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/platform_device.h>
  38 #include <linux/io.h>
  39 #include <linux/slab.h>
  40 #include "i2c-designware-core.h"
  41
  42 static struct i2c_algorithm i2c_dw_algo = {
  43         .master_xfer    = i2c_dw_xfer,
  44         .functionality  = i2c_dw_func,
  45 };
  46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  47 {
  48         return clk_get_rate(dev->clk)/1000;
  49 }
  50
  51 static int __devinit dw_i2c_probe(struct platform_device *pdev)
  52 {
  53         struct dw_i2c_dev *dev;
  54         struct i2c_adapter *adap;
  55         struct resource *mem, *ioarea;
  56         int irq, r;
  57
  58         /* NOTE: driver uses the static register mapping */
  59         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  60         if (!mem) {
  61                 dev_err(&pdev->dev, "no mem resource?\n");
  62                 return -EINVAL;
  63         }
  64
  65         irq = platform_get_irq(pdev, 0);
  66         if (irq < 0) {
  67                 dev_err(&pdev->dev, "no irq resource?\n");
  68                 return irq; /* -ENXIO */
  69         }
  70
  71         ioarea = request_mem_region(mem->start, resource_size(mem),
  72                         pdev->name);
  73         if (!ioarea) {
  74                 dev_err(&pdev->dev, "I2C region already claimed\n");
  75                 return -EBUSY;
  76         }
  77
  78         dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
  79         if (!dev) {
  80                 r = -ENOMEM;
  81                 goto err_release_region;
  82         }
  83
  84         init_completion(&dev->cmd_complete);
  85         mutex_init(&dev->lock);
  86         dev->dev = get_device(&pdev->dev);
  87         dev->irq = irq;
  88         platform_set_drvdata(pdev, dev);
  89
  90         dev->clk = clk_get(&pdev->dev, NULL);
  91         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
  92
  93         if (IS_ERR(dev->clk)) {
  94                 r = -ENODEV;
  95                 goto err_free_mem;
  96         }
  97         clk_enable(dev->clk);
  98
  99         dev->functionality =
 100                 I2C_FUNC_I2C |
 101                 I2C_FUNC_10BIT_ADDR |
 102                 I2C_FUNC_SMBUS_BYTE |
 103                 I2C_FUNC_SMBUS_BYTE_DATA |
 104                 I2C_FUNC_SMBUS_WORD_DATA |
 105                 I2C_FUNC_SMBUS_I2C_BLOCK;
 106
 107         dev->base = ioremap(mem->start, resource_size(mem));
 108         if (dev->base == NULL) {
 109                 dev_err(&pdev->dev, "failure mapping io resources\n");
 110                 r = -EBUSY;
 111                 goto err_unuse_clocks;
 112         }
 113         {
 114                 u32 param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
 115
 116                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 117                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 118         }
 119         r = i2c_dw_init(dev);
 120         if (r)
 121                 goto err_iounmap;
 122
 123         dw_writel(dev, 0, DW_IC_INTR_MASK); /* disable IRQ */
 124         r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
 125         if (r) {
 126                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 127                 goto err_iounmap;
 128         }
 129
 130         adap = &dev->adapter;
 131         i2c_set_adapdata(adap, dev);
 132         adap->owner = THIS_MODULE;
 133         adap->class = I2C_CLASS_HWMON;
 134         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 135                         sizeof(adap->name));
 136         adap->algo = &i2c_dw_algo;
 137         adap->dev.parent = &pdev->dev;
 138
 139         adap->nr = pdev->id;
 140         r = i2c_add_numbered_adapter(adap);
 141         if (r) {
 142                 dev_err(&pdev->dev, "failure adding adapter\n");
 143                 goto err_free_irq;
 144         }
 145
 146         return 0;
 147
 148 err_free_irq:
 149         free_irq(dev->irq, dev);
 150 err_iounmap:
 151         iounmap(dev->base);
 152 err_unuse_clocks:
 153         clk_disable(dev->clk);
 154         clk_put(dev->clk);
 155         dev->clk = NULL;
 156 err_free_mem:
 157         platform_set_drvdata(pdev, NULL);
 158         put_device(&pdev->dev);
 159         kfree(dev);
 160 err_release_region:
 161         release_mem_region(mem->start, resource_size(mem));
 162
 163         return r;
 164 }
 165
 166 static int __devexit dw_i2c_remove(struct platform_device *pdev)
 167 {
 168         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 169         struct resource *mem;
 170
 171         platform_set_drvdata(pdev, NULL);
 172         i2c_del_adapter(&dev->adapter);
 173         put_device(&pdev->dev);
 174
 175         clk_disable(dev->clk);
 176         clk_put(dev->clk);
 177         dev->clk = NULL;
 178
 179         dw_writel(dev, 0, DW_IC_ENABLE);
 180         free_irq(dev->irq, dev);
 181         kfree(dev);
 182
 183         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 184         release_mem_region(mem->start, resource_size(mem));
 185         return 0;
 186 }
 187
 188 /* work with hotplug and coldplug */
 189 MODULE_ALIAS("platform:i2c_designware");
 190
 191 static struct platform_driver dw_i2c_driver = {
 192         .remove         = __devexit_p(dw_i2c_remove),
 193         .driver         = {
 194                 .name   = "i2c_designware",
 195                 .owner  = THIS_MODULE,
 196         },
 197 };
 198
 199 static int __init dw_i2c_init_driver(void)
 200 {
 201         return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
 202 }
 203 module_init(dw_i2c_init_driver);
 204
 205 static void __exit dw_i2c_exit_driver(void)
 206 {
 207         platform_driver_unregister(&dw_i2c_driver);
 208 }
 209 module_exit(dw_i2c_exit_driver);
 210
 211 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 212 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 213 MODULE_LICENSE("GPL");