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/signal.h>
  19#include <linux/of_address.h>
  20#include <linux/of_irq.h>
  21#include <linux/of_platform.h>
  22#include <linux/slab.h>
  23
  24#include <linux/clk.h>
  25#include <linux/io.h>
  26#include <linux/fsl_devices.h>
  27#include <linux/i2c.h>
  28#include <linux/interrupt.h>
  29#include <linux/delay.h>
  30
  31#include <asm/mpc52xx.h>
  32#include <asm/mpc85xx.h>
  33#include <sysdev/fsl_soc.h>
  34
  35#define DRV_NAME "mpc-i2c"
  36
  37#define MPC_I2C_CLOCK_LEGACY   0
  38#define MPC_I2C_CLOCK_PRESERVE (~0U)
  39
  40#define MPC_I2C_FDR   0x04
  41#define MPC_I2C_CR    0x08
  42#define MPC_I2C_SR    0x0c
  43#define MPC_I2C_DR    0x10
  44#define MPC_I2C_DFSRR 0x14
  45
  46#define CCR_MEN  0x80
  47#define CCR_MIEN 0x40
  48#define CCR_MSTA 0x20
  49#define CCR_MTX  0x10
  50#define CCR_TXAK 0x08
  51#define CCR_RSTA 0x04
  52
  53#define CSR_MCF  0x80
  54#define CSR_MAAS 0x40
  55#define CSR_MBB  0x20
  56#define CSR_MAL  0x10
  57#define CSR_SRW  0x04
  58#define CSR_MIF  0x02
  59#define CSR_RXAK 0x01
  60
  61struct mpc_i2c {
  62        struct device *dev;
  63        void __iomem *base;
  64        u32 interrupt;
  65        wait_queue_head_t queue;
  66        struct i2c_adapter adap;
  67        int irq;
  68        u32 real_clk;
  69#ifdef CONFIG_PM_SLEEP
  70        u8 fdr, dfsrr;
  71#endif
  72        struct clk *clk_per;
  73};
  74
  75struct mpc_i2c_divider {
  76        u16 divider;
  77        u16 fdr;        /* including dfsrr */
  78};
  79
  80struct mpc_i2c_data {
  81        void (*setup)(struct device_node *node, struct mpc_i2c *i2c, u32 clock);
  82};
  83
  84static inline void writeccr(struct mpc_i2c *i2c, u32 x)
  85{
  86        writeb(x, i2c->base + MPC_I2C_CR);
  87}
  88
  89static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
  90{
  91        struct mpc_i2c *i2c = dev_id;
  92        if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
  93                /* Read again to allow register to stabilise */
  94                i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
  95                writeb(0, i2c->base + MPC_I2C_SR);
  96                wake_up(&i2c->queue);
  97                return IRQ_HANDLED;
  98        }
  99        return IRQ_NONE;
 100}
 101
 102/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
 103 * the bus, because it wants to send ACK.
 104 * Following sequence of enabling/disabling and sending start/stop generates
 105 * the 9 pulses, so it's all OK.
 106 */
 107static void mpc_i2c_fixup(struct mpc_i2c *i2c)
 108{
 109        int k;
 110        u32 delay_val = 1000000 / i2c->real_clk + 1;
 111
 112        if (delay_val < 2)
 113                delay_val = 2;
 114
 115        for (k = 9; k; k--) {
 116                writeccr(i2c, 0);
 117                writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
 118                readb(i2c->base + MPC_I2C_DR);
 119                writeccr(i2c, CCR_MEN);
 120                udelay(delay_val << 1);
 121        }
 122}
 123
 124static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 125{
 126        unsigned long orig_jiffies = jiffies;
 127        u32 cmd_err;
 128        int result = 0;
 129
 130        if (!i2c->irq) {
 131                while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
 132                        schedule();
 133                        if (time_after(jiffies, orig_jiffies + timeout)) {
 134                                dev_dbg(i2c->dev, "timeout\n");
 135                                writeccr(i2c, 0);
 136                                result = -ETIMEDOUT;
 137                                break;
 138                        }
 139                }
 140                cmd_err = readb(i2c->base + MPC_I2C_SR);
 141                writeb(0, i2c->base + MPC_I2C_SR);
 142        } else {
 143                /* Interrupt mode */
 144                result = wait_event_timeout(i2c->queue,
 145                        (i2c->interrupt & CSR_MIF), timeout);
 146
 147                if (unlikely(!(i2c->interrupt & CSR_MIF))) {
 148                        dev_dbg(i2c->dev, "wait timeout\n");
 149                        writeccr(i2c, 0);
 150                        result = -ETIMEDOUT;
 151                }
 152
 153                cmd_err = i2c->interrupt;
 154                i2c->interrupt = 0;
 155        }
 156
 157        if (result < 0)
 158                return result;
 159
 160        if (!(cmd_err & CSR_MCF)) {
 161                dev_dbg(i2c->dev, "unfinished\n");
 162                return -EIO;
 163        }
 164
 165        if (cmd_err & CSR_MAL) {
 166                dev_dbg(i2c->dev, "MAL\n");
 167                return -EAGAIN;
 168        }
 169
 170        if (writing && (cmd_err & CSR_RXAK)) {
 171                dev_dbg(i2c->dev, "No RXAK\n");
 172                /* generate stop */
 173                writeccr(i2c, CCR_MEN);
 174                return -ENXIO;
 175        }
 176        return 0;
 177}
 178
 179#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
 180static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
 181        {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
 182        {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
 183        {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
 184        {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
 185        {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
 186        {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
 187        {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
 188        {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
 189        {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
 190        {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
 191        {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
 192        {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
 193        {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
 194        {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
 195        {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
 196        {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
 197        {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
 198        {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
 199};
 200
 201static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
 202                                          u32 *real_clk)
 203{
 204        const struct mpc_i2c_divider *div = NULL;
 205        unsigned int pvr = mfspr(SPRN_PVR);
 206        u32 divider;
 207        int i;
 208
 209        if (clock == MPC_I2C_CLOCK_LEGACY) {
 210                /* see below - default fdr = 0x3f -> div = 2048 */
 211                *real_clk = mpc5xxx_get_bus_frequency(node) / 2048;
 212                return -EINVAL;
 213        }
 214
 215        /* Determine divider value */
 216        divider = mpc5xxx_get_bus_frequency(node) / clock;
 217
 218        /*
 219         * We want to choose an FDR/DFSR that generates an I2C bus speed that
 220         * is equal to or lower than the requested speed.
 221         */
 222        for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
 223                div = &mpc_i2c_dividers_52xx[i];
 224                /* Old MPC5200 rev A CPUs do not support the high bits */
 225                if (div->fdr & 0xc0 && pvr == 0x80822011)
 226                        continue;
 227                if (div->divider >= divider)
 228                        break;
 229        }
 230
 231        *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider;
 232        return (int)div->fdr;
 233}
 234
 235static void mpc_i2c_setup_52xx(struct device_node *node,
 236                                         struct mpc_i2c *i2c,
 237                                         u32 clock)
 238{
 239        int ret, fdr;
 240
 241        if (clock == MPC_I2C_CLOCK_PRESERVE) {
 242                dev_dbg(i2c->dev, "using fdr %d\n",
 243                        readb(i2c->base + MPC_I2C_FDR));
 244                return;
 245        }
 246
 247        ret = mpc_i2c_get_fdr_52xx(node, clock, &i2c->real_clk);
 248        fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
 249
 250        writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 251
 252        if (ret >= 0)
 253                dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
 254                         fdr);
 255}
 256#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
 257static void mpc_i2c_setup_52xx(struct device_node *node,
 258                                         struct mpc_i2c *i2c,
 259                                         u32 clock)
 260{
 261}
 262#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
 263
 264#ifdef CONFIG_PPC_MPC512x
 265static void mpc_i2c_setup_512x(struct device_node *node,
 266                                         struct mpc_i2c *i2c,
 267                                         u32 clock)
 268{
 269        struct device_node *node_ctrl;
 270        void __iomem *ctrl;
 271        const u32 *pval;
 272        u32 idx;
 273
 274        /* Enable I2C interrupts for mpc5121 */
 275        node_ctrl = of_find_compatible_node(NULL, NULL,
 276                                            "fsl,mpc5121-i2c-ctrl");
 277        if (node_ctrl) {
 278                ctrl = of_iomap(node_ctrl, 0);
 279                if (ctrl) {
 280                        /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
 281                        pval = of_get_property(node, "reg", NULL);
 282                        idx = (*pval & 0xff) / 0x20;
 283                        setbits32(ctrl, 1 << (24 + idx * 2));
 284                        iounmap(ctrl);
 285                }
 286                of_node_put(node_ctrl);
 287        }
 288
 289        /* The clock setup for the 52xx works also fine for the 512x */
 290        mpc_i2c_setup_52xx(node, i2c, clock);
 291}
 292#else /* CONFIG_PPC_MPC512x */
 293static void mpc_i2c_setup_512x(struct device_node *node,
 294                                         struct mpc_i2c *i2c,
 295                                         u32 clock)
 296{
 297}
 298#endif /* CONFIG_PPC_MPC512x */
 299
 300#ifdef CONFIG_FSL_SOC
 301static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
 302        {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
 303        {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
 304        {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
 305        {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
 306        {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
 307        {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
 308        {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
 309        {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
 310        {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
 311        {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
 312        {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
 313        {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
 314        {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
 315        {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
 316        {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
 317        {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
 318        {49152, 0x011e}, {61440, 0x011f}
 319};
 320
 321static u32 mpc_i2c_get_sec_cfg_8xxx(void)
 322{
 323        struct device_node *node;
 324        u32 __iomem *reg;
 325        u32 val = 0;
 326
 327        node = of_find_node_by_name(NULL, "global-utilities");
 328        if (node) {
 329                const u32 *prop = of_get_property(node, "reg", NULL);
 330                if (prop) {
 331                        /*
 332                         * Map and check POR Device Status Register 2
 333                         * (PORDEVSR2) at 0xE0014. Note than while MPC8533
 334                         * and MPC8544 indicate SEC frequency ratio
 335                         * configuration as bit 26 in PORDEVSR2, other MPC8xxx
 336                         * parts may store it differently or may not have it
 337                         * at all.
 338                         */
 339                        reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
 340                        if (!reg)
 341                                printk(KERN_ERR
 342                                       "Error: couldn't map PORDEVSR2\n");
 343                        else
 344                                val = in_be32(reg) & 0x00000020; /* sec-cfg */
 345                        iounmap(reg);
 346                }
 347        }
 348        of_node_put(node);
 349
 350        return val;
 351}
 352
 353static u32 mpc_i2c_get_prescaler_8xxx(void)
 354{
 355        /*
 356         * According to the AN2919 all MPC824x have prescaler 1, while MPC83xx
 357         * may have prescaler 1, 2, or 3, depending on the power-on
 358         * configuration.
 359         */
 360        u32 prescaler = 1;
 361
 362        /* mpc85xx */
 363        if (pvr_version_is(PVR_VER_E500V1) || pvr_version_is(PVR_VER_E500V2)
 364                || pvr_version_is(PVR_VER_E500MC)
 365                || pvr_version_is(PVR_VER_E5500)
 366                || pvr_version_is(PVR_VER_E6500)) {
 367                unsigned int svr = mfspr(SPRN_SVR);
 368
 369                if ((SVR_SOC_VER(svr) == SVR_8540)
 370                        || (SVR_SOC_VER(svr) == SVR_8541)
 371                        || (SVR_SOC_VER(svr) == SVR_8560)
 372                        || (SVR_SOC_VER(svr) == SVR_8555)
 373                        || (SVR_SOC_VER(svr) == SVR_8610))
 374                        /* the above 85xx SoCs have prescaler 1 */
 375                        prescaler = 1;
 376                else if ((SVR_SOC_VER(svr) == SVR_8533)
 377                        || (SVR_SOC_VER(svr) == SVR_8544))
 378                        /* the above 85xx SoCs have prescaler 3 or 2 */
 379                        prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
 380                else
 381                        /* all the other 85xx have prescaler 2 */
 382                        prescaler = 2;
 383        }
 384
 385        return prescaler;
 386}
 387
 388static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
 389                                          u32 *real_clk)
 390{
 391        const struct mpc_i2c_divider *div = NULL;
 392        u32 prescaler = mpc_i2c_get_prescaler_8xxx();
 393        u32 divider;
 394        int i;
 395
 396        if (clock == MPC_I2C_CLOCK_LEGACY) {
 397                /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
 398                *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
 399                return -EINVAL;
 400        }
 401
 402        divider = fsl_get_sys_freq() / clock / prescaler;
 403
 404        pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
 405                 fsl_get_sys_freq(), clock, divider);
 406
 407        /*
 408         * We want to choose an FDR/DFSR that generates an I2C bus speed that
 409         * is equal to or lower than the requested speed.
 410         */
 411        for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
 412                div = &mpc_i2c_dividers_8xxx[i];
 413                if (div->divider >= divider)
 414                        break;
 415        }
 416
 417        *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
 418        return div ? (int)div->fdr : -EINVAL;
 419}
 420
 421static void mpc_i2c_setup_8xxx(struct device_node *node,
 422                                         struct mpc_i2c *i2c,
 423                                         u32 clock)
 424{
 425        int ret, fdr;
 426
 427        if (clock == MPC_I2C_CLOCK_PRESERVE) {
 428                dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
 429                        readb(i2c->base + MPC_I2C_DFSRR),
 430                        readb(i2c->base + MPC_I2C_FDR));
 431                return;
 432        }
 433
 434        ret = mpc_i2c_get_fdr_8xxx(node, clock, &i2c->real_clk);
 435        fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
 436
 437        writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 438        writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
 439
 440        if (ret >= 0)
 441                dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
 442                         i2c->real_clk, fdr >> 8, fdr & 0xff);
 443}
 444
 445#else /* !CONFIG_FSL_SOC */
 446static void mpc_i2c_setup_8xxx(struct device_node *node,
 447                                         struct mpc_i2c *i2c,
 448                                         u32 clock)
 449{
 450}
 451#endif /* CONFIG_FSL_SOC */
 452
 453static void mpc_i2c_start(struct mpc_i2c *i2c)
 454{
 455        /* Clear arbitration */
 456        writeb(0, i2c->base + MPC_I2C_SR);
 457        /* Start with MEN */
 458        writeccr(i2c, CCR_MEN);
 459}
 460
 461static void mpc_i2c_stop(struct mpc_i2c *i2c)
 462{
 463        writeccr(i2c, CCR_MEN);
 464}
 465
 466static int mpc_write(struct mpc_i2c *i2c, int target,
 467                     const u8 *data, int length, int restart)
 468{
 469        int i, result;
 470        unsigned timeout = i2c->adap.timeout;
 471        u32 flags = restart ? CCR_RSTA : 0;
 472
 473        /* Start as master */
 474        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 475        /* Write target byte */
 476        writeb((target << 1), i2c->base + MPC_I2C_DR);
 477
 478        result = i2c_wait(i2c, timeout, 1);
 479        if (result < 0)
 480                return result;
 481
 482        for (i = 0; i < length; i++) {
 483                /* Write data byte */
 484                writeb(data[i], i2c->base + MPC_I2C_DR);
 485
 486                result = i2c_wait(i2c, timeout, 1);
 487                if (result < 0)
 488                        return result;
 489        }
 490
 491        return 0;
 492}
 493
 494static int mpc_read(struct mpc_i2c *i2c, int target,
 495                    u8 *data, int length, int restart, bool recv_len)
 496{
 497        unsigned timeout = i2c->adap.timeout;
 498        int i, result;
 499        u32 flags = restart ? CCR_RSTA : 0;
 500
 501        /* Switch to read - restart */
 502        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 503        /* Write target address byte - this time with the read flag set */
 504        writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
 505
 506        result = i2c_wait(i2c, timeout, 1);
 507        if (result < 0)
 508                return result;
 509
 510        if (length) {
 511                if (length == 1 && !recv_len)
 512                        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 513                else
 514                        writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
 515                /* Dummy read */
 516                readb(i2c->base + MPC_I2C_DR);
 517        }
 518
 519        for (i = 0; i < length; i++) {
 520                u8 byte;
 521
 522                result = i2c_wait(i2c, timeout, 0);
 523                if (result < 0)
 524                        return result;
 525
 526                /*
 527                 * For block reads, we have to know the total length (1st byte)
 528                 * before we can determine if we are done.
 529                 */
 530                if (i || !recv_len) {
 531                        /* Generate txack on next to last byte */
 532                        if (i == length - 2)
 533                                writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 534                                         | CCR_TXAK);
 535                        /* Do not generate stop on last byte */
 536                        if (i == length - 1)
 537                                writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 538                                         | CCR_MTX);
 539                }
 540
 541                byte = readb(i2c->base + MPC_I2C_DR);
 542
 543                /*
 544                 * Adjust length if first received byte is length.
 545                 * The length is 1 length byte plus actually data length
 546                 */
 547                if (i == 0 && recv_len) {
 548                        if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
 549                                return -EPROTO;
 550                        length += byte;
 551                        /*
 552                         * For block reads, generate txack here if data length
 553                         * is 1 byte (total length is 2 bytes).
 554                         */
 555                        if (length == 2)
 556                                writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 557                                         | CCR_TXAK);
 558                }
 559                data[i] = byte;
 560        }
 561
 562        return length;
 563}
 564
 565static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 566{
 567        struct i2c_msg *pmsg;
 568        int i;
 569        int ret = 0;
 570        unsigned long orig_jiffies = jiffies;
 571        struct mpc_i2c *i2c = i2c_get_adapdata(adap);
 572
 573        mpc_i2c_start(i2c);
 574
 575        /* Allow bus up to 1s to become not busy */
 576        while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 577                if (signal_pending(current)) {
 578                        dev_dbg(i2c->dev, "Interrupted\n");
 579                        writeccr(i2c, 0);
 580                        return -EINTR;
 581                }
 582                if (time_after(jiffies, orig_jiffies + HZ)) {
 583                        u8 status = readb(i2c->base + MPC_I2C_SR);
 584
 585                        dev_dbg(i2c->dev, "timeout\n");
 586                        if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 587                                writeb(status & ~CSR_MAL,
 588                                       i2c->base + MPC_I2C_SR);
 589                                mpc_i2c_fixup(i2c);
 590                        }
 591                        return -EIO;
 592                }
 593                schedule();
 594        }
 595
 596        for (i = 0; ret >= 0 && i < num; i++) {
 597                pmsg = &msgs[i];
 598                dev_dbg(i2c->dev,
 599                        "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 600                        pmsg->flags & I2C_M_RD ? "read" : "write",
 601                        pmsg->len, pmsg->addr, i + 1, num);
 602                if (pmsg->flags & I2C_M_RD) {
 603                        bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
 604
 605                        ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
 606                                       recv_len);
 607                        if (recv_len && ret > 0)
 608                                pmsg->len = ret;
 609                } else {
 610                        ret =
 611                            mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
 612                }
 613        }
 614        mpc_i2c_stop(i2c); /* Initiate STOP */
 615        orig_jiffies = jiffies;
 616        /* Wait until STOP is seen, allow up to 1 s */
 617        while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 618                if (time_after(jiffies, orig_jiffies + HZ)) {
 619                        u8 status = readb(i2c->base + MPC_I2C_SR);
 620
 621                        dev_dbg(i2c->dev, "timeout\n");
 622                        if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 623                                writeb(status & ~CSR_MAL,
 624                                       i2c->base + MPC_I2C_SR);
 625                                mpc_i2c_fixup(i2c);
 626                        }
 627                        return -EIO;
 628                }
 629                cond_resched();
 630        }
 631        return (ret < 0) ? ret : num;
 632}
 633
 634static u32 mpc_functionality(struct i2c_adapter *adap)
 635{
 636        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
 637          | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 638}
 639
 640static const struct i2c_algorithm mpc_algo = {
 641        .master_xfer = mpc_xfer,
 642        .functionality = mpc_functionality,
 643};
 644
 645static struct i2c_adapter mpc_ops = {
 646        .owner = THIS_MODULE,
 647        .algo = &mpc_algo,
 648        .timeout = HZ,
 649};
 650
 651static const struct of_device_id mpc_i2c_of_match[];
 652static int fsl_i2c_probe(struct platform_device *op)
 653{
 654        const struct of_device_id *match;
 655        struct mpc_i2c *i2c;
 656        const u32 *prop;
 657        u32 clock = MPC_I2C_CLOCK_LEGACY;
 658        int result = 0;
 659        int plen;
 660        struct resource res;
 661        struct clk *clk;
 662        int err;
 663
 664        match = of_match_device(mpc_i2c_of_match, &op->dev);
 665        if (!match)
 666                return -EINVAL;
 667
 668        i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
 669        if (!i2c)
 670                return -ENOMEM;
 671
 672        i2c->dev = &op->dev; /* for debug and error output */
 673
 674        init_waitqueue_head(&i2c->queue);
 675
 676        i2c->base = of_iomap(op->dev.of_node, 0);
 677        if (!i2c->base) {
 678                dev_err(i2c->dev, "failed to map controller\n");
 679                result = -ENOMEM;
 680                goto fail_map;
 681        }
 682
 683        i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
 684        if (i2c->irq) { /* no i2c->irq implies polling */
 685                result = request_irq(i2c->irq, mpc_i2c_isr,
 686                                     IRQF_SHARED, "i2c-mpc", i2c);
 687                if (result < 0) {
 688                        dev_err(i2c->dev, "failed to attach interrupt\n");
 689                        goto fail_request;
 690                }
 691        }
 692
 693        /*
 694         * enable clock for the I2C peripheral (non fatal),
 695         * keep a reference upon successful allocation
 696         */
 697        clk = devm_clk_get(&op->dev, NULL);
 698        if (!IS_ERR(clk)) {
 699                err = clk_prepare_enable(clk);
 700                if (err) {
 701                        dev_err(&op->dev, "failed to enable clock\n");
 702                        goto fail_request;
 703                } else {
 704                        i2c->clk_per = clk;
 705                }
 706        }
 707
 708        if (of_property_read_bool(op->dev.of_node, "fsl,preserve-clocking")) {
 709                clock = MPC_I2C_CLOCK_PRESERVE;
 710        } else {
 711                prop = of_get_property(op->dev.of_node, "clock-frequency",
 712                                        &plen);
 713                if (prop && plen == sizeof(u32))
 714                        clock = *prop;
 715        }
 716
 717        if (match->data) {
 718                const struct mpc_i2c_data *data = match->data;
 719                data->setup(op->dev.of_node, i2c, clock);
 720        } else {
 721                /* Backwards compatibility */
 722                if (of_get_property(op->dev.of_node, "dfsrr", NULL))
 723                        mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock);
 724        }
 725
 726        prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
 727        if (prop && plen == sizeof(u32)) {
 728                mpc_ops.timeout = *prop * HZ / 1000000;
 729                if (mpc_ops.timeout < 5)
 730                        mpc_ops.timeout = 5;
 731        }
 732        dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
 733
 734        platform_set_drvdata(op, i2c);
 735
 736        i2c->adap = mpc_ops;
 737        of_address_to_resource(op->dev.of_node, 0, &res);
 738        scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
 739                  "MPC adapter at 0x%llx", (unsigned long long)res.start);
 740        i2c_set_adapdata(&i2c->adap, i2c);
 741        i2c->adap.dev.parent = &op->dev;
 742        i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
 743
 744        result = i2c_add_adapter(&i2c->adap);
 745        if (result < 0)
 746                goto fail_add;
 747
 748        return result;
 749
 750 fail_add:
 751        if (i2c->clk_per)
 752                clk_disable_unprepare(i2c->clk_per);
 753        free_irq(i2c->irq, i2c);
 754 fail_request:
 755        irq_dispose_mapping(i2c->irq);
 756        iounmap(i2c->base);
 757 fail_map:
 758        kfree(i2c);
 759        return result;
 760};
 761
 762static int fsl_i2c_remove(struct platform_device *op)
 763{
 764        struct mpc_i2c *i2c = platform_get_drvdata(op);
 765
 766        i2c_del_adapter(&i2c->adap);
 767
 768        if (i2c->clk_per)
 769                clk_disable_unprepare(i2c->clk_per);
 770
 771        if (i2c->irq)
 772                free_irq(i2c->irq, i2c);
 773
 774        irq_dispose_mapping(i2c->irq);
 775        iounmap(i2c->base);
 776        kfree(i2c);
 777        return 0;
 778};
 779
 780#ifdef CONFIG_PM_SLEEP
 781static int mpc_i2c_suspend(struct device *dev)
 782{
 783        struct mpc_i2c *i2c = dev_get_drvdata(dev);
 784
 785        i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
 786        i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
 787
 788        return 0;
 789}
 790
 791static int mpc_i2c_resume(struct device *dev)
 792{
 793        struct mpc_i2c *i2c = dev_get_drvdata(dev);
 794
 795        writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
 796        writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
 797
 798        return 0;
 799}
 800
 801static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
 802#define MPC_I2C_PM_OPS  (&mpc_i2c_pm_ops)
 803#else
 804#define MPC_I2C_PM_OPS  NULL
 805#endif
 806
 807static const struct mpc_i2c_data mpc_i2c_data_512x = {
 808        .setup = mpc_i2c_setup_512x,
 809};
 810
 811static const struct mpc_i2c_data mpc_i2c_data_52xx = {
 812        .setup = mpc_i2c_setup_52xx,
 813};
 814
 815static const struct mpc_i2c_data mpc_i2c_data_8313 = {
 816        .setup = mpc_i2c_setup_8xxx,
 817};
 818
 819static const struct mpc_i2c_data mpc_i2c_data_8543 = {
 820        .setup = mpc_i2c_setup_8xxx,
 821};
 822
 823static const struct mpc_i2c_data mpc_i2c_data_8544 = {
 824        .setup = mpc_i2c_setup_8xxx,
 825};
 826
 827static const struct of_device_id mpc_i2c_of_match[] = {
 828        {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 829        {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
 830        {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 831        {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
 832        {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
 833        {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
 834        {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
 835        /* Backward compatibility */
 836        {.compatible = "fsl-i2c", },
 837        {},
 838};
 839MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
 840
 841/* Structure for a device driver */
 842static struct platform_driver mpc_i2c_driver = {
 843        .probe          = fsl_i2c_probe,
 844        .remove         = fsl_i2c_remove,
 845        .driver = {
 846                .name = DRV_NAME,
 847                .of_match_table = mpc_i2c_of_match,
 848                .pm = MPC_I2C_PM_OPS,
 849        },
 850};
 851
 852module_platform_driver(mpc_i2c_driver);
 853
 854MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 855MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
 856                   "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 857MODULE_LICENSE("GPL");
 858