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