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/slab.h>
  42 #include <linux/acpi.h>
  43 #include <linux/platform_data/i2c-designware.h>
  44 #include "i2c-designware-core.h"
  45
  46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  47 {
  48         return clk_get_rate(dev->clk)/1000;
  49 }
  50
  51 #ifdef CONFIG_ACPI
  52 /*
  53  * The HCNT/LCNT information coming from ACPI should be the most accurate
  54  * for given platform. However, some systems get it wrong. On such systems
  55  * we get better results by calculating those based on the input clock.
  56  */
  57 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
  58         {
  59                 .ident = "Dell Inspiron 7348",
  60                 .matches = {
  61                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  62                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
  63                 },
  64         },
  65         { }
  66 };
  67
  68 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  69                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  70 {
  71         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  72         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  73         union acpi_object *obj;
  74
  75         if (dmi_check_system(dw_i2c_no_acpi_params))
  76                 return;
  77
  78         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  79                 return;
  80
  81         obj = (union acpi_object *)buf.pointer;
  82         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  83                 const union acpi_object *objs = obj->package.elements;
  84
  85                 *hcnt = (u16)objs[0].integer.value;
  86                 *lcnt = (u16)objs[1].integer.value;
  87                 if (sda_hold)
  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         const struct acpi_device_id *id;
  98
  99         dev->adapter.nr = -1;
 100         dev->tx_fifo_depth = 32;
 101         dev->rx_fifo_depth = 32;
 102
 103         /*
 104          * Try to get SDA hold time and *CNT values from an ACPI method if
 105          * it exists for both supported speed modes.
 106          */
 107         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
 108         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
 109                            &dev->sda_hold_time);
 110         dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, NULL);
 111         dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, NULL);
 112
 113         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 114         if (id && id->driver_data)
 115                 dev->accessor_flags |= (u32)id->driver_data;
 116
 117         return 0;
 118 }
 119
 120 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 121         { "INT33C2", 0 },
 122         { "INT33C3", 0 },
 123         { "INT3432", 0 },
 124         { "INT3433", 0 },
 125         { "80860F41", 0 },
 126         { "808622C1", 0 },
 127         { "AMD0010", ACCESS_INTR_MASK },
 128         { "AMDI0010", ACCESS_INTR_MASK },
 129         { "AMDI0510", 0 },
 130         { "APMC0D0F", 0 },
 131         { }
 132 };
 133 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 134 #else
 135 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 136 {
 137         return -ENODEV;
 138 }
 139 #endif
 140
 141 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 142 {
 143         if (IS_ERR(i_dev->clk))
 144                 return PTR_ERR(i_dev->clk);
 145
 146         if (prepare)
 147                 return clk_prepare_enable(i_dev->clk);
 148
 149         clk_disable_unprepare(i_dev->clk);
 150         return 0;
 151 }
 152
 153 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 154 {
 155         u32 param, tx_fifo_depth, rx_fifo_depth;
 156
 157         /*
 158          * Try to detect the FIFO depth if not set by interface driver,
 159          * the depth could be from 2 to 256 from HW spec.
 160          */
 161         param = i2c_dw_read_comp_param(dev);
 162         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 163         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 164         if (!dev->tx_fifo_depth) {
 165                 dev->tx_fifo_depth = tx_fifo_depth;
 166                 dev->rx_fifo_depth = rx_fifo_depth;
 167                 dev->adapter.nr = id;
 168         } else if (tx_fifo_depth >= 2) {
 169                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 170                                 tx_fifo_depth);
 171                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 172                                 rx_fifo_depth);
 173         }
 174 }
 175
 176 static int dw_i2c_plat_probe(struct platform_device *pdev)
 177 {
 178         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 179         struct dw_i2c_dev *dev;
 180         struct i2c_adapter *adap;
 181         struct resource *mem;
 182         int irq, r;
 183         u32 acpi_speed, ht = 0;
 184
 185         irq = platform_get_irq(pdev, 0);
 186         if (irq < 0)
 187                 return irq;
 188
 189         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 190         if (!dev)
 191                 return -ENOMEM;
 192
 193         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 194         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 195         if (IS_ERR(dev->base))
 196                 return PTR_ERR(dev->base);
 197
 198         dev->dev = &pdev->dev;
 199         dev->irq = irq;
 200         platform_set_drvdata(pdev, dev);
 201
 202         if (pdata) {
 203                 dev->clk_freq = pdata->i2c_scl_freq;
 204         } else {
 205                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 206                                          &ht);
 207                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 208                                          &dev->sda_falling_time);
 209                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 210                                          &dev->scl_falling_time);
 211                 device_property_read_u32(&pdev->dev, "clock-frequency",
 212                                          &dev->clk_freq);
 213         }
 214
 215         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 216         /*
 217          * Find bus speed from the "clock-frequency" device property, ACPI
 218          * or by using fast mode if neither is set.
 219          */
 220         if (acpi_speed && dev->clk_freq)
 221                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
 222         else if (acpi_speed || dev->clk_freq)
 223                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
 224         else
 225                 dev->clk_freq = 400000;
 226
 227         if (has_acpi_companion(&pdev->dev))
 228                 dw_i2c_acpi_configure(pdev);
 229
 230         /*
 231          * Only standard mode at 100kHz, fast mode at 400kHz,
 232          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 233          */
 234         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 235             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 236                 dev_err(&pdev->dev,
 237                         "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
 238                 return -EINVAL;
 239         }
 240
 241         r = i2c_dw_eval_lock_support(dev);
 242         if (r)
 243                 return r;
 244
 245         dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
 246
 247         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 248                           DW_IC_CON_RESTART_EN;
 249
 250         switch (dev->clk_freq) {
 251         case 100000:
 252                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
 253                 break;
 254         case 3400000:
 255                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
 256                 break;
 257         default:
 258                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
 259         }
 260
 261         dev->clk = devm_clk_get(&pdev->dev, NULL);
 262         if (!i2c_dw_plat_prepare_clk(dev, true)) {
 263                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 264
 265                 if (!dev->sda_hold_time && ht)
 266                         dev->sda_hold_time = div_u64(
 267                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 268                                 1000000);
 269         }
 270
 271         dw_i2c_set_fifo_size(dev, pdev->id);
 272
 273         adap = &dev->adapter;
 274         adap->owner = THIS_MODULE;
 275         adap->class = I2C_CLASS_DEPRECATED;
 276         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 277         adap->dev.of_node = pdev->dev.of_node;
 278
 279         if (dev->pm_runtime_disabled) {
 280                 pm_runtime_forbid(&pdev->dev);
 281         } else {
 282                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 283                 pm_runtime_use_autosuspend(&pdev->dev);
 284                 pm_runtime_set_active(&pdev->dev);
 285                 pm_runtime_enable(&pdev->dev);
 286         }
 287
 288         r = i2c_dw_probe(dev);
 289         if (r && !dev->pm_runtime_disabled)
 290                 pm_runtime_disable(&pdev->dev);
 291
 292         return r;
 293 }
 294
 295 static int dw_i2c_plat_remove(struct platform_device *pdev)
 296 {
 297         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 298
 299         pm_runtime_get_sync(&pdev->dev);
 300
 301         i2c_del_adapter(&dev->adapter);
 302
 303         i2c_dw_disable(dev);
 304
 305         pm_runtime_dont_use_autosuspend(&pdev->dev);
 306         pm_runtime_put_sync(&pdev->dev);
 307         if (!dev->pm_runtime_disabled)
 308                 pm_runtime_disable(&pdev->dev);
 309
 310         return 0;
 311 }
 312
 313 #ifdef CONFIG_OF
 314 static const struct of_device_id dw_i2c_of_match[] = {
 315         { .compatible = "snps,designware-i2c", },
 316         {},
 317 };
 318 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 319 #endif
 320
 321 #ifdef CONFIG_PM_SLEEP
 322 static int dw_i2c_plat_prepare(struct device *dev)
 323 {
 324         return pm_runtime_suspended(dev);
 325 }
 326
 327 static void dw_i2c_plat_complete(struct device *dev)
 328 {
 329         if (dev->power.direct_complete)
 330                 pm_request_resume(dev);
 331 }
 332 #else
 333 #define dw_i2c_plat_prepare     NULL
 334 #define dw_i2c_plat_complete    NULL
 335 #endif
 336
 337 #ifdef CONFIG_PM
 338 static int dw_i2c_plat_suspend(struct device *dev)
 339 {
 340         struct platform_device *pdev = to_platform_device(dev);
 341         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 342
 343         i2c_dw_disable(i_dev);
 344         i2c_dw_plat_prepare_clk(i_dev, false);
 345
 346         return 0;
 347 }
 348
 349 static int dw_i2c_plat_resume(struct device *dev)
 350 {
 351         struct platform_device *pdev = to_platform_device(dev);
 352         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 353
 354         i2c_dw_plat_prepare_clk(i_dev, true);
 355
 356         if (!i_dev->pm_runtime_disabled)
 357                 i2c_dw_init(i_dev);
 358
 359         return 0;
 360 }
 361
 362 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 363         .prepare = dw_i2c_plat_prepare,
 364         .complete = dw_i2c_plat_complete,
 365         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 366         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 367 };
 368
 369 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 370 #else
 371 #define DW_I2C_DEV_PMOPS NULL
 372 #endif
 373
 374 /* work with hotplug and coldplug */
 375 MODULE_ALIAS("platform:i2c_designware");
 376
 377 static struct platform_driver dw_i2c_driver = {
 378         .probe = dw_i2c_plat_probe,
 379         .remove = dw_i2c_plat_remove,
 380         .driver         = {
 381                 .name   = "i2c_designware",
 382                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 383                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 384                 .pm     = DW_I2C_DEV_PMOPS,
 385         },
 386 };
 387
 388 static int __init dw_i2c_init_driver(void)
 389 {
 390         return platform_driver_register(&dw_i2c_driver);
 391 }
 392 subsys_initcall(dw_i2c_init_driver);
 393
 394 static void __exit dw_i2c_exit_driver(void)
 395 {
 396         platform_driver_unregister(&dw_i2c_driver);
 397 }
 398 module_exit(dw_i2c_exit_driver);
 399
 400 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 401 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 402 MODULE_LICENSE("GPL");