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 struct i2c_algorithm i2c_dw_algo = {
  46         .master_xfer    = i2c_dw_xfer,
  47         .functionality  = i2c_dw_func,
  48 };
  49 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  50 {
  51         return clk_get_rate(dev->clk)/1000;
  52 }
  53
  54 #ifdef CONFIG_ACPI
  55 /*
  56  * The HCNT/LCNT information coming from ACPI should be the most accurate
  57  * for given platform. However, some systems get it wrong. On such systems
  58  * we get better results by calculating those based on the input clock.
  59  */
  60 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
  61         {
  62                 .ident = "Dell Inspiron 7348",
  63                 .matches = {
  64                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  65                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
  66                 },
  67         },
  68         { }
  69 };
  70
  71 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  72                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  73 {
  74         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  75         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  76         union acpi_object *obj;
  77
  78         if (dmi_check_system(dw_i2c_no_acpi_params))
  79                 return;
  80
  81         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  82                 return;
  83
  84         obj = (union acpi_object *)buf.pointer;
  85         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  86                 const union acpi_object *objs = obj->package.elements;
  87
  88                 *hcnt = (u16)objs[0].integer.value;
  89                 *lcnt = (u16)objs[1].integer.value;
  90                 if (sda_hold)
  91                         *sda_hold = (u32)objs[2].integer.value;
  92         }
  93
  94         kfree(buf.pointer);
  95 }
  96
  97 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  98 {
  99         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 100         const struct acpi_device_id *id;
 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 if
 108          * it exists for both supported speed modes.
 109          */
 110         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
 111         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
 112                            &dev->sda_hold_time);
 113
 114         /*
 115          * Provide a way for Designware I2C host controllers that are not
 116          * based on Intel LPSS to specify their input clock frequency via
 117          * id->driver_data.
 118          */
 119         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 120         if (id && id->driver_data)
 121                 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
 122                                         CLK_IS_ROOT, id->driver_data);
 123
 124         return 0;
 125 }
 126
 127 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
 128 {
 129         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 130         const struct acpi_device_id *id;
 131
 132         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 133         if (id && id->driver_data)
 134                 clk_unregister(dev->clk);
 135 }
 136
 137 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 138         { "INT33C2", 0 },
 139         { "INT33C3", 0 },
 140         { "INT3432", 0 },
 141         { "INT3433", 0 },
 142         { "80860F41", 0 },
 143         { "808622C1", 0 },
 144         { "AMD0010", 133 * 1000 * 1000 },
 145         { }
 146 };
 147 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 148 #else
 149 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 150 {
 151         return -ENODEV;
 152 }
 153 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
 154 #endif
 155
 156 static int dw_i2c_probe(struct platform_device *pdev)
 157 {
 158         struct dw_i2c_dev *dev;
 159         struct i2c_adapter *adap;
 160         struct resource *mem;
 161         struct dw_i2c_platform_data *pdata;
 162         int irq, r;
 163         u32 clk_freq, ht = 0;
 164
 165         irq = platform_get_irq(pdev, 0);
 166         if (irq < 0)
 167                 return irq;
 168
 169         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 170         if (!dev)
 171                 return -ENOMEM;
 172
 173         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 174         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 175         if (IS_ERR(dev->base))
 176                 return PTR_ERR(dev->base);
 177
 178         init_completion(&dev->cmd_complete);
 179         mutex_init(&dev->lock);
 180         dev->dev = &pdev->dev;
 181         dev->irq = irq;
 182         platform_set_drvdata(pdev, dev);
 183
 184         /* fast mode by default because of legacy reasons */
 185         clk_freq = 400000;
 186
 187         if (has_acpi_companion(&pdev->dev)) {
 188                 dw_i2c_acpi_configure(pdev);
 189         } else if (pdev->dev.of_node) {
 190                 of_property_read_u32(pdev->dev.of_node,
 191                                         "i2c-sda-hold-time-ns", &ht);
 192
 193                 of_property_read_u32(pdev->dev.of_node,
 194                                      "i2c-sda-falling-time-ns",
 195                                      &dev->sda_falling_time);
 196                 of_property_read_u32(pdev->dev.of_node,
 197                                      "i2c-scl-falling-time-ns",
 198                                      &dev->scl_falling_time);
 199
 200                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 201                                      &clk_freq);
 202
 203                 /* Only standard mode at 100kHz and fast mode at 400kHz
 204                  * are supported.
 205                  */
 206                 if (clk_freq != 100000 && clk_freq != 400000) {
 207                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 208                         return -EINVAL;
 209                 }
 210         } else {
 211                 pdata = dev_get_platdata(&pdev->dev);
 212                 if (pdata)
 213                         clk_freq = pdata->i2c_scl_freq;
 214         }
 215
 216         r = i2c_dw_eval_lock_support(dev);
 217         if (r)
 218                 return r;
 219
 220         dev->functionality =
 221                 I2C_FUNC_I2C |
 222                 I2C_FUNC_10BIT_ADDR |
 223                 I2C_FUNC_SMBUS_BYTE |
 224                 I2C_FUNC_SMBUS_BYTE_DATA |
 225                 I2C_FUNC_SMBUS_WORD_DATA |
 226                 I2C_FUNC_SMBUS_I2C_BLOCK;
 227         if (clk_freq == 100000)
 228                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 229                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 230         else
 231                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 232                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 233
 234         dev->clk = devm_clk_get(&pdev->dev, NULL);
 235         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 236         if (IS_ERR(dev->clk))
 237                 return PTR_ERR(dev->clk);
 238         clk_prepare_enable(dev->clk);
 239
 240         if (!dev->sda_hold_time && ht) {
 241                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 242
 243                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 244                                              1000000);
 245         }
 246
 247         if (!dev->tx_fifo_depth) {
 248                 u32 param1 = i2c_dw_read_comp_param(dev);
 249
 250                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 251                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 252                 dev->adapter.nr = pdev->id;
 253         }
 254         r = i2c_dw_init(dev);
 255         if (r)
 256                 return r;
 257
 258         i2c_dw_disable_int(dev);
 259         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
 260                         pdev->name, dev);
 261         if (r) {
 262                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 263                 return r;
 264         }
 265
 266         adap = &dev->adapter;
 267         i2c_set_adapdata(adap, dev);
 268         adap->owner = THIS_MODULE;
 269         adap->class = I2C_CLASS_DEPRECATED;
 270         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 271                         sizeof(adap->name));
 272         adap->algo = &i2c_dw_algo;
 273         adap->dev.parent = &pdev->dev;
 274         adap->dev.of_node = pdev->dev.of_node;
 275
 276         if (dev->pm_runtime_disabled) {
 277                 pm_runtime_forbid(&pdev->dev);
 278         } else {
 279                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 280                 pm_runtime_use_autosuspend(&pdev->dev);
 281                 pm_runtime_set_active(&pdev->dev);
 282                 pm_runtime_enable(&pdev->dev);
 283         }
 284
 285         r = i2c_add_numbered_adapter(adap);
 286         if (r) {
 287                 dev_err(&pdev->dev, "failure adding adapter\n");
 288                 pm_runtime_disable(&pdev->dev);
 289                 return r;
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int dw_i2c_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_put(&pdev->dev);
 306         pm_runtime_disable(&pdev->dev);
 307
 308         if (has_acpi_companion(&pdev->dev))
 309                 dw_i2c_acpi_unconfigure(pdev);
 310
 311         return 0;
 312 }
 313
 314 #ifdef CONFIG_OF
 315 static const struct of_device_id dw_i2c_of_match[] = {
 316         { .compatible = "snps,designware-i2c", },
 317         {},
 318 };
 319 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 320 #endif
 321
 322 #ifdef CONFIG_PM
 323 static int dw_i2c_suspend(struct device *dev)
 324 {
 325         struct platform_device *pdev = to_platform_device(dev);
 326         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 327
 328         i2c_dw_disable(i_dev);
 329         clk_disable_unprepare(i_dev->clk);
 330
 331         return 0;
 332 }
 333
 334 static int dw_i2c_resume(struct device *dev)
 335 {
 336         struct platform_device *pdev = to_platform_device(dev);
 337         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 338
 339         clk_prepare_enable(i_dev->clk);
 340
 341         if (!i_dev->pm_runtime_disabled)
 342                 i2c_dw_init(i_dev);
 343
 344         return 0;
 345 }
 346 #endif
 347
 348 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
 349                             dw_i2c_resume, NULL);
 350
 351 /* work with hotplug and coldplug */
 352 MODULE_ALIAS("platform:i2c_designware");
 353
 354 static struct platform_driver dw_i2c_driver = {
 355         .probe = dw_i2c_probe,
 356         .remove = dw_i2c_remove,
 357         .driver         = {
 358                 .name   = "i2c_designware",
 359                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 360                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 361                 .pm     = &dw_i2c_dev_pm_ops,
 362         },
 363 };
 364
 365 static int __init dw_i2c_init_driver(void)
 366 {
 367         return platform_driver_register(&dw_i2c_driver);
 368 }
 369 subsys_initcall(dw_i2c_init_driver);
 370
 371 static void __exit dw_i2c_exit_driver(void)
 372 {
 373         platform_driver_unregister(&dw_i2c_driver);
 374 }
 375 module_exit(dw_i2c_exit_driver);
 376
 377 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 378 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 379 MODULE_LICENSE("GPL");