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 <linux/platform_data/i2c-designware.h>
  45 #include "i2c-designware-core.h"
  46
  47 static struct i2c_algorithm i2c_dw_algo = {
  48         .master_xfer    = i2c_dw_xfer,
  49         .functionality  = i2c_dw_func,
  50 };
  51 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  52 {
  53         return clk_get_rate(dev->clk)/1000;
  54 }
  55
  56 #ifdef CONFIG_ACPI
  57 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  58                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  59 {
  60         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  61         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  62         union acpi_object *obj;
  63
  64         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  65                 return;
  66
  67         obj = (union acpi_object *)buf.pointer;
  68         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  69                 const union acpi_object *objs = obj->package.elements;
  70
  71                 *hcnt = (u16)objs[0].integer.value;
  72                 *lcnt = (u16)objs[1].integer.value;
  73                 if (sda_hold)
  74                         *sda_hold = (u32)objs[2].integer.value;
  75         }
  76
  77         kfree(buf.pointer);
  78 }
  79
  80 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  81 {
  82         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  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, NULL);
  96         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
  97                            &dev->sda_hold_time);
  98
  99         return 0;
 100 }
 101
 102 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 103         { "INT33C2", 0 },
 104         { "INT33C3", 0 },
 105         { "INT3432", 0 },
 106         { "INT3433", 0 },
 107         { "80860F41", 0 },
 108         { "808622C1", 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         struct dw_i2c_platform_data *pdata;
 125         int irq, r;
 126         u32 clk_freq;
 127
 128         irq = platform_get_irq(pdev, 0);
 129         if (irq < 0) {
 130                 dev_err(&pdev->dev, "no irq resource?\n");
 131                 return irq; /* -ENXIO */
 132         }
 133
 134         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 135         if (!dev)
 136                 return -ENOMEM;
 137
 138         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 139         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 140         if (IS_ERR(dev->base))
 141                 return PTR_ERR(dev->base);
 142
 143         init_completion(&dev->cmd_complete);
 144         mutex_init(&dev->lock);
 145         dev->dev = &pdev->dev;
 146         dev->irq = irq;
 147         platform_set_drvdata(pdev, dev);
 148
 149         dev->clk = devm_clk_get(&pdev->dev, NULL);
 150         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 151
 152         if (IS_ERR(dev->clk))
 153                 return PTR_ERR(dev->clk);
 154         clk_prepare_enable(dev->clk);
 155
 156         /* fast mode by default because of legacy reasons */
 157         clk_freq = 400000;
 158
 159         if (pdev->dev.of_node) {
 160                 u32 ht = 0;
 161                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 162
 163                 of_property_read_u32(pdev->dev.of_node,
 164                                         "i2c-sda-hold-time-ns", &ht);
 165                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 166                                              1000000);
 167
 168                 of_property_read_u32(pdev->dev.of_node,
 169                                      "i2c-sda-falling-time-ns",
 170                                      &dev->sda_falling_time);
 171                 of_property_read_u32(pdev->dev.of_node,
 172                                      "i2c-scl-falling-time-ns",
 173                                      &dev->scl_falling_time);
 174
 175                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 176                                      &clk_freq);
 177
 178                 /* Only standard mode at 100kHz and fast mode at 400kHz
 179                  * are supported.
 180                  */
 181                 if (clk_freq != 100000 && clk_freq != 400000) {
 182                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
 183                         return -EINVAL;
 184                 }
 185         } else {
 186                 pdata = dev_get_platdata(&pdev->dev);
 187                 if (pdata)
 188                         clk_freq = pdata->i2c_scl_freq;
 189         }
 190
 191         dev->functionality =
 192                 I2C_FUNC_I2C |
 193                 I2C_FUNC_10BIT_ADDR |
 194                 I2C_FUNC_SMBUS_BYTE |
 195                 I2C_FUNC_SMBUS_BYTE_DATA |
 196                 I2C_FUNC_SMBUS_WORD_DATA |
 197                 I2C_FUNC_SMBUS_I2C_BLOCK;
 198         if (clk_freq == 100000)
 199                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 200                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
 201         else
 202                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 203                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 204
 205         /* Try first if we can configure the device from ACPI */
 206         r = dw_i2c_acpi_configure(pdev);
 207         if (r) {
 208                 u32 param1 = i2c_dw_read_comp_param(dev);
 209
 210                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 211                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 212                 dev->adapter.nr = pdev->id;
 213         }
 214         r = i2c_dw_init(dev);
 215         if (r)
 216                 return r;
 217
 218         i2c_dw_disable_int(dev);
 219         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
 220                         pdev->name, dev);
 221         if (r) {
 222                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 223                 return r;
 224         }
 225
 226         adap = &dev->adapter;
 227         i2c_set_adapdata(adap, dev);
 228         adap->owner = THIS_MODULE;
 229         adap->class = I2C_CLASS_DEPRECATED;
 230         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 231                         sizeof(adap->name));
 232         adap->algo = &i2c_dw_algo;
 233         adap->dev.parent = &pdev->dev;
 234         adap->dev.of_node = pdev->dev.of_node;
 235
 236         r = i2c_add_numbered_adapter(adap);
 237         if (r) {
 238                 dev_err(&pdev->dev, "failure adding adapter\n");
 239                 return r;
 240         }
 241
 242         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 243         pm_runtime_use_autosuspend(&pdev->dev);
 244         pm_runtime_set_active(&pdev->dev);
 245         pm_runtime_enable(&pdev->dev);
 246
 247         return 0;
 248 }
 249
 250 static int dw_i2c_remove(struct platform_device *pdev)
 251 {
 252         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 253
 254         pm_runtime_get_sync(&pdev->dev);
 255
 256         i2c_del_adapter(&dev->adapter);
 257
 258         i2c_dw_disable(dev);
 259
 260         pm_runtime_put(&pdev->dev);
 261         pm_runtime_disable(&pdev->dev);
 262
 263         return 0;
 264 }
 265
 266 #ifdef CONFIG_OF
 267 static const struct of_device_id dw_i2c_of_match[] = {
 268         { .compatible = "snps,designware-i2c", },
 269         {},
 270 };
 271 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 272 #endif
 273
 274 #ifdef CONFIG_PM
 275 static int dw_i2c_suspend(struct device *dev)
 276 {
 277         struct platform_device *pdev = to_platform_device(dev);
 278         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 279
 280         i2c_dw_disable(i_dev);
 281         clk_disable_unprepare(i_dev->clk);
 282
 283         return 0;
 284 }
 285
 286 static int dw_i2c_resume(struct device *dev)
 287 {
 288         struct platform_device *pdev = to_platform_device(dev);
 289         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 290
 291         clk_prepare_enable(i_dev->clk);
 292         i2c_dw_init(i_dev);
 293
 294         return 0;
 295 }
 296 #endif
 297
 298 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
 299                             dw_i2c_resume, NULL);
 300
 301 /* work with hotplug and coldplug */
 302 MODULE_ALIAS("platform:i2c_designware");
 303
 304 static struct platform_driver dw_i2c_driver = {
 305         .probe = dw_i2c_probe,
 306         .remove = dw_i2c_remove,
 307         .driver         = {
 308                 .name   = "i2c_designware",
 309                 .owner  = THIS_MODULE,
 310                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 311                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 312                 .pm     = &dw_i2c_dev_pm_ops,
 313         },
 314 };
 315
 316 static int __init dw_i2c_init_driver(void)
 317 {
 318         return platform_driver_register(&dw_i2c_driver);
 319 }
 320 subsys_initcall(dw_i2c_init_driver);
 321
 322 static void __exit dw_i2c_exit_driver(void)
 323 {
 324         platform_driver_unregister(&dw_i2c_driver);
 325 }
 326 module_exit(dw_i2c_exit_driver);
 327
 328 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 329 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 330 MODULE_LICENSE("GPL");