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/io.h>
  40 #include <linux/slab.h>
  41 #include "i2c-designware-core.h"
  42
  43 static struct i2c_algorithm i2c_dw_algo = {
  44         .master_xfer    = i2c_dw_xfer,
  45         .functionality  = i2c_dw_func,
  46 };
  47 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  48 {
  49         return clk_get_rate(dev->clk)/1000;
  50 }
  51
  52 static int __devinit dw_i2c_probe(struct platform_device *pdev)
  53 {
  54         struct dw_i2c_dev *dev;
  55         struct i2c_adapter *adap;
  56         struct resource *mem, *ioarea;
  57         int irq, r;
  58
  59         /* NOTE: driver uses the static register mapping */
  60         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  61         if (!mem) {
  62                 dev_err(&pdev->dev, "no mem resource?\n");
  63                 return -EINVAL;
  64         }
  65
  66         irq = platform_get_irq(pdev, 0);
  67         if (irq < 0) {
  68                 dev_err(&pdev->dev, "no irq resource?\n");
  69                 return irq; /* -ENXIO */
  70         }
  71
  72         ioarea = request_mem_region(mem->start, resource_size(mem),
  73                         pdev->name);
  74         if (!ioarea) {
  75                 dev_err(&pdev->dev, "I2C region already claimed\n");
  76                 return -EBUSY;
  77         }
  78
  79         dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
  80         if (!dev) {
  81                 r = -ENOMEM;
  82                 goto err_release_region;
  83         }
  84
  85         init_completion(&dev->cmd_complete);
  86         mutex_init(&dev->lock);
  87         dev->dev = get_device(&pdev->dev);
  88         dev->irq = irq;
  89         platform_set_drvdata(pdev, dev);
  90
  91         dev->clk = clk_get(&pdev->dev, NULL);
  92         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
  93
  94         if (IS_ERR(dev->clk)) {
  95                 r = -ENODEV;
  96                 goto err_free_mem;
  97         }
  98         clk_enable(dev->clk);
  99
 100         dev->functionality =
 101                 I2C_FUNC_I2C |
 102                 I2C_FUNC_10BIT_ADDR |
 103                 I2C_FUNC_SMBUS_BYTE |
 104                 I2C_FUNC_SMBUS_BYTE_DATA |
 105                 I2C_FUNC_SMBUS_WORD_DATA |
 106                 I2C_FUNC_SMBUS_I2C_BLOCK;
 107         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 108                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 109
 110         dev->base = ioremap(mem->start, resource_size(mem));
 111         if (dev->base == NULL) {
 112                 dev_err(&pdev->dev, "failure mapping io resources\n");
 113                 r = -EBUSY;
 114                 goto err_unuse_clocks;
 115         }
 116         {
 117                 u32 param1 = i2c_dw_read_comp_param(dev);
 118
 119                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 120                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 121         }
 122         r = i2c_dw_init(dev);
 123         if (r)
 124                 goto err_iounmap;
 125
 126         i2c_dw_disable_int(dev);
 127         r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
 128         if (r) {
 129                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 130                 goto err_iounmap;
 131         }
 132
 133         adap = &dev->adapter;
 134         i2c_set_adapdata(adap, dev);
 135         adap->owner = THIS_MODULE;
 136         adap->class = I2C_CLASS_HWMON;
 137         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 138                         sizeof(adap->name));
 139         adap->algo = &i2c_dw_algo;
 140         adap->dev.parent = &pdev->dev;
 141         adap->dev.of_node = pdev->dev.of_node;
 142
 143         adap->nr = pdev->id;
 144         r = i2c_add_numbered_adapter(adap);
 145         if (r) {
 146                 dev_err(&pdev->dev, "failure adding adapter\n");
 147                 goto err_free_irq;
 148         }
 149         of_i2c_register_devices(adap);
 150
 151         return 0;
 152
 153 err_free_irq:
 154         free_irq(dev->irq, dev);
 155 err_iounmap:
 156         iounmap(dev->base);
 157 err_unuse_clocks:
 158         clk_disable(dev->clk);
 159         clk_put(dev->clk);
 160         dev->clk = NULL;
 161 err_free_mem:
 162         platform_set_drvdata(pdev, NULL);
 163         put_device(&pdev->dev);
 164         kfree(dev);
 165 err_release_region:
 166         release_mem_region(mem->start, resource_size(mem));
 167
 168         return r;
 169 }
 170
 171 static int __devexit dw_i2c_remove(struct platform_device *pdev)
 172 {
 173         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 174         struct resource *mem;
 175
 176         platform_set_drvdata(pdev, NULL);
 177         i2c_del_adapter(&dev->adapter);
 178         put_device(&pdev->dev);
 179
 180         clk_disable(dev->clk);
 181         clk_put(dev->clk);
 182         dev->clk = NULL;
 183
 184         i2c_dw_disable(dev);
 185         free_irq(dev->irq, dev);
 186         kfree(dev);
 187
 188         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 189         release_mem_region(mem->start, resource_size(mem));
 190         return 0;
 191 }
 192
 193 #ifdef CONFIG_OF
 194 static const struct of_device_id dw_i2c_of_match[] = {
 195         { .compatible = "snps,designware-i2c", },
 196         {},
 197 };
 198 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 199 #endif
 200
 201 /* work with hotplug and coldplug */
 202 MODULE_ALIAS("platform:i2c_designware");
 203
 204 static struct platform_driver dw_i2c_driver = {
 205         .remove         = __devexit_p(dw_i2c_remove),
 206         .driver         = {
 207                 .name   = "i2c_designware",
 208                 .owner  = THIS_MODULE,
 209                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 210         },
 211 };
 212
 213 static int __init dw_i2c_init_driver(void)
 214 {
 215         return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
 216 }
 217 subsys_initcall(dw_i2c_init_driver);
 218
 219 static void __exit dw_i2c_exit_driver(void)
 220 {
 221         platform_driver_unregister(&dw_i2c_driver);
 222 }
 223 module_exit(dw_i2c_exit_driver);
 224
 225 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 226 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 227 MODULE_LICENSE("GPL");