summaryrefslogtreecommitdiffstats
path: root/drivers/net/can/cc770/cc770_isa.c
blob: e0d15711e9ac2ae7981247400d0f294eb1c9da37 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
/*
 * Driver for CC770 and AN82527 CAN controllers on the legacy ISA bus
 *
 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

/*
 * Bosch CC770 and Intel AN82527 CAN controllers on the ISA or PC-104 bus.
 * The I/O port or memory address and the IRQ number must be specified via
 * module parameters:
 *
 *   insmod cc770_isa.ko port=0x310,0x380 irq=7,11
 *
 * for ISA devices using I/O ports or:
 *
 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11
 *
 * for memory mapped ISA devices.
 *
 * Indirect access via address and data port is supported as well:
 *
 *   insmod cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11
 *
 * Furthermore, the following mode parameter can be defined:
 *
 *   clk: External oscillator clock frequency (default=16000000 [16 MHz])
 *   cir: CPU interface register (default=0x40 [DSC])
 *   bcr: Bus configuration register (default=0x40 [CBY])
 *   cor: Clockout register (default=0x00)
 *
 * Note: for clk, cir, bcr and cor, the first argument re-defines the
 * default for all other devices, e.g.:
 *
 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000
 *
 * is equivalent to
 *
 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/platform/cc770.h>

#include "cc770.h"

#define MAXDEV 8

MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
MODULE_LICENSE("GPL v2");

#define CLK_DEFAULT	16000000	/* 16 MHz */
#define COR_DEFAULT	0x00
#define BCR_DEFAULT	BUSCFG_CBY

static unsigned long port[MAXDEV];
static unsigned long mem[MAXDEV];
static int irq[MAXDEV];
static int clk[MAXDEV];
static u8 cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
static u8 cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
static u8 bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};

module_param_array(port, ulong, NULL, S_IRUGO);
MODULE_PARM_DESC(port, "I/O port number");

module_param_array(mem, ulong, NULL, S_IRUGO);
MODULE_PARM_DESC(mem, "I/O memory address");

module_param_array(indirect, int, NULL, S_IRUGO);
MODULE_PARM_DESC(indirect, "Indirect access via address and data port");

module_param_array(irq, int, NULL, S_IRUGO);
MODULE_PARM_DESC(irq, "IRQ number");

module_param_array(clk, int, NULL, S_IRUGO);
MODULE_PARM_DESC(clk, "External oscillator clock frequency "
		 "(default=16000000 [16 MHz])");

module_param_array(cir, byte, NULL, S_IRUGO);
MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");

module_param_array(cor, byte, NULL, S_IRUGO);
MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");

module_param_array(bcr, byte, NULL, S_IRUGO);
MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");

#define CC770_IOSIZE          0x20
#define CC770_IOSIZE_INDIRECT 0x02

/* Spinlock for cc770_isa_port_write_reg_indirect
 * and cc770_isa_port_read_reg_indirect
 */
static DEFINE_SPINLOCK(cc770_isa_port_lock);

static struct platform_device *cc770_isa_devs[MAXDEV];

static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
{
	return readb(priv->reg_base + reg);
}

static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
				      int reg, u8 val)
{
	writeb(val, priv->reg_base + reg);
}

static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
{
	return inb((unsigned long)priv->reg_base + reg);
}

static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
				       int reg, u8 val)
{
	outb(val, (unsigned long)priv->reg_base + reg);
}

static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
					     int reg)
{
	unsigned long base = (unsigned long)priv->reg_base;
	unsigned long flags;
	u8 val;

	spin_lock_irqsave(&cc770_isa_port_lock, flags);
	outb(reg, base);
	val = inb(base + 1);
	spin_unlock_irqrestore(&cc770_isa_port_lock, flags);

	return val;
}

static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
						int reg, u8 val)
{
	unsigned long base = (unsigned long)priv->reg_base;
	unsigned long flags;

	spin_lock_irqsave(&cc770_isa_port_lock, flags);
	outb(reg, base);
	outb(val, base + 1);
	spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
}

static int cc770_isa_probe(struct platform_device *pdev)
{
	struct net_device *dev;
	struct cc770_priv *priv;
	void __iomem *base = NULL;
	int iosize = CC770_IOSIZE;
	int idx = pdev->id;
	int err;
	u32 clktmp;

	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
		idx, port[idx], mem[idx], irq[idx]);
	if (mem[idx]) {
		if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
			err = -EBUSY;
			goto exit;
		}
		base = ioremap_nocache(mem[idx], iosize);
		if (!base) {
			err = -ENOMEM;
			goto exit_release;
		}
	} else {
		if (indirect[idx] > 0 ||
		    (indirect[idx] == -1 && indirect[0] > 0))
			iosize = CC770_IOSIZE_INDIRECT;
		if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
			err = -EBUSY;
			goto exit;
		}
	}

	dev = alloc_cc770dev(0);
	if (!dev) {
		err = -ENOMEM;
		goto exit_unmap;
	}
	priv = netdev_priv(dev);

	dev->irq = irq[idx];
	priv->irq_flags = IRQF_SHARED;
	if (mem[idx]) {
		priv->reg_base = base;
		dev->base_addr = mem[idx];
		priv->read_reg = cc770_isa_mem_read_reg;
		priv->write_reg = cc770_isa_mem_write_reg;
	} else {
		priv->reg_base = (void __iomem *)port[idx];
		dev->base_addr = port[idx];

		if (iosize == CC770_IOSIZE_INDIRECT) {
			priv->read_reg = cc770_isa_port_read_reg_indirect;
			priv->write_reg = cc770_isa_port_write_reg_indirect;
		} else {
			priv->read_reg = cc770_isa_port_read_reg;
			priv->write_reg = cc770_isa_port_write_reg;
		}
	}

	if (clk[idx])
		clktmp = clk[idx];
	else if (clk[0])
		clktmp = clk[0];
	else
		clktmp = CLK_DEFAULT;
	priv->can.clock.freq = clktmp;

	if (cir[idx] != 0xff) {
		priv->cpu_interface = cir[idx];
	} else if (cir[0] != 0xff) {
		priv->cpu_interface = cir[0];
	} else {
		/* The system clock may not exceed 10 MHz */
		if (clktmp > 10000000) {
			priv->cpu_interface |= CPUIF_DSC;
			clktmp /= 2;
		}
		/* The memory clock may not exceed 8 MHz */
		if (clktmp > 8000000)
			priv->cpu_interface |= CPUIF_DMC;
	}

	if (priv->cpu_interface & CPUIF_DSC)
		priv->can.clock.freq /= 2;

	if (bcr[idx] != 0xff)
		priv->bus_config = bcr[idx];
	else if (bcr[0] != 0xff)
		priv->bus_config = bcr[0];
	else
		priv->bus_config = BCR_DEFAULT;

	if (cor[idx] != 0xff)
		priv->clkout = cor[idx];
	else if (cor[0] != 0xff)
		priv->clkout = cor[0];
	else
		priv->clkout = COR_DEFAULT;

	platform_set_drvdata(pdev, dev);
	SET_NETDEV_DEV(dev, &pdev->dev);

	err = register_cc770dev(dev);
	if (err) {
		dev_err(&pdev->dev,
			"couldn't register device (err=%d)\n", err);
		goto exit_unmap;
	}

	dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
		 priv->reg_base, dev->irq);
	return 0;

 exit_unmap:
	if (mem[idx])
		iounmap(base);
 exit_release:
	if (mem[idx])
		release_mem_region(mem[idx], iosize);
	else
		release_region(port[idx], iosize);
 exit:
	return err;
}

static int cc770_isa_remove(struct platform_device *pdev)
{
	struct net_device *dev = platform_get_drvdata(pdev);
	struct cc770_priv *priv = netdev_priv(dev);
	int idx = pdev->id;

	unregister_cc770dev(dev);

	if (mem[idx]) {
		iounmap(priv->reg_base);
		release_mem_region(mem[idx], CC770_IOSIZE);
	} else {
		if (priv->read_reg == cc770_isa_port_read_reg_indirect)
			release_region(port[idx], CC770_IOSIZE_INDIRECT);
		else
			release_region(port[idx], CC770_IOSIZE);
	}
	free_cc770dev(dev);

	return 0;
}

static struct platform_driver cc770_isa_driver = {
	.probe = cc770_isa_probe,
	.remove = cc770_isa_remove,
	.driver = {
		.name = KBUILD_MODNAME,
	},
};

static int __init cc770_isa_init(void)
{
	int idx, err;

	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
		if ((port[idx] || mem[idx]) && irq[idx]) {
			cc770_isa_devs[idx] =
				platform_device_alloc(KBUILD_MODNAME, idx);
			if (!cc770_isa_devs[idx]) {
				err = -ENOMEM;
				goto exit_free_devices;
			}
			err = platform_device_add(cc770_isa_devs[idx]);
			if (err) {
				platform_device_put(cc770_isa_devs[idx]);
				goto exit_free_devices;
			}
			pr_debug("platform device %d: port=%#lx, mem=%#lx, "
				 "irq=%d\n",
				 idx, port[idx], mem[idx], irq[idx]);
		} else if (idx == 0 || port[idx] || mem[idx]) {
			pr_err("insufficient parameters supplied\n");
			err = -EINVAL;
			goto exit_free_devices;
		}
	}

	err = platform_driver_register(&cc770_isa_driver);
	if (err)
		goto exit_free_devices;

	pr_info("driver for max. %d devices registered\n", MAXDEV);

	return 0;

exit_free_devices:
	while (--idx >= 0) {
		if (cc770_isa_devs[idx])
			platform_device_unregister(cc770_isa_devs[idx]);
	}

	return err;
}
module_init(cc770_isa_init);

static void __exit cc770_isa_exit(void)
{
	int idx;

	platform_driver_unregister(&cc770_isa_driver);
	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
		if (cc770_isa_devs[idx])
			platform_device_unregister(cc770_isa_devs[idx]);
	}
}
module_exit(cc770_isa_exit);