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