xref: /openbmc/linux/drivers/net/can/sja1000/ems_pci.c (revision bc000245)
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, write to the Free Software Foundation,
17  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/interrupt.h>
23 #include <linux/netdevice.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/pci.h>
27 #include <linux/can/dev.h>
28 #include <linux/io.h>
29 
30 #include "sja1000.h"
31 
32 #define DRV_NAME  "ems_pci"
33 
34 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
35 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
36 MODULE_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe/104P CAN card");
37 MODULE_LICENSE("GPL v2");
38 
39 #define EMS_PCI_V1_MAX_CHAN 2
40 #define EMS_PCI_V2_MAX_CHAN 4
41 #define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN
42 
43 struct ems_pci_card {
44 	int version;
45 	int channels;
46 
47 	struct pci_dev *pci_dev;
48 	struct net_device *net_dev[EMS_PCI_MAX_CHAN];
49 
50 	void __iomem *conf_addr;
51 	void __iomem *base_addr;
52 };
53 
54 #define EMS_PCI_CAN_CLOCK (16000000 / 2)
55 
56 /*
57  * Register definitions and descriptions are from LinCAN 0.3.3.
58  *
59  * PSB4610 PITA-2 bridge control registers
60  */
61 #define PITA2_ICR           0x00	/* Interrupt Control Register */
62 #define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
63 #define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */
64 
65 #define PITA2_MISC          0x1c	/* Miscellaneous Register */
66 #define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */
67 
68 /*
69  * Register definitions for the PLX 9030
70  */
71 #define PLX_ICSR            0x4c   /* Interrupt Control/Status register */
72 #define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
73 #define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
74 #define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
75 #define PLX_ICSR_ENA_CLR    (PLX_ICSR_LINTI1_ENA | PLX_ICSR_PCIINT_ENA | \
76 			     PLX_ICSR_LINTI1_CLR)
77 
78 /*
79  * The board configuration is probably following:
80  * RX1 is connected to ground.
81  * TX1 is not connected.
82  * CLKO is not connected.
83  * Setting the OCR register to 0xDA is a good idea.
84  * This means normal output mode, push-pull and the correct polarity.
85  */
86 #define EMS_PCI_OCR         (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
87 
88 /*
89  * In the CDR register, you should set CBP to 1.
90  * You will probably also want to set the clock divider value to 7
91  * (meaning direct oscillator output) because the second SJA1000 chip
92  * is driven by the first one CLKOUT output.
93  */
94 #define EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)
95 
96 #define EMS_PCI_V1_BASE_BAR     1
97 #define EMS_PCI_V1_CONF_SIZE    4096 /* size of PITA control area */
98 #define EMS_PCI_V2_BASE_BAR     2
99 #define EMS_PCI_V2_CONF_SIZE    128 /* size of PLX control area */
100 #define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
101 #define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */
102 
103 #define EMS_PCI_BASE_SIZE  4096 /* size of controller area */
104 
105 static DEFINE_PCI_DEVICE_TABLE(ems_pci_tbl) = {
106 	/* CPC-PCI v1 */
107 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
108 	/* CPC-PCI v2 */
109 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
110 	/* CPC-104P v2 */
111 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
112 	{0,}
113 };
114 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
115 
116 /*
117  * Helper to read internal registers from card logic (not CAN)
118  */
119 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
120 {
121 	return readb(card->base_addr + (port * 4));
122 }
123 
124 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
125 {
126 	return readb(priv->reg_base + (port * 4));
127 }
128 
129 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
130 				 int port, u8 val)
131 {
132 	writeb(val, priv->reg_base + (port * 4));
133 }
134 
135 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
136 {
137 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
138 
139 	/* reset int flag of pita */
140 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
141 	       card->conf_addr + PITA2_ICR);
142 }
143 
144 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
145 {
146 	return readb(priv->reg_base + port);
147 }
148 
149 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
150 				 int port, u8 val)
151 {
152 	writeb(val, priv->reg_base + port);
153 }
154 
155 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
156 {
157 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
158 
159 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
160 }
161 
162 /*
163  * Check if a CAN controller is present at the specified location
164  * by trying to set 'em into the PeliCAN mode
165  */
166 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
167 {
168 	unsigned char res;
169 
170 	/* Make sure SJA1000 is in reset mode */
171 	priv->write_reg(priv, SJA1000_MOD, 1);
172 
173 	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);
174 
175 	/* read reset-values */
176 	res = priv->read_reg(priv, SJA1000_CDR);
177 
178 	if (res == CDR_PELICAN)
179 		return 1;
180 
181 	return 0;
182 }
183 
184 static void ems_pci_del_card(struct pci_dev *pdev)
185 {
186 	struct ems_pci_card *card = pci_get_drvdata(pdev);
187 	struct net_device *dev;
188 	int i = 0;
189 
190 	for (i = 0; i < card->channels; i++) {
191 		dev = card->net_dev[i];
192 
193 		if (!dev)
194 			continue;
195 
196 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
197 		unregister_sja1000dev(dev);
198 		free_sja1000dev(dev);
199 	}
200 
201 	if (card->base_addr != NULL)
202 		pci_iounmap(card->pci_dev, card->base_addr);
203 
204 	if (card->conf_addr != NULL)
205 		pci_iounmap(card->pci_dev, card->conf_addr);
206 
207 	kfree(card);
208 
209 	pci_disable_device(pdev);
210 }
211 
212 static void ems_pci_card_reset(struct ems_pci_card *card)
213 {
214 	/* Request board reset */
215 	writeb(0, card->base_addr);
216 }
217 
218 /*
219  * Probe PCI device for EMS CAN signature and register each available
220  * CAN channel to SJA1000 Socket-CAN subsystem.
221  */
222 static int ems_pci_add_card(struct pci_dev *pdev,
223 			    const struct pci_device_id *ent)
224 {
225 	struct sja1000_priv *priv;
226 	struct net_device *dev;
227 	struct ems_pci_card *card;
228 	int max_chan, conf_size, base_bar;
229 	int err, i;
230 
231 	/* Enabling PCI device */
232 	if (pci_enable_device(pdev) < 0) {
233 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
234 		return -ENODEV;
235 	}
236 
237 	/* Allocating card structures to hold addresses, ... */
238 	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
239 	if (card == NULL) {
240 		pci_disable_device(pdev);
241 		return -ENOMEM;
242 	}
243 
244 	pci_set_drvdata(pdev, card);
245 
246 	card->pci_dev = pdev;
247 
248 	card->channels = 0;
249 
250 	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
251 		card->version = 2; /* CPC-PCI v2 */
252 		max_chan = EMS_PCI_V2_MAX_CHAN;
253 		base_bar = EMS_PCI_V2_BASE_BAR;
254 		conf_size = EMS_PCI_V2_CONF_SIZE;
255 	} else {
256 		card->version = 1; /* CPC-PCI v1 */
257 		max_chan = EMS_PCI_V1_MAX_CHAN;
258 		base_bar = EMS_PCI_V1_BASE_BAR;
259 		conf_size = EMS_PCI_V1_CONF_SIZE;
260 	}
261 
262 	/* Remap configuration space and controller memory area */
263 	card->conf_addr = pci_iomap(pdev, 0, conf_size);
264 	if (card->conf_addr == NULL) {
265 		err = -ENOMEM;
266 		goto failure_cleanup;
267 	}
268 
269 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
270 	if (card->base_addr == NULL) {
271 		err = -ENOMEM;
272 		goto failure_cleanup;
273 	}
274 
275 	if (card->version == 1) {
276 		/* Configure PITA-2 parallel interface (enable MUX) */
277 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
278 
279 		/* Check for unique EMS CAN signature */
280 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
281 		    ems_pci_v1_readb(card, 1) != 0xAA ||
282 		    ems_pci_v1_readb(card, 2) != 0x01 ||
283 		    ems_pci_v1_readb(card, 3) != 0xCB ||
284 		    ems_pci_v1_readb(card, 4) != 0x11) {
285 			dev_err(&pdev->dev,
286 				"Not EMS Dr. Thomas Wuensche interface\n");
287 			err = -ENODEV;
288 			goto failure_cleanup;
289 		}
290 	}
291 
292 	ems_pci_card_reset(card);
293 
294 	/* Detect available channels */
295 	for (i = 0; i < max_chan; i++) {
296 		dev = alloc_sja1000dev(0);
297 		if (dev == NULL) {
298 			err = -ENOMEM;
299 			goto failure_cleanup;
300 		}
301 
302 		card->net_dev[i] = dev;
303 		priv = netdev_priv(dev);
304 		priv->priv = card;
305 		priv->irq_flags = IRQF_SHARED;
306 
307 		dev->irq = pdev->irq;
308 		priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
309 					+ (i * EMS_PCI_CAN_CTRL_SIZE);
310 		if (card->version == 1) {
311 			priv->read_reg  = ems_pci_v1_read_reg;
312 			priv->write_reg = ems_pci_v1_write_reg;
313 			priv->post_irq  = ems_pci_v1_post_irq;
314 		} else {
315 			priv->read_reg  = ems_pci_v2_read_reg;
316 			priv->write_reg = ems_pci_v2_write_reg;
317 			priv->post_irq  = ems_pci_v2_post_irq;
318 		}
319 
320 		/* Check if channel is present */
321 		if (ems_pci_check_chan(priv)) {
322 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
323 			priv->ocr = EMS_PCI_OCR;
324 			priv->cdr = EMS_PCI_CDR;
325 
326 			SET_NETDEV_DEV(dev, &pdev->dev);
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