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  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  * ----------------------------------------------------------------------------
  26  *
  27  */
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/delay.h>
  31 #include <linux/i2c.h>
  32 #include <linux/clk.h>
  33 #include <linux/clk-provider.h>
  34 #include <linux/errno.h>
  35 #include <linux/sched.h>
  36 #include <linux/err.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/of.h>
  39 #include <linux/platform_device.h>
  40 #include <linux/pm.h>
  41 #include <linux/pm_runtime.h>
  42 #include <linux/io.h>
  43 #include <linux/slab.h>
  44 #include <linux/acpi.h>
  45 #include <linux/platform_data/i2c-designware.h>
  46 #include "i2c-designware-core.h"
  47
  48 static struct i2c_algorithm i2c_dw_algo = {
  49         .master_xfer    = i2c_dw_xfer,
  50         .functionality  = i2c_dw_func,
  51 };
  52 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  53 {
  54         return clk_get_rate(dev->clk)/1000;
  55 }
  56
  57 #ifdef CONFIG_ACPI
  58 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  59                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  60 {
  61         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  62         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  63         union acpi_object *obj;
  64
  65         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  66                 return;
  67
  68         obj = (union acpi_object *)buf.pointer;
  69         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  70                 const union acpi_object *objs = obj->package.elements;
  71
  72                 *hcnt = (u16)objs[0].integer.value;
  73                 *lcnt = (u16)objs[1].integer.value;
  74                 if (sda_hold)
  75                         *sda_hold = (u32)objs[2].integer.value;
  76         }
  77
  78         kfree(buf.pointer);
  79 }
  80
  81 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  82 {
  83         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  84         const struct acpi_device_id *id;
  85
  86         dev->adapter.nr = -1;
  87         dev->tx_fifo_depth = 32;
  88         dev->rx_fifo_depth = 32;
  89
  90         /*
  91          * Try to get SDA hold time and *CNT values from an ACPI method if
  92          * it exists for both supported speed modes.
  93          */
  94         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
  95         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
  96                            &dev->sda_hold_time);
  97
  98         /*
  99          * Provide a way for Designware I2C host controllers that are not
 100          * based on Intel LPSS to specify their input clock frequency via
 101          * id->driver_data.
 102          */
 103         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 104         if (id && id->driver_data)
 105                 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
 106                                         CLK_IS_ROOT, id->driver_data);
 107
 108         return 0;
 109 }
 110
 111 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
 112 {
 113         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 114         const struct acpi_device_id *id;
 115
 116         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 117         if (id && id->driver_data)
 118                 clk_unregister(dev->clk);
 119 }
 120
 121 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 122         { "INT33C2", 0 },
 123         { "INT33C3", 0 },
 124         { "INT3432", 0 },
 125         { "INT3433", 0 },
 126         { "80860F41", 0 },
 127         { "808622C1", 0 },
 128         { "AMD0010", 133 * 1000 * 1000 },
 129         { }
 130 };
 131 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 132 #else
 133 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 134 {
 135         return -ENODEV;
 136 }
 137 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
 138 #endif
 139
 140 static int dw_i2c_probe(struct platform_device *pdev)
 141 {
 142         struct dw_i2c_dev *dev;
 143         struct i2c_adapter *adap;
 144         struct resource *mem;
 145         struct dw_i2c_platform_data *pdata;
 146         int irq, r;
 147         u32 clk_freq, ht = 0;
 148
 149         irq = platform_get_irq(pdev, 0);
 150         if (irq < 0) {
 151                 dev_err(&pdev->dev, "no irq resource?\n");
 152                 return irq; /* -ENXIO */
 153         }
 154
 155         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 156         if (!dev)
 157                 return -ENOMEM;
 158
 159         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 160         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 161         if (IS_ERR(dev->base))
 162                 return PTR_ERR(dev->base);
 163
 164         init_completion(&dev->cmd_complete);
 165         mutex_init(&dev->lock);
 166         dev->dev = &pdev->dev;
 167         dev->irq = irq;
 168         platform_set_drvdata(pdev, dev);
 169
 170         /* fast mode by default because of legacy reasons */
 171         clk_freq = 400000;
 172
 173         if (ACPI_COMPANION(&pdev->dev)) {
 174                 dw_i2c_acpi_configure(pdev);
 175         } else if (pdev->dev.of_node) {
 176                 of_property_read_u32(pdev->dev.of_node,
 177                                         "i2c-sda-hold-time-ns", &ht);
 178
 179                 of_property_read_u32(pdev->dev.of_node,
 180                                      "i2c-sda-falling-time-ns",
 181                                      &dev->sda_falling_time);
 182                 of_property_read_u32(pdev->dev.of_node,
 183                                      "i2c-scl-falling-time-ns",
 184                                      &dev->scl_falling_time);
 185
 186                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 187                                      &clk_freq);
 188
 189                 /* Only standard mode at 100kHz and fast mode at 400kHz
 190                  * are supported.
 191                  */
 192                 if (clk_freq != 100000 && clk_freq != 400000) {
 193                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 194                         return -EINVAL;
 195                 }
 196         } else {
 197                 pdata = dev_get_platdata(&pdev->dev);
 198                 if (pdata)
 199                         clk_freq = pdata->i2c_scl_freq;
 200         }
 201
 202         dev->functionality =
 203                 I2C_FUNC_I2C |
 204                 I2C_FUNC_10BIT_ADDR |
 205                 I2C_FUNC_SMBUS_BYTE |
 206                 I2C_FUNC_SMBUS_BYTE_DATA |
 207                 I2C_FUNC_SMBUS_WORD_DATA |
 208                 I2C_FUNC_SMBUS_I2C_BLOCK;
 209         if (clk_freq == 100000)
 210                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 211                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 212         else
 213                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 214                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 215
 216         dev->clk = devm_clk_get(&pdev->dev, NULL);
 217         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 218         if (IS_ERR(dev->clk))
 219                 return PTR_ERR(dev->clk);
 220         clk_prepare_enable(dev->clk);
 221
 222         if (!dev->sda_hold_time && ht) {
 223                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 224
 225                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 226                                              1000000);
 227         }
 228
 229         if (!dev->tx_fifo_depth) {
 230                 u32 param1 = i2c_dw_read_comp_param(dev);
 231
 232                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 233                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 234                 dev->adapter.nr = pdev->id;
 235         }
 236         r = i2c_dw_init(dev);
 237         if (r)
 238                 return r;
 239
 240         i2c_dw_disable_int(dev);
 241         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
 242                         pdev->name, dev);
 243         if (r) {
 244                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 245                 return r;
 246         }
 247
 248         adap = &dev->adapter;
 249         i2c_set_adapdata(adap, dev);
 250         adap->owner = THIS_MODULE;
 251         adap->class = I2C_CLASS_DEPRECATED;
 252         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 253                         sizeof(adap->name));
 254         adap->algo = &i2c_dw_algo;
 255         adap->dev.parent = &pdev->dev;
 256         adap->dev.of_node = pdev->dev.of_node;
 257
 258         r = i2c_add_numbered_adapter(adap);
 259         if (r) {
 260                 dev_err(&pdev->dev, "failure adding adapter\n");
 261                 return r;
 262         }
 263
 264         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 265         pm_runtime_use_autosuspend(&pdev->dev);
 266         pm_runtime_set_active(&pdev->dev);
 267         pm_runtime_enable(&pdev->dev);
 268
 269         return 0;
 270 }
 271
 272 static int dw_i2c_remove(struct platform_device *pdev)
 273 {
 274         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 275
 276         pm_runtime_get_sync(&pdev->dev);
 277
 278         i2c_del_adapter(&dev->adapter);
 279
 280         i2c_dw_disable(dev);
 281
 282         pm_runtime_put(&pdev->dev);
 283         pm_runtime_disable(&pdev->dev);
 284
 285         if (ACPI_COMPANION(&pdev->dev))
 286                 dw_i2c_acpi_unconfigure(pdev);
 287
 288         return 0;
 289 }
 290
 291 #ifdef CONFIG_OF
 292 static const struct of_device_id dw_i2c_of_match[] = {
 293         { .compatible = "snps,designware-i2c", },
 294         {},
 295 };
 296 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 297 #endif
 298
 299 #ifdef CONFIG_PM
 300 static int dw_i2c_suspend(struct device *dev)
 301 {
 302         struct platform_device *pdev = to_platform_device(dev);
 303         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 304
 305         i2c_dw_disable(i_dev);
 306         clk_disable_unprepare(i_dev->clk);
 307
 308         return 0;
 309 }
 310
 311 static int dw_i2c_resume(struct device *dev)
 312 {
 313         struct platform_device *pdev = to_platform_device(dev);
 314         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 315
 316         clk_prepare_enable(i_dev->clk);
 317         i2c_dw_init(i_dev);
 318
 319         return 0;
 320 }
 321 #endif
 322
 323 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
 324                             dw_i2c_resume, NULL);
 325
 326 /* work with hotplug and coldplug */
 327 MODULE_ALIAS("platform:i2c_designware");
 328
 329 static struct platform_driver dw_i2c_driver = {
 330         .probe = dw_i2c_probe,
 331         .remove = dw_i2c_remove,
 332         .driver         = {
 333                 .name   = "i2c_designware",
 334                 .owner  = THIS_MODULE,
 335                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 336                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 337                 .pm     = &dw_i2c_dev_pm_ops,
 338         },
 339 };
 340
 341 static int __init dw_i2c_init_driver(void)
 342 {
 343         return platform_driver_register(&dw_i2c_driver);
 344 }
 345 subsys_initcall(dw_i2c_init_driver);
 346
 347 static void __exit dw_i2c_exit_driver(void)
 348 {
 349         platform_driver_unregister(&dw_i2c_driver);
 350 }
 351 module_exit(dw_i2c_exit_driver);
 352
 353 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 354 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 355 MODULE_LICENSE("GPL");