xref: /linux/drivers/net/can/cc770/cc770_isa.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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 
68 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
69 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
70 MODULE_LICENSE("GPL v2");
71 
72 #define CLK_DEFAULT	16000000	/* 16 MHz */
73 #define COR_DEFAULT	0x00
74 #define BCR_DEFAULT	BUSCFG_CBY
75 
76 static unsigned long port[MAXDEV];
77 static unsigned long mem[MAXDEV];
78 static int __devinitdata irq[MAXDEV];
79 static int __devinitdata clk[MAXDEV];
80 static u8 __devinitdata cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
81 static u8 __devinitdata cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
82 static u8 __devinitdata bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
83 static int __devinitdata indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
84 
85 module_param_array(port, ulong, NULL, S_IRUGO);
86 MODULE_PARM_DESC(port, "I/O port number");
87 
88 module_param_array(mem, ulong, NULL, S_IRUGO);
89 MODULE_PARM_DESC(mem, "I/O memory address");
90 
91 module_param_array(indirect, int, NULL, S_IRUGO);
92 MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
93 
94 module_param_array(irq, int, NULL, S_IRUGO);
95 MODULE_PARM_DESC(irq, "IRQ number");
96 
97 module_param_array(clk, int, NULL, S_IRUGO);
98 MODULE_PARM_DESC(clk, "External oscillator clock frequency "
99 		 "(default=16000000 [16 MHz])");
100 
101 module_param_array(cir, byte, NULL, S_IRUGO);
102 MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
103 
104 module_param_array(cor, byte, NULL, S_IRUGO);
105 MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
106 
107 module_param_array(bcr, byte, NULL, S_IRUGO);
108 MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
109 
110 #define CC770_IOSIZE          0x20
111 #define CC770_IOSIZE_INDIRECT 0x02
112 
113 static struct platform_device *cc770_isa_devs[MAXDEV];
114 
115 static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
116 {
117 	return readb(priv->reg_base + reg);
118 }
119 
120 static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
121 				      int reg, u8 val)
122 {
123 	writeb(val, priv->reg_base + reg);
124 }
125 
126 static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
127 {
128 	return inb((unsigned long)priv->reg_base + reg);
129 }
130 
131 static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
132 				       int reg, u8 val)
133 {
134 	outb(val, (unsigned long)priv->reg_base + reg);
135 }
136 
137 static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
138 					     int reg)
139 {
140 	unsigned long base = (unsigned long)priv->reg_base;
141 
142 	outb(reg, base);
143 	return inb(base + 1);
144 }
145 
146 static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
147 						int reg, u8 val)
148 {
149 	unsigned long base = (unsigned long)priv->reg_base;
150 
151 	outb(reg, base);
152 	outb(val, base + 1);
153 }
154 
155 static int __devinit cc770_isa_probe(struct platform_device *pdev)
156 {
157 	struct net_device *dev;
158 	struct cc770_priv *priv;
159 	void __iomem *base = NULL;
160 	int iosize = CC770_IOSIZE;
161 	int idx = pdev->id;
162 	int err;
163 	u32 clktmp;
164 
165 	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
166 		idx, port[idx], mem[idx], irq[idx]);
167 	if (mem[idx]) {
168 		if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
169 			err = -EBUSY;
170 			goto exit;
171 		}
172 		base = ioremap_nocache(mem[idx], iosize);
173 		if (!base) {
174 			err = -ENOMEM;
175 			goto exit_release;
176 		}
177 	} else {
178 		if (indirect[idx] > 0 ||
179 		    (indirect[idx] == -1 && indirect[0] > 0))
180 			iosize = CC770_IOSIZE_INDIRECT;
181 		if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
182 			err = -EBUSY;
183 			goto exit;
184 		}
185 	}
186 
187 	dev = alloc_cc770dev(0);
188 	if (!dev) {
189 		err = -ENOMEM;
190 		goto exit_unmap;
191 	}
192 	priv = netdev_priv(dev);
193 
194 	dev->irq = irq[idx];
195 	priv->irq_flags = IRQF_SHARED;
196 	if (mem[idx]) {
197 		priv->reg_base = base;
198 		dev->base_addr = mem[idx];
199 		priv->read_reg = cc770_isa_mem_read_reg;
200 		priv->write_reg = cc770_isa_mem_write_reg;
201 	} else {
202 		priv->reg_base = (void __iomem *)port[idx];
203 		dev->base_addr = port[idx];
204 
205 		if (iosize == CC770_IOSIZE_INDIRECT) {
206 			priv->read_reg = cc770_isa_port_read_reg_indirect;
207 			priv->write_reg = cc770_isa_port_write_reg_indirect;
208 		} else {
209 			priv->read_reg = cc770_isa_port_read_reg;
210 			priv->write_reg = cc770_isa_port_write_reg;
211 		}
212 	}
213 
214 	if (clk[idx])
215 		clktmp = clk[idx];
216 	else if (clk[0])
217 		clktmp = clk[0];
218 	else
219 		clktmp = CLK_DEFAULT;
220 	priv->can.clock.freq = clktmp;
221 
222 	if (cir[idx] != 0xff) {
223 		priv->cpu_interface = cir[idx];
224 	} else if (cir[0] != 0xff) {
225 		priv->cpu_interface = cir[0];
226 	} else {
227 		/* The system clock may not exceed 10 MHz */
228 		if (clktmp > 10000000) {
229 			priv->cpu_interface |= CPUIF_DSC;
230 			clktmp /= 2;
231 		}
232 		/* The memory clock may not exceed 8 MHz */
233 		if (clktmp > 8000000)
234 			priv->cpu_interface |= CPUIF_DMC;
235 	}
236 
237 	if (priv->cpu_interface & CPUIF_DSC)
238 		priv->can.clock.freq /= 2;
239 
240 	if (bcr[idx] != 0xff)
241 		priv->bus_config = bcr[idx];
242 	else if (bcr[0] != 0xff)
243 		priv->bus_config = bcr[0];
244 	else
245 		priv->bus_config = BCR_DEFAULT;
246 
247 	if (cor[idx] != 0xff)
248 		priv->clkout = cor[idx];
249 	else if (cor[0] != 0xff)
250 		priv->clkout = cor[0];
251 	else
252 		priv->clkout = COR_DEFAULT;
253 
254 	dev_set_drvdata(&pdev->dev, dev);
255 	SET_NETDEV_DEV(dev, &pdev->dev);
256 
257 	err = register_cc770dev(dev);
258 	if (err) {
259 		dev_err(&pdev->dev,
260 			"couldn't register device (err=%d)\n", err);
261 		goto exit_unmap;
262 	}
263 
264 	dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
265 		 priv->reg_base, dev->irq);
266 	return 0;
267 
268  exit_unmap:
269 	if (mem[idx])
270 		iounmap(base);
271  exit_release:
272 	if (mem[idx])
273 		release_mem_region(mem[idx], iosize);
274 	else
275 		release_region(port[idx], iosize);
276  exit:
277 	return err;
278 }
279 
280 static int __devexit cc770_isa_remove(struct platform_device *pdev)
281 {
282 	struct net_device *dev = dev_get_drvdata(&pdev->dev);
283 	struct cc770_priv *priv = netdev_priv(dev);
284 	int idx = pdev->id;
285 
286 	unregister_cc770dev(dev);
287 	dev_set_drvdata(&pdev->dev, NULL);
288 
289 	if (mem[idx]) {
290 		iounmap(priv->reg_base);
291 		release_mem_region(mem[idx], CC770_IOSIZE);
292 	} else {
293 		if (priv->read_reg == cc770_isa_port_read_reg_indirect)
294 			release_region(port[idx], CC770_IOSIZE_INDIRECT);
295 		else
296 			release_region(port[idx], CC770_IOSIZE);
297 	}
298 	free_cc770dev(dev);
299 
300 	return 0;
301 }
302 
303 static struct platform_driver cc770_isa_driver = {
304 	.probe = cc770_isa_probe,
305 	.remove = __devexit_p(cc770_isa_remove),
306 	.driver = {
307 		.name = KBUILD_MODNAME,
308 		.owner = THIS_MODULE,
309 	},
310 };
311 
312 static int __init cc770_isa_init(void)
313 {
314 	int idx, err;
315 
316 	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
317 		if ((port[idx] || mem[idx]) && irq[idx]) {
318 			cc770_isa_devs[idx] =
319 				platform_device_alloc(KBUILD_MODNAME, idx);
320 			if (!cc770_isa_devs[idx]) {
321 				err = -ENOMEM;
322 				goto exit_free_devices;
323 			}
324 			err = platform_device_add(cc770_isa_devs[idx]);
325 			if (err) {
326 				platform_device_put(cc770_isa_devs[idx]);
327 				goto exit_free_devices;
328 			}
329 			pr_debug("platform device %d: port=%#lx, mem=%#lx, "
330 				 "irq=%d\n",
331 				 idx, port[idx], mem[idx], irq[idx]);
332 		} else if (idx == 0 || port[idx] || mem[idx]) {
333 			pr_err("insufficient parameters supplied\n");
334 			err = -EINVAL;
335 			goto exit_free_devices;
336 		}
337 	}
338 
339 	err = platform_driver_register(&cc770_isa_driver);
340 	if (err)
341 		goto exit_free_devices;
342 
343 	pr_info("driver for max. %d devices registered\n", MAXDEV);
344 
345 	return 0;
346 
347 exit_free_devices:
348 	while (--idx >= 0) {
349 		if (cc770_isa_devs[idx])
350 			platform_device_unregister(cc770_isa_devs[idx]);
351 	}
352 
353 	return err;
354 }
355 module_init(cc770_isa_init);
356 
357 static void __exit cc770_isa_exit(void)
358 {
359 	int idx;
360 
361 	platform_driver_unregister(&cc770_isa_driver);
362 	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
363 		if (cc770_isa_devs[idx])
364 			platform_device_unregister(cc770_isa_devs[idx]);
365 	}
366 }
367 module_exit(cc770_isa_exit);
368