = exynos5_i2c_get_variant(pdev);
 791
 792         ret = exynos5_hsi2c_clock_setup(i2c);
 793         if (ret)
 794                 goto err_clk;
 795
 796         exynos5_i2c_reset(i2c);
 797
 798         ret = i2c_add_adapter(&i2c->adap);
 799         if (ret < 0)
 800                 goto err_clk;
 801
 802         platform_set_drvdata(pdev, i2c);
 803
 804         clk_disable(i2c->clk);
 805
 806         return 0;
 807
 808  err_clk:
 809         clk_disable_unprepare(i2c->clk);
 810         return ret;
 811 }
 812
 813 static int exynos5_i2c_remove(struct platform_device *pdev)
 814 {
 815         struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
 816
 817         i2c_del_adapter(&i2c->adap);
 818
 819         clk_unprepare(i2c->clk);
 820
 821         return 0;
 822 }
 823
 824 #ifdef CONFIG_PM_SLEEP
 825 static int exynos5_i2c_suspend_noirq(struct device *dev)
 826 {
 827         struct platform_device *pdev = to_platform_device(dev);
 828         struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
 829
 830         i2c->suspended = 1;
 831
 832         clk_unprepare(i2c->clk);
 833
 834         return 0;
 835 }
 836
 837 static int exynos5_i2c_resume_noirq(struct device *dev)
 838 {
 839         struct platform_device *pdev = to_platform_device(dev);
 840         struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
 841         int ret = 0;
 842
 843         ret = clk_prepare_enable(i2c->clk);
 844         if (ret)
 845                 return ret;
 846
 847         ret = exynos5_hsi2c_clock_setup(i2c);
 848         if (ret) {
 849                 clk_disable_unprepare(i2c->clk);
 850                 return ret;
 851         }
 852
 853         exynos5_i2c_init(i2c);
 854         clk_disable(i2c->clk);
 855         i2c->suspended = 0;
 856
 857         return 0;
 858 }
 859 #endif
 860
 861 static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
 862         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(exynos5_i2c_suspend_noirq,
 863                                       exynos5_i2c_resume_noirq)
 864 };
 865
 866 static struct platform_driver exynos5_i2c_driver = {
 867         .probe          = exynos5_i2c_probe,
 868         .remove         = exynos5_i2c_remove,
 869         .driver         = {
 870                 .name   = "exynos5-hsi2c",
 871                 .pm     = &exynos5_i2c_dev_pm_ops,
 872                 .of_match_table = exynos5_i2c_match,
 873         },
 874 };
 875
 876 module_platform_driver(exynos5_i2c_driver);
 877
 878 MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver");
 879 MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>");
 880 MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>");
 881 MODULE_LICENSE("GPL v2");