LXR linux/drivers/net/can/sja1000/tscan1.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * tscan1.c: driver for Technologic Systems TS-CAN1 PC104 boards
   4 *
   5 * Copyright 2010 Andre B. Oliveira
   6 */
   7
   8/*
   9 * References:
  10 * - Getting started with TS-CAN1, Technologic Systems, Jun 2009
  11 *      http://www.embeddedarm.com/documentation/ts-can1-manual.pdf
  12 */
  13
  14#include <linux/init.h>
  15#include <linux/io.h>
  16#include <linux/ioport.h>
  17#include <linux/isa.h>
  18#include <linux/module.h>
  19#include <linux/netdevice.h>
  20#include "sja1000.h"
  21
  22MODULE_DESCRIPTION("Driver for Technologic Systems TS-CAN1 PC104 boards");
  23MODULE_AUTHOR("Andre B. Oliveira <anbadeol@gmail.com>");
  24MODULE_LICENSE("GPL");
  25
  26/* Maximum number of boards (one in each JP1:JP2 setting of IO address) */
  27#define TSCAN1_MAXDEV 4
  28
  29/* PLD registers address offsets */
  30#define TSCAN1_ID1      0
  31#define TSCAN1_ID2      1
  32#define TSCAN1_VERSION  2
  33#define TSCAN1_LED      3
  34#define TSCAN1_PAGE     4
  35#define TSCAN1_MODE     5
  36#define TSCAN1_JUMPERS  6
  37
  38/* PLD board identifier registers magic values */
  39#define TSCAN1_ID1_VALUE 0xf6
  40#define TSCAN1_ID2_VALUE 0xb9
  41
  42/* PLD mode register SJA1000 IO enable bit */
  43#define TSCAN1_MODE_ENABLE 0x40
  44
  45/* PLD jumpers register bits */
  46#define TSCAN1_JP4 0x10
  47#define TSCAN1_JP5 0x20
  48
  49/* PLD IO base addresses start */
  50#define TSCAN1_PLD_ADDRESS 0x150
  51
  52/* PLD register space size */
  53#define TSCAN1_PLD_SIZE 8
  54
  55/* SJA1000 register space size */
  56#define TSCAN1_SJA1000_SIZE 32
  57
  58/* SJA1000 crystal frequency (16MHz) */
  59#define TSCAN1_SJA1000_XTAL 16000000
  60
  61/* SJA1000 IO base addresses */
  62static const unsigned short tscan1_sja1000_addresses[] = {
  63        0x100, 0x120, 0x180, 0x1a0, 0x200, 0x240, 0x280, 0x320
  64};
  65
  66/* Read SJA1000 register */
  67static u8 tscan1_read(const struct sja1000_priv *priv, int reg)
  68{
  69        return inb((unsigned long)priv->reg_base + reg);
  70}
  71
  72/* Write SJA1000 register */
  73static void tscan1_write(const struct sja1000_priv *priv, int reg, u8 val)
  74{
  75        outb(val, (unsigned long)priv->reg_base + reg);
  76}
  77
  78/* Probe for a TS-CAN1 board with JP2:JP1 jumper setting ID */
  79static int tscan1_probe(struct device *dev, unsigned id)
  80{
  81        struct net_device *netdev;
  82        struct sja1000_priv *priv;
  83        unsigned long pld_base, sja1000_base;
  84        int irq, i;
  85
  86        pld_base = TSCAN1_PLD_ADDRESS + id * TSCAN1_PLD_SIZE;
  87        if (!request_region(pld_base, TSCAN1_PLD_SIZE, dev_name(dev)))
  88                return -EBUSY;
  89
  90        if (inb(pld_base + TSCAN1_ID1) != TSCAN1_ID1_VALUE ||
  91            inb(pld_base + TSCAN1_ID2) != TSCAN1_ID2_VALUE) {
  92                release_region(pld_base, TSCAN1_PLD_SIZE);
  93                return -ENODEV;
  94        }
  95
  96        switch (inb(pld_base + TSCAN1_JUMPERS) & (TSCAN1_JP4 | TSCAN1_JP5)) {
  97        case TSCAN1_JP4:
  98                irq = 6;
  99                break;
 100        case TSCAN1_JP5:
 101                irq = 7;
 102                break;
 103        case TSCAN1_JP4 | TSCAN1_JP5:
 104                irq = 5;
 105                break;
 106        default:
 107                dev_err(dev, "invalid JP4:JP5 setting (no IRQ)\n");
 108                release_region(pld_base, TSCAN1_PLD_SIZE);
 109                return -EINVAL;
 110        }
 111
 112        netdev = alloc_sja1000dev(0);
 113        if (!netdev) {
 114                release_region(pld_base, TSCAN1_PLD_SIZE);
 115                return -ENOMEM;
 116        }
 117
 118        dev_set_drvdata(dev, netdev);
 119        SET_NETDEV_DEV(netdev, dev);
 120
 121        netdev->base_addr = pld_base;
 122        netdev->irq = irq;
 123
 124        priv = netdev_priv(netdev);
 125        priv->read_reg = tscan1_read;
 126        priv->write_reg = tscan1_write;
 127        priv->can.clock.freq = TSCAN1_SJA1000_XTAL / 2;
 128        priv->cdr = CDR_CBP | CDR_CLK_OFF;
 129        priv->ocr = OCR_TX0_PUSHPULL;
 130
 131        /* Select the first SJA1000 IO address that is free and that works */
 132        for (i = 0; i < ARRAY_SIZE(tscan1_sja1000_addresses); i++) {
 133                sja1000_base = tscan1_sja1000_addresses[i];
 134                if (!request_region(sja1000_base, TSCAN1_SJA1000_SIZE,
 135                                                                dev_name(dev)))
 136                        continue;
 137
 138                /* Set SJA1000 IO base address and enable it */
 139                outb(TSCAN1_MODE_ENABLE | i, pld_base + TSCAN1_MODE);
 140
 141                priv->reg_base = (void __iomem *)sja1000_base;
 142                if (!register_sja1000dev(netdev)) {
 143                        /* SJA1000 probe succeeded; turn LED off and return */
 144                        outb(0, pld_base + TSCAN1_LED);
 145                        netdev_info(netdev, "TS-CAN1 at 0x%lx 0x%lx irq %d\n",
 146                                                pld_base, sja1000_base, irq);
 147                        return 0;
 148                }
 149
 150                /* SJA1000 probe failed; release and try next address */
 151                outb(0, pld_base + TSCAN1_MODE);
 152                release_region(sja1000_base, TSCAN1_SJA1000_SIZE);
 153        }
 154
 155        dev_err(dev, "failed to assign SJA1000 IO address\n");
 156        dev_set_drvdata(dev, NULL);
 157        free_sja1000dev(netdev);
 158        release_region(pld_base, TSCAN1_PLD_SIZE);
 159        return -ENXIO;
 160}
 161
 162static void tscan1_remove(struct device *dev, unsigned id /*unused*/)
 163{
 164        struct net_device *netdev;
 165        struct sja1000_priv *priv;
 166        unsigned long pld_base, sja1000_base;
 167
 168        netdev = dev_get_drvdata(dev);
 169        unregister_sja1000dev(netdev);
 170        dev_set_drvdata(dev, NULL);
 171
 172        priv = netdev_priv(netdev);
 173        pld_base = netdev->base_addr;
 174        sja1000_base = (unsigned long)priv->reg_base;
 175
 176        outb(0, pld_base + TSCAN1_MODE);        /* disable SJA1000 IO space */
 177
 178        release_region(sja1000_base, TSCAN1_SJA1000_SIZE);
 179        release_region(pld_base, TSCAN1_PLD_SIZE);
 180
 181        free_sja1000dev(netdev);
 182}
 183
 184static struct isa_driver tscan1_isa_driver = {
 185        .probe = tscan1_probe,
 186        .remove = tscan1_remove,
 187        .driver = {
 188                .name = "tscan1",
 189        },
 190};
 191
 192module_isa_driver(tscan1_isa_driver, TSCAN1_MAXDEV);
 193