aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/can/sja1000/ems_pcmcia.c
blob: 5c2f3fbbf5ae8fc4028ecf0fdc50ac03e92fd21b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
/*
 * Copyright (C) 2008 Sebastian Haas (initial chardev implementation)
 * Copyright (C) 2010 Markus Plessing <plessing@ems-wuensche.com>
 * Rework for mainline by Oliver Hartkopp <socketcan@hartkopp.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include "sja1000.h"

#define DRV_NAME "ems_pcmcia"

MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>");
MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");
MODULE_SUPPORTED_DEVICE("EMS CPC-CARD CAN card");
MODULE_LICENSE("GPL v2");

#define EMS_PCMCIA_MAX_CHAN 2

struct ems_pcmcia_card {
	int channels;
	struct pcmcia_device *pcmcia_dev;
	struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];
	void __iomem *base_addr;
};

#define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)

/*
 * The board configuration is probably following:
 * RX1 is connected to ground.
 * TX1 is not connected.
 * CLKO is not connected.
 * Setting the OCR register to 0xDA is a good idea.
 * This means  normal output mode , push-pull and the correct polarity.
 */
#define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)

/*
 * In the CDR register, you should set CBP to 1.
 * You will probably also want to set the clock divider value to 7
 * (meaning direct oscillator output) because the second SJA1000 chip
 * is driven by the first one CLKOUT output.
 */
#define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)
#define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */
#define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */
#define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */

#define EMS_CMD_RESET 0x00 /* Perform a reset of the card */
#define EMS_CMD_MAP   0x03 /* Map CAN controllers into card' memory */
#define EMS_CMD_UMAP  0x02 /* Unmap CAN controllers from card' memory */

static struct pcmcia_device_id ems_pcmcia_tbl[] = {
	PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23,
				 0xa338573f, 0xe4575800),
	PCMCIA_DEVICE_NULL,
};

MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);

static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)
{
	return readb(priv->reg_base + port);
}

static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port,
				 u8 val)
{
	writeb(val, priv->reg_base + port);
}

static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id)
{
	struct ems_pcmcia_card *card = dev_id;
	struct net_device *dev;
	irqreturn_t retval = IRQ_NONE;
	int i, again;

	/* Card not present */
	if (readw(card->base_addr) != 0xAA55)
		return IRQ_HANDLED;

	do {
		again = 0;

		/* Check interrupt for each channel */
		for (i = 0; i < card->channels; i++) {
			dev = card->net_dev[i];
			if (!dev)
				continue;

			if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)
				again = 1;
		}
		/* At least one channel handled the interrupt */
		if (again)
			retval = IRQ_HANDLED;

	} while (again);

	return retval;
}

/*
 * Check if a CAN controller is present at the specified location
 * by trying to set 'em into the PeliCAN mode
 */
static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv)
{
	/* Make sure SJA1000 is in reset mode */
	ems_pcmcia_write_reg(priv, REG_MOD, 1);
	ems_pcmcia_write_reg(priv, REG_CDR, CDR_PELICAN);

	/* read reset-values */
	if (ems_pcmcia_read_reg(priv, REG_CDR) == CDR_PELICAN)
		return 1;

	return 0;
}

static void ems_pcmcia_del_card(struct pcmcia_device *pdev)
{
	struct ems_pcmcia_card *card = pdev->priv;
	struct net_device *dev;
	int i;

	free_irq(pdev->irq, card);

	for (i = 0; i < card->channels; i++) {
		dev = card->net_dev[i];
		if (!dev)
			continue;

		printk(KERN_INFO "%s: removing %s on channel #%d\n",
		       DRV_NAME, dev->name, i);
		unregister_sja1000dev(dev);
		free_sja1000dev(dev);
	}

	writeb(EMS_CMD_UMAP, card->base_addr);
	iounmap(card->base_addr);
	kfree(card);

	pdev->priv = NULL;
}

/*
 * Probe PCI device for EMS CAN signature and register each available
 * CAN channel to SJA1000 Socket-CAN subsystem.
 */
static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base)
{
	struct sja1000_priv *priv;
	struct net_device *dev;
	struct ems_pcmcia_card *card;
	int err, i;

	/* Allocating card structures to hold addresses, ... */
	card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL);
	if (!card)
		return -ENOMEM;

	pdev->priv = card;
	card->channels = 0;

	card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);
	if (!card->base_addr) {
		err = -ENOMEM;
		goto failure_cleanup;
	}

	/* Check for unique EMS CAN signature */
	if (readw(card->base_addr) != 0xAA55) {
		err = -ENODEV;
		goto failure_cleanup;
	}

	/* Request board reset */
	writeb(EMS_CMD_RESET, card->base_addr);

	/* Make sure CAN controllers are mapped into card's memory space */
	writeb(EMS_CMD_MAP, card->base_addr);

	/* Detect available channels */
	for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {
		dev = alloc_sja1000dev(0);
		if (!dev) {
			err = -ENOMEM;
			goto failure_cleanup;
		}

		card->net_dev[i] = dev;
		priv = netdev_priv(dev);
		priv->priv = card;
		SET_NETDEV_DEV(dev, &pdev->dev);

		priv->irq_flags = IRQF_SHARED;
		dev->irq = pdev->irq;
		priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
			(i * EMS_PCMCIA_CAN_CTRL_SIZE);

		/* Check if channel is present */
		if (ems_pcmcia_check_chan(priv)) {
			priv->read_reg  = ems_pcmcia_read_reg;
			priv->write_reg = ems_pcmcia_write_reg;
			priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
			priv->ocr = EMS_PCMCIA_OCR;
			priv->cdr = EMS_PCMCIA_CDR;
			priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;

			/* Register SJA1000 device */
			err = register_sja1000dev(dev);
			if (err) {
				free_sja1000dev(dev);
				goto failure_cleanup;
			}

			card->channels++;

			printk(KERN_INFO "%s: registered %s on channel "
			       "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
			       i, priv->reg_base, dev->irq);
		} else
			free_sja1000dev(dev);
	}

	err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
			  DRV_NAME, card);
	if (!err)
		return 0;

failure_cleanup:
	ems_pcmcia_del_card(pdev);
	return err;
}

/*
 * Setup PCMCIA socket and probe for EMS CPC-CARD
 */
static int ems_pcmcia_probe(struct pcmcia_device *dev)
{
	int csval;

	/* General socket configuration */
	dev->config_flags |= CONF_ENABLE_IRQ;
	dev->config_index = 1;
	dev->config_regs = PRESENT_OPTION;

	/* The io structure describes IO port mapping */
	dev->resource[0]->end = 16;
	dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
	dev->resource[1]->end = 16;
	dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
	dev->io_lines = 5;

	/* Allocate a memory window */
	dev->resource[2]->flags =
		(WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
	dev->resource[2]->start = dev->resource[2]->end = 0;

	csval = pcmcia_request_window(dev, dev->resource[2], 0);
	if (csval) {
		dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",
			csval);
		return 0;
	}

	csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
	if (csval) {
		dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",
			csval);
		return 0;
	}

	csval = pcmcia_enable_device(dev);
	if (csval) {
		dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",
			csval);
		return 0;
	}

	ems_pcmcia_add_card(dev, dev->resource[2]->start);
	return 0;
}

/*
 * Release claimed resources
 */
static void ems_pcmcia_remove(struct pcmcia_device *dev)
{
	ems_pcmcia_del_card(dev);
	pcmcia_disable_device(dev);
}

static struct pcmcia_driver ems_pcmcia_driver = {
	.name = DRV_NAME,
	.probe = ems_pcmcia_probe,
	.remove = ems_pcmcia_remove,
	.id_table = ems_pcmcia_tbl,
};

static int __init ems_pcmcia_init(void)
{
	return pcmcia_register_driver(&ems_pcmcia_driver);
}
module_init(ems_pcmcia_init);

static void __exit ems_pcmcia_exit(void)
{
	pcmcia_unregister_driver(&ems_pcmcia_driver);
}
module_exit(ems_pcmcia_exit);