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