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