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