xref: /openbmc/linux/drivers/net/can/sja1000/ems_pci.c (revision 9cfc5c90)
1 /*
2  * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
3  * Copyright (C) 2008 Markus Plessing <plessing@ems-wuensche.com>
4  * Copyright (C) 2008 Sebastian Haas <haas@ems-wuensche.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the version 2 of the GNU General Public License
8  * as published by the Free Software Foundation
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/interrupt.h>
22 #include <linux/netdevice.h>
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/pci.h>
26 #include <linux/can/dev.h>
27 #include <linux/io.h>
28 
29 #include "sja1000.h"
30 
31 #define DRV_NAME  "ems_pci"
32 
33 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
34 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
35 MODULE_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe/104P CAN card");
36 MODULE_LICENSE("GPL v2");
37 
38 #define EMS_PCI_V1_MAX_CHAN 2
39 #define EMS_PCI_V2_MAX_CHAN 4
40 #define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN
41 
42 struct ems_pci_card {
43 	int version;
44 	int channels;
45 
46 	struct pci_dev *pci_dev;
47 	struct net_device *net_dev[EMS_PCI_MAX_CHAN];
48 
49 	void __iomem *conf_addr;
50 	void __iomem *base_addr;
51 };
52 
53 #define EMS_PCI_CAN_CLOCK (16000000 / 2)
54 
55 /*
56  * Register definitions and descriptions are from LinCAN 0.3.3.
57  *
58  * PSB4610 PITA-2 bridge control registers
59  */
60 #define PITA2_ICR           0x00	/* Interrupt Control Register */
61 #define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
62 #define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */
63 
64 #define PITA2_MISC          0x1c	/* Miscellaneous Register */
65 #define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */
66 
67 /*
68  * Register definitions for the PLX 9030
69  */
70 #define PLX_ICSR            0x4c   /* Interrupt Control/Status register */
71 #define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
72 #define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
73 #define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
74 #define PLX_ICSR_ENA_CLR    (PLX_ICSR_LINTI1_ENA | PLX_ICSR_PCIINT_ENA | \
75 			     PLX_ICSR_LINTI1_CLR)
76 
77 /*
78  * The board configuration is probably following:
79  * RX1 is connected to ground.
80  * TX1 is not connected.
81  * CLKO is not connected.
82  * Setting the OCR register to 0xDA is a good idea.
83  * This means normal output mode, push-pull and the correct polarity.
84  */
85 #define EMS_PCI_OCR         (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
86 
87 /*
88  * In the CDR register, you should set CBP to 1.
89  * You will probably also want to set the clock divider value to 7
90  * (meaning direct oscillator output) because the second SJA1000 chip
91  * is driven by the first one CLKOUT output.
92  */
93 #define EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)
94 
95 #define EMS_PCI_V1_BASE_BAR     1
96 #define EMS_PCI_V1_CONF_SIZE    4096 /* size of PITA control area */
97 #define EMS_PCI_V2_BASE_BAR     2
98 #define EMS_PCI_V2_CONF_SIZE    128 /* size of PLX control area */
99 #define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
100 #define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */
101 
102 #define EMS_PCI_BASE_SIZE  4096 /* size of controller area */
103 
104 static const struct pci_device_id ems_pci_tbl[] = {
105 	/* CPC-PCI v1 */
106 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
107 	/* CPC-PCI v2 */
108 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
109 	/* CPC-104P v2 */
110 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
111 	{0,}
112 };
113 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
114 
115 /*
116  * Helper to read internal registers from card logic (not CAN)
117  */
118 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
119 {
120 	return readb(card->base_addr + (port * 4));
121 }
122 
123 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
124 {
125 	return readb(priv->reg_base + (port * 4));
126 }
127 
128 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
129 				 int port, u8 val)
130 {
131 	writeb(val, priv->reg_base + (port * 4));
132 }
133 
134 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
135 {
136 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
137 
138 	/* reset int flag of pita */
139 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
140 	       card->conf_addr + PITA2_ICR);
141 }
142 
143 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
144 {
145 	return readb(priv->reg_base + port);
146 }
147 
148 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
149 				 int port, u8 val)
150 {
151 	writeb(val, priv->reg_base + port);
152 }
153 
154 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
155 {
156 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
157 
158 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
159 }
160 
161 /*
162  * Check if a CAN controller is present at the specified location
163  * by trying to set 'em into the PeliCAN mode
164  */
165 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
166 {
167 	unsigned char res;
168 
169 	/* Make sure SJA1000 is in reset mode */
170 	priv->write_reg(priv, SJA1000_MOD, 1);
171 
172 	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);
173 
174 	/* read reset-values */
175 	res = priv->read_reg(priv, SJA1000_CDR);
176 
177 	if (res == CDR_PELICAN)
178 		return 1;
179 
180 	return 0;
181 }
182 
183 static void ems_pci_del_card(struct pci_dev *pdev)
184 {
185 	struct ems_pci_card *card = pci_get_drvdata(pdev);
186 	struct net_device *dev;
187 	int i = 0;
188 
189 	for (i = 0; i < card->channels; i++) {
190 		dev = card->net_dev[i];
191 
192 		if (!dev)
193 			continue;
194 
195 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
196 		unregister_sja1000dev(dev);
197 		free_sja1000dev(dev);
198 	}
199 
200 	if (card->base_addr != NULL)
201 		pci_iounmap(card->pci_dev, card->base_addr);
202 
203 	if (card->conf_addr != NULL)
204 		pci_iounmap(card->pci_dev, card->conf_addr);
205 
206 	kfree(card);
207 
208 	pci_disable_device(pdev);
209 }
210 
211 static void ems_pci_card_reset(struct ems_pci_card *card)
212 {
213 	/* Request board reset */
214 	writeb(0, card->base_addr);
215 }
216 
217 /*
218  * Probe PCI device for EMS CAN signature and register each available
219  * CAN channel to SJA1000 Socket-CAN subsystem.
220  */
221 static int ems_pci_add_card(struct pci_dev *pdev,
222 			    const struct pci_device_id *ent)
223 {
224 	struct sja1000_priv *priv;
225 	struct net_device *dev;
226 	struct ems_pci_card *card;
227 	int max_chan, conf_size, base_bar;
228 	int err, i;
229 
230 	/* Enabling PCI device */
231 	if (pci_enable_device(pdev) < 0) {
232 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
233 		return -ENODEV;
234 	}
235 
236 	/* Allocating card structures to hold addresses, ... */
237 	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
238 	if (card == NULL) {
239 		pci_disable_device(pdev);
240 		return -ENOMEM;
241 	}
242 
243 	pci_set_drvdata(pdev, card);
244 
245 	card->pci_dev = pdev;
246 
247 	card->channels = 0;
248 
249 	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
250 		card->version = 2; /* CPC-PCI v2 */
251 		max_chan = EMS_PCI_V2_MAX_CHAN;
252 		base_bar = EMS_PCI_V2_BASE_BAR;
253 		conf_size = EMS_PCI_V2_CONF_SIZE;
254 	} else {
255 		card->version = 1; /* CPC-PCI v1 */
256 		max_chan = EMS_PCI_V1_MAX_CHAN;
257 		base_bar = EMS_PCI_V1_BASE_BAR;
258 		conf_size = EMS_PCI_V1_CONF_SIZE;
259 	}
260 
261 	/* Remap configuration space and controller memory area */
262 	card->conf_addr = pci_iomap(pdev, 0, conf_size);
263 	if (card->conf_addr == NULL) {
264 		err = -ENOMEM;
265 		goto failure_cleanup;
266 	}
267 
268 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
269 	if (card->base_addr == NULL) {
270 		err = -ENOMEM;
271 		goto failure_cleanup;
272 	}
273 
274 	if (card->version == 1) {
275 		/* Configure PITA-2 parallel interface (enable MUX) */
276 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
277 
278 		/* Check for unique EMS CAN signature */
279 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
280 		    ems_pci_v1_readb(card, 1) != 0xAA ||
281 		    ems_pci_v1_readb(card, 2) != 0x01 ||
282 		    ems_pci_v1_readb(card, 3) != 0xCB ||
283 		    ems_pci_v1_readb(card, 4) != 0x11) {
284 			dev_err(&pdev->dev,
285 				"Not EMS Dr. Thomas Wuensche interface\n");
286 			err = -ENODEV;
287 			goto failure_cleanup;
288 		}
289 	}
290 
291 	ems_pci_card_reset(card);
292 
293 	/* Detect available channels */
294 	for (i = 0; i < max_chan; i++) {
295 		dev = alloc_sja1000dev(0);
296 		if (dev == NULL) {
297 			err = -ENOMEM;
298 			goto failure_cleanup;
299 		}
300 
301 		card->net_dev[i] = dev;
302 		priv = netdev_priv(dev);
303 		priv->priv = card;
304 		priv->irq_flags = IRQF_SHARED;
305 
306 		dev->irq = pdev->irq;
307 		priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
308 					+ (i * EMS_PCI_CAN_CTRL_SIZE);
309 		if (card->version == 1) {
310 			priv->read_reg  = ems_pci_v1_read_reg;
311 			priv->write_reg = ems_pci_v1_write_reg;
312 			priv->post_irq  = ems_pci_v1_post_irq;
313 		} else {
314 			priv->read_reg  = ems_pci_v2_read_reg;
315 			priv->write_reg = ems_pci_v2_write_reg;
316 			priv->post_irq  = ems_pci_v2_post_irq;
317 		}
318 
319 		/* Check if channel is present */
320 		if (ems_pci_check_chan(priv)) {
321 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
322 			priv->ocr = EMS_PCI_OCR;
323 			priv->cdr = EMS_PCI_CDR;
324 
325 			SET_NETDEV_DEV(dev, &pdev->dev);
326 			dev->dev_id = i;
327 
328 			if (card->version == 1)
329 				/* reset int flag of pita */
330 				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
331 				       card->conf_addr + PITA2_ICR);
332 			else
333 				/* enable IRQ in PLX 9030 */
334 				writel(PLX_ICSR_ENA_CLR,
335 				       card->conf_addr + PLX_ICSR);
336 
337 			/* Register SJA1000 device */
338 			err = register_sja1000dev(dev);
339 			if (err) {
340 				dev_err(&pdev->dev, "Registering device failed "
341 							"(err=%d)\n", err);
342 				free_sja1000dev(dev);
343 				goto failure_cleanup;
344 			}
345 
346 			card->channels++;
347 
348 			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
349 					i + 1, priv->reg_base, dev->irq);
350 		} else {
351 			free_sja1000dev(dev);
352 		}
353 	}
354 
355 	return 0;
356 
357 failure_cleanup:
358 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
359 
360 	ems_pci_del_card(pdev);
361 
362 	return err;
363 }
364 
365 static struct pci_driver ems_pci_driver = {
366 	.name = DRV_NAME,
367 	.id_table = ems_pci_tbl,
368 	.probe = ems_pci_add_card,
369 	.remove = ems_pci_del_card,
370 };
371 
372 module_pci_driver(ems_pci_driver);
373