linux/drivers/i2c/busses/i2c-mpc.c
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   1/*
   2 * (C) Copyright 2003-2004
   3 * Humboldt Solutions Ltd, adrian@humboldt.co.uk.
   4
   5 * This is a combined i2c adapter and algorithm driver for the
   6 * MPC107/Tsi107 PowerPC northbridge and processors that include
   7 * the same I2C unit (8240, 8245, 85xx).
   8 *
   9 * Release 0.8
  10 *
  11 * This file is licensed under the terms of the GNU General Public
  12 * License version 2. This program is licensed "as is" without any
  13 * warranty of any kind, whether express or implied.
  14 */
  15
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/sched.h>
  19#include <linux/init.h>
  20#include <linux/of_platform.h>
  21#include <linux/of_i2c.h>
  22#include <linux/slab.h>
  23
  24#include <linux/io.h>
  25#include <linux/fsl_devices.h>
  26#include <linux/i2c.h>
  27#include <linux/interrupt.h>
  28#include <linux/delay.h>
  29
  30#include <asm/mpc52xx.h>
  31#include <sysdev/fsl_soc.h>
  32
  33#define DRV_NAME "mpc-i2c"
  34
  35#define MPC_I2C_CLOCK_LEGACY   0
  36#define MPC_I2C_CLOCK_PRESERVE (~0U)
  37
  38#define MPC_I2C_FDR   0x04
  39#define MPC_I2C_CR    0x08
  40#define MPC_I2C_SR    0x0c
  41#define MPC_I2C_DR    0x10
  42#define MPC_I2C_DFSRR 0x14
  43
  44#define CCR_MEN  0x80
  45#define CCR_MIEN 0x40
  46#define CCR_MSTA 0x20
  47#define CCR_MTX  0x10
  48#define CCR_TXAK 0x08
  49#define CCR_RSTA 0x04
  50
  51#define CSR_MCF  0x80
  52#define CSR_MAAS 0x40
  53#define CSR_MBB  0x20
  54#define CSR_MAL  0x10
  55#define CSR_SRW  0x04
  56#define CSR_MIF  0x02
  57#define CSR_RXAK 0x01
  58
  59struct mpc_i2c {
  60        struct device *dev;
  61        void __iomem *base;
  62        u32 interrupt;
  63        wait_queue_head_t queue;
  64        struct i2c_adapter adap;
  65        int irq;
  66        u32 real_clk;
  67#ifdef CONFIG_PM
  68        u8 fdr, dfsrr;
  69#endif
  70};
  71
  72struct mpc_i2c_divider {
  73        u16 divider;
  74        u16 fdr;        /* including dfsrr */
  75};
  76
  77struct mpc_i2c_data {
  78        void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
  79                      u32 clock, u32 prescaler);
  80        u32 prescaler;
  81};
  82
  83static inline void writeccr(struct mpc_i2c *i2c, u32 x)
  84{
  85        writeb(x, i2c->base + MPC_I2C_CR);
  86}
  87
  88static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
  89{
  90        struct mpc_i2c *i2c = dev_id;
  91        if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
  92                /* Read again to allow register to stabilise */
  93                i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
  94                writeb(0, i2c->base + MPC_I2C_SR);
  95                wake_up(&i2c->queue);
  96        }
  97        return IRQ_HANDLED;
  98}
  99
 100/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
 101 * the bus, because it wants to send ACK.
 102 * Following sequence of enabling/disabling and sending start/stop generates
 103 * the 9 pulses, so it's all OK.
 104 */
 105static void mpc_i2c_fixup(struct mpc_i2c *i2c)
 106{
 107        int k;
 108        u32 delay_val = 1000000 / i2c->real_clk + 1;
 109
 110        if (delay_val < 2)
 111                delay_val = 2;
 112
 113        for (k = 9; k; k--) {
 114                writeccr(i2c, 0);
 115                writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
 116                udelay(delay_val);
 117                writeccr(i2c, CCR_MEN);
 118                udelay(delay_val << 1);
 119        }
 120}
 121
 122static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 123{
 124        unsigned long orig_jiffies = jiffies;
 125        u32 x;
 126        int result = 0;
 127
 128        if (!i2c->irq) {
 129                while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
 130                        schedule();
 131                        if (time_after(jiffies, orig_jiffies + timeout)) {
 132                                dev_dbg(i2c->dev, "timeout\n");
 133                                writeccr(i2c, 0);
 134                                result = -EIO;
 135                                break;
 136                        }
 137                }
 138                x = readb(i2c->base + MPC_I2C_SR);
 139                writeb(0, i2c->base + MPC_I2C_SR);
 140        } else {
 141                /* Interrupt mode */
 142                result = wait_event_timeout(i2c->queue,
 143                        (i2c->interrupt & CSR_MIF), timeout);
 144
 145                if (unlikely(!(i2c->interrupt & CSR_MIF))) {
 146                        dev_dbg(i2c->dev, "wait timeout\n");
 147                        writeccr(i2c, 0);
 148                        result = -ETIMEDOUT;
 149                }
 150
 151                x = i2c->interrupt;
 152                i2c->interrupt = 0;
 153        }
 154
 155        if (result < 0)
 156                return result;
 157
 158        if (!(x & CSR_MCF)) {
 159                dev_dbg(i2c->dev, "unfinished\n");
 160                return -EIO;
 161        }
 162
 163        if (x & CSR_MAL) {
 164                dev_dbg(i2c->dev, "MAL\n");
 165                return -EIO;
 166        }
 167
 168        if (writing && (x & CSR_RXAK)) {
 169                dev_dbg(i2c->dev, "No RXAK\n");
 170                /* generate stop */
 171                writeccr(i2c, CCR_MEN);
 172                return -EIO;
 173        }
 174        return 0;
 175}
 176
 177#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
 178static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
 179        {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
 180        {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
 181        {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
 182        {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
 183        {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
 184        {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
 185        {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
 186        {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
 187        {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
 188        {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
 189        {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
 190        {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
 191        {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
 192        {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
 193        {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
 194        {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
 195        {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
 196        {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
 197};
 198
 199static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
 200                                          int prescaler, u32 *real_clk)
 201{
 202        const struct mpc_i2c_divider *div = NULL;
 203        unsigned int pvr = mfspr(SPRN_PVR);
 204        u32 divider;
 205        int i;
 206
 207        if (clock == MPC_I2C_CLOCK_LEGACY) {
 208                /* see below - default fdr = 0x3f -> div = 2048 */
 209                *real_clk = mpc5xxx_get_bus_frequency(node) / 2048;
 210                return -EINVAL;
 211        }
 212
 213        /* Determine divider value */
 214        divider = mpc5xxx_get_bus_frequency(node) / clock;
 215
 216        /*
 217         * We want to choose an FDR/DFSR that generates an I2C bus speed that
 218         * is equal to or lower than the requested speed.
 219         */
 220        for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
 221                div = &mpc_i2c_dividers_52xx[i];
 222                /* Old MPC5200 rev A CPUs do not support the high bits */
 223                if (div->fdr & 0xc0 && pvr == 0x80822011)
 224                        continue;
 225                if (div->divider >= divider)
 226                        break;
 227        }
 228
 229        *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider;
 230        return (int)div->fdr;
 231}
 232
 233static void mpc_i2c_setup_52xx(struct device_node *node,
 234                                         struct mpc_i2c *i2c,
 235                                         u32 clock, u32 prescaler)
 236{
 237        int ret, fdr;
 238
 239        if (clock == MPC_I2C_CLOCK_PRESERVE) {
 240                dev_dbg(i2c->dev, "using fdr %d\n",
 241                        readb(i2c->base + MPC_I2C_FDR));
 242                return;
 243        }
 244
 245        ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk);
 246        fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
 247
 248        writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 249
 250        if (ret >= 0)
 251                dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
 252                         fdr);
 253}
 254#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
 255static void mpc_i2c_setup_52xx(struct device_node *node,
 256                                         struct mpc_i2c *i2c,
 257                                         u32 clock, u32 prescaler)
 258{
 259}
 260#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
 261
 262#ifdef CONFIG_PPC_MPC512x
 263static void mpc_i2c_setup_512x(struct device_node *node,
 264                                         struct mpc_i2c *i2c,
 265                                         u32 clock, u32 prescaler)
 266{
 267        struct device_node *node_ctrl;
 268        void __iomem *ctrl;
 269        const u32 *pval;
 270        u32 idx;
 271
 272        /* Enable I2C interrupts for mpc5121 */
 273        node_ctrl = of_find_compatible_node(NULL, NULL,
 274                                            "fsl,mpc5121-i2c-ctrl");
 275        if (node_ctrl) {
 276                ctrl = of_iomap(node_ctrl, 0);
 277                if (ctrl) {
 278                        /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
 279                        pval = of_get_property(node, "reg", NULL);
 280                        idx = (*pval & 0xff) / 0x20;
 281                        setbits32(ctrl, 1 << (24 + idx * 2));
 282                        iounmap(ctrl);
 283                }
 284                of_node_put(node_ctrl);
 285        }
 286
 287        /* The clock setup for the 52xx works also fine for the 512x */
 288        mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
 289}
 290#else /* CONFIG_PPC_MPC512x */
 291static void mpc_i2c_setup_512x(struct device_node *node,
 292                                         struct mpc_i2c *i2c,
 293                                         u32 clock, u32 prescaler)
 294{
 295}
 296#endif /* CONFIG_PPC_MPC512x */
 297
 298#ifdef CONFIG_FSL_SOC
 299static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
 300        {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
 301        {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
 302        {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
 303        {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
 304        {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
 305        {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
 306        {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
 307        {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
 308        {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
 309        {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
 310        {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
 311        {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
 312        {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
 313        {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
 314        {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
 315        {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
 316        {49152, 0x011e}, {61440, 0x011f}
 317};
 318
 319static u32 mpc_i2c_get_sec_cfg_8xxx(void)
 320{
 321        struct device_node *node = NULL;
 322        u32 __iomem *reg;
 323        u32 val = 0;
 324
 325        node = of_find_node_by_name(NULL, "global-utilities");
 326        if (node) {
 327                const u32 *prop = of_get_property(node, "reg", NULL);
 328                if (prop) {
 329                        /*
 330                         * Map and check POR Device Status Register 2
 331                         * (PORDEVSR2) at 0xE0014
 332                         */
 333                        reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
 334                        if (!reg)
 335                                printk(KERN_ERR
 336                                       "Error: couldn't map PORDEVSR2\n");
 337                        else
 338                                val = in_be32(reg) & 0x00000080; /* sec-cfg */
 339                        iounmap(reg);
 340                }
 341        }
 342        if (node)
 343                of_node_put(node);
 344
 345        return val;
 346}
 347
 348static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
 349                                          u32 prescaler, u32 *real_clk)
 350{
 351        const struct mpc_i2c_divider *div = NULL;
 352        u32 divider;
 353        int i;
 354
 355        if (clock == MPC_I2C_CLOCK_LEGACY) {
 356                /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
 357                *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
 358                return -EINVAL;
 359        }
 360
 361        /* Determine proper divider value */
 362        if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
 363                prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
 364        if (!prescaler)
 365                prescaler = 1;
 366
 367        divider = fsl_get_sys_freq() / clock / prescaler;
 368
 369        pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
 370                 fsl_get_sys_freq(), clock, divider);
 371
 372        /*
 373         * We want to choose an FDR/DFSR that generates an I2C bus speed that
 374         * is equal to or lower than the requested speed.
 375         */
 376        for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
 377                div = &mpc_i2c_dividers_8xxx[i];
 378                if (div->divider >= divider)
 379                        break;
 380        }
 381
 382        *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
 383        return div ? (int)div->fdr : -EINVAL;
 384}
 385
 386static void mpc_i2c_setup_8xxx(struct device_node *node,
 387                                         struct mpc_i2c *i2c,
 388                                         u32 clock, u32 prescaler)
 389{
 390        int ret, fdr;
 391
 392        if (clock == MPC_I2C_CLOCK_PRESERVE) {
 393                dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
 394                        readb(i2c->base + MPC_I2C_DFSRR),
 395                        readb(i2c->base + MPC_I2C_FDR));
 396                return;
 397        }
 398
 399        ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
 400        fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
 401
 402        writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 403        writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
 404
 405        if (ret >= 0)
 406                dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
 407                         i2c->real_clk, fdr >> 8, fdr & 0xff);
 408}
 409
 410#else /* !CONFIG_FSL_SOC */
 411static void mpc_i2c_setup_8xxx(struct device_node *node,
 412                                         struct mpc_i2c *i2c,
 413                                         u32 clock, u32 prescaler)
 414{
 415}
 416#endif /* CONFIG_FSL_SOC */
 417
 418static void mpc_i2c_start(struct mpc_i2c *i2c)
 419{
 420        /* Clear arbitration */
 421        writeb(0, i2c->base + MPC_I2C_SR);
 422        /* Start with MEN */
 423        writeccr(i2c, CCR_MEN);
 424}
 425
 426static void mpc_i2c_stop(struct mpc_i2c *i2c)
 427{
 428        writeccr(i2c, CCR_MEN);
 429}
 430
 431static int mpc_write(struct mpc_i2c *i2c, int target,
 432                     const u8 *data, int length, int restart)
 433{
 434        int i, result;
 435        unsigned timeout = i2c->adap.timeout;
 436        u32 flags = restart ? CCR_RSTA : 0;
 437
 438        /* Start as master */
 439        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 440        /* Write target byte */
 441        writeb((target << 1), i2c->base + MPC_I2C_DR);
 442
 443        result = i2c_wait(i2c, timeout, 1);
 444        if (result < 0)
 445                return result;
 446
 447        for (i = 0; i < length; i++) {
 448                /* Write data byte */
 449                writeb(data[i], i2c->base + MPC_I2C_DR);
 450
 451                result = i2c_wait(i2c, timeout, 1);
 452                if (result < 0)
 453                        return result;
 454        }
 455
 456        return 0;
 457}
 458
 459static int mpc_read(struct mpc_i2c *i2c, int target,
 460                    u8 *data, int length, int restart, bool recv_len)
 461{
 462        unsigned timeout = i2c->adap.timeout;
 463        int i, result;
 464        u32 flags = restart ? CCR_RSTA : 0;
 465
 466        /* Switch to read - restart */
 467        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 468        /* Write target address byte - this time with the read flag set */
 469        writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
 470
 471        result = i2c_wait(i2c, timeout, 1);
 472        if (result < 0)
 473                return result;
 474
 475        if (length) {
 476                if (length == 1 && !recv_len)
 477                        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 478                else
 479                        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
 480                /* Dummy read */
 481                readb(i2c->base + MPC_I2C_DR);
 482        }
 483
 484        for (i = 0; i < length; i++) {
 485                u8 byte;
 486
 487                result = i2c_wait(i2c, timeout, 0);
 488                if (result < 0)
 489                        return result;
 490
 491                /*
 492                 * For block reads, we have to know the total length (1st byte)
 493                 * before we can determine if we are done.
 494                 */
 495                if (i || !recv_len) {
 496                        /* Generate txack on next to last byte */
 497                        if (i == length - 2)
 498                                writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 499                                         | CCR_TXAK);
 500                        /* Do not generate stop on last byte */
 501                        if (i == length - 1)
 502                                writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 503                                         | CCR_MTX);
 504                }
 505
 506                byte = readb(i2c->base + MPC_I2C_DR);
 507
 508                /*
 509                 * Adjust length if first received byte is length.
 510                 * The length is 1 length byte plus actually data length
 511                 */
 512                if (i == 0 && recv_len) {
 513                        if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
 514                                return -EPROTO;
 515                        length += byte;
 516                        /*
 517                         * For block reads, generate txack here if data length
 518                         * is 1 byte (total length is 2 bytes).
 519                         */
 520                        if (length == 2)
 521                                writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 522                                         | CCR_TXAK);
 523                }
 524                data[i] = byte;
 525        }
 526
 527        return length;
 528}
 529
 530static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 531{
 532        struct i2c_msg *pmsg;
 533        int i;
 534        int ret = 0;
 535        unsigned long orig_jiffies = jiffies;
 536        struct mpc_i2c *i2c = i2c_get_adapdata(adap);
 537
 538        mpc_i2c_start(i2c);
 539
 540        /* Allow bus up to 1s to become not busy */
 541        while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 542                if (signal_pending(current)) {
 543                        dev_dbg(i2c->dev, "Interrupted\n");
 544                        writeccr(i2c, 0);
 545                        return -EINTR;
 546                }
 547                if (time_after(jiffies, orig_jiffies + HZ)) {
 548                        u8 status = readb(i2c->base + MPC_I2C_SR);
 549
 550                        dev_dbg(i2c->dev, "timeout\n");
 551                        if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 552                                writeb(status & ~CSR_MAL,
 553                                       i2c->base + MPC_I2C_SR);
 554                                mpc_i2c_fixup(i2c);
 555                        }
 556                        return -EIO;
 557                }
 558                schedule();
 559        }
 560
 561        for (i = 0; ret >= 0 && i < num; i++) {
 562                pmsg = &msgs[i];
 563                dev_dbg(i2c->dev,
 564                        "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 565                        pmsg->flags & I2C_M_RD ? "read" : "write",
 566                        pmsg->len, pmsg->addr, i + 1, num);
 567                if (pmsg->flags & I2C_M_RD) {
 568                        bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
 569
 570                        ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
 571                                       recv_len);
 572                        if (recv_len && ret > 0)
 573                                pmsg->len = ret;
 574                } else {
 575                        ret =
 576                            mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
 577                }
 578        }
 579        mpc_i2c_stop(i2c); /* Initiate STOP */
 580        orig_jiffies = jiffies;
 581        /* Wait until STOP is seen, allow up to 1 s */
 582        while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 583                if (time_after(jiffies, orig_jiffies + HZ)) {
 584                        u8 status = readb(i2c->base + MPC_I2C_SR);
 585
 586                        dev_dbg(i2c->dev, "timeout\n");
 587                        if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 588                                writeb(status & ~CSR_MAL,
 589                                       i2c->base + MPC_I2C_SR);
 590                                mpc_i2c_fixup(i2c);
 591                        }
 592                        return -EIO;
 593                }
 594                cond_resched();
 595        }
 596        return (ret < 0) ? ret : num;
 597}
 598
 599static u32 mpc_functionality(struct i2c_adapter *adap)
 600{
 601        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
 602          | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 603}
 604
 605static const struct i2c_algorithm mpc_algo = {
 606        .master_xfer = mpc_xfer,
 607        .functionality = mpc_functionality,
 608};
 609
 610static struct i2c_adapter mpc_ops = {
 611        .owner = THIS_MODULE,
 612        .name = "MPC adapter",
 613        .algo = &mpc_algo,
 614        .timeout = HZ,
 615};
 616
 617static const struct of_device_id mpc_i2c_of_match[];
 618static int fsl_i2c_probe(struct platform_device *op)
 619{
 620        const struct of_device_id *match;
 621        struct mpc_i2c *i2c;
 622        const u32 *prop;
 623        u32 clock = MPC_I2C_CLOCK_LEGACY;
 624        int result = 0;
 625        int plen;
 626
 627        match = of_match_device(mpc_i2c_of_match, &op->dev);
 628        if (!match)
 629                return -EINVAL;
 630
 631        i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
 632        if (!i2c)
 633                return -ENOMEM;
 634
 635        i2c->dev = &op->dev; /* for debug and error output */
 636
 637        init_waitqueue_head(&i2c->queue);
 638
 639        i2c->base = of_iomap(op->dev.of_node, 0);
 640        if (!i2c->base) {
 641                dev_err(i2c->dev, "failed to map controller\n");
 642                result = -ENOMEM;
 643                goto fail_map;
 644        }
 645
 646        i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
 647        if (i2c->irq) { /* no i2c->irq implies polling */
 648                result = request_irq(i2c->irq, mpc_i2c_isr,
 649                                     IRQF_SHARED, "i2c-mpc", i2c);
 650                if (result < 0) {
 651                        dev_err(i2c->dev, "failed to attach interrupt\n");
 652                        goto fail_request;
 653                }
 654        }
 655
 656        if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) {
 657                clock = MPC_I2C_CLOCK_PRESERVE;
 658        } else {
 659                prop = of_get_property(op->dev.of_node, "clock-frequency",
 660                                        &plen);
 661                if (prop && plen == sizeof(u32))
 662                        clock = *prop;
 663        }
 664
 665        if (match->data) {
 666                const struct mpc_i2c_data *data = match->data;
 667                data->setup(op->dev.of_node, i2c, clock, data->prescaler);
 668        } else {
 669                /* Backwards compatibility */
 670                if (of_get_property(op->dev.of_node, "dfsrr", NULL))
 671                        mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
 672        }
 673
 674        prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
 675        if (prop && plen == sizeof(u32)) {
 676                mpc_ops.timeout = *prop * HZ / 1000000;
 677                if (mpc_ops.timeout < 5)
 678                        mpc_ops.timeout = 5;
 679        }
 680        dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
 681
 682        platform_set_drvdata(op, i2c);
 683
 684        i2c->adap = mpc_ops;
 685        i2c_set_adapdata(&i2c->adap, i2c);
 686        i2c->adap.dev.parent = &op->dev;
 687        i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
 688
 689        result = i2c_add_adapter(&i2c->adap);
 690        if (result < 0) {
 691                dev_err(i2c->dev, "failed to add adapter\n");
 692                goto fail_add;
 693        }
 694        of_i2c_register_devices(&i2c->adap);
 695
 696        return result;
 697
 698 fail_add:
 699        free_irq(i2c->irq, i2c);
 700 fail_request:
 701        irq_dispose_mapping(i2c->irq);
 702        iounmap(i2c->base);
 703 fail_map:
 704        kfree(i2c);
 705        return result;
 706};
 707
 708static int fsl_i2c_remove(struct platform_device *op)
 709{
 710        struct mpc_i2c *i2c = platform_get_drvdata(op);
 711
 712        i2c_del_adapter(&i2c->adap);
 713
 714        if (i2c->irq)
 715                free_irq(i2c->irq, i2c);
 716
 717        irq_dispose_mapping(i2c->irq);
 718        iounmap(i2c->base);
 719        kfree(i2c);
 720        return 0;
 721};
 722
 723#ifdef CONFIG_PM
 724static int mpc_i2c_suspend(struct device *dev)
 725{
 726        struct mpc_i2c *i2c = dev_get_drvdata(dev);
 727
 728        i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
 729        i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
 730
 731        return 0;
 732}
 733
 734static int mpc_i2c_resume(struct device *dev)
 735{
 736        struct mpc_i2c *i2c = dev_get_drvdata(dev);
 737
 738        writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
 739        writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
 740
 741        return 0;
 742}
 743
 744SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
 745#endif
 746
 747static const struct mpc_i2c_data mpc_i2c_data_512x = {
 748        .setup = mpc_i2c_setup_512x,
 749};
 750
 751static const struct mpc_i2c_data mpc_i2c_data_52xx = {
 752        .setup = mpc_i2c_setup_52xx,
 753};
 754
 755static const struct mpc_i2c_data mpc_i2c_data_8313 = {
 756        .setup = mpc_i2c_setup_8xxx,
 757};
 758
 759static const struct mpc_i2c_data mpc_i2c_data_8543 = {
 760        .setup = mpc_i2c_setup_8xxx,
 761        .prescaler = 2,
 762};
 763
 764static const struct mpc_i2c_data mpc_i2c_data_8544 = {
 765        .setup = mpc_i2c_setup_8xxx,
 766        .prescaler = 3,
 767};
 768
 769static const struct of_device_id mpc_i2c_of_match[] = {
 770        {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 771        {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
 772        {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 773        {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
 774        {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
 775        {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
 776        {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
 777        /* Backward compatibility */
 778        {.compatible = "fsl-i2c", },
 779        {},
 780};
 781MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
 782
 783/* Structure for a device driver */
 784static struct platform_driver mpc_i2c_driver = {
 785        .probe          = fsl_i2c_probe,
 786        .remove         = fsl_i2c_remove,
 787        .driver = {
 788                .owner = THIS_MODULE,
 789                .name = DRV_NAME,
 790                .of_match_table = mpc_i2c_of_match,
 791#ifdef CONFIG_PM
 792                .pm = &mpc_i2c_pm_ops,
 793#endif
 794        },
 795};
 796
 797module_platform_driver(mpc_i2c_driver);
 798
 799MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 800MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
 801                   "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 802MODULE_LICENSE("GPL");
 803