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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Driver for the ADB controller in the Mac I/O (Hydra) chip.
3 */
4#include <stdarg.h>
5#include <linux/types.h>
6#include <linux/errno.h>
7#include <linux/kernel.h>
8#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/spinlock.h>
10#include <linux/interrupt.h>
11#include <asm/prom.h>
12#include <linux/adb.h>
13#include <asm/io.h>
14#include <asm/pgtable.h>
15#include <asm/hydra.h>
16#include <asm/irq.h>
17#include <asm/system.h>
18#include <linux/init.h>
David Woodhouse36874572006-01-14 00:15:19 +000019#include <linux/ioport.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21struct preg {
22 unsigned char r;
23 char pad[15];
24};
25
26struct adb_regs {
27 struct preg intr;
28 struct preg data[9];
29 struct preg intr_enb;
30 struct preg dcount;
31 struct preg error;
32 struct preg ctrl;
33 struct preg autopoll;
34 struct preg active_hi;
35 struct preg active_lo;
36 struct preg test;
37};
38
39/* Bits in intr and intr_enb registers */
40#define DFB 1 /* data from bus */
41#define TAG 2 /* transfer access grant */
42
43/* Bits in dcount register */
44#define HMB 0x0f /* how many bytes */
45#define APD 0x10 /* auto-poll data */
46
47/* Bits in error register */
48#define NRE 1 /* no response error */
49#define DLE 2 /* data lost error */
50
51/* Bits in ctrl register */
52#define TAR 1 /* transfer access request */
53#define DTB 2 /* data to bus */
54#define CRE 4 /* command response expected */
55#define ADB_RST 8 /* ADB reset */
56
57/* Bits in autopoll register */
58#define APE 1 /* autopoll enable */
59
60static volatile struct adb_regs __iomem *adb;
61static struct adb_request *current_req, *last_req;
62static DEFINE_SPINLOCK(macio_lock);
63
64static int macio_probe(void);
65static int macio_init(void);
David Howells7d12e782006-10-05 14:55:46 +010066static irqreturn_t macio_adb_interrupt(int irq, void *arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067static int macio_send_request(struct adb_request *req, int sync);
68static int macio_adb_autopoll(int devs);
69static void macio_adb_poll(void);
70static int macio_adb_reset_bus(void);
71
72struct adb_driver macio_adb_driver = {
73 "MACIO",
74 macio_probe,
75 macio_init,
76 macio_send_request,
77 /*macio_write,*/
78 macio_adb_autopoll,
79 macio_adb_poll,
80 macio_adb_reset_bus
81};
82
83int macio_probe(void)
84{
Stephen Rothwell4bf56e12007-04-24 13:48:41 +100085 struct device_node *np;
86
87 np = of_find_compatible_node(NULL, "adb", "chrp,adb0");
88 if (np) {
89 of_node_put(np);
90 return 0;
91 }
92 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
95int macio_init(void)
96{
97 struct device_node *adbs;
David Woodhouse36874572006-01-14 00:15:19 +000098 struct resource r;
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100099 unsigned int irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Stephen Rothwell4bf56e12007-04-24 13:48:41 +1000101 adbs = of_find_compatible_node(NULL, "adb", "chrp,adb0");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 if (adbs == 0)
103 return -ENXIO;
104
Stephen Rothwell4bf56e12007-04-24 13:48:41 +1000105 if (of_address_to_resource(adbs, 0, &r)) {
106 of_node_put(adbs);
David Woodhouse36874572006-01-14 00:15:19 +0000107 return -ENXIO;
Stephen Rothwell4bf56e12007-04-24 13:48:41 +1000108 }
David Woodhouse36874572006-01-14 00:15:19 +0000109 adb = ioremap(r.start, sizeof(struct adb_regs));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111 out_8(&adb->ctrl.r, 0);
112 out_8(&adb->intr.r, 0);
113 out_8(&adb->error.r, 0);
114 out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */
115 out_8(&adb->active_lo.r, 0xff);
116 out_8(&adb->autopoll.r, APE);
117
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000118 irq = irq_of_parse_and_map(adbs, 0);
Stephen Rothwell4bf56e12007-04-24 13:48:41 +1000119 of_node_put(adbs);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000120 if (request_irq(irq, macio_adb_interrupt, 0, "ADB", (void *)0)) {
121 printk(KERN_ERR "ADB: can't get irq %d\n", irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 return -EAGAIN;
123 }
124 out_8(&adb->intr_enb.r, DFB | TAG);
125
126 printk("adb: mac-io driver 1.0 for unified ADB\n");
127
128 return 0;
129}
130
131static int macio_adb_autopoll(int devs)
132{
133 unsigned long flags;
134
135 spin_lock_irqsave(&macio_lock, flags);
136 out_8(&adb->active_hi.r, devs >> 8);
137 out_8(&adb->active_lo.r, devs);
138 out_8(&adb->autopoll.r, devs? APE: 0);
139 spin_unlock_irqrestore(&macio_lock, flags);
140 return 0;
141}
142
143static int macio_adb_reset_bus(void)
144{
145 unsigned long flags;
146 int timeout = 1000000;
147
148 /* Hrm... we may want to not lock interrupts for so
149 * long ... oh well, who uses that chip anyway ? :)
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300150 * That function will be seldom used during boot
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 * on rare machines, so...
152 */
153 spin_lock_irqsave(&macio_lock, flags);
154 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST);
155 while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
156 if (--timeout == 0) {
157 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
Julia Lawall86e47542010-03-29 05:34:46 +0000158 spin_unlock_irqrestore(&macio_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 return -1;
160 }
161 }
162 spin_unlock_irqrestore(&macio_lock, flags);
163 return 0;
164}
165
166/* Send an ADB command */
167static int macio_send_request(struct adb_request *req, int sync)
168{
169 unsigned long flags;
170 int i;
171
172 if (req->data[0] != ADB_PACKET)
173 return -EINVAL;
174
175 for (i = 0; i < req->nbytes - 1; ++i)
176 req->data[i] = req->data[i+1];
177 --req->nbytes;
178
179 req->next = NULL;
180 req->sent = 0;
181 req->complete = 0;
182 req->reply_len = 0;
183
184 spin_lock_irqsave(&macio_lock, flags);
185 if (current_req != 0) {
186 last_req->next = req;
187 last_req = req;
188 } else {
189 current_req = last_req = req;
190 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
191 }
192 spin_unlock_irqrestore(&macio_lock, flags);
193
194 if (sync) {
195 while (!req->complete)
196 macio_adb_poll();
197 }
198
199 return 0;
200}
201
David Howells7d12e782006-10-05 14:55:46 +0100202static irqreturn_t macio_adb_interrupt(int irq, void *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
204 int i, n, err;
205 struct adb_request *req = NULL;
206 unsigned char ibuf[16];
207 int ibuf_len = 0;
208 int complete = 0;
209 int autopoll = 0;
210 int handled = 0;
211
212 spin_lock(&macio_lock);
213 if (in_8(&adb->intr.r) & TAG) {
214 handled = 1;
215 if ((req = current_req) != 0) {
216 /* put the current request in */
217 for (i = 0; i < req->nbytes; ++i)
218 out_8(&adb->data[i].r, req->data[i]);
219 out_8(&adb->dcount.r, req->nbytes & HMB);
220 req->sent = 1;
221 if (req->reply_expected) {
222 out_8(&adb->ctrl.r, DTB + CRE);
223 } else {
224 out_8(&adb->ctrl.r, DTB);
225 current_req = req->next;
226 complete = 1;
227 if (current_req)
228 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
229 }
230 }
231 out_8(&adb->intr.r, 0);
232 }
233
234 if (in_8(&adb->intr.r) & DFB) {
235 handled = 1;
236 err = in_8(&adb->error.r);
237 if (current_req && current_req->sent) {
238 /* this is the response to a command */
239 req = current_req;
240 if (err == 0) {
241 req->reply_len = in_8(&adb->dcount.r) & HMB;
242 for (i = 0; i < req->reply_len; ++i)
243 req->reply[i] = in_8(&adb->data[i].r);
244 }
245 current_req = req->next;
246 complete = 1;
247 if (current_req)
248 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
249 } else if (err == 0) {
250 /* autopoll data */
251 n = in_8(&adb->dcount.r) & HMB;
252 for (i = 0; i < n; ++i)
253 ibuf[i] = in_8(&adb->data[i].r);
254 ibuf_len = n;
255 autopoll = (in_8(&adb->dcount.r) & APD) != 0;
256 }
257 out_8(&adb->error.r, 0);
258 out_8(&adb->intr.r, 0);
259 }
260 spin_unlock(&macio_lock);
261 if (complete && req) {
262 void (*done)(struct adb_request *) = req->done;
263 mb();
264 req->complete = 1;
265 /* Here, we assume that if the request has a done member, the
266 * struct request will survive to setting req->complete to 1
267 */
268 if (done)
269 (*done)(req);
270 }
271 if (ibuf_len)
David Howells7d12e782006-10-05 14:55:46 +0100272 adb_input(ibuf, ibuf_len, autopoll);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 return IRQ_RETVAL(handled);
275}
276
277static void macio_adb_poll(void)
278{
279 unsigned long flags;
280
281 local_irq_save(flags);
282 if (in_8(&adb->intr.r) != 0)
Al Viro9da3b1a2006-10-08 15:00:44 +0100283 macio_adb_interrupt(0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 local_irq_restore(flags);
285}