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[] __maybe_unused =
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
51
52static long nfEtherID;
53static int nfEtherIRQ;
54
55struct nfeth_private {
56	int ethX;
57};
58
59static struct net_device *nfeth_dev[MAX_UNIT];
60
61static int nfeth_open(struct net_device *dev)
62{
63	struct nfeth_private *priv = netdev_priv(dev);
64	int res;
65
66	res = nf_call(nfEtherID + XIF_START, priv->ethX);
67	netdev_dbg(dev, "%s: %d\n", __func__, res);
68
69	/* Ready for data */
70	netif_start_queue(dev);
71
72	return 0;
73}
74
75static int nfeth_stop(struct net_device *dev)
76{
77	struct nfeth_private *priv = netdev_priv(dev);
78
79	/* No more data */
80	netif_stop_queue(dev);
81
82	nf_call(nfEtherID + XIF_STOP, priv->ethX);
83
84	return 0;
85}
86
87/*
88 * Read a packet out of the adapter and pass it to the upper layers
89 */
90static inline void recv_packet(struct net_device *dev)
91{
92	struct nfeth_private *priv = netdev_priv(dev);
93	unsigned short pktlen;
94	struct sk_buff *skb;
95
96	/* read packet length (excluding 32 bit crc) */
97	pktlen = nf_call(nfEtherID + XIF_READLENGTH, priv->ethX);
98
99	netdev_dbg(dev, "%s: %u\n", __func__, pktlen);
100
101	if (!pktlen) {
102		netdev_dbg(dev, "%s: pktlen == 0\n", __func__);
103		dev->stats.rx_errors++;
104		return;
105	}
106
107	skb = dev_alloc_skb(pktlen + 2);
108	if (!skb) {
109		netdev_dbg(dev, "%s: out of mem (buf_alloc failed)\n",
110			   __func__);
111		dev->stats.rx_dropped++;
112		return;
113	}
114
115	skb->dev = dev;
116	skb_reserve(skb, 2);		/* 16 Byte align  */
117	skb_put(skb, pktlen);		/* make room */
118	nf_call(nfEtherID + XIF_READBLOCK, priv->ethX, virt_to_phys(skb->data),
119		pktlen);
120
121	skb->protocol = eth_type_trans(skb, dev);
122	netif_rx(skb);
123	dev->stats.rx_packets++;
124	dev->stats.rx_bytes += pktlen;
125
126	/* and enqueue packet */
127	return;
128}
129
130static irqreturn_t nfeth_interrupt(int irq, void *dev_id)
131{
132	int i, m, mask;
133
134	mask = nf_call(nfEtherID + XIF_IRQ, 0);
135	for (i = 0, m = 1; i < MAX_UNIT; m <<= 1, i++) {
136		if (mask & m && nfeth_dev[i]) {
137			recv_packet(nfeth_dev[i]);
138			nf_call(nfEtherID + XIF_IRQ, m);
139		}
140	}
141	return IRQ_HANDLED;
142}
143
144static int nfeth_xmit(struct sk_buff *skb, struct net_device *dev)
145{
146	unsigned int len;
147	char *data, shortpkt[ETH_ZLEN];
148	struct nfeth_private *priv = netdev_priv(dev);
149
150	data = skb->data;
151	len = skb->len;
152	if (len < ETH_ZLEN) {
153		memset(shortpkt, 0, ETH_ZLEN);
154		memcpy(shortpkt, data, len);
155		data = shortpkt;
156		len = ETH_ZLEN;
157	}
158
159	netdev_dbg(dev, "%s: send %u bytes\n", __func__, len);
160	nf_call(nfEtherID + XIF_WRITEBLOCK, priv->ethX, virt_to_phys(data),
161		len);
162
163	dev->stats.tx_packets++;
164	dev->stats.tx_bytes += len;
165
166	dev_kfree_skb(skb);
167	return 0;
168}
169
170static void nfeth_tx_timeout(struct net_device *dev, unsigned int txqueue)
171{
172	dev->stats.tx_errors++;
173	netif_wake_queue(dev);
174}
175
176static const struct net_device_ops nfeth_netdev_ops = {
177	.ndo_open		= nfeth_open,
178	.ndo_stop		= nfeth_stop,
179	.ndo_start_xmit		= nfeth_xmit,
180	.ndo_tx_timeout		= nfeth_tx_timeout,
181	.ndo_validate_addr	= eth_validate_addr,
182	.ndo_set_mac_address	= eth_mac_addr,
183};
184
185static struct net_device * __init nfeth_probe(int unit)
186{
187	struct net_device *dev;
188	struct nfeth_private *priv;
189	char mac[ETH_ALEN], host_ip[32], local_ip[32];
190	int err;
191
192	if (!nf_call(nfEtherID + XIF_GET_MAC, unit, virt_to_phys(mac),
193		     ETH_ALEN))
194		return NULL;
195
196	dev = alloc_etherdev(sizeof(struct nfeth_private));
197	if (!dev)
198		return NULL;
199
200	dev->irq = nfEtherIRQ;
201	dev->netdev_ops = &nfeth_netdev_ops;
202
203	eth_hw_addr_set(dev, mac);
204
205	priv = netdev_priv(dev);
206	priv->ethX = unit;
207
208	err = register_netdev(dev);
209	if (err) {
210		free_netdev(dev);
211		return NULL;
212	}
213
214	nf_call(nfEtherID + XIF_GET_IPHOST, unit,
215		virt_to_phys(host_ip), sizeof(host_ip));
216	nf_call(nfEtherID + XIF_GET_IPATARI, unit,
217		virt_to_phys(local_ip), sizeof(local_ip));
218
219	netdev_info(dev, KBUILD_MODNAME " addr:%s (%s) HWaddr:%pM\n", host_ip,
220		    local_ip, mac);
221
222	return dev;
223}
224
225static int __init nfeth_init(void)
226{
227	long ver;
228	int error, i;
229
230	nfEtherID = nf_get_id("ETHERNET");
231	if (!nfEtherID)
232		return -ENODEV;
233
234	ver = nf_call(nfEtherID + GET_VERSION);
235	pr_info("API %lu\n", ver);
236
237	nfEtherIRQ = nf_call(nfEtherID + XIF_INTLEVEL);
238	error = request_irq(nfEtherIRQ, nfeth_interrupt, IRQF_SHARED,
239			    "eth emu", nfeth_interrupt);
240	if (error) {
241		pr_err("request for irq %d failed %d", nfEtherIRQ, error);
242		return error;
243	}
244
245	for (i = 0; i < MAX_UNIT; i++)
246		nfeth_dev[i] = nfeth_probe(i);
247
248	return 0;
249}
250
251static void __exit nfeth_cleanup(void)
252{
253	int i;
254
255	for (i = 0; i < MAX_UNIT; i++) {
256		if (nfeth_dev[i]) {
257			unregister_netdev(nfeth_dev[i]);
258			free_netdev(nfeth_dev[i]);
259		}
260	}
261	free_irq(nfEtherIRQ, nfeth_interrupt);
262}
263
264module_init(nfeth_init);
265module_exit(nfeth_cleanup);
266