drivers/net/can/cc770/cc770_isa.c

   1 /*
   2  * Driver for CC770 and AN82527 CAN controllers on the legacy ISA bus
   3  *
   4  * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 /*
  17  * Bosch CC770 and Intel AN82527 CAN controllers on the ISA or PC-104 bus.
  18  * The I/O port or memory address and the IRQ number must be specified via
  19  * module parameters:
  20  *
  21  *   insmod cc770_isa.ko port=0x310,0x380 irq=7,11
  22  *
  23  * for ISA devices using I/O ports or:
  24  *
  25  *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11
  26  *
  27  * for memory mapped ISA devices.
  28  *
  29  * Indirect access via address and data port is supported as well:
  30  *
  31  *   insmod cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11
  32  *
  33  * Furthermore, the following mode parameter can be defined:
  34  *
  35  *   clk: External oscillator clock frequency (default=16000000 [16 MHz])
  36  *   cir: CPU interface register (default=0x40 [DSC])
  37  *   bcr: Bus configuration register (default=0x40 [CBY])
  38  *   cor: Clockout register (default=0x00)
  39  *
  40  * Note: for clk, cir, bcr and cor, the first argument re-defines the
  41  * default for all other devices, e.g.:
  42  *
  43  *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000
  44  *
  45  * is equivalent to
  46  *
  47  *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
  48  */
  49
  50 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52 #include <linux/kernel.h>
  53 #include <linux/module.h>
  54 #include <linux/platform_device.h>
  55 #include <linux/interrupt.h>
  56 #include <linux/netdevice.h>
  57 #include <linux/delay.h>
  58 #include <linux/irq.h>
  59 #include <linux/io.h>
  60 #include <linux/can.h>
  61 #include <linux/can/dev.h>
  62 #include <linux/can/platform/cc770.h>
  63
  64 #include "cc770.h"
  65
  66 #define MAXDEV 8
  67
  68 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  69 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
  70 MODULE_LICENSE("GPL v2");
  71
  72 #define CLK_DEFAULT     16000000        /* 16 MHz */
  73 #define COR_DEFAULT     0x00
  74 #define BCR_DEFAULT     BUSCFG_CBY
  75
  76 static unsigned long port[MAXDEV];
  77 static unsigned long mem[MAXDEV];
  78 static int irq[MAXDEV];
  79 static int clk[MAXDEV];
  80 static u8 cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
  81 static u8 cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
  82 static u8 bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
  83 static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
  84
  85 module_param_hw_array(port, ulong, ioport, NULL, S_IRUGO);
  86 MODULE_PARM_DESC(port, "I/O port number");
  87
  88 module_param_hw_array(mem, ulong, iomem, NULL, S_IRUGO);
  89 MODULE_PARM_DESC(mem, "I/O memory address");
  90
  91 module_param_hw_array(indirect, int, ioport, NULL, S_IRUGO);
  92 MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
  93
  94 module_param_hw_array(irq, int, irq, NULL, S_IRUGO);
  95 MODULE_PARM_DESC(irq, "IRQ number");
  96
  97 module_param_array(clk, int, NULL, S_IRUGO);
  98 MODULE_PARM_DESC(clk, "External oscillator clock frequency "
  99                  "(default=16000000 [16 MHz])");
 100
 101 module_param_array(cir, byte, NULL, S_IRUGO);
 102 MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
 103
 104 module_param_array(cor, byte, NULL, S_IRUGO);
 105 MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
 106
 107 module_param_array(bcr, byte, NULL, S_IRUGO);
 108 MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
 109
 110 #define CC770_IOSIZE          0x20
 111 #define CC770_IOSIZE_INDIRECT 0x02
 112
 113 /* Spinlock for cc770_isa_port_write_reg_indirect
 114  * and cc770_isa_port_read_reg_indirect
 115  */
 116 static DEFINE_SPINLOCK(cc770_isa_port_lock);
 117
 118 static struct platform_device *cc770_isa_devs[MAXDEV];
 119
 120 static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
 121 {
 122         return readb(priv->reg_base + reg);
 123 }
 124
 125 static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
 126                                       int reg, u8 val)
 127 {
 128         writeb(val, priv->reg_base + reg);
 129 }
 130
 131 static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
 132 {
 133         return inb((unsigned long)priv->reg_base + reg);
 134 }
 135
 136 static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
 137                                        int reg, u8 val)
 138 {
 139         outb(val, (unsigned long)priv->reg_base + reg);
 140 }
 141
 142 static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
 143                                              int reg)
 144 {
 145         unsigned long base = (unsigned long)priv->reg_base;
 146         unsigned long flags;
 147         u8 val;
 148
 149         spin_lock_irqsave(&cc770_isa_port_lock, flags);
 150         outb(reg, base);
 151         val = inb(base + 1);
 152         spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
 153
 154         return val;
 155 }
 156
 157 static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
 158                                                 int reg, u8 val)
 159 {
 160         unsigned long base = (unsigned long)priv->reg_base;
 161         unsigned long flags;
 162
 163         spin_lock_irqsave(&cc770_isa_port_lock, flags);
 164         outb(reg, base);
 165         outb(val, base + 1);
 166         spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
 167 }
 168
 169 static int cc770_isa_probe(struct platform_device *pdev)
 170 {
 171         struct net_device *dev;
 172         struct cc770_priv *priv;
 173         void __iomem *base = NULL;
 174         int iosize = CC770_IOSIZE;
 175         int idx = pdev->id;
 176         int err;
 177         u32 clktmp;
 178
 179         dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
 180                 idx, port[idx], mem[idx], irq[idx]);
 181         if (mem[idx]) {
 182                 if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
 183                         err = -EBUSY;
 184                         goto exit;
 185                 }
 186                 base = ioremap_nocache(mem[idx], iosize);
 187                 if (!base) {
 188                         err = -ENOMEM;
 189                         goto exit_release;
 190                 }
 191         } else {
 192                 if (indirect[idx] > 0 ||
 193                     (indirect[idx] == -1 && indirect[0] > 0))
 194                         iosize = CC770_IOSIZE_INDIRECT;
 195                 if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
 196                         err = -EBUSY;
 197                         goto exit;
 198                 }
 199         }
 200
 201         dev = alloc_cc770dev(0);
 202         if (!dev) {
 203                 err = -ENOMEM;
 204                 goto exit_unmap;
 205         }
 206         priv = netdev_priv(dev);
 207
 208         dev->irq = irq[idx];
 209         priv->irq_flags = IRQF_SHARED;
 210         if (mem[idx]) {
 211                 priv->reg_base = base;
 212                 dev->base_addr = mem[idx];
 213                 priv->read_reg = cc770_isa_mem_read_reg;
 214                 priv->write_reg = cc770_isa_mem_write_reg;
 215         } else {
 216                 priv->reg_base = (void __iomem *)port[idx];
 217                 dev->base_addr = port[idx];
 218
 219                 if (iosize == CC770_IOSIZE_INDIRECT) {
 220                         priv->read_reg = cc770_isa_port_read_reg_indirect;
 221                         priv->write_reg = cc770_isa_port_write_reg_indirect;
 222                 } else {
 223                         priv->read_reg = cc770_isa_port_read_reg;
 224                         priv->write_reg = cc770_isa_port_write_reg;
 225                 }
 226         }
 227
 228         if (clk[idx])
 229                 clktmp = clk[idx];
 230         else if (clk[0])
 231                 clktmp = clk[0];
 232         else
 233                 clktmp = CLK_DEFAULT;
 234         priv->can.clock.freq = clktmp;
 235
 236         if (cir[idx] != 0xff) {
 237                 priv->cpu_interface = cir[idx];
 238         } else if (cir[0] != 0xff) {
 239                 priv->cpu_interface = cir[0];
 240         } else {
 241                 /* The system clock may not exceed 10 MHz */
 242                 if (clktmp > 10000000) {
 243                         priv->cpu_interface |= CPUIF_DSC;
 244                         clktmp /= 2;
 245                 }
 246                 /* The memory clock may not exceed 8 MHz */
 247                 if (clktmp > 8000000)
 248                         priv->cpu_interface |= CPUIF_DMC;
 249         }
 250
 251         if (priv->cpu_interface & CPUIF_DSC)
 252                 priv->can.clock.freq /= 2;
 253
 254         if (bcr[idx] != 0xff)
 255                 priv->bus_config = bcr[idx];
 256         else if (bcr[0] != 0xff)
 257                 priv->bus_config = bcr[0];
 258         else
 259                 priv->bus_config = BCR_DEFAULT;
 260
 261         if (cor[idx] != 0xff)
 262                 priv->clkout = cor[idx];
 263         else if (cor[0] != 0xff)
 264                 priv->clkout = cor[0];
 265         else
 266                 priv->clkout = COR_DEFAULT;
 267
 268         platform_set_drvdata(pdev, dev);
 269         SET_NETDEV_DEV(dev, &pdev->dev);
 270
 271         err = register_cc770dev(dev);
 272         if (err) {
 273                 dev_err(&pdev->dev,
 274                         "couldn't register device (err=%d)\n", err);
 275                 goto exit_unmap;
 276         }
 277
 278         dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
 279                  priv->reg_base, dev->irq);
 280         return 0;
 281
 282  exit_unmap:
 283         if (mem[idx])
 284                 iounmap(base);
 285  exit_release:
 286         if (mem[idx])
 287                 release_mem_region(mem[idx], iosize);
 288         else
 289                 release_region(port[idx], iosize);
 290  exit:
 291         return err;
 292 }
 293
 294 static int cc770_isa_remove(struct platform_device *pdev)
 295 {
 296         struct net_device *dev = platform_get_drvdata(pdev);
 297         struct cc770_priv *priv = netdev_priv(dev);
 298         int idx = pdev->id;
 299
 300         unregister_cc770dev(dev);
 301
 302         if (mem[idx]) {
 303                 iounmap(priv->reg_base);
 304                 release_mem_region(mem[idx], CC770_IOSIZE);
 305         } else {
 306                 if (priv->read_reg == cc770_isa_port_read_reg_indirect)
 307                         release_region(port[idx], CC770_IOSIZE_INDIRECT);
 308                 else
 309                         release_region(port[idx], CC770_IOSIZE);
 310         }
 311         free_cc770dev(dev);
 312
 313         return 0;
 314 }
 315
 316 static struct platform_driver cc770_isa_driver = {
 317         .probe = cc770_isa_probe,
 318         .remove = cc770_isa_remove,
 319         .driver = {
 320                 .name = KBUILD_MODNAME,
 321         },
 322 };
 323
 324 static int __init cc770_isa_init(void)
 325 {
 326         int idx, err;
 327
 328         for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
 329                 if ((port[idx] || mem[idx]) && irq[idx]) {
 330                         cc770_isa_devs[idx] =
 331                                 platform_device_alloc(KBUILD_MODNAME, idx);
 332                         if (!cc770_isa_devs[idx]) {
 333                                 err = -ENOMEM;
 334                                 goto exit_free_devices;
 335                         }
 336                         err = platform_device_add(cc770_isa_devs[idx]);
 337                         if (err) {
 338                                 platform_device_put(cc770_isa_devs[idx]);
 339                                 goto exit_free_devices;
 340                         }
 341                         pr_debug("platform device %d: port=%#lx, mem=%#lx, "
 342                                  "irq=%d\n",
 343                                  idx, port[idx], mem[idx], irq[idx]);
 344                 } else if (idx == 0 || port[idx] || mem[idx]) {
 345                         pr_err("insufficient parameters supplied\n");
 346                         err = -EINVAL;
 347                         goto exit_free_devices;
 348                 }
 349         }
 350
 351         err = platform_driver_register(&cc770_isa_driver);
 352         if (err)
 353                 goto exit_free_devices;
 354
 355         pr_info("driver for max. %d devices registered\n", MAXDEV);
 356
 357         return 0;
 358
 359 exit_free_devices:
 360         while (--idx >= 0) {
 361                 if (cc770_isa_devs[idx])
 362                         platform_device_unregister(cc770_isa_devs[idx]);
 363         }
 364
 365         return err;
 366 }
 367 module_init(cc770_isa_init);
 368
 369 static void __exit cc770_isa_exit(void)
 370 {
 371         int idx;
 372
 373         platform_driver_unregister(&cc770_isa_driver);
 374         for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
 375                 if (cc770_isa_devs[idx])
 376                         platform_device_unregister(cc770_isa_devs[idx]);
 377         }
 378 }
 379 module_exit(cc770_isa_exit);