xref: /openbmc/linux/drivers/net/can/cc770/cc770_isa.c (revision 93810076)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for CC770 and AN82527 CAN controllers on the legacy ISA bus
4  *
5  * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
6  */
7 
8 /*
9  * Bosch CC770 and Intel AN82527 CAN controllers on the ISA or PC-104 bus.
10  * The I/O port or memory address and the IRQ number must be specified via
11  * module parameters:
12  *
13  *   insmod cc770_isa.ko port=0x310,0x380 irq=7,11
14  *
15  * for ISA devices using I/O ports or:
16  *
17  *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11
18  *
19  * for memory mapped ISA devices.
20  *
21  * Indirect access via address and data port is supported as well:
22  *
23  *   insmod cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11
24  *
25  * Furthermore, the following mode parameter can be defined:
26  *
27  *   clk: External oscillator clock frequency (default=16000000 [16 MHz])
28  *   cir: CPU interface register (default=0x40 [DSC])
29  *   bcr: Bus configuration register (default=0x40 [CBY])
30  *   cor: Clockout register (default=0x00)
31  *
32  * Note: for clk, cir, bcr and cor, the first argument re-defines the
33  * default for all other devices, e.g.:
34  *
35  *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000
36  *
37  * is equivalent to
38  *
39  *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
40  */
41 
42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
43 
44 #include <linux/kernel.h>
45 #include <linux/module.h>
46 #include <linux/platform_device.h>
47 #include <linux/interrupt.h>
48 #include <linux/netdevice.h>
49 #include <linux/delay.h>
50 #include <linux/irq.h>
51 #include <linux/io.h>
52 #include <linux/can.h>
53 #include <linux/can/dev.h>
54 #include <linux/can/platform/cc770.h>
55 
56 #include "cc770.h"
57 
58 #define MAXDEV 8
59 
60 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
61 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
62 MODULE_LICENSE("GPL v2");
63 
64 #define CLK_DEFAULT	16000000	/* 16 MHz */
65 #define COR_DEFAULT	0x00
66 #define BCR_DEFAULT	BUSCFG_CBY
67 
68 static unsigned long port[MAXDEV];
69 static unsigned long mem[MAXDEV];
70 static int irq[MAXDEV];
71 static int clk[MAXDEV];
72 static u8 cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
73 static u8 cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
74 static u8 bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
75 static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
76 
77 module_param_hw_array(port, ulong, ioport, NULL, 0444);
78 MODULE_PARM_DESC(port, "I/O port number");
79 
80 module_param_hw_array(mem, ulong, iomem, NULL, 0444);
81 MODULE_PARM_DESC(mem, "I/O memory address");
82 
83 module_param_hw_array(indirect, int, ioport, NULL, 0444);
84 MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
85 
86 module_param_hw_array(irq, int, irq, NULL, 0444);
87 MODULE_PARM_DESC(irq, "IRQ number");
88 
89 module_param_array(clk, int, NULL, 0444);
90 MODULE_PARM_DESC(clk, "External oscillator clock frequency "
91 		 "(default=16000000 [16 MHz])");
92 
93 module_param_array(cir, byte, NULL, 0444);
94 MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
95 
96 module_param_array(cor, byte, NULL, 0444);
97 MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
98 
99 module_param_array(bcr, byte, NULL, 0444);
100 MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
101 
102 #define CC770_IOSIZE          0x20
103 #define CC770_IOSIZE_INDIRECT 0x02
104 
105 /* Spinlock for cc770_isa_port_write_reg_indirect
106  * and cc770_isa_port_read_reg_indirect
107  */
108 static DEFINE_SPINLOCK(cc770_isa_port_lock);
109 
110 static struct platform_device *cc770_isa_devs[MAXDEV];
111 
cc770_isa_mem_read_reg(const struct cc770_priv * priv,int reg)112 static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
113 {
114 	return readb(priv->reg_base + reg);
115 }
116 
cc770_isa_mem_write_reg(const struct cc770_priv * priv,int reg,u8 val)117 static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
118 				      int reg, u8 val)
119 {
120 	writeb(val, priv->reg_base + reg);
121 }
122 
cc770_isa_port_read_reg(const struct cc770_priv * priv,int reg)123 static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
124 {
125 	return inb((unsigned long)priv->reg_base + reg);
126 }
127 
cc770_isa_port_write_reg(const struct cc770_priv * priv,int reg,u8 val)128 static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
129 				       int reg, u8 val)
130 {
131 	outb(val, (unsigned long)priv->reg_base + reg);
132 }
133 
cc770_isa_port_read_reg_indirect(const struct cc770_priv * priv,int reg)134 static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
135 					     int reg)
136 {
137 	unsigned long base = (unsigned long)priv->reg_base;
138 	unsigned long flags;
139 	u8 val;
140 
141 	spin_lock_irqsave(&cc770_isa_port_lock, flags);
142 	outb(reg, base);
143 	val = inb(base + 1);
144 	spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
145 
146 	return val;
147 }
148 
cc770_isa_port_write_reg_indirect(const struct cc770_priv * priv,int reg,u8 val)149 static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
150 						int reg, u8 val)
151 {
152 	unsigned long base = (unsigned long)priv->reg_base;
153 	unsigned long flags;
154 
155 	spin_lock_irqsave(&cc770_isa_port_lock, flags);
156 	outb(reg, base);
157 	outb(val, base + 1);
158 	spin_unlock_irqrestore(&cc770_isa_port_lock, flags);
159 }
160 
cc770_isa_probe(struct platform_device * pdev)161 static int cc770_isa_probe(struct platform_device *pdev)
162 {
163 	struct net_device *dev;
164 	struct cc770_priv *priv;
165 	void __iomem *base = NULL;
166 	int iosize = CC770_IOSIZE;
167 	int idx = pdev->id;
168 	int err;
169 	u32 clktmp;
170 
171 	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
172 		idx, port[idx], mem[idx], irq[idx]);
173 	if (mem[idx]) {
174 		if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
175 			err = -EBUSY;
176 			goto exit;
177 		}
178 		base = ioremap(mem[idx], iosize);
179 		if (!base) {
180 			err = -ENOMEM;
181 			goto exit_release;
182 		}
183 	} else {
184 		if (indirect[idx] > 0 ||
185 		    (indirect[idx] == -1 && indirect[0] > 0))
186 			iosize = CC770_IOSIZE_INDIRECT;
187 		if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
188 			err = -EBUSY;
189 			goto exit;
190 		}
191 	}
192 
193 	dev = alloc_cc770dev(0);
194 	if (!dev) {
195 		err = -ENOMEM;
196 		goto exit_unmap;
197 	}
198 	priv = netdev_priv(dev);
199 
200 	dev->irq = irq[idx];
201 	priv->irq_flags = IRQF_SHARED;
202 	if (mem[idx]) {
203 		priv->reg_base = base;
204 		dev->base_addr = mem[idx];
205 		priv->read_reg = cc770_isa_mem_read_reg;
206 		priv->write_reg = cc770_isa_mem_write_reg;
207 	} else {
208 		priv->reg_base = (void __iomem *)port[idx];
209 		dev->base_addr = port[idx];
210 
211 		if (iosize == CC770_IOSIZE_INDIRECT) {
212 			priv->read_reg = cc770_isa_port_read_reg_indirect;
213 			priv->write_reg = cc770_isa_port_write_reg_indirect;
214 		} else {
215 			priv->read_reg = cc770_isa_port_read_reg;
216 			priv->write_reg = cc770_isa_port_write_reg;
217 		}
218 	}
219 
220 	if (clk[idx])
221 		clktmp = clk[idx];
222 	else if (clk[0])
223 		clktmp = clk[0];
224 	else
225 		clktmp = CLK_DEFAULT;
226 	priv->can.clock.freq = clktmp;
227 
228 	if (cir[idx] != 0xff) {
229 		priv->cpu_interface = cir[idx];
230 	} else if (cir[0] != 0xff) {
231 		priv->cpu_interface = cir[0];
232 	} else {
233 		/* The system clock may not exceed 10 MHz */
234 		if (clktmp > 10000000) {
235 			priv->cpu_interface |= CPUIF_DSC;
236 			clktmp /= 2;
237 		}
238 		/* The memory clock may not exceed 8 MHz */
239 		if (clktmp > 8000000)
240 			priv->cpu_interface |= CPUIF_DMC;
241 	}
242 
243 	if (priv->cpu_interface & CPUIF_DSC)
244 		priv->can.clock.freq /= 2;
245 
246 	if (bcr[idx] != 0xff)
247 		priv->bus_config = bcr[idx];
248 	else if (bcr[0] != 0xff)
249 		priv->bus_config = bcr[0];
250 	else
251 		priv->bus_config = BCR_DEFAULT;
252 
253 	if (cor[idx] != 0xff)
254 		priv->clkout = cor[idx];
255 	else if (cor[0] != 0xff)
256 		priv->clkout = cor[0];
257 	else
258 		priv->clkout = COR_DEFAULT;
259 
260 	platform_set_drvdata(pdev, dev);
261 	SET_NETDEV_DEV(dev, &pdev->dev);
262 
263 	err = register_cc770dev(dev);
264 	if (err) {
265 		dev_err(&pdev->dev,
266 			"couldn't register device (err=%d)\n", err);
267 		goto exit_free;
268 	}
269 
270 	dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
271 		 priv->reg_base, dev->irq);
272 	return 0;
273 
274 exit_free:
275 	free_cc770dev(dev);
276 exit_unmap:
277 	if (mem[idx])
278 		iounmap(base);
279 exit_release:
280 	if (mem[idx])
281 		release_mem_region(mem[idx], iosize);
282 	else
283 		release_region(port[idx], iosize);
284 exit:
285 	return err;
286 }
287 
cc770_isa_remove(struct platform_device * pdev)288 static void cc770_isa_remove(struct platform_device *pdev)
289 {
290 	struct net_device *dev = platform_get_drvdata(pdev);
291 	struct cc770_priv *priv = netdev_priv(dev);
292 	int idx = pdev->id;
293 
294 	unregister_cc770dev(dev);
295 
296 	if (mem[idx]) {
297 		iounmap(priv->reg_base);
298 		release_mem_region(mem[idx], CC770_IOSIZE);
299 	} else {
300 		if (priv->read_reg == cc770_isa_port_read_reg_indirect)
301 			release_region(port[idx], CC770_IOSIZE_INDIRECT);
302 		else
303 			release_region(port[idx], CC770_IOSIZE);
304 	}
305 	free_cc770dev(dev);
306 }
307 
308 static struct platform_driver cc770_isa_driver = {
309 	.probe = cc770_isa_probe,
310 	.remove_new = cc770_isa_remove,
311 	.driver = {
312 		.name = KBUILD_MODNAME,
313 	},
314 };
315 
cc770_isa_init(void)316 static int __init cc770_isa_init(void)
317 {
318 	int idx, err;
319 
320 	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
321 		if ((port[idx] || mem[idx]) && irq[idx]) {
322 			cc770_isa_devs[idx] =
323 				platform_device_alloc(KBUILD_MODNAME, idx);
324 			if (!cc770_isa_devs[idx]) {
325 				err = -ENOMEM;
326 				goto exit_free_devices;
327 			}
328 			err = platform_device_add(cc770_isa_devs[idx]);
329 			if (err) {
330 				platform_device_put(cc770_isa_devs[idx]);
331 				goto exit_free_devices;
332 			}
333 			pr_debug("platform device %d: port=%#lx, mem=%#lx, "
334 				 "irq=%d\n",
335 				 idx, port[idx], mem[idx], irq[idx]);
336 		} else if (idx == 0 || port[idx] || mem[idx]) {
337 			pr_err("insufficient parameters supplied\n");
338 			err = -EINVAL;
339 			goto exit_free_devices;
340 		}
341 	}
342 
343 	err = platform_driver_register(&cc770_isa_driver);
344 	if (err)
345 		goto exit_free_devices;
346 
347 	pr_info("driver for max. %d devices registered\n", MAXDEV);
348 
349 	return 0;
350 
351 exit_free_devices:
352 	while (--idx >= 0) {
353 		if (cc770_isa_devs[idx])
354 			platform_device_unregister(cc770_isa_devs[idx]);
355 	}
356 
357 	return err;
358 }
359 module_init(cc770_isa_init);
360 
cc770_isa_exit(void)361 static void __exit cc770_isa_exit(void)
362 {
363 	int idx;
364 
365 	platform_driver_unregister(&cc770_isa_driver);
366 	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
367 		if (cc770_isa_devs[idx])
368 			platform_device_unregister(cc770_isa_devs[idx]);
369 	}
370 }
371 module_exit(cc770_isa_exit);
372