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/i2c.h>
  28 #include <linux/clk.h>
  29 #include <linux/clk-provider.h>
  30 #include <linux/errno.h>
  31 #include <linux/sched.h>
  32 #include <linux/err.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/of.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/pm.h>
  37 #include <linux/pm_runtime.h>
  38 #include <linux/io.h>
  39 #include <linux/slab.h>
  40 #include <linux/acpi.h>
  41 #include <linux/platform_data/i2c-designware.h>
  42 #include "i2c-designware-core.h"
  43
  44 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  45 {
  46         return clk_get_rate(dev->clk)/1000;
  47 }
  48
  49 #ifdef CONFIG_ACPI
  50 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  51                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  52 {
  53         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  54         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  55         union acpi_object *obj;
  56
  57         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  58                 return;
  59
  60         obj = (union acpi_object *)buf.pointer;
  61         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  62                 const union acpi_object *objs = obj->package.elements;
  63
  64                 *hcnt = (u16)objs[0].integer.value;
  65                 *lcnt = (u16)objs[1].integer.value;
  66                 if (sda_hold)
  67                         *sda_hold = (u32)objs[2].integer.value;
  68         }
  69
  70         kfree(buf.pointer);
  71 }
  72
  73 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  74 {
  75         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  76         const struct acpi_device_id *id;
  77
  78         dev->adapter.nr = -1;
  79         dev->tx_fifo_depth = 32;
  80         dev->rx_fifo_depth = 32;
  81
  82         /*
  83          * Try to get SDA hold time and *CNT values from an ACPI method if
  84          * it exists for both supported speed modes.
  85          */
  86         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
  87         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
  88                            &dev->sda_hold_time);
  89
  90         /*
  91          * Provide a way for Designware I2C host controllers that are not
  92          * based on Intel LPSS to specify their input clock frequency via
  93          * id->driver_data.
  94          */
  95         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
  96         if (id && id->driver_data)
  97                 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
  98                                         CLK_IS_ROOT, id->driver_data);
  99
 100         return 0;
 101 }
 102
 103 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
 104 {
 105         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 106         const struct acpi_device_id *id;
 107
 108         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 109         if (id && id->driver_data)
 110                 clk_unregister(dev->clk);
 111 }
 112
 113 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 114         { "INT33C2", 0 },
 115         { "INT33C3", 0 },
 116         { "INT3432", 0 },
 117         { "INT3433", 0 },
 118         { "80860F41", 0 },
 119         { "808622C1", 0 },
 120         { "AMD0010", 133 * 1000 * 1000 },
 121         { }
 122 };
 123 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 124 #else
 125 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 126 {
 127         return -ENODEV;
 128 }
 129 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
 130 #endif
 131
 132 static int dw_i2c_plat_probe(struct platform_device *pdev)
 133 {
 134         struct dw_i2c_dev *dev;
 135         struct i2c_adapter *adap;
 136         struct resource *mem;
 137         struct dw_i2c_platform_data *pdata;
 138         int irq, r;
 139         u32 clk_freq, ht = 0;
 140
 141         irq = platform_get_irq(pdev, 0);
 142         if (irq < 0)
 143                 return irq;
 144
 145         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 146         if (!dev)
 147                 return -ENOMEM;
 148
 149         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 150         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 151         if (IS_ERR(dev->base))
 152                 return PTR_ERR(dev->base);
 153
 154         dev->dev = &pdev->dev;
 155         dev->irq = irq;
 156         platform_set_drvdata(pdev, dev);
 157
 158         /* fast mode by default because of legacy reasons */
 159         clk_freq = 400000;
 160
 161         if (has_acpi_companion(&pdev->dev)) {
 162                 dw_i2c_acpi_configure(pdev);
 163         } else if (pdev->dev.of_node) {
 164                 of_property_read_u32(pdev->dev.of_node,
 165                                         "i2c-sda-hold-time-ns", &ht);
 166
 167                 of_property_read_u32(pdev->dev.of_node,
 168                                      "i2c-sda-falling-time-ns",
 169                                      &dev->sda_falling_time);
 170                 of_property_read_u32(pdev->dev.of_node,
 171                                      "i2c-scl-falling-time-ns",
 172                                      &dev->scl_falling_time);
 173
 174                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 175                                      &clk_freq);
 176
 177                 /* Only standard mode at 100kHz and fast mode at 400kHz
 178                  * are supported.
 179                  */
 180                 if (clk_freq != 100000 && clk_freq != 400000) {
 181                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 182                         return -EINVAL;
 183                 }
 184         } else {
 185                 pdata = dev_get_platdata(&pdev->dev);
 186                 if (pdata)
 187                         clk_freq = pdata->i2c_scl_freq;
 188         }
 189
 190         r = i2c_dw_eval_lock_support(dev);
 191         if (r)
 192                 return r;
 193
 194         dev->functionality =
 195                 I2C_FUNC_I2C |
 196                 I2C_FUNC_10BIT_ADDR |
 197                 I2C_FUNC_SMBUS_BYTE |
 198                 I2C_FUNC_SMBUS_BYTE_DATA |
 199                 I2C_FUNC_SMBUS_WORD_DATA |
 200                 I2C_FUNC_SMBUS_I2C_BLOCK;
 201         if (clk_freq == 100000)
 202                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 203                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 204         else
 205                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 206                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 207
 208         dev->clk = devm_clk_get(&pdev->dev, NULL);
 209         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 210         if (IS_ERR(dev->clk))
 211                 return PTR_ERR(dev->clk);
 212         clk_prepare_enable(dev->clk);
 213
 214         if (!dev->sda_hold_time && ht) {
 215                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 216
 217                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 218                                              1000000);
 219         }
 220
 221         if (!dev->tx_fifo_depth) {
 222                 u32 param1 = i2c_dw_read_comp_param(dev);
 223
 224                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 225                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 226                 dev->adapter.nr = pdev->id;
 227         }
 228
 229         adap = &dev->adapter;
 230         adap->owner = THIS_MODULE;
 231         adap->class = I2C_CLASS_DEPRECATED;
 232         adap->dev.of_node = pdev->dev.of_node;
 233
 234         r = i2c_dw_probe(dev);
 235         if (r)
 236                 return r;
 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         return 0;
 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         pm_runtime_disable(&pdev->dev);
 263
 264         if (has_acpi_companion(&pdev->dev))
 265                 dw_i2c_acpi_unconfigure(pdev);
 266
 267         return 0;
 268 }
 269
 270 #ifdef CONFIG_OF
 271 static const struct of_device_id dw_i2c_of_match[] = {
 272         { .compatible = "snps,designware-i2c", },
 273         {},
 274 };
 275 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 276 #endif
 277
 278 #ifdef CONFIG_PM_SLEEP
 279 static int dw_i2c_plat_prepare(struct device *dev)
 280 {
 281         return pm_runtime_suspended(dev);
 282 }
 283
 284 static void dw_i2c_plat_complete(struct device *dev)
 285 {
 286         if (dev->power.direct_complete)
 287                 pm_request_resume(dev);
 288 }
 289 #else
 290 #define dw_i2c_plat_prepare     NULL
 291 #define dw_i2c_plat_complete    NULL
 292 #endif
 293
 294 #ifdef CONFIG_PM
 295 static int dw_i2c_plat_suspend(struct device *dev)
 296 {
 297         struct platform_device *pdev = to_platform_device(dev);
 298         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 299
 300         i2c_dw_disable(i_dev);
 301         clk_disable_unprepare(i_dev->clk);
 302
 303         return 0;
 304 }
 305
 306 static int dw_i2c_plat_resume(struct device *dev)
 307 {
 308         struct platform_device *pdev = to_platform_device(dev);
 309         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 310
 311         clk_prepare_enable(i_dev->clk);
 312
 313         if (!i_dev->pm_runtime_disabled)
 314                 i2c_dw_init(i_dev);
 315
 316         return 0;
 317 }
 318
 319 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 320         .prepare = dw_i2c_plat_prepare,
 321         .complete = dw_i2c_plat_complete,
 322         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 323         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 324 };
 325
 326 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 327 #else
 328 #define DW_I2C_DEV_PMOPS NULL
 329 #endif
 330
 331 /* work with hotplug and coldplug */
 332 MODULE_ALIAS("platform:i2c_designware");
 333
 334 static struct platform_driver dw_i2c_driver = {
 335         .probe = dw_i2c_plat_probe,
 336         .remove = dw_i2c_plat_remove,
 337         .driver         = {
 338                 .name   = "i2c_designware",
 339                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 340                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 341                 .pm     = DW_I2C_DEV_PMOPS,
 342         },
 343 };
 344
 345 static int __init dw_i2c_init_driver(void)
 346 {
 347         return platform_driver_register(&dw_i2c_driver);
 348 }
 349 subsys_initcall(dw_i2c_init_driver);
 350
 351 static void __exit dw_i2c_exit_driver(void)
 352 {
 353         platform_driver_unregister(&dw_i2c_driver);
 354 }
 355 module_exit(dw_i2c_exit_driver);
 356
 357 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 358 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 359 MODULE_LICENSE("GPL");