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/errno.h>
  34 #include <linux/sched.h>
  35 #include <linux/err.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/of.h>
  38 #include <linux/platform_device.h>
  39 #include <linux/pm.h>
  40 #include <linux/pm_runtime.h>
  41 #include <linux/io.h>
  42 #include <linux/slab.h>
  43 #include <linux/acpi.h>
  44 #include "i2c-designware-core.h"
  45
  46 static struct i2c_algorithm i2c_dw_algo = {
  47         .master_xfer    = i2c_dw_xfer,
  48         .functionality  = i2c_dw_func,
  49 };
  50 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  51 {
  52         return clk_get_rate(dev->clk)/1000;
  53 }
  54
  55 #ifdef CONFIG_ACPI
  56 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  57                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  58 {
  59         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  60         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  61         union acpi_object *obj;
  62
  63         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  64                 return;
  65
  66         obj = (union acpi_object *)buf.pointer;
  67         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  68                 const union acpi_object *objs = obj->package.elements;
  69
  70                 *hcnt = (u16)objs[0].integer.value;
  71                 *lcnt = (u16)objs[1].integer.value;
  72                 if (sda_hold)
  73                         *sda_hold = (u32)objs[2].integer.value;
  74         }
  75
  76         kfree(buf.pointer);
  77 }
  78
  79 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  80 {
  81         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  82         bool fs_mode = dev->master_cfg & DW_IC_CON_SPEED_FAST;
  83
  84         if (!ACPI_HANDLE(&pdev->dev))
  85                 return -ENODEV;
  86
  87         dev->adapter.nr = -1;
  88         dev->tx_fifo_depth = 32;
  89         dev->rx_fifo_depth = 32;
  90
  91         /*
  92          * Try to get SDA hold time and *CNT values from an ACPI method if
  93          * it exists for both supported speed modes.
  94          */
  95         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt,
  96                            fs_mode ? NULL : &dev->sda_hold_time);
  97         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
  98                            fs_mode ? &dev->sda_hold_time : NULL);
  99
 100         return 0;
 101 }
 102
 103 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 104         { "INT33C2", 0 },
 105         { "INT33C3", 0 },
 106         { "INT3432", 0 },
 107         { "INT3433", 0 },
 108         { "80860F41", 0 },
 109         { }
 110 };
 111 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 112 #else
 113 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 114 {
 115         return -ENODEV;
 116 }
 117 #endif
 118
 119 static int dw_i2c_probe(struct platform_device *pdev)
 120 {
 121         struct dw_i2c_dev *dev;
 122         struct i2c_adapter *adap;
 123         struct resource *mem;
 124         int irq, r;
 125         u32 bus_rate = DW_IC_CON_SPEED_STD;
 126
 127         irq = platform_get_irq(pdev, 0);
 128         if (irq < 0) {
 129                 dev_err(&pdev->dev, "no irq resource?\n");
 130                 return irq; /* -ENXIO */
 131         }
 132
 133         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 134         if (!dev)
 135                 return -ENOMEM;
 136
 137         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 138         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 139         if (IS_ERR(dev->base))
 140                 return PTR_ERR(dev->base);
 141
 142         init_completion(&dev->cmd_complete);
 143         mutex_init(&dev->lock);
 144         dev->dev = &pdev->dev;
 145         dev->irq = irq;
 146         platform_set_drvdata(pdev, dev);
 147
 148         dev->clk = devm_clk_get(&pdev->dev, NULL);
 149         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 150
 151         if (IS_ERR(dev->clk))
 152                 return PTR_ERR(dev->clk);
 153         clk_prepare_enable(dev->clk);
 154
 155         if (pdev->dev.of_node) {
 156                 u32 ht = 0;
 157                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 158
 159                 of_property_read_u32(pdev->dev.of_node,
 160                                         "i2c-sda-hold-time-ns", &ht);
 161                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 162                                              1000000);
 163
 164                 of_property_read_u32(pdev->dev.of_node,
 165                                      "i2c-sda-falling-time-ns",
 166                                      &dev->sda_falling_time);
 167                 of_property_read_u32(pdev->dev.of_node,
 168                                      "i2c-scl-falling-time-ns",
 169                                      &dev->scl_falling_time);
 170
 171                 r = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 172                                                 &bus_rate);
 173                 if (r)
 174                         bus_rate = 400000; /* default clock rate */
 175                 switch (bus_rate) {
 176                 case 400000:
 177                         bus_rate = DW_IC_CON_SPEED_FAST;
 178                         break;
 179                 case 100000:
 180                         bus_rate = DW_IC_CON_SPEED_STD;
 181                         break;
 182                 default:
 183                         dev_err(&pdev->dev, "Invalid bus speed (not 100kHz or 400kHz)\n");
 184                         return -EINVAL;
 185                 }
 186         }
 187
 188         dev->functionality =
 189                 I2C_FUNC_I2C |
 190                 I2C_FUNC_10BIT_ADDR |
 191                 I2C_FUNC_SMBUS_BYTE |
 192                 I2C_FUNC_SMBUS_BYTE_DATA |
 193                 I2C_FUNC_SMBUS_WORD_DATA |
 194                 I2C_FUNC_SMBUS_I2C_BLOCK;
 195         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 196                 DW_IC_CON_RESTART_EN | bus_rate;
 197
 198         /* Try first if we can configure the device from ACPI */
 199         r = dw_i2c_acpi_configure(pdev);
 200         if (r) {
 201                 u32 param1 = i2c_dw_read_comp_param(dev);
 202
 203                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 204                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 205                 dev->adapter.nr = pdev->id;
 206         }
 207         r = i2c_dw_init(dev);
 208         if (r)
 209                 return r;
 210
 211         i2c_dw_disable_int(dev);
 212         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
 213                         pdev->name, dev);
 214         if (r) {
 215                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 216                 return r;
 217         }
 218
 219         adap = &dev->adapter;
 220         i2c_set_adapdata(adap, dev);
 221         adap->owner = THIS_MODULE;
 222         adap->class = I2C_CLASS_HWMON | I2C_CLASS_DEPRECATED;
 223         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 224                         sizeof(adap->name));
 225         adap->algo = &i2c_dw_algo;
 226         adap->dev.parent = &pdev->dev;
 227         adap->dev.of_node = pdev->dev.of_node;
 228
 229         r = i2c_add_numbered_adapter(adap);
 230         if (r) {
 231                 dev_err(&pdev->dev, "failure adding adapter\n");
 232                 return r;
 233         }
 234
 235         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 236         pm_runtime_use_autosuspend(&pdev->dev);
 237         pm_runtime_set_active(&pdev->dev);
 238         pm_runtime_enable(&pdev->dev);
 239
 240         return 0;
 241 }
 242
 243 static int dw_i2c_remove(struct platform_device *pdev)
 244 {
 245         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 246
 247         pm_runtime_get_sync(&pdev->dev);
 248
 249         i2c_del_adapter(&dev->adapter);
 250
 251         i2c_dw_disable(dev);
 252
 253         pm_runtime_put(&pdev->dev);
 254         pm_runtime_disable(&pdev->dev);
 255
 256         return 0;
 257 }
 258
 259 #ifdef CONFIG_OF
 260 static const struct of_device_id dw_i2c_of_match[] = {
 261         { .compatible = "snps,designware-i2c", },
 262         {},
 263 };
 264 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 265 #endif
 266
 267 #ifdef CONFIG_PM_SLEEP
 268 static int dw_i2c_suspend(struct device *dev)
 269 {
 270         struct platform_device *pdev = to_platform_device(dev);
 271         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 272
 273         clk_disable_unprepare(i_dev->clk);
 274
 275         return 0;
 276 }
 277
 278 static int dw_i2c_resume(struct device *dev)
 279 {
 280         struct platform_device *pdev = to_platform_device(dev);
 281         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 282
 283         clk_prepare_enable(i_dev->clk);
 284         i2c_dw_init(i_dev);
 285
 286         return 0;
 287 }
 288
 289 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
 290 #define DW_I2C_DEV_PM_OPS       (&dw_i2c_dev_pm_ops)
 291 #else
 292 #define DW_I2C_DEV_PM_OPS       NULL
 293 #endif
 294
 295 /* work with hotplug and coldplug */
 296 MODULE_ALIAS("platform:i2c_designware");
 297
 298 static struct platform_driver dw_i2c_driver = {
 299         .probe = dw_i2c_probe,
 300         .remove = dw_i2c_remove,
 301         .driver         = {
 302                 .name   = "i2c_designware",
 303                 .owner  = THIS_MODULE,
 304                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 305                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 306                 .pm     = DW_I2C_DEV_PM_OPS,
 307         },
 308 };
 309
 310 static int __init dw_i2c_init_driver(void)
 311 {
 312         return platform_driver_register(&dw_i2c_driver);
 313 }
 314 subsys_initcall(dw_i2c_init_driver);
 315
 316 static void __exit dw_i2c_exit_driver(void)
 317 {
 318         platform_driver_unregister(&dw_i2c_driver);
 319 }
 320 module_exit(dw_i2c_exit_driver);
 321
 322 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 323 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 324 MODULE_LICENSE("GPL");