aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/mipsnet.c
blob: f79f7ee72ab89488734bcaba2fd9caf4731ab374 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#define DEBUG

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/sched.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <asm/io.h>
#include <asm/mips-boards/simint.h>

#include "mipsnet.h"		/* actual device IO mapping */

#define MIPSNET_VERSION "2005-06-20"

#define mipsnet_reg_address(dev, field) (dev->base_addr + field_offset(field))

struct mipsnet_priv {
	struct net_device_stats stats;
};

static struct platform_device *mips_plat_dev;

static char mipsnet_string[] = "mipsnet";

/*
 * Copy data from the MIPSNET rx data port
 */
static int ioiocpy_frommipsnet(struct net_device *dev, unsigned char *kdata,
			int len)
{
	uint32_t available_len = inl(mipsnet_reg_address(dev, rxDataCount));
	if (available_len < len)
		return -EFAULT;

	for (; len > 0; len--, kdata++) {
		*kdata = inb(mipsnet_reg_address(dev, rxDataBuffer));
	}

	return inl(mipsnet_reg_address(dev, rxDataCount));
}

static inline ssize_t mipsnet_put_todevice(struct net_device *dev,
	struct sk_buff *skb)
{
	int count_to_go = skb->len;
	char *buf_ptr = skb->data;
	struct mipsnet_priv *mp = netdev_priv(dev);

	pr_debug("%s: %s(): telling MIPSNET txDataCount(%d)\n",
	         dev->name, __FUNCTION__, skb->len);

	outl(skb->len, mipsnet_reg_address(dev, txDataCount));

	pr_debug("%s: %s(): sending data to MIPSNET txDataBuffer(%d)\n",
	         dev->name, __FUNCTION__, skb->len);

	for (; count_to_go; buf_ptr++, count_to_go--) {
		outb(*buf_ptr, mipsnet_reg_address(dev, txDataBuffer));
	}

	mp->stats.tx_packets++;
	mp->stats.tx_bytes += skb->len;

	return skb->len;
}

static int mipsnet_xmit(struct sk_buff *skb, struct net_device *dev)
{
	pr_debug("%s:%s(): transmitting %d bytes\n",
	         dev->name, __FUNCTION__, skb->len);

	/* Only one packet at a time. Once TXDONE interrupt is serviced, the
	 * queue will be restarted.
	 */
	netif_stop_queue(dev);
	mipsnet_put_todevice(dev, skb);

	return 0;
}

static inline ssize_t mipsnet_get_fromdev(struct net_device *dev, size_t count)
{
	struct sk_buff *skb;
	size_t len = count;
	struct mipsnet_priv *mp = netdev_priv(dev);

	if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
		mp->stats.rx_dropped++;
		return -ENOMEM;
	}

	skb_reserve(skb, 2);
	if (ioiocpy_frommipsnet(dev, skb_put(skb, len), len))
		return -EFAULT;

	skb->dev = dev;
	skb->protocol = eth_type_trans(skb, dev);
	skb->ip_summed = CHECKSUM_UNNECESSARY;

	pr_debug("%s:%s(): pushing RXed data to kernel\n",
	         dev->name, __FUNCTION__);
	netif_rx(skb);

	mp->stats.rx_packets++;
	mp->stats.rx_bytes += len;

	return count;
}

static irqreturn_t
mipsnet_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;

	irqreturn_t retval = IRQ_NONE;
	uint64_t interruptFlags;

	if (irq == dev->irq) {
		pr_debug("%s:%s(): irq %d for device\n",
		         dev->name, __FUNCTION__, irq);

		retval = IRQ_HANDLED;

		interruptFlags =
		    inl(mipsnet_reg_address(dev, interruptControl));
		pr_debug("%s:%s(): intCtl=0x%016llx\n", dev->name,
		         __FUNCTION__, interruptFlags);

		if (interruptFlags & MIPSNET_INTCTL_TXDONE) {
			pr_debug("%s:%s(): got TXDone\n",
			         dev->name, __FUNCTION__);
			outl(MIPSNET_INTCTL_TXDONE,
			     mipsnet_reg_address(dev, interruptControl));
			// only one packet at a time, we are done.
			netif_wake_queue(dev);
		} else if (interruptFlags & MIPSNET_INTCTL_RXDONE) {
			pr_debug("%s:%s(): got RX data\n",
			         dev->name, __FUNCTION__);
			mipsnet_get_fromdev(dev,
			            inl(mipsnet_reg_address(dev, rxDataCount)));
			pr_debug("%s:%s(): clearing RX int\n",
			         dev->name, __FUNCTION__);
			outl(MIPSNET_INTCTL_RXDONE,
			     mipsnet_reg_address(dev, interruptControl));

		} else if (interruptFlags & MIPSNET_INTCTL_TESTBIT) {
			pr_debug("%s:%s(): got test interrupt\n",
			         dev->name, __FUNCTION__);
			// TESTBIT is cleared on read.
			//    And takes effect after a write with 0
			outl(0, mipsnet_reg_address(dev, interruptControl));
		} else {
			pr_debug("%s:%s(): no valid fags 0x%016llx\n",
			         dev->name, __FUNCTION__, interruptFlags);
			// Maybe shared IRQ, just ignore, no clearing.
			retval = IRQ_NONE;
		}

	} else {
		printk(KERN_INFO "%s: %s(): irq %d for unknown device\n",
		       dev->name, __FUNCTION__, irq);
		retval = IRQ_NONE;
	}
	return retval;
}				//mipsnet_interrupt()

static int mipsnet_open(struct net_device *dev)
{
	int err;
	pr_debug("%s: mipsnet_open\n", dev->name);

	err = request_irq(dev->irq, &mipsnet_interrupt,
			  SA_SHIRQ, dev->name, (void *) dev);

	if (err) {
		pr_debug("%s: %s(): can't get irq %d\n",
		         dev->name, __FUNCTION__, dev->irq);
		release_region(dev->base_addr, MIPSNET_IO_EXTENT);
		return err;
	}

	pr_debug("%s: %s(): got IO region at 0x%04lx and irq %d for dev.\n",
	         dev->name, __FUNCTION__, dev->base_addr, dev->irq);


	netif_start_queue(dev);

	// test interrupt handler
	outl(MIPSNET_INTCTL_TESTBIT,
	     mipsnet_reg_address(dev, interruptControl));


	return 0;
}

static int mipsnet_close(struct net_device *dev)
{
	pr_debug("%s: %s()\n", dev->name, __FUNCTION__);
	netif_stop_queue(dev);
	return 0;
}

static struct net_device_stats *mipsnet_get_stats(struct net_device *dev)
{
	struct mipsnet_priv *mp = netdev_priv(dev);

	return &mp->stats;
}

static void mipsnet_set_mclist(struct net_device *dev)
{
	// we don't do anything
	return;
}

static int __init mipsnet_probe(struct device *dev)
{
	struct net_device *netdev;
	int err;

	netdev = alloc_etherdev(sizeof(struct mipsnet_priv));
	if (!netdev) {
		err = -ENOMEM;
		goto out;
	}

	dev_set_drvdata(dev, netdev);

	netdev->open			= mipsnet_open;
	netdev->stop			= mipsnet_close;
	netdev->hard_start_xmit		= mipsnet_xmit;
	netdev->get_stats		= mipsnet_get_stats;
	netdev->set_multicast_list	= mipsnet_set_mclist;

	/*
	 * TODO: probe for these or load them from PARAM
	 */
	netdev->base_addr = 0x4200;
	netdev->irq = MIPSCPU_INT_BASE + MIPSCPU_INT_MB0 +
	              inl(mipsnet_reg_address(netdev, interruptInfo));

	// Get the io region now, get irq on open()
	if (!request_region(netdev->base_addr, MIPSNET_IO_EXTENT, "mipsnet")) {
		pr_debug("%s: %s(): IO region {start: 0x%04lux, len: %d} "
		         "for dev is not availble.\n", netdev->name,
		         __FUNCTION__, netdev->base_addr, MIPSNET_IO_EXTENT);
		err = -EBUSY;
		goto out_free_netdev;
	}

	/*
	 * Lacking any better mechanism to allocate a MAC address we use a
	 * random one ...
	 */
	random_ether_addr(netdev->dev_addr);

	err = register_netdev(netdev);
	if (err) {
		printk(KERN_ERR "MIPSNet: failed to register netdev.\n");
		goto out_free_region;
	}

	return 0;

out_free_region:
	release_region(netdev->base_addr, MIPSNET_IO_EXTENT);

out_free_netdev:
	free_netdev(netdev);

out:
	return err;
}

static int __devexit mipsnet_device_remove(struct device *device)
{
	struct net_device *dev = dev_get_drvdata(device);

	unregister_netdev(dev);
	release_region(dev->base_addr, MIPSNET_IO_EXTENT);
	free_netdev(dev);
	dev_set_drvdata(device, NULL);

	return 0;
}

static struct device_driver mipsnet_driver = {
	.name	= mipsnet_string,
	.bus	= &platform_bus_type,
	.probe	= mipsnet_probe,
	.remove	= __devexit_p(mipsnet_device_remove),
};

static void mipsnet_platform_release(struct device *device)
{
	struct platform_device *pldev;

	/* free device */
	pldev = to_platform_device(device);
	kfree(pldev);
}

static int __init mipsnet_init_module(void)
{
	struct platform_device *pldev;
	int err;

	printk(KERN_INFO "MIPSNet Ethernet driver. Version: %s. "
	       "(c)2005 MIPS Technologies, Inc.\n", MIPSNET_VERSION);

	if (driver_register(&mipsnet_driver)) {
		printk(KERN_ERR "Driver registration failed\n");
		err = -ENODEV;
		goto out;
	}

        if (!(pldev = kmalloc (sizeof (*pldev), GFP_KERNEL))) {
		err = -ENOMEM;
		goto out_unregister_driver;
	}

	memset (pldev, 0, sizeof (*pldev));
	pldev->name		= mipsnet_string;
	pldev->id		= 0;
	pldev->dev.release	= mipsnet_platform_release;

	if (platform_device_register(pldev)) {
		err = -ENODEV;
		goto out_free_pldev;
	}

        if (!pldev->dev.driver) {
		/*
		 * The driver was not bound to this device, there was
                 * no hardware at this address. Unregister it, as the
		 * release fuction will take care of freeing the
		 * allocated structure
		 */
		platform_device_unregister (pldev);
	}

	mips_plat_dev		= pldev;

	return 0;

out_free_pldev:
	kfree(pldev);

out_unregister_driver:
	driver_unregister(&mipsnet_driver);
out:
	return err;
}

static void __exit mipsnet_exit_module(void)
{
	pr_debug("MIPSNet Ethernet driver exiting\n");

	driver_unregister(&mipsnet_driver);
}

module_init(mipsnet_init_module);
module_exit(mipsnet_exit_module);