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         const struct acpi_device_id *id;
  99
 100         dev->adapter.nr = -1;
 101         dev->tx_fifo_depth = 32;
 102         dev->rx_fifo_depth = 32;
 103
 104         /*
 105          * Try to get SDA hold time and *CNT values from an ACPI method if
 106          * it exists for both supported speed modes.
 107          */
 108         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
 109         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
 110                            &dev->sda_hold_time);
 111         dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, NULL);
 112         dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, NULL);
 113
 114         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 115         if (id && id->driver_data)
 116                 dev->accessor_flags |= (u32)id->driver_data;
 117
 118         return 0;
 119 }
 120
 121 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 122         { "INT33C2", 0 },
 123         { "INT33C3", 0 },
 124         { "INT3432", 0 },
 125         { "INT3433", 0 },
 126         { "80860F41", 0 },
 127         { "808622C1", 0 },
 128         { "AMD0010", ACCESS_INTR_MASK },
 129         { "AMDI0010", ACCESS_INTR_MASK },
 130         { "AMDI0510", 0 },
 131         { "APMC0D0F", 0 },
 132         { }
 133 };
 134 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 135 #else
 136 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 137 {
 138         return -ENODEV;
 139 }
 140 #endif
 141
 142 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 143 {
 144         if (IS_ERR(i_dev->clk))
 145                 return PTR_ERR(i_dev->clk);
 146
 147         if (prepare)
 148                 return clk_prepare_enable(i_dev->clk);
 149
 150         clk_disable_unprepare(i_dev->clk);
 151         return 0;
 152 }
 153
 154 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 155 {
 156         u32 param, tx_fifo_depth, rx_fifo_depth;
 157
 158         /*
 159          * Try to detect the FIFO depth if not set by interface driver,
 160          * the depth could be from 2 to 256 from HW spec.
 161          */
 162         param = i2c_dw_read_comp_param(dev);
 163         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 164         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 165         if (!dev->tx_fifo_depth) {
 166                 dev->tx_fifo_depth = tx_fifo_depth;
 167                 dev->rx_fifo_depth = rx_fifo_depth;
 168                 dev->adapter.nr = id;
 169         } else if (tx_fifo_depth >= 2) {
 170                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 171                                 tx_fifo_depth);
 172                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 173                                 rx_fifo_depth);
 174         }
 175 }
 176
 177 static int dw_i2c_plat_probe(struct platform_device *pdev)
 178 {
 179         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 180         struct dw_i2c_dev *dev;
 181         struct i2c_adapter *adap;
 182         struct resource *mem;
 183         int irq, r;
 184         u32 acpi_speed, ht = 0;
 185
 186         irq = platform_get_irq(pdev, 0);
 187         if (irq < 0)
 188                 return irq;
 189
 190         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 191         if (!dev)
 192                 return -ENOMEM;
 193
 194         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 195         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 196         if (IS_ERR(dev->base))
 197                 return PTR_ERR(dev->base);
 198
 199         dev->dev = &pdev->dev;
 200         dev->irq = irq;
 201         platform_set_drvdata(pdev, dev);
 202
 203         dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 204         if (IS_ERR(dev->rst)) {
 205                 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
 206                         return -EPROBE_DEFER;
 207         } else {
 208                 reset_control_deassert(dev->rst);
 209         }
 210
 211         if (pdata) {
 212                 dev->clk_freq = pdata->i2c_scl_freq;
 213         } else {
 214                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 215                                          &ht);
 216                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 217                                          &dev->sda_falling_time);
 218                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 219                                          &dev->scl_falling_time);
 220                 device_property_read_u32(&pdev->dev, "clock-frequency",
 221                                          &dev->clk_freq);
 222         }
 223
 224         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 225         /*
 226          * Find bus speed from the "clock-frequency" device property, ACPI
 227          * or by using fast mode if neither is set.
 228          */
 229         if (acpi_speed && dev->clk_freq)
 230                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
 231         else if (acpi_speed || dev->clk_freq)
 232                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
 233         else
 234                 dev->clk_freq = 400000;
 235
 236         if (has_acpi_companion(&pdev->dev))
 237                 dw_i2c_acpi_configure(pdev);
 238
 239         /*
 240          * Only standard mode at 100kHz, fast mode at 400kHz,
 241          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 242          */
 243         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 244             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 245                 dev_err(&pdev->dev,
 246                         "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
 247                 r = -EINVAL;
 248                 goto exit_reset;
 249         }
 250
 251         r = i2c_dw_eval_lock_support(dev);
 252         if (r)
 253                 goto exit_reset;
 254
 255         dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
 256
 257         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 258                           DW_IC_CON_RESTART_EN;
 259
 260         switch (dev->clk_freq) {
 261         case 100000:
 262                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
 263                 break;
 264         case 3400000:
 265                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
 266                 break;
 267         default:
 268                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
 269         }
 270
 271         dev->clk = devm_clk_get(&pdev->dev, NULL);
 272         if (!i2c_dw_plat_prepare_clk(dev, true)) {
 273                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 274
 275                 if (!dev->sda_hold_time && ht)
 276                         dev->sda_hold_time = div_u64(
 277                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 278                                 1000000);
 279         }
 280
 281         dw_i2c_set_fifo_size(dev, pdev->id);
 282
 283         adap = &dev->adapter;
 284         adap->owner = THIS_MODULE;
 285         adap->class = I2C_CLASS_DEPRECATED;
 286         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 287         adap->dev.of_node = pdev->dev.of_node;
 288
 289         if (dev->pm_runtime_disabled) {
 290                 pm_runtime_forbid(&pdev->dev);
 291         } else {
 292                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 293                 pm_runtime_use_autosuspend(&pdev->dev);
 294                 pm_runtime_set_active(&pdev->dev);
 295                 pm_runtime_enable(&pdev->dev);
 296         }
 297
 298         r = i2c_dw_probe(dev);
 299         if (r)
 300                 goto exit_probe;
 301
 302         return r;
 303
 304 exit_probe:
 305         if (!dev->pm_runtime_disabled)
 306                 pm_runtime_disable(&pdev->dev);
 307 exit_reset:
 308         if (!IS_ERR_OR_NULL(dev->rst))
 309                 reset_control_assert(dev->rst);
 310         return r;
 311 }
 312
 313 static int dw_i2c_plat_remove(struct platform_device *pdev)
 314 {
 315         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 316
 317         pm_runtime_get_sync(&pdev->dev);
 318
 319         i2c_del_adapter(&dev->adapter);
 320
 321         i2c_dw_disable(dev);
 322
 323         pm_runtime_dont_use_autosuspend(&pdev->dev);
 324         pm_runtime_put_sync(&pdev->dev);
 325         if (!dev->pm_runtime_disabled)
 326                 pm_runtime_disable(&pdev->dev);
 327         if (!IS_ERR_OR_NULL(dev->rst))
 328                 reset_control_assert(dev->rst);
 329
 330         return 0;
 331 }
 332
 333 #ifdef CONFIG_OF
 334 static const struct of_device_id dw_i2c_of_match[] = {
 335         { .compatible = "snps,designware-i2c", },
 336         {},
 337 };
 338 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 339 #endif
 340
 341 #ifdef CONFIG_PM_SLEEP
 342 static int dw_i2c_plat_prepare(struct device *dev)
 343 {
 344         return pm_runtime_suspended(dev);
 345 }
 346
 347 static void dw_i2c_plat_complete(struct device *dev)
 348 {
 349         if (dev->power.direct_complete)
 350                 pm_request_resume(dev);
 351 }
 352 #else
 353 #define dw_i2c_plat_prepare     NULL
 354 #define dw_i2c_plat_complete    NULL
 355 #endif
 356
 357 #ifdef CONFIG_PM
 358 static int dw_i2c_plat_suspend(struct device *dev)
 359 {
 360         struct platform_device *pdev = to_platform_device(dev);
 361         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 362
 363         i2c_dw_disable(i_dev);
 364         i2c_dw_plat_prepare_clk(i_dev, false);
 365
 366         return 0;
 367 }
 368
 369 static int dw_i2c_plat_resume(struct device *dev)
 370 {
 371         struct platform_device *pdev = to_platform_device(dev);
 372         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 373
 374         i2c_dw_plat_prepare_clk(i_dev, true);
 375
 376         if (!i_dev->pm_runtime_disabled)
 377                 i2c_dw_init(i_dev);
 378
 379         return 0;
 380 }
 381
 382 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 383         .prepare = dw_i2c_plat_prepare,
 384         .complete = dw_i2c_plat_complete,
 385         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 386         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 387 };
 388
 389 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 390 #else
 391 #define DW_I2C_DEV_PMOPS NULL
 392 #endif
 393
 394 /* work with hotplug and coldplug */
 395 MODULE_ALIAS("platform:i2c_designware");
 396
 397 static struct platform_driver dw_i2c_driver = {
 398         .probe = dw_i2c_plat_probe,
 399         .remove = dw_i2c_plat_remove,
 400         .driver         = {
 401                 .name   = "i2c_designware",
 402                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 403                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 404                 .pm     = DW_I2C_DEV_PMOPS,
 405         },
 406 };
 407
 408 static int __init dw_i2c_init_driver(void)
 409 {
 410         return platform_driver_register(&dw_i2c_driver);
 411 }
 412 subsys_initcall(dw_i2c_init_driver);
 413
 414 static void __exit dw_i2c_exit_driver(void)
 415 {
 416         platform_driver_unregister(&dw_i2c_driver);
 417 }
 418 module_exit(dw_i2c_exit_driver);
 419
 420 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 421 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 422 MODULE_LICENSE("GPL");