298 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * I/O Processor (IOP) ADB Driver4 * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)5 * Based on via-cuda.c by Paul Mackerras.6 *7 * 1999-07-01 (jmt) - First implementation for new driver architecture.8 *9 * 1999-07-31 (jmt) - First working version.10 */11 12#include <linux/types.h>13#include <linux/kernel.h>14#include <linux/mm.h>15#include <linux/delay.h>16#include <linux/init.h>17 18#include <asm/macintosh.h>19#include <asm/macints.h>20#include <asm/mac_iop.h>21#include <asm/adb_iop.h>22#include <linux/unaligned.h>23 24#include <linux/adb.h>25 26static struct adb_request *current_req;27static struct adb_request *last_req;28static unsigned int autopoll_devs;29static u8 autopoll_addr;30 31static enum adb_iop_state {32 idle,33 sending,34 awaiting_reply35} adb_iop_state;36 37static void adb_iop_start(void);38static int adb_iop_probe(void);39static int adb_iop_init(void);40static int adb_iop_send_request(struct adb_request *, int);41static int adb_iop_write(struct adb_request *);42static int adb_iop_autopoll(int);43static void adb_iop_poll(void);44static int adb_iop_reset_bus(void);45 46/* ADB command byte structure */47#define ADDR_MASK 0xF048#define OP_MASK 0x0C49#define TALK 0x0C50 51struct adb_driver adb_iop_driver = {52 .name = "ISM IOP",53 .probe = adb_iop_probe,54 .init = adb_iop_init,55 .send_request = adb_iop_send_request,56 .autopoll = adb_iop_autopoll,57 .poll = adb_iop_poll,58 .reset_bus = adb_iop_reset_bus59};60 61static void adb_iop_done(void)62{63 struct adb_request *req = current_req;64 65 adb_iop_state = idle;66 67 req->complete = 1;68 current_req = req->next;69 if (req->done)70 (*req->done)(req);71 72 if (adb_iop_state == idle)73 adb_iop_start();74}75 76/*77 * Completion routine for ADB commands sent to the IOP.78 *79 * This will be called when a packet has been successfully sent.80 */81 82static void adb_iop_complete(struct iop_msg *msg)83{84 unsigned long flags;85 86 local_irq_save(flags);87 88 adb_iop_state = awaiting_reply;89 90 local_irq_restore(flags);91}92 93/*94 * Listen for ADB messages from the IOP.95 *96 * This will be called when unsolicited IOP messages are received.97 * These IOP messages can carry ADB autopoll responses and also occur98 * after explicit ADB commands.99 */100 101static void adb_iop_listen(struct iop_msg *msg)102{103 struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;104 u8 addr = (amsg->cmd & ADDR_MASK) >> 4;105 u8 op = amsg->cmd & OP_MASK;106 unsigned long flags;107 bool req_done = false;108 109 local_irq_save(flags);110 111 /* Responses to Talk commands may be unsolicited as they are112 * produced when the IOP polls devices. They are mostly timeouts.113 */114 if (op == TALK && ((1 << addr) & autopoll_devs))115 autopoll_addr = addr;116 117 switch (amsg->flags & (ADB_IOP_EXPLICIT |118 ADB_IOP_AUTOPOLL |119 ADB_IOP_TIMEOUT)) {120 case ADB_IOP_EXPLICIT:121 case ADB_IOP_EXPLICIT | ADB_IOP_TIMEOUT:122 if (adb_iop_state == awaiting_reply) {123 struct adb_request *req = current_req;124 125 if (req->reply_expected) {126 req->reply_len = amsg->count + 1;127 memcpy(req->reply, &amsg->cmd, req->reply_len);128 }129 130 req_done = true;131 }132 break;133 case ADB_IOP_AUTOPOLL:134 if (((1 << addr) & autopoll_devs) &&135 amsg->cmd == ADB_READREG(addr, 0))136 adb_input(&amsg->cmd, amsg->count + 1, 1);137 break;138 }139 msg->reply[0] = autopoll_addr ? ADB_IOP_AUTOPOLL : 0;140 msg->reply[1] = 0;141 msg->reply[2] = autopoll_addr ? ADB_READREG(autopoll_addr, 0) : 0;142 iop_complete_message(msg);143 144 if (req_done)145 adb_iop_done();146 147 local_irq_restore(flags);148}149 150/*151 * Start sending an ADB packet, IOP style152 *153 * There isn't much to do other than hand the packet over to the IOP154 * after encapsulating it in an adb_iopmsg.155 */156 157static void adb_iop_start(void)158{159 struct adb_request *req;160 struct adb_iopmsg amsg;161 162 /* get the packet to send */163 req = current_req;164 if (!req)165 return;166 167 /* The IOP takes MacII-style packets, so strip the initial168 * ADB_PACKET byte.169 */170 amsg.flags = ADB_IOP_EXPLICIT;171 amsg.count = req->nbytes - 2;172 173 /* amsg.data immediately follows amsg.cmd, effectively making174 * &amsg.cmd a pointer to the beginning of a full ADB packet.175 */176 memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);177 178 req->sent = 1;179 adb_iop_state = sending;180 181 /* Now send it. The IOP manager will call adb_iop_complete182 * when the message has been sent.183 */184 iop_send_message(ADB_IOP, ADB_CHAN, req, sizeof(amsg), (__u8 *)&amsg,185 adb_iop_complete);186}187 188static int adb_iop_probe(void)189{190 if (!iop_ism_present)191 return -ENODEV;192 return 0;193}194 195static int adb_iop_init(void)196{197 pr_info("adb: IOP ISM driver v0.4 for Unified ADB\n");198 iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");199 return 0;200}201 202static int adb_iop_send_request(struct adb_request *req, int sync)203{204 int err;205 206 err = adb_iop_write(req);207 if (err)208 return err;209 210 if (sync) {211 while (!req->complete)212 adb_iop_poll();213 }214 return 0;215}216 217static int adb_iop_write(struct adb_request *req)218{219 unsigned long flags;220 221 if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {222 req->complete = 1;223 return -EINVAL;224 }225 226 req->next = NULL;227 req->sent = 0;228 req->complete = 0;229 req->reply_len = 0;230 231 local_irq_save(flags);232 233 if (current_req) {234 last_req->next = req;235 last_req = req;236 } else {237 current_req = req;238 last_req = req;239 }240 241 if (adb_iop_state == idle)242 adb_iop_start();243 244 local_irq_restore(flags);245 246 return 0;247}248 249static void adb_iop_set_ap_complete(struct iop_msg *msg)250{251 struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;252 253 autopoll_devs = get_unaligned_be16(amsg->data);254 if (autopoll_devs & (1 << autopoll_addr))255 return;256 autopoll_addr = autopoll_devs ? (ffs(autopoll_devs) - 1) : 0;257}258 259static int adb_iop_autopoll(int devs)260{261 struct adb_iopmsg amsg;262 unsigned long flags;263 unsigned int mask = (unsigned int)devs & 0xFFFE;264 265 local_irq_save(flags);266 267 amsg.flags = ADB_IOP_SET_AUTOPOLL | (mask ? ADB_IOP_AUTOPOLL : 0);268 amsg.count = 2;269 amsg.cmd = 0;270 put_unaligned_be16(mask, amsg.data);271 272 iop_send_message(ADB_IOP, ADB_CHAN, NULL, sizeof(amsg), (__u8 *)&amsg,273 adb_iop_set_ap_complete);274 275 local_irq_restore(flags);276 277 return 0;278}279 280static void adb_iop_poll(void)281{282 iop_ism_irq_poll(ADB_IOP);283}284 285static int adb_iop_reset_bus(void)286{287 struct adb_request req;288 289 /* Command = 0, Address = ignored */290 adb_request(&req, NULL, ADBREQ_NOSEND, 1, ADB_BUSRESET);291 adb_iop_send_request(&req, 1);292 293 /* Don't want any more requests during the Global Reset low time. */294 mdelay(3);295 296 return 0;297}298