1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2008 Sebastian Haas (initial chardev implementation)
4 * Copyright (C) 2010 Markus Plessing <plessing@ems-wuensche.com>
5 * Rework for mainline by Oliver Hartkopp <socketcan@hartkopp.net>
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/io.h>
14 #include <pcmcia/cistpl.h>
15 #include <pcmcia/ds.h>
16 #include <linux/can.h>
17 #include <linux/can/dev.h>
18 #include "sja1000.h"
19
20 #define DRV_NAME "ems_pcmcia"
21
22 MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>");
23 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");
24 MODULE_LICENSE("GPL v2");
25
26 #define EMS_PCMCIA_MAX_CHAN 2
27
28 struct ems_pcmcia_card {
29 int channels;
30 struct pcmcia_device *pcmcia_dev;
31 struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];
32 void __iomem *base_addr;
33 };
34
35 #define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)
36
37 /*
38 * The board configuration is probably following:
39 * RX1 is connected to ground.
40 * TX1 is not connected.
41 * CLKO is not connected.
42 * Setting the OCR register to 0xDA is a good idea.
43 * This means normal output mode , push-pull and the correct polarity.
44 */
45 #define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
46
47 /*
48 * In the CDR register, you should set CBP to 1.
49 * You will probably also want to set the clock divider value to 7
50 * (meaning direct oscillator output) because the second SJA1000 chip
51 * is driven by the first one CLKOUT output.
52 */
53 #define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)
54 #define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */
55 #define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */
56 #define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */
57
58 #define EMS_CMD_RESET 0x00 /* Perform a reset of the card */
59 #define EMS_CMD_MAP 0x03 /* Map CAN controllers into card' memory */
60 #define EMS_CMD_UMAP 0x02 /* Unmap CAN controllers from card' memory */
61
62 static struct pcmcia_device_id ems_pcmcia_tbl[] = {
63 PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23,
64 0xa338573f, 0xe4575800),
65 PCMCIA_DEVICE_NULL,
66 };
67
68 MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);
69
ems_pcmcia_read_reg(const struct sja1000_priv * priv,int port)70 static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)
71 {
72 return readb(priv->reg_base + port);
73 }
74
ems_pcmcia_write_reg(const struct sja1000_priv * priv,int port,u8 val)75 static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port,
76 u8 val)
77 {
78 writeb(val, priv->reg_base + port);
79 }
80
ems_pcmcia_interrupt(int irq,void * dev_id)81 static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id)
82 {
83 struct ems_pcmcia_card *card = dev_id;
84 struct net_device *dev;
85 irqreturn_t retval = IRQ_NONE;
86 int i, again;
87
88 /* Card not present */
89 if (readw(card->base_addr) != 0xAA55)
90 return IRQ_HANDLED;
91
92 do {
93 again = 0;
94
95 /* Check interrupt for each channel */
96 for (i = 0; i < card->channels; i++) {
97 dev = card->net_dev[i];
98 if (!dev)
99 continue;
100
101 if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)
102 again = 1;
103 }
104 /* At least one channel handled the interrupt */
105 if (again)
106 retval = IRQ_HANDLED;
107
108 } while (again);
109
110 return retval;
111 }
112
113 /*
114 * Check if a CAN controller is present at the specified location
115 * by trying to set 'em into the PeliCAN mode
116 */
ems_pcmcia_check_chan(struct sja1000_priv * priv)117 static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv)
118 {
119 /* Make sure SJA1000 is in reset mode */
120 ems_pcmcia_write_reg(priv, SJA1000_MOD, 1);
121 ems_pcmcia_write_reg(priv, SJA1000_CDR, CDR_PELICAN);
122
123 /* read reset-values */
124 if (ems_pcmcia_read_reg(priv, SJA1000_CDR) == CDR_PELICAN)
125 return 1;
126
127 return 0;
128 }
129
ems_pcmcia_del_card(struct pcmcia_device * pdev)130 static void ems_pcmcia_del_card(struct pcmcia_device *pdev)
131 {
132 struct ems_pcmcia_card *card = pdev->priv;
133 struct net_device *dev;
134 int i;
135
136 free_irq(pdev->irq, card);
137
138 for (i = 0; i < card->channels; i++) {
139 dev = card->net_dev[i];
140 if (!dev)
141 continue;
142
143 printk(KERN_INFO "%s: removing %s on channel #%d\n",
144 DRV_NAME, dev->name, i);
145 unregister_sja1000dev(dev);
146 free_sja1000dev(dev);
147 }
148
149 writeb(EMS_CMD_UMAP, card->base_addr);
150 iounmap(card->base_addr);
151 kfree(card);
152
153 pdev->priv = NULL;
154 }
155
156 /*
157 * Probe PCI device for EMS CAN signature and register each available
158 * CAN channel to SJA1000 Socket-CAN subsystem.
159 */
ems_pcmcia_add_card(struct pcmcia_device * pdev,unsigned long base)160 static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base)
161 {
162 struct sja1000_priv *priv;
163 struct net_device *dev;
164 struct ems_pcmcia_card *card;
165 int err, i;
166
167 /* Allocating card structures to hold addresses, ... */
168 card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL);
169 if (!card)
170 return -ENOMEM;
171
172 pdev->priv = card;
173 card->channels = 0;
174
175 card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);
176 if (!card->base_addr) {
177 err = -ENOMEM;
178 goto failure_cleanup;
179 }
180
181 /* Check for unique EMS CAN signature */
182 if (readw(card->base_addr) != 0xAA55) {
183 err = -ENODEV;
184 goto failure_cleanup;
185 }
186
187 /* Request board reset */
188 writeb(EMS_CMD_RESET, card->base_addr);
189
190 /* Make sure CAN controllers are mapped into card's memory space */
191 writeb(EMS_CMD_MAP, card->base_addr);
192
193 /* Detect available channels */
194 for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {
195 dev = alloc_sja1000dev(0);
196 if (!dev) {
197 err = -ENOMEM;
198 goto failure_cleanup;
199 }
200
201 card->net_dev[i] = dev;
202 priv = netdev_priv(dev);
203 priv->priv = card;
204 SET_NETDEV_DEV(dev, &pdev->dev);
205 dev->dev_id = i;
206
207 priv->irq_flags = IRQF_SHARED;
208 dev->irq = pdev->irq;
209 priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
210 (i * EMS_PCMCIA_CAN_CTRL_SIZE);
211
212 /* Check if channel is present */
213 if (ems_pcmcia_check_chan(priv)) {
214 priv->read_reg = ems_pcmcia_read_reg;
215 priv->write_reg = ems_pcmcia_write_reg;
216 priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
217 priv->ocr = EMS_PCMCIA_OCR;
218 priv->cdr = EMS_PCMCIA_CDR;
219 priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;
220
221 /* Register SJA1000 device */
222 err = register_sja1000dev(dev);
223 if (err) {
224 free_sja1000dev(dev);
225 goto failure_cleanup;
226 }
227
228 card->channels++;
229
230 printk(KERN_INFO "%s: registered %s on channel "
231 "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
232 i, priv->reg_base, dev->irq);
233 } else
234 free_sja1000dev(dev);
235 }
236
237 if (!card->channels) {
238 err = -ENODEV;
239 goto failure_cleanup;
240 }
241
242 err = request_irq(pdev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
243 DRV_NAME, card);
244 if (!err)
245 return 0;
246
247 failure_cleanup:
248 ems_pcmcia_del_card(pdev);
249 return err;
250 }
251
252 /*
253 * Setup PCMCIA socket and probe for EMS CPC-CARD
254 */
ems_pcmcia_probe(struct pcmcia_device * dev)255 static int ems_pcmcia_probe(struct pcmcia_device *dev)
256 {
257 int csval;
258
259 /* General socket configuration */
260 dev->config_flags |= CONF_ENABLE_IRQ;
261 dev->config_index = 1;
262 dev->config_regs = PRESENT_OPTION;
263
264 /* The io structure describes IO port mapping */
265 dev->resource[0]->end = 16;
266 dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
267 dev->resource[1]->end = 16;
268 dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
269 dev->io_lines = 5;
270
271 /* Allocate a memory window */
272 dev->resource[2]->flags =
273 (WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
274 dev->resource[2]->start = dev->resource[2]->end = 0;
275
276 csval = pcmcia_request_window(dev, dev->resource[2], 0);
277 if (csval) {
278 dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",
279 csval);
280 return 0;
281 }
282
283 csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
284 if (csval) {
285 dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",
286 csval);
287 return 0;
288 }
289
290 csval = pcmcia_enable_device(dev);
291 if (csval) {
292 dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",
293 csval);
294 return 0;
295 }
296
297 ems_pcmcia_add_card(dev, dev->resource[2]->start);
298 return 0;
299 }
300
301 /*
302 * Release claimed resources
303 */
ems_pcmcia_remove(struct pcmcia_device * dev)304 static void ems_pcmcia_remove(struct pcmcia_device *dev)
305 {
306 ems_pcmcia_del_card(dev);
307 pcmcia_disable_device(dev);
308 }
309
310 static struct pcmcia_driver ems_pcmcia_driver = {
311 .name = DRV_NAME,
312 .probe = ems_pcmcia_probe,
313 .remove = ems_pcmcia_remove,
314 .id_table = ems_pcmcia_tbl,
315 };
316 module_pcmcia_driver(ems_pcmcia_driver);
317