drivers/macintosh/windfarm_smu_sat.c

   1 /*
   2  * Windfarm PowerMac thermal control.  SMU "satellite" controller sensors.
   3  *
   4  * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
   5  *
   6  * Released under the terms of the GNU GPL v2.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/errno.h>
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/init.h>
  14 #include <linux/wait.h>
  15 #include <linux/i2c.h>
  16 #include <linux/i2c-dev.h>
  17 #include <asm/semaphore.h>
  18 #include <asm/prom.h>
  19 #include <asm/smu.h>
  20 #include <asm/pmac_low_i2c.h>
  21
  22 #include "windfarm.h"
  23
  24 #define VERSION "0.2"
  25
  26 #define DEBUG
  27
  28 #ifdef DEBUG
  29 #define DBG(args...)    printk(args)
  30 #else
  31 #define DBG(args...)    do { } while(0)
  32 #endif
  33
  34 /* If the cache is older than 800ms we'll refetch it */
  35 #define MAX_AGE         msecs_to_jiffies(800)
  36
  37 struct wf_sat {
  38         int                     nr;
  39         atomic_t                refcnt;
  40         struct semaphore        mutex;
  41         unsigned long           last_read; /* jiffies when cache last updated */
  42         u8                      cache[16];
  43         struct i2c_client       i2c;
  44         struct device_node      *node;
  45 };
  46
  47 static struct wf_sat *sats[2];
  48
  49 struct wf_sat_sensor {
  50         int             index;
  51         int             index2;         /* used for power sensors */
  52         int             shift;
  53         struct wf_sat   *sat;
  54         struct wf_sensor sens;
  55 };
  56
  57 #define wf_to_sat(c)    container_of(c, struct wf_sat_sensor, sens)
  58 #define i2c_to_sat(c)   container_of(c, struct wf_sat, i2c)
  59
  60 static int wf_sat_attach(struct i2c_adapter *adapter);
  61 static int wf_sat_detach(struct i2c_client *client);
  62
  63 static struct i2c_driver wf_sat_driver = {
  64         .driver = {
  65                 .name           = "wf_smu_sat",
  66         },
  67         .attach_adapter = wf_sat_attach,
  68         .detach_client  = wf_sat_detach,
  69 };
  70
  71 /*
  72  * XXX i2c_smbus_read_i2c_block_data doesn't pass the requested
  73  * length down to the low-level driver, so we use this, which
  74  * works well enough with the SMU i2c driver code...
  75  */
  76 static int sat_read_block(struct i2c_client *client, u8 command,
  77                           u8 *values, int len)
  78 {
  79         union i2c_smbus_data data;
  80         int err;
  81
  82         data.block[0] = len;
  83         err = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
  84                              I2C_SMBUS_READ, command, I2C_SMBUS_I2C_BLOCK_DATA,
  85                              &data);
  86         if (!err)
  87                 memcpy(values, data.block, len);
  88         return err;
  89 }
  90
  91 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
  92                                                   unsigned int *size)
  93 {
  94         struct wf_sat *sat;
  95         int err;
  96         unsigned int i, len;
  97         u8 *buf;
  98         u8 data[4];
  99
 100         /* TODO: Add the resulting partition to the device-tree */
 101
 102         if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
 103                 return NULL;
 104
 105         err = i2c_smbus_write_word_data(&sat->i2c, 8, id << 8);
 106         if (err) {
 107                 printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
 108                 return NULL;
 109         }
 110
 111         len = i2c_smbus_read_word_data(&sat->i2c, 9);
 112         if (len < 0) {
 113                 printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
 114                 return NULL;
 115         }
 116         if (len == 0) {
 117                 printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
 118                 return NULL;
 119         }
 120
 121         len = le16_to_cpu(len);
 122         len = (len + 3) & ~3;
 123         buf = kmalloc(len, GFP_KERNEL);
 124         if (buf == NULL)
 125                 return NULL;
 126
 127         for (i = 0; i < len; i += 4) {
 128                 err = sat_read_block(&sat->i2c, 0xa, data, 4);
 129                 if (err) {
 130                         printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
 131                                err);
 132                         goto fail;
 133                 }
 134                 buf[i] = data[1];
 135                 buf[i+1] = data[0];
 136                 buf[i+2] = data[3];
 137                 buf[i+3] = data[2];
 138         }
 139 #ifdef DEBUG
 140         DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
 141         for (i = 0; i < len; ++i)
 142                 DBG(" %x", buf[i]);
 143         DBG("\n");
 144 #endif
 145
 146         if (size)
 147                 *size = len;
 148         return (struct smu_sdbp_header *) buf;
 149
 150  fail:
 151         kfree(buf);
 152         return NULL;
 153 }
 154 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
 155
 156 /* refresh the cache */
 157 static int wf_sat_read_cache(struct wf_sat *sat)
 158 {
 159         int err;
 160
 161         err = sat_read_block(&sat->i2c, 0x3f, sat->cache, 16);
 162         if (err)
 163                 return err;
 164         sat->last_read = jiffies;
 165 #ifdef LOTSA_DEBUG
 166         {
 167                 int i;
 168                 DBG(KERN_DEBUG "wf_sat_get: data is");
 169                 for (i = 0; i < 16; ++i)
 170                         DBG(" %.2x", sat->cache[i]);
 171                 DBG("\n");
 172         }
 173 #endif
 174         return 0;
 175 }
 176
 177 static int wf_sat_get(struct wf_sensor *sr, s32 *value)
 178 {
 179         struct wf_sat_sensor *sens = wf_to_sat(sr);
 180         struct wf_sat *sat = sens->sat;
 181         int i, err;
 182         s32 val;
 183
 184         if (sat->i2c.adapter == NULL)
 185                 return -ENODEV;
 186
 187         down(&sat->mutex);
 188         if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
 189                 err = wf_sat_read_cache(sat);
 190                 if (err)
 191                         goto fail;
 192         }
 193
 194         i = sens->index * 2;
 195         val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
 196         if (sens->index2 >= 0) {
 197                 i = sens->index2 * 2;
 198                 /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
 199                 val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
 200         }
 201
 202         *value = val;
 203         err = 0;
 204
 205  fail:
 206         up(&sat->mutex);
 207         return err;
 208 }
 209
 210 static void wf_sat_release(struct wf_sensor *sr)
 211 {
 212         struct wf_sat_sensor *sens = wf_to_sat(sr);
 213         struct wf_sat *sat = sens->sat;
 214
 215         if (atomic_dec_and_test(&sat->refcnt)) {
 216                 if (sat->i2c.adapter) {
 217                         i2c_detach_client(&sat->i2c);
 218                         sat->i2c.adapter = NULL;
 219                 }
 220                 if (sat->nr >= 0)
 221                         sats[sat->nr] = NULL;
 222                 kfree(sat);
 223         }
 224         kfree(sens);
 225 }
 226
 227 static struct wf_sensor_ops wf_sat_ops = {
 228         .get_value      = wf_sat_get,
 229         .release        = wf_sat_release,
 230         .owner          = THIS_MODULE,
 231 };
 232
 233 static void wf_sat_create(struct i2c_adapter *adapter, struct device_node *dev)
 234 {
 235         struct wf_sat *sat;
 236         struct wf_sat_sensor *sens;
 237         u32 *reg;
 238         char *loc, *type;
 239         u8 addr, chip, core;
 240         struct device_node *child;
 241         int shift, cpu, index;
 242         char *name;
 243         int vsens[2], isens[2];
 244
 245         reg = (u32 *) get_property(dev, "reg", NULL);
 246         if (reg == NULL)
 247                 return;
 248         addr = *reg;
 249         DBG(KERN_DEBUG "wf_sat: creating sat at address %x\n", addr);
 250
 251         sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
 252         if (sat == NULL)
 253                 return;
 254         sat->nr = -1;
 255         sat->node = of_node_get(dev);
 256         atomic_set(&sat->refcnt, 0);
 257         init_MUTEX(&sat->mutex);
 258         sat->i2c.addr = (addr >> 1) & 0x7f;
 259         sat->i2c.adapter = adapter;
 260         sat->i2c.driver = &wf_sat_driver;
 261         strncpy(sat->i2c.name, "smu-sat", I2C_NAME_SIZE-1);
 262
 263         if (i2c_attach_client(&sat->i2c)) {
 264                 printk(KERN_ERR "windfarm: failed to attach smu-sat to i2c\n");
 265                 goto fail;
 266         }
 267
 268         vsens[0] = vsens[1] = -1;
 269         isens[0] = isens[1] = -1;
 270         child = NULL;
 271         while ((child = of_get_next_child(dev, child)) != NULL) {
 272                 reg = (u32 *) get_property(child, "reg", NULL);
 273                 type = get_property(child, "device_type", NULL);
 274                 loc = get_property(child, "location", NULL);
 275                 if (reg == NULL || loc == NULL)
 276                         continue;
 277
 278                 /* the cooked sensors are between 0x30 and 0x37 */
 279                 if (*reg < 0x30 || *reg > 0x37)
 280                         continue;
 281                 index = *reg - 0x30;
 282
 283                 /* expect location to be CPU [AB][01] ... */
 284                 if (strncmp(loc, "CPU ", 4) != 0)
 285                         continue;
 286                 chip = loc[4] - 'A';
 287                 core = loc[5] - '0';
 288                 if (chip > 1 || core > 1) {
 289                         printk(KERN_ERR "wf_sat_create: don't understand "
 290                                "location %s for %s\n", loc, child->full_name);
 291                         continue;
 292                 }
 293                 cpu = 2 * chip + core;
 294                 if (sat->nr < 0)
 295                         sat->nr = chip;
 296                 else if (sat->nr != chip) {
 297                         printk(KERN_ERR "wf_sat_create: can't cope with "
 298                                "multiple CPU chips on one SAT (%s)\n", loc);
 299                         continue;
 300                 }
 301
 302                 if (strcmp(type, "voltage-sensor") == 0) {
 303                         name = "cpu-voltage";
 304                         shift = 4;
 305                         vsens[core] = index;
 306                 } else if (strcmp(type, "current-sensor") == 0) {
 307                         name = "cpu-current";
 308                         shift = 8;
 309                         isens[core] = index;
 310                 } else if (strcmp(type, "temp-sensor") == 0) {
 311                         name = "cpu-temp";
 312                         shift = 10;
 313                 } else
 314                         continue;       /* hmmm shouldn't happen */
 315
 316                 /* the +16 is enough for "cpu-voltage-n" */
 317                 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 318                 if (sens == NULL) {
 319                         printk(KERN_ERR "wf_sat_create: couldn't create "
 320                                "%s sensor %d (no memory)\n", name, cpu);
 321                         continue;
 322                 }
 323                 sens->index = index;
 324                 sens->index2 = -1;
 325                 sens->shift = shift;
 326                 sens->sat = sat;
 327                 atomic_inc(&sat->refcnt);
 328                 sens->sens.ops = &wf_sat_ops;
 329                 sens->sens.name = (char *) (sens + 1);
 330                 snprintf(sens->sens.name, 16, "%s-%d", name, cpu);
 331
 332                 if (wf_register_sensor(&sens->sens)) {
 333                         atomic_dec(&sat->refcnt);
 334                         kfree(sens);
 335                 }
 336         }
 337
 338         /* make the power sensors */
 339         for (core = 0; core < 2; ++core) {
 340                 if (vsens[core] < 0 || isens[core] < 0)
 341                         continue;
 342                 cpu = 2 * sat->nr + core;
 343                 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 344                 if (sens == NULL) {
 345                         printk(KERN_ERR "wf_sat_create: couldn't create power "
 346                                "sensor %d (no memory)\n", cpu);
 347                         continue;
 348                 }
 349                 sens->index = vsens[core];
 350                 sens->index2 = isens[core];
 351                 sens->shift = 0;
 352                 sens->sat = sat;
 353                 atomic_inc(&sat->refcnt);
 354                 sens->sens.ops = &wf_sat_ops;
 355                 sens->sens.name = (char *) (sens + 1);
 356                 snprintf(sens->sens.name, 16, "cpu-power-%d", cpu);
 357
 358                 if (wf_register_sensor(&sens->sens)) {
 359                         atomic_dec(&sat->refcnt);
 360                         kfree(sens);
 361                 }
 362         }
 363
 364         if (sat->nr >= 0)
 365                 sats[sat->nr] = sat;
 366
 367         return;
 368
 369  fail:
 370         kfree(sat);
 371 }
 372
 373 static int wf_sat_attach(struct i2c_adapter *adapter)
 374 {
 375         struct device_node *busnode, *dev = NULL;
 376         struct pmac_i2c_bus *bus;
 377
 378         bus = pmac_i2c_adapter_to_bus(adapter);
 379         if (bus == NULL)
 380                 return -ENODEV;
 381         busnode = pmac_i2c_get_bus_node(bus);
 382
 383         while ((dev = of_get_next_child(busnode, dev)) != NULL)
 384                 if (device_is_compatible(dev, "smu-sat"))
 385                         wf_sat_create(adapter, dev);
 386         return 0;
 387 }
 388
 389 static int wf_sat_detach(struct i2c_client *client)
 390 {
 391         struct wf_sat *sat = i2c_to_sat(client);
 392
 393         /* XXX TODO */
 394
 395         sat->i2c.adapter = NULL;
 396         return 0;
 397 }
 398
 399 static int __init sat_sensors_init(void)
 400 {
 401         int err;
 402
 403         err = i2c_add_driver(&wf_sat_driver);
 404         if (err < 0)
 405                 return err;
 406         return 0;
 407 }
 408
 409 static void __exit sat_sensors_exit(void)
 410 {
 411         i2c_del_driver(&wf_sat_driver);
 412 }
 413
 414 module_init(sat_sensors_init);
 415 /*module_exit(sat_sensors_exit); Uncomment when cleanup is implemented */
 416
 417 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 418 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
 419 MODULE_LICENSE("GPL");