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