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