xref: /openbmc/linux/drivers/net/can/sja1000/ems_pci.c (revision 47ebd031)
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  * Copyright (C) 2023 EMS Dr. Thomas Wuensche
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/interrupt.h>
12 #include <linux/netdevice.h>
13 #include <linux/delay.h>
14 #include <linux/slab.h>
15 #include <linux/pci.h>
16 #include <linux/can/dev.h>
17 #include <linux/io.h>
18 
19 #include "sja1000.h"
20 
21 #define DRV_NAME  "ems_pci"
22 
23 MODULE_AUTHOR("Sebastian Haas <support@ems-wuensche.com>");
24 MODULE_AUTHOR("Gerhard Uttenthaler <uttenthaler@ems-wuensche.com>");
25 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
26 MODULE_LICENSE("GPL v2");
27 
28 #define EMS_PCI_V1_MAX_CHAN 2
29 #define EMS_PCI_V2_MAX_CHAN 4
30 #define EMS_PCI_V3_MAX_CHAN 4
31 #define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN
32 
33 struct ems_pci_card {
34 	int version;
35 	int channels;
36 
37 	struct pci_dev *pci_dev;
38 	struct net_device *net_dev[EMS_PCI_MAX_CHAN];
39 
40 	void __iomem *conf_addr;
41 	void __iomem *base_addr;
42 };
43 
44 #define EMS_PCI_CAN_CLOCK (16000000 / 2)
45 
46 /* Register definitions and descriptions are from LinCAN 0.3.3.
47  *
48  * PSB4610 PITA-2 bridge control registers
49  */
50 #define PITA2_ICR           0x00	/* Interrupt Control Register */
51 #define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
52 #define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */
53 
54 #define PITA2_MISC          0x1c	/* Miscellaneous Register */
55 #define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */
56 
57 /* Register definitions for the PLX 9030
58  */
59 #define PLX_ICSR            0x4c   /* Interrupt Control/Status register */
60 #define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
61 #define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
62 #define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
63 #define PLX_ICSR_ENA_CLR    (PLX_ICSR_LINTI1_ENA | PLX_ICSR_PCIINT_ENA | \
64 			     PLX_ICSR_LINTI1_CLR)
65 
66 /* Register definitions for the ASIX99100
67  */
68 #define ASIX_LINTSR 0x28 /* Interrupt Control/Status register */
69 #define ASIX_LINTSR_INT0AC BIT(0) /* Writing 1 enables or clears interrupt */
70 
71 #define ASIX_LIEMR 0x24 /* Local Interrupt Enable / Miscellaneous Register */
72 #define ASIX_LIEMR_L0EINTEN BIT(16) /* Local INT0 input assertion enable */
73 #define ASIX_LIEMR_LRST BIT(14) /* Local Reset assert */
74 
75 /* The board configuration is probably following:
76  * RX1 is connected to ground.
77  * TX1 is not connected.
78  * CLKO is not connected.
79  * Setting the OCR register to 0xDA is a good idea.
80  * This means normal output mode, push-pull and the correct polarity.
81  */
82 #define EMS_PCI_OCR         (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
83 
84 /* In the CDR register, you should set CBP to 1.
85  * You will probably also want to set the clock divider value to 7
86  * (meaning direct oscillator output) because the second SJA1000 chip
87  * is driven by the first one CLKOUT output.
88  */
89 #define EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)
90 
91 #define EMS_PCI_V1_BASE_BAR 1
92 #define EMS_PCI_V1_CONF_BAR 0
93 #define EMS_PCI_V1_CONF_SIZE 4096 /* size of PITA control area */
94 #define EMS_PCI_V1_CAN_BASE_OFFSET 0x400 /* offset where the controllers start */
95 #define EMS_PCI_V1_CAN_CTRL_SIZE 0x200 /* memory size for each controller */
96 
97 #define EMS_PCI_V2_BASE_BAR 2
98 #define EMS_PCI_V2_CONF_BAR 0
99 #define EMS_PCI_V2_CONF_SIZE 128 /* size of PLX control area */
100 #define EMS_PCI_V2_CAN_BASE_OFFSET 0x400 /* offset where the controllers start */
101 #define EMS_PCI_V2_CAN_CTRL_SIZE 0x200 /* memory size for each controller */
102 
103 #define EMS_PCI_V3_BASE_BAR 0
104 #define EMS_PCI_V3_CONF_BAR 5
105 #define EMS_PCI_V3_CONF_SIZE 128 /* size of ASIX control area */
106 #define EMS_PCI_V3_CAN_BASE_OFFSET 0x00 /* offset where the controllers starts */
107 #define EMS_PCI_V3_CAN_CTRL_SIZE 0x100 /* memory size for each controller */
108 
109 #define EMS_PCI_BASE_SIZE  4096 /* size of controller area */
110 
111 #ifndef PCI_VENDOR_ID_ASIX
112 #define PCI_VENDOR_ID_ASIX 0x125b
113 #define PCI_DEVICE_ID_ASIX_9110 0x9110
114 #define PCI_SUBVENDOR_ID_ASIX 0xa000
115 #endif
116 #define PCI_SUBDEVICE_ID_EMS 0x4010
117 
118 static const struct pci_device_id ems_pci_tbl[] = {
119 	/* CPC-PCI v1 */
120 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
121 	/* CPC-PCI v2 */
122 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
123 	/* CPC-104P v2 */
124 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
125 	/* CPC-PCIe v3 */
126 	{PCI_VENDOR_ID_ASIX, PCI_DEVICE_ID_ASIX_9110, PCI_SUBVENDOR_ID_ASIX, PCI_SUBDEVICE_ID_EMS},
127 	{0,}
128 };
129 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
130 
131 /* Helper to read internal registers from card logic (not CAN)
132  */
133 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
134 {
135 	return readb(card->base_addr + (port * 4));
136 }
137 
138 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
139 {
140 	return readb(priv->reg_base + (port * 4));
141 }
142 
143 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
144 				 int port, u8 val)
145 {
146 	writeb(val, priv->reg_base + (port * 4));
147 }
148 
149 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
150 {
151 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
152 
153 	/* reset int flag of pita */
154 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
155 	       card->conf_addr + PITA2_ICR);
156 }
157 
158 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
159 {
160 	return readb(priv->reg_base + port);
161 }
162 
163 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
164 				 int port, u8 val)
165 {
166 	writeb(val, priv->reg_base + port);
167 }
168 
169 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
170 {
171 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
172 
173 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
174 }
175 
176 static u8 ems_pci_v3_read_reg(const struct sja1000_priv *priv, int port)
177 {
178 	return readb(priv->reg_base + port);
179 }
180 
181 static void ems_pci_v3_write_reg(const struct sja1000_priv *priv,
182 				 int port, u8 val)
183 {
184 	writeb(val, priv->reg_base + port);
185 }
186 
187 static void ems_pci_v3_post_irq(const struct sja1000_priv *priv)
188 {
189 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
190 
191 	writel(ASIX_LINTSR_INT0AC, card->conf_addr + ASIX_LINTSR);
192 }
193 
194 /* Check if a CAN controller is present at the specified location
195  * by trying to set 'em into the PeliCAN mode
196  */
197 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
198 {
199 	unsigned char res;
200 
201 	/* Make sure SJA1000 is in reset mode */
202 	priv->write_reg(priv, SJA1000_MOD, 1);
203 
204 	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);
205 
206 	/* read reset-values */
207 	res = priv->read_reg(priv, SJA1000_CDR);
208 
209 	if (res == CDR_PELICAN)
210 		return 1;
211 
212 	return 0;
213 }
214 
215 static void ems_pci_del_card(struct pci_dev *pdev)
216 {
217 	struct ems_pci_card *card = pci_get_drvdata(pdev);
218 	struct net_device *dev;
219 	int i = 0;
220 
221 	for (i = 0; i < card->channels; i++) {
222 		dev = card->net_dev[i];
223 
224 		if (!dev)
225 			continue;
226 
227 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
228 		unregister_sja1000dev(dev);
229 		free_sja1000dev(dev);
230 	}
231 
232 	if (card->base_addr)
233 		pci_iounmap(card->pci_dev, card->base_addr);
234 
235 	if (card->conf_addr)
236 		pci_iounmap(card->pci_dev, card->conf_addr);
237 
238 	kfree(card);
239 
240 	pci_disable_device(pdev);
241 }
242 
243 static void ems_pci_card_reset(struct ems_pci_card *card)
244 {
245 	/* Request board reset */
246 	writeb(0, card->base_addr);
247 }
248 
249 /* Probe PCI device for EMS CAN signature and register each available
250  * CAN channel to SJA1000 Socket-CAN subsystem.
251  */
252 static int ems_pci_add_card(struct pci_dev *pdev,
253 			    const struct pci_device_id *ent)
254 {
255 	struct sja1000_priv *priv;
256 	struct net_device *dev;
257 	struct ems_pci_card *card;
258 	int max_chan, conf_size, base_bar, conf_bar;
259 	int err, i;
260 
261 	/* Enabling PCI device */
262 	if (pci_enable_device(pdev) < 0) {
263 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
264 		return -ENODEV;
265 	}
266 
267 	/* Allocating card structures to hold addresses, ... */
268 	card = kzalloc(sizeof(*card), GFP_KERNEL);
269 	if (!card) {
270 		pci_disable_device(pdev);
271 		return -ENOMEM;
272 	}
273 
274 	pci_set_drvdata(pdev, card);
275 
276 	card->pci_dev = pdev;
277 
278 	card->channels = 0;
279 
280 	if (pdev->vendor == PCI_VENDOR_ID_ASIX) {
281 		card->version = 3; /* CPC-PCI v3 */
282 		max_chan = EMS_PCI_V3_MAX_CHAN;
283 		base_bar = EMS_PCI_V3_BASE_BAR;
284 		conf_bar = EMS_PCI_V3_CONF_BAR;
285 		conf_size = EMS_PCI_V3_CONF_SIZE;
286 	} else if (pdev->vendor == PCI_VENDOR_ID_PLX) {
287 		card->version = 2; /* CPC-PCI v2 */
288 		max_chan = EMS_PCI_V2_MAX_CHAN;
289 		base_bar = EMS_PCI_V2_BASE_BAR;
290 		conf_bar = EMS_PCI_V2_CONF_BAR;
291 		conf_size = EMS_PCI_V2_CONF_SIZE;
292 	} else {
293 		card->version = 1; /* CPC-PCI v1 */
294 		max_chan = EMS_PCI_V1_MAX_CHAN;
295 		base_bar = EMS_PCI_V1_BASE_BAR;
296 		conf_bar = EMS_PCI_V1_CONF_BAR;
297 		conf_size = EMS_PCI_V1_CONF_SIZE;
298 	}
299 
300 	/* Remap configuration space and controller memory area */
301 	card->conf_addr = pci_iomap(pdev, conf_bar, conf_size);
302 	if (!card->conf_addr) {
303 		err = -ENOMEM;
304 		goto failure_cleanup;
305 	}
306 
307 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
308 	if (!card->base_addr) {
309 		err = -ENOMEM;
310 		goto failure_cleanup;
311 	}
312 
313 	if (card->version == 1) {
314 		/* Configure PITA-2 parallel interface (enable MUX) */
315 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
316 
317 		/* Check for unique EMS CAN signature */
318 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
319 		    ems_pci_v1_readb(card, 1) != 0xAA ||
320 		    ems_pci_v1_readb(card, 2) != 0x01 ||
321 		    ems_pci_v1_readb(card, 3) != 0xCB ||
322 		    ems_pci_v1_readb(card, 4) != 0x11) {
323 			dev_err(&pdev->dev,
324 				"Not EMS Dr. Thomas Wuensche interface\n");
325 			err = -ENODEV;
326 			goto failure_cleanup;
327 		}
328 	}
329 
330 	if (card->version == 3) {
331 		/* ASIX chip asserts local reset to CAN controllers
332 		 * after bootup until it is deasserted
333 		 */
334 		writel(readl(card->conf_addr + ASIX_LIEMR) & ~ASIX_LIEMR_LRST,
335 		       card->conf_addr + ASIX_LIEMR);
336 	}
337 
338 	ems_pci_card_reset(card);
339 
340 	/* Detect available channels */
341 	for (i = 0; i < max_chan; i++) {
342 		dev = alloc_sja1000dev(0);
343 		if (!dev) {
344 			err = -ENOMEM;
345 			goto failure_cleanup;
346 		}
347 
348 		card->net_dev[i] = dev;
349 		priv = netdev_priv(dev);
350 		priv->priv = card;
351 		priv->irq_flags = IRQF_SHARED;
352 
353 		dev->irq = pdev->irq;
354 
355 		if (card->version == 1) {
356 			priv->read_reg  = ems_pci_v1_read_reg;
357 			priv->write_reg = ems_pci_v1_write_reg;
358 			priv->post_irq  = ems_pci_v1_post_irq;
359 			priv->reg_base = card->base_addr + EMS_PCI_V1_CAN_BASE_OFFSET
360 					+ (i * EMS_PCI_V1_CAN_CTRL_SIZE);
361 		} else if (card->version == 2) {
362 			priv->read_reg  = ems_pci_v2_read_reg;
363 			priv->write_reg = ems_pci_v2_write_reg;
364 			priv->post_irq  = ems_pci_v2_post_irq;
365 			priv->reg_base = card->base_addr + EMS_PCI_V2_CAN_BASE_OFFSET
366 					+ (i * EMS_PCI_V2_CAN_CTRL_SIZE);
367 		} else {
368 			priv->read_reg  = ems_pci_v3_read_reg;
369 			priv->write_reg = ems_pci_v3_write_reg;
370 			priv->post_irq  = ems_pci_v3_post_irq;
371 			priv->reg_base = card->base_addr + EMS_PCI_V3_CAN_BASE_OFFSET
372 					+ (i * EMS_PCI_V3_CAN_CTRL_SIZE);
373 		}
374 
375 		/* Check if channel is present */
376 		if (ems_pci_check_chan(priv)) {
377 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
378 			priv->ocr = EMS_PCI_OCR;
379 			priv->cdr = EMS_PCI_CDR;
380 
381 			SET_NETDEV_DEV(dev, &pdev->dev);
382 			dev->dev_id = i;
383 
384 			if (card->version == 1) {
385 				/* reset int flag of pita */
386 				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
387 				       card->conf_addr + PITA2_ICR);
388 			} else if (card->version == 2) {
389 				/* enable IRQ in PLX 9030 */
390 				writel(PLX_ICSR_ENA_CLR,
391 				       card->conf_addr + PLX_ICSR);
392 			} else {
393 				/* Enable IRQ in AX99100 */
394 				writel(ASIX_LINTSR_INT0AC, card->conf_addr + ASIX_LINTSR);
395 				/* Enable local INT0 input enable */
396 				writel(readl(card->conf_addr + ASIX_LIEMR) | ASIX_LIEMR_L0EINTEN,
397 				       card->conf_addr + ASIX_LIEMR);
398 			}
399 
400 			/* Register SJA1000 device */
401 			err = register_sja1000dev(dev);
402 			if (err) {
403 				dev_err(&pdev->dev,
404 					"Registering device failed: %pe\n",
405 					ERR_PTR(err));
406 				free_sja1000dev(dev);
407 				goto failure_cleanup;
408 			}
409 
410 			card->channels++;
411 
412 			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
413 				 i + 1, priv->reg_base, dev->irq);
414 		} else {
415 			free_sja1000dev(dev);
416 		}
417 	}
418 
419 	return 0;
420 
421 failure_cleanup:
422 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
423 
424 	ems_pci_del_card(pdev);
425 
426 	return err;
427 }
428 
429 static struct pci_driver ems_pci_driver = {
430 	.name = DRV_NAME,
431 	.id_table = ems_pci_tbl,
432 	.probe = ems_pci_add_card,
433 	.remove = ems_pci_del_card,
434 };
435 
436 module_pci_driver(ems_pci_driver);
437