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windfarm_smu_sensors.c
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1 /*
2  * Windfarm PowerMac thermal control. SMU based sensors
3  *
4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6  *
7  * Released under the term of the GNU GPL v2.
8  */
9 
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/wait.h>
17 #include <linux/completion.h>
18 #include <asm/prom.h>
19 #include <asm/machdep.h>
20 #include <asm/io.h>
21 #include <asm/sections.h>
22 #include <asm/smu.h>
23 
24 #include "windfarm.h"
25 
26 #define VERSION "0.2"
27 
28 #undef DEBUG
29 
30 #ifdef DEBUG
31 #define DBG(args...) printk(args)
32 #else
33 #define DBG(args...) do { } while(0)
34 #endif
35 
36 /*
37  * Various SMU "partitions" calibration objects for which we
38  * keep pointers here for use by bits & pieces of the driver
39  */
40 static struct smu_sdbp_cpuvcp *cpuvcp;
41 static int cpuvcp_version;
42 static struct smu_sdbp_cpudiode *cpudiode;
43 static struct smu_sdbp_slotspow *slotspow;
44 static u8 *debugswitches;
45 
46 /*
47  * SMU basic sensors objects
48  */
49 
50 static LIST_HEAD(smu_ads);
51 
52 struct smu_ad_sensor {
53  struct list_head link;
54  u32 reg; /* index in SMU */
55  struct wf_sensor sens;
56 };
57 #define to_smu_ads(c) container_of(c, struct smu_ad_sensor, sens)
58 
59 static void smu_ads_release(struct wf_sensor *sr)
60 {
61  struct smu_ad_sensor *ads = to_smu_ads(sr);
62 
63  kfree(ads);
64 }
65 
66 static int smu_read_adc(u8 id, s32 *value)
67 {
68  struct smu_simple_cmd cmd;
70  int rc;
71 
73  smu_done_complete, &comp, id);
74  if (rc)
75  return rc;
76  wait_for_completion(&comp);
77  if (cmd.cmd.status != 0)
78  return cmd.cmd.status;
79  if (cmd.cmd.reply_len != 2) {
80  printk(KERN_ERR "winfarm: read ADC 0x%x returned %d bytes !\n",
81  id, cmd.cmd.reply_len);
82  return -EIO;
83  }
84  *value = *((u16 *)cmd.buffer);
85  return 0;
86 }
87 
88 static int smu_cputemp_get(struct wf_sensor *sr, s32 *value)
89 {
90  struct smu_ad_sensor *ads = to_smu_ads(sr);
91  int rc;
92  s32 val;
93  s64 scaled;
94 
95  rc = smu_read_adc(ads->reg, &val);
96  if (rc) {
97  printk(KERN_ERR "windfarm: read CPU temp failed, err %d\n",
98  rc);
99  return rc;
100  }
101 
102  /* Ok, we have to scale & adjust, taking units into account */
103  scaled = (s64)(((u64)val) * (u64)cpudiode->m_value);
104  scaled >>= 3;
105  scaled += ((s64)cpudiode->b_value) << 9;
106  *value = (s32)(scaled << 1);
107 
108  return 0;
109 }
110 
111 static int smu_cpuamp_get(struct wf_sensor *sr, s32 *value)
112 {
113  struct smu_ad_sensor *ads = to_smu_ads(sr);
114  s32 val, scaled;
115  int rc;
116 
117  rc = smu_read_adc(ads->reg, &val);
118  if (rc) {
119  printk(KERN_ERR "windfarm: read CPU current failed, err %d\n",
120  rc);
121  return rc;
122  }
123 
124  /* Ok, we have to scale & adjust, taking units into account */
125  scaled = (s32)(val * (u32)cpuvcp->curr_scale);
126  scaled += (s32)cpuvcp->curr_offset;
127  *value = scaled << 4;
128 
129  return 0;
130 }
131 
132 static int smu_cpuvolt_get(struct wf_sensor *sr, s32 *value)
133 {
134  struct smu_ad_sensor *ads = to_smu_ads(sr);
135  s32 val, scaled;
136  int rc;
137 
138  rc = smu_read_adc(ads->reg, &val);
139  if (rc) {
140  printk(KERN_ERR "windfarm: read CPU voltage failed, err %d\n",
141  rc);
142  return rc;
143  }
144 
145  /* Ok, we have to scale & adjust, taking units into account */
146  scaled = (s32)(val * (u32)cpuvcp->volt_scale);
147  scaled += (s32)cpuvcp->volt_offset;
148  *value = scaled << 4;
149 
150  return 0;
151 }
152 
153 static int smu_slotspow_get(struct wf_sensor *sr, s32 *value)
154 {
155  struct smu_ad_sensor *ads = to_smu_ads(sr);
156  s32 val, scaled;
157  int rc;
158 
159  rc = smu_read_adc(ads->reg, &val);
160  if (rc) {
161  printk(KERN_ERR "windfarm: read slots power failed, err %d\n",
162  rc);
163  return rc;
164  }
165 
166  /* Ok, we have to scale & adjust, taking units into account */
167  scaled = (s32)(val * (u32)slotspow->pow_scale);
168  scaled += (s32)slotspow->pow_offset;
169  *value = scaled << 4;
170 
171  return 0;
172 }
173 
174 
175 static struct wf_sensor_ops smu_cputemp_ops = {
176  .get_value = smu_cputemp_get,
177  .release = smu_ads_release,
178  .owner = THIS_MODULE,
179 };
180 static struct wf_sensor_ops smu_cpuamp_ops = {
181  .get_value = smu_cpuamp_get,
182  .release = smu_ads_release,
183  .owner = THIS_MODULE,
184 };
185 static struct wf_sensor_ops smu_cpuvolt_ops = {
186  .get_value = smu_cpuvolt_get,
187  .release = smu_ads_release,
188  .owner = THIS_MODULE,
189 };
190 static struct wf_sensor_ops smu_slotspow_ops = {
191  .get_value = smu_slotspow_get,
192  .release = smu_ads_release,
193  .owner = THIS_MODULE,
194 };
195 
196 
197 static struct smu_ad_sensor *smu_ads_create(struct device_node *node)
198 {
199  struct smu_ad_sensor *ads;
200  const char *c, *l;
201  const u32 *v;
202 
203  ads = kmalloc(sizeof(struct smu_ad_sensor), GFP_KERNEL);
204  if (ads == NULL)
205  return NULL;
206  c = of_get_property(node, "device_type", NULL);
207  l = of_get_property(node, "location", NULL);
208  if (c == NULL || l == NULL)
209  goto fail;
210 
211  /* We currently pick the sensors based on the OF name and location
212  * properties, while Darwin uses the sensor-id's.
213  * The problem with the IDs is that they are model specific while it
214  * looks like apple has been doing a reasonably good job at keeping
215  * the names and locations consistents so I'll stick with the names
216  * and locations for now.
217  */
218  if (!strcmp(c, "temp-sensor") &&
219  !strcmp(l, "CPU T-Diode")) {
220  ads->sens.ops = &smu_cputemp_ops;
221  ads->sens.name = "cpu-temp";
222  if (cpudiode == NULL) {
223  DBG("wf: cpudiode partition (%02x) not found\n",
225  goto fail;
226  }
227  } else if (!strcmp(c, "current-sensor") &&
228  !strcmp(l, "CPU Current")) {
229  ads->sens.ops = &smu_cpuamp_ops;
230  ads->sens.name = "cpu-current";
231  if (cpuvcp == NULL) {
232  DBG("wf: cpuvcp partition (%02x) not found\n",
234  goto fail;
235  }
236  } else if (!strcmp(c, "voltage-sensor") &&
237  !strcmp(l, "CPU Voltage")) {
238  ads->sens.ops = &smu_cpuvolt_ops;
239  ads->sens.name = "cpu-voltage";
240  if (cpuvcp == NULL) {
241  DBG("wf: cpuvcp partition (%02x) not found\n",
243  goto fail;
244  }
245  } else if (!strcmp(c, "power-sensor") &&
246  !strcmp(l, "Slots Power")) {
247  ads->sens.ops = &smu_slotspow_ops;
248  ads->sens.name = "slots-power";
249  if (slotspow == NULL) {
250  DBG("wf: slotspow partition (%02x) not found\n",
252  goto fail;
253  }
254  } else
255  goto fail;
256 
257  v = of_get_property(node, "reg", NULL);
258  if (v == NULL)
259  goto fail;
260  ads->reg = *v;
261 
262  if (wf_register_sensor(&ads->sens))
263  goto fail;
264  return ads;
265  fail:
266  kfree(ads);
267  return NULL;
268 }
269 
270 /*
271  * SMU Power combo sensor object
272  */
273 
275  struct list_head link;
276  struct wf_sensor *volts;
277  struct wf_sensor *amps;
278  int fake_volts : 1;
279  int quadratic : 1;
280  struct wf_sensor sens;
281 };
282 #define to_smu_cpu_power(c) container_of(c, struct smu_cpu_power_sensor, sens)
283 
284 static struct smu_cpu_power_sensor *smu_cpu_power;
285 
286 static void smu_cpu_power_release(struct wf_sensor *sr)
287 {
288  struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
289 
290  if (pow->volts)
291  wf_put_sensor(pow->volts);
292  if (pow->amps)
293  wf_put_sensor(pow->amps);
294  kfree(pow);
295 }
296 
297 static int smu_cpu_power_get(struct wf_sensor *sr, s32 *value)
298 {
299  struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
300  s32 volts, amps, power;
301  u64 tmps, tmpa, tmpb;
302  int rc;
303 
304  rc = pow->amps->ops->get_value(pow->amps, &amps);
305  if (rc)
306  return rc;
307 
308  if (pow->fake_volts) {
309  *value = amps * 12 - 0x30000;
310  return 0;
311  }
312 
313  rc = pow->volts->ops->get_value(pow->volts, &volts);
314  if (rc)
315  return rc;
316 
317  power = (s32)((((u64)volts) * ((u64)amps)) >> 16);
318  if (!pow->quadratic) {
319  *value = power;
320  return 0;
321  }
322  tmps = (((u64)power) * ((u64)power)) >> 16;
323  tmpa = ((u64)cpuvcp->power_quads[0]) * tmps;
324  tmpb = ((u64)cpuvcp->power_quads[1]) * ((u64)power);
325  *value = (tmpa >> 28) + (tmpb >> 28) + (cpuvcp->power_quads[2] >> 12);
326 
327  return 0;
328 }
329 
330 static struct wf_sensor_ops smu_cpu_power_ops = {
331  .get_value = smu_cpu_power_get,
332  .release = smu_cpu_power_release,
333  .owner = THIS_MODULE,
334 };
335 
336 
337 static struct smu_cpu_power_sensor *
338 smu_cpu_power_create(struct wf_sensor *volts, struct wf_sensor *amps)
339 {
340  struct smu_cpu_power_sensor *pow;
341 
342  pow = kmalloc(sizeof(struct smu_cpu_power_sensor), GFP_KERNEL);
343  if (pow == NULL)
344  return NULL;
345  pow->sens.ops = &smu_cpu_power_ops;
346  pow->sens.name = "cpu-power";
347 
348  wf_get_sensor(volts);
349  pow->volts = volts;
350  wf_get_sensor(amps);
351  pow->amps = amps;
352 
353  /* Some early machines need a faked voltage */
354  if (debugswitches && ((*debugswitches) & 0x80)) {
355  printk(KERN_INFO "windfarm: CPU Power sensor using faked"
356  " voltage !\n");
357  pow->fake_volts = 1;
358  } else
359  pow->fake_volts = 0;
360 
361  /* Try to use quadratic transforms on PowerMac8,1 and 9,1 for now,
362  * I yet have to figure out what's up with 8,2 and will have to
363  * adjust for later, unless we can 100% trust the SDB partition...
364  */
365  if ((of_machine_is_compatible("PowerMac8,1") ||
366  of_machine_is_compatible("PowerMac8,2") ||
367  of_machine_is_compatible("PowerMac9,1")) &&
368  cpuvcp_version >= 2) {
369  pow->quadratic = 1;
370  DBG("windfarm: CPU Power using quadratic transform\n");
371  } else
372  pow->quadratic = 0;
373 
374  if (wf_register_sensor(&pow->sens))
375  goto fail;
376  return pow;
377  fail:
378  kfree(pow);
379  return NULL;
380 }
381 
382 static void smu_fetch_param_partitions(void)
383 {
384  const struct smu_sdbp_header *hdr;
385 
386  /* Get CPU voltage/current/power calibration data */
388  if (hdr != NULL) {
389  cpuvcp = (struct smu_sdbp_cpuvcp *)&hdr[1];
390  /* Keep version around */
391  cpuvcp_version = hdr->version;
392  }
393 
394  /* Get CPU diode calibration data */
396  if (hdr != NULL)
397  cpudiode = (struct smu_sdbp_cpudiode *)&hdr[1];
398 
399  /* Get slots power calibration data if any */
401  if (hdr != NULL)
402  slotspow = (struct smu_sdbp_slotspow *)&hdr[1];
403 
404  /* Get debug switches if any */
406  if (hdr != NULL)
407  debugswitches = (u8 *)&hdr[1];
408 }
409 
410 static int __init smu_sensors_init(void)
411 {
412  struct device_node *smu, *sensors, *s;
413  struct smu_ad_sensor *volt_sensor = NULL, *curr_sensor = NULL;
414 
415  if (!smu_present())
416  return -ENODEV;
417 
418  /* Get parameters partitions */
419  smu_fetch_param_partitions();
420 
421  smu = of_find_node_by_type(NULL, "smu");
422  if (smu == NULL)
423  return -ENODEV;
424 
425  /* Look for sensors subdir */
426  for (sensors = NULL;
427  (sensors = of_get_next_child(smu, sensors)) != NULL;)
428  if (!strcmp(sensors->name, "sensors"))
429  break;
430 
431  of_node_put(smu);
432 
433  /* Create basic sensors */
434  for (s = NULL;
435  sensors && (s = of_get_next_child(sensors, s)) != NULL;) {
436  struct smu_ad_sensor *ads;
437 
438  ads = smu_ads_create(s);
439  if (ads == NULL)
440  continue;
441  list_add(&ads->link, &smu_ads);
442  /* keep track of cpu voltage & current */
443  if (!strcmp(ads->sens.name, "cpu-voltage"))
444  volt_sensor = ads;
445  else if (!strcmp(ads->sens.name, "cpu-current"))
446  curr_sensor = ads;
447  }
448 
449  of_node_put(sensors);
450 
451  /* Create CPU power sensor if possible */
452  if (volt_sensor && curr_sensor)
453  smu_cpu_power = smu_cpu_power_create(&volt_sensor->sens,
454  &curr_sensor->sens);
455 
456  return 0;
457 }
458 
459 static void __exit smu_sensors_exit(void)
460 {
461  struct smu_ad_sensor *ads;
462 
463  /* dispose of power sensor */
464  if (smu_cpu_power)
465  wf_unregister_sensor(&smu_cpu_power->sens);
466 
467  /* dispose of basic sensors */
468  while (!list_empty(&smu_ads)) {
469  ads = list_entry(smu_ads.next, struct smu_ad_sensor, link);
470  list_del(&ads->link);
471  wf_unregister_sensor(&ads->sens);
472  }
473 }
474 
475 
476 module_init(smu_sensors_init);
477 module_exit(smu_sensors_exit);
478 
479 MODULE_AUTHOR("Benjamin Herrenschmidt <[email protected]>");
480 MODULE_DESCRIPTION("SMU sensor objects for PowerMacs thermal control");
481 MODULE_LICENSE("GPL");
482