drivers/i2c/busses/i2c-mpc.c

   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
  59 struct 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
  72 struct mpc_i2c_divider {
  73         u16 divider;
  74         u16 fdr;        /* including dfsrr */
  75 };
  76
  77 struct mpc_i2c_data {
  78         void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
  79                       u32 clock, u32 prescaler);
  80         u32 prescaler;
  81 };
  82
  83 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
  84 {
  85         writeb(x, i2c->base + MPC_I2C_CR);
  86 }
  87
  88 static 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  */
 105 static 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
 122 static 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)
 178 static 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
 199 static 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
 233 static 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) */
 255 static 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
 263 static 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 */
 291 static 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
 299 static 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
 319 static 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
 348 static 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
 386 static 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 */
 411 static 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
 418 static 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
 426 static void mpc_i2c_stop(struct mpc_i2c *i2c)
 427 {
 428         writeccr(i2c, CCR_MEN);
 429 }
 430
 431 static 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
 459 static 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
 530 static 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
 599 static 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
 605 static const struct i2c_algorithm mpc_algo = {
 606         .master_xfer = mpc_xfer,
 607         .functionality = mpc_functionality,
 608 };
 609
 610 static struct i2c_adapter mpc_ops = {
 611         .owner = THIS_MODULE,
 612         .name = "MPC adapter",
 613         .algo = &mpc_algo,
 614         .timeout = HZ,
 615 };
 616
 617 static const struct of_device_id mpc_i2c_of_match[];
 618 static 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         dev_set_drvdata(&op->dev, 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
 708 static int fsl_i2c_remove(struct platform_device *op)
 709 {
 710         struct mpc_i2c *i2c = dev_get_drvdata(&op->dev);
 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
 724 static 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
 734 static 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
 744 SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
 745 #endif
 746
 747 static const struct mpc_i2c_data mpc_i2c_data_512x = {
 748         .setup = mpc_i2c_setup_512x,
 749 };
 750
 751 static const struct mpc_i2c_data mpc_i2c_data_52xx = {
 752         .setup = mpc_i2c_setup_52xx,
 753 };
 754
 755 static const struct mpc_i2c_data mpc_i2c_data_8313 = {
 756         .setup = mpc_i2c_setup_8xxx,
 757 };
 758
 759 static const struct mpc_i2c_data mpc_i2c_data_8543 = {
 760         .setup = mpc_i2c_setup_8xxx,
 761         .prescaler = 2,
 762 };
 763
 764 static const struct mpc_i2c_data mpc_i2c_data_8544 = {
 765         .setup = mpc_i2c_setup_8xxx,
 766         .prescaler = 3,
 767 };
 768
 769 static 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 };
 781 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
 782
 783 /* Structure for a device driver */
 784 static 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
 797 module_platform_driver(mpc_i2c_driver);
 798
 799 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 800 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
 801                    "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 802 MODULE_LICENSE("GPL");