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         { "AMDI0010", ACCESS_INTR_MASK },
 127         { "AMDI0510", 0 },
 128         { "APMC0D0F", 0 },
 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 #endif
 138
 139 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 140 {
 141         if (IS_ERR(i_dev->clk))
 142                 return PTR_ERR(i_dev->clk);
 143
 144         if (prepare)
 145                 return clk_prepare_enable(i_dev->clk);
 146
 147         clk_disable_unprepare(i_dev->clk);
 148         return 0;
 149 }
 150
 151 static int dw_i2c_plat_probe(struct platform_device *pdev)
 152 {
 153         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 154         struct dw_i2c_dev *dev;
 155         struct i2c_adapter *adap;
 156         struct resource *mem;
 157         int irq, r;
 158         u32 clk_freq, ht = 0;
 159
 160         irq = platform_get_irq(pdev, 0);
 161         if (irq < 0)
 162                 return irq;
 163
 164         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 165         if (!dev)
 166                 return -ENOMEM;
 167
 168         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 169         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 170         if (IS_ERR(dev->base))
 171                 return PTR_ERR(dev->base);
 172
 173         dev->dev = &pdev->dev;
 174         dev->irq = irq;
 175         platform_set_drvdata(pdev, dev);
 176
 177         /* fast mode by default because of legacy reasons */
 178         clk_freq = 400000;
 179
 180         if (pdata) {
 181                 clk_freq = pdata->i2c_scl_freq;
 182         } else {
 183                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 184                                          &ht);
 185                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 186                                          &dev->sda_falling_time);
 187                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 188                                          &dev->scl_falling_time);
 189                 device_property_read_u32(&pdev->dev, "clock-frequency",
 190                                          &clk_freq);
 191         }
 192
 193         if (has_acpi_companion(&pdev->dev))
 194                 dw_i2c_acpi_configure(pdev);
 195
 196         /*
 197          * Only standard mode at 100kHz and fast mode at 400kHz are supported.
 198          */
 199         if (clk_freq != 100000 && clk_freq != 400000) {
 200                 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 201                 return -EINVAL;
 202         }
 203
 204         r = i2c_dw_eval_lock_support(dev);
 205         if (r)
 206                 return r;
 207
 208         dev->functionality =
 209                 I2C_FUNC_I2C |
 210                 I2C_FUNC_10BIT_ADDR |
 211                 I2C_FUNC_SMBUS_BYTE |
 212                 I2C_FUNC_SMBUS_BYTE_DATA |
 213                 I2C_FUNC_SMBUS_WORD_DATA |
 214                 I2C_FUNC_SMBUS_I2C_BLOCK;
 215         if (clk_freq == 100000)
 216                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 217                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 218         else
 219                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 220                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 221
 222         dev->clk = devm_clk_get(&pdev->dev, NULL);
 223         if (!i2c_dw_plat_prepare_clk(dev, true)) {
 224                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 225
 226                 if (!dev->sda_hold_time && ht)
 227                         dev->sda_hold_time = div_u64(
 228                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 229                                 1000000);
 230         }
 231
 232         if (!dev->tx_fifo_depth) {
 233                 u32 param1 = i2c_dw_read_comp_param(dev);
 234
 235                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 236                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 237                 dev->adapter.nr = pdev->id;
 238         }
 239
 240         adap = &dev->adapter;
 241         adap->owner = THIS_MODULE;
 242         adap->class = I2C_CLASS_DEPRECATED;
 243         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 244         adap->dev.of_node = pdev->dev.of_node;
 245
 246         if (dev->pm_runtime_disabled) {
 247                 pm_runtime_forbid(&pdev->dev);
 248         } else {
 249                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 250                 pm_runtime_use_autosuspend(&pdev->dev);
 251                 pm_runtime_set_active(&pdev->dev);
 252                 pm_runtime_enable(&pdev->dev);
 253         }
 254
 255         r = i2c_dw_probe(dev);
 256         if (r && !dev->pm_runtime_disabled)
 257                 pm_runtime_disable(&pdev->dev);
 258
 259         return r;
 260 }
 261
 262 static int dw_i2c_plat_remove(struct platform_device *pdev)
 263 {
 264         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 265
 266         pm_runtime_get_sync(&pdev->dev);
 267
 268         i2c_del_adapter(&dev->adapter);
 269
 270         i2c_dw_disable(dev);
 271
 272         pm_runtime_dont_use_autosuspend(&pdev->dev);
 273         pm_runtime_put_sync(&pdev->dev);
 274         if (!dev->pm_runtime_disabled)
 275                 pm_runtime_disable(&pdev->dev);
 276
 277         return 0;
 278 }
 279
 280 #ifdef CONFIG_OF
 281 static const struct of_device_id dw_i2c_of_match[] = {
 282         { .compatible = "snps,designware-i2c", },
 283         {},
 284 };
 285 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 286 #endif
 287
 288 #ifdef CONFIG_PM_SLEEP
 289 static int dw_i2c_plat_prepare(struct device *dev)
 290 {
 291         return pm_runtime_suspended(dev);
 292 }
 293
 294 static void dw_i2c_plat_complete(struct device *dev)
 295 {
 296         if (dev->power.direct_complete)
 297                 pm_request_resume(dev);
 298 }
 299 #else
 300 #define dw_i2c_plat_prepare     NULL
 301 #define dw_i2c_plat_complete    NULL
 302 #endif
 303
 304 #ifdef CONFIG_PM
 305 static int dw_i2c_plat_suspend(struct device *dev)
 306 {
 307         struct platform_device *pdev = to_platform_device(dev);
 308         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 309
 310         i2c_dw_disable(i_dev);
 311         i2c_dw_plat_prepare_clk(i_dev, false);
 312
 313         return 0;
 314 }
 315
 316 static int dw_i2c_plat_resume(struct device *dev)
 317 {
 318         struct platform_device *pdev = to_platform_device(dev);
 319         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 320
 321         i2c_dw_plat_prepare_clk(i_dev, true);
 322
 323         if (!i_dev->pm_runtime_disabled)
 324                 i2c_dw_init(i_dev);
 325
 326         return 0;
 327 }
 328
 329 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 330         .prepare = dw_i2c_plat_prepare,
 331         .complete = dw_i2c_plat_complete,
 332         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 333         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 334 };
 335
 336 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 337 #else
 338 #define DW_I2C_DEV_PMOPS NULL
 339 #endif
 340
 341 /* work with hotplug and coldplug */
 342 MODULE_ALIAS("platform:i2c_designware");
 343
 344 static struct platform_driver dw_i2c_driver = {
 345         .probe = dw_i2c_plat_probe,
 346         .remove = dw_i2c_plat_remove,
 347         .driver         = {
 348                 .name   = "i2c_designware",
 349                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 350                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 351                 .pm     = DW_I2C_DEV_PMOPS,
 352         },
 353 };
 354
 355 static int __init dw_i2c_init_driver(void)
 356 {
 357         return platform_driver_register(&dw_i2c_driver);
 358 }
 359 subsys_initcall(dw_i2c_init_driver);
 360
 361 static void __exit dw_i2c_exit_driver(void)
 362 {
 363         platform_driver_unregister(&dw_i2c_driver);
 364 }
 365 module_exit(dw_i2c_exit_driver);
 366
 367 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 368 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 369 MODULE_LICENSE("GPL");