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/io.h>
  41 #include <linux/slab.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 static int __devinit dw_i2c_probe(struct platform_device *pdev)
  54 {
  55         struct dw_i2c_dev *dev;
  56         struct i2c_adapter *adap;
  57         struct resource *mem, *ioarea;
  58         int irq, r;
  59
  60         /* NOTE: driver uses the static register mapping */
  61         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  62         if (!mem) {
  63                 dev_err(&pdev->dev, "no mem resource?\n");
  64                 return -EINVAL;
  65         }
  66
  67         irq = platform_get_irq(pdev, 0);
  68         if (irq < 0) {
  69                 dev_err(&pdev->dev, "no irq resource?\n");
  70                 return irq; /* -ENXIO */
  71         }
  72
  73         ioarea = request_mem_region(mem->start, resource_size(mem),
  74                         pdev->name);
  75         if (!ioarea) {
  76                 dev_err(&pdev->dev, "I2C region already claimed\n");
  77                 return -EBUSY;
  78         }
  79
  80         dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
  81         if (!dev) {
  82                 r = -ENOMEM;
  83                 goto err_release_region;
  84         }
  85
  86         init_completion(&dev->cmd_complete);
  87         mutex_init(&dev->lock);
  88         dev->dev = get_device(&pdev->dev);
  89         dev->irq = irq;
  90         platform_set_drvdata(pdev, dev);
  91
  92         dev->clk = clk_get(&pdev->dev, NULL);
  93         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
  94
  95         if (IS_ERR(dev->clk)) {
  96                 r = -ENODEV;
  97                 goto err_free_mem;
  98         }
  99         clk_prepare_enable(dev->clk);
 100
 101         dev->functionality =
 102                 I2C_FUNC_I2C |
 103                 I2C_FUNC_10BIT_ADDR |
 104                 I2C_FUNC_SMBUS_BYTE |
 105                 I2C_FUNC_SMBUS_BYTE_DATA |
 106                 I2C_FUNC_SMBUS_WORD_DATA |
 107                 I2C_FUNC_SMBUS_I2C_BLOCK;
 108         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 109                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 110
 111         dev->base = ioremap(mem->start, resource_size(mem));
 112         if (dev->base == NULL) {
 113                 dev_err(&pdev->dev, "failure mapping io resources\n");
 114                 r = -EBUSY;
 115                 goto err_unuse_clocks;
 116         }
 117         {
 118                 u32 param1 = i2c_dw_read_comp_param(dev);
 119
 120                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 121                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 122         }
 123         r = i2c_dw_init(dev);
 124         if (r)
 125                 goto err_iounmap;
 126
 127         i2c_dw_disable_int(dev);
 128         r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
 129         if (r) {
 130                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 131                 goto err_iounmap;
 132         }
 133
 134         adap = &dev->adapter;
 135         i2c_set_adapdata(adap, dev);
 136         adap->owner = THIS_MODULE;
 137         adap->class = I2C_CLASS_HWMON;
 138         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 139                         sizeof(adap->name));
 140         adap->algo = &i2c_dw_algo;
 141         adap->dev.parent = &pdev->dev;
 142         adap->dev.of_node = pdev->dev.of_node;
 143
 144         adap->nr = pdev->id;
 145         r = i2c_add_numbered_adapter(adap);
 146         if (r) {
 147                 dev_err(&pdev->dev, "failure adding adapter\n");
 148                 goto err_free_irq;
 149         }
 150         of_i2c_register_devices(adap);
 151
 152         return 0;
 153
 154 err_free_irq:
 155         free_irq(dev->irq, dev);
 156 err_iounmap:
 157         iounmap(dev->base);
 158 err_unuse_clocks:
 159         clk_disable_unprepare(dev->clk);
 160         clk_put(dev->clk);
 161         dev->clk = NULL;
 162 err_free_mem:
 163         platform_set_drvdata(pdev, NULL);
 164         put_device(&pdev->dev);
 165         kfree(dev);
 166 err_release_region:
 167         release_mem_region(mem->start, resource_size(mem));
 168
 169         return r;
 170 }
 171
 172 static int __devexit dw_i2c_remove(struct platform_device *pdev)
 173 {
 174         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 175         struct resource *mem;
 176
 177         platform_set_drvdata(pdev, NULL);
 178         i2c_del_adapter(&dev->adapter);
 179         put_device(&pdev->dev);
 180
 181         clk_disable_unprepare(dev->clk);
 182         clk_put(dev->clk);
 183         dev->clk = NULL;
 184
 185         i2c_dw_disable(dev);
 186         free_irq(dev->irq, dev);
 187         kfree(dev);
 188
 189         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 190         release_mem_region(mem->start, resource_size(mem));
 191         return 0;
 192 }
 193
 194 #ifdef CONFIG_OF
 195 static const struct of_device_id dw_i2c_of_match[] = {
 196         { .compatible = "snps,designware-i2c", },
 197         {},
 198 };
 199 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 200 #endif
 201
 202 #ifdef CONFIG_PM
 203 static int dw_i2c_suspend(struct device *dev)
 204 {
 205         struct platform_device *pdev = to_platform_device(dev);
 206         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 207
 208         clk_disable_unprepare(i_dev->clk);
 209
 210         return 0;
 211 }
 212
 213 static int dw_i2c_resume(struct device *dev)
 214 {
 215         struct platform_device *pdev = to_platform_device(dev);
 216         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 217
 218         clk_prepare_enable(i_dev->clk);
 219         i2c_dw_init(i_dev);
 220
 221         return 0;
 222 }
 223 #endif
 224
 225 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
 226
 227 /* work with hotplug and coldplug */
 228 MODULE_ALIAS("platform:i2c_designware");
 229
 230 static struct platform_driver dw_i2c_driver = {
 231         .remove         = __devexit_p(dw_i2c_remove),
 232         .driver         = {
 233                 .name   = "i2c_designware",
 234                 .owner  = THIS_MODULE,
 235                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 236                 .pm     = &dw_i2c_dev_pm_ops,
 237         },
 238 };
 239
 240 static int __init dw_i2c_init_driver(void)
 241 {
 242         return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
 243 }
 244 subsys_initcall(dw_i2c_init_driver);
 245
 246 static void __exit dw_i2c_exit_driver(void)
 247 {
 248         platform_driver_unregister(&dw_i2c_driver);
 249 }
 250 module_exit(dw_i2c_exit_driver);
 251
 252 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 253 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 254 MODULE_LICENSE("GPL");