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
60MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
61MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
62MODULE_LICENSE("GPL v2");
63
64#define CLK_DEFAULT	16000000	/* 16 MHz */
65#define COR_DEFAULT	0x00
66#define BCR_DEFAULT	BUSCFG_CBY
67
68static unsigned long port[MAXDEV];
69static unsigned long mem[MAXDEV];
70static int irq[MAXDEV];
71static int clk[MAXDEV];
72static u8 cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
73static u8 cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
74static u8 bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
75static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
76
77module_param_hw_array(port, ulong, ioport, NULL, 0444);
78MODULE_PARM_DESC(port, "I/O port number");
79
80module_param_hw_array(mem, ulong, iomem, NULL, 0444);
81MODULE_PARM_DESC(mem, "I/O memory address");
82
83module_param_hw_array(indirect, int, ioport, NULL, 0444);
84MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
85
86module_param_hw_array(irq, int, irq, NULL, 0444);
87MODULE_PARM_DESC(irq, "IRQ number");
88
89module_param_array(clk, int, NULL, 0444);
90MODULE_PARM_DESC(clk, "External oscillator clock frequency "
91		 "(default=16000000 [16 MHz])");
92
93module_param_array(cir, byte, NULL, 0444);
94MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
95
96module_param_array(cor, byte, NULL, 0444);
97MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
98
99module_param_array(bcr, byte, NULL, 0444);
100MODULE_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 */
108static DEFINE_SPINLOCK(cc770_isa_port_lock);
109
110static struct platform_device *cc770_isa_devs[MAXDEV];
111
112static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
113{
114	return readb(priv->reg_base + reg);
115}
116
117static 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
123static 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
128static 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
134static 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
149static 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
161static 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
274exit_free:
275	free_cc770dev(dev);
276exit_unmap:
277	if (mem[idx])
278		iounmap(base);
279exit_release:
280	if (mem[idx])
281		release_mem_region(mem[idx], iosize);
282	else
283		release_region(port[idx], iosize);
284exit:
285	return err;
286}
287
288static 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
308static 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
316static 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
351exit_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}
359module_init(cc770_isa_init);
360
361static 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}
371module_exit(cc770_isa_exit);
372