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 "1.0"
  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         struct kref             ref;
  38         int                     nr;
  39         struct mutex            mutex;
  40         unsigned long           last_read; /* jiffies when cache last updated */
  41         u8                      cache[16];
  42         struct list_head        sensors;
  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         struct list_head        link;
  51         int                     index;
  52         int                     index2;         /* used for power sensors */
  53         int                     shift;
  54         struct wf_sat           *sat;
  55         struct wf_sensor        sens;
  56 };
  57
  58 #define wf_to_sat(c)    container_of(c, struct wf_sat_sensor, sens)
  59
  60 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
  61                                                   unsigned int *size)
  62 {
  63         struct wf_sat *sat;
  64         int err;
  65         unsigned int i, len;
  66         u8 *buf;
  67         u8 data[4];
  68
  69         /* TODO: Add the resulting partition to the device-tree */
  70
  71         if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
  72                 return NULL;
  73
  74         err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
  75         if (err) {
  76                 printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
  77                 return NULL;
  78         }
  79
  80         err = i2c_smbus_read_word_data(sat->i2c, 9);
  81         if (err < 0) {
  82                 printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
  83                 return NULL;
  84         }
  85         len = err;
  86         if (len == 0) {
  87                 printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
  88                 return NULL;
  89         }
  90
  91         len = le16_to_cpu(len);
  92         len = (len + 3) & ~3;
  93         buf = kmalloc(len, GFP_KERNEL);
  94         if (buf == NULL)
  95                 return NULL;
  96
  97         for (i = 0; i < len; i += 4) {
  98                 err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
  99                 if (err < 0) {
 100                         printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
 101                                err);
 102                         goto fail;
 103                 }
 104                 buf[i] = data[1];
 105                 buf[i+1] = data[0];
 106                 buf[i+2] = data[3];
 107                 buf[i+3] = data[2];
 108         }
 109 #ifdef DEBUG
 110         DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
 111         for (i = 0; i < len; ++i)
 112                 DBG(" %x", buf[i]);
 113         DBG("\n");
 114 #endif
 115
 116         if (size)
 117                 *size = len;
 118         return (struct smu_sdbp_header *) buf;
 119
 120  fail:
 121         kfree(buf);
 122         return NULL;
 123 }
 124 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
 125
 126 /* refresh the cache */
 127 static int wf_sat_read_cache(struct wf_sat *sat)
 128 {
 129         int err;
 130
 131         err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
 132         if (err < 0)
 133                 return err;
 134         sat->last_read = jiffies;
 135 #ifdef LOTSA_DEBUG
 136         {
 137                 int i;
 138                 DBG(KERN_DEBUG "wf_sat_get: data is");
 139                 for (i = 0; i < 16; ++i)
 140                         DBG(" %.2x", sat->cache[i]);
 141                 DBG("\n");
 142         }
 143 #endif
 144         return 0;
 145 }
 146
 147 static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
 148 {
 149         struct wf_sat_sensor *sens = wf_to_sat(sr);
 150         struct wf_sat *sat = sens->sat;
 151         int i, err;
 152         s32 val;
 153
 154         if (sat->i2c == NULL)
 155                 return -ENODEV;
 156
 157         mutex_lock(&sat->mutex);
 158         if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
 159                 err = wf_sat_read_cache(sat);
 160                 if (err)
 161                         goto fail;
 162         }
 163
 164         i = sens->index * 2;
 165         val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
 166         if (sens->index2 >= 0) {
 167                 i = sens->index2 * 2;
 168                 /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
 169                 val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
 170         }
 171
 172         *value = val;
 173         err = 0;
 174
 175  fail:
 176         mutex_unlock(&sat->mutex);
 177         return err;
 178 }
 179
 180 static void wf_sat_release(struct kref *ref)
 181 {
 182         struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
 183
 184         if (sat->nr >= 0)
 185                 sats[sat->nr] = NULL;
 186         kfree(sat);
 187 }
 188
 189 static void wf_sat_sensor_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         kfree(sens);
 195         kref_put(&sat->ref, wf_sat_release);
 196 }
 197
 198 static const struct wf_sensor_ops wf_sat_ops = {
 199         .get_value      = wf_sat_sensor_get,
 200         .release        = wf_sat_sensor_release,
 201         .owner          = THIS_MODULE,
 202 };
 203
 204 static int wf_sat_probe(struct i2c_client *client,
 205                         const struct i2c_device_id *id)
 206 {
 207         struct device_node *dev = client->dev.of_node;
 208         struct wf_sat *sat;
 209         struct wf_sat_sensor *sens;
 210         const u32 *reg;
 211         const char *loc, *type;
 212         u8 chip, core;
 213         struct device_node *child;
 214         int shift, cpu, index;
 215         char *name;
 216         int vsens[2], isens[2];
 217
 218         sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
 219         if (sat == NULL)
 220                 return -ENOMEM;
 221         sat->nr = -1;
 222         sat->node = of_node_get(dev);
 223         kref_init(&sat->ref);
 224         mutex_init(&sat->mutex);
 225         sat->i2c = client;
 226         INIT_LIST_HEAD(&sat->sensors);
 227         i2c_set_clientdata(client, sat);
 228
 229         vsens[0] = vsens[1] = -1;
 230         isens[0] = isens[1] = -1;
 231         child = NULL;
 232         while ((child = of_get_next_child(dev, child)) != NULL) {
 233                 reg = of_get_property(child, "reg", NULL);
 234                 type = of_get_property(child, "device_type", NULL);
 235                 loc = of_get_property(child, "location", NULL);
 236                 if (reg == NULL || loc == NULL)
 237                         continue;
 238
 239                 /* the cooked sensors are between 0x30 and 0x37 */
 240                 if (*reg < 0x30 || *reg > 0x37)
 241                         continue;
 242                 index = *reg - 0x30;
 243
 244                 /* expect location to be CPU [AB][01] ... */
 245                 if (strncmp(loc, "CPU ", 4) != 0)
 246                         continue;
 247                 chip = loc[4] - 'A';
 248                 core = loc[5] - '0';
 249                 if (chip > 1 || core > 1) {
 250                         printk(KERN_ERR "wf_sat_create: don't understand "
 251                                "location %s for %pOF\n", loc, child);
 252                         continue;
 253                 }
 254                 cpu = 2 * chip + core;
 255                 if (sat->nr < 0)
 256                         sat->nr = chip;
 257                 else if (sat->nr != chip) {
 258                         printk(KERN_ERR "wf_sat_create: can't cope with "
 259                                "multiple CPU chips on one SAT (%s)\n", loc);
 260                         continue;
 261                 }
 262
 263                 if (strcmp(type, "voltage-sensor") == 0) {
 264                         name = "cpu-voltage";
 265                         shift = 4;
 266                         vsens[core] = index;
 267                 } else if (strcmp(type, "current-sensor") == 0) {
 268                         name = "cpu-current";
 269                         shift = 8;
 270                         isens[core] = index;
 271                 } else if (strcmp(type, "temp-sensor") == 0) {
 272                         name = "cpu-temp";
 273                         shift = 10;
 274                 } else
 275                         continue;       /* hmmm shouldn't happen */
 276
 277                 /* the +16 is enough for "cpu-voltage-n" */
 278                 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 279                 if (sens == NULL) {
 280                         printk(KERN_ERR "wf_sat_create: couldn't create "
 281                                "%s sensor %d (no memory)\n", name, cpu);
 282                         continue;
 283                 }
 284                 sens->index = index;
 285                 sens->index2 = -1;
 286                 sens->shift = shift;
 287                 sens->sat = sat;
 288                 sens->sens.ops = &wf_sat_ops;
 289                 sens->sens.name = (char *) (sens + 1);
 290                 snprintf((char *)sens->sens.name, 16, "%s-%d", name, cpu);
 291
 292                 if (wf_register_sensor(&sens->sens))
 293                         kfree(sens);
 294                 else {
 295                         list_add(&sens->link, &sat->sensors);
 296                         kref_get(&sat->ref);
 297                 }
 298         }
 299
 300         /* make the power sensors */
 301         for (core = 0; core < 2; ++core) {
 302                 if (vsens[core] < 0 || isens[core] < 0)
 303                         continue;
 304                 cpu = 2 * sat->nr + core;
 305                 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 306                 if (sens == NULL) {
 307                         printk(KERN_ERR "wf_sat_create: couldn't create power "
 308                                "sensor %d (no memory)\n", cpu);
 309                         continue;
 310                 }
 311                 sens->index = vsens[core];
 312                 sens->index2 = isens[core];
 313                 sens->shift = 0;
 314                 sens->sat = sat;
 315                 sens->sens.ops = &wf_sat_ops;
 316                 sens->sens.name = (char *) (sens + 1);
 317                 snprintf((char *)sens->sens.name, 16, "cpu-power-%d", cpu);
 318
 319                 if (wf_register_sensor(&sens->sens))
 320                         kfree(sens);
 321                 else {
 322                         list_add(&sens->link, &sat->sensors);
 323                         kref_get(&sat->ref);
 324                 }
 325         }
 326
 327         if (sat->nr >= 0)
 328                 sats[sat->nr] = sat;
 329
 330         return 0;
 331 }
 332
 333 static int wf_sat_remove(struct i2c_client *client)
 334 {
 335         struct wf_sat *sat = i2c_get_clientdata(client);
 336         struct wf_sat_sensor *sens;
 337
 338         /* release sensors */
 339         while(!list_empty(&sat->sensors)) {
 340                 sens = list_first_entry(&sat->sensors,
 341                                         struct wf_sat_sensor, link);
 342                 list_del(&sens->link);
 343                 wf_unregister_sensor(&sens->sens);
 344         }
 345         sat->i2c = NULL;
 346         kref_put(&sat->ref, wf_sat_release);
 347
 348         return 0;
 349 }
 350
 351 static const struct i2c_device_id wf_sat_id[] = {
 352         { "MAC,smu-sat", 0 },
 353         { }
 354 };
 355 MODULE_DEVICE_TABLE(i2c, wf_sat_id);
 356
 357 static struct i2c_driver wf_sat_driver = {
 358         .driver = {
 359                 .name           = "wf_smu_sat",
 360         },
 361         .probe          = wf_sat_probe,
 362         .remove         = wf_sat_remove,
 363         .id_table       = wf_sat_id,
 364 };
 365
 366 module_i2c_driver(wf_sat_driver);
 367
 368 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 369 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
 370 MODULE_LICENSE("GPL");