1 /*
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>
9 #include <linux/sched.h>
10 #include <linux/spinlock.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>
19
20 struct preg {
21 unsigned char r;
22 char pad[15];
23 };
24
25 struct adb_regs {
26 struct preg intr;
27 struct preg data[9];
28 struct preg intr_enb;
29 struct preg dcount;
30 struct preg error;
31 struct preg ctrl;
32 struct preg autopoll;
33 struct preg active_hi;
34 struct preg active_lo;
35 struct preg test;
36 };
37
38 /* Bits in intr and intr_enb registers */
39 #define DFB 1 /* data from bus */
40 #define TAG 2 /* transfer access grant */
41
42 /* Bits in dcount register */
43 #define HMB 0x0f /* how many bytes */
44 #define APD 0x10 /* auto-poll data */
45
46 /* Bits in error register */
47 #define NRE 1 /* no response error */
48 #define DLE 2 /* data lost error */
49
50 /* Bits in ctrl register */
51 #define TAR 1 /* transfer access request */
52 #define DTB 2 /* data to bus */
53 #define CRE 4 /* command response expected */
54 #define ADB_RST 8 /* ADB reset */
55
56 /* Bits in autopoll register */
57 #define APE 1 /* autopoll enable */
58
59 static volatile struct adb_regs *adb;
60 static struct adb_request *current_req, *last_req;
61 static spinlock_t macio_lock = SPIN_LOCK_UNLOCKED;
62
63 static int macio_probe(void);
64 static int macio_init(void);
65 static void macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs);
66 static int macio_send_request(struct adb_request *req, int sync);
67 static int macio_adb_autopoll(int devs);
68 static void macio_adb_poll(void);
69 static int macio_adb_reset_bus(void);
70
71 struct adb_driver macio_adb_driver = {
72 "MACIO",
73 macio_probe,
74 macio_init,
75 macio_send_request,
76 /*macio_write,*/
77 macio_adb_autopoll,
78 macio_adb_poll,
79 macio_adb_reset_bus
80 };
81
macio_probe(void)82 int macio_probe(void)
83 {
84 return find_compatible_devices("adb", "chrp,adb0")? 0: -ENODEV;
85 }
86
macio_init(void)87 int macio_init(void)
88 {
89 struct device_node *adbs;
90
91 adbs = find_compatible_devices("adb", "chrp,adb0");
92 if (adbs == 0)
93 return -ENXIO;
94
95 #if 0
96 { int i;
97
98 printk("macio_adb_init: node = %p, addrs =", adbs->node);
99 for (i = 0; i < adbs->n_addrs; ++i)
100 printk(" %x(%x)", adbs->addrs[i].address, adbs->addrs[i].size);
101 printk(", intrs =");
102 for (i = 0; i < adbs->n_intrs; ++i)
103 printk(" %x", adbs->intrs[i].line);
104 printk("\n"); }
105 #endif
106
107 adb = (volatile struct adb_regs *)
108 ioremap(adbs->addrs->address, sizeof(struct adb_regs));
109
110 out_8(&adb->ctrl.r, 0);
111 out_8(&adb->intr.r, 0);
112 out_8(&adb->error.r, 0);
113 out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */
114 out_8(&adb->active_lo.r, 0xff);
115 out_8(&adb->autopoll.r, APE);
116
117 if (request_irq(adbs->intrs[0].line, macio_adb_interrupt,
118 0, "ADB", (void *)0)) {
119 printk(KERN_ERR "ADB: can't get irq %d\n",
120 adbs->intrs[0].line);
121 return -EAGAIN;
122 }
123 out_8(&adb->intr_enb.r, DFB | TAG);
124
125 printk("adb: mac-io driver 1.0 for unified ADB\n");
126
127 return 0;
128 }
129
macio_adb_autopoll(int devs)130 static int macio_adb_autopoll(int devs)
131 {
132 unsigned long flags;
133
134 spin_lock_irqsave(&macio_lock, flags);
135 out_8(&adb->active_hi.r, devs >> 8);
136 out_8(&adb->active_lo.r, devs);
137 out_8(&adb->autopoll.r, devs? APE: 0);
138 spin_unlock_irqrestore(&macio_lock, flags);
139 return 0;
140 }
141
macio_adb_reset_bus(void)142 static int macio_adb_reset_bus(void)
143 {
144 unsigned long flags;
145 int timeout = 1000000;
146
147 /* Hrm... we may want to not lock interrupts for so
148 * long ... oh well, who uses that chip anyway ? :)
149 * That function will be seldomly used during boot
150 * on rare machines, so...
151 */
152 spin_lock_irqsave(&macio_lock, flags);
153 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST);
154 while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
155 if (--timeout == 0) {
156 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
157 return -1;
158 }
159 }
160 spin_unlock_irqrestore(&macio_lock, flags);
161 return 0;
162 }
163
164 /* Send an ADB command */
macio_send_request(struct adb_request * req,int sync)165 static int macio_send_request(struct adb_request *req, int sync)
166 {
167 unsigned long flags;
168 int i;
169
170 if (req->data[0] != ADB_PACKET)
171 return -EINVAL;
172
173 for (i = 0; i < req->nbytes - 1; ++i)
174 req->data[i] = req->data[i+1];
175 --req->nbytes;
176
177 req->next = 0;
178 req->sent = 0;
179 req->complete = 0;
180 req->reply_len = 0;
181
182 spin_lock_irqsave(&macio_lock, flags);
183 if (current_req != 0) {
184 last_req->next = req;
185 last_req = req;
186 } else {
187 current_req = last_req = req;
188 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
189 }
190 spin_unlock_irqrestore(&macio_lock, flags);
191
192 if (sync) {
193 while (!req->complete)
194 macio_adb_poll();
195 }
196
197 return 0;
198 }
199
macio_adb_interrupt(int irq,void * arg,struct pt_regs * regs)200 static void macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs)
201 {
202 int i, n, err;
203 struct adb_request *req;
204 unsigned char ibuf[16];
205 int ibuf_len = 0;
206 int complete = 0;
207 int autopoll = 0;
208
209 spin_lock(&macio_lock);
210 if (in_8(&adb->intr.r) & TAG) {
211 if ((req = current_req) != 0) {
212 /* put the current request in */
213 for (i = 0; i < req->nbytes; ++i)
214 out_8(&adb->data[i].r, req->data[i]);
215 out_8(&adb->dcount.r, req->nbytes & HMB);
216 req->sent = 1;
217 if (req->reply_expected) {
218 out_8(&adb->ctrl.r, DTB + CRE);
219 } else {
220 out_8(&adb->ctrl.r, DTB);
221 current_req = req->next;
222 complete = 1;
223 if (current_req)
224 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
225 }
226 }
227 out_8(&adb->intr.r, 0);
228 }
229
230 if (in_8(&adb->intr.r) & DFB) {
231 err = in_8(&adb->error.r);
232 if (current_req && current_req->sent) {
233 /* this is the response to a command */
234 req = current_req;
235 if (err == 0) {
236 req->reply_len = in_8(&adb->dcount.r) & HMB;
237 for (i = 0; i < req->reply_len; ++i)
238 req->reply[i] = in_8(&adb->data[i].r);
239 }
240 current_req = req->next;
241 complete = 1;
242 if (current_req)
243 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
244 } else if (err == 0) {
245 /* autopoll data */
246 n = in_8(&adb->dcount.r) & HMB;
247 for (i = 0; i < n; ++i)
248 ibuf[i] = in_8(&adb->data[i].r);
249 ibuf_len = n;
250 autopoll = (in_8(&adb->dcount.r) & APD) != 0;
251 }
252 out_8(&adb->error.r, 0);
253 out_8(&adb->intr.r, 0);
254 }
255 spin_unlock(&macio_lock);
256 if (complete && req) {
257 void (*done)(struct adb_request *) = req->done;
258 mb();
259 req->complete = 1;
260 /* Here, we assume that if the request has a done member, the
261 * struct request will survive to setting req->complete to 1
262 */
263 if (done)
264 (*done)(req);
265 }
266 if (ibuf_len)
267 adb_input(ibuf, ibuf_len, regs, autopoll);
268 }
269
macio_adb_poll(void)270 static void macio_adb_poll(void)
271 {
272 unsigned long flags;
273
274 local_irq_save(flags);
275 if (in_8(&adb->intr.r) != 0)
276 macio_adb_interrupt(0, 0, 0);
277 local_irq_restore(flags);
278 }
279