linux/drivers/net/can/cc770/cc770_isa.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Driver for CC770 and AN82527 CAN controllers on the legacy ISA bus
   4 *
   5 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
   6 */
   7
   8/*
   9 * Bosch CC770 and Intel AN82527 CAN controllers on the ISA or PC-104 bus.
  10 * The I/O port or memory address and the IRQ number must be specified via
  11 * module parameters:
  12 *
  13 *   insmod cc770_isa.ko port=0x310,0x380 irq=7,11
  14 *
  15 * for ISA devices using I/O ports or:
  16 *
  17 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11
  18 *
  19 * for memory mapped ISA devices.
  20 *
  21 * Indirect access via address and data port is supported as well:
  22 *
  23 *   insmod cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11
  24 *
  25 * Furthermore, the following mode parameter can be defined:
  26 *
  27 *   clk: External oscillator clock frequency (default=16000000 [16 MHz])
  28 *   cir: CPU interface register (default=0x40 [DSC])
  29 *   bcr: Bus configuration register (default=0x40 [CBY])
  30 *   cor: Clockout register (default=0x00)
  31 *
  32 * Note: for clk, cir, bcr and cor, the first argument re-defines the
  33 * default for all other devices, e.g.:
  34 *
  35 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000
  36 *
  37 * is equivalent to
  38 *
  39 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
  40 */
  41
  42#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  43
  44#include <linux/kernel.h>
  45#include <linux/module.h>
  46#include <linux/platform_device.h>
  47#include <linux/interrupt.h>
  48#include <linux/netdevice.h>
  49#include <linux/delay.h>
  50#include <linux/irq.h>
  51#include <linux/io.h>
  52#include <linux/can.h>
  53#include <linux/can/dev.h>
  54#include <linux/can/platform/cc770.h>
  55
  56#include "cc770.h"
  57
  58#define MAXDEV 8
  59
  60MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  61MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
  62MODULE_LICENSE("GPL v2");
  63
  64#define CLK_DEFAULT     16000000        /* 16 MHz */
  65#define COR_DEFAULT     0x00
  66#define BCR_DEFAULT     BUSCFG_CBY
  67
  68static unsigned long port[MAXDEV];
  69static unsigned long mem[MAXDEV];
  70static int irq[MAXDEV];
  71static int clk[MAXDEV];
  72static u8 cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
  73static u8 cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
  74static u8 bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
  75static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
  76
  77module_param_hw_array(port, ulong, ioport, NULL, 0444);
  78MODULE_PARM_DESC(port, "I/O port number");
  79
  80module_param_hw_array(mem, ulong, iomem, NULL, 0444);
  81MODULE_PARM_DESC(mem, "I/O memory address");
  82
  83module_param_hw_array(indirect, int, ioport, NULL, 0444);
  84MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
  85
  86module_param_hw_array(irq, int, irq, NULL, 0444);
  87MODULE_PARM_DESC(irq, "IRQ number");
  88
  89module_param_array(clk, int, NULL, 0444);
  90MODULE_PARM_DESC(clk, "External oscillator clock frequency "
  91                 "(default=16000000 [16 MHz])");
  92
  93module_param_array(cir, byte, NULL, 0444);
  94MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
  95
  96module_param_array(cor, byte, NULL, 0444);
  97MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
  98
  99module_param_array(bcr, byte, NULL, 0444);
 100MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
 101
 102#define CC770_IOSIZE          0x20
 103#define CC770_IOSIZE_INDIRECT 0x02
 104
 105/* Spinlock for cc770_isa_port_write_reg_indirect
 106 * and cc770_isa_port_read_reg_indirect
 107 */
 108static DEFINE_SPINLOCK(cc770_isa_port_lock);
 109
 110static struct platform_device *cc770_isa_devs[MAXDEV];
 111
 112static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
 113{
 114        return readb(priv->reg_base + reg);
 115}
 116
 117static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
 118                                      int reg, u8 val)
 119{
 120        writeb(val, priv->reg_base + reg);
 121}
 122
 123static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
 124{
 125        return inb((unsigned long)priv->reg_base + reg);
 126}
 127
 128static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
 129                                       int reg, u8 val)
 130{
 131        outb(val, (unsigned long)priv->reg_base + reg);
 132}
 133
 134static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
 135                                             int reg)
 136{
 137        unsigned long base = (unsigned long)priv->reg_base;
 138        unsigned long flags;
 139        u8 val;
 140
 141        spin_lock_irqsave(&cc770_isa_port_lock, flags);
 142        outb(reg, base);
 143        val = inb(base + 1);
 144        spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
 145
 146        return val;
 147}
 148
 149static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
 150                                                int reg, u8 val)
 151{
 152        unsigned long base = (unsigned long)priv->reg_base;
 153        unsigned long flags;
 154
 155        spin_lock_irqsave(&cc770_isa_port_lock, flags);
 156        outb(reg, base);
 157        outb(val, base + 1);
 158        spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
 159}
 160
 161static int cc770_isa_probe(struct platform_device *pdev)
 162{
 163        struct net_device *dev;
 164        struct cc770_priv *priv;
 165        void __iomem *base = NULL;
 166        int iosize = CC770_IOSIZE;
 167        int idx = pdev->id;
 168        int err;
 169        u32 clktmp;
 170
 171        dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
 172                idx, port[idx], mem[idx], irq[idx]);
 173        if (mem[idx]) {
 174                if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
 175                        err = -EBUSY;
 176                        goto exit;
 177                }
 178                base = ioremap_nocache(mem[idx], iosize);
 179                if (!base) {
 180                        err = -ENOMEM;
 181                        goto exit_release;
 182                }
 183        } else {
 184                if (indirect[idx] > 0 ||
 185                    (indirect[idx] == -1 && indirect[0] > 0))
 186                        iosize = CC770_IOSIZE_INDIRECT;
 187                if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
 188                        err = -EBUSY;
 189                        goto exit;
 190                }
 191        }
 192
 193        dev = alloc_cc770dev(0);
 194        if (!dev) {
 195                err = -ENOMEM;
 196                goto exit_unmap;
 197        }
 198        priv = netdev_priv(dev);
 199
 200        dev->irq = irq[idx];
 201        priv->irq_flags = IRQF_SHARED;
 202        if (mem[idx]) {
 203                priv->reg_base = base;
 204                dev->base_addr = mem[idx];
 205                priv->read_reg = cc770_isa_mem_read_reg;
 206                priv->write_reg = cc770_isa_mem_write_reg;
 207        } else {
 208                priv->reg_base = (void __iomem *)port[idx];
 209                dev->base_addr = port[idx];
 210
 211                if (iosize == CC770_IOSIZE_INDIRECT) {
 212                        priv->read_reg = cc770_isa_port_read_reg_indirect;
 213                        priv->write_reg = cc770_isa_port_write_reg_indirect;
 214                } else {
 215                        priv->read_reg = cc770_isa_port_read_reg;
 216                        priv->write_reg = cc770_isa_port_write_reg;
 217                }
 218        }
 219
 220        if (clk[idx])
 221                clktmp = clk[idx];
 222        else if (clk[0])
 223                clktmp = clk[0];
 224        else
 225                clktmp = CLK_DEFAULT;
 226        priv->can.clock.freq = clktmp;
 227
 228        if (cir[idx] != 0xff) {
 229                priv->cpu_interface = cir[idx];
 230        } else if (cir[0] != 0xff) {
 231                priv->cpu_interface = cir[0];
 232        } else {
 233                /* The system clock may not exceed 10 MHz */
 234                if (clktmp > 10000000) {
 235                        priv->cpu_interface |= CPUIF_DSC;
 236                        clktmp /= 2;
 237                }
 238                /* The memory clock may not exceed 8 MHz */
 239                if (clktmp > 8000000)
 240                        priv->cpu_interface |= CPUIF_DMC;
 241        }
 242
 243        if (priv->cpu_interface & CPUIF_DSC)
 244                priv->can.clock.freq /= 2;
 245
 246        if (bcr[idx] != 0xff)
 247                priv->bus_config = bcr[idx];
 248        else if (bcr[0] != 0xff)
 249                priv->bus_config = bcr[0];
 250        else
 251                priv->bus_config = BCR_DEFAULT;
 252
 253        if (cor[idx] != 0xff)
 254                priv->clkout = cor[idx];
 255        else if (cor[0] != 0xff)
 256                priv->clkout = cor[0];
 257        else
 258                priv->clkout = COR_DEFAULT;
 259
 260        platform_set_drvdata(pdev, dev);
 261        SET_NETDEV_DEV(dev, &pdev->dev);
 262
 263        err = register_cc770dev(dev);
 264        if (err) {
 265                dev_err(&pdev->dev,
 266                        "couldn't register device (err=%d)\n", err);
 267                goto exit_unmap;
 268        }
 269
 270        dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
 271                 priv->reg_base, dev->irq);
 272        return 0;
 273
 274 exit_unmap:
 275        if (mem[idx])
 276                iounmap(base);
 277 exit_release:
 278        if (mem[idx])
 279                release_mem_region(mem[idx], iosize);
 280        else
 281                release_region(port[idx], iosize);
 282 exit:
 283        return err;
 284}
 285
 286static int cc770_isa_remove(struct platform_device *pdev)
 287{
 288        struct net_device *dev = platform_get_drvdata(pdev);
 289        struct cc770_priv *priv = netdev_priv(dev);
 290        int idx = pdev->id;
 291
 292        unregister_cc770dev(dev);
 293
 294        if (mem[idx]) {
 295                iounmap(priv->reg_base);
 296                release_mem_region(mem[idx], CC770_IOSIZE);
 297        } else {
 298                if (priv->read_reg == cc770_isa_port_read_reg_indirect)
 299                        release_region(port[idx], CC770_IOSIZE_INDIRECT);
 300                else
 301                        release_region(port[idx], CC770_IOSIZE);
 302        }
 303        free_cc770dev(dev);
 304
 305        return 0;
 306}
 307
 308static struct platform_driver cc770_isa_driver = {
 309        .probe = cc770_isa_probe,
 310        .remove = cc770_isa_remove,
 311        .driver = {
 312                .name = KBUILD_MODNAME,
 313        },
 314};
 315
 316static int __init cc770_isa_init(void)
 317{
 318        int idx, err;
 319
 320        for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
 321                if ((port[idx] || mem[idx]) && irq[idx]) {
 322                        cc770_isa_devs[idx] =
 323                                platform_device_alloc(KBUILD_MODNAME, idx);
 324                        if (!cc770_isa_devs[idx]) {
 325                                err = -ENOMEM;
 326                                goto exit_free_devices;
 327                        }
 328                        err = platform_device_add(cc770_isa_devs[idx]);
 329                        if (err) {
 330                                platform_device_put(cc770_isa_devs[idx]);
 331                                goto exit_free_devices;
 332                        }
 333                        pr_debug("platform device %d: port=%#lx, mem=%#lx, "
 334                                 "irq=%d\n",
 335                                 idx, port[idx], mem[idx], irq[idx]);
 336                } else if (idx == 0 || port[idx] || mem[idx]) {
 337                        pr_err("insufficient parameters supplied\n");
 338                        err = -EINVAL;
 339                        goto exit_free_devices;
 340                }
 341        }
 342
 343        err = platform_driver_register(&cc770_isa_driver);
 344        if (err)
 345                goto exit_free_devices;
 346
 347        pr_info("driver for max. %d devices registered\n", MAXDEV);
 348
 349        return 0;
 350
 351exit_free_devices:
 352        while (--idx >= 0) {
 353                if (cc770_isa_devs[idx])
 354                        platform_device_unregister(cc770_isa_devs[idx]);
 355        }
 356
 357        return err;
 358}
 359module_init(cc770_isa_init);
 360
 361static void __exit cc770_isa_exit(void)
 362{
 363        int idx;
 364
 365        platform_driver_unregister(&cc770_isa_driver);
 366        for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
 367                if (cc770_isa_devs[idx])
 368                        platform_device_unregister(cc770_isa_devs[idx]);
 369        }
 370}
 371module_exit(cc770_isa_exit);
 372