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
  22 MODULE_DESCRIPTION("Driver for Technologic Systems TS-CAN1 PC104 boards");
  23 MODULE_AUTHOR("Andre B. Oliveira <anbadeol@gmail.com>");
  24 MODULE_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 */
  62 static const unsigned short tscan1_sja1000_addresses[] = {
  63         0x100, 0x120, 0x180, 0x1a0, 0x200, 0x240, 0x280, 0x320
  64 };
  65
  66 /* Read SJA1000 register */
  67 static 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 */
  73 static 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 */
  79 static 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
 162 static int 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         return 0;
 184 }
 185
 186 static struct isa_driver tscan1_isa_driver = {
 187         .probe = tscan1_probe,
 188         .remove = tscan1_remove,
 189         .driver = {
 190                 .name = "tscan1",
 191         },
 192 };
 193
 194 module_isa_driver(tscan1_isa_driver, TSCAN1_MAXDEV);