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