tscan1.c revision 2d3359f8b9e6b3d6339b7e72f8e82275058eb13c 
1/*
2 * tscan1.c: driver for Technologic Systems TS-CAN1 PC104 boards
3 *
4 * Copyright 2010 Andre B. Oliveira
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20/*
21 * References:
22 * - Getting started with TS-CAN1, Technologic Systems, Jun 2009
23 *	http://www.embeddedarm.com/documentation/ts-can1-manual.pdf
24 */
25
26#include <linux/init.h>
27#include <linux/io.h>
28#include <linux/ioport.h>
29#include <linux/isa.h>
30#include <linux/module.h>
31#include <linux/netdevice.h>
32#include "sja1000.h"
33
34MODULE_DESCRIPTION("Driver for Technologic Systems TS-CAN1 PC104 boards");
35MODULE_AUTHOR("Andre B. Oliveira <anbadeol@gmail.com>");
36MODULE_LICENSE("GPL");
37
38/* Maximum number of boards (one in each JP1:JP2 setting of IO address) */
39#define TSCAN1_MAXDEV 4
40
41/* PLD registers address offsets */
42#define TSCAN1_ID1	0
43#define TSCAN1_ID2	1
44#define TSCAN1_VERSION	2
45#define TSCAN1_LED	3
46#define TSCAN1_PAGE	4
47#define TSCAN1_MODE	5
48#define TSCAN1_JUMPERS	6
49
50/* PLD board identifier registers magic values */
51#define TSCAN1_ID1_VALUE 0xf6
52#define TSCAN1_ID2_VALUE 0xb9
53
54/* PLD mode register SJA1000 IO enable bit */
55#define TSCAN1_MODE_ENABLE 0x40
56
57/* PLD jumpers register bits */
58#define TSCAN1_JP4 0x10
59#define TSCAN1_JP5 0x20
60
61/* PLD IO base addresses start */
62#define TSCAN1_PLD_ADDRESS 0x150
63
64/* PLD register space size */
65#define TSCAN1_PLD_SIZE 8
66
67/* SJA1000 register space size */
68#define TSCAN1_SJA1000_SIZE 32
69
70/* SJA1000 crystal frequency (16MHz) */
71#define TSCAN1_SJA1000_XTAL 16000000
72
73/* SJA1000 IO base addresses */
74static const unsigned short tscan1_sja1000_addresses[] __devinitconst = {
75	0x100, 0x120, 0x180, 0x1a0, 0x200, 0x240, 0x280, 0x320
76};
77
78/* Read SJA1000 register */
79static u8 tscan1_read(const struct sja1000_priv *priv, int reg)
80{
81	return inb((unsigned long)priv->reg_base + reg);
82}
83
84/* Write SJA1000 register */
85static void tscan1_write(const struct sja1000_priv *priv, int reg, u8 val)
86{
87	outb(val, (unsigned long)priv->reg_base + reg);
88}
89
90/* Probe for a TS-CAN1 board with JP2:JP1 jumper setting ID */
91static int __devinit tscan1_probe(struct device *dev, unsigned id)
92{
93	struct net_device *netdev;
94	struct sja1000_priv *priv;
95	unsigned long pld_base, sja1000_base;
96	int irq, i;
97
98	pld_base = TSCAN1_PLD_ADDRESS + id * TSCAN1_PLD_SIZE;
99	if (!request_region(pld_base, TSCAN1_PLD_SIZE, dev_name(dev)))
100		return -EBUSY;
101
102	if (inb(pld_base + TSCAN1_ID1) != TSCAN1_ID1_VALUE ||
103	    inb(pld_base + TSCAN1_ID2) != TSCAN1_ID2_VALUE) {
104		release_region(pld_base, TSCAN1_PLD_SIZE);
105		return -ENODEV;
106	}
107
108	switch (inb(pld_base + TSCAN1_JUMPERS) & (TSCAN1_JP4 | TSCAN1_JP5)) {
109	case TSCAN1_JP4:
110		irq = 6;
111		break;
112	case TSCAN1_JP5:
113		irq = 7;
114		break;
115	case TSCAN1_JP4 | TSCAN1_JP5:
116		irq = 5;
117		break;
118	default:
119		dev_err(dev, "invalid JP4:JP5 setting (no IRQ)\n");
120		release_region(pld_base, TSCAN1_PLD_SIZE);
121		return -EINVAL;
122	}
123
124	netdev = alloc_sja1000dev(0);
125	if (!netdev) {
126		release_region(pld_base, TSCAN1_PLD_SIZE);
127		return -ENOMEM;
128	}
129
130	dev_set_drvdata(dev, netdev);
131	SET_NETDEV_DEV(netdev, dev);
132
133	netdev->base_addr = pld_base;
134	netdev->irq = irq;
135
136	priv = netdev_priv(netdev);
137	priv->read_reg = tscan1_read;
138	priv->write_reg = tscan1_write;
139	priv->can.clock.freq = TSCAN1_SJA1000_XTAL / 2;
140	priv->cdr = CDR_CBP | CDR_CLK_OFF;
141	priv->ocr = OCR_TX0_PUSHPULL;
142
143	/* Select the first SJA1000 IO address that is free and that works */
144	for (i = 0; i < ARRAY_SIZE(tscan1_sja1000_addresses); i++) {
145		sja1000_base = tscan1_sja1000_addresses[i];
146		if (!request_region(sja1000_base, TSCAN1_SJA1000_SIZE,
147								dev_name(dev)))
148			continue;
149
150		/* Set SJA1000 IO base address and enable it */
151		outb(TSCAN1_MODE_ENABLE | i, pld_base + TSCAN1_MODE);
152
153		priv->reg_base = (void __iomem *)sja1000_base;
154		if (!register_sja1000dev(netdev)) {
155			/* SJA1000 probe succeeded; turn LED off and return */
156			outb(0, pld_base + TSCAN1_LED);
157			netdev_info(netdev, "TS-CAN1 at 0x%lx 0x%lx irq %d\n",
158						pld_base, sja1000_base, irq);
159			return 0;
160		}
161
162		/* SJA1000 probe failed; release and try next address */
163		outb(0, pld_base + TSCAN1_MODE);
164		release_region(sja1000_base, TSCAN1_SJA1000_SIZE);
165	}
166
167	dev_err(dev, "failed to assign SJA1000 IO address\n");
168	dev_set_drvdata(dev, NULL);
169	free_sja1000dev(netdev);
170	release_region(pld_base, TSCAN1_PLD_SIZE);
171	return -ENXIO;
172}
173
174static int __devexit tscan1_remove(struct device *dev, unsigned id /*unused*/)
175{
176	struct net_device *netdev;
177	struct sja1000_priv *priv;
178	unsigned long pld_base, sja1000_base;
179
180	netdev = dev_get_drvdata(dev);
181	unregister_sja1000dev(netdev);
182	dev_set_drvdata(dev, NULL);
183
184	priv = netdev_priv(netdev);
185	pld_base = netdev->base_addr;
186	sja1000_base = (unsigned long)priv->reg_base;
187
188	outb(0, pld_base + TSCAN1_MODE);	/* disable SJA1000 IO space */
189
190	release_region(sja1000_base, TSCAN1_SJA1000_SIZE);
191	release_region(pld_base, TSCAN1_PLD_SIZE);
192
193	free_sja1000dev(netdev);
194
195	return 0;
196}
197
198static struct isa_driver tscan1_isa_driver = {
199	.probe = tscan1_probe,
200	.remove = __devexit_p(tscan1_remove),
201	.driver = {
202		.name = "tscan1",
203	},
204};
205
206static int __init tscan1_init(void)
207{
208	return isa_register_driver(&tscan1_isa_driver, TSCAN1_MAXDEV);
209}
210module_init(tscan1_init);
211
212static void __exit tscan1_exit(void)
213{
214	isa_unregister_driver(&tscan1_isa_driver);
215}
216module_exit(tscan1_exit);
217