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/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 <sysdev/fsl_soc.h>
  33
  34 #define DRV_NAME "mpc-i2c"
  35
  36 #define MPC_I2C_CLOCK_LEGACY   0
  37 #define MPC_I2C_CLOCK_PRESERVE (~0U)
  38
  39 #define MPC_I2C_FDR   0x04
  40 #define MPC_I2C_CR    0x08
  41 #define MPC_I2C_SR    0x0c
  42 #define MPC_I2C_DR    0x10
  43 #define MPC_I2C_DFSRR 0x14
  44
  45 #define CCR_MEN  0x80
  46 #define CCR_MIEN 0x40
  47 #define CCR_MSTA 0x20
  48 #define CCR_MTX  0x10
  49 #define CCR_TXAK 0x08
  50 #define CCR_RSTA 0x04
  51
  52 #define CSR_MCF  0x80
  53 #define CSR_MAAS 0x40
  54 #define CSR_MBB  0x20
  55 #define CSR_MAL  0x10
  56 #define CSR_SRW  0x04
  57 #define CSR_MIF  0x02
  58 #define CSR_RXAK 0x01
  59
  60 struct mpc_i2c {
  61         struct device *dev;
  62         void __iomem *base;
  63         u32 interrupt;
  64         wait_queue_head_t queue;
  65         struct i2c_adapter adap;
  66         int irq;
  67         u32 real_clk;
  68 #ifdef CONFIG_PM_SLEEP
  69         u8 fdr, dfsrr;
  70 #endif
  71         struct clk *clk_per;
  72 };
  73
  74 struct mpc_i2c_divider {
  75         u16 divider;
  76         u16 fdr;        /* including dfsrr */
  77 };
  78
  79 struct mpc_i2c_data {
  80         void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
  81                       u32 clock, u32 prescaler);
  82         u32 prescaler;
  83 };
  84
  85 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
  86 {
  87         writeb(x, i2c->base + MPC_I2C_CR);
  88 }
  89
  90 static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
  91 {
  92         struct mpc_i2c *i2c = dev_id;
  93         if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
  94                 /* Read again to allow register to stabilise */
  95                 i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
  96                 writeb(0, i2c->base + MPC_I2C_SR);
  97                 wake_up(&i2c->queue);
  98         }
  99         return IRQ_HANDLED;
 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  */
 107 static 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
 124 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 125 {
 126         unsigned long orig_jiffies = jiffies;
 127         u32 x;
 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 = -EIO;
 137                                 break;
 138                         }
 139                 }
 140                 x = 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                 x = i2c->interrupt;
 154                 i2c->interrupt = 0;
 155         }
 156
 157         if (result < 0)
 158                 return result;
 159
 160         if (!(x & CSR_MCF)) {
 161                 dev_dbg(i2c->dev, "unfinished\n");
 162                 return -EIO;
 163         }
 164
 165         if (x & CSR_MAL) {
 166                 dev_dbg(i2c->dev, "MAL\n");
 167                 return -EIO;
 168         }
 169
 170         if (writing && (x & CSR_RXAK)) {
 171                 dev_dbg(i2c->dev, "No RXAK\n");
 172                 /* generate stop */
 173                 writeccr(i2c, CCR_MEN);
 174                 return -EIO;
 175         }
 176         return 0;
 177 }
 178
 179 #if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
 180 static 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
 201 static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
 202                                           int prescaler, 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
 235 static void mpc_i2c_setup_52xx(struct device_node *node,
 236                                          struct mpc_i2c *i2c,
 237                                          u32 clock, u32 prescaler)
 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, prescaler, &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) */
 257 static void mpc_i2c_setup_52xx(struct device_node *node,
 258                                          struct mpc_i2c *i2c,
 259                                          u32 clock, u32 prescaler)
 260 {
 261 }
 262 #endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
 263
 264 #ifdef CONFIG_PPC_MPC512x
 265 static void mpc_i2c_setup_512x(struct device_node *node,
 266                                          struct mpc_i2c *i2c,
 267                                          u32 clock, u32 prescaler)
 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, prescaler);
 291 }
 292 #else /* CONFIG_PPC_MPC512x */
 293 static void mpc_i2c_setup_512x(struct device_node *node,
 294                                          struct mpc_i2c *i2c,
 295                                          u32 clock, u32 prescaler)
 296 {
 297 }
 298 #endif /* CONFIG_PPC_MPC512x */
 299
 300 #ifdef CONFIG_FSL_SOC
 301 static 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
 321 static u32 mpc_i2c_get_sec_cfg_8xxx(void)
 322 {
 323         struct device_node *node = NULL;
 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
 334                          */
 335                         reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
 336                         if (!reg)
 337                                 printk(KERN_ERR
 338                                        "Error: couldn't map PORDEVSR2\n");
 339                         else
 340                                 val = in_be32(reg) & 0x00000080; /* sec-cfg */
 341                         iounmap(reg);
 342                 }
 343         }
 344         if (node)
 345                 of_node_put(node);
 346
 347         return val;
 348 }
 349
 350 static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
 351                                           u32 prescaler, u32 *real_clk)
 352 {
 353         const struct mpc_i2c_divider *div = NULL;
 354         u32 divider;
 355         int i;
 356
 357         if (clock == MPC_I2C_CLOCK_LEGACY) {
 358                 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
 359                 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
 360                 return -EINVAL;
 361         }
 362
 363         /* Determine proper divider value */
 364         if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
 365                 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
 366         if (!prescaler)
 367                 prescaler = 1;
 368
 369         divider = fsl_get_sys_freq() / clock / prescaler;
 370
 371         pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
 372                  fsl_get_sys_freq(), clock, divider);
 373
 374         /*
 375          * We want to choose an FDR/DFSR that generates an I2C bus speed that
 376          * is equal to or lower than the requested speed.
 377          */
 378         for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
 379                 div = &mpc_i2c_dividers_8xxx[i];
 380                 if (div->divider >= divider)
 381                         break;
 382         }
 383
 384         *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
 385         return div ? (int)div->fdr : -EINVAL;
 386 }
 387
 388 static void mpc_i2c_setup_8xxx(struct device_node *node,
 389                                          struct mpc_i2c *i2c,
 390                                          u32 clock, u32 prescaler)
 391 {
 392         int ret, fdr;
 393
 394         if (clock == MPC_I2C_CLOCK_PRESERVE) {
 395                 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
 396                         readb(i2c->base + MPC_I2C_DFSRR),
 397                         readb(i2c->base + MPC_I2C_FDR));
 398                 return;
 399         }
 400
 401         ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
 402         fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
 403
 404         writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 405         writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
 406
 407         if (ret >= 0)
 408                 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
 409                          i2c->real_clk, fdr >> 8, fdr & 0xff);
 410 }
 411
 412 #else /* !CONFIG_FSL_SOC */
 413 static void mpc_i2c_setup_8xxx(struct device_node *node,
 414                                          struct mpc_i2c *i2c,
 415                                          u32 clock, u32 prescaler)
 416 {
 417 }
 418 #endif /* CONFIG_FSL_SOC */
 419
 420 static void mpc_i2c_start(struct mpc_i2c *i2c)
 421 {
 422         /* Clear arbitration */
 423         writeb(0, i2c->base + MPC_I2C_SR);
 424         /* Start with MEN */
 425         writeccr(i2c, CCR_MEN);
 426 }
 427
 428 static void mpc_i2c_stop(struct mpc_i2c *i2c)
 429 {
 430         writeccr(i2c, CCR_MEN);
 431 }
 432
 433 static int mpc_write(struct mpc_i2c *i2c, int target,
 434                      const u8 *data, int length, int restart)
 435 {
 436         int i, result;
 437         unsigned timeout = i2c->adap.timeout;
 438         u32 flags = restart ? CCR_RSTA : 0;
 439
 440         /* Start as master */
 441         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 442         /* Write target byte */
 443         writeb((target << 1), i2c->base + MPC_I2C_DR);
 444
 445         result = i2c_wait(i2c, timeout, 1);
 446         if (result < 0)
 447                 return result;
 448
 449         for (i = 0; i < length; i++) {
 450                 /* Write data byte */
 451                 writeb(data[i], i2c->base + MPC_I2C_DR);
 452
 453                 result = i2c_wait(i2c, timeout, 1);
 454                 if (result < 0)
 455                         return result;
 456         }
 457
 458         return 0;
 459 }
 460
 461 static int mpc_read(struct mpc_i2c *i2c, int target,
 462                     u8 *data, int length, int restart, bool recv_len)
 463 {
 464         unsigned timeout = i2c->adap.timeout;
 465         int i, result;
 466         u32 flags = restart ? CCR_RSTA : 0;
 467
 468         /* Switch to read - restart */
 469         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 470         /* Write target address byte - this time with the read flag set */
 471         writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
 472
 473         result = i2c_wait(i2c, timeout, 1);
 474         if (result < 0)
 475                 return result;
 476
 477         if (length) {
 478                 if (length == 1 && !recv_len)
 479                         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 480                 else
 481                         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
 482                 /* Dummy read */
 483                 readb(i2c->base + MPC_I2C_DR);
 484         }
 485
 486         for (i = 0; i < length; i++) {
 487                 u8 byte;
 488
 489                 result = i2c_wait(i2c, timeout, 0);
 490                 if (result < 0)
 491                         return result;
 492
 493                 /*
 494                  * For block reads, we have to know the total length (1st byte)
 495                  * before we can determine if we are done.
 496                  */
 497                 if (i || !recv_len) {
 498                         /* Generate txack on next to last byte */
 499                         if (i == length - 2)
 500                                 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 501                                          | CCR_TXAK);
 502                         /* Do not generate stop on last byte */
 503                         if (i == length - 1)
 504                                 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 505                                          | CCR_MTX);
 506                 }
 507
 508                 byte = readb(i2c->base + MPC_I2C_DR);
 509
 510                 /*
 511                  * Adjust length if first received byte is length.
 512                  * The length is 1 length byte plus actually data length
 513                  */
 514                 if (i == 0 && recv_len) {
 515                         if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
 516                                 return -EPROTO;
 517                         length += byte;
 518                         /*
 519                          * For block reads, generate txack here if data length
 520                          * is 1 byte (total length is 2 bytes).
 521                          */
 522                         if (length == 2)
 523                                 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 524                                          | CCR_TXAK);
 525                 }
 526                 data[i] = byte;
 527         }
 528
 529         return length;
 530 }
 531
 532 static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 533 {
 534         struct i2c_msg *pmsg;
 535         int i;
 536         int ret = 0;
 537         unsigned long orig_jiffies = jiffies;
 538         struct mpc_i2c *i2c = i2c_get_adapdata(adap);
 539
 540         mpc_i2c_start(i2c);
 541
 542         /* Allow bus up to 1s to become not busy */
 543         while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 544                 if (signal_pending(current)) {
 545                         dev_dbg(i2c->dev, "Interrupted\n");
 546                         writeccr(i2c, 0);
 547                         return -EINTR;
 548                 }
 549                 if (time_after(jiffies, orig_jiffies + HZ)) {
 550                         u8 status = readb(i2c->base + MPC_I2C_SR);
 551
 552                         dev_dbg(i2c->dev, "timeout\n");
 553                         if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 554                                 writeb(status & ~CSR_MAL,
 555                                        i2c->base + MPC_I2C_SR);
 556                                 mpc_i2c_fixup(i2c);
 557                         }
 558                         return -EIO;
 559                 }
 560                 schedule();
 561         }
 562
 563         for (i = 0; ret >= 0 && i < num; i++) {
 564                 pmsg = &msgs[i];
 565                 dev_dbg(i2c->dev,
 566                         "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 567                         pmsg->flags & I2C_M_RD ? "read" : "write",
 568                         pmsg->len, pmsg->addr, i + 1, num);
 569                 if (pmsg->flags & I2C_M_RD) {
 570                         bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
 571
 572                         ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
 573                                        recv_len);
 574                         if (recv_len && ret > 0)
 575                                 pmsg->len = ret;
 576                 } else {
 577                         ret =
 578                             mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
 579                 }
 580         }
 581         mpc_i2c_stop(i2c); /* Initiate STOP */
 582         orig_jiffies = jiffies;
 583         /* Wait until STOP is seen, allow up to 1 s */
 584         while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 585                 if (time_after(jiffies, orig_jiffies + HZ)) {
 586                         u8 status = readb(i2c->base + MPC_I2C_SR);
 587
 588                         dev_dbg(i2c->dev, "timeout\n");
 589                         if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 590                                 writeb(status & ~CSR_MAL,
 591                                        i2c->base + MPC_I2C_SR);
 592                                 mpc_i2c_fixup(i2c);
 593                         }
 594                         return -EIO;
 595                 }
 596                 cond_resched();
 597         }
 598         return (ret < 0) ? ret : num;
 599 }
 600
 601 static u32 mpc_functionality(struct i2c_adapter *adap)
 602 {
 603         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
 604           | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 605 }
 606
 607 static const struct i2c_algorithm mpc_algo = {
 608         .master_xfer = mpc_xfer,
 609         .functionality = mpc_functionality,
 610 };
 611
 612 static struct i2c_adapter mpc_ops = {
 613         .owner = THIS_MODULE,
 614         .algo = &mpc_algo,
 615         .timeout = HZ,
 616 };
 617
 618 static const struct of_device_id mpc_i2c_of_match[];
 619 static int fsl_i2c_probe(struct platform_device *op)
 620 {
 621         const struct of_device_id *match;
 622         struct mpc_i2c *i2c;
 623         const u32 *prop;
 624         u32 clock = MPC_I2C_CLOCK_LEGACY;
 625         int result = 0;
 626         int plen;
 627         struct resource res;
 628         struct clk *clk;
 629         int err;
 630
 631         match = of_match_device(mpc_i2c_of_match, &op->dev);
 632         if (!match)
 633                 return -EINVAL;
 634
 635         i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
 636         if (!i2c)
 637                 return -ENOMEM;
 638
 639         i2c->dev = &op->dev; /* for debug and error output */
 640
 641         init_waitqueue_head(&i2c->queue);
 642
 643         i2c->base = of_iomap(op->dev.of_node, 0);
 644         if (!i2c->base) {
 645                 dev_err(i2c->dev, "failed to map controller\n");
 646                 result = -ENOMEM;
 647                 goto fail_map;
 648         }
 649
 650         i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
 651         if (i2c->irq) { /* no i2c->irq implies polling */
 652                 result = request_irq(i2c->irq, mpc_i2c_isr,
 653                                      IRQF_SHARED, "i2c-mpc", i2c);
 654                 if (result < 0) {
 655                         dev_err(i2c->dev, "failed to attach interrupt\n");
 656                         goto fail_request;
 657                 }
 658         }
 659
 660         /*
 661          * enable clock for the I2C peripheral (non fatal),
 662          * keep a reference upon successful allocation
 663          */
 664         clk = devm_clk_get(&op->dev, NULL);
 665         if (!IS_ERR(clk)) {
 666                 err = clk_prepare_enable(clk);
 667                 if (err) {
 668                         dev_err(&op->dev, "failed to enable clock\n");
 669                         goto fail_request;
 670                 } else {
 671                         i2c->clk_per = clk;
 672                 }
 673         }
 674
 675         if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) {
 676                 clock = MPC_I2C_CLOCK_PRESERVE;
 677         } else {
 678                 prop = of_get_property(op->dev.of_node, "clock-frequency",
 679                                         &plen);
 680                 if (prop && plen == sizeof(u32))
 681                         clock = *prop;
 682         }
 683
 684         if (match->data) {
 685                 const struct mpc_i2c_data *data = match->data;
 686                 data->setup(op->dev.of_node, i2c, clock, data->prescaler);
 687         } else {
 688                 /* Backwards compatibility */
 689                 if (of_get_property(op->dev.of_node, "dfsrr", NULL))
 690                         mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
 691         }
 692
 693         prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
 694         if (prop && plen == sizeof(u32)) {
 695                 mpc_ops.timeout = *prop * HZ / 1000000;
 696                 if (mpc_ops.timeout < 5)
 697                         mpc_ops.timeout = 5;
 698         }
 699         dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
 700
 701         platform_set_drvdata(op, i2c);
 702
 703         i2c->adap = mpc_ops;
 704         of_address_to_resource(op->dev.of_node, 0, &res);
 705         scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
 706                   "MPC adapter at 0x%llx", (unsigned long long)res.start);
 707         i2c_set_adapdata(&i2c->adap, i2c);
 708         i2c->adap.dev.parent = &op->dev;
 709         i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
 710
 711         result = i2c_add_adapter(&i2c->adap);
 712         if (result < 0) {
 713                 dev_err(i2c->dev, "failed to add adapter\n");
 714                 goto fail_add;
 715         }
 716
 717         return result;
 718
 719  fail_add:
 720         if (i2c->clk_per)
 721                 clk_disable_unprepare(i2c->clk_per);
 722         free_irq(i2c->irq, i2c);
 723  fail_request:
 724         irq_dispose_mapping(i2c->irq);
 725         iounmap(i2c->base);
 726  fail_map:
 727         kfree(i2c);
 728         return result;
 729 };
 730
 731 static int fsl_i2c_remove(struct platform_device *op)
 732 {
 733         struct mpc_i2c *i2c = platform_get_drvdata(op);
 734
 735         i2c_del_adapter(&i2c->adap);
 736
 737         if (i2c->clk_per)
 738                 clk_disable_unprepare(i2c->clk_per);
 739
 740         if (i2c->irq)
 741                 free_irq(i2c->irq, i2c);
 742
 743         irq_dispose_mapping(i2c->irq);
 744         iounmap(i2c->base);
 745         kfree(i2c);
 746         return 0;
 747 };
 748
 749 #ifdef CONFIG_PM_SLEEP
 750 static int mpc_i2c_suspend(struct device *dev)
 751 {
 752         struct mpc_i2c *i2c = dev_get_drvdata(dev);
 753
 754         i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
 755         i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
 756
 757         return 0;
 758 }
 759
 760 static int mpc_i2c_resume(struct device *dev)
 761 {
 762         struct mpc_i2c *i2c = dev_get_drvdata(dev);
 763
 764         writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
 765         writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
 766
 767         return 0;
 768 }
 769
 770 static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
 771 #define MPC_I2C_PM_OPS  (&mpc_i2c_pm_ops)
 772 #else
 773 #define MPC_I2C_PM_OPS  NULL
 774 #endif
 775
 776 static const struct mpc_i2c_data mpc_i2c_data_512x = {
 777         .setup = mpc_i2c_setup_512x,
 778 };
 779
 780 static const struct mpc_i2c_data mpc_i2c_data_52xx = {
 781         .setup = mpc_i2c_setup_52xx,
 782 };
 783
 784 static const struct mpc_i2c_data mpc_i2c_data_8313 = {
 785         .setup = mpc_i2c_setup_8xxx,
 786 };
 787
 788 static const struct mpc_i2c_data mpc_i2c_data_8543 = {
 789         .setup = mpc_i2c_setup_8xxx,
 790         .prescaler = 2,
 791 };
 792
 793 static const struct mpc_i2c_data mpc_i2c_data_8544 = {
 794         .setup = mpc_i2c_setup_8xxx,
 795         .prescaler = 3,
 796 };
 797
 798 static const struct of_device_id mpc_i2c_of_match[] = {
 799         {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 800         {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
 801         {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 802         {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
 803         {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
 804         {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
 805         {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
 806         /* Backward compatibility */
 807         {.compatible = "fsl-i2c", },
 808         {},
 809 };
 810 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
 811
 812 /* Structure for a device driver */
 813 static struct platform_driver mpc_i2c_driver = {
 814         .probe          = fsl_i2c_probe,
 815         .remove         = fsl_i2c_remove,
 816         .driver = {
 817                 .owner = THIS_MODULE,
 818                 .name = DRV_NAME,
 819                 .of_match_table = mpc_i2c_of_match,
 820                 .pm = MPC_I2C_PM_OPS,
 821         },
 822 };
 823
 824 module_platform_driver(mpc_i2c_driver);
 825
 826 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 827 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
 828                    "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 829 MODULE_LICENSE("GPL");