xref: /openbmc/linux/drivers/net/can/sja1000/ems_pci.c (revision 3ddc8b84)
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 #define PCI_SUBDEVICE_ID_EMS 0x4010
112 
113 static const struct pci_device_id ems_pci_tbl[] = {
114 	/* CPC-PCI v1 */
115 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
116 	/* CPC-PCI v2 */
117 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
118 	/* CPC-104P v2 */
119 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
120 	/* CPC-PCIe v3 */
121 	{PCI_VENDOR_ID_ASIX, PCI_DEVICE_ID_ASIX_AX99100_LB, 0xa000, PCI_SUBDEVICE_ID_EMS},
122 	{0,}
123 };
124 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
125 
126 /* Helper to read internal registers from card logic (not CAN)
127  */
128 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
129 {
130 	return readb(card->base_addr + (port * 4));
131 }
132 
133 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
134 {
135 	return readb(priv->reg_base + (port * 4));
136 }
137 
138 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
139 				 int port, u8 val)
140 {
141 	writeb(val, priv->reg_base + (port * 4));
142 }
143 
144 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
145 {
146 	struct ems_pci_card *card = priv->priv;
147 
148 	/* reset int flag of pita */
149 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
150 	       card->conf_addr + PITA2_ICR);
151 }
152 
153 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
154 {
155 	return readb(priv->reg_base + port);
156 }
157 
158 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
159 				 int port, u8 val)
160 {
161 	writeb(val, priv->reg_base + port);
162 }
163 
164 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
165 {
166 	struct ems_pci_card *card = priv->priv;
167 
168 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
169 }
170 
171 static u8 ems_pci_v3_read_reg(const struct sja1000_priv *priv, int port)
172 {
173 	return readb(priv->reg_base + port);
174 }
175 
176 static void ems_pci_v3_write_reg(const struct sja1000_priv *priv,
177 				 int port, u8 val)
178 {
179 	writeb(val, priv->reg_base + port);
180 }
181 
182 static void ems_pci_v3_post_irq(const struct sja1000_priv *priv)
183 {
184 	struct ems_pci_card *card = priv->priv;
185 
186 	writel(ASIX_LINTSR_INT0AC, card->conf_addr + ASIX_LINTSR);
187 }
188 
189 /* Check if a CAN controller is present at the specified location
190  * by trying to set 'em into the PeliCAN mode
191  */
192 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
193 {
194 	unsigned char res;
195 
196 	/* Make sure SJA1000 is in reset mode */
197 	priv->write_reg(priv, SJA1000_MOD, 1);
198 
199 	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);
200 
201 	/* read reset-values */
202 	res = priv->read_reg(priv, SJA1000_CDR);
203 
204 	if (res == CDR_PELICAN)
205 		return 1;
206 
207 	return 0;
208 }
209 
210 static void ems_pci_del_card(struct pci_dev *pdev)
211 {
212 	struct ems_pci_card *card = pci_get_drvdata(pdev);
213 	struct net_device *dev;
214 	int i = 0;
215 
216 	for (i = 0; i < card->channels; i++) {
217 		dev = card->net_dev[i];
218 
219 		if (!dev)
220 			continue;
221 
222 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
223 		unregister_sja1000dev(dev);
224 		free_sja1000dev(dev);
225 	}
226 
227 	if (card->base_addr)
228 		pci_iounmap(card->pci_dev, card->base_addr);
229 
230 	if (card->conf_addr)
231 		pci_iounmap(card->pci_dev, card->conf_addr);
232 
233 	kfree(card);
234 
235 	pci_disable_device(pdev);
236 }
237 
238 static void ems_pci_card_reset(struct ems_pci_card *card)
239 {
240 	/* Request board reset */
241 	writeb(0, card->base_addr);
242 }
243 
244 /* Probe PCI device for EMS CAN signature and register each available
245  * CAN channel to SJA1000 Socket-CAN subsystem.
246  */
247 static int ems_pci_add_card(struct pci_dev *pdev,
248 			    const struct pci_device_id *ent)
249 {
250 	struct sja1000_priv *priv;
251 	struct net_device *dev;
252 	struct ems_pci_card *card;
253 	int max_chan, conf_size, base_bar, conf_bar;
254 	int err, i;
255 
256 	/* Enabling PCI device */
257 	if (pci_enable_device(pdev) < 0) {
258 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
259 		return -ENODEV;
260 	}
261 
262 	/* Allocating card structures to hold addresses, ... */
263 	card = kzalloc(sizeof(*card), GFP_KERNEL);
264 	if (!card) {
265 		pci_disable_device(pdev);
266 		return -ENOMEM;
267 	}
268 
269 	pci_set_drvdata(pdev, card);
270 
271 	card->pci_dev = pdev;
272 
273 	card->channels = 0;
274 
275 	if (pdev->vendor == PCI_VENDOR_ID_ASIX) {
276 		card->version = 3; /* CPC-PCI v3 */
277 		max_chan = EMS_PCI_V3_MAX_CHAN;
278 		base_bar = EMS_PCI_V3_BASE_BAR;
279 		conf_bar = EMS_PCI_V3_CONF_BAR;
280 		conf_size = EMS_PCI_V3_CONF_SIZE;
281 	} else if (pdev->vendor == PCI_VENDOR_ID_PLX) {
282 		card->version = 2; /* CPC-PCI v2 */
283 		max_chan = EMS_PCI_V2_MAX_CHAN;
284 		base_bar = EMS_PCI_V2_BASE_BAR;
285 		conf_bar = EMS_PCI_V2_CONF_BAR;
286 		conf_size = EMS_PCI_V2_CONF_SIZE;
287 	} else {
288 		card->version = 1; /* CPC-PCI v1 */
289 		max_chan = EMS_PCI_V1_MAX_CHAN;
290 		base_bar = EMS_PCI_V1_BASE_BAR;
291 		conf_bar = EMS_PCI_V1_CONF_BAR;
292 		conf_size = EMS_PCI_V1_CONF_SIZE;
293 	}
294 
295 	/* Remap configuration space and controller memory area */
296 	card->conf_addr = pci_iomap(pdev, conf_bar, conf_size);
297 	if (!card->conf_addr) {
298 		err = -ENOMEM;
299 		goto failure_cleanup;
300 	}
301 
302 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
303 	if (!card->base_addr) {
304 		err = -ENOMEM;
305 		goto failure_cleanup;
306 	}
307 
308 	if (card->version == 1) {
309 		/* Configure PITA-2 parallel interface (enable MUX) */
310 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
311 
312 		/* Check for unique EMS CAN signature */
313 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
314 		    ems_pci_v1_readb(card, 1) != 0xAA ||
315 		    ems_pci_v1_readb(card, 2) != 0x01 ||
316 		    ems_pci_v1_readb(card, 3) != 0xCB ||
317 		    ems_pci_v1_readb(card, 4) != 0x11) {
318 			dev_err(&pdev->dev,
319 				"Not EMS Dr. Thomas Wuensche interface\n");
320 			err = -ENODEV;
321 			goto failure_cleanup;
322 		}
323 	}
324 
325 	if (card->version == 3) {
326 		/* ASIX chip asserts local reset to CAN controllers
327 		 * after bootup until it is deasserted
328 		 */
329 		writel(readl(card->conf_addr + ASIX_LIEMR) & ~ASIX_LIEMR_LRST,
330 		       card->conf_addr + ASIX_LIEMR);
331 	}
332 
333 	ems_pci_card_reset(card);
334 
335 	/* Detect available channels */
336 	for (i = 0; i < max_chan; i++) {
337 		dev = alloc_sja1000dev(0);
338 		if (!dev) {
339 			err = -ENOMEM;
340 			goto failure_cleanup;
341 		}
342 
343 		card->net_dev[i] = dev;
344 		priv = netdev_priv(dev);
345 		priv->priv = card;
346 		priv->irq_flags = IRQF_SHARED;
347 
348 		dev->irq = pdev->irq;
349 
350 		if (card->version == 1) {
351 			priv->read_reg  = ems_pci_v1_read_reg;
352 			priv->write_reg = ems_pci_v1_write_reg;
353 			priv->post_irq  = ems_pci_v1_post_irq;
354 			priv->reg_base = card->base_addr + EMS_PCI_V1_CAN_BASE_OFFSET
355 					+ (i * EMS_PCI_V1_CAN_CTRL_SIZE);
356 		} else if (card->version == 2) {
357 			priv->read_reg  = ems_pci_v2_read_reg;
358 			priv->write_reg = ems_pci_v2_write_reg;
359 			priv->post_irq  = ems_pci_v2_post_irq;
360 			priv->reg_base = card->base_addr + EMS_PCI_V2_CAN_BASE_OFFSET
361 					+ (i * EMS_PCI_V2_CAN_CTRL_SIZE);
362 		} else {
363 			priv->read_reg  = ems_pci_v3_read_reg;
364 			priv->write_reg = ems_pci_v3_write_reg;
365 			priv->post_irq  = ems_pci_v3_post_irq;
366 			priv->reg_base = card->base_addr + EMS_PCI_V3_CAN_BASE_OFFSET
367 					+ (i * EMS_PCI_V3_CAN_CTRL_SIZE);
368 		}
369 
370 		/* Check if channel is present */
371 		if (ems_pci_check_chan(priv)) {
372 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
373 			priv->ocr = EMS_PCI_OCR;
374 			priv->cdr = EMS_PCI_CDR;
375 
376 			SET_NETDEV_DEV(dev, &pdev->dev);
377 			dev->dev_id = i;
378 
379 			if (card->version == 1) {
380 				/* reset int flag of pita */
381 				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
382 				       card->conf_addr + PITA2_ICR);
383 			} else if (card->version == 2) {
384 				/* enable IRQ in PLX 9030 */
385 				writel(PLX_ICSR_ENA_CLR,
386 				       card->conf_addr + PLX_ICSR);
387 			} else {
388 				/* Enable IRQ in AX99100 */
389 				writel(ASIX_LINTSR_INT0AC, card->conf_addr + ASIX_LINTSR);
390 				/* Enable local INT0 input enable */
391 				writel(readl(card->conf_addr + ASIX_LIEMR) | ASIX_LIEMR_L0EINTEN,
392 				       card->conf_addr + ASIX_LIEMR);
393 			}
394 
395 			/* Register SJA1000 device */
396 			err = register_sja1000dev(dev);
397 			if (err) {
398 				dev_err(&pdev->dev,
399 					"Registering device failed: %pe\n",
400 					ERR_PTR(err));
401 				free_sja1000dev(dev);
402 				goto failure_cleanup;
403 			}
404 
405 			card->channels++;
406 
407 			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
408 				 i + 1, priv->reg_base, dev->irq);
409 		} else {
410 			free_sja1000dev(dev);
411 		}
412 	}
413 
414 	return 0;
415 
416 failure_cleanup:
417 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
418 
419 	ems_pci_del_card(pdev);
420 
421 	return err;
422 }
423 
424 static struct pci_driver ems_pci_driver = {
425 	.name = DRV_NAME,
426 	.id_table = ems_pci_tbl,
427 	.probe = ems_pci_add_card,
428 	.remove = ems_pci_del_card,
429 };
430 
431 module_pci_driver(ems_pci_driver);
432