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
 111         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 112         if (id && id->driver_data)
 113                 dev->accessor_flags |= (u32)id->driver_data;
 114
 115         return 0;
 116 }
 117
 118 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 119         { "INT33C2", 0 },
 120         { "INT33C3", 0 },
 121         { "INT3432", 0 },
 122         { "INT3433", 0 },
 123         { "80860F41", 0 },
 124         { "808622C1", 0 },
 125         { "AMD0010", ACCESS_INTR_MASK },
 126         { }
 127 };
 128 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 129 #else
 130 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 131 {
 132         return -ENODEV;
 133 }
 134 #endif
 135
 136 static int dw_i2c_plat_probe(struct platform_device *pdev)
 137 {
 138         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 139         struct dw_i2c_dev *dev;
 140         struct i2c_adapter *adap;
 141         struct resource *mem;
 142         int irq, r;
 143         u32 clk_freq, ht = 0;
 144
 145         irq = platform_get_irq(pdev, 0);
 146         if (irq < 0)
 147                 return irq;
 148
 149         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 150         if (!dev)
 151                 return -ENOMEM;
 152
 153         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 154         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 155         if (IS_ERR(dev->base))
 156                 return PTR_ERR(dev->base);
 157
 158         dev->dev = &pdev->dev;
 159         dev->irq = irq;
 160         platform_set_drvdata(pdev, dev);
 161
 162         /* fast mode by default because of legacy reasons */
 163         clk_freq = 400000;
 164
 165         if (pdata) {
 166                 clk_freq = pdata->i2c_scl_freq;
 167         } else {
 168                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 169                                          &ht);
 170                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 171                                          &dev->sda_falling_time);
 172                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 173                                          &dev->scl_falling_time);
 174                 device_property_read_u32(&pdev->dev, "clock-frequency",
 175                                          &clk_freq);
 176         }
 177
 178         if (has_acpi_companion(&pdev->dev))
 179                 dw_i2c_acpi_configure(pdev);
 180
 181         /*
 182          * Only standard mode at 100kHz and fast mode at 400kHz are supported.
 183          */
 184         if (clk_freq != 100000 && clk_freq != 400000) {
 185                 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 186                 return -EINVAL;
 187         }
 188
 189         r = i2c_dw_eval_lock_support(dev);
 190         if (r)
 191                 return r;
 192
 193         dev->functionality =
 194                 I2C_FUNC_I2C |
 195                 I2C_FUNC_10BIT_ADDR |
 196                 I2C_FUNC_SMBUS_BYTE |
 197                 I2C_FUNC_SMBUS_BYTE_DATA |
 198                 I2C_FUNC_SMBUS_WORD_DATA |
 199                 I2C_FUNC_SMBUS_I2C_BLOCK;
 200         if (clk_freq == 100000)
 201                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 202                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 203         else
 204                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 205                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 206
 207         dev->clk = devm_clk_get(&pdev->dev, NULL);
 208         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 209         if (IS_ERR(dev->clk))
 210                 return PTR_ERR(dev->clk);
 211         clk_prepare_enable(dev->clk);
 212
 213         if (!dev->sda_hold_time && ht) {
 214                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 215
 216                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 217                                              1000000);
 218         }
 219
 220         if (!dev->tx_fifo_depth) {
 221                 u32 param1 = i2c_dw_read_comp_param(dev);
 222
 223                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 224                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 225                 dev->adapter.nr = pdev->id;
 226         }
 227
 228         adap = &dev->adapter;
 229         adap->owner = THIS_MODULE;
 230         adap->class = I2C_CLASS_DEPRECATED;
 231         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 232         adap->dev.of_node = pdev->dev.of_node;
 233
 234         if (dev->pm_runtime_disabled) {
 235                 pm_runtime_forbid(&pdev->dev);
 236         } else {
 237                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 238                 pm_runtime_use_autosuspend(&pdev->dev);
 239                 pm_runtime_set_active(&pdev->dev);
 240                 pm_runtime_enable(&pdev->dev);
 241         }
 242
 243         r = i2c_dw_probe(dev);
 244         if (r && !dev->pm_runtime_disabled)
 245                 pm_runtime_disable(&pdev->dev);
 246
 247         return r;
 248 }
 249
 250 static int dw_i2c_plat_remove(struct platform_device *pdev)
 251 {
 252         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 253
 254         pm_runtime_get_sync(&pdev->dev);
 255
 256         i2c_del_adapter(&dev->adapter);
 257
 258         i2c_dw_disable(dev);
 259
 260         pm_runtime_dont_use_autosuspend(&pdev->dev);
 261         pm_runtime_put_sync(&pdev->dev);
 262         if (!dev->pm_runtime_disabled)
 263                 pm_runtime_disable(&pdev->dev);
 264
 265         return 0;
 266 }
 267
 268 #ifdef CONFIG_OF
 269 static const struct of_device_id dw_i2c_of_match[] = {
 270         { .compatible = "snps,designware-i2c", },
 271         {},
 272 };
 273 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 274 #endif
 275
 276 #ifdef CONFIG_PM_SLEEP
 277 static int dw_i2c_plat_prepare(struct device *dev)
 278 {
 279         return pm_runtime_suspended(dev);
 280 }
 281
 282 static void dw_i2c_plat_complete(struct device *dev)
 283 {
 284         if (dev->power.direct_complete)
 285                 pm_request_resume(dev);
 286 }
 287 #else
 288 #define dw_i2c_plat_prepare     NULL
 289 #define dw_i2c_plat_complete    NULL
 290 #endif
 291
 292 #ifdef CONFIG_PM
 293 static int dw_i2c_plat_suspend(struct device *dev)
 294 {
 295         struct platform_device *pdev = to_platform_device(dev);
 296         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 297
 298         i2c_dw_disable(i_dev);
 299         clk_disable_unprepare(i_dev->clk);
 300
 301         return 0;
 302 }
 303
 304 static int dw_i2c_plat_resume(struct device *dev)
 305 {
 306         struct platform_device *pdev = to_platform_device(dev);
 307         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 308
 309         clk_prepare_enable(i_dev->clk);
 310
 311         if (!i_dev->pm_runtime_disabled)
 312                 i2c_dw_init(i_dev);
 313
 314         return 0;
 315 }
 316
 317 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 318         .prepare = dw_i2c_plat_prepare,
 319         .complete = dw_i2c_plat_complete,
 320         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 321         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 322 };
 323
 324 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 325 #else
 326 #define DW_I2C_DEV_PMOPS NULL
 327 #endif
 328
 329 /* work with hotplug and coldplug */
 330 MODULE_ALIAS("platform:i2c_designware");
 331
 332 static struct platform_driver dw_i2c_driver = {
 333         .probe = dw_i2c_plat_probe,
 334         .remove = dw_i2c_plat_remove,
 335         .driver         = {
 336                 .name   = "i2c_designware",
 337                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 338                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 339                 .pm     = DW_I2C_DEV_PMOPS,
 340         },
 341 };
 342
 343 static int __init dw_i2c_init_driver(void)
 344 {
 345         return platform_driver_register(&dw_i2c_driver);
 346 }
 347 subsys_initcall(dw_i2c_init_driver);
 348
 349 static void __exit dw_i2c_exit_driver(void)
 350 {
 351         platform_driver_unregister(&dw_i2c_driver);
 352 }
 353 module_exit(dw_i2c_exit_driver);
 354
 355 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 356 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 357 MODULE_LICENSE("GPL");