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_i2c.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 int dw_i2c_acpi_configure(struct platform_device *pdev)
  57 {
  58         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  59         struct acpi_device *adev;
  60         int busno, ret;
  61
  62         if (!ACPI_HANDLE(&pdev->dev))
  63                 return -ENODEV;
  64
  65         ret = acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev);
  66         if (ret)
  67                 return -ENODEV;
  68
  69         dev->adapter.nr = -1;
  70         if (adev->pnp.unique_id && !kstrtoint(adev->pnp.unique_id, 0, &busno))
  71                 dev->adapter.nr = busno;
  72
  73         dev->tx_fifo_depth = 32;
  74         dev->rx_fifo_depth = 32;
  75         return 0;
  76 }
  77
  78 static const struct acpi_device_id dw_i2c_acpi_match[] = {
  79         { "INT33C2", 0 },
  80         { "INT33C3", 0 },
  81         { }
  82 };
  83 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
  84 #else
  85 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
  86 {
  87         return -ENODEV;
  88 }
  89 #endif
  90
  91 static int dw_i2c_probe(struct platform_device *pdev)
  92 {
  93         struct dw_i2c_dev *dev;
  94         struct i2c_adapter *adap;
  95         struct resource *mem, *ioarea;
  96         int irq, r;
  97
  98         /* NOTE: driver uses the static register mapping */
  99         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 100         if (!mem) {
 101                 dev_err(&pdev->dev, "no mem resource?\n");
 102                 return -EINVAL;
 103         }
 104
 105         irq = platform_get_irq(pdev, 0);
 106         if (irq < 0) {
 107                 dev_err(&pdev->dev, "no irq resource?\n");
 108                 return irq; /* -ENXIO */
 109         }
 110
 111         ioarea = request_mem_region(mem->start, resource_size(mem),
 112                         pdev->name);
 113         if (!ioarea) {
 114                 dev_err(&pdev->dev, "I2C region already claimed\n");
 115                 return -EBUSY;
 116         }
 117
 118         dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
 119         if (!dev) {
 120                 r = -ENOMEM;
 121                 goto err_release_region;
 122         }
 123
 124         init_completion(&dev->cmd_complete);
 125         mutex_init(&dev->lock);
 126         dev->dev = get_device(&pdev->dev);
 127         dev->irq = irq;
 128         platform_set_drvdata(pdev, dev);
 129
 130         dev->clk = clk_get(&pdev->dev, NULL);
 131         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 132
 133         if (IS_ERR(dev->clk)) {
 134                 r = -ENODEV;
 135                 goto err_free_mem;
 136         }
 137         clk_prepare_enable(dev->clk);
 138
 139         dev->functionality =
 140                 I2C_FUNC_I2C |
 141                 I2C_FUNC_10BIT_ADDR |
 142                 I2C_FUNC_SMBUS_BYTE |
 143                 I2C_FUNC_SMBUS_BYTE_DATA |
 144                 I2C_FUNC_SMBUS_WORD_DATA |
 145                 I2C_FUNC_SMBUS_I2C_BLOCK;
 146         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 147                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 148
 149         dev->base = ioremap(mem->start, resource_size(mem));
 150         if (dev->base == NULL) {
 151                 dev_err(&pdev->dev, "failure mapping io resources\n");
 152                 r = -EBUSY;
 153                 goto err_unuse_clocks;
 154         }
 155
 156         /* Try first if we can configure the device from ACPI */
 157         r = dw_i2c_acpi_configure(pdev);
 158         if (r) {
 159                 u32 param1 = i2c_dw_read_comp_param(dev);
 160
 161                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 162                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 163                 dev->adapter.nr = pdev->id;
 164         }
 165         r = i2c_dw_init(dev);
 166         if (r)
 167                 goto err_iounmap;
 168
 169         i2c_dw_disable_int(dev);
 170         r = request_irq(dev->irq, i2c_dw_isr, IRQF_SHARED, pdev->name, dev);
 171         if (r) {
 172                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 173                 goto err_iounmap;
 174         }
 175
 176         adap = &dev->adapter;
 177         i2c_set_adapdata(adap, dev);
 178         adap->owner = THIS_MODULE;
 179         adap->class = I2C_CLASS_HWMON;
 180         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 181                         sizeof(adap->name));
 182         adap->algo = &i2c_dw_algo;
 183         adap->dev.parent = &pdev->dev;
 184         adap->dev.of_node = pdev->dev.of_node;
 185
 186         r = i2c_add_numbered_adapter(adap);
 187         if (r) {
 188                 dev_err(&pdev->dev, "failure adding adapter\n");
 189                 goto err_free_irq;
 190         }
 191         of_i2c_register_devices(adap);
 192         acpi_i2c_register_devices(adap);
 193
 194         pm_runtime_set_active(&pdev->dev);
 195         pm_runtime_enable(&pdev->dev);
 196         pm_runtime_put(&pdev->dev);
 197
 198         return 0;
 199
 200 err_free_irq:
 201         free_irq(dev->irq, dev);
 202 err_iounmap:
 203         iounmap(dev->base);
 204 err_unuse_clocks:
 205         clk_disable_unprepare(dev->clk);
 206         clk_put(dev->clk);
 207         dev->clk = NULL;
 208 err_free_mem:
 209         put_device(&pdev->dev);
 210         kfree(dev);
 211 err_release_region:
 212         release_mem_region(mem->start, resource_size(mem));
 213
 214         return r;
 215 }
 216
 217 static int dw_i2c_remove(struct platform_device *pdev)
 218 {
 219         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 220         struct resource *mem;
 221
 222         pm_runtime_get_sync(&pdev->dev);
 223
 224         i2c_del_adapter(&dev->adapter);
 225         put_device(&pdev->dev);
 226
 227         clk_disable_unprepare(dev->clk);
 228         clk_put(dev->clk);
 229         dev->clk = NULL;
 230
 231         i2c_dw_disable(dev);
 232         free_irq(dev->irq, dev);
 233         kfree(dev);
 234
 235         pm_runtime_put(&pdev->dev);
 236         pm_runtime_disable(&pdev->dev);
 237
 238         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 239         release_mem_region(mem->start, resource_size(mem));
 240         return 0;
 241 }
 242
 243 #ifdef CONFIG_OF
 244 static const struct of_device_id dw_i2c_of_match[] = {
 245         { .compatible = "snps,designware-i2c", },
 246         {},
 247 };
 248 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 249 #endif
 250
 251 #ifdef CONFIG_PM
 252 static int dw_i2c_suspend(struct device *dev)
 253 {
 254         struct platform_device *pdev = to_platform_device(dev);
 255         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 256
 257         clk_disable_unprepare(i_dev->clk);
 258
 259         return 0;
 260 }
 261
 262 static int dw_i2c_resume(struct device *dev)
 263 {
 264         struct platform_device *pdev = to_platform_device(dev);
 265         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 266
 267         clk_prepare_enable(i_dev->clk);
 268         i2c_dw_init(i_dev);
 269
 270         return 0;
 271 }
 272 #endif
 273
 274 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
 275
 276 /* work with hotplug and coldplug */
 277 MODULE_ALIAS("platform:i2c_designware");
 278
 279 static struct platform_driver dw_i2c_driver = {
 280         .remove         = dw_i2c_remove,
 281         .driver         = {
 282                 .name   = "i2c_designware",
 283                 .owner  = THIS_MODULE,
 284                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 285                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 286                 .pm     = &dw_i2c_dev_pm_ops,
 287         },
 288 };
 289
 290 static int __init dw_i2c_init_driver(void)
 291 {
 292         return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
 293 }
 294 subsys_initcall(dw_i2c_init_driver);
 295
 296 static void __exit dw_i2c_exit_driver(void)
 297 {
 298         platform_driver_unregister(&dw_i2c_driver);
 299 }
 300 module_exit(dw_i2c_exit_driver);
 301
 302 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 303 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 304 MODULE_LICENSE("GPL");