drivers/net/can/c_can/c_can_platform.c

   1 /*
   2  * Platform CAN bus driver for Bosch C_CAN controller
   3  *
   4  * Copyright (C) 2010 ST Microelectronics
   5  * Bhupesh Sharma <bhupesh.sharma@st.com>
   6  *
   7  * Borrowed heavily from the C_CAN driver originally written by:
   8  * Copyright (C) 2007
   9  * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
  10  * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
  11  *
  12  * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B.
  13  * Bosch C_CAN user manual can be obtained from:
  14  * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
  15  * users_manual_c_can.pdf
  16  *
  17  * This file is licensed under the terms of the GNU General Public
  18  * License version 2. This program is licensed "as is" without any
  19  * warranty of any kind, whether express or implied.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/version.h>
  24 #include <linux/module.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/delay.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/list.h>
  31 #include <linux/delay.h>
  32 #include <linux/io.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/clk.h>
  35
  36 #include <linux/can/dev.h>
  37
  38 #include "c_can.h"
  39
  40 /*
  41  * 16-bit c_can registers can be arranged differently in the memory
  42  * architecture of different implementations. For example: 16-bit
  43  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  44  * Handle the same by providing a common read/write interface.
  45  */
  46 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
  47                                                 void *reg)
  48 {
  49         return readw(reg);
  50 }
  51
  52 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
  53                                                 void *reg, u16 val)
  54 {
  55         writew(val, reg);
  56 }
  57
  58 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
  59                                                 void *reg)
  60 {
  61         return readw(reg + (long)reg - (long)priv->regs);
  62 }
  63
  64 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
  65                                                 void *reg, u16 val)
  66 {
  67         writew(val, reg + (long)reg - (long)priv->regs);
  68 }
  69
  70 static int __devinit c_can_plat_probe(struct platform_device *pdev)
  71 {
  72         int ret;
  73         void __iomem *addr;
  74         struct net_device *dev;
  75         struct c_can_priv *priv;
  76         struct resource *mem;
  77         int irq;
  78 #ifdef CONFIG_HAVE_CLK
  79         struct clk *clk;
  80
  81         /* get the appropriate clk */
  82         clk = clk_get(&pdev->dev, NULL);
  83         if (IS_ERR(clk)) {
  84                 dev_err(&pdev->dev, "no clock defined\n");
  85                 ret = -ENODEV;
  86                 goto exit;
  87         }
  88 #endif
  89
  90         /* get the platform data */
  91         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  92         irq = platform_get_irq(pdev, 0);
  93         if (!mem || irq <= 0) {
  94                 ret = -ENODEV;
  95                 goto exit_free_clk;
  96         }
  97
  98         if (!request_mem_region(mem->start, resource_size(mem),
  99                                 KBUILD_MODNAME)) {
 100                 dev_err(&pdev->dev, "resource unavailable\n");
 101                 ret = -ENODEV;
 102                 goto exit_free_clk;
 103         }
 104
 105         addr = ioremap(mem->start, resource_size(mem));
 106         if (!addr) {
 107                 dev_err(&pdev->dev, "failed to map can port\n");
 108                 ret = -ENOMEM;
 109                 goto exit_release_mem;
 110         }
 111
 112         /* allocate the c_can device */
 113         dev = alloc_c_can_dev();
 114         if (!dev) {
 115                 ret = -ENOMEM;
 116                 goto exit_iounmap;
 117         }
 118
 119         priv = netdev_priv(dev);
 120
 121         dev->irq = irq;
 122         priv->regs = addr;
 123 #ifdef CONFIG_HAVE_CLK
 124         priv->can.clock.freq = clk_get_rate(clk);
 125         priv->priv = clk;
 126 #endif
 127
 128         switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
 129         case IORESOURCE_MEM_32BIT:
 130                 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 131                 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
 132                 break;
 133         case IORESOURCE_MEM_16BIT:
 134         default:
 135                 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 136                 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 137                 break;
 138         }
 139
 140         platform_set_drvdata(pdev, dev);
 141         SET_NETDEV_DEV(dev, &pdev->dev);
 142
 143         ret = register_c_can_dev(dev);
 144         if (ret) {
 145                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 146                         KBUILD_MODNAME, ret);
 147                 goto exit_free_device;
 148         }
 149
 150         dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
 151                  KBUILD_MODNAME, priv->regs, dev->irq);
 152         return 0;
 153
 154 exit_free_device:
 155         platform_set_drvdata(pdev, NULL);
 156         free_c_can_dev(dev);
 157 exit_iounmap:
 158         iounmap(addr);
 159 exit_release_mem:
 160         release_mem_region(mem->start, resource_size(mem));
 161 exit_free_clk:
 162 #ifdef CONFIG_HAVE_CLK
 163         clk_put(clk);
 164 exit:
 165 #endif
 166         dev_err(&pdev->dev, "probe failed\n");
 167
 168         return ret;
 169 }
 170
 171 static int __devexit c_can_plat_remove(struct platform_device *pdev)
 172 {
 173         struct net_device *dev = platform_get_drvdata(pdev);
 174         struct c_can_priv *priv = netdev_priv(dev);
 175         struct resource *mem;
 176
 177         unregister_c_can_dev(dev);
 178         platform_set_drvdata(pdev, NULL);
 179
 180         free_c_can_dev(dev);
 181         iounmap(priv->regs);
 182
 183         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 184         release_mem_region(mem->start, resource_size(mem));
 185
 186 #ifdef CONFIG_HAVE_CLK
 187         clk_put(priv->priv);
 188 #endif
 189
 190         return 0;
 191 }
 192
 193 static struct platform_driver c_can_plat_driver = {
 194         .driver = {
 195                 .name = KBUILD_MODNAME,
 196                 .owner = THIS_MODULE,
 197         },
 198         .probe = c_can_plat_probe,
 199         .remove = __devexit_p(c_can_plat_remove),
 200 };
 201
 202 static int __init c_can_plat_init(void)
 203 {
 204         return platform_driver_register(&c_can_plat_driver);
 205 }
 206 module_init(c_can_plat_init);
 207
 208 static void __exit c_can_plat_exit(void)
 209 {
 210         platform_driver_unregister(&c_can_plat_driver);
 211 }
 212 module_exit(c_can_plat_exit);
 213
 214 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
 215 MODULE_LICENSE("GPL v2");
 216 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");