tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 <linux/interrupt.h>
12#include <asm/prom.h>
13#include <linux/adb.h>
14#include <asm/io.h>
15#include <asm/pgtable.h>
16#include <asm/hydra.h>
17#include <asm/irq.h>
18#include <asm/system.h>
19#include <linux/init.h>
20
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);
66static irqreturn_t macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs);
67static 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{
85 return find_compatible_devices("adb", "chrp,adb0")? 0: -ENODEV;
86}
87
88int macio_init(void)
89{
90 struct device_node *adbs;
91
92 adbs = find_compatible_devices("adb", "chrp,adb0");
93 if (adbs == 0)
94 return -ENXIO;
95
96#if 0
97 { int i;
98
99 printk("macio_adb_init: node = %p, addrs =", adbs->node);
100 for (i = 0; i < adbs->n_addrs; ++i)
101 printk(" %x(%x)", adbs->addrs[i].address, adbs->addrs[i].size);
102 printk(", intrs =");
103 for (i = 0; i < adbs->n_intrs; ++i)
104 printk(" %x", adbs->intrs[i].line);
105 printk("\n"); }
106#endif
107
108 adb = 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
130static 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
142static 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 */
165static 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 = NULL;
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
200static irqreturn_t macio_adb_interrupt(int irq, void *arg,
201 struct pt_regs *regs)
202{
203 int i, n, err;
204 struct adb_request *req = NULL;
205 unsigned char ibuf[16];
206 int ibuf_len = 0;
207 int complete = 0;
208 int autopoll = 0;
209 int handled = 0;
210
211 spin_lock(&macio_lock);
212 if (in_8(&adb->intr.r) & TAG) {
213 handled = 1;
214 if ((req = current_req) != 0) {
215 /* put the current request in */
216 for (i = 0; i < req->nbytes; ++i)
217 out_8(&adb->data[i].r, req->data[i]);
218 out_8(&adb->dcount.r, req->nbytes & HMB);
219 req->sent = 1;
220 if (req->reply_expected) {
221 out_8(&adb->ctrl.r, DTB + CRE);
222 } else {
223 out_8(&adb->ctrl.r, DTB);
224 current_req = req->next;
225 complete = 1;
226 if (current_req)
227 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
228 }
229 }
230 out_8(&adb->intr.r, 0);
231 }
232
233 if (in_8(&adb->intr.r) & DFB) {
234 handled = 1;
235 err = in_8(&adb->error.r);
236 if (current_req && current_req->sent) {
237 /* this is the response to a command */
238 req = current_req;
239 if (err == 0) {
240 req->reply_len = in_8(&adb->dcount.r) & HMB;
241 for (i = 0; i < req->reply_len; ++i)
242 req->reply[i] = in_8(&adb->data[i].r);
243 }
244 current_req = req->next;
245 complete = 1;
246 if (current_req)
247 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
248 } else if (err == 0) {
249 /* autopoll data */
250 n = in_8(&adb->dcount.r) & HMB;
251 for (i = 0; i < n; ++i)
252 ibuf[i] = in_8(&adb->data[i].r);
253 ibuf_len = n;
254 autopoll = (in_8(&adb->dcount.r) & APD) != 0;
255 }
256 out_8(&adb->error.r, 0);
257 out_8(&adb->intr.r, 0);
258 }
259 spin_unlock(&macio_lock);
260 if (complete && req) {
261 void (*done)(struct adb_request *) = req->done;
262 mb();
263 req->complete = 1;
264 /* Here, we assume that if the request has a done member, the
265 * struct request will survive to setting req->complete to 1
266 */
267 if (done)
268 (*done)(req);
269 }
270 if (ibuf_len)
271 adb_input(ibuf, ibuf_len, regs, autopoll);
272
273 return IRQ_RETVAL(handled);
274}
275
276static void macio_adb_poll(void)
277{
278 unsigned long flags;
279
280 local_irq_save(flags);
281 if (in_8(&adb->intr.r) != 0)
282 macio_adb_interrupt(0, NULL, NULL);
283 local_irq_restore(flags);
284}