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