summaryrefslogtreecommitdiffstats
path: root/drivers/net/can/sja1000/ems_pci.c
blob: fd13dbf07d9c0cb3d912c99f326b6e31be965366 (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
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
/*
 * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
 * Copyright (C) 2008 Markus Plessing <plessing@ems-wuensche.com>
 * Copyright (C) 2008 Sebastian Haas <haas@ems-wuensche.com>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/can/dev.h>
#include <linux/io.h>

#include "sja1000.h"

#define DRV_NAME  "ems_pci"

MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
MODULE_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe/104P CAN card");
MODULE_LICENSE("GPL v2");

#define EMS_PCI_V1_MAX_CHAN 2
#define EMS_PCI_V2_MAX_CHAN 4
#define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN

struct ems_pci_card {
	int version;
	int channels;

	struct pci_dev *pci_dev;
	struct net_device *net_dev[EMS_PCI_MAX_CHAN];

	void __iomem *conf_addr;
	void __iomem *base_addr;
};

#define EMS_PCI_CAN_CLOCK (16000000 / 2)

/*
 * Register definitions and descriptions are from LinCAN 0.3.3.
 *
 * PSB4610 PITA-2 bridge control registers
 */
#define PITA2_ICR           0x00	/* Interrupt Control Register */
#define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
#define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */

#define PITA2_MISC          0x1c	/* Miscellaneous Register */
#define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */

/*
 * Register definitions for the PLX 9030
 */
#define PLX_ICSR            0x4c   /* Interrupt Control/Status register */
#define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
#define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
#define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
#define PLX_ICSR_ENA_CLR    (PLX_ICSR_LINTI1_ENA | PLX_ICSR_PCIINT_ENA | \
			     PLX_ICSR_LINTI1_CLR)

/*
 * 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_PCI_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_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)

#define EMS_PCI_V1_BASE_BAR     1
#define EMS_PCI_V1_CONF_SIZE    4096 /* size of PITA control area */
#define EMS_PCI_V2_BASE_BAR     2
#define EMS_PCI_V2_CONF_SIZE    128 /* size of PLX control area */
#define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
#define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */

#define EMS_PCI_BASE_SIZE  4096 /* size of controller area */

static DEFINE_PCI_DEVICE_TABLE(ems_pci_tbl) = {
	/* CPC-PCI v1 */
	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
	/* CPC-PCI v2 */
	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
	/* CPC-104P v2 */
	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
	{0,}
};
MODULE_DEVICE_TABLE(pci, ems_pci_tbl);

/*
 * Helper to read internal registers from card logic (not CAN)
 */
static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
{
	return readb(card->base_addr + (port * 4));
}

static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
{
	return readb(priv->reg_base + (port * 4));
}

static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
				 int port, u8 val)
{
	writeb(val, priv->reg_base + (port * 4));
}

static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
{
	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;

	/* reset int flag of pita */
	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
	       card->conf_addr + PITA2_ICR);
}

static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
{
	return readb(priv->reg_base + port);
}

static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
				 int port, u8 val)
{
	writeb(val, priv->reg_base + port);
}

static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
{
	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;

	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
}

/*
 * Check if a CAN controller is present at the specified location
 * by trying to set 'em into the PeliCAN mode
 */
static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
{
	unsigned char res;

	/* Make sure SJA1000 is in reset mode */
	priv->write_reg(priv, SJA1000_MOD, 1);

	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);

	/* read reset-values */
	res = priv->read_reg(priv, SJA1000_CDR);

	if (res == CDR_PELICAN)
		return 1;

	return 0;
}

static void ems_pci_del_card(struct pci_dev *pdev)
{
	struct ems_pci_card *card = pci_get_drvdata(pdev);
	struct net_device *dev;
	int i = 0;

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

		if (!dev)
			continue;

		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
		unregister_sja1000dev(dev);
		free_sja1000dev(dev);
	}

	if (card->base_addr != NULL)
		pci_iounmap(card->pci_dev, card->base_addr);

	if (card->conf_addr != NULL)
		pci_iounmap(card->pci_dev, card->conf_addr);

	kfree(card);

	pci_disable_device(pdev);
}

static void ems_pci_card_reset(struct ems_pci_card *card)
{
	/* Request board reset */
	writeb(0, card->base_addr);
}

/*
 * Probe PCI device for EMS CAN signature and register each available
 * CAN channel to SJA1000 Socket-CAN subsystem.
 */
static int ems_pci_add_card(struct pci_dev *pdev,
			    const struct pci_device_id *ent)
{
	struct sja1000_priv *priv;
	struct net_device *dev;
	struct ems_pci_card *card;
	int max_chan, conf_size, base_bar;
	int err, i;

	/* Enabling PCI device */
	if (pci_enable_device(pdev) < 0) {
		dev_err(&pdev->dev, "Enabling PCI device failed\n");
		return -ENODEV;
	}

	/* Allocating card structures to hold addresses, ... */
	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
	if (card == NULL) {
		pci_disable_device(pdev);
		return -ENOMEM;
	}

	pci_set_drvdata(pdev, card);

	card->pci_dev = pdev;

	card->channels = 0;

	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
		card->version = 2; /* CPC-PCI v2 */
		max_chan = EMS_PCI_V2_MAX_CHAN;
		base_bar = EMS_PCI_V2_BASE_BAR;
		conf_size = EMS_PCI_V2_CONF_SIZE;
	} else {
		card->version = 1; /* CPC-PCI v1 */
		max_chan = EMS_PCI_V1_MAX_CHAN;
		base_bar = EMS_PCI_V1_BASE_BAR;
		conf_size = EMS_PCI_V1_CONF_SIZE;
	}

	/* Remap configuration space and controller memory area */
	card->conf_addr = pci_iomap(pdev, 0, conf_size);
	if (card->conf_addr == NULL) {
		err = -ENOMEM;
		goto failure_cleanup;
	}

	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
	if (card->base_addr == NULL) {
		err = -ENOMEM;
		goto failure_cleanup;
	}

	if (card->version == 1) {
		/* Configure PITA-2 parallel interface (enable MUX) */
		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);

		/* Check for unique EMS CAN signature */
		if (ems_pci_v1_readb(card, 0) != 0x55 ||
		    ems_pci_v1_readb(card, 1) != 0xAA ||
		    ems_pci_v1_readb(card, 2) != 0x01 ||
		    ems_pci_v1_readb(card, 3) != 0xCB ||
		    ems_pci_v1_readb(card, 4) != 0x11) {
			dev_err(&pdev->dev,
				"Not EMS Dr. Thomas Wuensche interface\n");
			err = -ENODEV;
			goto failure_cleanup;
		}
	}

	ems_pci_card_reset(card);

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

		card->net_dev[i] = dev;
		priv = netdev_priv(dev);
		priv->priv = card;
		priv->irq_flags = IRQF_SHARED;

		dev->irq = pdev->irq;
		priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
					+ (i * EMS_PCI_CAN_CTRL_SIZE);
		if (card->version == 1) {
			priv->read_reg  = ems_pci_v1_read_reg;
			priv->write_reg = ems_pci_v1_write_reg;
			priv->post_irq  = ems_pci_v1_post_irq;
		} else {
			priv->read_reg  = ems_pci_v2_read_reg;
			priv->write_reg = ems_pci_v2_write_reg;
			priv->post_irq  = ems_pci_v2_post_irq;
		}

		/* Check if channel is present */
		if (ems_pci_check_chan(priv)) {
			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
			priv->ocr = EMS_PCI_OCR;
			priv->cdr = EMS_PCI_CDR;

			SET_NETDEV_DEV(dev, &pdev->dev);
			dev->dev_id = i;

			if (card->version == 1)
				/* reset int flag of pita */
				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
				       card->conf_addr + PITA2_ICR);
			else
				/* enable IRQ in PLX 9030 */
				writel(PLX_ICSR_ENA_CLR,
				       card->conf_addr + PLX_ICSR);

			/* Register SJA1000 device */
			err = register_sja1000dev(dev);
			if (err) {
				dev_err(&pdev->dev, "Registering device failed "
							"(err=%d)\n", err);
				free_sja1000dev(dev);
				goto failure_cleanup;
			}

			card->channels++;

			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
					i + 1, priv->reg_base, dev->irq);
		} else {
			free_sja1000dev(dev);
		}
	}

	return 0;

failure_cleanup:
	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);

	ems_pci_del_card(pdev);

	return err;
}

static struct pci_driver ems_pci_driver = {
	.name = DRV_NAME,
	.id_table = ems_pci_tbl,
	.probe = ems_pci_add_card,
	.remove = ems_pci_del_card,
};

module_pci_driver(ems_pci_driver);