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
  77         dev->adapter.nr = -1;
  78         dev->tx_fifo_depth = 32;
  79         dev->rx_fifo_depth = 32;
  80
  81         /*
  82          * Try to get SDA hold time and *CNT values from an ACPI method if
  83          * it exists for both supported speed modes.
  84          */
  85         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
  86         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
  87                            &dev->sda_hold_time);
  88
  89         return 0;
  90 }
  91
  92 static const struct acpi_device_id dw_i2c_acpi_match[] = {
  93         { "INT33C2", 0 },
  94         { "INT33C3", 0 },
  95         { "INT3432", 0 },
  96         { "INT3433", 0 },
  97         { "80860F41", 0 },
  98         { "808622C1", 0 },
  99         { "AMD0010", 0 },
 100         { }
 101 };
 102 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 103 #else
 104 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 105 {
 106         return -ENODEV;
 107 }
 108 #endif
 109
 110 static int dw_i2c_plat_probe(struct platform_device *pdev)
 111 {
 112         struct dw_i2c_dev *dev;
 113         struct i2c_adapter *adap;
 114         struct resource *mem;
 115         struct dw_i2c_platform_data *pdata;
 116         int irq, r;
 117         u32 clk_freq, ht = 0;
 118
 119         irq = platform_get_irq(pdev, 0);
 120         if (irq < 0)
 121                 return irq;
 122
 123         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 124         if (!dev)
 125                 return -ENOMEM;
 126
 127         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 128         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 129         if (IS_ERR(dev->base))
 130                 return PTR_ERR(dev->base);
 131
 132         dev->dev = &pdev->dev;
 133         dev->irq = irq;
 134         platform_set_drvdata(pdev, dev);
 135
 136         /* fast mode by default because of legacy reasons */
 137         clk_freq = 400000;
 138
 139         if (has_acpi_companion(&pdev->dev)) {
 140                 dw_i2c_acpi_configure(pdev);
 141         } else if (pdev->dev.of_node) {
 142                 of_property_read_u32(pdev->dev.of_node,
 143                                         "i2c-sda-hold-time-ns", &ht);
 144
 145                 of_property_read_u32(pdev->dev.of_node,
 146                                      "i2c-sda-falling-time-ns",
 147                                      &dev->sda_falling_time);
 148                 of_property_read_u32(pdev->dev.of_node,
 149                                      "i2c-scl-falling-time-ns",
 150                                      &dev->scl_falling_time);
 151
 152                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 153                                      &clk_freq);
 154
 155                 /* Only standard mode at 100kHz and fast mode at 400kHz
 156                  * are supported.
 157                  */
 158                 if (clk_freq != 100000 && clk_freq != 400000) {
 159                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 160                         return -EINVAL;
 161                 }
 162         } else {
 163                 pdata = dev_get_platdata(&pdev->dev);
 164                 if (pdata)
 165                         clk_freq = pdata->i2c_scl_freq;
 166         }
 167
 168         r = i2c_dw_eval_lock_support(dev);
 169         if (r)
 170                 return r;
 171
 172         dev->functionality =
 173                 I2C_FUNC_I2C |
 174                 I2C_FUNC_10BIT_ADDR |
 175                 I2C_FUNC_SMBUS_BYTE |
 176                 I2C_FUNC_SMBUS_BYTE_DATA |
 177                 I2C_FUNC_SMBUS_WORD_DATA |
 178                 I2C_FUNC_SMBUS_I2C_BLOCK;
 179         if (clk_freq == 100000)
 180                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 181                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 182         else
 183                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 184                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 185
 186         dev->clk = devm_clk_get(&pdev->dev, NULL);
 187         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 188         if (IS_ERR(dev->clk))
 189                 return PTR_ERR(dev->clk);
 190         clk_prepare_enable(dev->clk);
 191
 192         if (!dev->sda_hold_time && ht) {
 193                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 194
 195                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 196                                              1000000);
 197         }
 198
 199         if (!dev->tx_fifo_depth) {
 200                 u32 param1 = i2c_dw_read_comp_param(dev);
 201
 202                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 203                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 204                 dev->adapter.nr = pdev->id;
 205         }
 206
 207         adap = &dev->adapter;
 208         adap->owner = THIS_MODULE;
 209         adap->class = I2C_CLASS_DEPRECATED;
 210         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 211         adap->dev.of_node = pdev->dev.of_node;
 212
 213         r = i2c_dw_probe(dev);
 214         if (r)
 215                 return r;
 216
 217         if (dev->pm_runtime_disabled) {
 218                 pm_runtime_forbid(&pdev->dev);
 219         } else {
 220                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 221                 pm_runtime_use_autosuspend(&pdev->dev);
 222                 pm_runtime_set_active(&pdev->dev);
 223                 pm_runtime_enable(&pdev->dev);
 224         }
 225
 226         return 0;
 227 }
 228
 229 static int dw_i2c_plat_remove(struct platform_device *pdev)
 230 {
 231         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 232
 233         pm_runtime_get_sync(&pdev->dev);
 234
 235         i2c_del_adapter(&dev->adapter);
 236
 237         i2c_dw_disable(dev);
 238
 239         pm_runtime_dont_use_autosuspend(&pdev->dev);
 240         pm_runtime_put_sync(&pdev->dev);
 241         pm_runtime_disable(&pdev->dev);
 242
 243         return 0;
 244 }
 245
 246 #ifdef CONFIG_OF
 247 static const struct of_device_id dw_i2c_of_match[] = {
 248         { .compatible = "snps,designware-i2c", },
 249         {},
 250 };
 251 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 252 #endif
 253
 254 #ifdef CONFIG_PM_SLEEP
 255 static int dw_i2c_plat_prepare(struct device *dev)
 256 {
 257         return pm_runtime_suspended(dev);
 258 }
 259
 260 static void dw_i2c_plat_complete(struct device *dev)
 261 {
 262         if (dev->power.direct_complete)
 263                 pm_request_resume(dev);
 264 }
 265 #else
 266 #define dw_i2c_plat_prepare     NULL
 267 #define dw_i2c_plat_complete    NULL
 268 #endif
 269
 270 #ifdef CONFIG_PM
 271 static int dw_i2c_plat_suspend(struct device *dev)
 272 {
 273         struct platform_device *pdev = to_platform_device(dev);
 274         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 275
 276         i2c_dw_disable(i_dev);
 277         clk_disable_unprepare(i_dev->clk);
 278
 279         return 0;
 280 }
 281
 282 static int dw_i2c_plat_resume(struct device *dev)
 283 {
 284         struct platform_device *pdev = to_platform_device(dev);
 285         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 286
 287         clk_prepare_enable(i_dev->clk);
 288
 289         if (!i_dev->pm_runtime_disabled)
 290                 i2c_dw_init(i_dev);
 291
 292         return 0;
 293 }
 294
 295 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 296         .prepare = dw_i2c_plat_prepare,
 297         .complete = dw_i2c_plat_complete,
 298         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 299         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 300 };
 301
 302 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 303 #else
 304 #define DW_I2C_DEV_PMOPS NULL
 305 #endif
 306
 307 /* work with hotplug and coldplug */
 308 MODULE_ALIAS("platform:i2c_designware");
 309
 310 static struct platform_driver dw_i2c_driver = {
 311         .probe = dw_i2c_plat_probe,
 312         .remove = dw_i2c_plat_remove,
 313         .driver         = {
 314                 .name   = "i2c_designware",
 315                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 316                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 317                 .pm     = DW_I2C_DEV_PMOPS,
 318         },
 319 };
 320
 321 static int __init dw_i2c_init_driver(void)
 322 {
 323         return platform_driver_register(&dw_i2c_driver);
 324 }
 325 subsys_initcall(dw_i2c_init_driver);
 326
 327 static void __exit dw_i2c_exit_driver(void)
 328 {
 329         platform_driver_unregister(&dw_i2c_driver);
 330 }
 331 module_exit(dw_i2c_exit_driver);
 332
 333 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 334 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 335 MODULE_LICENSE("GPL");