xref: /openbmc/linux/drivers/net/can/sja1000/ems_pci.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
4  * Copyright (C) 2008 Markus Plessing <plessing@ems-wuensche.com>
5  * Copyright (C) 2008 Sebastian Haas <haas@ems-wuensche.com>
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/interrupt.h>
11 #include <linux/netdevice.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/pci.h>
15 #include <linux/can/dev.h>
16 #include <linux/io.h>
17 
18 #include "sja1000.h"
19 
20 #define DRV_NAME  "ems_pci"
21 
22 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
23 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
24 MODULE_LICENSE("GPL v2");
25 
26 #define EMS_PCI_V1_MAX_CHAN 2
27 #define EMS_PCI_V2_MAX_CHAN 4
28 #define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN
29 
30 struct ems_pci_card {
31 	int version;
32 	int channels;
33 
34 	struct pci_dev *pci_dev;
35 	struct net_device *net_dev[EMS_PCI_MAX_CHAN];
36 
37 	void __iomem *conf_addr;
38 	void __iomem *base_addr;
39 };
40 
41 #define EMS_PCI_CAN_CLOCK (16000000 / 2)
42 
43 /*
44  * Register definitions and descriptions are from LinCAN 0.3.3.
45  *
46  * PSB4610 PITA-2 bridge control registers
47  */
48 #define PITA2_ICR           0x00	/* Interrupt Control Register */
49 #define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
50 #define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */
51 
52 #define PITA2_MISC          0x1c	/* Miscellaneous Register */
53 #define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */
54 
55 /*
56  * Register definitions for the PLX 9030
57  */
58 #define PLX_ICSR            0x4c   /* Interrupt Control/Status register */
59 #define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
60 #define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
61 #define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
62 #define PLX_ICSR_ENA_CLR    (PLX_ICSR_LINTI1_ENA | PLX_ICSR_PCIINT_ENA | \
63 			     PLX_ICSR_LINTI1_CLR)
64 
65 /*
66  * The board configuration is probably following:
67  * RX1 is connected to ground.
68  * TX1 is not connected.
69  * CLKO is not connected.
70  * Setting the OCR register to 0xDA is a good idea.
71  * This means normal output mode, push-pull and the correct polarity.
72  */
73 #define EMS_PCI_OCR         (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
74 
75 /*
76  * In the CDR register, you should set CBP to 1.
77  * You will probably also want to set the clock divider value to 7
78  * (meaning direct oscillator output) because the second SJA1000 chip
79  * is driven by the first one CLKOUT output.
80  */
81 #define EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)
82 
83 #define EMS_PCI_V1_BASE_BAR     1
84 #define EMS_PCI_V1_CONF_SIZE    4096 /* size of PITA control area */
85 #define EMS_PCI_V2_BASE_BAR     2
86 #define EMS_PCI_V2_CONF_SIZE    128 /* size of PLX control area */
87 #define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
88 #define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */
89 
90 #define EMS_PCI_BASE_SIZE  4096 /* size of controller area */
91 
92 static const struct pci_device_id ems_pci_tbl[] = {
93 	/* CPC-PCI v1 */
94 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
95 	/* CPC-PCI v2 */
96 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
97 	/* CPC-104P v2 */
98 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
99 	{0,}
100 };
101 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
102 
103 /*
104  * Helper to read internal registers from card logic (not CAN)
105  */
106 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
107 {
108 	return readb(card->base_addr + (port * 4));
109 }
110 
111 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
112 {
113 	return readb(priv->reg_base + (port * 4));
114 }
115 
116 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
117 				 int port, u8 val)
118 {
119 	writeb(val, priv->reg_base + (port * 4));
120 }
121 
122 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
123 {
124 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
125 
126 	/* reset int flag of pita */
127 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
128 	       card->conf_addr + PITA2_ICR);
129 }
130 
131 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
132 {
133 	return readb(priv->reg_base + port);
134 }
135 
136 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
137 				 int port, u8 val)
138 {
139 	writeb(val, priv->reg_base + port);
140 }
141 
142 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
143 {
144 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
145 
146 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
147 }
148 
149 /*
150  * Check if a CAN controller is present at the specified location
151  * by trying to set 'em into the PeliCAN mode
152  */
153 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
154 {
155 	unsigned char res;
156 
157 	/* Make sure SJA1000 is in reset mode */
158 	priv->write_reg(priv, SJA1000_MOD, 1);
159 
160 	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);
161 
162 	/* read reset-values */
163 	res = priv->read_reg(priv, SJA1000_CDR);
164 
165 	if (res == CDR_PELICAN)
166 		return 1;
167 
168 	return 0;
169 }
170 
171 static void ems_pci_del_card(struct pci_dev *pdev)
172 {
173 	struct ems_pci_card *card = pci_get_drvdata(pdev);
174 	struct net_device *dev;
175 	int i = 0;
176 
177 	for (i = 0; i < card->channels; i++) {
178 		dev = card->net_dev[i];
179 
180 		if (!dev)
181 			continue;
182 
183 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
184 		unregister_sja1000dev(dev);
185 		free_sja1000dev(dev);
186 	}
187 
188 	if (card->base_addr != NULL)
189 		pci_iounmap(card->pci_dev, card->base_addr);
190 
191 	if (card->conf_addr != NULL)
192 		pci_iounmap(card->pci_dev, card->conf_addr);
193 
194 	kfree(card);
195 
196 	pci_disable_device(pdev);
197 }
198 
199 static void ems_pci_card_reset(struct ems_pci_card *card)
200 {
201 	/* Request board reset */
202 	writeb(0, card->base_addr);
203 }
204 
205 /*
206  * Probe PCI device for EMS CAN signature and register each available
207  * CAN channel to SJA1000 Socket-CAN subsystem.
208  */
209 static int ems_pci_add_card(struct pci_dev *pdev,
210 			    const struct pci_device_id *ent)
211 {
212 	struct sja1000_priv *priv;
213 	struct net_device *dev;
214 	struct ems_pci_card *card;
215 	int max_chan, conf_size, base_bar;
216 	int err, i;
217 
218 	/* Enabling PCI device */
219 	if (pci_enable_device(pdev) < 0) {
220 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
221 		return -ENODEV;
222 	}
223 
224 	/* Allocating card structures to hold addresses, ... */
225 	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
226 	if (card == NULL) {
227 		pci_disable_device(pdev);
228 		return -ENOMEM;
229 	}
230 
231 	pci_set_drvdata(pdev, card);
232 
233 	card->pci_dev = pdev;
234 
235 	card->channels = 0;
236 
237 	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
238 		card->version = 2; /* CPC-PCI v2 */
239 		max_chan = EMS_PCI_V2_MAX_CHAN;
240 		base_bar = EMS_PCI_V2_BASE_BAR;
241 		conf_size = EMS_PCI_V2_CONF_SIZE;
242 	} else {
243 		card->version = 1; /* CPC-PCI v1 */
244 		max_chan = EMS_PCI_V1_MAX_CHAN;
245 		base_bar = EMS_PCI_V1_BASE_BAR;
246 		conf_size = EMS_PCI_V1_CONF_SIZE;
247 	}
248 
249 	/* Remap configuration space and controller memory area */
250 	card->conf_addr = pci_iomap(pdev, 0, conf_size);
251 	if (card->conf_addr == NULL) {
252 		err = -ENOMEM;
253 		goto failure_cleanup;
254 	}
255 
256 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
257 	if (card->base_addr == NULL) {
258 		err = -ENOMEM;
259 		goto failure_cleanup;
260 	}
261 
262 	if (card->version == 1) {
263 		/* Configure PITA-2 parallel interface (enable MUX) */
264 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
265 
266 		/* Check for unique EMS CAN signature */
267 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
268 		    ems_pci_v1_readb(card, 1) != 0xAA ||
269 		    ems_pci_v1_readb(card, 2) != 0x01 ||
270 		    ems_pci_v1_readb(card, 3) != 0xCB ||
271 		    ems_pci_v1_readb(card, 4) != 0x11) {
272 			dev_err(&pdev->dev,
273 				"Not EMS Dr. Thomas Wuensche interface\n");
274 			err = -ENODEV;
275 			goto failure_cleanup;
276 		}
277 	}
278 
279 	ems_pci_card_reset(card);
280 
281 	/* Detect available channels */
282 	for (i = 0; i < max_chan; i++) {
283 		dev = alloc_sja1000dev(0);
284 		if (dev == NULL) {
285 			err = -ENOMEM;
286 			goto failure_cleanup;
287 		}
288 
289 		card->net_dev[i] = dev;
290 		priv = netdev_priv(dev);
291 		priv->priv = card;
292 		priv->irq_flags = IRQF_SHARED;
293 
294 		dev->irq = pdev->irq;
295 		priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
296 					+ (i * EMS_PCI_CAN_CTRL_SIZE);
297 		if (card->version == 1) {
298 			priv->read_reg  = ems_pci_v1_read_reg;
299 			priv->write_reg = ems_pci_v1_write_reg;
300 			priv->post_irq  = ems_pci_v1_post_irq;
301 		} else {
302 			priv->read_reg  = ems_pci_v2_read_reg;
303 			priv->write_reg = ems_pci_v2_write_reg;
304 			priv->post_irq  = ems_pci_v2_post_irq;
305 		}
306 
307 		/* Check if channel is present */
308 		if (ems_pci_check_chan(priv)) {
309 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
310 			priv->ocr = EMS_PCI_OCR;
311 			priv->cdr = EMS_PCI_CDR;
312 
313 			SET_NETDEV_DEV(dev, &pdev->dev);
314 			dev->dev_id = i;
315 
316 			if (card->version == 1)
317 				/* reset int flag of pita */
318 				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
319 				       card->conf_addr + PITA2_ICR);
320 			else
321 				/* enable IRQ in PLX 9030 */
322 				writel(PLX_ICSR_ENA_CLR,
323 				       card->conf_addr + PLX_ICSR);
324 
325 			/* Register SJA1000 device */
326 			err = register_sja1000dev(dev);
327 			if (err) {
328 				dev_err(&pdev->dev, "Registering device failed "
329 							"(err=%d)\n", err);
330 				free_sja1000dev(dev);
331 				goto failure_cleanup;
332 			}
333 
334 			card->channels++;
335 
336 			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
337 					i + 1, priv->reg_base, dev->irq);
338 		} else {
339 			free_sja1000dev(dev);
340 		}
341 	}
342 
343 	return 0;
344 
345 failure_cleanup:
346 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
347 
348 	ems_pci_del_card(pdev);
349 
350 	return err;
351 }
352 
353 static struct pci_driver ems_pci_driver = {
354 	.name = DRV_NAME,
355 	.id_table = ems_pci_tbl,
356 	.probe = ems_pci_add_card,
357 	.remove = ems_pci_del_card,
358 };
359 
360 module_pci_driver(ems_pci_driver);
361