cc770_isa.c revision 3c8ac0f2ad53a96ac58efe7c98fac2986d081dfc 
1/*
2 * Driver for CC770 and AN82527 CAN controllers on the legacy ISA bus
3 *
4 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the version 2 of the GNU General Public License
8 * as published by the Free Software Foundation
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16/*
17 * Bosch CC770 and Intel AN82527 CAN controllers on the ISA or PC-104 bus.
18 * The I/O port or memory address and the IRQ number must be specified via
19 * module parameters:
20 *
21 *   insmod cc770_isa.ko port=0x310,0x380 irq=7,11
22 *
23 * for ISA devices using I/O ports or:
24 *
25 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11
26 *
27 * for memory mapped ISA devices.
28 *
29 * Indirect access via address and data port is supported as well:
30 *
31 *   insmod cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11
32 *
33 * Furthermore, the following mode parameter can be defined:
34 *
35 *   clk: External oscillator clock frequency (default=16000000 [16 MHz])
36 *   cir: CPU interface register (default=0x40 [DSC])
37 *   bcr: Bus configuration register (default=0x40 [CBY])
38 *   cor: Clockout register (default=0x00)
39 *
40 * Note: for clk, cir, bcr and cor, the first argument re-defines the
41 * default for all other devices, e.g.:
42 *
43 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000
44 *
45 * is equivalent to
46 *
47 *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
48 */
49
50#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
51
52#include <linux/kernel.h>
53#include <linux/module.h>
54#include <linux/platform_device.h>
55#include <linux/interrupt.h>
56#include <linux/netdevice.h>
57#include <linux/delay.h>
58#include <linux/irq.h>
59#include <linux/io.h>
60#include <linux/can.h>
61#include <linux/can/dev.h>
62#include <linux/can/platform/cc770.h>
63
64#include "cc770.h"
65
66#define MAXDEV 8
67
68MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
69MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
70MODULE_LICENSE("GPL v2");
71
72#define CLK_DEFAULT	16000000	/* 16 MHz */
73#define COR_DEFAULT	0x00
74#define BCR_DEFAULT	BUSCFG_CBY
75
76static unsigned long port[MAXDEV];
77static unsigned long mem[MAXDEV];
78static int irq[MAXDEV];
79static int clk[MAXDEV];
80static u8 cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
81static u8 cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
82static u8 bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
83static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
84
85module_param_array(port, ulong, NULL, S_IRUGO);
86MODULE_PARM_DESC(port, "I/O port number");
87
88module_param_array(mem, ulong, NULL, S_IRUGO);
89MODULE_PARM_DESC(mem, "I/O memory address");
90
91module_param_array(indirect, int, NULL, S_IRUGO);
92MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
93
94module_param_array(irq, int, NULL, S_IRUGO);
95MODULE_PARM_DESC(irq, "IRQ number");
96
97module_param_array(clk, int, NULL, S_IRUGO);
98MODULE_PARM_DESC(clk, "External oscillator clock frequency "
99		 "(default=16000000 [16 MHz])");
100
101module_param_array(cir, byte, NULL, S_IRUGO);
102MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
103
104module_param_array(cor, byte, NULL, S_IRUGO);
105MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
106
107module_param_array(bcr, byte, NULL, S_IRUGO);
108MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
109
110#define CC770_IOSIZE          0x20
111#define CC770_IOSIZE_INDIRECT 0x02
112
113/* Spinlock for cc770_isa_port_write_reg_indirect
114 * and cc770_isa_port_read_reg_indirect
115 */
116static DEFINE_SPINLOCK(cc770_isa_port_lock);
117
118static struct platform_device *cc770_isa_devs[MAXDEV];
119
120static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
121{
122	return readb(priv->reg_base + reg);
123}
124
125static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
126				      int reg, u8 val)
127{
128	writeb(val, priv->reg_base + reg);
129}
130
131static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
132{
133	return inb((unsigned long)priv->reg_base + reg);
134}
135
136static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
137				       int reg, u8 val)
138{
139	outb(val, (unsigned long)priv->reg_base + reg);
140}
141
142static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
143					     int reg)
144{
145	unsigned long base = (unsigned long)priv->reg_base;
146	unsigned long flags;
147	u8 val;
148
149	spin_lock_irqsave(&cc770_isa_port_lock, flags);
150	outb(reg, base);
151	val = inb(base + 1);
152	spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
153
154	return val;
155}
156
157static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
158						int reg, u8 val)
159{
160	unsigned long base = (unsigned long)priv->reg_base;
161	unsigned long flags;
162
163	spin_lock_irqsave(&cc770_isa_port_lock, flags);
164	outb(reg, base);
165	outb(val, base + 1);
166	spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
167}
168
169static int cc770_isa_probe(struct platform_device *pdev)
170{
171	struct net_device *dev;
172	struct cc770_priv *priv;
173	void __iomem *base = NULL;
174	int iosize = CC770_IOSIZE;
175	int idx = pdev->id;
176	int err;
177	u32 clktmp;
178
179	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
180		idx, port[idx], mem[idx], irq[idx]);
181	if (mem[idx]) {
182		if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
183			err = -EBUSY;
184			goto exit;
185		}
186		base = ioremap_nocache(mem[idx], iosize);
187		if (!base) {
188			err = -ENOMEM;
189			goto exit_release;
190		}
191	} else {
192		if (indirect[idx] > 0 ||
193		    (indirect[idx] == -1 && indirect[0] > 0))
194			iosize = CC770_IOSIZE_INDIRECT;
195		if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
196			err = -EBUSY;
197			goto exit;
198		}
199	}
200
201	dev = alloc_cc770dev(0);
202	if (!dev) {
203		err = -ENOMEM;
204		goto exit_unmap;
205	}
206	priv = netdev_priv(dev);
207
208	dev->irq = irq[idx];
209	priv->irq_flags = IRQF_SHARED;
210	if (mem[idx]) {
211		priv->reg_base = base;
212		dev->base_addr = mem[idx];
213		priv->read_reg = cc770_isa_mem_read_reg;
214		priv->write_reg = cc770_isa_mem_write_reg;
215	} else {
216		priv->reg_base = (void __iomem *)port[idx];
217		dev->base_addr = port[idx];
218
219		if (iosize == CC770_IOSIZE_INDIRECT) {
220			priv->read_reg = cc770_isa_port_read_reg_indirect;
221			priv->write_reg = cc770_isa_port_write_reg_indirect;
222		} else {
223			priv->read_reg = cc770_isa_port_read_reg;
224			priv->write_reg = cc770_isa_port_write_reg;
225		}
226	}
227
228	if (clk[idx])
229		clktmp = clk[idx];
230	else if (clk[0])
231		clktmp = clk[0];
232	else
233		clktmp = CLK_DEFAULT;
234	priv->can.clock.freq = clktmp;
235
236	if (cir[idx] != 0xff) {
237		priv->cpu_interface = cir[idx];
238	} else if (cir[0] != 0xff) {
239		priv->cpu_interface = cir[0];
240	} else {
241		/* The system clock may not exceed 10 MHz */
242		if (clktmp > 10000000) {
243			priv->cpu_interface |= CPUIF_DSC;
244			clktmp /= 2;
245		}
246		/* The memory clock may not exceed 8 MHz */
247		if (clktmp > 8000000)
248			priv->cpu_interface |= CPUIF_DMC;
249	}
250
251	if (priv->cpu_interface & CPUIF_DSC)
252		priv->can.clock.freq /= 2;
253
254	if (bcr[idx] != 0xff)
255		priv->bus_config = bcr[idx];
256	else if (bcr[0] != 0xff)
257		priv->bus_config = bcr[0];
258	else
259		priv->bus_config = BCR_DEFAULT;
260
261	if (cor[idx] != 0xff)
262		priv->clkout = cor[idx];
263	else if (cor[0] != 0xff)
264		priv->clkout = cor[0];
265	else
266		priv->clkout = COR_DEFAULT;
267
268	dev_set_drvdata(&pdev->dev, dev);
269	SET_NETDEV_DEV(dev, &pdev->dev);
270
271	err = register_cc770dev(dev);
272	if (err) {
273		dev_err(&pdev->dev,
274			"couldn't register device (err=%d)\n", err);
275		goto exit_unmap;
276	}
277
278	dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
279		 priv->reg_base, dev->irq);
280	return 0;
281
282 exit_unmap:
283	if (mem[idx])
284		iounmap(base);
285 exit_release:
286	if (mem[idx])
287		release_mem_region(mem[idx], iosize);
288	else
289		release_region(port[idx], iosize);
290 exit:
291	return err;
292}
293
294static int cc770_isa_remove(struct platform_device *pdev)
295{
296	struct net_device *dev = dev_get_drvdata(&pdev->dev);
297	struct cc770_priv *priv = netdev_priv(dev);
298	int idx = pdev->id;
299
300	unregister_cc770dev(dev);
301	dev_set_drvdata(&pdev->dev, NULL);
302
303	if (mem[idx]) {
304		iounmap(priv->reg_base);
305		release_mem_region(mem[idx], CC770_IOSIZE);
306	} else {
307		if (priv->read_reg == cc770_isa_port_read_reg_indirect)
308			release_region(port[idx], CC770_IOSIZE_INDIRECT);
309		else
310			release_region(port[idx], CC770_IOSIZE);
311	}
312	free_cc770dev(dev);
313
314	return 0;
315}
316
317static struct platform_driver cc770_isa_driver = {
318	.probe = cc770_isa_probe,
319	.remove = cc770_isa_remove,
320	.driver = {
321		.name = KBUILD_MODNAME,
322		.owner = THIS_MODULE,
323	},
324};
325
326static int __init cc770_isa_init(void)
327{
328	int idx, err;
329
330	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
331		if ((port[idx] || mem[idx]) && irq[idx]) {
332			cc770_isa_devs[idx] =
333				platform_device_alloc(KBUILD_MODNAME, idx);
334			if (!cc770_isa_devs[idx]) {
335				err = -ENOMEM;
336				goto exit_free_devices;
337			}
338			err = platform_device_add(cc770_isa_devs[idx]);
339			if (err) {
340				platform_device_put(cc770_isa_devs[idx]);
341				goto exit_free_devices;
342			}
343			pr_debug("platform device %d: port=%#lx, mem=%#lx, "
344				 "irq=%d\n",
345				 idx, port[idx], mem[idx], irq[idx]);
346		} else if (idx == 0 || port[idx] || mem[idx]) {
347			pr_err("insufficient parameters supplied\n");
348			err = -EINVAL;
349			goto exit_free_devices;
350		}
351	}
352
353	err = platform_driver_register(&cc770_isa_driver);
354	if (err)
355		goto exit_free_devices;
356
357	pr_info("driver for max. %d devices registered\n", MAXDEV);
358
359	return 0;
360
361exit_free_devices:
362	while (--idx >= 0) {
363		if (cc770_isa_devs[idx])
364			platform_device_unregister(cc770_isa_devs[idx]);
365	}
366
367	return err;
368}
369module_init(cc770_isa_init);
370
371static void __exit cc770_isa_exit(void)
372{
373	int idx;
374
375	platform_driver_unregister(&cc770_isa_driver);
376	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
377		if (cc770_isa_devs[idx])
378			platform_device_unregister(cc770_isa_devs[idx]);
379	}
380}
381module_exit(cc770_isa_exit);
382