xref: /openbmc/linux/drivers/net/can/sja1000/ems_pci.c (revision b8265621)
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_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe/104P CAN card");
25 MODULE_LICENSE("GPL v2");
26 
27 #define EMS_PCI_V1_MAX_CHAN 2
28 #define EMS_PCI_V2_MAX_CHAN 4
29 #define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN
30 
31 struct ems_pci_card {
32 	int version;
33 	int channels;
34 
35 	struct pci_dev *pci_dev;
36 	struct net_device *net_dev[EMS_PCI_MAX_CHAN];
37 
38 	void __iomem *conf_addr;
39 	void __iomem *base_addr;
40 };
41 
42 #define EMS_PCI_CAN_CLOCK (16000000 / 2)
43 
44 /*
45  * Register definitions and descriptions are from LinCAN 0.3.3.
46  *
47  * PSB4610 PITA-2 bridge control registers
48  */
49 #define PITA2_ICR           0x00	/* Interrupt Control Register */
50 #define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
51 #define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */
52 
53 #define PITA2_MISC          0x1c	/* Miscellaneous Register */
54 #define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */
55 
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 /*
67  * The board configuration is probably following:
68  * RX1 is connected to ground.
69  * TX1 is not connected.
70  * CLKO is not connected.
71  * Setting the OCR register to 0xDA is a good idea.
72  * This means normal output mode, push-pull and the correct polarity.
73  */
74 #define EMS_PCI_OCR         (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
75 
76 /*
77  * In the CDR register, you should set CBP to 1.
78  * You will probably also want to set the clock divider value to 7
79  * (meaning direct oscillator output) because the second SJA1000 chip
80  * is driven by the first one CLKOUT output.
81  */
82 #define EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)
83 
84 #define EMS_PCI_V1_BASE_BAR     1
85 #define EMS_PCI_V1_CONF_SIZE    4096 /* size of PITA control area */
86 #define EMS_PCI_V2_BASE_BAR     2
87 #define EMS_PCI_V2_CONF_SIZE    128 /* size of PLX control area */
88 #define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
89 #define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */
90 
91 #define EMS_PCI_BASE_SIZE  4096 /* size of controller area */
92 
93 static const struct pci_device_id ems_pci_tbl[] = {
94 	/* CPC-PCI v1 */
95 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
96 	/* CPC-PCI v2 */
97 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
98 	/* CPC-104P v2 */
99 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
100 	{0,}
101 };
102 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
103 
104 /*
105  * Helper to read internal registers from card logic (not CAN)
106  */
107 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
108 {
109 	return readb(card->base_addr + (port * 4));
110 }
111 
112 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
113 {
114 	return readb(priv->reg_base + (port * 4));
115 }
116 
117 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
118 				 int port, u8 val)
119 {
120 	writeb(val, priv->reg_base + (port * 4));
121 }
122 
123 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
124 {
125 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
126 
127 	/* reset int flag of pita */
128 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
129 	       card->conf_addr + PITA2_ICR);
130 }
131 
132 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
133 {
134 	return readb(priv->reg_base + port);
135 }
136 
137 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
138 				 int port, u8 val)
139 {
140 	writeb(val, priv->reg_base + port);
141 }
142 
143 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
144 {
145 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
146 
147 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
148 }
149 
150 /*
151  * Check if a CAN controller is present at the specified location
152  * by trying to set 'em into the PeliCAN mode
153  */
154 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
155 {
156 	unsigned char res;
157 
158 	/* Make sure SJA1000 is in reset mode */
159 	priv->write_reg(priv, SJA1000_MOD, 1);
160 
161 	priv->write_reg(priv, SJA1000_CDR, CDR_PELICAN);
162 
163 	/* read reset-values */
164 	res = priv->read_reg(priv, SJA1000_CDR);
165 
166 	if (res == CDR_PELICAN)
167 		return 1;
168 
169 	return 0;
170 }
171 
172 static void ems_pci_del_card(struct pci_dev *pdev)
173 {
174 	struct ems_pci_card *card = pci_get_drvdata(pdev);
175 	struct net_device *dev;
176 	int i = 0;
177 
178 	for (i = 0; i < card->channels; i++) {
179 		dev = card->net_dev[i];
180 
181 		if (!dev)
182 			continue;
183 
184 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
185 		unregister_sja1000dev(dev);
186 		free_sja1000dev(dev);
187 	}
188 
189 	if (card->base_addr != NULL)
190 		pci_iounmap(card->pci_dev, card->base_addr);
191 
192 	if (card->conf_addr != NULL)
193 		pci_iounmap(card->pci_dev, card->conf_addr);
194 
195 	kfree(card);
196 
197 	pci_disable_device(pdev);
198 }
199 
200 static void ems_pci_card_reset(struct ems_pci_card *card)
201 {
202 	/* Request board reset */
203 	writeb(0, card->base_addr);
204 }
205 
206 /*
207  * Probe PCI device for EMS CAN signature and register each available
208  * CAN channel to SJA1000 Socket-CAN subsystem.
209  */
210 static int ems_pci_add_card(struct pci_dev *pdev,
211 			    const struct pci_device_id *ent)
212 {
213 	struct sja1000_priv *priv;
214 	struct net_device *dev;
215 	struct ems_pci_card *card;
216 	int max_chan, conf_size, base_bar;
217 	int err, i;
218 
219 	/* Enabling PCI device */
220 	if (pci_enable_device(pdev) < 0) {
221 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
222 		return -ENODEV;
223 	}
224 
225 	/* Allocating card structures to hold addresses, ... */
226 	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
227 	if (card == NULL) {
228 		pci_disable_device(pdev);
229 		return -ENOMEM;
230 	}
231 
232 	pci_set_drvdata(pdev, card);
233 
234 	card->pci_dev = pdev;
235 
236 	card->channels = 0;
237 
238 	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
239 		card->version = 2; /* CPC-PCI v2 */
240 		max_chan = EMS_PCI_V2_MAX_CHAN;
241 		base_bar = EMS_PCI_V2_BASE_BAR;
242 		conf_size = EMS_PCI_V2_CONF_SIZE;
243 	} else {
244 		card->version = 1; /* CPC-PCI v1 */
245 		max_chan = EMS_PCI_V1_MAX_CHAN;
246 		base_bar = EMS_PCI_V1_BASE_BAR;
247 		conf_size = EMS_PCI_V1_CONF_SIZE;
248 	}
249 
250 	/* Remap configuration space and controller memory area */
251 	card->conf_addr = pci_iomap(pdev, 0, conf_size);
252 	if (card->conf_addr == NULL) {
253 		err = -ENOMEM;
254 		goto failure_cleanup;
255 	}
256 
257 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
258 	if (card->base_addr == NULL) {
259 		err = -ENOMEM;
260 		goto failure_cleanup;
261 	}
262 
263 	if (card->version == 1) {
264 		/* Configure PITA-2 parallel interface (enable MUX) */
265 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
266 
267 		/* Check for unique EMS CAN signature */
268 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
269 		    ems_pci_v1_readb(card, 1) != 0xAA ||
270 		    ems_pci_v1_readb(card, 2) != 0x01 ||
271 		    ems_pci_v1_readb(card, 3) != 0xCB ||
272 		    ems_pci_v1_readb(card, 4) != 0x11) {
273 			dev_err(&pdev->dev,
274 				"Not EMS Dr. Thomas Wuensche interface\n");
275 			err = -ENODEV;
276 			goto failure_cleanup;
277 		}
278 	}
279 
280 	ems_pci_card_reset(card);
281 
282 	/* Detect available channels */
283 	for (i = 0; i < max_chan; i++) {
284 		dev = alloc_sja1000dev(0);
285 		if (dev == NULL) {
286 			err = -ENOMEM;
287 			goto failure_cleanup;
288 		}
289 
290 		card->net_dev[i] = dev;
291 		priv = netdev_priv(dev);
292 		priv->priv = card;
293 		priv->irq_flags = IRQF_SHARED;
294 
295 		dev->irq = pdev->irq;
296 		priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
297 					+ (i * EMS_PCI_CAN_CTRL_SIZE);
298 		if (card->version == 1) {
299 			priv->read_reg  = ems_pci_v1_read_reg;
300 			priv->write_reg = ems_pci_v1_write_reg;
301 			priv->post_irq  = ems_pci_v1_post_irq;
302 		} else {
303 			priv->read_reg  = ems_pci_v2_read_reg;
304 			priv->write_reg = ems_pci_v2_write_reg;
305 			priv->post_irq  = ems_pci_v2_post_irq;
306 		}
307 
308 		/* Check if channel is present */
309 		if (ems_pci_check_chan(priv)) {
310 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
311 			priv->ocr = EMS_PCI_OCR;
312 			priv->cdr = EMS_PCI_CDR;
313 
314 			SET_NETDEV_DEV(dev, &pdev->dev);
315 			dev->dev_id = i;
316 
317 			if (card->version == 1)
318 				/* reset int flag of pita */
319 				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
320 				       card->conf_addr + PITA2_ICR);
321 			else
322 				/* enable IRQ in PLX 9030 */
323 				writel(PLX_ICSR_ENA_CLR,
324 				       card->conf_addr + PLX_ICSR);
325 
326 			/* Register SJA1000 device */
327 			err = register_sja1000dev(dev);
328 			if (err) {
329 				dev_err(&pdev->dev, "Registering device failed "
330 							"(err=%d)\n", err);
331 				free_sja1000dev(dev);
332 				goto failure_cleanup;
333 			}
334 
335 			card->channels++;
336 
337 			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
338 					i + 1, priv->reg_base, dev->irq);
339 		} else {
340 			free_sja1000dev(dev);
341 		}
342 	}
343 
344 	return 0;
345 
346 failure_cleanup:
347 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
348 
349 	ems_pci_del_card(pdev);
350 
351 	return err;
352 }
353 
354 static struct pci_driver ems_pci_driver = {
355 	.name = DRV_NAME,
356 	.id_table = ems_pci_tbl,
357 	.probe = ems_pci_add_card,
358 	.remove = ems_pci_del_card,
359 };
360 
361 module_pci_driver(ems_pci_driver);
362