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                                                 enum reg index)
  46 {
  47         return readw(priv->base + priv->regs[index]);
  48 }
  49
  50 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
  51                                                 enum reg index, u16 val)
  52 {
  53         writew(val, priv->base + priv->regs[index]);
  54 }
  55
  56 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
  57                                                 enum reg index)
  58 {
  59         return readw(priv->base + 2 * priv->regs[index]);
  60 }
  61
  62 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
  63                                                 enum reg index, u16 val)
  64 {
  65         writew(val, priv->base + 2 * priv->regs[index]);
  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         const struct platform_device_id *id;
  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         id = platform_get_device_id(pdev);
 120         switch (id->driver_data) {
 121         case C_CAN_DEVTYPE:
 122                 priv->regs = reg_map_c_can;
 123                 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
 124                 case IORESOURCE_MEM_32BIT:
 125                         priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 126                         priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
 127                         break;
 128                 case IORESOURCE_MEM_16BIT:
 129                 default:
 130                         priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 131                         priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 132                         break;
 133                 }
 134                 break;
 135         case D_CAN_DEVTYPE:
 136                 priv->regs = reg_map_d_can;
 137                 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 138                 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 139                 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 140                 break;
 141         default:
 142                 ret = -EINVAL;
 143                 goto exit_free_device;
 144         }
 145
 146         dev->irq = irq;
 147         priv->base = addr;
 148 #ifdef CONFIG_HAVE_CLK
 149         priv->can.clock.freq = clk_get_rate(clk);
 150         priv->priv = clk;
 151 #endif
 152
 153         platform_set_drvdata(pdev, dev);
 154         SET_NETDEV_DEV(dev, &pdev->dev);
 155
 156         ret = register_c_can_dev(dev);
 157         if (ret) {
 158                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 159                         KBUILD_MODNAME, ret);
 160                 goto exit_free_device;
 161         }
 162
 163         dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
 164                  KBUILD_MODNAME, priv->base, dev->irq);
 165         return 0;
 166
 167 exit_free_device:
 168         platform_set_drvdata(pdev, NULL);
 169         free_c_can_dev(dev);
 170 exit_iounmap:
 171         iounmap(addr);
 172 exit_release_mem:
 173         release_mem_region(mem->start, resource_size(mem));
 174 exit_free_clk:
 175 #ifdef CONFIG_HAVE_CLK
 176         clk_put(clk);
 177 exit:
 178 #endif
 179         dev_err(&pdev->dev, "probe failed\n");
 180
 181         return ret;
 182 }
 183
 184 static int __devexit c_can_plat_remove(struct platform_device *pdev)
 185 {
 186         struct net_device *dev = platform_get_drvdata(pdev);
 187         struct c_can_priv *priv = netdev_priv(dev);
 188         struct resource *mem;
 189
 190         unregister_c_can_dev(dev);
 191         platform_set_drvdata(pdev, NULL);
 192
 193         free_c_can_dev(dev);
 194         iounmap(priv->base);
 195
 196         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 197         release_mem_region(mem->start, resource_size(mem));
 198
 199 #ifdef CONFIG_HAVE_CLK
 200         clk_put(priv->priv);
 201 #endif
 202
 203         return 0;
 204 }
 205
 206 static const struct platform_device_id c_can_id_table[] = {
 207         {
 208                 .name = KBUILD_MODNAME,
 209                 .driver_data = C_CAN_DEVTYPE,
 210         }, {
 211                 .name = "c_can",
 212                 .driver_data = C_CAN_DEVTYPE,
 213         }, {
 214                 .name = "d_can",
 215                 .driver_data = D_CAN_DEVTYPE,
 216         }, {
 217         }
 218 };
 219
 220 static struct platform_driver c_can_plat_driver = {
 221         .driver = {
 222                 .name = KBUILD_MODNAME,
 223                 .owner = THIS_MODULE,
 224         },
 225         .probe = c_can_plat_probe,
 226         .remove = __devexit_p(c_can_plat_remove),
 227         .id_table = c_can_id_table,
 228 };
 229
 230 module_platform_driver(c_can_plat_driver);
 231
 232 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
 233 MODULE_LICENSE("GPL v2");
 234 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");