drivers/i2c/busses/i2c-designware-platdrv.c

   1 /*
   2  * Synopsys DesignWare I2C adapter driver.
   3  *
   4  * Based on the TI DAVINCI I2C adapter driver.
   5  *
   6  * Copyright (C) 2006 Texas Instruments.
   7  * Copyright (C) 2007 MontaVista Software Inc.
   8  * Copyright (C) 2009 Provigent Ltd.
   9  *
  10  * ----------------------------------------------------------------------------
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  * ----------------------------------------------------------------------------
  22  *
  23  */
  24 #include <linux/acpi.h>
  25 #include <linux/clk-provider.h>
  26 #include <linux/clk.h>
  27 #include <linux/delay.h>
  28 #include <linux/dmi.h>
  29 #include <linux/err.h>
  30 #include <linux/errno.h>
  31 #include <linux/i2c.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/io.h>
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/of.h>
  37 #include <linux/platform_data/i2c-designware.h>
  38 #include <linux/platform_device.h>
  39 #include <linux/pm.h>
  40 #include <linux/pm_runtime.h>
  41 #include <linux/property.h>
  42 #include <linux/reset.h>
  43 #include <linux/sched.h>
  44 #include <linux/slab.h>
  45
  46 #include "i2c-designware-core.h"
  47
  48 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  49 {
  50         return clk_get_rate(dev->clk)/1000;
  51 }
  52
  53 #ifdef CONFIG_ACPI
  54 /*
  55  * The HCNT/LCNT information coming from ACPI should be the most accurate
  56  * for given platform. However, some systems get it wrong. On such systems
  57  * we get better results by calculating those based on the input clock.
  58  */
  59 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
  60         {
  61                 .ident = "Dell Inspiron 7348",
  62                 .matches = {
  63                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  64                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
  65                 },
  66         },
  67         { }
  68 };
  69
  70 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  71                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  72 {
  73         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  74         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  75         union acpi_object *obj;
  76
  77         if (dmi_check_system(dw_i2c_no_acpi_params))
  78                 return;
  79
  80         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  81                 return;
  82
  83         obj = (union acpi_object *)buf.pointer;
  84         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  85                 const union acpi_object *objs = obj->package.elements;
  86
  87                 *hcnt = (u16)objs[0].integer.value;
  88                 *lcnt = (u16)objs[1].integer.value;
  89                 *sda_hold = (u32)objs[2].integer.value;
  90         }
  91
  92         kfree(buf.pointer);
  93 }
  94
  95 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  96 {
  97         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  98         u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
  99         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 100         const struct acpi_device_id *id;
 101         struct acpi_device *adev;
 102         const char *uid;
 103
 104         dev->adapter.nr = -1;
 105         dev->tx_fifo_depth = 32;
 106         dev->rx_fifo_depth = 32;
 107
 108         /*
 109          * Try to get SDA hold time and *CNT values from an ACPI method for
 110          * selected speed modes.
 111          */
 112         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
 113         dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
 114         dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
 115         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
 116
 117         switch (dev->clk_freq) {
 118         case 100000:
 119                 dev->sda_hold_time = ss_ht;
 120                 break;
 121         case 1000000:
 122                 dev->sda_hold_time = fp_ht;
 123                 break;
 124         case 3400000:
 125                 dev->sda_hold_time = hs_ht;
 126                 break;
 127         case 400000:
 128         default:
 129                 dev->sda_hold_time = fs_ht;
 130                 break;
 131         }
 132
 133         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 134         if (id && id->driver_data)
 135                 dev->flags |= (u32)id->driver_data;
 136
 137         if (acpi_bus_get_device(handle, &adev))
 138                 return -ENODEV;
 139
 140         /*
 141          * Cherrytrail I2C7 gets used for the PMIC which gets accessed
 142          * through ACPI opregions during late suspend / early resume
 143          * disable pm for it.
 144          */
 145         uid = adev->pnp.unique_id;
 146         if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
 147                 dev->pm_disabled = true;
 148
 149         return 0;
 150 }
 151
 152 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 153         { "INT33C2", 0 },
 154         { "INT33C3", 0 },
 155         { "INT3432", 0 },
 156         { "INT3433", 0 },
 157         { "80860F41", 0 },
 158         { "808622C1", MODEL_CHERRYTRAIL },
 159         { "AMD0010", ACCESS_INTR_MASK },
 160         { "AMDI0010", ACCESS_INTR_MASK },
 161         { "AMDI0510", 0 },
 162         { "APMC0D0F", 0 },
 163         { "HISI02A1", 0 },
 164         { "HISI02A2", 0 },
 165         { }
 166 };
 167 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 168 #else
 169 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 170 {
 171         return -ENODEV;
 172 }
 173 #endif
 174
 175 static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
 176 {
 177         dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
 178
 179         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 180                           DW_IC_CON_RESTART_EN;
 181
 182         dev->mode = DW_IC_MASTER;
 183
 184         switch (dev->clk_freq) {
 185         case 100000:
 186                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
 187                 break;
 188         case 3400000:
 189                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
 190                 break;
 191         default:
 192                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
 193         }
 194 }
 195
 196 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
 197 {
 198         dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
 199
 200         dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
 201                          DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
 202
 203         dev->mode = DW_IC_SLAVE;
 204 }
 205
 206 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 207 {
 208         if (IS_ERR(i_dev->clk))
 209                 return PTR_ERR(i_dev->clk);
 210
 211         if (prepare)
 212                 return clk_prepare_enable(i_dev->clk);
 213
 214         clk_disable_unprepare(i_dev->clk);
 215         return 0;
 216 }
 217
 218 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 219 {
 220         u32 param, tx_fifo_depth, rx_fifo_depth;
 221
 222         /*
 223          * Try to detect the FIFO depth if not set by interface driver,
 224          * the depth could be from 2 to 256 from HW spec.
 225          */
 226         param = i2c_dw_read_comp_param(dev);
 227         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 228         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 229         if (!dev->tx_fifo_depth) {
 230                 dev->tx_fifo_depth = tx_fifo_depth;
 231                 dev->rx_fifo_depth = rx_fifo_depth;
 232                 dev->adapter.nr = id;
 233         } else if (tx_fifo_depth >= 2) {
 234                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 235                                 tx_fifo_depth);
 236                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 237                                 rx_fifo_depth);
 238         }
 239 }
 240
 241 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
 242 {
 243         pm_runtime_disable(dev->dev);
 244
 245         if (dev->pm_disabled)
 246                 pm_runtime_put_noidle(dev->dev);
 247 }
 248
 249 static int dw_i2c_plat_probe(struct platform_device *pdev)
 250 {
 251         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 252         struct i2c_adapter *adap;
 253         struct dw_i2c_dev *dev;
 254         u32 acpi_speed, ht = 0;
 255         struct resource *mem;
 256         int i, irq, ret;
 257         static const int supported_speeds[] = {
 258                 0, 100000, 400000, 1000000, 3400000
 259         };
 260
 261         irq = platform_get_irq(pdev, 0);
 262         if (irq < 0)
 263                 return irq;
 264
 265         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 266         if (!dev)
 267                 return -ENOMEM;
 268
 269         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 270         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 271         if (IS_ERR(dev->base))
 272                 return PTR_ERR(dev->base);
 273
 274         dev->dev = &pdev->dev;
 275         dev->irq = irq;
 276         platform_set_drvdata(pdev, dev);
 277
 278         dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 279         if (IS_ERR(dev->rst)) {
 280                 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
 281                         return -EPROBE_DEFER;
 282         } else {
 283                 reset_control_deassert(dev->rst);
 284         }
 285
 286         if (pdata) {
 287                 dev->clk_freq = pdata->i2c_scl_freq;
 288         } else {
 289                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 290                                          &ht);
 291                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 292                                          &dev->sda_falling_time);
 293                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 294                                          &dev->scl_falling_time);
 295                 device_property_read_u32(&pdev->dev, "clock-frequency",
 296                                          &dev->clk_freq);
 297         }
 298
 299         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 300         /*
 301          * Some DSTDs use a non standard speed, round down to the lowest
 302          * standard speed.
 303          */
 304         for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
 305                 if (acpi_speed < supported_speeds[i])
 306                         break;
 307         }
 308         acpi_speed = supported_speeds[i - 1];
 309
 310         /*
 311          * Find bus speed from the "clock-frequency" device property, ACPI
 312          * or by using fast mode if neither is set.
 313          */
 314         if (acpi_speed && dev->clk_freq)
 315                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
 316         else if (acpi_speed || dev->clk_freq)
 317                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
 318         else
 319                 dev->clk_freq = 400000;
 320
 321         if (has_acpi_companion(&pdev->dev))
 322                 dw_i2c_acpi_configure(pdev);
 323
 324         /*
 325          * Only standard mode at 100kHz, fast mode at 400kHz,
 326          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 327          */
 328         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 329             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 330                 dev_err(&pdev->dev,
 331                         "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
 332                         dev->clk_freq);
 333                 ret = -EINVAL;
 334                 goto exit_reset;
 335         }
 336
 337         ret = i2c_dw_probe_lock_support(dev);
 338         if (ret)
 339                 goto exit_reset;
 340
 341         if (i2c_detect_slave_mode(&pdev->dev))
 342                 i2c_dw_configure_slave(dev);
 343         else
 344                 i2c_dw_configure_master(dev);
 345
 346         dev->clk = devm_clk_get(&pdev->dev, NULL);
 347         if (!i2c_dw_plat_prepare_clk(dev, true)) {
 348                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 349
 350                 if (!dev->sda_hold_time && ht)
 351                         dev->sda_hold_time = div_u64(
 352                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 353                                 1000000);
 354         }
 355
 356         dw_i2c_set_fifo_size(dev, pdev->id);
 357
 358         adap = &dev->adapter;
 359         adap->owner = THIS_MODULE;
 360         adap->class = I2C_CLASS_DEPRECATED;
 361         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 362         adap->dev.of_node = pdev->dev.of_node;
 363
 364         /* The code below assumes runtime PM to be disabled. */
 365         WARN_ON(pm_runtime_enabled(&pdev->dev));
 366
 367         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 368         pm_runtime_use_autosuspend(&pdev->dev);
 369         pm_runtime_set_active(&pdev->dev);
 370
 371         if (dev->pm_disabled)
 372                 pm_runtime_get_noresume(&pdev->dev);
 373
 374         pm_runtime_enable(&pdev->dev);
 375
 376         if (dev->mode == DW_IC_SLAVE)
 377                 ret = i2c_dw_probe_slave(dev);
 378         else
 379                 ret = i2c_dw_probe(dev);
 380
 381         if (ret)
 382                 goto exit_probe;
 383
 384         return ret;
 385
 386 exit_probe:
 387         dw_i2c_plat_pm_cleanup(dev);
 388 exit_reset:
 389         if (!IS_ERR_OR_NULL(dev->rst))
 390                 reset_control_assert(dev->rst);
 391         return ret;
 392 }
 393
 394 static int dw_i2c_plat_remove(struct platform_device *pdev)
 395 {
 396         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 397
 398         pm_runtime_get_sync(&pdev->dev);
 399
 400         i2c_del_adapter(&dev->adapter);
 401
 402         dev->disable(dev);
 403
 404         pm_runtime_dont_use_autosuspend(&pdev->dev);
 405         pm_runtime_put_sync(&pdev->dev);
 406         dw_i2c_plat_pm_cleanup(dev);
 407
 408         if (!IS_ERR_OR_NULL(dev->rst))
 409                 reset_control_assert(dev->rst);
 410
 411         i2c_dw_remove_lock_support(dev);
 412
 413         return 0;
 414 }
 415
 416 #ifdef CONFIG_OF
 417 static const struct of_device_id dw_i2c_of_match[] = {
 418         { .compatible = "snps,designware-i2c", },
 419         {},
 420 };
 421 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 422 #endif
 423
 424 #ifdef CONFIG_PM_SLEEP
 425 static int dw_i2c_plat_prepare(struct device *dev)
 426 {
 427         return pm_runtime_suspended(dev);
 428 }
 429
 430 static void dw_i2c_plat_complete(struct device *dev)
 431 {
 432         if (dev->power.direct_complete)
 433                 pm_request_resume(dev);
 434 }
 435 #else
 436 #define dw_i2c_plat_prepare     NULL
 437 #define dw_i2c_plat_complete    NULL
 438 #endif
 439
 440 #ifdef CONFIG_PM
 441 static int dw_i2c_plat_suspend(struct device *dev)
 442 {
 443         struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 444
 445         if (i_dev->suspended) {
 446                 i_dev->skip_resume = true;
 447                 return 0;
 448         }
 449
 450         i_dev->disable(i_dev);
 451         i2c_dw_plat_prepare_clk(i_dev, false);
 452
 453         i_dev->suspended = true;
 454
 455         return 0;
 456 }
 457
 458 static int dw_i2c_plat_resume(struct device *dev)
 459 {
 460         struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 461
 462         if (!i_dev->suspended)
 463                 return 0;
 464
 465         if (i_dev->skip_resume) {
 466                 i_dev->skip_resume = false;
 467                 return 0;
 468         }
 469
 470         i2c_dw_plat_prepare_clk(i_dev, true);
 471         i_dev->init(i_dev);
 472
 473         i_dev->suspended = false;
 474
 475         return 0;
 476 }
 477
 478 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 479         .prepare = dw_i2c_plat_prepare,
 480         .complete = dw_i2c_plat_complete,
 481         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 482         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 483 };
 484
 485 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 486 #else
 487 #define DW_I2C_DEV_PMOPS NULL
 488 #endif
 489
 490 /* Work with hotplug and coldplug */
 491 MODULE_ALIAS("platform:i2c_designware");
 492
 493 static struct platform_driver dw_i2c_driver = {
 494         .probe = dw_i2c_plat_probe,
 495         .remove = dw_i2c_plat_remove,
 496         .driver         = {
 497                 .name   = "i2c_designware",
 498                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 499                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 500                 .pm     = DW_I2C_DEV_PMOPS,
 501         },
 502 };
 503
 504 static int __init dw_i2c_init_driver(void)
 505 {
 506         return platform_driver_register(&dw_i2c_driver);
 507 }
 508 subsys_initcall(dw_i2c_init_driver);
 509
 510 static void __exit dw_i2c_exit_driver(void)
 511 {
 512         platform_driver_unregister(&dw_i2c_driver);
 513 }
 514 module_exit(dw_i2c_exit_driver);
 515
 516 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 517 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 518 MODULE_LICENSE("GPL");