1 /*
2  * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the version 2 of the GNU General Public License
6  * as published by the Free Software Foundation
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/interrupt.h>
21 #include <linux/netdevice.h>
22 #include <linux/delay.h>
23 #include <linux/irq.h>
24 #include <linux/io.h>
25 #include <linux/can/dev.h>
26 #include <linux/can/platform/sja1000.h>
27 
28 #include "sja1000.h"
29 
30 #define DRV_NAME "sja1000_isa"
31 
32 #define MAXDEV 8
33 
34 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
35 MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the ISA bus");
36 MODULE_LICENSE("GPL v2");
37 
38 #define CLK_DEFAULT	16000000	/* 16 MHz */
39 #define CDR_DEFAULT	(CDR_CBP | CDR_CLK_OFF)
40 #define OCR_DEFAULT	OCR_TX0_PUSHPULL
41 
42 static unsigned long port[MAXDEV];
43 static unsigned long mem[MAXDEV];
44 static int irq[MAXDEV];
45 static int clk[MAXDEV];
46 static unsigned char cdr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
47 static unsigned char ocr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
48 static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
49 
50 module_param_array(port, ulong, NULL, S_IRUGO);
51 MODULE_PARM_DESC(port, "I/O port number");
52 
53 module_param_array(mem, ulong, NULL, S_IRUGO);
54 MODULE_PARM_DESC(mem, "I/O memory address");
55 
56 module_param_array(indirect, int, NULL, S_IRUGO);
57 MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
58 
59 module_param_array(irq, int, NULL, S_IRUGO);
60 MODULE_PARM_DESC(irq, "IRQ number");
61 
62 module_param_array(clk, int, NULL, S_IRUGO);
63 MODULE_PARM_DESC(clk, "External oscillator clock frequency "
64 		 "(default=16000000 [16 MHz])");
65 
66 module_param_array(cdr, byte, NULL, S_IRUGO);
67 MODULE_PARM_DESC(cdr, "Clock divider register "
68 		 "(default=0x48 [CDR_CBP | CDR_CLK_OFF])");
69 
70 module_param_array(ocr, byte, NULL, S_IRUGO);
71 MODULE_PARM_DESC(ocr, "Output control register "
72 		 "(default=0x18 [OCR_TX0_PUSHPULL])");
73 
74 #define SJA1000_IOSIZE          0x20
75 #define SJA1000_IOSIZE_INDIRECT 0x02
76 
77 static struct platform_device *sja1000_isa_devs[MAXDEV];
78 
79 static u8 sja1000_isa_mem_read_reg(const struct sja1000_priv *priv, int reg)
80 {
81 	return readb(priv->reg_base + reg);
82 }
83 
84 static void sja1000_isa_mem_write_reg(const struct sja1000_priv *priv,
85 				      int reg, u8 val)
86 {
87 	writeb(val, priv->reg_base + reg);
88 }
89 
90 static u8 sja1000_isa_port_read_reg(const struct sja1000_priv *priv, int reg)
91 {
92 	return inb((unsigned long)priv->reg_base + reg);
93 }
94 
95 static void sja1000_isa_port_write_reg(const struct sja1000_priv *priv,
96 				       int reg, u8 val)
97 {
98 	outb(val, (unsigned long)priv->reg_base + reg);
99 }
100 
101 static u8 sja1000_isa_port_read_reg_indirect(const struct sja1000_priv *priv,
102 					     int reg)
103 {
104 	unsigned long base = (unsigned long)priv->reg_base;
105 
106 	outb(reg, base);
107 	return inb(base + 1);
108 }
109 
110 static void sja1000_isa_port_write_reg_indirect(const struct sja1000_priv *priv,
111 						int reg, u8 val)
112 {
113 	unsigned long base = (unsigned long)priv->reg_base;
114 
115 	outb(reg, base);
116 	outb(val, base + 1);
117 }
118 
119 static int sja1000_isa_probe(struct platform_device *pdev)
120 {
121 	struct net_device *dev;
122 	struct sja1000_priv *priv;
123 	void __iomem *base = NULL;
124 	int iosize = SJA1000_IOSIZE;
125 	int idx = pdev->id;
126 	int err;
127 
128 	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
129 		idx, port[idx], mem[idx], irq[idx]);
130 
131 	if (mem[idx]) {
132 		if (!request_mem_region(mem[idx], iosize, DRV_NAME)) {
133 			err = -EBUSY;
134 			goto exit;
135 		}
136 		base = ioremap_nocache(mem[idx], iosize);
137 		if (!base) {
138 			err = -ENOMEM;
139 			goto exit_release;
140 		}
141 	} else {
142 		if (indirect[idx] > 0 ||
143 		    (indirect[idx] == -1 && indirect[0] > 0))
144 			iosize = SJA1000_IOSIZE_INDIRECT;
145 		if (!request_region(port[idx], iosize, DRV_NAME)) {
146 			err = -EBUSY;
147 			goto exit;
148 		}
149 	}
150 
151 	dev = alloc_sja1000dev(0);
152 	if (!dev) {
153 		err = -ENOMEM;
154 		goto exit_unmap;
155 	}
156 	priv = netdev_priv(dev);
157 
158 	dev->irq = irq[idx];
159 	priv->irq_flags = IRQF_SHARED;
160 	if (mem[idx]) {
161 		priv->reg_base = base;
162 		dev->base_addr = mem[idx];
163 		priv->read_reg = sja1000_isa_mem_read_reg;
164 		priv->write_reg = sja1000_isa_mem_write_reg;
165 	} else {
166 		priv->reg_base = (void __iomem *)port[idx];
167 		dev->base_addr = port[idx];
168 
169 		if (iosize == SJA1000_IOSIZE_INDIRECT) {
170 			priv->read_reg = sja1000_isa_port_read_reg_indirect;
171 			priv->write_reg = sja1000_isa_port_write_reg_indirect;
172 		} else {
173 			priv->read_reg = sja1000_isa_port_read_reg;
174 			priv->write_reg = sja1000_isa_port_write_reg;
175 		}
176 	}
177 
178 	if (clk[idx])
179 		priv->can.clock.freq = clk[idx] / 2;
180 	else if (clk[0])
181 		priv->can.clock.freq = clk[0] / 2;
182 	else
183 		priv->can.clock.freq = CLK_DEFAULT / 2;
184 
185 	if (ocr[idx] != 0xff)
186 		priv->ocr = ocr[idx];
187 	else if (ocr[0] != 0xff)
188 		priv->ocr = ocr[0];
189 	else
190 		priv->ocr = OCR_DEFAULT;
191 
192 	if (cdr[idx] != 0xff)
193 		priv->cdr = cdr[idx];
194 	else if (cdr[0] != 0xff)
195 		priv->cdr = cdr[0];
196 	else
197 		priv->cdr = CDR_DEFAULT;
198 
199 	platform_set_drvdata(pdev, dev);
200 	SET_NETDEV_DEV(dev, &pdev->dev);
201 
202 	err = register_sja1000dev(dev);
203 	if (err) {
204 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
205 			DRV_NAME, err);
206 		goto exit_unmap;
207 	}
208 
209 	dev_info(&pdev->dev, "%s device registered (reg_base=0x%p, irq=%d)\n",
210 		 DRV_NAME, priv->reg_base, dev->irq);
211 	return 0;
212 
213  exit_unmap:
214 	if (mem[idx])
215 		iounmap(base);
216  exit_release:
217 	if (mem[idx])
218 		release_mem_region(mem[idx], iosize);
219 	else
220 		release_region(port[idx], iosize);
221  exit:
222 	return err;
223 }
224 
225 static int sja1000_isa_remove(struct platform_device *pdev)
226 {
227 	struct net_device *dev = platform_get_drvdata(pdev);
228 	struct sja1000_priv *priv = netdev_priv(dev);
229 	int idx = pdev->id;
230 
231 	unregister_sja1000dev(dev);
232 
233 	if (mem[idx]) {
234 		iounmap(priv->reg_base);
235 		release_mem_region(mem[idx], SJA1000_IOSIZE);
236 	} else {
237 		if (priv->read_reg == sja1000_isa_port_read_reg_indirect)
238 			release_region(port[idx], SJA1000_IOSIZE_INDIRECT);
239 		else
240 			release_region(port[idx], SJA1000_IOSIZE);
241 	}
242 	free_sja1000dev(dev);
243 
244 	return 0;
245 }
246 
247 static struct platform_driver sja1000_isa_driver = {
248 	.probe = sja1000_isa_probe,
249 	.remove = sja1000_isa_remove,
250 	.driver = {
251 		.name = DRV_NAME,
252 		.owner = THIS_MODULE,
253 	},
254 };
255 
256 static int __init sja1000_isa_init(void)
257 {
258 	int idx, err;
259 
260 	for (idx = 0; idx < MAXDEV; idx++) {
261 		if ((port[idx] || mem[idx]) && irq[idx]) {
262 			sja1000_isa_devs[idx] =
263 				platform_device_alloc(DRV_NAME, idx);
264 			if (!sja1000_isa_devs[idx]) {
265 				err = -ENOMEM;
266 				goto exit_free_devices;
267 			}
268 			err = platform_device_add(sja1000_isa_devs[idx]);
269 			if (err) {
270 				platform_device_put(sja1000_isa_devs[idx]);
271 				goto exit_free_devices;
272 			}
273 			pr_debug("%s: platform device %d: port=%#lx, mem=%#lx, "
274 				 "irq=%d\n",
275 				 DRV_NAME, idx, port[idx], mem[idx], irq[idx]);
276 		} else if (idx == 0 || port[idx] || mem[idx]) {
277 				pr_err("%s: insufficient parameters supplied\n",
278 				       DRV_NAME);
279 				err = -EINVAL;
280 				goto exit_free_devices;
281 		}
282 	}
283 
284 	err = platform_driver_register(&sja1000_isa_driver);
285 	if (err)
286 		goto exit_free_devices;
287 
288 	pr_info("Legacy %s driver for max. %d devices registered\n",
289 		DRV_NAME, MAXDEV);
290 
291 	return 0;
292 
293 exit_free_devices:
294 	while (--idx >= 0) {
295 		if (sja1000_isa_devs[idx])
296 			platform_device_unregister(sja1000_isa_devs[idx]);
297 	}
298 
299 	return err;
300 }
301 
302 static void __exit sja1000_isa_exit(void)
303 {
304 	int idx;
305 
306 	platform_driver_unregister(&sja1000_isa_driver);
307 	for (idx = 0; idx < MAXDEV; idx++) {
308 		if (sja1000_isa_devs[idx])
309 			platform_device_unregister(sja1000_isa_devs[idx]);
310 	}
311 }
312 
313 module_init(sja1000_isa_init);
314 module_exit(sja1000_isa_exit);
315