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 #include <linux/of.h>
  34 #include <linux/of_device.h>
  35
  36 #include <linux/can/dev.h>
  37
  38 #include "c_can.h"
  39
  40 #define CAN_RAMINIT_START_MASK(i)       (1 << (i))
  41
  42 /*
  43  * 16-bit c_can registers can be arranged differently in the memory
  44  * architecture of different implementations. For example: 16-bit
  45  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  46  * Handle the same by providing a common read/write interface.
  47  */
  48 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
  49                                                 enum reg index)
  50 {
  51         return readw(priv->base + priv->regs[index]);
  52 }
  53
  54 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
  55                                                 enum reg index, u16 val)
  56 {
  57         writew(val, priv->base + priv->regs[index]);
  58 }
  59
  60 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
  61                                                 enum reg index)
  62 {
  63         return readw(priv->base + 2 * priv->regs[index]);
  64 }
  65
  66 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
  67                                                 enum reg index, u16 val)
  68 {
  69         writew(val, priv->base + 2 * priv->regs[index]);
  70 }
  71
  72 static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
  73 {
  74         u32 val;
  75
  76         val = readl(priv->raminit_ctrlreg);
  77         if (enable)
  78                 val |= CAN_RAMINIT_START_MASK(priv->instance);
  79         else
  80                 val &= ~CAN_RAMINIT_START_MASK(priv->instance);
  81         writel(val, priv->raminit_ctrlreg);
  82 }
  83
  84 static struct platform_device_id c_can_id_table[] = {
  85         [BOSCH_C_CAN_PLATFORM] = {
  86                 .name = KBUILD_MODNAME,
  87                 .driver_data = BOSCH_C_CAN,
  88         },
  89         [BOSCH_C_CAN] = {
  90                 .name = "c_can",
  91                 .driver_data = BOSCH_C_CAN,
  92         },
  93         [BOSCH_D_CAN] = {
  94                 .name = "d_can",
  95                 .driver_data = BOSCH_D_CAN,
  96         }, {
  97         }
  98 };
  99 MODULE_DEVICE_TABLE(platform, c_can_id_table);
 100
 101 static const struct of_device_id c_can_of_table[] = {
 102         { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
 103         { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
 104         { /* sentinel */ },
 105 };
 106 MODULE_DEVICE_TABLE(of, c_can_of_table);
 107
 108 static int c_can_plat_probe(struct platform_device *pdev)
 109 {
 110         int ret;
 111         void __iomem *addr;
 112         struct net_device *dev;
 113         struct c_can_priv *priv;
 114         const struct of_device_id *match;
 115         const struct platform_device_id *id;
 116         struct resource *mem, *res;
 117         int irq;
 118         struct clk *clk;
 119
 120         if (pdev->dev.of_node) {
 121                 match = of_match_device(c_can_of_table, &pdev->dev);
 122                 if (!match) {
 123                         dev_err(&pdev->dev, "Failed to find matching dt id\n");
 124                         ret = -EINVAL;
 125                         goto exit;
 126                 }
 127                 id = match->data;
 128         } else {
 129                 id = platform_get_device_id(pdev);
 130         }
 131
 132         /* get the appropriate clk */
 133         clk = clk_get(&pdev->dev, NULL);
 134         if (IS_ERR(clk)) {
 135                 dev_err(&pdev->dev, "no clock defined\n");
 136                 ret = -ENODEV;
 137                 goto exit;
 138         }
 139
 140         /* get the platform data */
 141         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 142         irq = platform_get_irq(pdev, 0);
 143         if (!mem || irq <= 0) {
 144                 ret = -ENODEV;
 145                 goto exit_free_clk;
 146         }
 147
 148         if (!request_mem_region(mem->start, resource_size(mem),
 149                                 KBUILD_MODNAME)) {
 150                 dev_err(&pdev->dev, "resource unavailable\n");
 151                 ret = -ENODEV;
 152                 goto exit_free_clk;
 153         }
 154
 155         addr = ioremap(mem->start, resource_size(mem));
 156         if (!addr) {
 157                 dev_err(&pdev->dev, "failed to map can port\n");
 158                 ret = -ENOMEM;
 159                 goto exit_release_mem;
 160         }
 161
 162         /* allocate the c_can device */
 163         dev = alloc_c_can_dev();
 164         if (!dev) {
 165                 ret = -ENOMEM;
 166                 goto exit_iounmap;
 167         }
 168
 169         priv = netdev_priv(dev);
 170         switch (id->driver_data) {
 171         case BOSCH_C_CAN:
 172                 priv->regs = reg_map_c_can;
 173                 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
 174                 case IORESOURCE_MEM_32BIT:
 175                         priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 176                         priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
 177                         break;
 178                 case IORESOURCE_MEM_16BIT:
 179                 default:
 180                         priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 181                         priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 182                         break;
 183                 }
 184                 break;
 185         case BOSCH_D_CAN:
 186                 priv->regs = reg_map_d_can;
 187                 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 188                 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 189                 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
 190
 191                 if (pdev->dev.of_node)
 192                         priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
 193                 else
 194                         priv->instance = pdev->id;
 195
 196                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 197                 priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
 198                 if (IS_ERR(priv->raminit_ctrlreg) || (int)priv->instance < 0)
 199                         dev_info(&pdev->dev, "control memory is not used for raminit\n");
 200                 else
 201                         priv->raminit = c_can_hw_raminit;
 202                 break;
 203         default:
 204                 ret = -EINVAL;
 205                 goto exit_free_device;
 206         }
 207
 208         dev->irq = irq;
 209         priv->base = addr;
 210         priv->device = &pdev->dev;
 211         priv->can.clock.freq = clk_get_rate(clk);
 212         priv->priv = clk;
 213         priv->type = id->driver_data;
 214
 215         platform_set_drvdata(pdev, dev);
 216         SET_NETDEV_DEV(dev, &pdev->dev);
 217
 218         ret = register_c_can_dev(dev);
 219         if (ret) {
 220                 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 221                         KBUILD_MODNAME, ret);
 222                 goto exit_free_device;
 223         }
 224
 225         dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
 226                  KBUILD_MODNAME, priv->base, dev->irq);
 227         return 0;
 228
 229 exit_free_device:
 230         free_c_can_dev(dev);
 231 exit_iounmap:
 232         iounmap(addr);
 233 exit_release_mem:
 234         release_mem_region(mem->start, resource_size(mem));
 235 exit_free_clk:
 236         clk_put(clk);
 237 exit:
 238         dev_err(&pdev->dev, "probe failed\n");
 239
 240         return ret;
 241 }
 242
 243 static int c_can_plat_remove(struct platform_device *pdev)
 244 {
 245         struct net_device *dev = platform_get_drvdata(pdev);
 246         struct c_can_priv *priv = netdev_priv(dev);
 247         struct resource *mem;
 248
 249         unregister_c_can_dev(dev);
 250
 251         free_c_can_dev(dev);
 252         iounmap(priv->base);
 253
 254         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 255         release_mem_region(mem->start, resource_size(mem));
 256
 257         clk_put(priv->priv);
 258
 259         return 0;
 260 }
 261
 262 #ifdef CONFIG_PM
 263 static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
 264 {
 265         int ret;
 266         struct net_device *ndev = platform_get_drvdata(pdev);
 267         struct c_can_priv *priv = netdev_priv(ndev);
 268
 269         if (priv->type != BOSCH_D_CAN) {
 270                 dev_warn(&pdev->dev, "Not supported\n");
 271                 return 0;
 272         }
 273
 274         if (netif_running(ndev)) {
 275                 netif_stop_queue(ndev);
 276                 netif_device_detach(ndev);
 277         }
 278
 279         ret = c_can_power_down(ndev);
 280         if (ret) {
 281                 netdev_err(ndev, "failed to enter power down mode\n");
 282                 return ret;
 283         }
 284
 285         priv->can.state = CAN_STATE_SLEEPING;
 286
 287         return 0;
 288 }
 289
 290 static int c_can_resume(struct platform_device *pdev)
 291 {
 292         int ret;
 293         struct net_device *ndev = platform_get_drvdata(pdev);
 294         struct c_can_priv *priv = netdev_priv(ndev);
 295
 296         if (priv->type != BOSCH_D_CAN) {
 297                 dev_warn(&pdev->dev, "Not supported\n");
 298                 return 0;
 299         }
 300
 301         ret = c_can_power_up(ndev);
 302         if (ret) {
 303                 netdev_err(ndev, "Still in power down mode\n");
 304                 return ret;
 305         }
 306
 307         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 308
 309         if (netif_running(ndev)) {
 310                 netif_device_attach(ndev);
 311                 netif_start_queue(ndev);
 312         }
 313
 314         return 0;
 315 }
 316 #else
 317 #define c_can_suspend NULL
 318 #define c_can_resume NULL
 319 #endif
 320
 321 static struct platform_driver c_can_plat_driver = {
 322         .driver = {
 323                 .name = KBUILD_MODNAME,
 324                 .owner = THIS_MODULE,
 325                 .of_match_table = c_can_of_table,
 326         },
 327         .probe = c_can_plat_probe,
 328         .remove = c_can_plat_remove,
 329         .suspend = c_can_suspend,
 330         .resume = c_can_resume,
 331         .id_table = c_can_id_table,
 332 };
 333
 334 module_platform_driver(c_can_plat_driver);
 335
 336 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
 337 MODULE_LICENSE("GPL v2");
 338 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");