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 22 struct preg { 23 unsigned char r; 24 char pad[15]; 25 }; 26 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 }; 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 61 static volatile struct adb_regs __iomem *adb; 62 static struct adb_request *current_req, *last_req; 63 static DEFINE_SPINLOCK(macio_lock); 64 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); 72 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 }; 83 84 int macio_probe(void) 85 { 86 return find_compatible_devices("adb", "chrp,adb0")? 0: -ENODEV; 87 } 88 89 int macio_init(void) 90 { 91 struct device_node *adbs; 92 struct resource r; 93 94 adbs = find_compatible_devices("adb", "chrp,adb0"); 95 if (adbs == 0) 96 return -ENXIO; 97 98 #if 0 99 { int i = 0; 100 101 printk("macio_adb_init: node = %p, addrs =", adbs->node); 102 while(!of_address_to_resource(adbs, i, &r)) 103 printk(" %x(%x)", r.start, r.end - r.start); 104 printk(", intrs ="); 105 for (i = 0; i < adbs->n_intrs; ++i) 106 printk(" %x", adbs->intrs[i].line); 107 printk("\n"); } 108 #endif 109 if (of_address_to_resource(adbs, 0, &r)) 110 return -ENXIO; 111 adb = ioremap(r.start, sizeof(struct adb_regs)); 112 113 out_8(&adb->ctrl.r, 0); 114 out_8(&adb->intr.r, 0); 115 out_8(&adb->error.r, 0); 116 out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */ 117 out_8(&adb->active_lo.r, 0xff); 118 out_8(&adb->autopoll.r, APE); 119 120 if (request_irq(adbs->intrs[0].line, macio_adb_interrupt, 121 0, "ADB", (void *)0)) { 122 printk(KERN_ERR "ADB: can't get irq %d\n", 123 adbs->intrs[0].line); 124 return -EAGAIN; 125 } 126 out_8(&adb->intr_enb.r, DFB | TAG); 127 128 printk("adb: mac-io driver 1.0 for unified ADB\n"); 129 130 return 0; 131 } 132 133 static int macio_adb_autopoll(int devs) 134 { 135 unsigned long flags; 136 137 spin_lock_irqsave(&macio_lock, flags); 138 out_8(&adb->active_hi.r, devs >> 8); 139 out_8(&adb->active_lo.r, devs); 140 out_8(&adb->autopoll.r, devs? APE: 0); 141 spin_unlock_irqrestore(&macio_lock, flags); 142 return 0; 143 } 144 145 static int macio_adb_reset_bus(void) 146 { 147 unsigned long flags; 148 int timeout = 1000000; 149 150 /* Hrm... we may want to not lock interrupts for so 151 * long ... oh well, who uses that chip anyway ? :) 152 * That function will be seldomly used during boot 153 * on rare machines, so... 154 */ 155 spin_lock_irqsave(&macio_lock, flags); 156 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST); 157 while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) { 158 if (--timeout == 0) { 159 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST); 160 return -1; 161 } 162 } 163 spin_unlock_irqrestore(&macio_lock, flags); 164 return 0; 165 } 166 167 /* Send an ADB command */ 168 static int macio_send_request(struct adb_request *req, int sync) 169 { 170 unsigned long flags; 171 int i; 172 173 if (req->data[0] != ADB_PACKET) 174 return -EINVAL; 175 176 for (i = 0; i < req->nbytes - 1; ++i) 177 req->data[i] = req->data[i+1]; 178 --req->nbytes; 179 180 req->next = NULL; 181 req->sent = 0; 182 req->complete = 0; 183 req->reply_len = 0; 184 185 spin_lock_irqsave(&macio_lock, flags); 186 if (current_req != 0) { 187 last_req->next = req; 188 last_req = req; 189 } else { 190 current_req = last_req = req; 191 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR); 192 } 193 spin_unlock_irqrestore(&macio_lock, flags); 194 195 if (sync) { 196 while (!req->complete) 197 macio_adb_poll(); 198 } 199 200 return 0; 201 } 202 203 static irqreturn_t macio_adb_interrupt(int irq, void *arg, 204 struct pt_regs *regs) 205 { 206 int i, n, err; 207 struct adb_request *req = NULL; 208 unsigned char ibuf[16]; 209 int ibuf_len = 0; 210 int complete = 0; 211 int autopoll = 0; 212 int handled = 0; 213 214 spin_lock(&macio_lock); 215 if (in_8(&adb->intr.r) & TAG) { 216 handled = 1; 217 if ((req = current_req) != 0) { 218 /* put the current request in */ 219 for (i = 0; i < req->nbytes; ++i) 220 out_8(&adb->data[i].r, req->data[i]); 221 out_8(&adb->dcount.r, req->nbytes & HMB); 222 req->sent = 1; 223 if (req->reply_expected) { 224 out_8(&adb->ctrl.r, DTB + CRE); 225 } else { 226 out_8(&adb->ctrl.r, DTB); 227 current_req = req->next; 228 complete = 1; 229 if (current_req) 230 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR); 231 } 232 } 233 out_8(&adb->intr.r, 0); 234 } 235 236 if (in_8(&adb->intr.r) & DFB) { 237 handled = 1; 238 err = in_8(&adb->error.r); 239 if (current_req && current_req->sent) { 240 /* this is the response to a command */ 241 req = current_req; 242 if (err == 0) { 243 req->reply_len = in_8(&adb->dcount.r) & HMB; 244 for (i = 0; i < req->reply_len; ++i) 245 req->reply[i] = in_8(&adb->data[i].r); 246 } 247 current_req = req->next; 248 complete = 1; 249 if (current_req) 250 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR); 251 } else if (err == 0) { 252 /* autopoll data */ 253 n = in_8(&adb->dcount.r) & HMB; 254 for (i = 0; i < n; ++i) 255 ibuf[i] = in_8(&adb->data[i].r); 256 ibuf_len = n; 257 autopoll = (in_8(&adb->dcount.r) & APD) != 0; 258 } 259 out_8(&adb->error.r, 0); 260 out_8(&adb->intr.r, 0); 261 } 262 spin_unlock(&macio_lock); 263 if (complete && req) { 264 void (*done)(struct adb_request *) = req->done; 265 mb(); 266 req->complete = 1; 267 /* Here, we assume that if the request has a done member, the 268 * struct request will survive to setting req->complete to 1 269 */ 270 if (done) 271 (*done)(req); 272 } 273 if (ibuf_len) 274 adb_input(ibuf, ibuf_len, regs, autopoll); 275 276 return IRQ_RETVAL(handled); 277 } 278 279 static void macio_adb_poll(void) 280 { 281 unsigned long flags; 282 283 local_irq_save(flags); 284 if (in_8(&adb->intr.r) != 0) 285 macio_adb_interrupt(0, NULL, NULL); 286 local_irq_restore(flags); 287 } 288