target/linux/lantiq/patches-4.14/0031-I2C-MIPS-lantiq-add-FALC-ON-i2c-bus-master.patch

   1 From f17e50f67fa3c77624edf2ca03fae0d50f0ce39b Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Thu, 7 Aug 2014 18:26:42 +0200
   4 Subject: [PATCH 31/36] I2C: MIPS: lantiq: add FALC-ON i2c bus master
   5
   6 This patch adds the driver needed to make the I2C bus work on FALC-ON SoCs.
   7
   8 Signed-off-by: Thomas Langer <thomas.langer@lantiq.com>
   9 Signed-off-by: John Crispin <blogic@openwrt.org>
  10 ---
  11  drivers/i2c/busses/Kconfig      |   10 +
  12  drivers/i2c/busses/Makefile     |    1 +
  13  drivers/i2c/busses/i2c-lantiq.c |  747 +++++++++++++++++++++++++++++++++++++++
  14  drivers/i2c/busses/i2c-lantiq.h |  234 ++++++++++++
  15  4 files changed, 992 insertions(+)
  16  create mode 100644 drivers/i2c/busses/i2c-lantiq.c
  17  create mode 100644 drivers/i2c/busses/i2c-lantiq.h
  18
  19 --- a/drivers/i2c/busses/Kconfig
  20 +++ b/drivers/i2c/busses/Kconfig
  21 @@ -696,6 +696,16 @@ config I2C_MESON
  22           If you say yes to this option, support will be included for the
  23           I2C interface on the Amlogic Meson family of SoCs.
  24
  25 +config I2C_LANTIQ
  26 +       tristate "Lantiq I2C interface"
  27 +       depends on LANTIQ && SOC_FALCON
  28 +       help
  29 +         If you say yes to this option, support will be included for the
  30 +         Lantiq I2C core.
  31 +
  32 +         This driver can also be built as a module. If so, the module
  33 +         will be called i2c-lantiq.
  34 +
  35  config I2C_MPC
  36         tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
  37         depends on PPC
  38 --- a/drivers/i2c/busses/Makefile
  39 +++ b/drivers/i2c/busses/Makefile
  40 @@ -68,6 +68,7 @@ obj-$(CONFIG_I2C_IMX_LPI2C)   += i2c-imx-l
  41  obj-$(CONFIG_I2C_IOP3XX)       += i2c-iop3xx.o
  42  obj-$(CONFIG_I2C_JZ4780)       += i2c-jz4780.o
  43  obj-$(CONFIG_I2C_KEMPLD)       += i2c-kempld.o
  44 +obj-$(CONFIG_I2C_LANTIQ)       += i2c-lantiq.o
  45  obj-$(CONFIG_I2C_LPC2K)                += i2c-lpc2k.o
  46  obj-$(CONFIG_I2C_MESON)                += i2c-meson.o
  47  obj-$(CONFIG_I2C_MPC)          += i2c-mpc.o
  48 --- /dev/null
  49 +++ b/drivers/i2c/busses/i2c-lantiq.c
  50 @@ -0,0 +1,747 @@
  51 +
  52 +/*
  53 + * Lantiq I2C bus adapter
  54 + *
  55 + * Parts based on i2c-designware.c and other i2c drivers from Linux 2.6.33
  56 + *
  57 + * This program is free software; you can redistribute it and/or modify
  58 + * it under the terms of the GNU General Public License as published by
  59 + * the Free Software Foundation; either version 2 of the License, or
  60 + * (at your option) any later version.
  61 + *
  62 + * This program is distributed in the hope that it will be useful,
  63 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  64 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  65 + * GNU General Public License for more details.
  66 + *
  67 + * You should have received a copy of the GNU General Public License
  68 + * along with this program; if not, write to the Free Software
  69 + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  70 + *
  71 + * Copyright (C) 2012 Thomas Langer <thomas.langer@lantiq.com>
  72 + */
  73 +
  74 +#include <linux/kernel.h>
  75 +#include <linux/module.h>
  76 +#include <linux/delay.h>
  77 +#include <linux/slab.h> /* for kzalloc, kfree */
  78 +#include <linux/i2c.h>
  79 +#include <linux/errno.h>
  80 +#include <linux/completion.h>
  81 +#include <linux/interrupt.h>
  82 +#include <linux/platform_device.h>
  83 +#include <linux/io.h>
  84 +#include <linux/of_irq.h>
  85 +
  86 +#include <lantiq_soc.h>
  87 +#include "i2c-lantiq.h"
  88 +
  89 +/*
  90 + * CURRENT ISSUES:
  91 + * - no high speed support
  92 + * - ten bit mode is not tested (no slave devices)
  93 + */
  94 +
  95 +/* access macros */
  96 +#define i2c_r32(reg)   \
  97 +       __raw_readl(&(priv->membase)->reg)
  98 +#define i2c_w32(val, reg)      \
  99 +       __raw_writel(val, &(priv->membase)->reg)
 100 +#define i2c_w32_mask(clear, set, reg)  \
 101 +       i2c_w32((i2c_r32(reg) & ~(clear)) | (set), reg)
 102 +
 103 +#define DRV_NAME "i2c-lantiq"
 104 +#define DRV_VERSION "1.00"
 105 +
 106 +#define LTQ_I2C_BUSY_TIMEOUT           20 /* ms */
 107 +
 108 +#ifdef DEBUG
 109 +#define LTQ_I2C_XFER_TIMEOUT           (25*HZ)
 110 +#else
 111 +#define LTQ_I2C_XFER_TIMEOUT           HZ
 112 +#endif
 113 +
 114 +#define LTQ_I2C_IMSC_DEFAULT_MASK      (I2C_IMSC_I2C_P_INT_EN | \
 115 +                                        I2C_IMSC_I2C_ERR_INT_EN)
 116 +
 117 +#define LTQ_I2C_ARB_LOST               (1 << 0)
 118 +#define LTQ_I2C_NACK                   (1 << 1)
 119 +#define LTQ_I2C_RX_UFL                 (1 << 2)
 120 +#define LTQ_I2C_RX_OFL                 (1 << 3)
 121 +#define LTQ_I2C_TX_UFL                 (1 << 4)
 122 +#define LTQ_I2C_TX_OFL                 (1 << 5)
 123 +
 124 +struct ltq_i2c {
 125 +       struct mutex mutex;
 126 +
 127 +
 128 +       /* active clock settings */
 129 +       unsigned int input_clock;       /* clock input for i2c hardware block */
 130 +       unsigned int i2c_clock;         /* approximated bus clock in kHz */
 131 +
 132 +       struct clk *clk_gate;
 133 +       struct clk *clk_input;
 134 +
 135 +
 136 +       /* resources (memory and interrupts) */
 137 +       int irq_lb;                             /* last burst irq */
 138 +
 139 +       struct lantiq_reg_i2c __iomem *membase; /* base of mapped registers */
 140 +
 141 +       struct i2c_adapter adap;
 142 +       struct device *dev;
 143 +
 144 +       struct completion cmd_complete;
 145 +
 146 +
 147 +       /* message transfer data */
 148 +       struct i2c_msg *current_msg;    /* current message */
 149 +       int msgs_num;           /* number of messages to handle */
 150 +       u8 *msg_buf;            /* current buffer */
 151 +       u32 msg_buf_len;        /* remaining length of current buffer */
 152 +       int msg_err;            /* error status of the current transfer */
 153 +
 154 +
 155 +       /* master status codes */
 156 +       enum {
 157 +               STATUS_IDLE,
 158 +               STATUS_ADDR,    /* address phase */
 159 +               STATUS_WRITE,
 160 +               STATUS_READ,
 161 +               STATUS_READ_END,
 162 +               STATUS_STOP
 163 +       } status;
 164 +};
 165 +
 166 +static irqreturn_t ltq_i2c_isr(int irq, void *dev_id);
 167 +
 168 +static inline void enable_burst_irq(struct ltq_i2c *priv)
 169 +{
 170 +       i2c_w32_mask(0, I2C_IMSC_LBREQ_INT_EN | I2C_IMSC_BREQ_INT_EN, imsc);
 171 +}
 172 +static inline void disable_burst_irq(struct ltq_i2c *priv)
 173 +{
 174 +       i2c_w32_mask(I2C_IMSC_LBREQ_INT_EN | I2C_IMSC_BREQ_INT_EN, 0, imsc);
 175 +}
 176 +
 177 +static void prepare_msg_send_addr(struct ltq_i2c *priv)
 178 +{
 179 +       struct i2c_msg *msg = priv->current_msg;
 180 +       int rd = !!(msg->flags & I2C_M_RD);     /* extends to 0 or 1 */
 181 +       u16 addr = msg->addr;
 182 +
 183 +       /* new i2c_msg */
 184 +       priv->msg_buf = msg->buf;
 185 +       priv->msg_buf_len = msg->len;
 186 +       if (rd)
 187 +               priv->status = STATUS_READ;
 188 +       else
 189 +               priv->status = STATUS_WRITE;
 190 +
 191 +       /* send slave address */
 192 +       if (msg->flags & I2C_M_TEN) {
 193 +               i2c_w32(0xf0 | ((addr & 0x300) >> 7) | rd, txd);
 194 +               i2c_w32(addr & 0xff, txd);
 195 +       } else {
 196 +               i2c_w32((addr & 0x7f) << 1 | rd, txd);
 197 +       }
 198 +}
 199 +
 200 +static void ltq_i2c_set_tx_len(struct ltq_i2c *priv)
 201 +{
 202 +       struct i2c_msg *msg = priv->current_msg;
 203 +       int len = (msg->flags & I2C_M_TEN) ? 2 : 1;
 204 +
 205 +       pr_debug("set_tx_len %cX\n", (msg->flags & I2C_M_RD) ? 'R' : 'T');
 206 +
 207 +       priv->status = STATUS_ADDR;
 208 +
 209 +       if (!(msg->flags & I2C_M_RD))
 210 +               len += msg->len;
 211 +       else
 212 +               /* set maximum received packet size (before rx int!) */
 213 +               i2c_w32(msg->len, mrps_ctrl);
 214 +       i2c_w32(len, tps_ctrl);
 215 +       enable_burst_irq(priv);
 216 +}
 217 +
 218 +static int ltq_i2c_hw_set_clock(struct i2c_adapter *adap)
 219 +{
 220 +       struct ltq_i2c *priv = i2c_get_adapdata(adap);
 221 +       unsigned int input_clock = clk_get_rate(priv->clk_input);
 222 +       u32 dec, inc = 1;
 223 +
 224 +       /* clock changed? */
 225 +       if (priv->input_clock == input_clock)
 226 +               return 0;
 227 +
 228 +       /*
 229 +        * this formula is only an approximation, found by the recommended
 230 +        * values in the "I2C Architecture Specification 1.7.1"
 231 +        */
 232 +       dec = input_clock / (priv->i2c_clock * 2);
 233 +       if (dec <= 6)
 234 +               return -ENXIO;
 235 +
 236 +       i2c_w32(0, fdiv_high_cfg);
 237 +       i2c_w32((inc << I2C_FDIV_CFG_INC_OFFSET) |
 238 +               (dec << I2C_FDIV_CFG_DEC_OFFSET),
 239 +               fdiv_cfg);
 240 +
 241 +       dev_info(priv->dev, "setup clocks (in %d kHz, bus %d kHz, dec=%d)\n",
 242 +               input_clock, priv->i2c_clock, dec);
 243 +
 244 +       priv->input_clock = input_clock;
 245 +       return 0;
 246 +}
 247 +
 248 +static int ltq_i2c_hw_init(struct i2c_adapter *adap)
 249 +{
 250 +       int ret = 0;
 251 +       struct ltq_i2c *priv = i2c_get_adapdata(adap);
 252 +
 253 +       /* disable bus */
 254 +       i2c_w32_mask(I2C_RUN_CTRL_RUN_EN, 0, run_ctrl);
 255 +
 256 +#ifndef DEBUG
 257 +       /* set normal operation clock divider */
 258 +       i2c_w32(1 << I2C_CLC_RMC_OFFSET, clc);
 259 +#else
 260 +       /* for debugging a higher divider value! */
 261 +       i2c_w32(0xF0 << I2C_CLC_RMC_OFFSET, clc);
 262 +#endif
 263 +
 264 +       /* setup clock */
 265 +       ret = ltq_i2c_hw_set_clock(adap);
 266 +       if (ret != 0) {
 267 +               dev_warn(priv->dev, "invalid clock settings\n");
 268 +               return ret;
 269 +       }
 270 +
 271 +       /* configure fifo */
 272 +       i2c_w32(I2C_FIFO_CFG_TXFC | /* tx fifo as flow controller */
 273 +               I2C_FIFO_CFG_RXFC | /* rx fifo as flow controller */
 274 +               I2C_FIFO_CFG_TXFA_TXFA2 | /* tx fifo 4-byte aligned */
 275 +               I2C_FIFO_CFG_RXFA_RXFA2 | /* rx fifo 4-byte aligned */
 276 +               I2C_FIFO_CFG_TXBS_TXBS0 | /* tx fifo burst size is 1 word */
 277 +               I2C_FIFO_CFG_RXBS_RXBS0,  /* rx fifo burst size is 1 word */
 278 +               fifo_cfg);
 279 +
 280 +       /* configure address */
 281 +       i2c_w32(I2C_ADDR_CFG_SOPE_EN |  /* generate stop when no more data in
 282 +                                          the fifo */
 283 +               I2C_ADDR_CFG_SONA_EN |  /* generate stop when NA received */
 284 +               I2C_ADDR_CFG_MnS_EN |   /* we are master device */
 285 +               0,                      /* our slave address (not used!) */
 286 +               addr_cfg);
 287 +
 288 +       /* enable bus */
 289 +       i2c_w32_mask(0, I2C_RUN_CTRL_RUN_EN, run_ctrl);
 290 +
 291 +       return 0;
 292 +}
 293 +
 294 +static int ltq_i2c_wait_bus_not_busy(struct ltq_i2c *priv)
 295 +{
 296 +       unsigned long timeout;
 297 +
 298 +       timeout = jiffies + msecs_to_jiffies(LTQ_I2C_BUSY_TIMEOUT);
 299 +
 300 +       do {
 301 +               u32 stat = i2c_r32(bus_stat);
 302 +
 303 +               if ((stat & I2C_BUS_STAT_BS_MASK) == I2C_BUS_STAT_BS_FREE)
 304 +                       return 0;
 305 +
 306 +               cond_resched();
 307 +       } while (!time_after_eq(jiffies, timeout));
 308 +
 309 +       dev_err(priv->dev, "timeout waiting for bus ready\n");
 310 +       return -ETIMEDOUT;
 311 +}
 312 +
 313 +static void ltq_i2c_tx(struct ltq_i2c *priv, int last)
 314 +{
 315 +       if (priv->msg_buf_len && priv->msg_buf) {
 316 +               i2c_w32(*priv->msg_buf, txd);
 317 +
 318 +               if (--priv->msg_buf_len)
 319 +                       priv->msg_buf++;
 320 +               else
 321 +                       priv->msg_buf = NULL;
 322 +       } else {
 323 +               last = 1;
 324 +       }
 325 +
 326 +       if (last)
 327 +               disable_burst_irq(priv);
 328 +}
 329 +
 330 +static void ltq_i2c_rx(struct ltq_i2c *priv, int last)
 331 +{
 332 +       u32 fifo_stat, timeout;
 333 +       if (priv->msg_buf_len && priv->msg_buf) {
 334 +               timeout = 5000000;
 335 +               do {
 336 +                       fifo_stat = i2c_r32(ffs_stat);
 337 +               } while (!fifo_stat && --timeout);
 338 +               if (!timeout) {
 339 +                       last = 1;
 340 +                       pr_debug("\nrx timeout\n");
 341 +                       goto err;
 342 +               }
 343 +               while (fifo_stat) {
 344 +                       *priv->msg_buf = i2c_r32(rxd);
 345 +                       if (--priv->msg_buf_len) {
 346 +                               priv->msg_buf++;
 347 +                       } else {
 348 +                               priv->msg_buf = NULL;
 349 +                               last = 1;
 350 +                               break;
 351 +                       }
 352 +                       /*
 353 +                        * do not read more than burst size, otherwise no "last
 354 +                        * burst" is generated and the transaction is blocked!
 355 +                        */
 356 +                       fifo_stat = 0;
 357 +               }
 358 +       } else {
 359 +               last = 1;
 360 +       }
 361 +err:
 362 +       if (last) {
 363 +               disable_burst_irq(priv);
 364 +
 365 +               if (priv->status == STATUS_READ_END) {
 366 +                       /*
 367 +                        * do the STATUS_STOP and complete() here, as sometimes
 368 +                        * the tx_end is already seen before this is finished
 369 +                        */
 370 +                       priv->status = STATUS_STOP;
 371 +                       complete(&priv->cmd_complete);
 372 +               } else {
 373 +                       i2c_w32(I2C_ENDD_CTRL_SETEND, endd_ctrl);
 374 +                       priv->status = STATUS_READ_END;
 375 +               }
 376 +       }
 377 +}
 378 +
 379 +static void ltq_i2c_xfer_init(struct ltq_i2c *priv)
 380 +{
 381 +       /* enable interrupts */
 382 +       i2c_w32(LTQ_I2C_IMSC_DEFAULT_MASK, imsc);
 383 +
 384 +       /* trigger transfer of first msg */
 385 +       ltq_i2c_set_tx_len(priv);
 386 +}
 387 +
 388 +static void dump_msgs(struct i2c_msg msgs[], int num, int rx)
 389 +{
 390 +#if defined(DEBUG)
 391 +       int i, j;
 392 +       pr_debug("Messages %d %s\n", num, rx ? "out" : "in");
 393 +       for (i = 0; i < num; i++) {
 394 +               pr_debug("%2d %cX Msg(%d) addr=0x%X: ", i,
 395 +                       (msgs[i].flags & I2C_M_RD) ? 'R' : 'T',
 396 +                       msgs[i].len, msgs[i].addr);
 397 +               if (!(msgs[i].flags & I2C_M_RD) || rx) {
 398 +                       for (j = 0; j < msgs[i].len; j++)
 399 +                               pr_debug("%02X ", msgs[i].buf[j]);
 400 +               }
 401 +               pr_debug("\n");
 402 +       }
 403 +#endif
 404 +}
 405 +
 406 +static void ltq_i2c_release_bus(struct ltq_i2c *priv)
 407 +{
 408 +       if ((i2c_r32(bus_stat) & I2C_BUS_STAT_BS_MASK) == I2C_BUS_STAT_BS_BM)
 409 +               i2c_w32(I2C_ENDD_CTRL_SETEND, endd_ctrl);
 410 +}
 411 +
 412 +static int ltq_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 413 +                          int num)
 414 +{
 415 +       struct ltq_i2c *priv = i2c_get_adapdata(adap);
 416 +       int ret;
 417 +
 418 +       dev_dbg(priv->dev, "xfer %u messages\n", num);
 419 +       dump_msgs(msgs, num, 0);
 420 +
 421 +       mutex_lock(&priv->mutex);
 422 +
 423 +       init_completion(&priv->cmd_complete);
 424 +       priv->current_msg = msgs;
 425 +       priv->msgs_num = num;
 426 +       priv->msg_err = 0;
 427 +       priv->status = STATUS_IDLE;
 428 +
 429 +       /* wait for the bus to become ready */
 430 +       ret = ltq_i2c_wait_bus_not_busy(priv);
 431 +       if (ret)
 432 +               goto done;
 433 +
 434 +       while (priv->msgs_num) {
 435 +               /* start the transfers */
 436 +               ltq_i2c_xfer_init(priv);
 437 +
 438 +               /* wait for transfers to complete */
 439 +               ret = wait_for_completion_interruptible_timeout(
 440 +                       &priv->cmd_complete, LTQ_I2C_XFER_TIMEOUT);
 441 +               if (ret == 0) {
 442 +                       dev_err(priv->dev, "controller timed out\n");
 443 +                       ltq_i2c_hw_init(adap);
 444 +                       ret = -ETIMEDOUT;
 445 +                       goto done;
 446 +               } else if (ret < 0)
 447 +                       goto done;
 448 +
 449 +               if (priv->msg_err) {
 450 +                       if (priv->msg_err & LTQ_I2C_NACK)
 451 +                               ret = -ENXIO;
 452 +                       else
 453 +                               ret = -EREMOTEIO;
 454 +                       goto done;
 455 +               }
 456 +               if (--priv->msgs_num)
 457 +                       priv->current_msg++;
 458 +       }
 459 +       /* no error? */
 460 +       ret = num;
 461 +
 462 +done:
 463 +       ltq_i2c_release_bus(priv);
 464 +
 465 +       mutex_unlock(&priv->mutex);
 466 +
 467 +       if (ret >= 0)
 468 +               dump_msgs(msgs, num, 1);
 469 +
 470 +       pr_debug("XFER ret %d\n", ret);
 471 +       return ret;
 472 +}
 473 +
 474 +static irqreturn_t ltq_i2c_isr_burst(int irq, void *dev_id)
 475 +{
 476 +       struct ltq_i2c *priv = dev_id;
 477 +       struct i2c_msg *msg = priv->current_msg;
 478 +       int last = (irq == priv->irq_lb);
 479 +
 480 +       if (last)
 481 +               pr_debug("LB ");
 482 +       else
 483 +               pr_debug("B ");
 484 +
 485 +       if (msg->flags & I2C_M_RD) {
 486 +               switch (priv->status) {
 487 +               case STATUS_ADDR:
 488 +                       pr_debug("X");
 489 +                       prepare_msg_send_addr(priv);
 490 +                       disable_burst_irq(priv);
 491 +                       break;
 492 +               case STATUS_READ:
 493 +               case STATUS_READ_END:
 494 +                       pr_debug("R");
 495 +                       ltq_i2c_rx(priv, last);
 496 +                       break;
 497 +               default:
 498 +                       disable_burst_irq(priv);
 499 +                       pr_warn("Status R %d\n", priv->status);
 500 +                       break;
 501 +               }
 502 +       } else {
 503 +               switch (priv->status) {
 504 +               case STATUS_ADDR:
 505 +                       pr_debug("x");
 506 +                       prepare_msg_send_addr(priv);
 507 +                       break;
 508 +               case STATUS_WRITE:
 509 +                       pr_debug("w");
 510 +                       ltq_i2c_tx(priv, last);
 511 +                       break;
 512 +               default:
 513 +                       disable_burst_irq(priv);
 514 +                       pr_warn("Status W %d\n", priv->status);
 515 +                       break;
 516 +               }
 517 +       }
 518 +
 519 +       i2c_w32(I2C_ICR_BREQ_INT_CLR | I2C_ICR_LBREQ_INT_CLR, icr);
 520 +       return IRQ_HANDLED;
 521 +}
 522 +
 523 +static void ltq_i2c_isr_prot(struct ltq_i2c *priv)
 524 +{
 525 +       u32 i_pro = i2c_r32(p_irqss);
 526 +
 527 +       pr_debug("i2c-p");
 528 +
 529 +       /* not acknowledge */
 530 +       if (i_pro & I2C_P_IRQSS_NACK) {
 531 +               priv->msg_err |= LTQ_I2C_NACK;
 532 +               pr_debug(" nack");
 533 +       }
 534 +
 535 +       /* arbitration lost */
 536 +       if (i_pro & I2C_P_IRQSS_AL) {
 537 +               priv->msg_err |= LTQ_I2C_ARB_LOST;
 538 +               pr_debug(" arb-lost");
 539 +       }
 540 +       /* tx -> rx switch */
 541 +       if (i_pro & I2C_P_IRQSS_RX)
 542 +               pr_debug(" rx");
 543 +
 544 +       /* tx end */
 545 +       if (i_pro & I2C_P_IRQSS_TX_END)
 546 +               pr_debug(" txend");
 547 +       pr_debug("\n");
 548 +
 549 +       if (!priv->msg_err) {
 550 +               /* tx -> rx switch */
 551 +               if (i_pro & I2C_P_IRQSS_RX) {
 552 +                       priv->status = STATUS_READ;
 553 +                       enable_burst_irq(priv);
 554 +               }
 555 +               if (i_pro & I2C_P_IRQSS_TX_END) {
 556 +                       if (priv->status == STATUS_READ)
 557 +                               priv->status = STATUS_READ_END;
 558 +                       else {
 559 +                               disable_burst_irq(priv);
 560 +                               priv->status = STATUS_STOP;
 561 +                       }
 562 +               }
 563 +       }
 564 +
 565 +       i2c_w32(i_pro, p_irqsc);
 566 +}
 567 +
 568 +static irqreturn_t ltq_i2c_isr(int irq, void *dev_id)
 569 +{
 570 +       u32 i_raw, i_err = 0;
 571 +       struct ltq_i2c *priv = dev_id;
 572 +
 573 +       i_raw = i2c_r32(mis);
 574 +       pr_debug("i_raw 0x%08X\n", i_raw);
 575 +
 576 +       /* error interrupt */
 577 +       if (i_raw & I2C_RIS_I2C_ERR_INT_INTOCC) {
 578 +               i_err = i2c_r32(err_irqss);
 579 +               pr_debug("i_err 0x%08X bus_stat 0x%04X\n",
 580 +                       i_err, i2c_r32(bus_stat));
 581 +
 582 +               /* tx fifo overflow (8) */
 583 +               if (i_err & I2C_ERR_IRQSS_TXF_OFL)
 584 +                       priv->msg_err |= LTQ_I2C_TX_OFL;
 585 +
 586 +               /* tx fifo underflow (4) */
 587 +               if (i_err & I2C_ERR_IRQSS_TXF_UFL)
 588 +                       priv->msg_err |= LTQ_I2C_TX_UFL;
 589 +
 590 +               /* rx fifo overflow (2) */
 591 +               if (i_err & I2C_ERR_IRQSS_RXF_OFL)
 592 +                       priv->msg_err |= LTQ_I2C_RX_OFL;
 593 +
 594 +               /* rx fifo underflow (1) */
 595 +               if (i_err & I2C_ERR_IRQSS_RXF_UFL)
 596 +                       priv->msg_err |= LTQ_I2C_RX_UFL;
 597 +
 598 +               i2c_w32(i_err, err_irqsc);
 599 +       }
 600 +
 601 +       /* protocol interrupt */
 602 +       if (i_raw & I2C_RIS_I2C_P_INT_INTOCC)
 603 +               ltq_i2c_isr_prot(priv);
 604 +
 605 +       if ((priv->msg_err) || (priv->status == STATUS_STOP))
 606 +               complete(&priv->cmd_complete);
 607 +
 608 +       return IRQ_HANDLED;
 609 +}
 610 +
 611 +static u32 ltq_i2c_functionality(struct i2c_adapter *adap)
 612 +{
 613 +       return  I2C_FUNC_I2C |
 614 +               I2C_FUNC_10BIT_ADDR |
 615 +               I2C_FUNC_SMBUS_EMUL;
 616 +}
 617 +
 618 +static struct i2c_algorithm ltq_i2c_algorithm = {
 619 +       .master_xfer    = ltq_i2c_xfer,
 620 +       .functionality  = ltq_i2c_functionality,
 621 +};
 622 +
 623 +static int ltq_i2c_probe(struct platform_device *pdev)
 624 +{
 625 +       struct device_node *node = pdev->dev.of_node;
 626 +       struct ltq_i2c *priv;
 627 +       struct i2c_adapter *adap;
 628 +       struct resource *mmres, irqres[4];
 629 +       int ret = 0;
 630 +
 631 +       dev_dbg(&pdev->dev, "probing\n");
 632 +
 633 +       mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 634 +       ret = of_irq_to_resource_table(node, irqres, 4);
 635 +       if (!mmres || (ret != 4)) {
 636 +               dev_err(&pdev->dev, "no resources\n");
 637 +               return -ENODEV;
 638 +       }
 639 +
 640 +       /* allocate private data */
 641 +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 642 +       if (!priv) {
 643 +               dev_err(&pdev->dev, "can't allocate private data\n");
 644 +               return -ENOMEM;
 645 +       }
 646 +
 647 +       adap = &priv->adap;
 648 +       i2c_set_adapdata(adap, priv);
 649 +       adap->owner = THIS_MODULE;
 650 +       adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 651 +       strlcpy(adap->name, DRV_NAME "-adapter", sizeof(adap->name));
 652 +       adap->algo = &ltq_i2c_algorithm;
 653 +       adap->dev.parent = &pdev->dev;
 654 +       adap->dev.of_node = pdev->dev.of_node;
 655 +
 656 +       if (of_property_read_u32(node, "clock-frequency", &priv->i2c_clock)) {
 657 +               dev_warn(&pdev->dev, "No I2C speed selected, using 100kHz\n");
 658 +               priv->i2c_clock = 100000;
 659 +       }
 660 +
 661 +       init_completion(&priv->cmd_complete);
 662 +       mutex_init(&priv->mutex);
 663 +
 664 +       priv->membase = devm_ioremap_resource(&pdev->dev, mmres);
 665 +       if (IS_ERR(priv->membase))
 666 +               return PTR_ERR(priv->membase);
 667 +
 668 +       priv->dev = &pdev->dev;
 669 +       priv->irq_lb = irqres[0].start;
 670 +
 671 +       ret = devm_request_irq(&pdev->dev, irqres[0].start, ltq_i2c_isr_burst,
 672 +               0x0, "i2c lb", priv);
 673 +       if (ret) {
 674 +               dev_err(&pdev->dev, "can't get last burst IRQ %d\n",
 675 +                       irqres[0].start);
 676 +               return -ENODEV;
 677 +       }
 678 +
 679 +       ret = devm_request_irq(&pdev->dev, irqres[1].start, ltq_i2c_isr_burst,
 680 +               0x0, "i2c b", priv);
 681 +       if (ret) {
 682 +               dev_err(&pdev->dev, "can't get burst IRQ %d\n",
 683 +                       irqres[1].start);
 684 +               return -ENODEV;
 685 +       }
 686 +
 687 +       ret = devm_request_irq(&pdev->dev, irqres[2].start, ltq_i2c_isr,
 688 +               0x0, "i2c err", priv);
 689 +       if (ret) {
 690 +               dev_err(&pdev->dev, "can't get error IRQ %d\n",
 691 +                       irqres[2].start);
 692 +               return -ENODEV;
 693 +       }
 694 +
 695 +       ret = devm_request_irq(&pdev->dev, irqres[3].start, ltq_i2c_isr,
 696 +               0x0, "i2c p", priv);
 697 +       if (ret) {
 698 +               dev_err(&pdev->dev, "can't get protocol IRQ %d\n",
 699 +                       irqres[3].start);
 700 +               return -ENODEV;
 701 +       }
 702 +
 703 +       dev_dbg(&pdev->dev, "mapped io-space to %p\n", priv->membase);
 704 +       dev_dbg(&pdev->dev, "use IRQs %d, %d, %d, %d\n", irqres[0].start,
 705 +               irqres[1].start, irqres[2].start, irqres[3].start);
 706 +
 707 +       priv->clk_gate = devm_clk_get(&pdev->dev, NULL);
 708 +       if (IS_ERR(priv->clk_gate)) {
 709 +               dev_err(&pdev->dev, "failed to get i2c clk\n");
 710 +               return -ENOENT;
 711 +       }
 712 +
 713 +       /* this is a static clock, which has no refcounting */
 714 +       priv->clk_input = clk_get_fpi();
 715 +       if (IS_ERR(priv->clk_input)) {
 716 +               dev_err(&pdev->dev, "failed to get fpi clk\n");
 717 +               return -ENOENT;
 718 +       }
 719 +
 720 +       clk_activate(priv->clk_gate);
 721 +
 722 +       /* add our adapter to the i2c stack */
 723 +       ret = i2c_add_numbered_adapter(adap);
 724 +       if (ret) {
 725 +               dev_err(&pdev->dev, "can't register I2C adapter\n");
 726 +               goto out;
 727 +       }
 728 +
 729 +       platform_set_drvdata(pdev, priv);
 730 +       i2c_set_adapdata(adap, priv);
 731 +
 732 +       /* print module version information */
 733 +       dev_dbg(&pdev->dev, "module id=%u revision=%u\n",
 734 +               (i2c_r32(id) & I2C_ID_ID_MASK) >> I2C_ID_ID_OFFSET,
 735 +               (i2c_r32(id) & I2C_ID_REV_MASK) >> I2C_ID_REV_OFFSET);
 736 +
 737 +       /* initialize HW */
 738 +       ret = ltq_i2c_hw_init(adap);
 739 +       if (ret) {
 740 +               dev_err(&pdev->dev, "can't configure adapter\n");
 741 +               i2c_del_adapter(adap);
 742 +               platform_set_drvdata(pdev, NULL);
 743 +               goto out;
 744 +       } else {
 745 +               dev_info(&pdev->dev, "version %s\n", DRV_VERSION);
 746 +       }
 747 +
 748 +out:
 749 +       /* if init failed, we need to deactivate the clock gate */
 750 +       if (ret)
 751 +               clk_deactivate(priv->clk_gate);
 752 +
 753 +       return ret;
 754 +}
 755 +
 756 +static int ltq_i2c_remove(struct platform_device *pdev)
 757 +{
 758 +       struct ltq_i2c *priv = platform_get_drvdata(pdev);
 759 +
 760 +       /* disable bus */
 761 +       i2c_w32_mask(I2C_RUN_CTRL_RUN_EN, 0, run_ctrl);
 762 +
 763 +       /* power down the core */
 764 +       clk_deactivate(priv->clk_gate);
 765 +
 766 +       /* remove driver */
 767 +       i2c_del_adapter(&priv->adap);
 768 +       kfree(priv);
 769 +
 770 +       dev_dbg(&pdev->dev, "removed\n");
 771 +       platform_set_drvdata(pdev, NULL);
 772 +
 773 +       return 0;
 774 +}
 775 +static const struct of_device_id ltq_i2c_match[] = {
 776 +       { .compatible = "lantiq,lantiq-i2c" },
 777 +       {},
 778 +};
 779 +MODULE_DEVICE_TABLE(of, ltq_i2c_match);
 780 +
 781 +static struct platform_driver ltq_i2c_driver = {
 782 +       .probe  = ltq_i2c_probe,
 783 +       .remove = ltq_i2c_remove,
 784 +       .driver = {
 785 +               .name   = DRV_NAME,
 786 +               .owner  = THIS_MODULE,
 787 +               .of_match_table = ltq_i2c_match,
 788 +       },
 789 +};
 790 +
 791 +module_platform_driver(ltq_i2c_driver);
 792 +
 793 +MODULE_DESCRIPTION("Lantiq I2C bus adapter");
 794 +MODULE_AUTHOR("Thomas Langer <thomas.langer@lantiq.com>");
 795 +MODULE_ALIAS("platform:" DRV_NAME);
 796 +MODULE_LICENSE("GPL");
 797 +MODULE_VERSION(DRV_VERSION);
 798 --- /dev/null
 799 +++ b/drivers/i2c/busses/i2c-lantiq.h
 800 @@ -0,0 +1,234 @@
 801 +#ifndef I2C_LANTIQ_H
 802 +#define I2C_LANTIQ_H
 803 +
 804 +/* I2C register structure */
 805 +struct lantiq_reg_i2c {
 806 +       /* I2C Kernel Clock Control Register */
 807 +       unsigned int clc; /* 0x00000000 */
 808 +       /* Reserved */
 809 +       unsigned int res_0; /* 0x00000004 */
 810 +       /* I2C Identification Register */
 811 +       unsigned int id; /* 0x00000008 */
 812 +       /* Reserved */
 813 +       unsigned int res_1; /* 0x0000000C */
 814 +       /*
 815 +        * I2C RUN Control Register
 816 +        * This register enables and disables the I2C peripheral. Before
 817 +        * enabling, the I2C has to be configured properly. After enabling
 818 +        * no configuration is possible
 819 +        */
 820 +       unsigned int run_ctrl; /* 0x00000010 */
 821 +       /*
 822 +        * I2C End Data Control Register
 823 +        * This register is used to either turn around the data transmission
 824 +        * direction or to address another slave without sending a stop
 825 +        * condition. Also the software can stop the slave-transmitter by
 826 +        * sending a not-accolade when working as master-receiver or even
 827 +        * stop data transmission immediately when operating as
 828 +        * master-transmitter. The writing to the bits of this control
 829 +        * register is only effective when in MASTER RECEIVES BYTES, MASTER
 830 +        * TRANSMITS BYTES, MASTER RESTART or SLAVE RECEIVE BYTES state
 831 +        */
 832 +       unsigned int endd_ctrl; /* 0x00000014 */
 833 +       /*
 834 +        * I2C Fractional Divider Configuration Register
 835 +        * These register is used to program the fractional divider of the I2C
 836 +        * bus. Before the peripheral is switched on by setting the RUN-bit the
 837 +        * two (fixed) values for the two operating frequencies are programmed
 838 +        * into these (configuration) registers. The Register FDIV_HIGH_CFG has
 839 +        * the same layout as I2C_FDIV_CFG.
 840 +        */
 841 +       unsigned int fdiv_cfg; /* 0x00000018 */
 842 +       /*
 843 +        * I2C Fractional Divider (highspeed mode) Configuration Register
 844 +        * These register is used to program the fractional divider of the I2C
 845 +        * bus. Before the peripheral is switched on by setting the RUN-bit the
 846 +        * two (fixed) values for the two operating frequencies are programmed
 847 +        * into these (configuration) registers. The Register FDIV_CFG has the
 848 +        * same layout as I2C_FDIV_CFG.
 849 +        */
 850 +       unsigned int fdiv_high_cfg; /* 0x0000001C */
 851 +       /* I2C Address Configuration Register */
 852 +       unsigned int addr_cfg; /* 0x00000020 */
 853 +       /* I2C Bus Status Register
 854 +        * This register gives a status information of the I2C. This additional
 855 +        * information can be used by the software to start proper actions.
 856 +        */
 857 +       unsigned int bus_stat; /* 0x00000024 */
 858 +       /* I2C FIFO Configuration Register */
 859 +       unsigned int fifo_cfg; /* 0x00000028 */
 860 +       /* I2C Maximum Received Packet Size Register */
 861 +       unsigned int mrps_ctrl; /* 0x0000002C */
 862 +       /* I2C Received Packet Size Status Register */
 863 +       unsigned int rps_stat; /* 0x00000030 */
 864 +       /* I2C Transmit Packet Size Register */
 865 +       unsigned int tps_ctrl; /* 0x00000034 */
 866 +       /* I2C Filled FIFO Stages Status Register */
 867 +       unsigned int ffs_stat; /* 0x00000038 */
 868 +       /* Reserved */
 869 +       unsigned int res_2; /* 0x0000003C */
 870 +       /* I2C Timing Configuration Register */
 871 +       unsigned int tim_cfg; /* 0x00000040 */
 872 +       /* Reserved */
 873 +       unsigned int res_3[7]; /* 0x00000044 */
 874 +       /* I2C Error Interrupt Request Source Mask Register */
 875 +       unsigned int err_irqsm; /* 0x00000060 */
 876 +       /* I2C Error Interrupt Request Source Status Register */
 877 +       unsigned int err_irqss; /* 0x00000064 */
 878 +       /* I2C Error Interrupt Request Source Clear Register */
 879 +       unsigned int err_irqsc; /* 0x00000068 */
 880 +       /* Reserved */
 881 +       unsigned int res_4; /* 0x0000006C */
 882 +       /* I2C Protocol Interrupt Request Source Mask Register */
 883 +       unsigned int p_irqsm; /* 0x00000070 */
 884 +       /* I2C Protocol Interrupt Request Source Status Register */
 885 +       unsigned int p_irqss; /* 0x00000074 */
 886 +       /* I2C Protocol Interrupt Request Source Clear Register */
 887 +       unsigned int p_irqsc; /* 0x00000078 */
 888 +       /* Reserved */
 889 +       unsigned int res_5; /* 0x0000007C */
 890 +       /* I2C Raw Interrupt Status Register */
 891 +       unsigned int ris; /* 0x00000080 */
 892 +       /* I2C Interrupt Mask Control Register */
 893 +       unsigned int imsc; /* 0x00000084 */
 894 +       /* I2C Masked Interrupt Status Register */
 895 +       unsigned int mis; /* 0x00000088 */
 896 +       /* I2C Interrupt Clear Register */
 897 +       unsigned int icr; /* 0x0000008C */
 898 +       /* I2C Interrupt Set Register */
 899 +       unsigned int isr; /* 0x00000090 */
 900 +       /* I2C DMA Enable Register */
 901 +       unsigned int dmae; /* 0x00000094 */
 902 +       /* Reserved */
 903 +       unsigned int res_6[8154]; /* 0x00000098 */
 904 +       /* I2C Transmit Data Register */
 905 +       unsigned int txd; /* 0x00008000 */
 906 +       /* Reserved */
 907 +       unsigned int res_7[4095]; /* 0x00008004 */
 908 +       /* I2C Receive Data Register */
 909 +       unsigned int rxd; /* 0x0000C000 */
 910 +       /* Reserved */
 911 +       unsigned int res_8[4095]; /* 0x0000C004 */
 912 +};
 913 +
 914 +/*
 915 + * Clock Divider for Normal Run Mode
 916 + * Max 8-bit divider value. IF RMC is 0 the module is disabled. Note: As long
 917 + * as the new divider value RMC is not valid, the register returns 0x0000 00xx
 918 + * on reading.
 919 + */
 920 +#define I2C_CLC_RMC_MASK 0x0000FF00
 921 +/* field offset */
 922 +#define I2C_CLC_RMC_OFFSET 8
 923 +
 924 +/* Fields of "I2C Identification Register" */
 925 +/* Module ID */
 926 +#define I2C_ID_ID_MASK 0x0000FF00
 927 +/* field offset */
 928 +#define I2C_ID_ID_OFFSET 8
 929 +/* Revision */
 930 +#define I2C_ID_REV_MASK 0x000000FF
 931 +/* field offset */
 932 +#define I2C_ID_REV_OFFSET 0
 933 +
 934 +/* Fields of "I2C Interrupt Mask Control Register" */
 935 +/* Enable */
 936 +#define I2C_IMSC_BREQ_INT_EN 0x00000008
 937 +/* Enable */
 938 +#define I2C_IMSC_LBREQ_INT_EN 0x00000004
 939 +
 940 +/* Fields of "I2C Fractional Divider Configuration Register" */
 941 +/* field offset */
 942 +#define I2C_FDIV_CFG_INC_OFFSET 16
 943 +
 944 +/* Fields of "I2C Interrupt Mask Control Register" */
 945 +/* Enable */
 946 +#define I2C_IMSC_I2C_P_INT_EN 0x00000020
 947 +/* Enable */
 948 +#define I2C_IMSC_I2C_ERR_INT_EN 0x00000010
 949 +
 950 +/* Fields of "I2C Error Interrupt Request Source Status Register" */
 951 +/* TXF_OFL */
 952 +#define I2C_ERR_IRQSS_TXF_OFL 0x00000008
 953 +/* TXF_UFL */
 954 +#define I2C_ERR_IRQSS_TXF_UFL 0x00000004
 955 +/* RXF_OFL */
 956 +#define I2C_ERR_IRQSS_RXF_OFL 0x00000002
 957 +/* RXF_UFL */
 958 +#define I2C_ERR_IRQSS_RXF_UFL 0x00000001
 959 +
 960 +/* Fields of "I2C Raw Interrupt Status Register" */
 961 +/* Read: Interrupt occurred. */
 962 +#define I2C_RIS_I2C_ERR_INT_INTOCC 0x00000010
 963 +/* Read: Interrupt occurred. */
 964 +#define I2C_RIS_I2C_P_INT_INTOCC 0x00000020
 965 +
 966 +/* Fields of "I2C FIFO Configuration Register" */
 967 +/* TX FIFO Flow Control */
 968 +#define I2C_FIFO_CFG_TXFC 0x00020000
 969 +/* RX FIFO Flow Control */
 970 +#define I2C_FIFO_CFG_RXFC 0x00010000
 971 +/* Word aligned (character alignment of four characters) */
 972 +#define I2C_FIFO_CFG_TXFA_TXFA2 0x00002000
 973 +/* Word aligned (character alignment of four characters) */
 974 +#define I2C_FIFO_CFG_RXFA_RXFA2 0x00000200
 975 +/* 1 word */
 976 +#define I2C_FIFO_CFG_TXBS_TXBS0 0x00000000
 977 +
 978 +/* Fields of "I2C FIFO Configuration Register" */
 979 +/* 1 word */
 980 +#define I2C_FIFO_CFG_RXBS_RXBS0 0x00000000
 981 +/* Stop on Packet End Enable */
 982 +#define I2C_ADDR_CFG_SOPE_EN 0x00200000
 983 +/* Stop on Not Acknowledge Enable */
 984 +#define I2C_ADDR_CFG_SONA_EN 0x00100000
 985 +/* Enable */
 986 +#define I2C_ADDR_CFG_MnS_EN 0x00080000
 987 +
 988 +/* Fields of "I2C Interrupt Clear Register" */
 989 +/* Clear */
 990 +#define I2C_ICR_BREQ_INT_CLR 0x00000008
 991 +/* Clear */
 992 +#define I2C_ICR_LBREQ_INT_CLR 0x00000004
 993 +
 994 +/* Fields of "I2C Fractional Divider Configuration Register" */
 995 +/* field offset */
 996 +#define I2C_FDIV_CFG_DEC_OFFSET 0
 997 +
 998 +/* Fields of "I2C Bus Status Register" */
 999 +/* Bus Status */
1000 +#define I2C_BUS_STAT_BS_MASK 0x00000003
1001 +/* Read from I2C Bus. */
1002 +#define I2C_BUS_STAT_RNW_READ 0x00000004
1003 +/* I2C Bus is free. */
1004 +#define I2C_BUS_STAT_BS_FREE 0x00000000
1005 +/*
1006 + * The device is working as master and has claimed the control on the
1007 + * I2C-bus (busy master).
1008 + */
1009 +#define I2C_BUS_STAT_BS_BM 0x00000002
1010 +
1011 +/* Fields of "I2C RUN Control Register" */
1012 +/* Enable */
1013 +#define I2C_RUN_CTRL_RUN_EN 0x00000001
1014 +
1015 +/* Fields of "I2C End Data Control Register" */
1016 +/*
1017 + * Set End of Transmission
1018 + * Note:Do not write '1' to this bit when bus is free. This will cause an
1019 + * abort after the first byte when a new transfer is started.
1020 + */
1021 +#define I2C_ENDD_CTRL_SETEND 0x00000002
1022 +
1023 +/* Fields of "I2C Protocol Interrupt Request Source Status Register" */
1024 +/* NACK */
1025 +#define I2C_P_IRQSS_NACK 0x00000010
1026 +/* AL */
1027 +#define I2C_P_IRQSS_AL 0x00000008
1028 +/* RX */
1029 +#define I2C_P_IRQSS_RX 0x00000040
1030 +/* TX_END */
1031 +#define I2C_P_IRQSS_TX_END 0x00000020
1032 +
1033 +
1034 +#endif /* I2C_LANTIQ_H */