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 /* References: 9 * - Getting started with TS-CAN1, Technologic Systems, Feb 2022 10 * https://docs.embeddedts.com/TS-CAN1 11 */ 12 13 #include <linux/init.h> 14 #include <linux/io.h> 15 #include <linux/ioport.h> 16 #include <linux/isa.h> 17 #include <linux/module.h> 18 #include <linux/netdevice.h> 19 #include "sja1000.h" 20 21 MODULE_DESCRIPTION("Driver for Technologic Systems TS-CAN1 PC104 boards"); 22 MODULE_AUTHOR("Andre B. Oliveira <anbadeol@gmail.com>"); 23 MODULE_LICENSE("GPL"); 24 25 /* Maximum number of boards (one in each JP1:JP2 setting of IO address) */ 26 #define TSCAN1_MAXDEV 4 27 28 /* PLD registers address offsets */ 29 #define TSCAN1_ID1 0 30 #define TSCAN1_ID2 1 31 #define TSCAN1_VERSION 2 32 #define TSCAN1_LED 3 33 #define TSCAN1_PAGE 4 34 #define TSCAN1_MODE 5 35 #define TSCAN1_JUMPERS 6 36 37 /* PLD board identifier registers magic values */ 38 #define TSCAN1_ID1_VALUE 0xf6 39 #define TSCAN1_ID2_VALUE 0xb9 40 41 /* PLD mode register SJA1000 IO enable bit */ 42 #define TSCAN1_MODE_ENABLE 0x40 43 44 /* PLD jumpers register bits */ 45 #define TSCAN1_JP4 0x10 46 #define TSCAN1_JP5 0x20 47 48 /* PLD IO base addresses start */ 49 #define TSCAN1_PLD_ADDRESS 0x150 50 51 /* PLD register space size */ 52 #define TSCAN1_PLD_SIZE 8 53 54 /* SJA1000 register space size */ 55 #define TSCAN1_SJA1000_SIZE 32 56 57 /* SJA1000 crystal frequency (16MHz) */ 58 #define TSCAN1_SJA1000_XTAL 16000000 59 60 /* SJA1000 IO base addresses */ 61 static const unsigned short tscan1_sja1000_addresses[] = { 62 0x100, 0x120, 0x180, 0x1a0, 0x200, 0x240, 0x280, 0x320 63 }; 64 65 /* Read SJA1000 register */ 66 static u8 tscan1_read(const struct sja1000_priv *priv, int reg) 67 { 68 return inb((unsigned long)priv->reg_base + reg); 69 } 70 71 /* Write SJA1000 register */ 72 static void tscan1_write(const struct sja1000_priv *priv, int reg, u8 val) 73 { 74 outb(val, (unsigned long)priv->reg_base + reg); 75 } 76 77 /* Probe for a TS-CAN1 board with JP2:JP1 jumper setting ID */ 78 static int tscan1_probe(struct device *dev, unsigned id) 79 { 80 struct net_device *netdev; 81 struct sja1000_priv *priv; 82 unsigned long pld_base, sja1000_base; 83 int irq, i; 84 85 pld_base = TSCAN1_PLD_ADDRESS + id * TSCAN1_PLD_SIZE; 86 if (!request_region(pld_base, TSCAN1_PLD_SIZE, dev_name(dev))) 87 return -EBUSY; 88 89 if (inb(pld_base + TSCAN1_ID1) != TSCAN1_ID1_VALUE || 90 inb(pld_base + TSCAN1_ID2) != TSCAN1_ID2_VALUE) { 91 release_region(pld_base, TSCAN1_PLD_SIZE); 92 return -ENODEV; 93 } 94 95 switch (inb(pld_base + TSCAN1_JUMPERS) & (TSCAN1_JP4 | TSCAN1_JP5)) { 96 case TSCAN1_JP4: 97 irq = 6; 98 break; 99 case TSCAN1_JP5: 100 irq = 7; 101 break; 102 case TSCAN1_JP4 | TSCAN1_JP5: 103 irq = 5; 104 break; 105 default: 106 dev_err(dev, "invalid JP4:JP5 setting (no IRQ)\n"); 107 release_region(pld_base, TSCAN1_PLD_SIZE); 108 return -EINVAL; 109 } 110 111 netdev = alloc_sja1000dev(0); 112 if (!netdev) { 113 release_region(pld_base, TSCAN1_PLD_SIZE); 114 return -ENOMEM; 115 } 116 117 dev_set_drvdata(dev, netdev); 118 SET_NETDEV_DEV(netdev, dev); 119 120 netdev->base_addr = pld_base; 121 netdev->irq = irq; 122 123 priv = netdev_priv(netdev); 124 priv->read_reg = tscan1_read; 125 priv->write_reg = tscan1_write; 126 priv->can.clock.freq = TSCAN1_SJA1000_XTAL / 2; 127 priv->cdr = CDR_CBP | CDR_CLK_OFF; 128 priv->ocr = OCR_TX0_PUSHPULL; 129 130 /* Select the first SJA1000 IO address that is free and that works */ 131 for (i = 0; i < ARRAY_SIZE(tscan1_sja1000_addresses); i++) { 132 sja1000_base = tscan1_sja1000_addresses[i]; 133 if (!request_region(sja1000_base, TSCAN1_SJA1000_SIZE, 134 dev_name(dev))) 135 continue; 136 137 /* Set SJA1000 IO base address and enable it */ 138 outb(TSCAN1_MODE_ENABLE | i, pld_base + TSCAN1_MODE); 139 140 priv->reg_base = (void __iomem *)sja1000_base; 141 if (!register_sja1000dev(netdev)) { 142 /* SJA1000 probe succeeded; turn LED off and return */ 143 outb(0, pld_base + TSCAN1_LED); 144 netdev_info(netdev, "TS-CAN1 at 0x%lx 0x%lx irq %d\n", 145 pld_base, sja1000_base, irq); 146 return 0; 147 } 148 149 /* SJA1000 probe failed; release and try next address */ 150 outb(0, pld_base + TSCAN1_MODE); 151 release_region(sja1000_base, TSCAN1_SJA1000_SIZE); 152 } 153 154 dev_err(dev, "failed to assign SJA1000 IO address\n"); 155 dev_set_drvdata(dev, NULL); 156 free_sja1000dev(netdev); 157 release_region(pld_base, TSCAN1_PLD_SIZE); 158 return -ENXIO; 159 } 160 161 static void tscan1_remove(struct device *dev, unsigned id /*unused*/) 162 { 163 struct net_device *netdev; 164 struct sja1000_priv *priv; 165 unsigned long pld_base, sja1000_base; 166 167 netdev = dev_get_drvdata(dev); 168 unregister_sja1000dev(netdev); 169 dev_set_drvdata(dev, NULL); 170 171 priv = netdev_priv(netdev); 172 pld_base = netdev->base_addr; 173 sja1000_base = (unsigned long)priv->reg_base; 174 175 outb(0, pld_base + TSCAN1_MODE); /* disable SJA1000 IO space */ 176 177 release_region(sja1000_base, TSCAN1_SJA1000_SIZE); 178 release_region(pld_base, TSCAN1_PLD_SIZE); 179 180 free_sja1000dev(netdev); 181 } 182 183 static struct isa_driver tscan1_isa_driver = { 184 .probe = tscan1_probe, 185 .remove = tscan1_remove, 186 .driver = { 187 .name = "tscan1", 188 }, 189 }; 190 191 module_isa_driver(tscan1_isa_driver, TSCAN1_MAXDEV); 192