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 */
tscan1_read(const struct sja1000_priv * priv,int reg)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 */
tscan1_write(const struct sja1000_priv * priv,int reg,u8 val)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 */
tscan1_probe(struct device * dev,unsigned 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
tscan1_remove(struct device * dev,unsigned id)162 static 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
184 static struct isa_driver tscan1_isa_driver = {
185 .probe = tscan1_probe,
186 .remove = tscan1_remove,
187 .driver = {
188 .name = "tscan1",
189 },
190 };
191
192 module_isa_driver(tscan1_isa_driver, TSCAN1_MAXDEV);
193
