1/*
2 * atari_nfeth.c - ARAnyM ethernet card driver for GNU/Linux
3 *
4 * Copyright (c) 2005 Milan Jurik, Petr Stehlik of ARAnyM dev team
5 *
6 * Based on ARAnyM driver for FreeMiNT written by Standa Opichal
7 *
8 * This software may be used and distributed according to the terms of
9 * the GNU General Public License (GPL), incorporated herein by reference.
10 */
11
12#define DRV_VERSION	"0.3"
13#define DRV_RELDATE	"10/12/2005"
14
15#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
16
17#include <linux/netdevice.h>
18#include <linux/etherdevice.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <asm/natfeat.h>
22#include <asm/virtconvert.h>
23
24enum {
25	GET_VERSION = 0,/* no parameters, return NFAPI_VERSION in d0 */
26	XIF_INTLEVEL,	/* no parameters, return Interrupt Level in d0 */
27	XIF_IRQ,	/* acknowledge interrupt from host */
28	XIF_START,	/* (ethX), called on 'ifup', start receiver thread */
29	XIF_STOP,	/* (ethX), called on 'ifdown', stop the thread */
30	XIF_READLENGTH,	/* (ethX), return size of network data block to read */
31	XIF_READBLOCK,	/* (ethX, buffer, size), read block of network data */
32	XIF_WRITEBLOCK,	/* (ethX, buffer, size), write block of network data */
33	XIF_GET_MAC,	/* (ethX, buffer, size), return MAC HW addr in buffer */
34	XIF_GET_IPHOST,	/* (ethX, buffer, size), return IP address of host */
35	XIF_GET_IPATARI,/* (ethX, buffer, size), return IP address of atari */
36	XIF_GET_NETMASK	/* (ethX, buffer, size), return IP netmask */
37};
38
39#define MAX_UNIT	8
40
41/* These identify the driver base version and may not be removed. */
42static const char version[] =
43	KERN_INFO KBUILD_MODNAME ".c:v" DRV_VERSION " " DRV_RELDATE
44	" S.Opichal, M.Jurik, P.Stehlik\n"
45	KERN_INFO " http://aranym.org/\n";
46
47MODULE_AUTHOR("Milan Jurik");
48MODULE_DESCRIPTION("Atari NFeth driver");
49MODULE_LICENSE("GPL");
50/*
51MODULE_PARM(nfeth_debug, "i");
52MODULE_PARM_DESC(nfeth_debug, "nfeth_debug level (1-2)");
53*/
54
55
56static long nfEtherID;
57static int nfEtherIRQ;
58
59struct nfeth_private {
60	int ethX;
61};
62
63static struct net_device *nfeth_dev[MAX_UNIT];
64
65static int nfeth_open(struct net_device *dev)
66{
67	struct nfeth_private *priv = netdev_priv(dev);
68	int res;
69
70	res = nf_call(nfEtherID + XIF_START, priv->ethX);
71	netdev_dbg(dev, "%s: %d\n", __func__, res);
72
73	/* Ready for data */
74	netif_start_queue(dev);
75
76	return 0;
77}
78
79static int nfeth_stop(struct net_device *dev)
80{
81	struct nfeth_private *priv = netdev_priv(dev);
82
83	/* No more data */
84	netif_stop_queue(dev);
85
86	nf_call(nfEtherID + XIF_STOP, priv->ethX);
87
88	return 0;
89}
90
91/*
92 * Read a packet out of the adapter and pass it to the upper layers
93 */
94static inline void recv_packet(struct net_device *dev)
95{
96	struct nfeth_private *priv = netdev_priv(dev);
97	unsigned short pktlen;
98	struct sk_buff *skb;
99
100	/* read packet length (excluding 32 bit crc) */
101	pktlen = nf_call(nfEtherID + XIF_READLENGTH, priv->ethX);
102
103	netdev_dbg(dev, "%s: %u\n", __func__, pktlen);
104
105	if (!pktlen) {
106		netdev_dbg(dev, "%s: pktlen == 0\n", __func__);
107		dev->stats.rx_errors++;
108		return;
109	}
110
111	skb = dev_alloc_skb(pktlen + 2);
112	if (!skb) {
113		netdev_dbg(dev, "%s: out of mem (buf_alloc failed)\n",
114			   __func__);
115		dev->stats.rx_dropped++;
116		return;
117	}
118
119	skb->dev = dev;
120	skb_reserve(skb, 2);		/* 16 Byte align  */
121	skb_put(skb, pktlen);		/* make room */
122	nf_call(nfEtherID + XIF_READBLOCK, priv->ethX, virt_to_phys(skb->data),
123		pktlen);
124
125	skb->protocol = eth_type_trans(skb, dev);
126	netif_rx(skb);
127	dev->last_rx = jiffies;
128	dev->stats.rx_packets++;
129	dev->stats.rx_bytes += pktlen;
130
131	/* and enqueue packet */
132	return;
133}
134
135static irqreturn_t nfeth_interrupt(int irq, void *dev_id)
136{
137	int i, m, mask;
138
139	mask = nf_call(nfEtherID + XIF_IRQ, 0);
140	for (i = 0, m = 1; i < MAX_UNIT; m <<= 1, i++) {
141		if (mask & m && nfeth_dev[i]) {
142			recv_packet(nfeth_dev[i]);
143			nf_call(nfEtherID + XIF_IRQ, m);
144		}
145	}
146	return IRQ_HANDLED;
147}
148
149static int nfeth_xmit(struct sk_buff *skb, struct net_device *dev)
150{
151	unsigned int len;
152	char *data, shortpkt[ETH_ZLEN];
153	struct nfeth_private *priv = netdev_priv(dev);
154
155	data = skb->data;
156	len = skb->len;
157	if (len < ETH_ZLEN) {
158		memset(shortpkt, 0, ETH_ZLEN);
159		memcpy(shortpkt, data, len);
160		data = shortpkt;
161		len = ETH_ZLEN;
162	}
163
164	netdev_dbg(dev, "%s: send %u bytes\n", __func__, len);
165	nf_call(nfEtherID + XIF_WRITEBLOCK, priv->ethX, virt_to_phys(data),
166		len);
167
168	dev->stats.tx_packets++;
169	dev->stats.tx_bytes += len;
170
171	dev_kfree_skb(skb);
172	return 0;
173}
174
175static void nfeth_tx_timeout(struct net_device *dev)
176{
177	dev->stats.tx_errors++;
178	netif_wake_queue(dev);
179}
180
181static const struct net_device_ops nfeth_netdev_ops = {
182	.ndo_open		= nfeth_open,
183	.ndo_stop		= nfeth_stop,
184	.ndo_start_xmit		= nfeth_xmit,
185	.ndo_tx_timeout		= nfeth_tx_timeout,
186	.ndo_validate_addr	= eth_validate_addr,
187	.ndo_change_mtu		= eth_change_mtu,
188	.ndo_set_mac_address	= eth_mac_addr,
189};
190
191static struct net_device * __init nfeth_probe(int unit)
192{
193	struct net_device *dev;
194	struct nfeth_private *priv;
195	char mac[ETH_ALEN], host_ip[32], local_ip[32];
196	int err;
197
198	if (!nf_call(nfEtherID + XIF_GET_MAC, unit, virt_to_phys(mac),
199		     ETH_ALEN))
200		return NULL;
201
202	dev = alloc_etherdev(sizeof(struct nfeth_private));
203	if (!dev)
204		return NULL;
205
206	dev->irq = nfEtherIRQ;
207	dev->netdev_ops = &nfeth_netdev_ops;
208
209	memcpy(dev->dev_addr, mac, ETH_ALEN);
210
211	priv = netdev_priv(dev);
212	priv->ethX = unit;
213
214	err = register_netdev(dev);
215	if (err) {
216		free_netdev(dev);
217		return NULL;
218	}
219
220	nf_call(nfEtherID + XIF_GET_IPHOST, unit,
221		virt_to_phys(host_ip), sizeof(host_ip));
222	nf_call(nfEtherID + XIF_GET_IPATARI, unit,
223		virt_to_phys(local_ip), sizeof(local_ip));
224
225	netdev_info(dev, KBUILD_MODNAME " addr:%s (%s) HWaddr:%pM\n", host_ip,
226		    local_ip, mac);
227
228	return dev;
229}
230
231static int __init nfeth_init(void)
232{
233	long ver;
234	int error, i;
235
236	nfEtherID = nf_get_id("ETHERNET");
237	if (!nfEtherID)
238		return -ENODEV;
239
240	ver = nf_call(nfEtherID + GET_VERSION);
241	pr_info("API %lu\n", ver);
242
243	nfEtherIRQ = nf_call(nfEtherID + XIF_INTLEVEL);
244	error = request_irq(nfEtherIRQ, nfeth_interrupt, IRQF_SHARED,
245			    "eth emu", nfeth_interrupt);
246	if (error) {
247		pr_err("request for irq %d failed %d", nfEtherIRQ, error);
248		return error;
249	}
250
251	for (i = 0; i < MAX_UNIT; i++)
252		nfeth_dev[i] = nfeth_probe(i);
253
254	return 0;
255}
256
257static void __exit nfeth_cleanup(void)
258{
259	int i;
260
261	for (i = 0; i < MAX_UNIT; i++) {
262		if (nfeth_dev[i]) {
263			unregister_netdev(nfeth_dev[0]);
264			free_netdev(nfeth_dev[0]);
265		}
266	}
267	free_irq(nfEtherIRQ, nfeth_interrupt);
268}
269
270module_init(nfeth_init);
271module_exit(nfeth_cleanup);
272