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/io.h>
  40 #include <linux/slab.h>
  41 #include <linux/acpi.h>
  42 #include <linux/platform_data/i2c-designware.h>
  43 #include "i2c-designware-core.h"
  44
  45 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  46 {
  47         return clk_get_rate(dev->clk)/1000;
  48 }
  49
  50 #ifdef CONFIG_ACPI
  51 /*
  52  * The HCNT/LCNT information coming from ACPI should be the most accurate
  53  * for given platform. However, some systems get it wrong. On such systems
  54  * we get better results by calculating those based on the input clock.
  55  */
  56 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
  57         {
  58                 .ident = "Dell Inspiron 7348",
  59                 .matches = {
  60                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  61                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
  62                 },
  63         },
  64         { }
  65 };
  66
  67 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  68                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  69 {
  70         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  71         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  72         union acpi_object *obj;
  73
  74         if (dmi_check_system(dw_i2c_no_acpi_params))
  75                 return;
  76
  77         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  78                 return;
  79
  80         obj = (union acpi_object *)buf.pointer;
  81         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  82                 const union acpi_object *objs = obj->package.elements;
  83
  84                 *hcnt = (u16)objs[0].integer.value;
  85                 *lcnt = (u16)objs[1].integer.value;
  86                 if (sda_hold)
  87                         *sda_hold = (u32)objs[2].integer.value;
  88         }
  89
  90         kfree(buf.pointer);
  91 }
  92
  93 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  94 {
  95         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  96         const struct acpi_device_id *id;
  97
  98         dev->adapter.nr = -1;
  99         dev->tx_fifo_depth = 32;
 100         dev->rx_fifo_depth = 32;
 101
 102         /*
 103          * Try to get SDA hold time and *CNT values from an ACPI method if
 104          * it exists for both supported speed modes.
 105          */
 106         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
 107         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
 108                            &dev->sda_hold_time);
 109
 110         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 111         if (id && id->driver_data)
 112                 dev->accessor_flags |= (u32)id->driver_data;
 113
 114         return 0;
 115 }
 116
 117 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 118         { "INT33C2", 0 },
 119         { "INT33C3", 0 },
 120         { "INT3432", 0 },
 121         { "INT3433", 0 },
 122         { "80860F41", 0 },
 123         { "808622C1", 0 },
 124         { "AMD0010", ACCESS_INTR_MASK },
 125         { }
 126 };
 127 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 128 #else
 129 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 130 {
 131         return -ENODEV;
 132 }
 133 #endif
 134
 135 static int dw_i2c_plat_probe(struct platform_device *pdev)
 136 {
 137         struct dw_i2c_dev *dev;
 138         struct i2c_adapter *adap;
 139         struct resource *mem;
 140         struct dw_i2c_platform_data *pdata;
 141         int irq, r;
 142         u32 clk_freq, ht = 0;
 143
 144         irq = platform_get_irq(pdev, 0);
 145         if (irq < 0)
 146                 return irq;
 147
 148         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 149         if (!dev)
 150                 return -ENOMEM;
 151
 152         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 153         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 154         if (IS_ERR(dev->base))
 155                 return PTR_ERR(dev->base);
 156
 157         dev->dev = &pdev->dev;
 158         dev->irq = irq;
 159         platform_set_drvdata(pdev, dev);
 160
 161         /* fast mode by default because of legacy reasons */
 162         clk_freq = 400000;
 163
 164         if (has_acpi_companion(&pdev->dev)) {
 165                 dw_i2c_acpi_configure(pdev);
 166         } else if (pdev->dev.of_node) {
 167                 of_property_read_u32(pdev->dev.of_node,
 168                                         "i2c-sda-hold-time-ns", &ht);
 169
 170                 of_property_read_u32(pdev->dev.of_node,
 171                                      "i2c-sda-falling-time-ns",
 172                                      &dev->sda_falling_time);
 173                 of_property_read_u32(pdev->dev.of_node,
 174                                      "i2c-scl-falling-time-ns",
 175                                      &dev->scl_falling_time);
 176
 177                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 178                                      &clk_freq);
 179
 180                 /* Only standard mode at 100kHz and fast mode at 400kHz
 181                  * are supported.
 182                  */
 183                 if (clk_freq != 100000 && clk_freq != 400000) {
 184                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 185                         return -EINVAL;
 186                 }
 187         } else {
 188                 pdata = dev_get_platdata(&pdev->dev);
 189                 if (pdata)
 190                         clk_freq = pdata->i2c_scl_freq;
 191         }
 192
 193         r = i2c_dw_eval_lock_support(dev);
 194         if (r)
 195                 return r;
 196
 197         dev->functionality =
 198                 I2C_FUNC_I2C |
 199                 I2C_FUNC_10BIT_ADDR |
 200                 I2C_FUNC_SMBUS_BYTE |
 201                 I2C_FUNC_SMBUS_BYTE_DATA |
 202                 I2C_FUNC_SMBUS_WORD_DATA |
 203                 I2C_FUNC_SMBUS_I2C_BLOCK;
 204         if (clk_freq == 100000)
 205                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 206                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 207         else
 208                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 209                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 210
 211         dev->clk = devm_clk_get(&pdev->dev, NULL);
 212         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 213         if (IS_ERR(dev->clk))
 214                 return PTR_ERR(dev->clk);
 215         clk_prepare_enable(dev->clk);
 216
 217         if (!dev->sda_hold_time && ht) {
 218                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 219
 220                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 221                                              1000000);
 222         }
 223
 224         if (!dev->tx_fifo_depth) {
 225                 u32 param1 = i2c_dw_read_comp_param(dev);
 226
 227                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 228                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 229                 dev->adapter.nr = pdev->id;
 230         }
 231
 232         adap = &dev->adapter;
 233         adap->owner = THIS_MODULE;
 234         adap->class = I2C_CLASS_DEPRECATED;
 235         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 236         adap->dev.of_node = pdev->dev.of_node;
 237
 238         if (dev->pm_runtime_disabled) {
 239                 pm_runtime_forbid(&pdev->dev);
 240         } else {
 241                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 242                 pm_runtime_use_autosuspend(&pdev->dev);
 243                 pm_runtime_set_active(&pdev->dev);
 244                 pm_runtime_enable(&pdev->dev);
 245         }
 246
 247         r = i2c_dw_probe(dev);
 248         if (r) {
 249                 pm_runtime_disable(&pdev->dev);
 250                 return r;
 251         }
 252
 253         return 0;
 254 }
 255
 256 static int dw_i2c_plat_remove(struct platform_device *pdev)
 257 {
 258         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 259
 260         pm_runtime_get_sync(&pdev->dev);
 261
 262         i2c_del_adapter(&dev->adapter);
 263
 264         i2c_dw_disable(dev);
 265
 266         pm_runtime_dont_use_autosuspend(&pdev->dev);
 267         pm_runtime_put_sync(&pdev->dev);
 268         pm_runtime_disable(&pdev->dev);
 269
 270         return 0;
 271 }
 272
 273 #ifdef CONFIG_OF
 274 static const struct of_device_id dw_i2c_of_match[] = {
 275         { .compatible = "snps,designware-i2c", },
 276         {},
 277 };
 278 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 279 #endif
 280
 281 #ifdef CONFIG_PM_SLEEP
 282 static int dw_i2c_plat_prepare(struct device *dev)
 283 {
 284         return pm_runtime_suspended(dev);
 285 }
 286
 287 static void dw_i2c_plat_complete(struct device *dev)
 288 {
 289         if (dev->power.direct_complete)
 290                 pm_request_resume(dev);
 291 }
 292 #else
 293 #define dw_i2c_plat_prepare     NULL
 294 #define dw_i2c_plat_complete    NULL
 295 #endif
 296
 297 #ifdef CONFIG_PM
 298 static int dw_i2c_plat_suspend(struct device *dev)
 299 {
 300         struct platform_device *pdev = to_platform_device(dev);
 301         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 302
 303         i2c_dw_disable(i_dev);
 304         clk_disable_unprepare(i_dev->clk);
 305
 306         return 0;
 307 }
 308
 309 static int dw_i2c_plat_resume(struct device *dev)
 310 {
 311         struct platform_device *pdev = to_platform_device(dev);
 312         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 313
 314         clk_prepare_enable(i_dev->clk);
 315
 316         if (!i_dev->pm_runtime_disabled)
 317                 i2c_dw_init(i_dev);
 318
 319         return 0;
 320 }
 321
 322 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 323         .prepare = dw_i2c_plat_prepare,
 324         .complete = dw_i2c_plat_complete,
 325         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 326         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 327 };
 328
 329 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 330 #else
 331 #define DW_I2C_DEV_PMOPS NULL
 332 #endif
 333
 334 /* work with hotplug and coldplug */
 335 MODULE_ALIAS("platform:i2c_designware");
 336
 337 static struct platform_driver dw_i2c_driver = {
 338         .probe = dw_i2c_plat_probe,
 339         .remove = dw_i2c_plat_remove,
 340         .driver         = {
 341                 .name   = "i2c_designware",
 342                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 343                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 344                 .pm     = DW_I2C_DEV_PMOPS,
 345         },
 346 };
 347
 348 static int __init dw_i2c_init_driver(void)
 349 {
 350         return platform_driver_register(&dw_i2c_driver);
 351 }
 352 subsys_initcall(dw_i2c_init_driver);
 353
 354 static void __exit dw_i2c_exit_driver(void)
 355 {
 356         platform_driver_unregister(&dw_i2c_driver);
 357 }
 358 module_exit(dw_i2c_exit_driver);
 359
 360 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 361 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 362 MODULE_LICENSE("GPL");