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