1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
4 */
5
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/platform_device.h>
9#include <linux/interrupt.h>
10#include <linux/netdevice.h>
11#include <linux/delay.h>
12#include <linux/irq.h>
13#include <linux/io.h>
14#include <linux/can/dev.h>
15#include <linux/can/platform/sja1000.h>
16
17#include "sja1000.h"
18
19#define DRV_NAME "sja1000_isa"
20
21#define MAXDEV 8
22
23MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
24MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the ISA bus");
25MODULE_LICENSE("GPL v2");
26
27#define CLK_DEFAULT	16000000	/* 16 MHz */
28#define CDR_DEFAULT	(CDR_CBP | CDR_CLK_OFF)
29#define OCR_DEFAULT	OCR_TX0_PUSHPULL
30
31static unsigned long port[MAXDEV];
32static unsigned long mem[MAXDEV];
33static int irq[MAXDEV];
34static int clk[MAXDEV];
35static unsigned char cdr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
36static unsigned char ocr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
37static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
38static spinlock_t indirect_lock[MAXDEV];  /* lock for indirect access mode */
39
40module_param_hw_array(port, ulong, ioport, NULL, 0444);
41MODULE_PARM_DESC(port, "I/O port number");
42
43module_param_hw_array(mem, ulong, iomem, NULL, 0444);
44MODULE_PARM_DESC(mem, "I/O memory address");
45
46module_param_hw_array(indirect, int, ioport, NULL, 0444);
47MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
48
49module_param_hw_array(irq, int, irq, NULL, 0444);
50MODULE_PARM_DESC(irq, "IRQ number");
51
52module_param_array(clk, int, NULL, 0444);
53MODULE_PARM_DESC(clk, "External oscillator clock frequency "
54		 "(default=16000000 [16 MHz])");
55
56module_param_array(cdr, byte, NULL, 0444);
57MODULE_PARM_DESC(cdr, "Clock divider register "
58		 "(default=0x48 [CDR_CBP | CDR_CLK_OFF])");
59
60module_param_array(ocr, byte, NULL, 0444);
61MODULE_PARM_DESC(ocr, "Output control register "
62		 "(default=0x18 [OCR_TX0_PUSHPULL])");
63
64#define SJA1000_IOSIZE          0x20
65#define SJA1000_IOSIZE_INDIRECT 0x02
66
67static struct platform_device *sja1000_isa_devs[MAXDEV];
68
69static u8 sja1000_isa_mem_read_reg(const struct sja1000_priv *priv, int reg)
70{
71	return readb(priv->reg_base + reg);
72}
73
74static void sja1000_isa_mem_write_reg(const struct sja1000_priv *priv,
75				      int reg, u8 val)
76{
77	writeb(val, priv->reg_base + reg);
78}
79
80static u8 sja1000_isa_port_read_reg(const struct sja1000_priv *priv, int reg)
81{
82	return inb((unsigned long)priv->reg_base + reg);
83}
84
85static void sja1000_isa_port_write_reg(const struct sja1000_priv *priv,
86				       int reg, u8 val)
87{
88	outb(val, (unsigned long)priv->reg_base + reg);
89}
90
91static u8 sja1000_isa_port_read_reg_indirect(const struct sja1000_priv *priv,
92					     int reg)
93{
94	unsigned long flags, base = (unsigned long)priv->reg_base;
95	u8 readval;
96
97	spin_lock_irqsave(&indirect_lock[priv->dev->dev_id], flags);
98	outb(reg, base);
99	readval = inb(base + 1);
100	spin_unlock_irqrestore(&indirect_lock[priv->dev->dev_id], flags);
101
102	return readval;
103}
104
105static void sja1000_isa_port_write_reg_indirect(const struct sja1000_priv *priv,
106						int reg, u8 val)
107{
108	unsigned long flags, base = (unsigned long)priv->reg_base;
109
110	spin_lock_irqsave(&indirect_lock[priv->dev->dev_id], flags);
111	outb(reg, base);
112	outb(val, base + 1);
113	spin_unlock_irqrestore(&indirect_lock[priv->dev->dev_id], flags);
114}
115
116static int sja1000_isa_probe(struct platform_device *pdev)
117{
118	struct net_device *dev;
119	struct sja1000_priv *priv;
120	void __iomem *base = NULL;
121	int iosize = SJA1000_IOSIZE;
122	int idx = pdev->id;
123	int err;
124
125	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
126		idx, port[idx], mem[idx], irq[idx]);
127
128	if (mem[idx]) {
129		if (!request_mem_region(mem[idx], iosize, DRV_NAME)) {
130			err = -EBUSY;
131			goto exit;
132		}
133		base = ioremap(mem[idx], iosize);
134		if (!base) {
135			err = -ENOMEM;
136			goto exit_release;
137		}
138	} else {
139		if (indirect[idx] > 0 ||
140		    (indirect[idx] == -1 && indirect[0] > 0))
141			iosize = SJA1000_IOSIZE_INDIRECT;
142		if (!request_region(port[idx], iosize, DRV_NAME)) {
143			err = -EBUSY;
144			goto exit;
145		}
146	}
147
148	dev = alloc_sja1000dev(0);
149	if (!dev) {
150		err = -ENOMEM;
151		goto exit_unmap;
152	}
153	priv = netdev_priv(dev);
154
155	dev->irq = irq[idx];
156	priv->irq_flags = IRQF_SHARED;
157	if (mem[idx]) {
158		priv->reg_base = base;
159		dev->base_addr = mem[idx];
160		priv->read_reg = sja1000_isa_mem_read_reg;
161		priv->write_reg = sja1000_isa_mem_write_reg;
162	} else {
163		priv->reg_base = (void __iomem *)port[idx];
164		dev->base_addr = port[idx];
165
166		if (iosize == SJA1000_IOSIZE_INDIRECT) {
167			priv->read_reg = sja1000_isa_port_read_reg_indirect;
168			priv->write_reg = sja1000_isa_port_write_reg_indirect;
169			spin_lock_init(&indirect_lock[idx]);
170		} else {
171			priv->read_reg = sja1000_isa_port_read_reg;
172			priv->write_reg = sja1000_isa_port_write_reg;
173		}
174	}
175
176	if (clk[idx])
177		priv->can.clock.freq = clk[idx] / 2;
178	else if (clk[0])
179		priv->can.clock.freq = clk[0] / 2;
180	else
181		priv->can.clock.freq = CLK_DEFAULT / 2;
182
183	if (ocr[idx] != 0xff)
184		priv->ocr = ocr[idx];
185	else if (ocr[0] != 0xff)
186		priv->ocr = ocr[0];
187	else
188		priv->ocr = OCR_DEFAULT;
189
190	if (cdr[idx] != 0xff)
191		priv->cdr = cdr[idx];
192	else if (cdr[0] != 0xff)
193		priv->cdr = cdr[0];
194	else
195		priv->cdr = CDR_DEFAULT;
196
197	platform_set_drvdata(pdev, dev);
198	SET_NETDEV_DEV(dev, &pdev->dev);
199	dev->dev_id = idx;
200
201	err = register_sja1000dev(dev);
202	if (err) {
203		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
204			DRV_NAME, err);
205		goto exit_free;
206	}
207
208	dev_info(&pdev->dev, "%s device registered (reg_base=0x%p, irq=%d)\n",
209		 DRV_NAME, priv->reg_base, dev->irq);
210	return 0;
211
212exit_free:
213	free_sja1000dev(dev);
214exit_unmap:
215	if (mem[idx])
216		iounmap(base);
217exit_release:
218	if (mem[idx])
219		release_mem_region(mem[idx], iosize);
220	else
221		release_region(port[idx], iosize);
222exit:
223	return err;
224}
225
226static void sja1000_isa_remove(struct platform_device *pdev)
227{
228	struct net_device *dev = platform_get_drvdata(pdev);
229	struct sja1000_priv *priv = netdev_priv(dev);
230	int idx = pdev->id;
231
232	unregister_sja1000dev(dev);
233
234	if (mem[idx]) {
235		iounmap(priv->reg_base);
236		release_mem_region(mem[idx], SJA1000_IOSIZE);
237	} else {
238		if (priv->read_reg == sja1000_isa_port_read_reg_indirect)
239			release_region(port[idx], SJA1000_IOSIZE_INDIRECT);
240		else
241			release_region(port[idx], SJA1000_IOSIZE);
242	}
243	free_sja1000dev(dev);
244}
245
246static struct platform_driver sja1000_isa_driver = {
247	.probe = sja1000_isa_probe,
248	.remove_new = sja1000_isa_remove,
249	.driver = {
250		.name = DRV_NAME,
251	},
252};
253
254static int __init sja1000_isa_init(void)
255{
256	int idx, err;
257
258	for (idx = 0; idx < MAXDEV; idx++) {
259		if ((port[idx] || mem[idx]) && irq[idx]) {
260			sja1000_isa_devs[idx] =
261				platform_device_alloc(DRV_NAME, idx);
262			if (!sja1000_isa_devs[idx]) {
263				err = -ENOMEM;
264				goto exit_free_devices;
265			}
266			err = platform_device_add(sja1000_isa_devs[idx]);
267			if (err) {
268				platform_device_put(sja1000_isa_devs[idx]);
269				goto exit_free_devices;
270			}
271			pr_debug("%s: platform device %d: port=%#lx, mem=%#lx, "
272				 "irq=%d\n",
273				 DRV_NAME, idx, port[idx], mem[idx], irq[idx]);
274		} else if (idx == 0 || port[idx] || mem[idx]) {
275				pr_err("%s: insufficient parameters supplied\n",
276				       DRV_NAME);
277				err = -EINVAL;
278				goto exit_free_devices;
279		}
280	}
281
282	err = platform_driver_register(&sja1000_isa_driver);
283	if (err)
284		goto exit_free_devices;
285
286	pr_info("Legacy %s driver for max. %d devices registered\n",
287		DRV_NAME, MAXDEV);
288
289	return 0;
290
291exit_free_devices:
292	while (--idx >= 0) {
293		if (sja1000_isa_devs[idx])
294			platform_device_unregister(sja1000_isa_devs[idx]);
295	}
296
297	return err;
298}
299
300static void __exit sja1000_isa_exit(void)
301{
302	int idx;
303
304	platform_driver_unregister(&sja1000_isa_driver);
305	for (idx = 0; idx < MAXDEV; idx++) {
306		if (sja1000_isa_devs[idx])
307			platform_device_unregister(sja1000_isa_devs[idx]);
308	}
309}
310
311module_init(sja1000_isa_init);
312module_exit(sja1000_isa_exit);
313