drivers/i2c/busses/i2c-tegra.c

   1 /*
   2  * drivers/i2c/busses/i2c-tegra.c
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  * Author: Colin Cross <ccross@android.com>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/init.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/clk.h>
  22 #include <linux/err.h>
  23 #include <linux/i2c.h>
  24 #include <linux/io.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/delay.h>
  27 #include <linux/slab.h>
  28 #include <linux/of_device.h>
  29 #include <linux/module.h>
  30 #include <linux/reset.h>
  31 #include <linux/pinctrl/consumer.h>
  32 #include <linux/pm_runtime.h>
  33 #include <linux/iopoll.h>
  34
  35 #include <asm/unaligned.h>
  36
  37 #define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
  38 #define BYTES_PER_FIFO_WORD 4
  39
  40 #define I2C_CNFG                                0x000
  41 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT             12
  42 #define I2C_CNFG_PACKET_MODE_EN                 BIT(10)
  43 #define I2C_CNFG_NEW_MASTER_FSM                 BIT(11)
  44 #define I2C_CNFG_MULTI_MASTER_MODE              BIT(17)
  45 #define I2C_STATUS                              0x01C
  46 #define I2C_SL_CNFG                             0x020
  47 #define I2C_SL_CNFG_NACK                        BIT(1)
  48 #define I2C_SL_CNFG_NEWSL                       BIT(2)
  49 #define I2C_SL_ADDR1                            0x02c
  50 #define I2C_SL_ADDR2                            0x030
  51 #define I2C_TX_FIFO                             0x050
  52 #define I2C_RX_FIFO                             0x054
  53 #define I2C_PACKET_TRANSFER_STATUS              0x058
  54 #define I2C_FIFO_CONTROL                        0x05c
  55 #define I2C_FIFO_CONTROL_TX_FLUSH               BIT(1)
  56 #define I2C_FIFO_CONTROL_RX_FLUSH               BIT(0)
  57 #define I2C_FIFO_CONTROL_TX_TRIG_SHIFT          5
  58 #define I2C_FIFO_CONTROL_RX_TRIG_SHIFT          2
  59 #define I2C_FIFO_STATUS                         0x060
  60 #define I2C_FIFO_STATUS_TX_MASK                 0xF0
  61 #define I2C_FIFO_STATUS_TX_SHIFT                4
  62 #define I2C_FIFO_STATUS_RX_MASK                 0x0F
  63 #define I2C_FIFO_STATUS_RX_SHIFT                0
  64 #define I2C_INT_MASK                            0x064
  65 #define I2C_INT_STATUS                          0x068
  66 #define I2C_INT_PACKET_XFER_COMPLETE            BIT(7)
  67 #define I2C_INT_ALL_PACKETS_XFER_COMPLETE       BIT(6)
  68 #define I2C_INT_TX_FIFO_OVERFLOW                BIT(5)
  69 #define I2C_INT_RX_FIFO_UNDERFLOW               BIT(4)
  70 #define I2C_INT_NO_ACK                          BIT(3)
  71 #define I2C_INT_ARBITRATION_LOST                BIT(2)
  72 #define I2C_INT_TX_FIFO_DATA_REQ                BIT(1)
  73 #define I2C_INT_RX_FIFO_DATA_REQ                BIT(0)
  74 #define I2C_CLK_DIVISOR                         0x06c
  75 #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT     16
  76 #define I2C_CLK_MULTIPLIER_STD_FAST_MODE        8
  77
  78 #define DVC_CTRL_REG1                           0x000
  79 #define DVC_CTRL_REG1_INTR_EN                   BIT(10)
  80 #define DVC_CTRL_REG2                           0x004
  81 #define DVC_CTRL_REG3                           0x008
  82 #define DVC_CTRL_REG3_SW_PROG                   BIT(26)
  83 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN          BIT(30)
  84 #define DVC_STATUS                              0x00c
  85 #define DVC_STATUS_I2C_DONE_INTR                BIT(30)
  86
  87 #define I2C_ERR_NONE                            0x00
  88 #define I2C_ERR_NO_ACK                          0x01
  89 #define I2C_ERR_ARBITRATION_LOST                0x02
  90 #define I2C_ERR_UNKNOWN_INTERRUPT               0x04
  91
  92 #define PACKET_HEADER0_HEADER_SIZE_SHIFT        28
  93 #define PACKET_HEADER0_PACKET_ID_SHIFT          16
  94 #define PACKET_HEADER0_CONT_ID_SHIFT            12
  95 #define PACKET_HEADER0_PROTOCOL_I2C             BIT(4)
  96
  97 #define I2C_HEADER_HIGHSPEED_MODE               BIT(22)
  98 #define I2C_HEADER_CONT_ON_NAK                  BIT(21)
  99 #define I2C_HEADER_SEND_START_BYTE              BIT(20)
 100 #define I2C_HEADER_READ                         BIT(19)
 101 #define I2C_HEADER_10BIT_ADDR                   BIT(18)
 102 #define I2C_HEADER_IE_ENABLE                    BIT(17)
 103 #define I2C_HEADER_REPEAT_START                 BIT(16)
 104 #define I2C_HEADER_CONTINUE_XFER                BIT(15)
 105 #define I2C_HEADER_MASTER_ADDR_SHIFT            12
 106 #define I2C_HEADER_SLAVE_ADDR_SHIFT             1
 107
 108 #define I2C_CONFIG_LOAD                         0x08C
 109 #define I2C_MSTR_CONFIG_LOAD                    BIT(0)
 110 #define I2C_SLV_CONFIG_LOAD                     BIT(1)
 111 #define I2C_TIMEOUT_CONFIG_LOAD                 BIT(2)
 112
 113 #define I2C_CLKEN_OVERRIDE                      0x090
 114 #define I2C_MST_CORE_CLKEN_OVR                  BIT(0)
 115
 116 #define I2C_CONFIG_LOAD_TIMEOUT                 1000000
 117
 118 /*
 119  * msg_end_type: The bus control which need to be send at end of transfer.
 120  * @MSG_END_STOP: Send stop pulse at end of transfer.
 121  * @MSG_END_REPEAT_START: Send repeat start at end of transfer.
 122  * @MSG_END_CONTINUE: The following on message is coming and so do not send
 123  *              stop or repeat start.
 124  */
 125 enum msg_end_type {
 126         MSG_END_STOP,
 127         MSG_END_REPEAT_START,
 128         MSG_END_CONTINUE,
 129 };
 130
 131 /**
 132  * struct tegra_i2c_hw_feature : Different HW support on Tegra
 133  * @has_continue_xfer_support: Continue transfer supports.
 134  * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
 135  *              complete interrupt per packet basis.
 136  * @has_single_clk_source: The i2c controller has single clock source. Tegra30
 137  *              and earlier Socs has two clock sources i.e. div-clk and
 138  *              fast-clk.
 139  * @has_config_load_reg: Has the config load register to load the new
 140  *              configuration.
 141  * @clk_divisor_hs_mode: Clock divisor in HS mode.
 142  * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
 143  *              applicable if there is no fast clock source i.e. single clock
 144  *              source.
 145  */
 146
 147 struct tegra_i2c_hw_feature {
 148         bool has_continue_xfer_support;
 149         bool has_per_pkt_xfer_complete_irq;
 150         bool has_single_clk_source;
 151         bool has_config_load_reg;
 152         int clk_divisor_hs_mode;
 153         int clk_divisor_std_fast_mode;
 154         u16 clk_divisor_fast_plus_mode;
 155         bool has_multi_master_mode;
 156         bool has_slcg_override_reg;
 157 };
 158
 159 /**
 160  * struct tegra_i2c_dev - per device i2c context
 161  * @dev: device reference for power management
 162  * @hw: Tegra i2c hw feature.
 163  * @adapter: core i2c layer adapter information
 164  * @div_clk: clock reference for div clock of i2c controller.
 165  * @fast_clk: clock reference for fast clock of i2c controller.
 166  * @base: ioremapped registers cookie
 167  * @cont_id: i2c controller id, used for for packet header
 168  * @irq: irq number of transfer complete interrupt
 169  * @is_dvc: identifies the DVC i2c controller, has a different register layout
 170  * @msg_complete: transfer completion notifier
 171  * @msg_err: error code for completed message
 172  * @msg_buf: pointer to current message data
 173  * @msg_buf_remaining: size of unsent data in the message buffer
 174  * @msg_read: identifies read transfers
 175  * @bus_clk_rate: current i2c bus clock rate
 176  * @is_suspended: prevents i2c controller accesses after suspend is called
 177  */
 178 struct tegra_i2c_dev {
 179         struct device *dev;
 180         const struct tegra_i2c_hw_feature *hw;
 181         struct i2c_adapter adapter;
 182         struct clk *div_clk;
 183         struct clk *fast_clk;
 184         struct reset_control *rst;
 185         void __iomem *base;
 186         int cont_id;
 187         int irq;
 188         bool irq_disabled;
 189         int is_dvc;
 190         struct completion msg_complete;
 191         int msg_err;
 192         u8 *msg_buf;
 193         size_t msg_buf_remaining;
 194         int msg_read;
 195         u32 bus_clk_rate;
 196         u16 clk_divisor_non_hs_mode;
 197         bool is_suspended;
 198         bool is_multimaster_mode;
 199         spinlock_t xfer_lock;
 200 };
 201
 202 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
 203                        unsigned long reg)
 204 {
 205         writel(val, i2c_dev->base + reg);
 206 }
 207
 208 static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
 209 {
 210         return readl(i2c_dev->base + reg);
 211 }
 212
 213 /*
 214  * i2c_writel and i2c_readl will offset the register if necessary to talk
 215  * to the I2C block inside the DVC block
 216  */
 217 static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
 218         unsigned long reg)
 219 {
 220         if (i2c_dev->is_dvc)
 221                 reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
 222         return reg;
 223 }
 224
 225 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
 226         unsigned long reg)
 227 {
 228         writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
 229
 230         /* Read back register to make sure that register writes completed */
 231         if (reg != I2C_TX_FIFO)
 232                 readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
 233 }
 234
 235 static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
 236 {
 237         return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
 238 }
 239
 240 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
 241         unsigned long reg, int len)
 242 {
 243         writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
 244 }
 245
 246 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
 247         unsigned long reg, int len)
 248 {
 249         readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
 250 }
 251
 252 static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
 253 {
 254         u32 int_mask;
 255
 256         int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask;
 257         i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
 258 }
 259
 260 static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
 261 {
 262         u32 int_mask;
 263
 264         int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask;
 265         i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
 266 }
 267
 268 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
 269 {
 270         unsigned long timeout = jiffies + HZ;
 271         u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
 272
 273         val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
 274         i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
 275
 276         while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
 277                 (I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
 278                 if (time_after(jiffies, timeout)) {
 279                         dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
 280                         return -ETIMEDOUT;
 281                 }
 282                 msleep(1);
 283         }
 284         return 0;
 285 }
 286
 287 static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
 288 {
 289         u32 val;
 290         int rx_fifo_avail;
 291         u8 *buf = i2c_dev->msg_buf;
 292         size_t buf_remaining = i2c_dev->msg_buf_remaining;
 293         int words_to_transfer;
 294
 295         val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
 296         rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
 297                 I2C_FIFO_STATUS_RX_SHIFT;
 298
 299         /* Rounds down to not include partial word at the end of buf */
 300         words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
 301         if (words_to_transfer > rx_fifo_avail)
 302                 words_to_transfer = rx_fifo_avail;
 303
 304         i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
 305
 306         buf += words_to_transfer * BYTES_PER_FIFO_WORD;
 307         buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
 308         rx_fifo_avail -= words_to_transfer;
 309
 310         /*
 311          * If there is a partial word at the end of buf, handle it manually to
 312          * prevent overwriting past the end of buf
 313          */
 314         if (rx_fifo_avail > 0 && buf_remaining > 0) {
 315                 BUG_ON(buf_remaining > 3);
 316                 val = i2c_readl(i2c_dev, I2C_RX_FIFO);
 317                 val = cpu_to_le32(val);
 318                 memcpy(buf, &val, buf_remaining);
 319                 buf_remaining = 0;
 320                 rx_fifo_avail--;
 321         }
 322
 323         BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
 324         i2c_dev->msg_buf_remaining = buf_remaining;
 325         i2c_dev->msg_buf = buf;
 326         return 0;
 327 }
 328
 329 static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
 330 {
 331         u32 val;
 332         int tx_fifo_avail;
 333         u8 *buf = i2c_dev->msg_buf;
 334         size_t buf_remaining = i2c_dev->msg_buf_remaining;
 335         int words_to_transfer;
 336
 337         val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
 338         tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
 339                 I2C_FIFO_STATUS_TX_SHIFT;
 340
 341         /* Rounds down to not include partial word at the end of buf */
 342         words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
 343
 344         /* It's very common to have < 4 bytes, so optimize that case. */
 345         if (words_to_transfer) {
 346                 if (words_to_transfer > tx_fifo_avail)
 347                         words_to_transfer = tx_fifo_avail;
 348
 349                 /*
 350                  * Update state before writing to FIFO.  If this casues us
 351                  * to finish writing all bytes (AKA buf_remaining goes to 0) we
 352                  * have a potential for an interrupt (PACKET_XFER_COMPLETE is
 353                  * not maskable).  We need to make sure that the isr sees
 354                  * buf_remaining as 0 and doesn't call us back re-entrantly.
 355                  */
 356                 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
 357                 tx_fifo_avail -= words_to_transfer;
 358                 i2c_dev->msg_buf_remaining = buf_remaining;
 359                 i2c_dev->msg_buf = buf +
 360                         words_to_transfer * BYTES_PER_FIFO_WORD;
 361                 barrier();
 362
 363                 i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
 364
 365                 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
 366         }
 367
 368         /*
 369          * If there is a partial word at the end of buf, handle it manually to
 370          * prevent reading past the end of buf, which could cross a page
 371          * boundary and fault.
 372          */
 373         if (tx_fifo_avail > 0 && buf_remaining > 0) {
 374                 BUG_ON(buf_remaining > 3);
 375                 memcpy(&val, buf, buf_remaining);
 376                 val = le32_to_cpu(val);
 377
 378                 /* Again update before writing to FIFO to make sure isr sees. */
 379                 i2c_dev->msg_buf_remaining = 0;
 380                 i2c_dev->msg_buf = NULL;
 381                 barrier();
 382
 383                 i2c_writel(i2c_dev, val, I2C_TX_FIFO);
 384         }
 385
 386         return 0;
 387 }
 388
 389 /*
 390  * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
 391  * block.  This block is identical to the rest of the I2C blocks, except that
 392  * it only supports master mode, it has registers moved around, and it needs
 393  * some extra init to get it into I2C mode.  The register moves are handled
 394  * by i2c_readl and i2c_writel
 395  */
 396 static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
 397 {
 398         u32 val;
 399
 400         val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
 401         val |= DVC_CTRL_REG3_SW_PROG;
 402         val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
 403         dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
 404
 405         val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
 406         val |= DVC_CTRL_REG1_INTR_EN;
 407         dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
 408 }
 409
 410 static int tegra_i2c_runtime_resume(struct device *dev)
 411 {
 412         struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 413         int ret;
 414
 415         ret = pinctrl_pm_select_default_state(i2c_dev->dev);
 416         if (ret)
 417                 return ret;
 418
 419         if (!i2c_dev->hw->has_single_clk_source) {
 420                 ret = clk_enable(i2c_dev->fast_clk);
 421                 if (ret < 0) {
 422                         dev_err(i2c_dev->dev,
 423                                 "Enabling fast clk failed, err %d\n", ret);
 424                         return ret;
 425                 }
 426         }
 427
 428         ret = clk_enable(i2c_dev->div_clk);
 429         if (ret < 0) {
 430                 dev_err(i2c_dev->dev,
 431                         "Enabling div clk failed, err %d\n", ret);
 432                 clk_disable(i2c_dev->fast_clk);
 433                 return ret;
 434         }
 435
 436         return 0;
 437 }
 438
 439 static int tegra_i2c_runtime_suspend(struct device *dev)
 440 {
 441         struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 442
 443         clk_disable(i2c_dev->div_clk);
 444         if (!i2c_dev->hw->has_single_clk_source)
 445                 clk_disable(i2c_dev->fast_clk);
 446
 447         return pinctrl_pm_select_idle_state(i2c_dev->dev);
 448 }
 449
 450 static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
 451 {
 452         unsigned long reg_offset;
 453         void __iomem *addr;
 454         u32 val;
 455         int err;
 456
 457         if (i2c_dev->hw->has_config_load_reg) {
 458                 reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_CONFIG_LOAD);
 459                 addr = i2c_dev->base + reg_offset;
 460                 i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
 461                 if (in_interrupt())
 462                         err = readl_poll_timeout_atomic(addr, val, val == 0,
 463                                         1000, I2C_CONFIG_LOAD_TIMEOUT);
 464                 else
 465                         err = readl_poll_timeout(addr, val, val == 0,
 466                                         1000, I2C_CONFIG_LOAD_TIMEOUT);
 467
 468                 if (err) {
 469                         dev_warn(i2c_dev->dev,
 470                                  "timeout waiting for config load\n");
 471                         return err;
 472                 }
 473         }
 474
 475         return 0;
 476 }
 477
 478 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 479 {
 480         u32 val;
 481         int err;
 482         u32 clk_divisor;
 483
 484         err = pm_runtime_get_sync(i2c_dev->dev);
 485         if (err < 0) {
 486                 dev_err(i2c_dev->dev, "runtime resume failed %d\n", err);
 487                 return err;
 488         }
 489
 490         reset_control_assert(i2c_dev->rst);
 491         udelay(2);
 492         reset_control_deassert(i2c_dev->rst);
 493
 494         if (i2c_dev->is_dvc)
 495                 tegra_dvc_init(i2c_dev);
 496
 497         val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
 498                 (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
 499
 500         if (i2c_dev->hw->has_multi_master_mode)
 501                 val |= I2C_CNFG_MULTI_MASTER_MODE;
 502
 503         i2c_writel(i2c_dev, val, I2C_CNFG);
 504         i2c_writel(i2c_dev, 0, I2C_INT_MASK);
 505
 506         /* Make sure clock divisor programmed correctly */
 507         clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
 508         clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
 509                                         I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
 510         i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
 511
 512         if (!i2c_dev->is_dvc) {
 513                 u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
 514
 515                 sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
 516                 i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
 517                 i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
 518                 i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
 519         }
 520
 521         val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
 522                 0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
 523         i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
 524
 525         err = tegra_i2c_flush_fifos(i2c_dev);
 526         if (err)
 527                 goto err;
 528
 529         if (i2c_dev->is_multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
 530                 i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
 531
 532         err = tegra_i2c_wait_for_config_load(i2c_dev);
 533         if (err)
 534                 goto err;
 535
 536         if (i2c_dev->irq_disabled) {
 537                 i2c_dev->irq_disabled = false;
 538                 enable_irq(i2c_dev->irq);
 539         }
 540
 541 err:
 542         pm_runtime_put(i2c_dev->dev);
 543         return err;
 544 }
 545
 546 static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
 547 {
 548         u32 cnfg;
 549
 550         /*
 551          * NACK interrupt is generated before the I2C controller generates
 552          * the STOP condition on the bus. So wait for 2 clock periods
 553          * before disabling the controller so that the STOP condition has
 554          * been delivered properly.
 555          */
 556         udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
 557
 558         cnfg = i2c_readl(i2c_dev, I2C_CNFG);
 559         if (cnfg & I2C_CNFG_PACKET_MODE_EN)
 560                 i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
 561
 562         return tegra_i2c_wait_for_config_load(i2c_dev);
 563 }
 564
 565 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 566 {
 567         u32 status;
 568         const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
 569         struct tegra_i2c_dev *i2c_dev = dev_id;
 570         unsigned long flags;
 571
 572         status = i2c_readl(i2c_dev, I2C_INT_STATUS);
 573
 574         spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
 575         if (status == 0) {
 576                 dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
 577                          i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
 578                          i2c_readl(i2c_dev, I2C_STATUS),
 579                          i2c_readl(i2c_dev, I2C_CNFG));
 580                 i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
 581
 582                 if (!i2c_dev->irq_disabled) {
 583                         disable_irq_nosync(i2c_dev->irq);
 584                         i2c_dev->irq_disabled = true;
 585                 }
 586                 goto err;
 587         }
 588
 589         if (unlikely(status & status_err)) {
 590                 tegra_i2c_disable_packet_mode(i2c_dev);
 591                 if (status & I2C_INT_NO_ACK)
 592                         i2c_dev->msg_err |= I2C_ERR_NO_ACK;
 593                 if (status & I2C_INT_ARBITRATION_LOST)
 594                         i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
 595                 goto err;
 596         }
 597
 598         if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
 599                 if (i2c_dev->msg_buf_remaining)
 600                         tegra_i2c_empty_rx_fifo(i2c_dev);
 601                 else
 602                         BUG();
 603         }
 604
 605         if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
 606                 if (i2c_dev->msg_buf_remaining)
 607                         tegra_i2c_fill_tx_fifo(i2c_dev);
 608                 else
 609                         tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
 610         }
 611
 612         i2c_writel(i2c_dev, status, I2C_INT_STATUS);
 613         if (i2c_dev->is_dvc)
 614                 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
 615
 616         if (status & I2C_INT_PACKET_XFER_COMPLETE) {
 617                 BUG_ON(i2c_dev->msg_buf_remaining);
 618                 complete(&i2c_dev->msg_complete);
 619         }
 620         goto done;
 621 err:
 622         /* An error occurred, mask all interrupts */
 623         tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
 624                 I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
 625                 I2C_INT_RX_FIFO_DATA_REQ);
 626         i2c_writel(i2c_dev, status, I2C_INT_STATUS);
 627         if (i2c_dev->is_dvc)
 628                 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
 629
 630         complete(&i2c_dev->msg_complete);
 631 done:
 632         spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
 633         return IRQ_HANDLED;
 634 }
 635
 636 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 637         struct i2c_msg *msg, enum msg_end_type end_state)
 638 {
 639         u32 packet_header;
 640         u32 int_mask;
 641         unsigned long time_left;
 642         unsigned long flags;
 643
 644         tegra_i2c_flush_fifos(i2c_dev);
 645
 646         if (msg->len == 0)
 647                 return -EINVAL;
 648
 649         i2c_dev->msg_buf = msg->buf;
 650         i2c_dev->msg_buf_remaining = msg->len;
 651         i2c_dev->msg_err = I2C_ERR_NONE;
 652         i2c_dev->msg_read = (msg->flags & I2C_M_RD);
 653         reinit_completion(&i2c_dev->msg_complete);
 654
 655         spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
 656
 657         int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
 658         tegra_i2c_unmask_irq(i2c_dev, int_mask);
 659
 660         packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
 661                         PACKET_HEADER0_PROTOCOL_I2C |
 662                         (i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
 663                         (1 << PACKET_HEADER0_PACKET_ID_SHIFT);
 664         i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
 665
 666         packet_header = msg->len - 1;
 667         i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
 668
 669         packet_header = I2C_HEADER_IE_ENABLE;
 670         if (end_state == MSG_END_CONTINUE)
 671                 packet_header |= I2C_HEADER_CONTINUE_XFER;
 672         else if (end_state == MSG_END_REPEAT_START)
 673                 packet_header |= I2C_HEADER_REPEAT_START;
 674         if (msg->flags & I2C_M_TEN) {
 675                 packet_header |= msg->addr;
 676                 packet_header |= I2C_HEADER_10BIT_ADDR;
 677         } else {
 678                 packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
 679         }
 680         if (msg->flags & I2C_M_IGNORE_NAK)
 681                 packet_header |= I2C_HEADER_CONT_ON_NAK;
 682         if (msg->flags & I2C_M_RD)
 683                 packet_header |= I2C_HEADER_READ;
 684         i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
 685
 686         if (!(msg->flags & I2C_M_RD))
 687                 tegra_i2c_fill_tx_fifo(i2c_dev);
 688
 689         if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
 690                 int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
 691         if (msg->flags & I2C_M_RD)
 692                 int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
 693         else if (i2c_dev->msg_buf_remaining)
 694                 int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
 695
 696         tegra_i2c_unmask_irq(i2c_dev, int_mask);
 697         spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
 698         dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
 699                 i2c_readl(i2c_dev, I2C_INT_MASK));
 700
 701         time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
 702                                                 TEGRA_I2C_TIMEOUT);
 703         tegra_i2c_mask_irq(i2c_dev, int_mask);
 704
 705         if (time_left == 0) {
 706                 dev_err(i2c_dev->dev, "i2c transfer timed out\n");
 707
 708                 tegra_i2c_init(i2c_dev);
 709                 return -ETIMEDOUT;
 710         }
 711
 712         dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
 713                 time_left, completion_done(&i2c_dev->msg_complete),
 714                 i2c_dev->msg_err);
 715
 716         if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
 717                 return 0;
 718
 719         tegra_i2c_init(i2c_dev);
 720         if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
 721                 if (msg->flags & I2C_M_IGNORE_NAK)
 722                         return 0;
 723                 return -EREMOTEIO;
 724         }
 725
 726         return -EIO;
 727 }
 728
 729 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 730         int num)
 731 {
 732         struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
 733         int i;
 734         int ret = 0;
 735
 736         if (i2c_dev->is_suspended)
 737                 return -EBUSY;
 738
 739         ret = pm_runtime_get_sync(i2c_dev->dev);
 740         if (ret < 0) {
 741                 dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
 742                 return ret;
 743         }
 744
 745         for (i = 0; i < num; i++) {
 746                 enum msg_end_type end_type = MSG_END_STOP;
 747
 748                 if (i < (num - 1)) {
 749                         if (msgs[i + 1].flags & I2C_M_NOSTART)
 750                                 end_type = MSG_END_CONTINUE;
 751                         else
 752                                 end_type = MSG_END_REPEAT_START;
 753                 }
 754                 ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
 755                 if (ret)
 756                         break;
 757         }
 758
 759         pm_runtime_put(i2c_dev->dev);
 760
 761         return ret ?: i;
 762 }
 763
 764 static u32 tegra_i2c_func(struct i2c_adapter *adap)
 765 {
 766         struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
 767         u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
 768                   I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
 769
 770         if (i2c_dev->hw->has_continue_xfer_support)
 771                 ret |= I2C_FUNC_NOSTART;
 772         return ret;
 773 }
 774
 775 static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
 776 {
 777         struct device_node *np = i2c_dev->dev->of_node;
 778         int ret;
 779
 780         ret = of_property_read_u32(np, "clock-frequency",
 781                         &i2c_dev->bus_clk_rate);
 782         if (ret)
 783                 i2c_dev->bus_clk_rate = 100000; /* default clock rate */
 784
 785         i2c_dev->is_multimaster_mode = of_property_read_bool(np,
 786                         "multi-master");
 787 }
 788
 789 static const struct i2c_algorithm tegra_i2c_algo = {
 790         .master_xfer    = tegra_i2c_xfer,
 791         .functionality  = tegra_i2c_func,
 792 };
 793
 794 /* payload size is only 12 bit */
 795 static struct i2c_adapter_quirks tegra_i2c_quirks = {
 796         .max_read_len = 4096,
 797         .max_write_len = 4096 - 12,
 798 };
 799
 800 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
 801         .has_continue_xfer_support = false,
 802         .has_per_pkt_xfer_complete_irq = false,
 803         .has_single_clk_source = false,
 804         .clk_divisor_hs_mode = 3,
 805         .clk_divisor_std_fast_mode = 0,
 806         .clk_divisor_fast_plus_mode = 0,
 807         .has_config_load_reg = false,
 808         .has_multi_master_mode = false,
 809         .has_slcg_override_reg = false,
 810 };
 811
 812 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
 813         .has_continue_xfer_support = true,
 814         .has_per_pkt_xfer_complete_irq = false,
 815         .has_single_clk_source = false,
 816         .clk_divisor_hs_mode = 3,
 817         .clk_divisor_std_fast_mode = 0,
 818         .clk_divisor_fast_plus_mode = 0,
 819         .has_config_load_reg = false,
 820         .has_multi_master_mode = false,
 821         .has_slcg_override_reg = false,
 822 };
 823
 824 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
 825         .has_continue_xfer_support = true,
 826         .has_per_pkt_xfer_complete_irq = true,
 827         .has_single_clk_source = true,
 828         .clk_divisor_hs_mode = 1,
 829         .clk_divisor_std_fast_mode = 0x19,
 830         .clk_divisor_fast_plus_mode = 0x10,
 831         .has_config_load_reg = false,
 832         .has_multi_master_mode = false,
 833         .has_slcg_override_reg = false,
 834 };
 835
 836 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
 837         .has_continue_xfer_support = true,
 838         .has_per_pkt_xfer_complete_irq = true,
 839         .has_single_clk_source = true,
 840         .clk_divisor_hs_mode = 1,
 841         .clk_divisor_std_fast_mode = 0x19,
 842         .clk_divisor_fast_plus_mode = 0x10,
 843         .has_config_load_reg = true,
 844         .has_multi_master_mode = false,
 845         .has_slcg_override_reg = true,
 846 };
 847
 848 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
 849         .has_continue_xfer_support = true,
 850         .has_per_pkt_xfer_complete_irq = true,
 851         .has_single_clk_source = true,
 852         .clk_divisor_hs_mode = 1,
 853         .clk_divisor_std_fast_mode = 0x19,
 854         .clk_divisor_fast_plus_mode = 0x10,
 855         .has_config_load_reg = true,
 856         .has_multi_master_mode = true,
 857         .has_slcg_override_reg = true,
 858 };
 859
 860 /* Match table for of_platform binding */
 861 static const struct of_device_id tegra_i2c_of_match[] = {
 862         { .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
 863         { .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
 864         { .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
 865         { .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
 866         { .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
 867         { .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
 868         {},
 869 };
 870 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
 871
 872 static int tegra_i2c_probe(struct platform_device *pdev)
 873 {
 874         struct tegra_i2c_dev *i2c_dev;
 875         struct resource *res;
 876         struct clk *div_clk;
 877         struct clk *fast_clk;
 878         void __iomem *base;
 879         int irq;
 880         int ret = 0;
 881         int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
 882
 883         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 884         base = devm_ioremap_resource(&pdev->dev, res);
 885         if (IS_ERR(base))
 886                 return PTR_ERR(base);
 887
 888         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 889         if (!res) {
 890                 dev_err(&pdev->dev, "no irq resource\n");
 891                 return -EINVAL;
 892         }
 893         irq = res->start;
 894
 895         div_clk = devm_clk_get(&pdev->dev, "div-clk");
 896         if (IS_ERR(div_clk)) {
 897                 dev_err(&pdev->dev, "missing controller clock\n");
 898                 return PTR_ERR(div_clk);
 899         }
 900
 901         i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
 902         if (!i2c_dev)
 903                 return -ENOMEM;
 904
 905         i2c_dev->base = base;
 906         i2c_dev->div_clk = div_clk;
 907         i2c_dev->adapter.algo = &tegra_i2c_algo;
 908         i2c_dev->adapter.quirks = &tegra_i2c_quirks;
 909         i2c_dev->irq = irq;
 910         i2c_dev->cont_id = pdev->id;
 911         i2c_dev->dev = &pdev->dev;
 912
 913         i2c_dev->rst = devm_reset_control_get(&pdev->dev, "i2c");
 914         if (IS_ERR(i2c_dev->rst)) {
 915                 dev_err(&pdev->dev, "missing controller reset\n");
 916                 return PTR_ERR(i2c_dev->rst);
 917         }
 918
 919         tegra_i2c_parse_dt(i2c_dev);
 920
 921         i2c_dev->hw = of_device_get_match_data(&pdev->dev);
 922         i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
 923                                                   "nvidia,tegra20-i2c-dvc");
 924         init_completion(&i2c_dev->msg_complete);
 925         spin_lock_init(&i2c_dev->xfer_lock);
 926
 927         if (!i2c_dev->hw->has_single_clk_source) {
 928                 fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
 929                 if (IS_ERR(fast_clk)) {
 930                         dev_err(&pdev->dev, "missing fast clock\n");
 931                         return PTR_ERR(fast_clk);
 932                 }
 933                 i2c_dev->fast_clk = fast_clk;
 934         }
 935
 936         platform_set_drvdata(pdev, i2c_dev);
 937
 938         if (!i2c_dev->hw->has_single_clk_source) {
 939                 ret = clk_prepare(i2c_dev->fast_clk);
 940                 if (ret < 0) {
 941                         dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
 942                         return ret;
 943                 }
 944         }
 945
 946         i2c_dev->clk_divisor_non_hs_mode =
 947                         i2c_dev->hw->clk_divisor_std_fast_mode;
 948         if (i2c_dev->hw->clk_divisor_fast_plus_mode &&
 949                 (i2c_dev->bus_clk_rate == 1000000))
 950                 i2c_dev->clk_divisor_non_hs_mode =
 951                         i2c_dev->hw->clk_divisor_fast_plus_mode;
 952
 953         clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
 954         ret = clk_set_rate(i2c_dev->div_clk,
 955                            i2c_dev->bus_clk_rate * clk_multiplier);
 956         if (ret) {
 957                 dev_err(i2c_dev->dev, "Clock rate change failed %d\n", ret);
 958                 goto unprepare_fast_clk;
 959         }
 960
 961         ret = clk_prepare(i2c_dev->div_clk);
 962         if (ret < 0) {
 963                 dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
 964                 goto unprepare_fast_clk;
 965         }
 966
 967         pm_runtime_enable(&pdev->dev);
 968         if (!pm_runtime_enabled(&pdev->dev)) {
 969                 ret = tegra_i2c_runtime_resume(&pdev->dev);
 970                 if (ret < 0) {
 971                         dev_err(&pdev->dev, "runtime resume failed\n");
 972                         goto unprepare_div_clk;
 973                 }
 974         }
 975
 976         if (i2c_dev->is_multimaster_mode) {
 977                 ret = clk_enable(i2c_dev->div_clk);
 978                 if (ret < 0) {
 979                         dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
 980                                 ret);
 981                         goto disable_rpm;
 982                 }
 983         }
 984
 985         ret = tegra_i2c_init(i2c_dev);
 986         if (ret) {
 987                 dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
 988                 goto disable_div_clk;
 989         }
 990
 991         ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
 992                         tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
 993         if (ret) {
 994                 dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
 995                 goto disable_div_clk;
 996         }
 997
 998         i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
 999         i2c_dev->adapter.owner = THIS_MODULE;
1000         i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
1001         strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev),
1002                 sizeof(i2c_dev->adapter.name));
1003         i2c_dev->adapter.dev.parent = &pdev->dev;
1004         i2c_dev->adapter.nr = pdev->id;
1005         i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
1006
1007         ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
1008         if (ret)
1009                 goto disable_div_clk;
1010
1011         return 0;
1012
1013 disable_div_clk:
1014         if (i2c_dev->is_multimaster_mode)
1015                 clk_disable(i2c_dev->div_clk);
1016
1017 disable_rpm:
1018         pm_runtime_disable(&pdev->dev);
1019         if (!pm_runtime_status_suspended(&pdev->dev))
1020                 tegra_i2c_runtime_suspend(&pdev->dev);
1021
1022 unprepare_div_clk:
1023         clk_unprepare(i2c_dev->div_clk);
1024
1025 unprepare_fast_clk:
1026         if (!i2c_dev->hw->has_single_clk_source)
1027                 clk_unprepare(i2c_dev->fast_clk);
1028
1029         return ret;
1030 }
1031
1032 static int tegra_i2c_remove(struct platform_device *pdev)
1033 {
1034         struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1035
1036         i2c_del_adapter(&i2c_dev->adapter);
1037
1038         if (i2c_dev->is_multimaster_mode)
1039                 clk_disable(i2c_dev->div_clk);
1040
1041         pm_runtime_disable(&pdev->dev);
1042         if (!pm_runtime_status_suspended(&pdev->dev))
1043                 tegra_i2c_runtime_suspend(&pdev->dev);
1044
1045         clk_unprepare(i2c_dev->div_clk);
1046         if (!i2c_dev->hw->has_single_clk_source)
1047                 clk_unprepare(i2c_dev->fast_clk);
1048
1049         return 0;
1050 }
1051
1052 #ifdef CONFIG_PM_SLEEP
1053 static int tegra_i2c_suspend(struct device *dev)
1054 {
1055         struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1056
1057         i2c_lock_adapter(&i2c_dev->adapter);
1058         i2c_dev->is_suspended = true;
1059         i2c_unlock_adapter(&i2c_dev->adapter);
1060
1061         return 0;
1062 }
1063
1064 static int tegra_i2c_resume(struct device *dev)
1065 {
1066         struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1067         int ret;
1068
1069         i2c_lock_adapter(&i2c_dev->adapter);
1070
1071         ret = tegra_i2c_init(i2c_dev);
1072         if (!ret)
1073                 i2c_dev->is_suspended = false;
1074
1075         i2c_unlock_adapter(&i2c_dev->adapter);
1076
1077         return ret;
1078 }
1079
1080 static const struct dev_pm_ops tegra_i2c_pm = {
1081         SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
1082                            NULL)
1083         SET_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
1084 };
1085 #define TEGRA_I2C_PM    (&tegra_i2c_pm)
1086 #else
1087 #define TEGRA_I2C_PM    NULL
1088 #endif
1089
1090 static struct platform_driver tegra_i2c_driver = {
1091         .probe   = tegra_i2c_probe,
1092         .remove  = tegra_i2c_remove,
1093         .driver  = {
1094                 .name  = "tegra-i2c",
1095                 .of_match_table = tegra_i2c_of_match,
1096                 .pm    = TEGRA_I2C_PM,
1097         },
1098 };
1099
1100 static int __init tegra_i2c_init_driver(void)
1101 {
1102         return platform_driver_register(&tegra_i2c_driver);
1103 }
1104
1105 static void __exit tegra_i2c_exit_driver(void)
1106 {
1107         platform_driver_unregister(&tegra_i2c_driver);
1108 }
1109
1110 subsys_initcall(tegra_i2c_init_driver);
1111 module_exit(tegra_i2c_exit_driver);
1112
1113 MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
1114 MODULE_AUTHOR("Colin Cross");
1115 MODULE_LICENSE("GPL v2");