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/module.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/delay.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/list.h>
  30 #include <linux/delay.h>
  31 #include <linux/io.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/clk.h>
  34
  35 #include <linux/can/dev.h>
  36
  37 #include "c_can.h"
  38
  39 /*
  40  * 16-bit c_can registers can be arranged differently in the memory
  41  * architecture of different implementations. For example: 16-bit
  42  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  43  * Handle the same by providing a common read/write interface.
  44  */
  45 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
  46                                                 void *reg)
  47 {
  48         return readw(reg);
  49 }
  50
  51 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
  52                                                 void *reg, u16 val)
  53 {
  54         writew(val, reg);
  55 }
  56
  57 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
  58                                                 void *reg)
  59 {
  60         return readw(reg + (long)reg - (long)priv->regs);
  61 }
  62
  63 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
  64                                                 void *reg, u16 val)
  65 {
  66         writew(val, reg + (long)reg - (long)priv->regs);
  67 }
  68
  69 static int __devinit c_can_plat_probe(struct platform_device *pdev)
  70 {
  71         int ret;
  72         void __iomem *addr;
  73         struct net_device *dev;
  74         struct c_can_priv *priv;
  75         struct resource *mem;
  76         int irq;
  77 #ifdef CONFIG_HAVE_CLK
  78         struct clk *clk;
  79
  80         /* get the appropriate clk */
  81         clk = clk_get(&pdev->dev, NULL);
  82         if (IS_ERR(clk)) {
  83                 dev_err(&pdev->dev, "no clock defined\n");
  84                 ret = -ENODEV;
  85                 goto exit;
  86         }
  87 #endif
  88
  89         /* get the platform data */
  90         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  91         irq = platform_get_irq(pdev, 0);
  92         if (!mem || irq <= 0) {
  93                 ret = -ENODEV;
  94                 goto exit_free_clk;
  95         }
  96
  97         if (!request_mem_region(mem->start, resource_size(mem),
  98                                 KBUILD_MODNAME)) {
  99                 dev_err(&pdev->dev, "resource unavailable\n");
 100                 ret = -ENODEV;
 101                 goto exit_free_clk;
 102         }
 103
 104         addr = ioremap(mem->start, resource_size(mem));
 105         if (!addr) {
 106                 dev_err(&pdev->dev, "failed to map can port\n");
 107                 ret = -ENOMEM;
 108                 goto exit_release_mem;
 109         }
 110
 111         /* allocate the c_can device */
 112         dev = alloc_c_can_dev();
 113         if (!dev) {
 114                 ret = -ENOMEM;
 115                 goto exit_iounmap;
 116         }
 117
 118         priv = netdev_priv(dev);
 119
 120         dev->irq = irq;
 121         priv->regs = addr;
 122 #ifdef CONFIG_HAVE_CLK
 123         priv->can.clock.freq = clk_get_rate(clk);
 124         priv->priv = clk;
 125 #endif
 126
 127         switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
 128         case IORESOURCE_MEM_32BIT:
 129                 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 130                 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
 131                 break;
 132         case IORESOURCE_MEM_16BIT:
 133         default:
 134                 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 135                 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 136                 break;
 137         }
 138
 139         platform_set_drvdata(pdev, dev);
 140         SET_NETDEV_DEV(dev, &pdev->dev);
 141
 142         ret = register_c_can_dev(dev);
 143         if (ret) {
 144                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 145                         KBUILD_MODNAME, ret);
 146                 goto exit_free_device;
 147         }
 148
 149         dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
 150                  KBUILD_MODNAME, priv->regs, dev->irq);
 151         return 0;
 152
 153 exit_free_device:
 154         platform_set_drvdata(pdev, NULL);
 155         free_c_can_dev(dev);
 156 exit_iounmap:
 157         iounmap(addr);
 158 exit_release_mem:
 159         release_mem_region(mem->start, resource_size(mem));
 160 exit_free_clk:
 161 #ifdef CONFIG_HAVE_CLK
 162         clk_put(clk);
 163 exit:
 164 #endif
 165         dev_err(&pdev->dev, "probe failed\n");
 166
 167         return ret;
 168 }
 169
 170 static int __devexit c_can_plat_remove(struct platform_device *pdev)
 171 {
 172         struct net_device *dev = platform_get_drvdata(pdev);
 173         struct c_can_priv *priv = netdev_priv(dev);
 174         struct resource *mem;
 175
 176         unregister_c_can_dev(dev);
 177         platform_set_drvdata(pdev, NULL);
 178
 179         free_c_can_dev(dev);
 180         iounmap(priv->regs);
 181
 182         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 183         release_mem_region(mem->start, resource_size(mem));
 184
 185 #ifdef CONFIG_HAVE_CLK
 186         clk_put(priv->priv);
 187 #endif
 188
 189         return 0;
 190 }
 191
 192 static struct platform_driver c_can_plat_driver = {
 193         .driver = {
 194                 .name = KBUILD_MODNAME,
 195                 .owner = THIS_MODULE,
 196         },
 197         .probe = c_can_plat_probe,
 198         .remove = __devexit_p(c_can_plat_remove),
 199 };
 200
 201 static int __init c_can_plat_init(void)
 202 {
 203         return platform_driver_register(&c_can_plat_driver);
 204 }
 205 module_init(c_can_plat_init);
 206
 207 static void __exit c_can_plat_exit(void)
 208 {
 209         platform_driver_unregister(&c_can_plat_driver);
 210 }
 211 module_exit(c_can_plat_exit);
 212
 213 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
 214 MODULE_LICENSE("GPL v2");
 215 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");