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_address.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/slab.h>
  24
  25 #include <linux/clk.h>
  26 #include <linux/io.h>
  27 #include <linux/fsl_devices.h>
  28 #include <linux/i2c.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/delay.h>
  31
  32 #include <asm/mpc52xx.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
  61 struct 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
  75 struct mpc_i2c_divider {
  76         u16 divider;
  77         u16 fdr;        /* including dfsrr */
  78 };
  79
  80 struct mpc_i2c_data {
  81         void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
  82                       u32 clock, u32 prescaler);
  83         u32 prescaler;
  84 };
  85
  86 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
  87 {
  88         writeb(x, i2c->base + MPC_I2C_CR);
  89 }
  90
  91 static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
  92 {
  93         struct mpc_i2c *i2c = dev_id;
  94         if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
  95                 /* Read again to allow register to stabilise */
  96                 i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
  97                 writeb(0, i2c->base + MPC_I2C_SR);
  98                 wake_up(&i2c->queue);
  99         }
 100         return IRQ_HANDLED;
 101 }
 102
 103 /* Sometimes 9th clock pulse isn't generated, and slave doesn't release
 104  * the bus, because it wants to send ACK.
 105  * Following sequence of enabling/disabling and sending start/stop generates
 106  * the 9 pulses, so it's all OK.
 107  */
 108 static void mpc_i2c_fixup(struct mpc_i2c *i2c)
 109 {
 110         int k;
 111         u32 delay_val = 1000000 / i2c->real_clk + 1;
 112
 113         if (delay_val < 2)
 114                 delay_val = 2;
 115
 116         for (k = 9; k; k--) {
 117                 writeccr(i2c, 0);
 118                 writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
 119                 udelay(delay_val);
 120                 writeccr(i2c, CCR_MEN);
 121                 udelay(delay_val << 1);
 122         }
 123 }
 124
 125 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 126 {
 127         unsigned long orig_jiffies = jiffies;
 128         u32 x;
 129         int result = 0;
 130
 131         if (!i2c->irq) {
 132                 while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
 133                         schedule();
 134                         if (time_after(jiffies, orig_jiffies + timeout)) {
 135                                 dev_dbg(i2c->dev, "timeout\n");
 136                                 writeccr(i2c, 0);
 137                                 result = -EIO;
 138                                 break;
 139                         }
 140                 }
 141                 x = readb(i2c->base + MPC_I2C_SR);
 142                 writeb(0, i2c->base + MPC_I2C_SR);
 143         } else {
 144                 /* Interrupt mode */
 145                 result = wait_event_timeout(i2c->queue,
 146                         (i2c->interrupt & CSR_MIF), timeout);
 147
 148                 if (unlikely(!(i2c->interrupt & CSR_MIF))) {
 149                         dev_dbg(i2c->dev, "wait timeout\n");
 150                         writeccr(i2c, 0);
 151                         result = -ETIMEDOUT;
 152                 }
 153
 154                 x = i2c->interrupt;
 155                 i2c->interrupt = 0;
 156         }
 157
 158         if (result < 0)
 159                 return result;
 160
 161         if (!(x & CSR_MCF)) {
 162                 dev_dbg(i2c->dev, "unfinished\n");
 163                 return -EIO;
 164         }
 165
 166         if (x & CSR_MAL) {
 167                 dev_dbg(i2c->dev, "MAL\n");
 168                 return -EIO;
 169         }
 170
 171         if (writing && (x & CSR_RXAK)) {
 172                 dev_dbg(i2c->dev, "No RXAK\n");
 173                 /* generate stop */
 174                 writeccr(i2c, CCR_MEN);
 175                 return -EIO;
 176         }
 177         return 0;
 178 }
 179
 180 #if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
 181 static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
 182         {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
 183         {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
 184         {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
 185         {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
 186         {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
 187         {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
 188         {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
 189         {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
 190         {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
 191         {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
 192         {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
 193         {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
 194         {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
 195         {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
 196         {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
 197         {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
 198         {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
 199         {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
 200 };
 201
 202 static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
 203                                           int prescaler, u32 *real_clk)
 204 {
 205         const struct mpc_i2c_divider *div = NULL;
 206         unsigned int pvr = mfspr(SPRN_PVR);
 207         u32 divider;
 208         int i;
 209
 210         if (clock == MPC_I2C_CLOCK_LEGACY) {
 211                 /* see below - default fdr = 0x3f -> div = 2048 */
 212                 *real_clk = mpc5xxx_get_bus_frequency(node) / 2048;
 213                 return -EINVAL;
 214         }
 215
 216         /* Determine divider value */
 217         divider = mpc5xxx_get_bus_frequency(node) / clock;
 218
 219         /*
 220          * We want to choose an FDR/DFSR that generates an I2C bus speed that
 221          * is equal to or lower than the requested speed.
 222          */
 223         for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
 224                 div = &mpc_i2c_dividers_52xx[i];
 225                 /* Old MPC5200 rev A CPUs do not support the high bits */
 226                 if (div->fdr & 0xc0 && pvr == 0x80822011)
 227                         continue;
 228                 if (div->divider >= divider)
 229                         break;
 230         }
 231
 232         *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider;
 233         return (int)div->fdr;
 234 }
 235
 236 static void mpc_i2c_setup_52xx(struct device_node *node,
 237                                          struct mpc_i2c *i2c,
 238                                          u32 clock, u32 prescaler)
 239 {
 240         int ret, fdr;
 241
 242         if (clock == MPC_I2C_CLOCK_PRESERVE) {
 243                 dev_dbg(i2c->dev, "using fdr %d\n",
 244                         readb(i2c->base + MPC_I2C_FDR));
 245                 return;
 246         }
 247
 248         ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk);
 249         fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
 250
 251         writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 252
 253         if (ret >= 0)
 254                 dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
 255                          fdr);
 256 }
 257 #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
 258 static void mpc_i2c_setup_52xx(struct device_node *node,
 259                                          struct mpc_i2c *i2c,
 260                                          u32 clock, u32 prescaler)
 261 {
 262 }
 263 #endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
 264
 265 #ifdef CONFIG_PPC_MPC512x
 266 static void mpc_i2c_setup_512x(struct device_node *node,
 267                                          struct mpc_i2c *i2c,
 268                                          u32 clock, u32 prescaler)
 269 {
 270         struct device_node *node_ctrl;
 271         void __iomem *ctrl;
 272         const u32 *pval;
 273         u32 idx;
 274
 275         /* Enable I2C interrupts for mpc5121 */
 276         node_ctrl = of_find_compatible_node(NULL, NULL,
 277                                             "fsl,mpc5121-i2c-ctrl");
 278         if (node_ctrl) {
 279                 ctrl = of_iomap(node_ctrl, 0);
 280                 if (ctrl) {
 281                         /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
 282                         pval = of_get_property(node, "reg", NULL);
 283                         idx = (*pval & 0xff) / 0x20;
 284                         setbits32(ctrl, 1 << (24 + idx * 2));
 285                         iounmap(ctrl);
 286                 }
 287                 of_node_put(node_ctrl);
 288         }
 289
 290         /* The clock setup for the 52xx works also fine for the 512x */
 291         mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
 292 }
 293 #else /* CONFIG_PPC_MPC512x */
 294 static void mpc_i2c_setup_512x(struct device_node *node,
 295                                          struct mpc_i2c *i2c,
 296                                          u32 clock, u32 prescaler)
 297 {
 298 }
 299 #endif /* CONFIG_PPC_MPC512x */
 300
 301 #ifdef CONFIG_FSL_SOC
 302 static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
 303         {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
 304         {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
 305         {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
 306         {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
 307         {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
 308         {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
 309         {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
 310         {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
 311         {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
 312         {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
 313         {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
 314         {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
 315         {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
 316         {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
 317         {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
 318         {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
 319         {49152, 0x011e}, {61440, 0x011f}
 320 };
 321
 322 static u32 mpc_i2c_get_sec_cfg_8xxx(void)
 323 {
 324         struct device_node *node = NULL;
 325         u32 __iomem *reg;
 326         u32 val = 0;
 327
 328         node = of_find_node_by_name(NULL, "global-utilities");
 329         if (node) {
 330                 const u32 *prop = of_get_property(node, "reg", NULL);
 331                 if (prop) {
 332                         /*
 333                          * Map and check POR Device Status Register 2
 334                          * (PORDEVSR2) at 0xE0014
 335                          */
 336                         reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
 337                         if (!reg)
 338                                 printk(KERN_ERR
 339                                        "Error: couldn't map PORDEVSR2\n");
 340                         else
 341                                 val = in_be32(reg) & 0x00000080; /* sec-cfg */
 342                         iounmap(reg);
 343                 }
 344         }
 345         if (node)
 346                 of_node_put(node);
 347
 348         return val;
 349 }
 350
 351 static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
 352                                           u32 prescaler, u32 *real_clk)
 353 {
 354         const struct mpc_i2c_divider *div = NULL;
 355         u32 divider;
 356         int i;
 357
 358         if (clock == MPC_I2C_CLOCK_LEGACY) {
 359                 /* see below - default fdr = 0x1031 -> div = 16 * 3072 */
 360                 *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
 361                 return -EINVAL;
 362         }
 363
 364         /* Determine proper divider value */
 365         if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
 366                 prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
 367         if (!prescaler)
 368                 prescaler = 1;
 369
 370         divider = fsl_get_sys_freq() / clock / prescaler;
 371
 372         pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
 373                  fsl_get_sys_freq(), clock, divider);
 374
 375         /*
 376          * We want to choose an FDR/DFSR that generates an I2C bus speed that
 377          * is equal to or lower than the requested speed.
 378          */
 379         for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
 380                 div = &mpc_i2c_dividers_8xxx[i];
 381                 if (div->divider >= divider)
 382                         break;
 383         }
 384
 385         *real_clk = fsl_get_sys_freq() / prescaler / div->divider;
 386         return div ? (int)div->fdr : -EINVAL;
 387 }
 388
 389 static void mpc_i2c_setup_8xxx(struct device_node *node,
 390                                          struct mpc_i2c *i2c,
 391                                          u32 clock, u32 prescaler)
 392 {
 393         int ret, fdr;
 394
 395         if (clock == MPC_I2C_CLOCK_PRESERVE) {
 396                 dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
 397                         readb(i2c->base + MPC_I2C_DFSRR),
 398                         readb(i2c->base + MPC_I2C_FDR));
 399                 return;
 400         }
 401
 402         ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
 403         fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
 404
 405         writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
 406         writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
 407
 408         if (ret >= 0)
 409                 dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
 410                          i2c->real_clk, fdr >> 8, fdr & 0xff);
 411 }
 412
 413 #else /* !CONFIG_FSL_SOC */
 414 static void mpc_i2c_setup_8xxx(struct device_node *node,
 415                                          struct mpc_i2c *i2c,
 416                                          u32 clock, u32 prescaler)
 417 {
 418 }
 419 #endif /* CONFIG_FSL_SOC */
 420
 421 static void mpc_i2c_start(struct mpc_i2c *i2c)
 422 {
 423         /* Clear arbitration */
 424         writeb(0, i2c->base + MPC_I2C_SR);
 425         /* Start with MEN */
 426         writeccr(i2c, CCR_MEN);
 427 }
 428
 429 static void mpc_i2c_stop(struct mpc_i2c *i2c)
 430 {
 431         writeccr(i2c, CCR_MEN);
 432 }
 433
 434 static int mpc_write(struct mpc_i2c *i2c, int target,
 435                      const u8 *data, int length, int restart)
 436 {
 437         int i, result;
 438         unsigned timeout = i2c->adap.timeout;
 439         u32 flags = restart ? CCR_RSTA : 0;
 440
 441         /* Start as master */
 442         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 443         /* Write target byte */
 444         writeb((target << 1), i2c->base + MPC_I2C_DR);
 445
 446         result = i2c_wait(i2c, timeout, 1);
 447         if (result < 0)
 448                 return result;
 449
 450         for (i = 0; i < length; i++) {
 451                 /* Write data byte */
 452                 writeb(data[i], i2c->base + MPC_I2C_DR);
 453
 454                 result = i2c_wait(i2c, timeout, 1);
 455                 if (result < 0)
 456                         return result;
 457         }
 458
 459         return 0;
 460 }
 461
 462 static int mpc_read(struct mpc_i2c *i2c, int target,
 463                     u8 *data, int length, int restart, bool recv_len)
 464 {
 465         unsigned timeout = i2c->adap.timeout;
 466         int i, result;
 467         u32 flags = restart ? CCR_RSTA : 0;
 468
 469         /* Switch to read - restart */
 470         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 471         /* Write target address byte - this time with the read flag set */
 472         writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
 473
 474         result = i2c_wait(i2c, timeout, 1);
 475         if (result < 0)
 476                 return result;
 477
 478         if (length) {
 479                 if (length == 1 && !recv_len)
 480                         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 481                 else
 482                         writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
 483                 /* Dummy read */
 484                 readb(i2c->base + MPC_I2C_DR);
 485         }
 486
 487         for (i = 0; i < length; i++) {
 488                 u8 byte;
 489
 490                 result = i2c_wait(i2c, timeout, 0);
 491                 if (result < 0)
 492                         return result;
 493
 494                 /*
 495                  * For block reads, we have to know the total length (1st byte)
 496                  * before we can determine if we are done.
 497                  */
 498                 if (i || !recv_len) {
 499                         /* Generate txack on next to last byte */
 500                         if (i == length - 2)
 501                                 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 502                                          | CCR_TXAK);
 503                         /* Do not generate stop on last byte */
 504                         if (i == length - 1)
 505                                 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 506                                          | CCR_MTX);
 507                 }
 508
 509                 byte = readb(i2c->base + MPC_I2C_DR);
 510
 511                 /*
 512                  * Adjust length if first received byte is length.
 513                  * The length is 1 length byte plus actually data length
 514                  */
 515                 if (i == 0 && recv_len) {
 516                         if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
 517                                 return -EPROTO;
 518                         length += byte;
 519                         /*
 520                          * For block reads, generate txack here if data length
 521                          * is 1 byte (total length is 2 bytes).
 522                          */
 523                         if (length == 2)
 524                                 writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
 525                                          | CCR_TXAK);
 526                 }
 527                 data[i] = byte;
 528         }
 529
 530         return length;
 531 }
 532
 533 static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 534 {
 535         struct i2c_msg *pmsg;
 536         int i;
 537         int ret = 0;
 538         unsigned long orig_jiffies = jiffies;
 539         struct mpc_i2c *i2c = i2c_get_adapdata(adap);
 540
 541         mpc_i2c_start(i2c);
 542
 543         /* Allow bus up to 1s to become not busy */
 544         while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 545                 if (signal_pending(current)) {
 546                         dev_dbg(i2c->dev, "Interrupted\n");
 547                         writeccr(i2c, 0);
 548                         return -EINTR;
 549                 }
 550                 if (time_after(jiffies, orig_jiffies + HZ)) {
 551                         u8 status = readb(i2c->base + MPC_I2C_SR);
 552
 553                         dev_dbg(i2c->dev, "timeout\n");
 554                         if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 555                                 writeb(status & ~CSR_MAL,
 556                                        i2c->base + MPC_I2C_SR);
 557                                 mpc_i2c_fixup(i2c);
 558                         }
 559                         return -EIO;
 560                 }
 561                 schedule();
 562         }
 563
 564         for (i = 0; ret >= 0 && i < num; i++) {
 565                 pmsg = &msgs[i];
 566                 dev_dbg(i2c->dev,
 567                         "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 568                         pmsg->flags & I2C_M_RD ? "read" : "write",
 569                         pmsg->len, pmsg->addr, i + 1, num);
 570                 if (pmsg->flags & I2C_M_RD) {
 571                         bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
 572
 573                         ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
 574                                        recv_len);
 575                         if (recv_len && ret > 0)
 576                                 pmsg->len = ret;
 577                 } else {
 578                         ret =
 579                             mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
 580                 }
 581         }
 582         mpc_i2c_stop(i2c); /* Initiate STOP */
 583         orig_jiffies = jiffies;
 584         /* Wait until STOP is seen, allow up to 1 s */
 585         while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 586                 if (time_after(jiffies, orig_jiffies + HZ)) {
 587                         u8 status = readb(i2c->base + MPC_I2C_SR);
 588
 589                         dev_dbg(i2c->dev, "timeout\n");
 590                         if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
 591                                 writeb(status & ~CSR_MAL,
 592                                        i2c->base + MPC_I2C_SR);
 593                                 mpc_i2c_fixup(i2c);
 594                         }
 595                         return -EIO;
 596                 }
 597                 cond_resched();
 598         }
 599         return (ret < 0) ? ret : num;
 600 }
 601
 602 static u32 mpc_functionality(struct i2c_adapter *adap)
 603 {
 604         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
 605           | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 606 }
 607
 608 static const struct i2c_algorithm mpc_algo = {
 609         .master_xfer = mpc_xfer,
 610         .functionality = mpc_functionality,
 611 };
 612
 613 static struct i2c_adapter mpc_ops = {
 614         .owner = THIS_MODULE,
 615         .algo = &mpc_algo,
 616         .timeout = HZ,
 617 };
 618
 619 static const struct of_device_id mpc_i2c_of_match[];
 620 static int fsl_i2c_probe(struct platform_device *op)
 621 {
 622         const struct of_device_id *match;
 623         struct mpc_i2c *i2c;
 624         const u32 *prop;
 625         u32 clock = MPC_I2C_CLOCK_LEGACY;
 626         int result = 0;
 627         int plen;
 628         struct resource res;
 629         struct clk *clk;
 630         int err;
 631
 632         match = of_match_device(mpc_i2c_of_match, &op->dev);
 633         if (!match)
 634                 return -EINVAL;
 635
 636         i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
 637         if (!i2c)
 638                 return -ENOMEM;
 639
 640         i2c->dev = &op->dev; /* for debug and error output */
 641
 642         init_waitqueue_head(&i2c->queue);
 643
 644         i2c->base = of_iomap(op->dev.of_node, 0);
 645         if (!i2c->base) {
 646                 dev_err(i2c->dev, "failed to map controller\n");
 647                 result = -ENOMEM;
 648                 goto fail_map;
 649         }
 650
 651         i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
 652         if (i2c->irq) { /* no i2c->irq implies polling */
 653                 result = request_irq(i2c->irq, mpc_i2c_isr,
 654                                      IRQF_SHARED, "i2c-mpc", i2c);
 655                 if (result < 0) {
 656                         dev_err(i2c->dev, "failed to attach interrupt\n");
 657                         goto fail_request;
 658                 }
 659         }
 660
 661         /*
 662          * enable clock for the I2C peripheral (non fatal),
 663          * keep a reference upon successful allocation
 664          */
 665         clk = devm_clk_get(&op->dev, NULL);
 666         if (!IS_ERR(clk)) {
 667                 err = clk_prepare_enable(clk);
 668                 if (err) {
 669                         dev_err(&op->dev, "failed to enable clock\n");
 670                         goto fail_request;
 671                 } else {
 672                         i2c->clk_per = clk;
 673                 }
 674         }
 675
 676         if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) {
 677                 clock = MPC_I2C_CLOCK_PRESERVE;
 678         } else {
 679                 prop = of_get_property(op->dev.of_node, "clock-frequency",
 680                                         &plen);
 681                 if (prop && plen == sizeof(u32))
 682                         clock = *prop;
 683         }
 684
 685         if (match->data) {
 686                 const struct mpc_i2c_data *data = match->data;
 687                 data->setup(op->dev.of_node, i2c, clock, data->prescaler);
 688         } else {
 689                 /* Backwards compatibility */
 690                 if (of_get_property(op->dev.of_node, "dfsrr", NULL))
 691                         mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
 692         }
 693
 694         prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
 695         if (prop && plen == sizeof(u32)) {
 696                 mpc_ops.timeout = *prop * HZ / 1000000;
 697                 if (mpc_ops.timeout < 5)
 698                         mpc_ops.timeout = 5;
 699         }
 700         dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
 701
 702         platform_set_drvdata(op, i2c);
 703
 704         i2c->adap = mpc_ops;
 705         of_address_to_resource(op->dev.of_node, 0, &res);
 706         scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
 707                   "MPC adapter at 0x%llx", (unsigned long long)res.start);
 708         i2c_set_adapdata(&i2c->adap, i2c);
 709         i2c->adap.dev.parent = &op->dev;
 710         i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
 711
 712         result = i2c_add_adapter(&i2c->adap);
 713         if (result < 0) {
 714                 dev_err(i2c->dev, "failed to add adapter\n");
 715                 goto fail_add;
 716         }
 717
 718         return result;
 719
 720  fail_add:
 721         if (i2c->clk_per)
 722                 clk_disable_unprepare(i2c->clk_per);
 723         free_irq(i2c->irq, i2c);
 724  fail_request:
 725         irq_dispose_mapping(i2c->irq);
 726         iounmap(i2c->base);
 727  fail_map:
 728         kfree(i2c);
 729         return result;
 730 };
 731
 732 static int fsl_i2c_remove(struct platform_device *op)
 733 {
 734         struct mpc_i2c *i2c = platform_get_drvdata(op);
 735
 736         i2c_del_adapter(&i2c->adap);
 737
 738         if (i2c->clk_per)
 739                 clk_disable_unprepare(i2c->clk_per);
 740
 741         if (i2c->irq)
 742                 free_irq(i2c->irq, i2c);
 743
 744         irq_dispose_mapping(i2c->irq);
 745         iounmap(i2c->base);
 746         kfree(i2c);
 747         return 0;
 748 };
 749
 750 #ifdef CONFIG_PM_SLEEP
 751 static int mpc_i2c_suspend(struct device *dev)
 752 {
 753         struct mpc_i2c *i2c = dev_get_drvdata(dev);
 754
 755         i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
 756         i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
 757
 758         return 0;
 759 }
 760
 761 static int mpc_i2c_resume(struct device *dev)
 762 {
 763         struct mpc_i2c *i2c = dev_get_drvdata(dev);
 764
 765         writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
 766         writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
 767
 768         return 0;
 769 }
 770
 771 static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
 772 #define MPC_I2C_PM_OPS  (&mpc_i2c_pm_ops)
 773 #else
 774 #define MPC_I2C_PM_OPS  NULL
 775 #endif
 776
 777 static const struct mpc_i2c_data mpc_i2c_data_512x = {
 778         .setup = mpc_i2c_setup_512x,
 779 };
 780
 781 static const struct mpc_i2c_data mpc_i2c_data_52xx = {
 782         .setup = mpc_i2c_setup_52xx,
 783 };
 784
 785 static const struct mpc_i2c_data mpc_i2c_data_8313 = {
 786         .setup = mpc_i2c_setup_8xxx,
 787 };
 788
 789 static const struct mpc_i2c_data mpc_i2c_data_8543 = {
 790         .setup = mpc_i2c_setup_8xxx,
 791         .prescaler = 2,
 792 };
 793
 794 static const struct mpc_i2c_data mpc_i2c_data_8544 = {
 795         .setup = mpc_i2c_setup_8xxx,
 796         .prescaler = 3,
 797 };
 798
 799 static const struct of_device_id mpc_i2c_of_match[] = {
 800         {.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 801         {.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
 802         {.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
 803         {.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
 804         {.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
 805         {.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
 806         {.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
 807         /* Backward compatibility */
 808         {.compatible = "fsl-i2c", },
 809         {},
 810 };
 811 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
 812
 813 /* Structure for a device driver */
 814 static struct platform_driver mpc_i2c_driver = {
 815         .probe          = fsl_i2c_probe,
 816         .remove         = fsl_i2c_remove,
 817         .driver = {
 818                 .owner = THIS_MODULE,
 819                 .name = DRV_NAME,
 820                 .of_match_table = mpc_i2c_of_match,
 821                 .pm = MPC_I2C_PM_OPS,
 822         },
 823 };
 824
 825 module_platform_driver(mpc_i2c_driver);
 826
 827 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 828 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
 829                    "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 830 MODULE_LICENSE("GPL");