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 #include <linux/suspend.h>
  46
  47 #include "i2c-designware-core.h"
  48
  49 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  50 {
  51         return clk_get_rate(dev->clk)/1000;
  52 }
  53
  54 #ifdef CONFIG_ACPI
  55 /*
  56  * The HCNT/LCNT information coming from ACPI should be the most accurate
  57  * for given platform. However, some systems get it wrong. On such systems
  58  * we get better results by calculating those based on the input clock.
  59  */
  60 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
  61         {
  62                 .ident = "Dell Inspiron 7348",
  63                 .matches = {
  64                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  65                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
  66                 },
  67         },
  68         { }
  69 };
  70
  71 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  72                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  73 {
  74         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  75         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  76         union acpi_object *obj;
  77
  78         if (dmi_check_system(dw_i2c_no_acpi_params))
  79                 return;
  80
  81         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  82                 return;
  83
  84         obj = (union acpi_object *)buf.pointer;
  85         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  86                 const union acpi_object *objs = obj->package.elements;
  87
  88                 *hcnt = (u16)objs[0].integer.value;
  89                 *lcnt = (u16)objs[1].integer.value;
  90                 *sda_hold = (u32)objs[2].integer.value;
  91         }
  92
  93         kfree(buf.pointer);
  94 }
  95
  96 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  97 {
  98         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  99         u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
 100         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 101         const struct acpi_device_id *id;
 102         struct acpi_device *adev;
 103         const char *uid;
 104
 105         dev->adapter.nr = -1;
 106         dev->tx_fifo_depth = 32;
 107         dev->rx_fifo_depth = 32;
 108
 109         /*
 110          * Try to get SDA hold time and *CNT values from an ACPI method for
 111          * selected speed modes.
 112          */
 113         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
 114         dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
 115         dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
 116         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
 117
 118         switch (dev->clk_freq) {
 119         case 100000:
 120                 dev->sda_hold_time = ss_ht;
 121                 break;
 122         case 1000000:
 123                 dev->sda_hold_time = fp_ht;
 124                 break;
 125         case 3400000:
 126                 dev->sda_hold_time = hs_ht;
 127                 break;
 128         case 400000:
 129         default:
 130                 dev->sda_hold_time = fs_ht;
 131                 break;
 132         }
 133
 134         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 135         if (id && id->driver_data)
 136                 dev->flags |= (u32)id->driver_data;
 137
 138         if (acpi_bus_get_device(handle, &adev))
 139                 return -ENODEV;
 140
 141         /*
 142          * Cherrytrail I2C7 gets used for the PMIC which gets accessed
 143          * through ACPI opregions during late suspend / early resume
 144          * disable pm for it.
 145          */
 146         uid = adev->pnp.unique_id;
 147         if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
 148                 dev->pm_disabled = true;
 149
 150         return 0;
 151 }
 152
 153 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 154         { "INT33C2", 0 },
 155         { "INT33C3", 0 },
 156         { "INT3432", 0 },
 157         { "INT3433", 0 },
 158         { "80860F41", 0 },
 159         { "808622C1", MODEL_CHERRYTRAIL },
 160         { "AMD0010", ACCESS_INTR_MASK },
 161         { "AMDI0010", ACCESS_INTR_MASK },
 162         { "AMDI0510", 0 },
 163         { "APMC0D0F", 0 },
 164         { "HISI02A1", 0 },
 165         { "HISI02A2", 0 },
 166         { }
 167 };
 168 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 169 #else
 170 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 171 {
 172         return -ENODEV;
 173 }
 174 #endif
 175
 176 static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
 177 {
 178         dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
 179
 180         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 181                           DW_IC_CON_RESTART_EN;
 182
 183         dev->mode = DW_IC_MASTER;
 184
 185         switch (dev->clk_freq) {
 186         case 100000:
 187                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
 188                 break;
 189         case 3400000:
 190                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
 191                 break;
 192         default:
 193                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
 194         }
 195 }
 196
 197 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
 198 {
 199         dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
 200
 201         dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
 202                          DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
 203
 204         dev->mode = DW_IC_SLAVE;
 205 }
 206
 207 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 208 {
 209         u32 param, tx_fifo_depth, rx_fifo_depth;
 210
 211         /*
 212          * Try to detect the FIFO depth if not set by interface driver,
 213          * the depth could be from 2 to 256 from HW spec.
 214          */
 215         param = i2c_dw_read_comp_param(dev);
 216         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 217         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 218         if (!dev->tx_fifo_depth) {
 219                 dev->tx_fifo_depth = tx_fifo_depth;
 220                 dev->rx_fifo_depth = rx_fifo_depth;
 221                 dev->adapter.nr = id;
 222         } else if (tx_fifo_depth >= 2) {
 223                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 224                                 tx_fifo_depth);
 225                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 226                                 rx_fifo_depth);
 227         }
 228 }
 229
 230 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
 231 {
 232         pm_runtime_disable(dev->dev);
 233
 234         if (dev->pm_disabled)
 235                 pm_runtime_put_noidle(dev->dev);
 236 }
 237
 238 static int dw_i2c_plat_probe(struct platform_device *pdev)
 239 {
 240         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 241         struct i2c_adapter *adap;
 242         struct dw_i2c_dev *dev;
 243         u32 acpi_speed, ht = 0;
 244         struct resource *mem;
 245         int i, irq, ret;
 246         static const int supported_speeds[] = {
 247                 0, 100000, 400000, 1000000, 3400000
 248         };
 249
 250         irq = platform_get_irq(pdev, 0);
 251         if (irq < 0)
 252                 return irq;
 253
 254         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 255         if (!dev)
 256                 return -ENOMEM;
 257
 258         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 259         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 260         if (IS_ERR(dev->base))
 261                 return PTR_ERR(dev->base);
 262
 263         dev->dev = &pdev->dev;
 264         dev->irq = irq;
 265         platform_set_drvdata(pdev, dev);
 266
 267         dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 268         if (IS_ERR(dev->rst)) {
 269                 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
 270                         return -EPROBE_DEFER;
 271         } else {
 272                 reset_control_deassert(dev->rst);
 273         }
 274
 275         if (pdata) {
 276                 dev->clk_freq = pdata->i2c_scl_freq;
 277         } else {
 278                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 279                                          &ht);
 280                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 281                                          &dev->sda_falling_time);
 282                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 283                                          &dev->scl_falling_time);
 284                 device_property_read_u32(&pdev->dev, "clock-frequency",
 285                                          &dev->clk_freq);
 286         }
 287
 288         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 289         /*
 290          * Some DSTDs use a non standard speed, round down to the lowest
 291          * standard speed.
 292          */
 293         for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
 294                 if (acpi_speed < supported_speeds[i])
 295                         break;
 296         }
 297         acpi_speed = supported_speeds[i - 1];
 298
 299         /*
 300          * Find bus speed from the "clock-frequency" device property, ACPI
 301          * or by using fast mode if neither is set.
 302          */
 303         if (acpi_speed && dev->clk_freq)
 304                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
 305         else if (acpi_speed || dev->clk_freq)
 306                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
 307         else
 308                 dev->clk_freq = 400000;
 309
 310         if (has_acpi_companion(&pdev->dev))
 311                 dw_i2c_acpi_configure(pdev);
 312
 313         /*
 314          * Only standard mode at 100kHz, fast mode at 400kHz,
 315          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 316          */
 317         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 318             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 319                 dev_err(&pdev->dev,
 320                         "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
 321                         dev->clk_freq);
 322                 ret = -EINVAL;
 323                 goto exit_reset;
 324         }
 325
 326         ret = i2c_dw_probe_lock_support(dev);
 327         if (ret)
 328                 goto exit_reset;
 329
 330         if (i2c_detect_slave_mode(&pdev->dev))
 331                 i2c_dw_configure_slave(dev);
 332         else
 333                 i2c_dw_configure_master(dev);
 334
 335         dev->clk = devm_clk_get(&pdev->dev, NULL);
 336         if (!i2c_dw_prepare_clk(dev, true)) {
 337                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 338
 339                 if (!dev->sda_hold_time && ht)
 340                         dev->sda_hold_time = div_u64(
 341                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 342                                 1000000);
 343         }
 344
 345         dw_i2c_set_fifo_size(dev, pdev->id);
 346
 347         adap = &dev->adapter;
 348         adap->owner = THIS_MODULE;
 349         adap->class = I2C_CLASS_DEPRECATED;
 350         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 351         adap->dev.of_node = pdev->dev.of_node;
 352
 353         dev_pm_set_driver_flags(&pdev->dev,
 354                                 DPM_FLAG_SMART_PREPARE |
 355                                 DPM_FLAG_SMART_SUSPEND |
 356                                 DPM_FLAG_LEAVE_SUSPENDED);
 357
 358         /* The code below assumes runtime PM to be disabled. */
 359         WARN_ON(pm_runtime_enabled(&pdev->dev));
 360
 361         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 362         pm_runtime_use_autosuspend(&pdev->dev);
 363         pm_runtime_set_active(&pdev->dev);
 364
 365         if (dev->pm_disabled)
 366                 pm_runtime_get_noresume(&pdev->dev);
 367
 368         pm_runtime_enable(&pdev->dev);
 369
 370         if (dev->mode == DW_IC_SLAVE)
 371                 ret = i2c_dw_probe_slave(dev);
 372         else
 373                 ret = i2c_dw_probe(dev);
 374
 375         if (ret)
 376                 goto exit_probe;
 377
 378         return ret;
 379
 380 exit_probe:
 381         dw_i2c_plat_pm_cleanup(dev);
 382 exit_reset:
 383         if (!IS_ERR_OR_NULL(dev->rst))
 384                 reset_control_assert(dev->rst);
 385         return ret;
 386 }
 387
 388 static int dw_i2c_plat_remove(struct platform_device *pdev)
 389 {
 390         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 391
 392         pm_runtime_get_sync(&pdev->dev);
 393
 394         i2c_del_adapter(&dev->adapter);
 395
 396         dev->disable(dev);
 397
 398         pm_runtime_dont_use_autosuspend(&pdev->dev);
 399         pm_runtime_put_sync(&pdev->dev);
 400         dw_i2c_plat_pm_cleanup(dev);
 401
 402         if (!IS_ERR_OR_NULL(dev->rst))
 403                 reset_control_assert(dev->rst);
 404
 405         i2c_dw_remove_lock_support(dev);
 406
 407         return 0;
 408 }
 409
 410 #ifdef CONFIG_OF
 411 static const struct of_device_id dw_i2c_of_match[] = {
 412         { .compatible = "snps,designware-i2c", },
 413         {},
 414 };
 415 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 416 #endif
 417
 418 #ifdef CONFIG_PM_SLEEP
 419 static int dw_i2c_plat_prepare(struct device *dev)
 420 {
 421         /*
 422          * If the ACPI companion device object is present for this device, it
 423          * may be accessed during suspend and resume of other devices via I2C
 424          * operation regions, so tell the PM core and middle layers to avoid
 425          * skipping system suspend/resume callbacks for it in that case.
 426          */
 427         return !has_acpi_companion(dev);
 428 }
 429
 430 static void dw_i2c_plat_complete(struct device *dev)
 431 {
 432         /*
 433          * The device can only be in runtime suspend at this point if it has not
 434          * been resumed throughout the ending system suspend/resume cycle, so if
 435          * the platform firmware might mess up with it, request the runtime PM
 436          * framework to resume it.
 437          */
 438         if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
 439                 pm_request_resume(dev);
 440 }
 441 #else
 442 #define dw_i2c_plat_prepare     NULL
 443 #define dw_i2c_plat_complete    NULL
 444 #endif
 445
 446 #ifdef CONFIG_PM
 447 static int dw_i2c_plat_suspend(struct device *dev)
 448 {
 449         struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 450
 451         i_dev->disable(i_dev);
 452         i2c_dw_prepare_clk(i_dev, false);
 453
 454         return 0;
 455 }
 456
 457 static int dw_i2c_plat_resume(struct device *dev)
 458 {
 459         struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 460
 461         i2c_dw_prepare_clk(i_dev, true);
 462         i_dev->init(i_dev);
 463
 464         return 0;
 465 }
 466
 467 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 468         .prepare = dw_i2c_plat_prepare,
 469         .complete = dw_i2c_plat_complete,
 470         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 471         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 472 };
 473
 474 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 475 #else
 476 #define DW_I2C_DEV_PMOPS NULL
 477 #endif
 478
 479 /* Work with hotplug and coldplug */
 480 MODULE_ALIAS("platform:i2c_designware");
 481
 482 static struct platform_driver dw_i2c_driver = {
 483         .probe = dw_i2c_plat_probe,
 484         .remove = dw_i2c_plat_remove,
 485         .driver         = {
 486                 .name   = "i2c_designware",
 487                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 488                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 489                 .pm     = DW_I2C_DEV_PMOPS,
 490         },
 491 };
 492
 493 static int __init dw_i2c_init_driver(void)
 494 {
 495         return platform_driver_register(&dw_i2c_driver);
 496 }
 497 subsys_initcall(dw_i2c_init_driver);
 498
 499 static void __exit dw_i2c_exit_driver(void)
 500 {
 501         platform_driver_unregister(&dw_i2c_driver);
 502 }
 503 module_exit(dw_i2c_exit_driver);
 504
 505 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 506 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 507 MODULE_LICENSE("GPL");