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/spinlock.h> 10 #include <linux/interrupt.h> 11 #include <asm/prom.h> 12 #include <linux/adb.h> 13 #include <asm/io.h> 14 #include <asm/pgtable.h> 15 #include <asm/hydra.h> 16 #include <asm/irq.h> 17 #include <asm/system.h> 18 #include <linux/init.h> 19 #include <linux/ioport.h> 20 21 struct preg { 22 unsigned char r; 23 char pad[15]; 24 }; 25 26 struct 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 60 static volatile struct adb_regs __iomem *adb; 61 static struct adb_request *current_req, *last_req; 62 static DEFINE_SPINLOCK(macio_lock); 63 64 static int macio_probe(void); 65 static int macio_init(void); 66 static irqreturn_t macio_adb_interrupt(int irq, void *arg); 67 static int macio_send_request(struct adb_request *req, int sync); 68 static int macio_adb_autopoll(int devs); 69 static void macio_adb_poll(void); 70 static int macio_adb_reset_bus(void); 71 72 struct 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 83 int macio_probe(void) 84 { 85 struct device_node *np; 86 87 np = of_find_compatible_node(NULL, "adb", "chrp,adb0"); 88 if (np) { 89 of_node_put(np); 90 return 0; 91 } 92 return -ENODEV; 93 } 94 95 int macio_init(void) 96 { 97 struct device_node *adbs; 98 struct resource r; 99 unsigned int irq; 100 101 adbs = of_find_compatible_node(NULL, "adb", "chrp,adb0"); 102 if (adbs == 0) 103 return -ENXIO; 104 105 if (of_address_to_resource(adbs, 0, &r)) { 106 of_node_put(adbs); 107 return -ENXIO; 108 } 109 adb = ioremap(r.start, sizeof(struct adb_regs)); 110 111 out_8(&adb->ctrl.r, 0); 112 out_8(&adb->intr.r, 0); 113 out_8(&adb->error.r, 0); 114 out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */ 115 out_8(&adb->active_lo.r, 0xff); 116 out_8(&adb->autopoll.r, APE); 117 118 irq = irq_of_parse_and_map(adbs, 0); 119 of_node_put(adbs); 120 if (request_irq(irq, macio_adb_interrupt, 0, "ADB", (void *)0)) { 121 printk(KERN_ERR "ADB: can't get irq %d\n", irq); 122 return -EAGAIN; 123 } 124 out_8(&adb->intr_enb.r, DFB | TAG); 125 126 printk("adb: mac-io driver 1.0 for unified ADB\n"); 127 128 return 0; 129 } 130 131 static int macio_adb_autopoll(int devs) 132 { 133 unsigned long flags; 134 135 spin_lock_irqsave(&macio_lock, flags); 136 out_8(&adb->active_hi.r, devs >> 8); 137 out_8(&adb->active_lo.r, devs); 138 out_8(&adb->autopoll.r, devs? APE: 0); 139 spin_unlock_irqrestore(&macio_lock, flags); 140 return 0; 141 } 142 143 static int macio_adb_reset_bus(void) 144 { 145 unsigned long flags; 146 int timeout = 1000000; 147 148 /* Hrm... we may want to not lock interrupts for so 149 * long ... oh well, who uses that chip anyway ? :) 150 * That function will be seldomly used during boot 151 * on rare machines, so... 152 */ 153 spin_lock_irqsave(&macio_lock, flags); 154 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST); 155 while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) { 156 if (--timeout == 0) { 157 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST); 158 spin_unlock_irqrestore(&macio_lock, flags); 159 return -1; 160 } 161 } 162 spin_unlock_irqrestore(&macio_lock, flags); 163 return 0; 164 } 165 166 /* Send an ADB command */ 167 static int macio_send_request(struct adb_request *req, int sync) 168 { 169 unsigned long flags; 170 int i; 171 172 if (req->data[0] != ADB_PACKET) 173 return -EINVAL; 174 175 for (i = 0; i < req->nbytes - 1; ++i) 176 req->data[i] = req->data[i+1]; 177 --req->nbytes; 178 179 req->next = NULL; 180 req->sent = 0; 181 req->complete = 0; 182 req->reply_len = 0; 183 184 spin_lock_irqsave(&macio_lock, flags); 185 if (current_req != 0) { 186 last_req->next = req; 187 last_req = req; 188 } else { 189 current_req = last_req = req; 190 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR); 191 } 192 spin_unlock_irqrestore(&macio_lock, flags); 193 194 if (sync) { 195 while (!req->complete) 196 macio_adb_poll(); 197 } 198 199 return 0; 200 } 201 202 static irqreturn_t macio_adb_interrupt(int irq, void *arg) 203 { 204 int i, n, err; 205 struct adb_request *req = NULL; 206 unsigned char ibuf[16]; 207 int ibuf_len = 0; 208 int complete = 0; 209 int autopoll = 0; 210 int handled = 0; 211 212 spin_lock(&macio_lock); 213 if (in_8(&adb->intr.r) & TAG) { 214 handled = 1; 215 if ((req = current_req) != 0) { 216 /* put the current request in */ 217 for (i = 0; i < req->nbytes; ++i) 218 out_8(&adb->data[i].r, req->data[i]); 219 out_8(&adb->dcount.r, req->nbytes & HMB); 220 req->sent = 1; 221 if (req->reply_expected) { 222 out_8(&adb->ctrl.r, DTB + CRE); 223 } else { 224 out_8(&adb->ctrl.r, DTB); 225 current_req = req->next; 226 complete = 1; 227 if (current_req) 228 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR); 229 } 230 } 231 out_8(&adb->intr.r, 0); 232 } 233 234 if (in_8(&adb->intr.r) & DFB) { 235 handled = 1; 236 err = in_8(&adb->error.r); 237 if (current_req && current_req->sent) { 238 /* this is the response to a command */ 239 req = current_req; 240 if (err == 0) { 241 req->reply_len = in_8(&adb->dcount.r) & HMB; 242 for (i = 0; i < req->reply_len; ++i) 243 req->reply[i] = in_8(&adb->data[i].r); 244 } 245 current_req = req->next; 246 complete = 1; 247 if (current_req) 248 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR); 249 } else if (err == 0) { 250 /* autopoll data */ 251 n = in_8(&adb->dcount.r) & HMB; 252 for (i = 0; i < n; ++i) 253 ibuf[i] = in_8(&adb->data[i].r); 254 ibuf_len = n; 255 autopoll = (in_8(&adb->dcount.r) & APD) != 0; 256 } 257 out_8(&adb->error.r, 0); 258 out_8(&adb->intr.r, 0); 259 } 260 spin_unlock(&macio_lock); 261 if (complete && req) { 262 void (*done)(struct adb_request *) = req->done; 263 mb(); 264 req->complete = 1; 265 /* Here, we assume that if the request has a done member, the 266 * struct request will survive to setting req->complete to 1 267 */ 268 if (done) 269 (*done)(req); 270 } 271 if (ibuf_len) 272 adb_input(ibuf, ibuf_len, autopoll); 273 274 return IRQ_RETVAL(handled); 275 } 276 277 static void macio_adb_poll(void) 278 { 279 unsigned long flags; 280 281 local_irq_save(flags); 282 if (in_8(&adb->intr.r) != 0) 283 macio_adb_interrupt(0, NULL); 284 local_irq_restore(flags); 285 } 286