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
  58 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
  59                                                   unsigned int *size)
  60 {
  61         struct wf_sat *sat;
  62         int err;
  63         unsigned int i, len;
  64         u8 *buf;
  65         u8 data[4];
  66
  67         /* TODO: Add the resulting partition to the device-tree */
  68
  69         if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
  70                 return NULL;
  71
  72         err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
  73         if (err) {
  74                 printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
  75                 return NULL;
  76         }
  77
  78         err = i2c_smbus_read_word_data(sat->i2c, 9);
  79         if (err < 0) {
  80                 printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
  81                 return NULL;
  82         }
  83         len = err;
  84         if (len == 0) {
  85                 printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
  86                 return NULL;
  87         }
  88
  89         len = le16_to_cpu(len);
  90         len = (len + 3) & ~3;
  91         buf = kmalloc(len, GFP_KERNEL);
  92         if (buf == NULL)
  93                 return NULL;
  94
  95         for (i = 0; i < len; i += 4) {
  96                 err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
  97                 if (err < 0) {
  98                         printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
  99                                err);
 100                         goto fail;
 101                 }
 102                 buf[i] = data[1];
 103                 buf[i+1] = data[0];
 104                 buf[i+2] = data[3];
 105                 buf[i+3] = data[2];
 106         }
 107 #ifdef DEBUG
 108         DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
 109         for (i = 0; i < len; ++i)
 110                 DBG(" %x", buf[i]);
 111         DBG("\n");
 112 #endif
 113
 114         if (size)
 115                 *size = len;
 116         return (struct smu_sdbp_header *) buf;
 117
 118  fail:
 119         kfree(buf);
 120         return NULL;
 121 }
 122 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
 123
 124 /* refresh the cache */
 125 static int wf_sat_read_cache(struct wf_sat *sat)
 126 {
 127         int err;
 128
 129         err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
 130         if (err < 0)
 131                 return err;
 132         sat->last_read = jiffies;
 133 #ifdef LOTSA_DEBUG
 134         {
 135                 int i;
 136                 DBG(KERN_DEBUG "wf_sat_get: data is");
 137                 for (i = 0; i < 16; ++i)
 138                         DBG(" %.2x", sat->cache[i]);
 139                 DBG("\n");
 140         }
 141 #endif
 142         return 0;
 143 }
 144
 145 static int wf_sat_get(struct wf_sensor *sr, s32 *value)
 146 {
 147         struct wf_sat_sensor *sens = wf_to_sat(sr);
 148         struct wf_sat *sat = sens->sat;
 149         int i, err;
 150         s32 val;
 151
 152         if (sat->i2c == NULL)
 153                 return -ENODEV;
 154
 155         mutex_lock(&sat->mutex);
 156         if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
 157                 err = wf_sat_read_cache(sat);
 158                 if (err)
 159                         goto fail;
 160         }
 161
 162         i = sens->index * 2;
 163         val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
 164         if (sens->index2 >= 0) {
 165                 i = sens->index2 * 2;
 166                 /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
 167                 val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
 168         }
 169
 170         *value = val;
 171         err = 0;
 172
 173  fail:
 174         mutex_unlock(&sat->mutex);
 175         return err;
 176 }
 177
 178 static void wf_sat_release(struct wf_sensor *sr)
 179 {
 180         struct wf_sat_sensor *sens = wf_to_sat(sr);
 181         struct wf_sat *sat = sens->sat;
 182
 183         if (atomic_dec_and_test(&sat->refcnt)) {
 184                 if (sat->nr >= 0)
 185                         sats[sat->nr] = NULL;
 186                 kfree(sat);
 187         }
 188         kfree(sens);
 189 }
 190
 191 static struct wf_sensor_ops wf_sat_ops = {
 192         .get_value      = wf_sat_get,
 193         .release        = wf_sat_release,
 194         .owner          = THIS_MODULE,
 195 };
 196
 197 static struct i2c_driver wf_sat_driver;
 198
 199 static void wf_sat_create(struct i2c_adapter *adapter, struct device_node *dev)
 200 {
 201         struct i2c_board_info info;
 202         struct i2c_client *client;
 203         const u32 *reg;
 204         u8 addr;
 205
 206         reg = of_get_property(dev, "reg", NULL);
 207         if (reg == NULL)
 208                 return;
 209         addr = *reg;
 210         DBG(KERN_DEBUG "wf_sat: creating sat at address %x\n", addr);
 211
 212         memset(&info, 0, sizeof(struct i2c_board_info));
 213         info.addr = (addr >> 1) & 0x7f;
 214         info.platform_data = dev;
 215         strlcpy(info.type, "wf_sat", I2C_NAME_SIZE);
 216
 217         client = i2c_new_device(adapter, &info);
 218         if (client == NULL) {
 219                 printk(KERN_ERR "windfarm: failed to attach smu-sat to i2c\n");
 220                 return;
 221         }
 222
 223         /*
 224          * Let i2c-core delete that device on driver removal.
 225          * This is safe because i2c-core holds the core_lock mutex for us.
 226          */
 227         list_add_tail(&client->detected, &wf_sat_driver.clients);
 228 }
 229
 230 static int wf_sat_probe(struct i2c_client *client,
 231                         const struct i2c_device_id *id)
 232 {
 233         struct device_node *dev = client->dev.platform_data;
 234         struct wf_sat *sat;
 235         struct wf_sat_sensor *sens;
 236         const u32 *reg;
 237         const char *loc, *type;
 238         u8 chip, core;
 239         struct device_node *child;
 240         int shift, cpu, index;
 241         char *name;
 242         int vsens[2], isens[2];
 243
 244         sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
 245         if (sat == NULL)
 246                 return -ENOMEM;
 247         sat->nr = -1;
 248         sat->node = of_node_get(dev);
 249         atomic_set(&sat->refcnt, 0);
 250         mutex_init(&sat->mutex);
 251         sat->i2c = client;
 252         i2c_set_clientdata(client, sat);
 253
 254         vsens[0] = vsens[1] = -1;
 255         isens[0] = isens[1] = -1;
 256         child = NULL;
 257         while ((child = of_get_next_child(dev, child)) != NULL) {
 258                 reg = of_get_property(child, "reg", NULL);
 259                 type = of_get_property(child, "device_type", NULL);
 260                 loc = of_get_property(child, "location", NULL);
 261                 if (reg == NULL || loc == NULL)
 262                         continue;
 263
 264                 /* the cooked sensors are between 0x30 and 0x37 */
 265                 if (*reg < 0x30 || *reg > 0x37)
 266                         continue;
 267                 index = *reg - 0x30;
 268
 269                 /* expect location to be CPU [AB][01] ... */
 270                 if (strncmp(loc, "CPU ", 4) != 0)
 271                         continue;
 272                 chip = loc[4] - 'A';
 273                 core = loc[5] - '0';
 274                 if (chip > 1 || core > 1) {
 275                         printk(KERN_ERR "wf_sat_create: don't understand "
 276                                "location %s for %s\n", loc, child->full_name);
 277                         continue;
 278                 }
 279                 cpu = 2 * chip + core;
 280                 if (sat->nr < 0)
 281                         sat->nr = chip;
 282                 else if (sat->nr != chip) {
 283                         printk(KERN_ERR "wf_sat_create: can't cope with "
 284                                "multiple CPU chips on one SAT (%s)\n", loc);
 285                         continue;
 286                 }
 287
 288                 if (strcmp(type, "voltage-sensor") == 0) {
 289                         name = "cpu-voltage";
 290                         shift = 4;
 291                         vsens[core] = index;
 292                 } else if (strcmp(type, "current-sensor") == 0) {
 293                         name = "cpu-current";
 294                         shift = 8;
 295                         isens[core] = index;
 296                 } else if (strcmp(type, "temp-sensor") == 0) {
 297                         name = "cpu-temp";
 298                         shift = 10;
 299                 } else
 300                         continue;       /* hmmm shouldn't happen */
 301
 302                 /* the +16 is enough for "cpu-voltage-n" */
 303                 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 304                 if (sens == NULL) {
 305                         printk(KERN_ERR "wf_sat_create: couldn't create "
 306                                "%s sensor %d (no memory)\n", name, cpu);
 307                         continue;
 308                 }
 309                 sens->index = index;
 310                 sens->index2 = -1;
 311                 sens->shift = shift;
 312                 sens->sat = sat;
 313                 atomic_inc(&sat->refcnt);
 314                 sens->sens.ops = &wf_sat_ops;
 315                 sens->sens.name = (char *) (sens + 1);
 316                 snprintf(sens->sens.name, 16, "%s-%d", name, cpu);
 317
 318                 if (wf_register_sensor(&sens->sens)) {
 319                         atomic_dec(&sat->refcnt);
 320                         kfree(sens);
 321                 }
 322         }
 323
 324         /* make the power sensors */
 325         for (core = 0; core < 2; ++core) {
 326                 if (vsens[core] < 0 || isens[core] < 0)
 327                         continue;
 328                 cpu = 2 * sat->nr + core;
 329                 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 330                 if (sens == NULL) {
 331                         printk(KERN_ERR "wf_sat_create: couldn't create power "
 332                                "sensor %d (no memory)\n", cpu);
 333                         continue;
 334                 }
 335                 sens->index = vsens[core];
 336                 sens->index2 = isens[core];
 337                 sens->shift = 0;
 338                 sens->sat = sat;
 339                 atomic_inc(&sat->refcnt);
 340                 sens->sens.ops = &wf_sat_ops;
 341                 sens->sens.name = (char *) (sens + 1);
 342                 snprintf(sens->sens.name, 16, "cpu-power-%d", cpu);
 343
 344                 if (wf_register_sensor(&sens->sens)) {
 345                         atomic_dec(&sat->refcnt);
 346                         kfree(sens);
 347                 }
 348         }
 349
 350         if (sat->nr >= 0)
 351                 sats[sat->nr] = sat;
 352
 353         return 0;
 354 }
 355
 356 static int wf_sat_attach(struct i2c_adapter *adapter)
 357 {
 358         struct device_node *busnode, *dev = NULL;
 359         struct pmac_i2c_bus *bus;
 360
 361         bus = pmac_i2c_adapter_to_bus(adapter);
 362         if (bus == NULL)
 363                 return -ENODEV;
 364         busnode = pmac_i2c_get_bus_node(bus);
 365
 366         while ((dev = of_get_next_child(busnode, dev)) != NULL)
 367                 if (of_device_is_compatible(dev, "smu-sat"))
 368                         wf_sat_create(adapter, dev);
 369         return 0;
 370 }
 371
 372 static int wf_sat_remove(struct i2c_client *client)
 373 {
 374         struct wf_sat *sat = i2c_get_clientdata(client);
 375
 376         /* XXX TODO */
 377
 378         sat->i2c = NULL;
 379         return 0;
 380 }
 381
 382 static const struct i2c_device_id wf_sat_id[] = {
 383         { "wf_sat", 0 },
 384         { }
 385 };
 386
 387 static struct i2c_driver wf_sat_driver = {
 388         .driver = {
 389                 .name           = "wf_smu_sat",
 390         },
 391         .attach_adapter = wf_sat_attach,
 392         .probe          = wf_sat_probe,
 393         .remove         = wf_sat_remove,
 394         .id_table       = wf_sat_id,
 395 };
 396
 397 static int __init sat_sensors_init(void)
 398 {
 399         return i2c_add_driver(&wf_sat_driver);
 400 }
 401
 402 #if 0   /* uncomment when module_exit() below is uncommented */
 403 static void __exit sat_sensors_exit(void)
 404 {
 405         i2c_del_driver(&wf_sat_driver);
 406 }
 407 #endif
 408
 409 module_init(sat_sensors_init);
 410 /*module_exit(sat_sensors_exit); Uncomment when cleanup is implemented */
 411
 412 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 413 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
 414 MODULE_LICENSE("GPL");