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