ia64/linux-2.6.18-xen.hg

view drivers/macintosh/macio-adb.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
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>
22 struct preg {
23 unsigned char r;
24 char pad[15];
25 };
27 struct 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 };
40 /* Bits in intr and intr_enb registers */
41 #define DFB 1 /* data from bus */
42 #define TAG 2 /* transfer access grant */
44 /* Bits in dcount register */
45 #define HMB 0x0f /* how many bytes */
46 #define APD 0x10 /* auto-poll data */
48 /* Bits in error register */
49 #define NRE 1 /* no response error */
50 #define DLE 2 /* data lost error */
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 */
58 /* Bits in autopoll register */
59 #define APE 1 /* autopoll enable */
61 static volatile struct adb_regs __iomem *adb;
62 static struct adb_request *current_req, *last_req;
63 static DEFINE_SPINLOCK(macio_lock);
65 static int macio_probe(void);
66 static int macio_init(void);
67 static irqreturn_t macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs);
68 static int macio_send_request(struct adb_request *req, int sync);
69 static int macio_adb_autopoll(int devs);
70 static void macio_adb_poll(void);
71 static int macio_adb_reset_bus(void);
73 struct 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 };
84 int macio_probe(void)
85 {
86 return find_compatible_devices("adb", "chrp,adb0")? 0: -ENODEV;
87 }
89 int macio_init(void)
90 {
91 struct device_node *adbs;
92 struct resource r;
93 unsigned int irq;
95 adbs = find_compatible_devices("adb", "chrp,adb0");
96 if (adbs == 0)
97 return -ENXIO;
99 if (of_address_to_resource(adbs, 0, &r))
100 return -ENXIO;
101 adb = ioremap(r.start, sizeof(struct adb_regs));
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);
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);
117 printk("adb: mac-io driver 1.0 for unified ADB\n");
119 return 0;
120 }
122 static int macio_adb_autopoll(int devs)
123 {
124 unsigned long flags;
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 }
134 static int macio_adb_reset_bus(void)
135 {
136 unsigned long flags;
137 int timeout = 1000000;
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 }
156 /* Send an ADB command */
157 static int macio_send_request(struct adb_request *req, int sync)
158 {
159 unsigned long flags;
160 int i;
162 if (req->data[0] != ADB_PACKET)
163 return -EINVAL;
165 for (i = 0; i < req->nbytes - 1; ++i)
166 req->data[i] = req->data[i+1];
167 --req->nbytes;
169 req->next = NULL;
170 req->sent = 0;
171 req->complete = 0;
172 req->reply_len = 0;
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);
184 if (sync) {
185 while (!req->complete)
186 macio_adb_poll();
187 }
189 return 0;
190 }
192 static irqreturn_t macio_adb_interrupt(int irq, void *arg,
193 struct pt_regs *regs)
194 {
195 int i, n, err;
196 struct adb_request *req = NULL;
197 unsigned char ibuf[16];
198 int ibuf_len = 0;
199 int complete = 0;
200 int autopoll = 0;
201 int handled = 0;
203 spin_lock(&macio_lock);
204 if (in_8(&adb->intr.r) & TAG) {
205 handled = 1;
206 if ((req = current_req) != 0) {
207 /* put the current request in */
208 for (i = 0; i < req->nbytes; ++i)
209 out_8(&adb->data[i].r, req->data[i]);
210 out_8(&adb->dcount.r, req->nbytes & HMB);
211 req->sent = 1;
212 if (req->reply_expected) {
213 out_8(&adb->ctrl.r, DTB + CRE);
214 } else {
215 out_8(&adb->ctrl.r, DTB);
216 current_req = req->next;
217 complete = 1;
218 if (current_req)
219 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
220 }
221 }
222 out_8(&adb->intr.r, 0);
223 }
225 if (in_8(&adb->intr.r) & DFB) {
226 handled = 1;
227 err = in_8(&adb->error.r);
228 if (current_req && current_req->sent) {
229 /* this is the response to a command */
230 req = current_req;
231 if (err == 0) {
232 req->reply_len = in_8(&adb->dcount.r) & HMB;
233 for (i = 0; i < req->reply_len; ++i)
234 req->reply[i] = in_8(&adb->data[i].r);
235 }
236 current_req = req->next;
237 complete = 1;
238 if (current_req)
239 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
240 } else if (err == 0) {
241 /* autopoll data */
242 n = in_8(&adb->dcount.r) & HMB;
243 for (i = 0; i < n; ++i)
244 ibuf[i] = in_8(&adb->data[i].r);
245 ibuf_len = n;
246 autopoll = (in_8(&adb->dcount.r) & APD) != 0;
247 }
248 out_8(&adb->error.r, 0);
249 out_8(&adb->intr.r, 0);
250 }
251 spin_unlock(&macio_lock);
252 if (complete && req) {
253 void (*done)(struct adb_request *) = req->done;
254 mb();
255 req->complete = 1;
256 /* Here, we assume that if the request has a done member, the
257 * struct request will survive to setting req->complete to 1
258 */
259 if (done)
260 (*done)(req);
261 }
262 if (ibuf_len)
263 adb_input(ibuf, ibuf_len, regs, autopoll);
265 return IRQ_RETVAL(handled);
266 }
268 static void macio_adb_poll(void)
269 {
270 unsigned long flags;
272 local_irq_save(flags);
273 if (in_8(&adb->intr.r) != 0)
274 macio_adb_interrupt(0, NULL, NULL);
275 local_irq_restore(flags);
276 }