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

   1 /*
   2  * Synopsys DesignWare I2C adapter driver (master only).
   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/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/delay.h>
  27 #include <linux/dmi.h>
  28 #include <linux/i2c.h>
  29 #include <linux/clk.h>
  30 #include <linux/clk-provider.h>
  31 #include <linux/errno.h>
  32 #include <linux/sched.h>
  33 #include <linux/err.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/of.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/pm.h>
  38 #include <linux/pm_runtime.h>
  39 #include <linux/property.h>
  40 #include <linux/io.h>
  41 #include <linux/reset.h>
  42 #include <linux/slab.h>
  43 #include <linux/acpi.h>
  44 #include <linux/platform_data/i2c-designware.h>
  45 #include "i2c-designware-core.h"
  46
  47 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  48 {
  49         return clk_get_rate(dev->clk)/1000;
  50 }
  51
  52 #ifdef CONFIG_ACPI
  53 /*
  54  * The HCNT/LCNT information coming from ACPI should be the most accurate
  55  * for given platform. However, some systems get it wrong. On such systems
  56  * we get better results by calculating those based on the input clock.
  57  */
  58 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
  59         {
  60                 .ident = "Dell Inspiron 7348",
  61                 .matches = {
  62                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  63                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
  64                 },
  65         },
  66         { }
  67 };
  68
  69 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  70                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  71 {
  72         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  73         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  74         union acpi_object *obj;
  75
  76         if (dmi_check_system(dw_i2c_no_acpi_params))
  77                 return;
  78
  79         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  80                 return;
  81
  82         obj = (union acpi_object *)buf.pointer;
  83         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  84                 const union acpi_object *objs = obj->package.elements;
  85
  86                 *hcnt = (u16)objs[0].integer.value;
  87                 *lcnt = (u16)objs[1].integer.value;
  88                 *sda_hold = (u32)objs[2].integer.value;
  89         }
  90
  91         kfree(buf.pointer);
  92 }
  93
  94 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  95 {
  96         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  97         u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
  98         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  99         const struct acpi_device_id *id;
 100         struct acpi_device *adev;
 101         const char *uid;
 102
 103         dev->adapter.nr = -1;
 104         dev->tx_fifo_depth = 32;
 105         dev->rx_fifo_depth = 32;
 106
 107         /*
 108          * Try to get SDA hold time and *CNT values from an ACPI method for
 109          * selected speed modes.
 110          */
 111         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
 112         dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
 113         dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
 114         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
 115
 116         switch (dev->clk_freq) {
 117         case 100000:
 118                 dev->sda_hold_time = ss_ht;
 119                 break;
 120         case 1000000:
 121                 dev->sda_hold_time = fp_ht;
 122                 break;
 123         case 3400000:
 124                 dev->sda_hold_time = hs_ht;
 125                 break;
 126         case 400000:
 127         default:
 128                 dev->sda_hold_time = fs_ht;
 129                 break;
 130         }
 131
 132         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 133         if (id && id->driver_data)
 134                 dev->flags |= (u32)id->driver_data;
 135
 136         if (acpi_bus_get_device(handle, &adev))
 137                 return -ENODEV;
 138
 139         /*
 140          * Cherrytrail I2C7 gets used for the PMIC which gets accessed
 141          * through ACPI opregions during late suspend / early resume
 142          * disable pm for it.
 143          */
 144         uid = adev->pnp.unique_id;
 145         if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
 146                 dev->pm_disabled = true;
 147
 148         return 0;
 149 }
 150
 151 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 152         { "INT33C2", 0 },
 153         { "INT33C3", 0 },
 154         { "INT3432", 0 },
 155         { "INT3433", 0 },
 156         { "80860F41", 0 },
 157         { "808622C1", MODEL_CHERRYTRAIL },
 158         { "AMD0010", ACCESS_INTR_MASK },
 159         { "AMDI0010", ACCESS_INTR_MASK },
 160         { "AMDI0510", 0 },
 161         { "APMC0D0F", 0 },
 162         { "HISI02A1", 0 },
 163         { "HISI02A2", 0 },
 164         { }
 165 };
 166 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 167 #else
 168 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 169 {
 170         return -ENODEV;
 171 }
 172 #endif
 173
 174 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 175 {
 176         if (IS_ERR(i_dev->clk))
 177                 return PTR_ERR(i_dev->clk);
 178
 179         if (prepare)
 180                 return clk_prepare_enable(i_dev->clk);
 181
 182         clk_disable_unprepare(i_dev->clk);
 183         return 0;
 184 }
 185
 186 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 187 {
 188         u32 param, tx_fifo_depth, rx_fifo_depth;
 189
 190         /*
 191          * Try to detect the FIFO depth if not set by interface driver,
 192          * the depth could be from 2 to 256 from HW spec.
 193          */
 194         param = i2c_dw_read_comp_param(dev);
 195         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 196         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 197         if (!dev->tx_fifo_depth) {
 198                 dev->tx_fifo_depth = tx_fifo_depth;
 199                 dev->rx_fifo_depth = rx_fifo_depth;
 200                 dev->adapter.nr = id;
 201         } else if (tx_fifo_depth >= 2) {
 202                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 203                                 tx_fifo_depth);
 204                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 205                                 rx_fifo_depth);
 206         }
 207 }
 208
 209 static int dw_i2c_plat_probe(struct platform_device *pdev)
 210 {
 211         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 212         struct dw_i2c_dev *dev;
 213         struct i2c_adapter *adap;
 214         struct resource *mem;
 215         int irq, r;
 216         u32 acpi_speed, ht = 0;
 217
 218         irq = platform_get_irq(pdev, 0);
 219         if (irq < 0)
 220                 return irq;
 221
 222         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 223         if (!dev)
 224                 return -ENOMEM;
 225
 226         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 227         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 228         if (IS_ERR(dev->base))
 229                 return PTR_ERR(dev->base);
 230
 231         dev->dev = &pdev->dev;
 232         dev->irq = irq;
 233         platform_set_drvdata(pdev, dev);
 234
 235         dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 236         if (IS_ERR(dev->rst)) {
 237                 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
 238                         return -EPROBE_DEFER;
 239         } else {
 240                 reset_control_deassert(dev->rst);
 241         }
 242
 243         if (pdata) {
 244                 dev->clk_freq = pdata->i2c_scl_freq;
 245         } else {
 246                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 247                                          &ht);
 248                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 249                                          &dev->sda_falling_time);
 250                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 251                                          &dev->scl_falling_time);
 252                 device_property_read_u32(&pdev->dev, "clock-frequency",
 253                                          &dev->clk_freq);
 254         }
 255
 256         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 257         /*
 258          * Find bus speed from the "clock-frequency" device property, ACPI
 259          * or by using fast mode if neither is set.
 260          */
 261         if (acpi_speed && dev->clk_freq)
 262                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
 263         else if (acpi_speed || dev->clk_freq)
 264                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
 265         else
 266                 dev->clk_freq = 400000;
 267
 268         if (has_acpi_companion(&pdev->dev))
 269                 dw_i2c_acpi_configure(pdev);
 270
 271         /*
 272          * Only standard mode at 100kHz, fast mode at 400kHz,
 273          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 274          */
 275         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 276             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 277                 dev_err(&pdev->dev,
 278                         "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
 279                 r = -EINVAL;
 280                 goto exit_reset;
 281         }
 282
 283         r = i2c_dw_probe_lock_support(dev);
 284         if (r)
 285                 goto exit_reset;
 286
 287         dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
 288
 289         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 290                           DW_IC_CON_RESTART_EN;
 291
 292         switch (dev->clk_freq) {
 293         case 100000:
 294                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
 295                 break;
 296         case 3400000:
 297                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
 298                 break;
 299         default:
 300                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
 301         }
 302
 303         dev->clk = devm_clk_get(&pdev->dev, NULL);
 304         if (!i2c_dw_plat_prepare_clk(dev, true)) {
 305                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 306
 307                 if (!dev->sda_hold_time && ht)
 308                         dev->sda_hold_time = div_u64(
 309                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 310                                 1000000);
 311         }
 312
 313         dw_i2c_set_fifo_size(dev, pdev->id);
 314
 315         adap = &dev->adapter;
 316         adap->owner = THIS_MODULE;
 317         adap->class = I2C_CLASS_DEPRECATED;
 318         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 319         adap->dev.of_node = pdev->dev.of_node;
 320
 321         if (dev->pm_disabled) {
 322                 pm_runtime_forbid(&pdev->dev);
 323         } else {
 324                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 325                 pm_runtime_use_autosuspend(&pdev->dev);
 326                 pm_runtime_set_active(&pdev->dev);
 327                 pm_runtime_enable(&pdev->dev);
 328         }
 329
 330         r = i2c_dw_probe(dev);
 331         if (r)
 332                 goto exit_probe;
 333
 334         return r;
 335
 336 exit_probe:
 337         if (!dev->pm_disabled)
 338                 pm_runtime_disable(&pdev->dev);
 339 exit_reset:
 340         if (!IS_ERR_OR_NULL(dev->rst))
 341                 reset_control_assert(dev->rst);
 342         return r;
 343 }
 344
 345 static int dw_i2c_plat_remove(struct platform_device *pdev)
 346 {
 347         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 348
 349         pm_runtime_get_sync(&pdev->dev);
 350
 351         i2c_del_adapter(&dev->adapter);
 352
 353         i2c_dw_disable(dev);
 354
 355         pm_runtime_dont_use_autosuspend(&pdev->dev);
 356         pm_runtime_put_sync(&pdev->dev);
 357         if (!dev->pm_disabled)
 358                 pm_runtime_disable(&pdev->dev);
 359         if (!IS_ERR_OR_NULL(dev->rst))
 360                 reset_control_assert(dev->rst);
 361
 362         i2c_dw_remove_lock_support(dev);
 363
 364         return 0;
 365 }
 366
 367 #ifdef CONFIG_OF
 368 static const struct of_device_id dw_i2c_of_match[] = {
 369         { .compatible = "snps,designware-i2c", },
 370         {},
 371 };
 372 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 373 #endif
 374
 375 #ifdef CONFIG_PM_SLEEP
 376 static int dw_i2c_plat_prepare(struct device *dev)
 377 {
 378         return pm_runtime_suspended(dev);
 379 }
 380
 381 static void dw_i2c_plat_complete(struct device *dev)
 382 {
 383         if (dev->power.direct_complete)
 384                 pm_request_resume(dev);
 385 }
 386 #else
 387 #define dw_i2c_plat_prepare     NULL
 388 #define dw_i2c_plat_complete    NULL
 389 #endif
 390
 391 #ifdef CONFIG_PM
 392 static int dw_i2c_plat_suspend(struct device *dev)
 393 {
 394         struct platform_device *pdev = to_platform_device(dev);
 395         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 396
 397         i2c_dw_disable(i_dev);
 398         i2c_dw_plat_prepare_clk(i_dev, false);
 399
 400         return 0;
 401 }
 402
 403 static int dw_i2c_plat_resume(struct device *dev)
 404 {
 405         struct platform_device *pdev = to_platform_device(dev);
 406         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 407
 408         i2c_dw_plat_prepare_clk(i_dev, true);
 409         i2c_dw_init(i_dev);
 410
 411         return 0;
 412 }
 413
 414 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 415         .prepare = dw_i2c_plat_prepare,
 416         .complete = dw_i2c_plat_complete,
 417         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 418         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 419 };
 420
 421 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 422 #else
 423 #define DW_I2C_DEV_PMOPS NULL
 424 #endif
 425
 426 /* work with hotplug and coldplug */
 427 MODULE_ALIAS("platform:i2c_designware");
 428
 429 static struct platform_driver dw_i2c_driver = {
 430         .probe = dw_i2c_plat_probe,
 431         .remove = dw_i2c_plat_remove,
 432         .driver         = {
 433                 .name   = "i2c_designware",
 434                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 435                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 436                 .pm     = DW_I2C_DEV_PMOPS,
 437         },
 438 };
 439
 440 static int __init dw_i2c_init_driver(void)
 441 {
 442         return platform_driver_register(&dw_i2c_driver);
 443 }
 444 subsys_initcall(dw_i2c_init_driver);
 445
 446 static void __exit dw_i2c_exit_driver(void)
 447 {
 448         platform_driver_unregister(&dw_i2c_driver);
 449 }
 450 module_exit(dw_i2c_exit_driver);
 451
 452 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 453 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 454 MODULE_LICENSE("GPL");