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         switch (dev->clk_freq) {
 206         case 100000:
 207                 dev->slave_cfg |= DW_IC_CON_SPEED_STD;
 208                 break;
 209         case 3400000:
 210                 dev->slave_cfg |= DW_IC_CON_SPEED_HIGH;
 211                 break;
 212         default:
 213                 dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
 214         }
 215 }
 216
 217 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 218 {
 219         if (IS_ERR(i_dev->clk))
 220                 return PTR_ERR(i_dev->clk);
 221
 222         if (prepare)
 223                 return clk_prepare_enable(i_dev->clk);
 224
 225         clk_disable_unprepare(i_dev->clk);
 226         return 0;
 227 }
 228
 229 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 230 {
 231         u32 param, tx_fifo_depth, rx_fifo_depth;
 232
 233         /*
 234          * Try to detect the FIFO depth if not set by interface driver,
 235          * the depth could be from 2 to 256 from HW spec.
 236          */
 237         param = i2c_dw_read_comp_param(dev);
 238         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 239         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 240         if (!dev->tx_fifo_depth) {
 241                 dev->tx_fifo_depth = tx_fifo_depth;
 242                 dev->rx_fifo_depth = rx_fifo_depth;
 243                 dev->adapter.nr = id;
 244         } else if (tx_fifo_depth >= 2) {
 245                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 246                                 tx_fifo_depth);
 247                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 248                                 rx_fifo_depth);
 249         }
 250 }
 251
 252 static int dw_i2c_plat_probe(struct platform_device *pdev)
 253 {
 254         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 255         struct i2c_adapter *adap;
 256         struct dw_i2c_dev *dev;
 257         u32 acpi_speed, ht = 0;
 258         struct resource *mem;
 259         int i, irq, ret;
 260         const int supported_speeds[] = { 0, 100000, 400000, 1000000, 3400000 };
 261
 262         irq = platform_get_irq(pdev, 0);
 263         if (irq < 0)
 264                 return irq;
 265
 266         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 267         if (!dev)
 268                 return -ENOMEM;
 269
 270         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 271         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 272         if (IS_ERR(dev->base))
 273                 return PTR_ERR(dev->base);
 274
 275         dev->dev = &pdev->dev;
 276         dev->irq = irq;
 277         platform_set_drvdata(pdev, dev);
 278
 279         dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 280         if (IS_ERR(dev->rst)) {
 281                 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
 282                         return -EPROBE_DEFER;
 283         } else {
 284                 reset_control_deassert(dev->rst);
 285         }
 286
 287         if (pdata) {
 288                 dev->clk_freq = pdata->i2c_scl_freq;
 289         } else {
 290                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 291                                          &ht);
 292                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 293                                          &dev->sda_falling_time);
 294                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 295                                          &dev->scl_falling_time);
 296                 device_property_read_u32(&pdev->dev, "clock-frequency",
 297                                          &dev->clk_freq);
 298         }
 299
 300         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 301         /*
 302          * Some DSTDs use a non standard speed, round down to the lowest
 303          * standard speed.
 304          */
 305         for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
 306                 if (acpi_speed < supported_speeds[i])
 307                         break;
 308         }
 309         acpi_speed = supported_speeds[i - 1];
 310
 311         /*
 312          * Find bus speed from the "clock-frequency" device property, ACPI
 313          * or by using fast mode if neither is set.
 314          */
 315         if (acpi_speed && dev->clk_freq)
 316                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
 317         else if (acpi_speed || dev->clk_freq)
 318                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
 319         else
 320                 dev->clk_freq = 400000;
 321
 322         if (has_acpi_companion(&pdev->dev))
 323                 dw_i2c_acpi_configure(pdev);
 324
 325         /*
 326          * Only standard mode at 100kHz, fast mode at 400kHz,
 327          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 328          */
 329         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 330             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 331                 dev_err(&pdev->dev,
 332                         "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
 333                         dev->clk_freq);
 334                 ret = -EINVAL;
 335                 goto exit_reset;
 336         }
 337
 338         ret = i2c_dw_probe_lock_support(dev);
 339         if (ret)
 340                 goto exit_reset;
 341
 342         if (i2c_detect_slave_mode(&pdev->dev))
 343                 i2c_dw_configure_slave(dev);
 344         else
 345                 i2c_dw_configure_master(dev);
 346
 347         dev->clk = devm_clk_get(&pdev->dev, NULL);
 348         if (!i2c_dw_plat_prepare_clk(dev, true)) {
 349                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 350
 351                 if (!dev->sda_hold_time && ht)
 352                         dev->sda_hold_time = div_u64(
 353                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 354                                 1000000);
 355         }
 356
 357         dw_i2c_set_fifo_size(dev, pdev->id);
 358
 359         adap = &dev->adapter;
 360         adap->owner = THIS_MODULE;
 361         adap->class = I2C_CLASS_DEPRECATED;
 362         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 363         adap->dev.of_node = pdev->dev.of_node;
 364
 365         if (dev->pm_disabled) {
 366                 pm_runtime_forbid(&pdev->dev);
 367         } else {
 368                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 369                 pm_runtime_use_autosuspend(&pdev->dev);
 370                 pm_runtime_set_active(&pdev->dev);
 371                 pm_runtime_enable(&pdev->dev);
 372         }
 373
 374         if (dev->mode == DW_IC_SLAVE)
 375                 ret = i2c_dw_probe_slave(dev);
 376         else
 377                 ret = i2c_dw_probe(dev);
 378
 379         if (ret)
 380                 goto exit_probe;
 381
 382         return ret;
 383
 384 exit_probe:
 385         if (!dev->pm_disabled)
 386                 pm_runtime_disable(&pdev->dev);
 387 exit_reset:
 388         if (!IS_ERR_OR_NULL(dev->rst))
 389                 reset_control_assert(dev->rst);
 390         return ret;
 391 }
 392
 393 static int dw_i2c_plat_remove(struct platform_device *pdev)
 394 {
 395         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 396
 397         pm_runtime_get_sync(&pdev->dev);
 398
 399         i2c_del_adapter(&dev->adapter);
 400
 401         dev->disable(dev);
 402
 403         pm_runtime_dont_use_autosuspend(&pdev->dev);
 404         pm_runtime_put_sync(&pdev->dev);
 405         if (!dev->pm_disabled)
 406                 pm_runtime_disable(&pdev->dev);
 407         if (!IS_ERR_OR_NULL(dev->rst))
 408                 reset_control_assert(dev->rst);
 409
 410         i2c_dw_remove_lock_support(dev);
 411
 412         return 0;
 413 }
 414
 415 #ifdef CONFIG_OF
 416 static const struct of_device_id dw_i2c_of_match[] = {
 417         { .compatible = "snps,designware-i2c", },
 418         {},
 419 };
 420 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 421 #endif
 422
 423 #ifdef CONFIG_PM_SLEEP
 424 static int dw_i2c_plat_prepare(struct device *dev)
 425 {
 426         return pm_runtime_suspended(dev);
 427 }
 428
 429 static void dw_i2c_plat_complete(struct device *dev)
 430 {
 431         if (dev->power.direct_complete)
 432                 pm_request_resume(dev);
 433 }
 434 #else
 435 #define dw_i2c_plat_prepare     NULL
 436 #define dw_i2c_plat_complete    NULL
 437 #endif
 438
 439 #ifdef CONFIG_PM
 440 static int dw_i2c_plat_runtime_suspend(struct device *dev)
 441 {
 442         struct platform_device *pdev = to_platform_device(dev);
 443         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 444
 445         i_dev->disable(i_dev);
 446         i2c_dw_plat_prepare_clk(i_dev, false);
 447
 448         return 0;
 449 }
 450
 451 static int dw_i2c_plat_resume(struct device *dev)
 452 {
 453         struct platform_device *pdev = to_platform_device(dev);
 454         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 455
 456         i2c_dw_plat_prepare_clk(i_dev, true);
 457         i_dev->init(i_dev);
 458
 459         return 0;
 460 }
 461
 462 #ifdef CONFIG_PM_SLEEP
 463 static int dw_i2c_plat_suspend(struct device *dev)
 464 {
 465         pm_runtime_resume(dev);
 466         return dw_i2c_plat_runtime_suspend(dev);
 467 }
 468 #endif
 469
 470 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 471         .prepare = dw_i2c_plat_prepare,
 472         .complete = dw_i2c_plat_complete,
 473         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 474         SET_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend,
 475                            dw_i2c_plat_resume,
 476                            NULL)
 477 };
 478
 479 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 480 #else
 481 #define DW_I2C_DEV_PMOPS NULL
 482 #endif
 483
 484 /* Work with hotplug and coldplug */
 485 MODULE_ALIAS("platform:i2c_designware");
 486
 487 static struct platform_driver dw_i2c_driver = {
 488         .probe = dw_i2c_plat_probe,
 489         .remove = dw_i2c_plat_remove,
 490         .driver         = {
 491                 .name   = "i2c_designware",
 492                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 493                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 494                 .pm     = DW_I2C_DEV_PMOPS,
 495         },
 496 };
 497
 498 static int __init dw_i2c_init_driver(void)
 499 {
 500         return platform_driver_register(&dw_i2c_driver);
 501 }
 502 subsys_initcall(dw_i2c_init_driver);
 503
 504 static void __exit dw_i2c_exit_driver(void)
 505 {
 506         platform_driver_unregister(&dw_i2c_driver);
 507 }
 508 module_exit(dw_i2c_exit_driver);
 509
 510 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 511 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 512 MODULE_LICENSE("GPL");