linux/drivers/i2c/busses/i2c-omap.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * TI OMAP I2C master mode driver
   4 *
   5 * Copyright (C) 2003 MontaVista Software, Inc.
   6 * Copyright (C) 2005 Nokia Corporation
   7 * Copyright (C) 2004 - 2007 Texas Instruments.
   8 *
   9 * Originally written by MontaVista Software, Inc.
  10 * Additional contributions by:
  11 *      Tony Lindgren <tony@atomide.com>
  12 *      Imre Deak <imre.deak@nokia.com>
  13 *      Juha Yrjölä <juha.yrjola@solidboot.com>
  14 *      Syed Khasim <x0khasim@ti.com>
  15 *      Nishant Menon <nm@ti.com>
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/delay.h>
  20#include <linux/i2c.h>
  21#include <linux/err.h>
  22#include <linux/interrupt.h>
  23#include <linux/completion.h>
  24#include <linux/platform_device.h>
  25#include <linux/clk.h>
  26#include <linux/io.h>
  27#include <linux/of.h>
  28#include <linux/of_device.h>
  29#include <linux/slab.h>
  30#include <linux/platform_data/i2c-omap.h>
  31#include <linux/pm_runtime.h>
  32#include <linux/pinctrl/consumer.h>
  33
  34/* I2C controller revisions */
  35#define OMAP_I2C_OMAP1_REV_2            0x20
  36
  37/* I2C controller revisions present on specific hardware */
  38#define OMAP_I2C_REV_ON_2430            0x00000036
  39#define OMAP_I2C_REV_ON_3430_3530       0x0000003C
  40#define OMAP_I2C_REV_ON_3630            0x00000040
  41#define OMAP_I2C_REV_ON_4430_PLUS       0x50400002
  42
  43/* timeout waiting for the controller to respond */
  44#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
  45
  46/* timeout for pm runtime autosuspend */
  47#define OMAP_I2C_PM_TIMEOUT             1000    /* ms */
  48
  49/* timeout for making decision on bus free status */
  50#define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10))
  51
  52/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
  53enum {
  54        OMAP_I2C_REV_REG = 0,
  55        OMAP_I2C_IE_REG,
  56        OMAP_I2C_STAT_REG,
  57        OMAP_I2C_IV_REG,
  58        OMAP_I2C_WE_REG,
  59        OMAP_I2C_SYSS_REG,
  60        OMAP_I2C_BUF_REG,
  61        OMAP_I2C_CNT_REG,
  62        OMAP_I2C_DATA_REG,
  63        OMAP_I2C_SYSC_REG,
  64        OMAP_I2C_CON_REG,
  65        OMAP_I2C_OA_REG,
  66        OMAP_I2C_SA_REG,
  67        OMAP_I2C_PSC_REG,
  68        OMAP_I2C_SCLL_REG,
  69        OMAP_I2C_SCLH_REG,
  70        OMAP_I2C_SYSTEST_REG,
  71        OMAP_I2C_BUFSTAT_REG,
  72        /* only on OMAP4430 */
  73        OMAP_I2C_IP_V2_REVNB_LO,
  74        OMAP_I2C_IP_V2_REVNB_HI,
  75        OMAP_I2C_IP_V2_IRQSTATUS_RAW,
  76        OMAP_I2C_IP_V2_IRQENABLE_SET,
  77        OMAP_I2C_IP_V2_IRQENABLE_CLR,
  78};
  79
  80/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
  81#define OMAP_I2C_IE_XDR         (1 << 14)       /* TX Buffer drain int enable */
  82#define OMAP_I2C_IE_RDR         (1 << 13)       /* RX Buffer drain int enable */
  83#define OMAP_I2C_IE_XRDY        (1 << 4)        /* TX data ready int enable */
  84#define OMAP_I2C_IE_RRDY        (1 << 3)        /* RX data ready int enable */
  85#define OMAP_I2C_IE_ARDY        (1 << 2)        /* Access ready int enable */
  86#define OMAP_I2C_IE_NACK        (1 << 1)        /* No ack interrupt enable */
  87#define OMAP_I2C_IE_AL          (1 << 0)        /* Arbitration lost int ena */
  88
  89/* I2C Status Register (OMAP_I2C_STAT): */
  90#define OMAP_I2C_STAT_XDR       (1 << 14)       /* TX Buffer draining */
  91#define OMAP_I2C_STAT_RDR       (1 << 13)       /* RX Buffer draining */
  92#define OMAP_I2C_STAT_BB        (1 << 12)       /* Bus busy */
  93#define OMAP_I2C_STAT_ROVR      (1 << 11)       /* Receive overrun */
  94#define OMAP_I2C_STAT_XUDF      (1 << 10)       /* Transmit underflow */
  95#define OMAP_I2C_STAT_AAS       (1 << 9)        /* Address as slave */
  96#define OMAP_I2C_STAT_BF        (1 << 8)        /* Bus Free */
  97#define OMAP_I2C_STAT_XRDY      (1 << 4)        /* Transmit data ready */
  98#define OMAP_I2C_STAT_RRDY      (1 << 3)        /* Receive data ready */
  99#define OMAP_I2C_STAT_ARDY      (1 << 2)        /* Register access ready */
 100#define OMAP_I2C_STAT_NACK      (1 << 1)        /* No ack interrupt enable */
 101#define OMAP_I2C_STAT_AL        (1 << 0)        /* Arbitration lost int ena */
 102
 103/* I2C WE wakeup enable register */
 104#define OMAP_I2C_WE_XDR_WE      (1 << 14)       /* TX drain wakup */
 105#define OMAP_I2C_WE_RDR_WE      (1 << 13)       /* RX drain wakeup */
 106#define OMAP_I2C_WE_AAS_WE      (1 << 9)        /* Address as slave wakeup*/
 107#define OMAP_I2C_WE_BF_WE       (1 << 8)        /* Bus free wakeup */
 108#define OMAP_I2C_WE_STC_WE      (1 << 6)        /* Start condition wakeup */
 109#define OMAP_I2C_WE_GC_WE       (1 << 5)        /* General call wakeup */
 110#define OMAP_I2C_WE_DRDY_WE     (1 << 3)        /* TX/RX data ready wakeup */
 111#define OMAP_I2C_WE_ARDY_WE     (1 << 2)        /* Reg access ready wakeup */
 112#define OMAP_I2C_WE_NACK_WE     (1 << 1)        /* No acknowledgment wakeup */
 113#define OMAP_I2C_WE_AL_WE       (1 << 0)        /* Arbitration lost wakeup */
 114
 115#define OMAP_I2C_WE_ALL         (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
 116                                OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
 117                                OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
 118                                OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
 119                                OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
 120
 121/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
 122#define OMAP_I2C_BUF_RDMA_EN    (1 << 15)       /* RX DMA channel enable */
 123#define OMAP_I2C_BUF_RXFIF_CLR  (1 << 14)       /* RX FIFO Clear */
 124#define OMAP_I2C_BUF_XDMA_EN    (1 << 7)        /* TX DMA channel enable */
 125#define OMAP_I2C_BUF_TXFIF_CLR  (1 << 6)        /* TX FIFO Clear */
 126
 127/* I2C Configuration Register (OMAP_I2C_CON): */
 128#define OMAP_I2C_CON_EN         (1 << 15)       /* I2C module enable */
 129#define OMAP_I2C_CON_BE         (1 << 14)       /* Big endian mode */
 130#define OMAP_I2C_CON_OPMODE_HS  (1 << 12)       /* High Speed support */
 131#define OMAP_I2C_CON_STB        (1 << 11)       /* Start byte mode (master) */
 132#define OMAP_I2C_CON_MST        (1 << 10)       /* Master/slave mode */
 133#define OMAP_I2C_CON_TRX        (1 << 9)        /* TX/RX mode (master only) */
 134#define OMAP_I2C_CON_XA         (1 << 8)        /* Expand address */
 135#define OMAP_I2C_CON_RM         (1 << 2)        /* Repeat mode (master only) */
 136#define OMAP_I2C_CON_STP        (1 << 1)        /* Stop cond (master only) */
 137#define OMAP_I2C_CON_STT        (1 << 0)        /* Start condition (master) */
 138
 139/* I2C SCL time value when Master */
 140#define OMAP_I2C_SCLL_HSSCLL    8
 141#define OMAP_I2C_SCLH_HSSCLH    8
 142
 143/* I2C System Test Register (OMAP_I2C_SYSTEST): */
 144#define OMAP_I2C_SYSTEST_ST_EN          (1 << 15)       /* System test enable */
 145#define OMAP_I2C_SYSTEST_FREE           (1 << 14)       /* Free running mode */
 146#define OMAP_I2C_SYSTEST_TMODE_MASK     (3 << 12)       /* Test mode select */
 147#define OMAP_I2C_SYSTEST_TMODE_SHIFT    (12)            /* Test mode select */
 148/* Functional mode */
 149#define OMAP_I2C_SYSTEST_SCL_I_FUNC     (1 << 8)        /* SCL line input value */
 150#define OMAP_I2C_SYSTEST_SCL_O_FUNC     (1 << 7)        /* SCL line output value */
 151#define OMAP_I2C_SYSTEST_SDA_I_FUNC     (1 << 6)        /* SDA line input value */
 152#define OMAP_I2C_SYSTEST_SDA_O_FUNC     (1 << 5)        /* SDA line output value */
 153/* SDA/SCL IO mode */
 154#define OMAP_I2C_SYSTEST_SCL_I          (1 << 3)        /* SCL line sense in */
 155#define OMAP_I2C_SYSTEST_SCL_O          (1 << 2)        /* SCL line drive out */
 156#define OMAP_I2C_SYSTEST_SDA_I          (1 << 1)        /* SDA line sense in */
 157#define OMAP_I2C_SYSTEST_SDA_O          (1 << 0)        /* SDA line drive out */
 158
 159/* OCP_SYSSTATUS bit definitions */
 160#define SYSS_RESETDONE_MASK             (1 << 0)
 161
 162/* OCP_SYSCONFIG bit definitions */
 163#define SYSC_CLOCKACTIVITY_MASK         (0x3 << 8)
 164#define SYSC_SIDLEMODE_MASK             (0x3 << 3)
 165#define SYSC_ENAWAKEUP_MASK             (1 << 2)
 166#define SYSC_SOFTRESET_MASK             (1 << 1)
 167#define SYSC_AUTOIDLE_MASK              (1 << 0)
 168
 169#define SYSC_IDLEMODE_SMART             0x2
 170#define SYSC_CLOCKACTIVITY_FCLK         0x2
 171
 172/* Errata definitions */
 173#define I2C_OMAP_ERRATA_I207            (1 << 0)
 174#define I2C_OMAP_ERRATA_I462            (1 << 1)
 175
 176#define OMAP_I2C_IP_V2_INTERRUPTS_MASK  0x6FFF
 177
 178struct omap_i2c_dev {
 179        struct device           *dev;
 180        void __iomem            *base;          /* virtual */
 181        int                     irq;
 182        int                     reg_shift;      /* bit shift for I2C register addresses */
 183        struct completion       cmd_complete;
 184        struct resource         *ioarea;
 185        u32                     latency;        /* maximum mpu wkup latency */
 186        void                    (*set_mpu_wkup_lat)(struct device *dev,
 187                                                    long latency);
 188        u32                     speed;          /* Speed of bus in kHz */
 189        u32                     flags;
 190        u16                     scheme;
 191        u16                     cmd_err;
 192        u8                      *buf;
 193        u8                      *regs;
 194        size_t                  buf_len;
 195        struct i2c_adapter      adapter;
 196        u8                      threshold;
 197        u8                      fifo_size;      /* use as flag and value
 198                                                 * fifo_size==0 implies no fifo
 199                                                 * if set, should be trsh+1
 200                                                 */
 201        u32                     rev;
 202        unsigned                b_hw:1;         /* bad h/w fixes */
 203        unsigned                bb_valid:1;     /* true when BB-bit reflects
 204                                                 * the I2C bus state
 205                                                 */
 206        unsigned                receiver:1;     /* true when we're in receiver mode */
 207        u16                     iestate;        /* Saved interrupt register */
 208        u16                     pscstate;
 209        u16                     scllstate;
 210        u16                     sclhstate;
 211        u16                     syscstate;
 212        u16                     westate;
 213        u16                     errata;
 214};
 215
 216static const u8 reg_map_ip_v1[] = {
 217        [OMAP_I2C_REV_REG] = 0x00,
 218        [OMAP_I2C_IE_REG] = 0x01,
 219        [OMAP_I2C_STAT_REG] = 0x02,
 220        [OMAP_I2C_IV_REG] = 0x03,
 221        [OMAP_I2C_WE_REG] = 0x03,
 222        [OMAP_I2C_SYSS_REG] = 0x04,
 223        [OMAP_I2C_BUF_REG] = 0x05,
 224        [OMAP_I2C_CNT_REG] = 0x06,
 225        [OMAP_I2C_DATA_REG] = 0x07,
 226        [OMAP_I2C_SYSC_REG] = 0x08,
 227        [OMAP_I2C_CON_REG] = 0x09,
 228        [OMAP_I2C_OA_REG] = 0x0a,
 229        [OMAP_I2C_SA_REG] = 0x0b,
 230        [OMAP_I2C_PSC_REG] = 0x0c,
 231        [OMAP_I2C_SCLL_REG] = 0x0d,
 232        [OMAP_I2C_SCLH_REG] = 0x0e,
 233        [OMAP_I2C_SYSTEST_REG] = 0x0f,
 234        [OMAP_I2C_BUFSTAT_REG] = 0x10,
 235};
 236
 237static const u8 reg_map_ip_v2[] = {
 238        [OMAP_I2C_REV_REG] = 0x04,
 239        [OMAP_I2C_IE_REG] = 0x2c,
 240        [OMAP_I2C_STAT_REG] = 0x28,
 241        [OMAP_I2C_IV_REG] = 0x34,
 242        [OMAP_I2C_WE_REG] = 0x34,
 243        [OMAP_I2C_SYSS_REG] = 0x90,
 244        [OMAP_I2C_BUF_REG] = 0x94,
 245        [OMAP_I2C_CNT_REG] = 0x98,
 246        [OMAP_I2C_DATA_REG] = 0x9c,
 247        [OMAP_I2C_SYSC_REG] = 0x10,
 248        [OMAP_I2C_CON_REG] = 0xa4,
 249        [OMAP_I2C_OA_REG] = 0xa8,
 250        [OMAP_I2C_SA_REG] = 0xac,
 251        [OMAP_I2C_PSC_REG] = 0xb0,
 252        [OMAP_I2C_SCLL_REG] = 0xb4,
 253        [OMAP_I2C_SCLH_REG] = 0xb8,
 254        [OMAP_I2C_SYSTEST_REG] = 0xbC,
 255        [OMAP_I2C_BUFSTAT_REG] = 0xc0,
 256        [OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
 257        [OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
 258        [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
 259        [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
 260        [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
 261};
 262
 263static int omap_i2c_xfer_data(struct omap_i2c_dev *omap);
 264
 265static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap,
 266                                      int reg, u16 val)
 267{
 268        writew_relaxed(val, omap->base +
 269                        (omap->regs[reg] << omap->reg_shift));
 270}
 271
 272static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg)
 273{
 274        return readw_relaxed(omap->base +
 275                                (omap->regs[reg] << omap->reg_shift));
 276}
 277
 278static void __omap_i2c_init(struct omap_i2c_dev *omap)
 279{
 280
 281        omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
 282
 283        /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
 284        omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate);
 285
 286        /* SCL low and high time values */
 287        omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate);
 288        omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate);
 289        if (omap->rev >= OMAP_I2C_REV_ON_3430_3530)
 290                omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate);
 291
 292        /* Take the I2C module out of reset: */
 293        omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
 294
 295        /*
 296         * NOTE: right after setting CON_EN, STAT_BB could be 0 while the
 297         * bus is busy. It will be changed to 1 on the next IP FCLK clock.
 298         * udelay(1) will be enough to fix that.
 299         */
 300
 301        /*
 302         * Don't write to this register if the IE state is 0 as it can
 303         * cause deadlock.
 304         */
 305        if (omap->iestate)
 306                omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate);
 307}
 308
 309static int omap_i2c_reset(struct omap_i2c_dev *omap)
 310{
 311        unsigned long timeout;
 312        u16 sysc;
 313
 314        if (omap->rev >= OMAP_I2C_OMAP1_REV_2) {
 315                sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG);
 316
 317                /* Disable I2C controller before soft reset */
 318                omap_i2c_write_reg(omap, OMAP_I2C_CON_REG,
 319                        omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) &
 320                                ~(OMAP_I2C_CON_EN));
 321
 322                omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
 323                /* For some reason we need to set the EN bit before the
 324                 * reset done bit gets set. */
 325                timeout = jiffies + OMAP_I2C_TIMEOUT;
 326                omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
 327                while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) &
 328                         SYSS_RESETDONE_MASK)) {
 329                        if (time_after(jiffies, timeout)) {
 330                                dev_warn(omap->dev, "timeout waiting "
 331                                                "for controller reset\n");
 332                                return -ETIMEDOUT;
 333                        }
 334                        msleep(1);
 335                }
 336
 337                /* SYSC register is cleared by the reset; rewrite it */
 338                omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc);
 339
 340                if (omap->rev > OMAP_I2C_REV_ON_3430_3530) {
 341                        /* Schedule I2C-bus monitoring on the next transfer */
 342                        omap->bb_valid = 0;
 343                }
 344        }
 345
 346        return 0;
 347}
 348
 349static int omap_i2c_init(struct omap_i2c_dev *omap)
 350{
 351        u16 psc = 0, scll = 0, sclh = 0;
 352        u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
 353        unsigned long fclk_rate = 12000000;
 354        unsigned long internal_clk = 0;
 355        struct clk *fclk;
 356        int error;
 357
 358        if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) {
 359                /*
 360                 * Enabling all wakup sources to stop I2C freezing on
 361                 * WFI instruction.
 362                 * REVISIT: Some wkup sources might not be needed.
 363                 */
 364                omap->westate = OMAP_I2C_WE_ALL;
 365        }
 366
 367        if (omap->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
 368                /*
 369                 * The I2C functional clock is the armxor_ck, so there's
 370                 * no need to get "armxor_ck" separately.  Now, if OMAP2420
 371                 * always returns 12MHz for the functional clock, we can
 372                 * do this bit unconditionally.
 373                 */
 374                fclk = clk_get(omap->dev, "fck");
 375                if (IS_ERR(fclk)) {
 376                        error = PTR_ERR(fclk);
 377                        dev_err(omap->dev, "could not get fck: %i\n", error);
 378
 379                        return error;
 380                }
 381
 382                fclk_rate = clk_get_rate(fclk);
 383                clk_put(fclk);
 384
 385                /* TRM for 5912 says the I2C clock must be prescaled to be
 386                 * between 7 - 12 MHz. The XOR input clock is typically
 387                 * 12, 13 or 19.2 MHz. So we should have code that produces:
 388                 *
 389                 * XOR MHz      Divider         Prescaler
 390                 * 12           1               0
 391                 * 13           2               1
 392                 * 19.2         2               1
 393                 */
 394                if (fclk_rate > 12000000)
 395                        psc = fclk_rate / 12000000;
 396        }
 397
 398        if (!(omap->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
 399
 400                /*
 401                 * HSI2C controller internal clk rate should be 19.2 Mhz for
 402                 * HS and for all modes on 2430. On 34xx we can use lower rate
 403                 * to get longer filter period for better noise suppression.
 404                 * The filter is iclk (fclk for HS) period.
 405                 */
 406                if (omap->speed > 400 ||
 407                               omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
 408                        internal_clk = 19200;
 409                else if (omap->speed > 100)
 410                        internal_clk = 9600;
 411                else
 412                        internal_clk = 4000;
 413                fclk = clk_get(omap->dev, "fck");
 414                if (IS_ERR(fclk)) {
 415                        error = PTR_ERR(fclk);
 416                        dev_err(omap->dev, "could not get fck: %i\n", error);
 417
 418                        return error;
 419                }
 420                fclk_rate = clk_get_rate(fclk) / 1000;
 421                clk_put(fclk);
 422
 423                /* Compute prescaler divisor */
 424                psc = fclk_rate / internal_clk;
 425                psc = psc - 1;
 426
 427                /* If configured for High Speed */
 428                if (omap->speed > 400) {
 429                        unsigned long scl;
 430
 431                        /* For first phase of HS mode */
 432                        scl = internal_clk / 400;
 433                        fsscll = scl - (scl / 3) - 7;
 434                        fssclh = (scl / 3) - 5;
 435
 436                        /* For second phase of HS mode */
 437                        scl = fclk_rate / omap->speed;
 438                        hsscll = scl - (scl / 3) - 7;
 439                        hssclh = (scl / 3) - 5;
 440                } else if (omap->speed > 100) {
 441                        unsigned long scl;
 442
 443                        /* Fast mode */
 444                        scl = internal_clk / omap->speed;
 445                        fsscll = scl - (scl / 3) - 7;
 446                        fssclh = (scl / 3) - 5;
 447                } else {
 448                        /* Standard mode */
 449                        fsscll = internal_clk / (omap->speed * 2) - 7;
 450                        fssclh = internal_clk / (omap->speed * 2) - 5;
 451                }
 452                scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
 453                sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
 454        } else {
 455                /* Program desired operating rate */
 456                fclk_rate /= (psc + 1) * 1000;
 457                if (psc > 2)
 458                        psc = 2;
 459                scll = fclk_rate / (omap->speed * 2) - 7 + psc;
 460                sclh = fclk_rate / (omap->speed * 2) - 7 + psc;
 461        }
 462
 463        omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
 464                        OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
 465                        OMAP_I2C_IE_AL)  | ((omap->fifo_size) ?
 466                                (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
 467
 468        omap->pscstate = psc;
 469        omap->scllstate = scll;
 470        omap->sclhstate = sclh;
 471
 472        if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) {
 473                /* Not implemented */
 474                omap->bb_valid = 1;
 475        }
 476
 477        __omap_i2c_init(omap);
 478
 479        return 0;
 480}
 481
 482/*
 483 * Try bus recovery, but only if SDA is actually low.
 484 */
 485static int omap_i2c_recover_bus(struct omap_i2c_dev *omap)
 486{
 487        u16 systest;
 488
 489        systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
 490        if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
 491            (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC))
 492                return 0; /* bus seems to already be fine */
 493        if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC))
 494                return -EBUSY; /* recovery would not fix SCL */
 495        return i2c_recover_bus(&omap->adapter);
 496}
 497
 498/*
 499 * Waiting on Bus Busy
 500 */
 501static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap)
 502{
 503        unsigned long timeout;
 504
 505        timeout = jiffies + OMAP_I2C_TIMEOUT;
 506        while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
 507                if (time_after(jiffies, timeout))
 508                        return omap_i2c_recover_bus(omap);
 509                msleep(1);
 510        }
 511
 512        return 0;
 513}
 514
 515/*
 516 * Wait while BB-bit doesn't reflect the I2C bus state
 517 *
 518 * In a multimaster environment, after IP software reset, BB-bit value doesn't
 519 * correspond to the current bus state. It may happen what BB-bit will be 0,
 520 * while the bus is busy due to another I2C master activity.
 521 * Here are BB-bit values after reset:
 522 *     SDA   SCL   BB   NOTES
 523 *       0     0    0   1, 2
 524 *       1     0    0   1, 2
 525 *       0     1    1
 526 *       1     1    0   3
 527 * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START)
 528 * combinations on the bus, it set BB-bit to 1.
 529 * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus,
 530 * it set BB-bit to 0 and BF to 1.
 531 * BB and BF bits correctly tracks the bus state while IP is suspended
 532 * BB bit became valid on the next FCLK clock after CON_EN bit set
 533 *
 534 * NOTES:
 535 * 1. Any transfer started when BB=0 and bus is busy wouldn't be
 536 *    completed by IP and results in controller timeout.
 537 * 2. Any transfer started when BB=0 and SCL=0 results in IP
 538 *    starting to drive SDA low. In that case IP corrupt data
 539 *    on the bus.
 540 * 3. Any transfer started in the middle of another master's transfer
 541 *    results in unpredictable results and data corruption
 542 */
 543static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap)
 544{
 545        unsigned long bus_free_timeout = 0;
 546        unsigned long timeout;
 547        int bus_free = 0;
 548        u16 stat, systest;
 549
 550        if (omap->bb_valid)
 551                return 0;
 552
 553        timeout = jiffies + OMAP_I2C_TIMEOUT;
 554        while (1) {
 555                stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
 556                /*
 557                 * We will see BB or BF event in a case IP had detected any
 558                 * activity on the I2C bus. Now IP correctly tracks the bus
 559                 * state. BB-bit value is valid.
 560                 */
 561                if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF))
 562                        break;
 563
 564                /*
 565                 * Otherwise, we must look signals on the bus to make
 566                 * the right decision.
 567                 */
 568                systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
 569                if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
 570                    (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) {
 571                        if (!bus_free) {
 572                                bus_free_timeout = jiffies +
 573                                        OMAP_I2C_BUS_FREE_TIMEOUT;
 574                                bus_free = 1;
 575                        }
 576
 577                        /*
 578                         * SDA and SCL lines was high for 10 ms without bus
 579                         * activity detected. The bus is free. Consider
 580                         * BB-bit value is valid.
 581                         */
 582                        if (time_after(jiffies, bus_free_timeout))
 583                                break;
 584                } else {
 585                        bus_free = 0;
 586                }
 587
 588                if (time_after(jiffies, timeout)) {
 589                        /*
 590                         * SDA or SCL were low for the entire timeout without
 591                         * any activity detected. Most likely, a slave is
 592                         * locking up the bus with no master driving the clock.
 593                         */
 594                        dev_warn(omap->dev, "timeout waiting for bus ready\n");
 595                        return omap_i2c_recover_bus(omap);
 596                }
 597
 598                msleep(1);
 599        }
 600
 601        omap->bb_valid = 1;
 602        return 0;
 603}
 604
 605static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx)
 606{
 607        u16             buf;
 608
 609        if (omap->flags & OMAP_I2C_FLAG_NO_FIFO)
 610                return;
 611
 612        /*
 613         * Set up notification threshold based on message size. We're doing
 614         * this to try and avoid draining feature as much as possible. Whenever
 615         * we have big messages to transfer (bigger than our total fifo size)
 616         * then we might use draining feature to transfer the remaining bytes.
 617         */
 618
 619        omap->threshold = clamp(size, (u8) 1, omap->fifo_size);
 620
 621        buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
 622
 623        if (is_rx) {
 624                /* Clear RX Threshold */
 625                buf &= ~(0x3f << 8);
 626                buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
 627        } else {
 628                /* Clear TX Threshold */
 629                buf &= ~0x3f;
 630                buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
 631        }
 632
 633        omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf);
 634
 635        if (omap->rev < OMAP_I2C_REV_ON_3630)
 636                omap->b_hw = 1; /* Enable hardware fixes */
 637
 638        /* calculate wakeup latency constraint for MPU */
 639        if (omap->set_mpu_wkup_lat != NULL)
 640                omap->latency = (1000000 * omap->threshold) /
 641                        (1000 * omap->speed / 8);
 642}
 643
 644static void omap_i2c_wait(struct omap_i2c_dev *omap)
 645{
 646        u16 stat;
 647        u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
 648        int count = 0;
 649
 650        do {
 651                stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
 652                count++;
 653        } while (!(stat & mask) && count < 5);
 654}
 655
 656/*
 657 * Low level master read/write transaction.
 658 */
 659static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 660                             struct i2c_msg *msg, int stop, bool polling)
 661{
 662        struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
 663        unsigned long timeout;
 664        u16 w;
 665        int ret;
 666
 667        dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
 668                msg->addr, msg->len, msg->flags, stop);
 669
 670        omap->receiver = !!(msg->flags & I2C_M_RD);
 671        omap_i2c_resize_fifo(omap, msg->len, omap->receiver);
 672
 673        omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr);
 674
 675        /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
 676        omap->buf = msg->buf;
 677        omap->buf_len = msg->len;
 678
 679        /* make sure writes to omap->buf_len are ordered */
 680        barrier();
 681
 682        omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len);
 683
 684        /* Clear the FIFO Buffers */
 685        w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
 686        w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
 687        omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);
 688
 689        if (!polling)
 690                reinit_completion(&omap->cmd_complete);
 691        omap->cmd_err = 0;
 692
 693        w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
 694
 695        /* High speed configuration */
 696        if (omap->speed > 400)
 697                w |= OMAP_I2C_CON_OPMODE_HS;
 698
 699        if (msg->flags & I2C_M_STOP)
 700                stop = 1;
 701        if (msg->flags & I2C_M_TEN)
 702                w |= OMAP_I2C_CON_XA;
 703        if (!(msg->flags & I2C_M_RD))
 704                w |= OMAP_I2C_CON_TRX;
 705
 706        if (!omap->b_hw && stop)
 707                w |= OMAP_I2C_CON_STP;
 708        /*
 709         * NOTE: STAT_BB bit could became 1 here if another master occupy
 710         * the bus. IP successfully complete transfer when the bus will be
 711         * free again (BB reset to 0).
 712         */
 713        omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
 714
 715        /*
 716         * Don't write stt and stp together on some hardware.
 717         */
 718        if (omap->b_hw && stop) {
 719                unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
 720                u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
 721                while (con & OMAP_I2C_CON_STT) {
 722                        con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
 723
 724                        /* Let the user know if i2c is in a bad state */
 725                        if (time_after(jiffies, delay)) {
 726                                dev_err(omap->dev, "controller timed out "
 727                                "waiting for start condition to finish\n");
 728                                return -ETIMEDOUT;
 729                        }
 730                        cpu_relax();
 731                }
 732
 733                w |= OMAP_I2C_CON_STP;
 734                w &= ~OMAP_I2C_CON_STT;
 735                omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
 736        }
 737
 738        /*
 739         * REVISIT: We should abort the transfer on signals, but the bus goes
 740         * into arbitration and we're currently unable to recover from it.
 741         */
 742        if (!polling) {
 743                timeout = wait_for_completion_timeout(&omap->cmd_complete,
 744                                                      OMAP_I2C_TIMEOUT);
 745        } else {
 746                do {
 747                        omap_i2c_wait(omap);
 748                        ret = omap_i2c_xfer_data(omap);
 749                } while (ret == -EAGAIN);
 750
 751                timeout = !ret;
 752        }
 753
 754        if (timeout == 0) {
 755                dev_err(omap->dev, "controller timed out\n");
 756                omap_i2c_reset(omap);
 757                __omap_i2c_init(omap);
 758                return -ETIMEDOUT;
 759        }
 760
 761        if (likely(!omap->cmd_err))
 762                return 0;
 763
 764        /* We have an error */
 765        if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) {
 766                omap_i2c_reset(omap);
 767                __omap_i2c_init(omap);
 768                return -EIO;
 769        }
 770
 771        if (omap->cmd_err & OMAP_I2C_STAT_AL)
 772                return -EAGAIN;
 773
 774        if (omap->cmd_err & OMAP_I2C_STAT_NACK) {
 775                if (msg->flags & I2C_M_IGNORE_NAK)
 776                        return 0;
 777
 778                w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
 779                w |= OMAP_I2C_CON_STP;
 780                omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
 781                return -EREMOTEIO;
 782        }
 783        return -EIO;
 784}
 785
 786
 787/*
 788 * Prepare controller for a transaction and call omap_i2c_xfer_msg
 789 * to do the work during IRQ processing.
 790 */
 791static int
 792omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num,
 793                     bool polling)
 794{
 795        struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
 796        int i;
 797        int r;
 798
 799        r = pm_runtime_get_sync(omap->dev);
 800        if (r < 0)
 801                goto out;
 802
 803        r = omap_i2c_wait_for_bb_valid(omap);
 804        if (r < 0)
 805                goto out;
 806
 807        r = omap_i2c_wait_for_bb(omap);
 808        if (r < 0)
 809                goto out;
 810
 811        if (omap->set_mpu_wkup_lat != NULL)
 812                omap->set_mpu_wkup_lat(omap->dev, omap->latency);
 813
 814        for (i = 0; i < num; i++) {
 815                r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)),
 816                                      polling);
 817                if (r != 0)
 818                        break;
 819        }
 820
 821        if (r == 0)
 822                r = num;
 823
 824        omap_i2c_wait_for_bb(omap);
 825
 826        if (omap->set_mpu_wkup_lat != NULL)
 827                omap->set_mpu_wkup_lat(omap->dev, -1);
 828
 829out:
 830        pm_runtime_mark_last_busy(omap->dev);
 831        pm_runtime_put_autosuspend(omap->dev);
 832        return r;
 833}
 834
 835static int
 836omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 837{
 838        return omap_i2c_xfer_common(adap, msgs, num, false);
 839}
 840
 841static int
 842omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 843{
 844        return omap_i2c_xfer_common(adap, msgs, num, true);
 845}
 846
 847static u32
 848omap_i2c_func(struct i2c_adapter *adap)
 849{
 850        return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
 851               I2C_FUNC_PROTOCOL_MANGLING;
 852}
 853
 854static inline void
 855omap_i2c_complete_cmd(struct omap_i2c_dev *omap, u16 err)
 856{
 857        omap->cmd_err |= err;
 858        complete(&omap->cmd_complete);
 859}
 860
 861static inline void
 862omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat)
 863{
 864        omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat);
 865}
 866
 867static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, u16 stat)
 868{
 869        /*
 870         * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
 871         * Not applicable for OMAP4.
 872         * Under certain rare conditions, RDR could be set again
 873         * when the bus is busy, then ignore the interrupt and
 874         * clear the interrupt.
 875         */
 876        if (stat & OMAP_I2C_STAT_RDR) {
 877                /* Step 1: If RDR is set, clear it */
 878                omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
 879
 880                /* Step 2: */
 881                if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
 882                                                & OMAP_I2C_STAT_BB)) {
 883
 884                        /* Step 3: */
 885                        if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
 886                                                & OMAP_I2C_STAT_RDR) {
 887                                omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
 888                                dev_dbg(omap->dev, "RDR when bus is busy.\n");
 889                        }
 890
 891                }
 892        }
 893}
 894
 895/* rev1 devices are apparently only on some 15xx */
 896#ifdef CONFIG_ARCH_OMAP15XX
 897
 898static irqreturn_t
 899omap_i2c_omap1_isr(int this_irq, void *dev_id)
 900{
 901        struct omap_i2c_dev *omap = dev_id;
 902        u16 iv, w;
 903
 904        if (pm_runtime_suspended(omap->dev))
 905                return IRQ_NONE;
 906
 907        iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG);
 908        switch (iv) {
 909        case 0x00:      /* None */
 910                break;
 911        case 0x01:      /* Arbitration lost */
 912                dev_err(omap->dev, "Arbitration lost\n");
 913                omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL);
 914                break;
 915        case 0x02:      /* No acknowledgement */
 916                omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK);
 917                omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
 918                break;
 919        case 0x03:      /* Register access ready */
 920                omap_i2c_complete_cmd(omap, 0);
 921                break;
 922        case 0x04:      /* Receive data ready */
 923                if (omap->buf_len) {
 924                        w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
 925                        *omap->buf++ = w;
 926                        omap->buf_len--;
 927                        if (omap->buf_len) {
 928                                *omap->buf++ = w >> 8;
 929                                omap->buf_len--;
 930                        }
 931                } else
 932                        dev_err(omap->dev, "RRDY IRQ while no data requested\n");
 933                break;
 934        case 0x05:      /* Transmit data ready */
 935                if (omap->buf_len) {
 936                        w = *omap->buf++;
 937                        omap->buf_len--;
 938                        if (omap->buf_len) {
 939                                w |= *omap->buf++ << 8;
 940                                omap->buf_len--;
 941                        }
 942                        omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
 943                } else
 944                        dev_err(omap->dev, "XRDY IRQ while no data to send\n");
 945                break;
 946        default:
 947                return IRQ_NONE;
 948        }
 949
 950        return IRQ_HANDLED;
 951}
 952#else
 953#define omap_i2c_omap1_isr              NULL
 954#endif
 955
 956/*
 957 * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing
 958 * data to DATA_REG. Otherwise some data bytes can be lost while transferring
 959 * them from the memory to the I2C interface.
 960 */
 961static int errata_omap3_i462(struct omap_i2c_dev *omap)
 962{
 963        unsigned long timeout = 10000;
 964        u16 stat;
 965
 966        do {
 967                stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
 968                if (stat & OMAP_I2C_STAT_XUDF)
 969                        break;
 970
 971                if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
 972                        omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_XRDY |
 973                                                        OMAP_I2C_STAT_XDR));
 974                        if (stat & OMAP_I2C_STAT_NACK) {
 975                                omap->cmd_err |= OMAP_I2C_STAT_NACK;
 976                                omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
 977                        }
 978
 979                        if (stat & OMAP_I2C_STAT_AL) {
 980                                dev_err(omap->dev, "Arbitration lost\n");
 981                                omap->cmd_err |= OMAP_I2C_STAT_AL;
 982                                omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
 983                        }
 984
 985                        return -EIO;
 986                }
 987
 988                cpu_relax();
 989        } while (--timeout);
 990
 991        if (!timeout) {
 992                dev_err(omap->dev, "timeout waiting on XUDF bit\n");
 993                return 0;
 994        }
 995
 996        return 0;
 997}
 998
 999static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes,
1000                bool is_rdr)
1001{
1002        u16             w;
1003
1004        while (num_bytes--) {
1005                w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
1006                *omap->buf++ = w;
1007                omap->buf_len--;
1008
1009                /*
1010                 * Data reg in 2430, omap3 and
1011                 * omap4 is 8 bit wide
1012                 */
1013                if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
1014                        *omap->buf++ = w >> 8;
1015                        omap->buf_len--;
1016                }
1017        }
1018}
1019
1020static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes,
1021                bool is_xdr)
1022{
1023        u16             w;
1024
1025        while (num_bytes--) {
1026                w = *omap->buf++;
1027                omap->buf_len--;
1028
1029                /*
1030                 * Data reg in 2430, omap3 and
1031                 * omap4 is 8 bit wide
1032                 */
1033                if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
1034                        w |= *omap->buf++ << 8;
1035                        omap->buf_len--;
1036                }
1037
1038                if (omap->errata & I2C_OMAP_ERRATA_I462) {
1039                        int ret;
1040
1041                        ret = errata_omap3_i462(omap);
1042                        if (ret < 0)
1043                                return ret;
1044                }
1045
1046                omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
1047        }
1048
1049        return 0;
1050}
1051
1052static irqreturn_t
1053omap_i2c_isr(int irq, void *dev_id)
1054{
1055        struct omap_i2c_dev *omap = dev_id;
1056        irqreturn_t ret = IRQ_HANDLED;
1057        u16 mask;
1058        u16 stat;
1059
1060        stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
1061        mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
1062
1063        if (stat & mask)
1064                ret = IRQ_WAKE_THREAD;
1065
1066        return ret;
1067}
1068
1069static int omap_i2c_xfer_data(struct omap_i2c_dev *omap)
1070{
1071        u16 bits;
1072        u16 stat;
1073        int err = 0, count = 0;
1074
1075        do {
1076                bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
1077                stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
1078                stat &= bits;
1079
1080                /* If we're in receiver mode, ignore XDR/XRDY */
1081                if (omap->receiver)
1082                        stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
1083                else
1084                        stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
1085
1086                if (!stat) {
1087                        /* my work here is done */
1088                        err = -EAGAIN;
1089                        break;
1090                }
1091
1092                dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat);
1093                if (count++ == 100) {
1094                        dev_warn(omap->dev, "Too much work in one IRQ\n");
1095                        break;
1096                }
1097
1098                if (stat & OMAP_I2C_STAT_NACK) {
1099                        err |= OMAP_I2C_STAT_NACK;
1100                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
1101                }
1102
1103                if (stat & OMAP_I2C_STAT_AL) {
1104                        dev_err(omap->dev, "Arbitration lost\n");
1105                        err |= OMAP_I2C_STAT_AL;
1106                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
1107                }
1108
1109                /*
1110                 * ProDB0017052: Clear ARDY bit twice
1111                 */
1112                if (stat & OMAP_I2C_STAT_ARDY)
1113                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY);
1114
1115                if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
1116                                        OMAP_I2C_STAT_AL)) {
1117                        omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_RRDY |
1118                                                OMAP_I2C_STAT_RDR |
1119                                                OMAP_I2C_STAT_XRDY |
1120                                                OMAP_I2C_STAT_XDR |
1121                                                OMAP_I2C_STAT_ARDY));
1122                        break;
1123                }
1124
1125                if (stat & OMAP_I2C_STAT_RDR) {
1126                        u8 num_bytes = 1;
1127
1128                        if (omap->fifo_size)
1129                                num_bytes = omap->buf_len;
1130
1131                        if (omap->errata & I2C_OMAP_ERRATA_I207) {
1132                                i2c_omap_errata_i207(omap, stat);
1133                                num_bytes = (omap_i2c_read_reg(omap,
1134                                        OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F;
1135                        }
1136
1137                        omap_i2c_receive_data(omap, num_bytes, true);
1138                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
1139                        continue;
1140                }
1141
1142                if (stat & OMAP_I2C_STAT_RRDY) {
1143                        u8 num_bytes = 1;
1144
1145                        if (omap->threshold)
1146                                num_bytes = omap->threshold;
1147
1148                        omap_i2c_receive_data(omap, num_bytes, false);
1149                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY);
1150                        continue;
1151                }
1152
1153                if (stat & OMAP_I2C_STAT_XDR) {
1154                        u8 num_bytes = 1;
1155                        int ret;
1156
1157                        if (omap->fifo_size)
1158                                num_bytes = omap->buf_len;
1159
1160                        ret = omap_i2c_transmit_data(omap, num_bytes, true);
1161                        if (ret < 0)
1162                                break;
1163
1164                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR);
1165                        continue;
1166                }
1167
1168                if (stat & OMAP_I2C_STAT_XRDY) {
1169                        u8 num_bytes = 1;
1170                        int ret;
1171
1172                        if (omap->threshold)
1173                                num_bytes = omap->threshold;
1174
1175                        ret = omap_i2c_transmit_data(omap, num_bytes, false);
1176                        if (ret < 0)
1177                                break;
1178
1179                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY);
1180                        continue;
1181                }
1182
1183                if (stat & OMAP_I2C_STAT_ROVR) {
1184                        dev_err(omap->dev, "Receive overrun\n");
1185                        err |= OMAP_I2C_STAT_ROVR;
1186                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR);
1187                        break;
1188                }
1189
1190                if (stat & OMAP_I2C_STAT_XUDF) {
1191                        dev_err(omap->dev, "Transmit underflow\n");
1192                        err |= OMAP_I2C_STAT_XUDF;
1193                        omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF);
1194                        break;
1195                }
1196        } while (stat);
1197
1198        return err;
1199}
1200
1201static irqreturn_t
1202omap_i2c_isr_thread(int this_irq, void *dev_id)
1203{
1204        int ret;
1205        struct omap_i2c_dev *omap = dev_id;
1206
1207        ret = omap_i2c_xfer_data(omap);
1208        if (ret != -EAGAIN)
1209                omap_i2c_complete_cmd(omap, ret);
1210
1211        return IRQ_HANDLED;
1212}
1213
1214static const struct i2c_algorithm omap_i2c_algo = {
1215        .master_xfer    = omap_i2c_xfer_irq,
1216        .master_xfer_atomic     = omap_i2c_xfer_polling,
1217        .functionality  = omap_i2c_func,
1218};
1219
1220static const struct i2c_adapter_quirks omap_i2c_quirks = {
1221        .flags = I2C_AQ_NO_ZERO_LEN,
1222};
1223
1224#ifdef CONFIG_OF
1225static struct omap_i2c_bus_platform_data omap2420_pdata = {
1226        .rev = OMAP_I2C_IP_VERSION_1,
1227        .flags = OMAP_I2C_FLAG_NO_FIFO |
1228                        OMAP_I2C_FLAG_SIMPLE_CLOCK |
1229                        OMAP_I2C_FLAG_16BIT_DATA_REG |
1230                        OMAP_I2C_FLAG_BUS_SHIFT_2,
1231};
1232
1233static struct omap_i2c_bus_platform_data omap2430_pdata = {
1234        .rev = OMAP_I2C_IP_VERSION_1,
1235        .flags = OMAP_I2C_FLAG_BUS_SHIFT_2 |
1236                        OMAP_I2C_FLAG_FORCE_19200_INT_CLK,
1237};
1238
1239static struct omap_i2c_bus_platform_data omap3_pdata = {
1240        .rev = OMAP_I2C_IP_VERSION_1,
1241        .flags = OMAP_I2C_FLAG_BUS_SHIFT_2,
1242};
1243
1244static struct omap_i2c_bus_platform_data omap4_pdata = {
1245        .rev = OMAP_I2C_IP_VERSION_2,
1246};
1247
1248static const struct of_device_id omap_i2c_of_match[] = {
1249        {
1250                .compatible = "ti,omap4-i2c",
1251                .data = &omap4_pdata,
1252        },
1253        {
1254                .compatible = "ti,omap3-i2c",
1255                .data = &omap3_pdata,
1256        },
1257        {
1258                .compatible = "ti,omap2430-i2c",
1259                .data = &omap2430_pdata,
1260        },
1261        {
1262                .compatible = "ti,omap2420-i2c",
1263                .data = &omap2420_pdata,
1264        },
1265        { },
1266};
1267MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
1268#endif
1269
1270#define OMAP_I2C_SCHEME(rev)            ((rev & 0xc000) >> 14)
1271
1272#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)
1273#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)
1274
1275#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)
1276#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)
1277#define OMAP_I2C_SCHEME_0               0
1278#define OMAP_I2C_SCHEME_1               1
1279
1280static int omap_i2c_get_scl(struct i2c_adapter *adap)
1281{
1282        struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1283        u32 reg;
1284
1285        reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1286
1287        return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
1288}
1289
1290static int omap_i2c_get_sda(struct i2c_adapter *adap)
1291{
1292        struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1293        u32 reg;
1294
1295        reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1296
1297        return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
1298}
1299
1300static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)
1301{
1302        struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1303        u32 reg;
1304
1305        reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1306        if (val)
1307                reg |= OMAP_I2C_SYSTEST_SCL_O;
1308        else
1309                reg &= ~OMAP_I2C_SYSTEST_SCL_O;
1310        omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
1311}
1312
1313static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)
1314{
1315        struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1316        u32 reg;
1317
1318        reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1319        /* enable test mode */
1320        reg |= OMAP_I2C_SYSTEST_ST_EN;
1321        /* select SDA/SCL IO mode */
1322        reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT;
1323        /* set SCL to high-impedance state (reset value is 0) */
1324        reg |= OMAP_I2C_SYSTEST_SCL_O;
1325        /* set SDA to high-impedance state (reset value is 0) */
1326        reg |= OMAP_I2C_SYSTEST_SDA_O;
1327        omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
1328}
1329
1330static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)
1331{
1332        struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
1333        u32 reg;
1334
1335        reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
1336        /* restore reset values */
1337        reg &= ~OMAP_I2C_SYSTEST_ST_EN;
1338        reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK;
1339        reg &= ~OMAP_I2C_SYSTEST_SCL_O;
1340        reg &= ~OMAP_I2C_SYSTEST_SDA_O;
1341        omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
1342}
1343
1344static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
1345        .get_scl                = omap_i2c_get_scl,
1346        .get_sda                = omap_i2c_get_sda,
1347        .set_scl                = omap_i2c_set_scl,
1348        .prepare_recovery       = omap_i2c_prepare_recovery,
1349        .unprepare_recovery     = omap_i2c_unprepare_recovery,
1350        .recover_bus            = i2c_generic_scl_recovery,
1351};
1352
1353static int
1354omap_i2c_probe(struct platform_device *pdev)
1355{
1356        struct omap_i2c_dev     *omap;
1357        struct i2c_adapter      *adap;
1358        const struct omap_i2c_bus_platform_data *pdata =
1359                dev_get_platdata(&pdev->dev);
1360        struct device_node      *node = pdev->dev.of_node;
1361        const struct of_device_id *match;
1362        int irq;
1363        int r;
1364        u32 rev;
1365        u16 minor, major;
1366
1367        irq = platform_get_irq(pdev, 0);
1368        if (irq < 0)
1369                return irq;
1370
1371        omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
1372        if (!omap)
1373                return -ENOMEM;
1374
1375        omap->base = devm_platform_ioremap_resource(pdev, 0);
1376        if (IS_ERR(omap->base))
1377                return PTR_ERR(omap->base);
1378
1379        match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
1380        if (match) {
1381                u32 freq = I2C_MAX_STANDARD_MODE_FREQ;
1382
1383                pdata = match->data;
1384                omap->flags = pdata->flags;
1385
1386                of_property_read_u32(node, "clock-frequency", &freq);
1387                /* convert DT freq value in Hz into kHz for speed */
1388                omap->speed = freq / 1000;
1389        } else if (pdata != NULL) {
1390                omap->speed = pdata->clkrate;
1391                omap->flags = pdata->flags;
1392                omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
1393        }
1394
1395        omap->dev = &pdev->dev;
1396        omap->irq = irq;
1397
1398        platform_set_drvdata(pdev, omap);
1399        init_completion(&omap->cmd_complete);
1400
1401        omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
1402
1403        pm_runtime_enable(omap->dev);
1404        pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
1405        pm_runtime_use_autosuspend(omap->dev);
1406
1407        r = pm_runtime_get_sync(omap->dev);
1408        if (r < 0)
1409                goto err_free_mem;
1410
1411        /*
1412         * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
1413         * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.
1414         * Also since the omap_i2c_read_reg uses reg_map_ip_* a
1415         * readw_relaxed is done.
1416         */
1417        rev = readw_relaxed(omap->base + 0x04);
1418
1419        omap->scheme = OMAP_I2C_SCHEME(rev);
1420        switch (omap->scheme) {
1421        case OMAP_I2C_SCHEME_0:
1422                omap->regs = (u8 *)reg_map_ip_v1;
1423                omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG);
1424                minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
1425                major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
1426                break;
1427        case OMAP_I2C_SCHEME_1:
1428                /* FALLTHROUGH */
1429        default:
1430                omap->regs = (u8 *)reg_map_ip_v2;
1431                rev = (rev << 16) |
1432                        omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO);
1433                minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);
1434                major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);
1435                omap->rev = rev;
1436        }
1437
1438        omap->errata = 0;
1439
1440        if (omap->rev >= OMAP_I2C_REV_ON_2430 &&
1441                        omap->rev < OMAP_I2C_REV_ON_4430_PLUS)
1442                omap->errata |= I2C_OMAP_ERRATA_I207;
1443
1444        if (omap->rev <= OMAP_I2C_REV_ON_3430_3530)
1445                omap->errata |= I2C_OMAP_ERRATA_I462;
1446
1447        if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) {
1448                u16 s;
1449
1450                /* Set up the fifo size - Get total size */
1451                s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1452                omap->fifo_size = 0x8 << s;
1453
1454                /*
1455                 * Set up notification threshold as half the total available
1456                 * size. This is to ensure that we can handle the status on int
1457                 * call back latencies.
1458                 */
1459
1460                omap->fifo_size = (omap->fifo_size / 2);
1461
1462                if (omap->rev < OMAP_I2C_REV_ON_3630)
1463                        omap->b_hw = 1; /* Enable hardware fixes */
1464
1465                /* calculate wakeup latency constraint for MPU */
1466                if (omap->set_mpu_wkup_lat != NULL)
1467                        omap->latency = (1000000 * omap->fifo_size) /
1468                                       (1000 * omap->speed / 8);
1469        }
1470
1471        /* reset ASAP, clearing any IRQs */
1472        omap_i2c_init(omap);
1473
1474        if (omap->rev < OMAP_I2C_OMAP1_REV_2)
1475                r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr,
1476                                IRQF_NO_SUSPEND, pdev->name, omap);
1477        else
1478                r = devm_request_threaded_irq(&pdev->dev, omap->irq,
1479                                omap_i2c_isr, omap_i2c_isr_thread,
1480                                IRQF_NO_SUSPEND | IRQF_ONESHOT,
1481                                pdev->name, omap);
1482
1483        if (r) {
1484                dev_err(omap->dev, "failure requesting irq %i\n", omap->irq);
1485                goto err_unuse_clocks;
1486        }
1487
1488        adap = &omap->adapter;
1489        i2c_set_adapdata(adap, omap);
1490        adap->owner = THIS_MODULE;
1491        adap->class = I2C_CLASS_DEPRECATED;
1492        strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1493        adap->algo = &omap_i2c_algo;
1494        adap->quirks = &omap_i2c_quirks;
1495        adap->dev.parent = &pdev->dev;
1496        adap->dev.of_node = pdev->dev.of_node;
1497        adap->bus_recovery_info = &omap_i2c_bus_recovery_info;
1498
1499        /* i2c device drivers may be active on return from add_adapter() */
1500        adap->nr = pdev->id;
1501        r = i2c_add_numbered_adapter(adap);
1502        if (r)
1503                goto err_unuse_clocks;
1504
1505        dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr,
1506                 major, minor, omap->speed);
1507
1508        pm_runtime_mark_last_busy(omap->dev);
1509        pm_runtime_put_autosuspend(omap->dev);
1510
1511        return 0;
1512
1513err_unuse_clocks:
1514        omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
1515        pm_runtime_dont_use_autosuspend(omap->dev);
1516        pm_runtime_put_sync(omap->dev);
1517        pm_runtime_disable(&pdev->dev);
1518err_free_mem:
1519
1520        return r;
1521}
1522
1523static int omap_i2c_remove(struct platform_device *pdev)
1524{
1525        struct omap_i2c_dev     *omap = platform_get_drvdata(pdev);
1526        int ret;
1527
1528        i2c_del_adapter(&omap->adapter);
1529        ret = pm_runtime_get_sync(&pdev->dev);
1530        if (ret < 0)
1531                return ret;
1532
1533        omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
1534        pm_runtime_dont_use_autosuspend(&pdev->dev);
1535        pm_runtime_put_sync(&pdev->dev);
1536        pm_runtime_disable(&pdev->dev);
1537        return 0;
1538}
1539
1540static int __maybe_unused omap_i2c_runtime_suspend(struct device *dev)
1541{
1542        struct omap_i2c_dev *omap = dev_get_drvdata(dev);
1543
1544        omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
1545
1546        if (omap->scheme == OMAP_I2C_SCHEME_0)
1547                omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0);
1548        else
1549                omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR,
1550                                   OMAP_I2C_IP_V2_INTERRUPTS_MASK);
1551
1552        if (omap->rev < OMAP_I2C_OMAP1_REV_2) {
1553                omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */
1554        } else {
1555                omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate);
1556
1557                /* Flush posted write */
1558                omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
1559        }
1560
1561        pinctrl_pm_select_sleep_state(dev);
1562
1563        return 0;
1564}
1565
1566static int __maybe_unused omap_i2c_runtime_resume(struct device *dev)
1567{
1568        struct omap_i2c_dev *omap = dev_get_drvdata(dev);
1569
1570        pinctrl_pm_select_default_state(dev);
1571
1572        if (!omap->regs)
1573                return 0;
1574
1575        __omap_i2c_init(omap);
1576
1577        return 0;
1578}
1579
1580static const struct dev_pm_ops omap_i2c_pm_ops = {
1581        SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1582                                      pm_runtime_force_resume)
1583        SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
1584                           omap_i2c_runtime_resume, NULL)
1585};
1586
1587static struct platform_driver omap_i2c_driver = {
1588        .probe          = omap_i2c_probe,
1589        .remove         = omap_i2c_remove,
1590        .driver         = {
1591                .name   = "omap_i2c",
1592                .pm     = &omap_i2c_pm_ops,
1593                .of_match_table = of_match_ptr(omap_i2c_of_match),
1594        },
1595};
1596
1597/* I2C may be needed to bring up other drivers */
1598static int __init
1599omap_i2c_init_driver(void)
1600{
1601        return platform_driver_register(&omap_i2c_driver);
1602}
1603subsys_initcall(omap_i2c_init_driver);
1604
1605static void __exit omap_i2c_exit_driver(void)
1606{
1607        platform_driver_unregister(&omap_i2c_driver);
1608}
1609module_exit(omap_i2c_exit_driver);
1610
1611MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1612MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1613MODULE_LICENSE("GPL");
1614MODULE_ALIAS("platform:omap_i2c");
1615