1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Windfarm PowerMac thermal control. SMU based sensors
4 *
5 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6 * <benh@kernel.crashing.org>
7 */
8
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/wait.h>
16 #include <linux/completion.h>
17 #include <asm/prom.h>
18 #include <asm/machdep.h>
19 #include <asm/io.h>
20 #include <asm/sections.h>
21 #include <asm/smu.h>
22
23 #include "windfarm.h"
24
25 #define VERSION "0.2"
26
27 #undef DEBUG
28
29 #ifdef DEBUG
30 #define DBG(args...) printk(args)
31 #else
32 #define DBG(args...) do { } while(0)
33 #endif
34
35 /*
36 * Various SMU "partitions" calibration objects for which we
37 * keep pointers here for use by bits & pieces of the driver
38 */
39 static struct smu_sdbp_cpuvcp *cpuvcp;
40 static int cpuvcp_version;
41 static struct smu_sdbp_cpudiode *cpudiode;
42 static struct smu_sdbp_slotspow *slotspow;
43 static u8 *debugswitches;
44
45 /*
46 * SMU basic sensors objects
47 */
48
49 static LIST_HEAD(smu_ads);
50
51 struct smu_ad_sensor {
52 struct list_head link;
53 u32 reg; /* index in SMU */
54 struct wf_sensor sens;
55 };
56 #define to_smu_ads(c) container_of(c, struct smu_ad_sensor, sens)
57
smu_ads_release(struct wf_sensor * sr)58 static void smu_ads_release(struct wf_sensor *sr)
59 {
60 struct smu_ad_sensor *ads = to_smu_ads(sr);
61
62 kfree(ads);
63 }
64
smu_read_adc(u8 id,s32 * value)65 static int smu_read_adc(u8 id, s32 *value)
66 {
67 struct smu_simple_cmd cmd;
68 DECLARE_COMPLETION_ONSTACK(comp);
69 int rc;
70
71 rc = smu_queue_simple(&cmd, SMU_CMD_READ_ADC, 1,
72 smu_done_complete, &comp, id);
73 if (rc)
74 return rc;
75 wait_for_completion(&comp);
76 if (cmd.cmd.status != 0)
77 return cmd.cmd.status;
78 if (cmd.cmd.reply_len != 2) {
79 printk(KERN_ERR "winfarm: read ADC 0x%x returned %d bytes !\n",
80 id, cmd.cmd.reply_len);
81 return -EIO;
82 }
83 *value = *((u16 *)cmd.buffer);
84 return 0;
85 }
86
smu_cputemp_get(struct wf_sensor * sr,s32 * value)87 static int smu_cputemp_get(struct wf_sensor *sr, s32 *value)
88 {
89 struct smu_ad_sensor *ads = to_smu_ads(sr);
90 int rc;
91 s32 val;
92 s64 scaled;
93
94 rc = smu_read_adc(ads->reg, &val);
95 if (rc) {
96 printk(KERN_ERR "windfarm: read CPU temp failed, err %d\n",
97 rc);
98 return rc;
99 }
100
101 /* Ok, we have to scale & adjust, taking units into account */
102 scaled = (s64)(((u64)val) * (u64)cpudiode->m_value);
103 scaled >>= 3;
104 scaled += ((s64)cpudiode->b_value) << 9;
105 *value = (s32)(scaled << 1);
106
107 return 0;
108 }
109
smu_cpuamp_get(struct wf_sensor * sr,s32 * value)110 static int smu_cpuamp_get(struct wf_sensor *sr, s32 *value)
111 {
112 struct smu_ad_sensor *ads = to_smu_ads(sr);
113 s32 val, scaled;
114 int rc;
115
116 rc = smu_read_adc(ads->reg, &val);
117 if (rc) {
118 printk(KERN_ERR "windfarm: read CPU current failed, err %d\n",
119 rc);
120 return rc;
121 }
122
123 /* Ok, we have to scale & adjust, taking units into account */
124 scaled = (s32)(val * (u32)cpuvcp->curr_scale);
125 scaled += (s32)cpuvcp->curr_offset;
126 *value = scaled << 4;
127
128 return 0;
129 }
130
smu_cpuvolt_get(struct wf_sensor * sr,s32 * value)131 static int smu_cpuvolt_get(struct wf_sensor *sr, s32 *value)
132 {
133 struct smu_ad_sensor *ads = to_smu_ads(sr);
134 s32 val, scaled;
135 int rc;
136
137 rc = smu_read_adc(ads->reg, &val);
138 if (rc) {
139 printk(KERN_ERR "windfarm: read CPU voltage failed, err %d\n",
140 rc);
141 return rc;
142 }
143
144 /* Ok, we have to scale & adjust, taking units into account */
145 scaled = (s32)(val * (u32)cpuvcp->volt_scale);
146 scaled += (s32)cpuvcp->volt_offset;
147 *value = scaled << 4;
148
149 return 0;
150 }
151
smu_slotspow_get(struct wf_sensor * sr,s32 * value)152 static int smu_slotspow_get(struct wf_sensor *sr, s32 *value)
153 {
154 struct smu_ad_sensor *ads = to_smu_ads(sr);
155 s32 val, scaled;
156 int rc;
157
158 rc = smu_read_adc(ads->reg, &val);
159 if (rc) {
160 printk(KERN_ERR "windfarm: read slots power failed, err %d\n",
161 rc);
162 return rc;
163 }
164
165 /* Ok, we have to scale & adjust, taking units into account */
166 scaled = (s32)(val * (u32)slotspow->pow_scale);
167 scaled += (s32)slotspow->pow_offset;
168 *value = scaled << 4;
169
170 return 0;
171 }
172
173
174 static const struct wf_sensor_ops smu_cputemp_ops = {
175 .get_value = smu_cputemp_get,
176 .release = smu_ads_release,
177 .owner = THIS_MODULE,
178 };
179 static const struct wf_sensor_ops smu_cpuamp_ops = {
180 .get_value = smu_cpuamp_get,
181 .release = smu_ads_release,
182 .owner = THIS_MODULE,
183 };
184 static const struct wf_sensor_ops smu_cpuvolt_ops = {
185 .get_value = smu_cpuvolt_get,
186 .release = smu_ads_release,
187 .owner = THIS_MODULE,
188 };
189 static const struct wf_sensor_ops smu_slotspow_ops = {
190 .get_value = smu_slotspow_get,
191 .release = smu_ads_release,
192 .owner = THIS_MODULE,
193 };
194
195
smu_ads_create(struct device_node * node)196 static struct smu_ad_sensor *smu_ads_create(struct device_node *node)
197 {
198 struct smu_ad_sensor *ads;
199 const char *l;
200 const u32 *v;
201
202 ads = kmalloc(sizeof(struct smu_ad_sensor), GFP_KERNEL);
203 if (ads == NULL)
204 return NULL;
205 l = of_get_property(node, "location", NULL);
206 if (l == NULL)
207 goto fail;
208
209 /* We currently pick the sensors based on the OF name and location
210 * properties, while Darwin uses the sensor-id's.
211 * The problem with the IDs is that they are model specific while it
212 * looks like apple has been doing a reasonably good job at keeping
213 * the names and locations consistents so I'll stick with the names
214 * and locations for now.
215 */
216 if (of_node_is_type(node, "temp-sensor") &&
217 !strcmp(l, "CPU T-Diode")) {
218 ads->sens.ops = &smu_cputemp_ops;
219 ads->sens.name = "cpu-temp";
220 if (cpudiode == NULL) {
221 DBG("wf: cpudiode partition (%02x) not found\n",
222 SMU_SDB_CPUDIODE_ID);
223 goto fail;
224 }
225 } else if (of_node_is_type(node, "current-sensor") &&
226 !strcmp(l, "CPU Current")) {
227 ads->sens.ops = &smu_cpuamp_ops;
228 ads->sens.name = "cpu-current";
229 if (cpuvcp == NULL) {
230 DBG("wf: cpuvcp partition (%02x) not found\n",
231 SMU_SDB_CPUVCP_ID);
232 goto fail;
233 }
234 } else if (of_node_is_type(node, "voltage-sensor") &&
235 !strcmp(l, "CPU Voltage")) {
236 ads->sens.ops = &smu_cpuvolt_ops;
237 ads->sens.name = "cpu-voltage";
238 if (cpuvcp == NULL) {
239 DBG("wf: cpuvcp partition (%02x) not found\n",
240 SMU_SDB_CPUVCP_ID);
241 goto fail;
242 }
243 } else if (of_node_is_type(node, "power-sensor") &&
244 !strcmp(l, "Slots Power")) {
245 ads->sens.ops = &smu_slotspow_ops;
246 ads->sens.name = "slots-power";
247 if (slotspow == NULL) {
248 DBG("wf: slotspow partition (%02x) not found\n",
249 SMU_SDB_SLOTSPOW_ID);
250 goto fail;
251 }
252 } else
253 goto fail;
254
255 v = of_get_property(node, "reg", NULL);
256 if (v == NULL)
257 goto fail;
258 ads->reg = *v;
259
260 if (wf_register_sensor(&ads->sens))
261 goto fail;
262 return ads;
263 fail:
264 kfree(ads);
265 return NULL;
266 }
267
268 /*
269 * SMU Power combo sensor object
270 */
271
272 struct smu_cpu_power_sensor {
273 struct list_head link;
274 struct wf_sensor *volts;
275 struct wf_sensor *amps;
276 int fake_volts : 1;
277 int quadratic : 1;
278 struct wf_sensor sens;
279 };
280 #define to_smu_cpu_power(c) container_of(c, struct smu_cpu_power_sensor, sens)
281
282 static struct smu_cpu_power_sensor *smu_cpu_power;
283
smu_cpu_power_release(struct wf_sensor * sr)284 static void smu_cpu_power_release(struct wf_sensor *sr)
285 {
286 struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
287
288 if (pow->volts)
289 wf_put_sensor(pow->volts);
290 if (pow->amps)
291 wf_put_sensor(pow->amps);
292 kfree(pow);
293 }
294
smu_cpu_power_get(struct wf_sensor * sr,s32 * value)295 static int smu_cpu_power_get(struct wf_sensor *sr, s32 *value)
296 {
297 struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
298 s32 volts, amps, power;
299 u64 tmps, tmpa, tmpb;
300 int rc;
301
302 rc = pow->amps->ops->get_value(pow->amps, &s);
303 if (rc)
304 return rc;
305
306 if (pow->fake_volts) {
307 *value = amps * 12 - 0x30000;
308 return 0;
309 }
310
311 rc = pow->volts->ops->get_value(pow->volts, &volts);
312 if (rc)
313 return rc;
314
315 power = (s32)((((u64)volts) * ((u64)amps)) >> 16);
316 if (!pow->quadratic) {
317 *value = power;
318 return 0;
319 }
320 tmps = (((u64)power) * ((u64)power)) >> 16;
321 tmpa = ((u64)cpuvcp->power_quads[0]) * tmps;
322 tmpb = ((u64)cpuvcp->power_quads[1]) * ((u64)power);
323 *value = (tmpa >> 28) + (tmpb >> 28) + (cpuvcp->power_quads[2] >> 12);
324
325 return 0;
326 }
327
328 static const struct wf_sensor_ops smu_cpu_power_ops = {
329 .get_value = smu_cpu_power_get,
330 .release = smu_cpu_power_release,
331 .owner = THIS_MODULE,
332 };
333
334
335 static struct smu_cpu_power_sensor *
smu_cpu_power_create(struct wf_sensor * volts,struct wf_sensor * amps)336 smu_cpu_power_create(struct wf_sensor *volts, struct wf_sensor *amps)
337 {
338 struct smu_cpu_power_sensor *pow;
339
340 pow = kmalloc(sizeof(struct smu_cpu_power_sensor), GFP_KERNEL);
341 if (pow == NULL)
342 return NULL;
343 pow->sens.ops = &smu_cpu_power_ops;
344 pow->sens.name = "cpu-power";
345
346 wf_get_sensor(volts);
347 pow->volts = volts;
348 wf_get_sensor(amps);
349 pow->amps = amps;
350
351 /* Some early machines need a faked voltage */
352 if (debugswitches && ((*debugswitches) & 0x80)) {
353 printk(KERN_INFO "windfarm: CPU Power sensor using faked"
354 " voltage !\n");
355 pow->fake_volts = 1;
356 } else
357 pow->fake_volts = 0;
358
359 /* Try to use quadratic transforms on PowerMac8,1 and 9,1 for now,
360 * I yet have to figure out what's up with 8,2 and will have to
361 * adjust for later, unless we can 100% trust the SDB partition...
362 */
363 if ((of_machine_is_compatible("PowerMac8,1") ||
364 of_machine_is_compatible("PowerMac8,2") ||
365 of_machine_is_compatible("PowerMac9,1")) &&
366 cpuvcp_version >= 2) {
367 pow->quadratic = 1;
368 DBG("windfarm: CPU Power using quadratic transform\n");
369 } else
370 pow->quadratic = 0;
371
372 if (wf_register_sensor(&pow->sens))
373 goto fail;
374 return pow;
375 fail:
376 kfree(pow);
377 return NULL;
378 }
379
smu_fetch_param_partitions(void)380 static void smu_fetch_param_partitions(void)
381 {
382 const struct smu_sdbp_header *hdr;
383
384 /* Get CPU voltage/current/power calibration data */
385 hdr = smu_get_sdb_partition(SMU_SDB_CPUVCP_ID, NULL);
386 if (hdr != NULL) {
387 cpuvcp = (struct smu_sdbp_cpuvcp *)&hdr[1];
388 /* Keep version around */
389 cpuvcp_version = hdr->version;
390 }
391
392 /* Get CPU diode calibration data */
393 hdr = smu_get_sdb_partition(SMU_SDB_CPUDIODE_ID, NULL);
394 if (hdr != NULL)
395 cpudiode = (struct smu_sdbp_cpudiode *)&hdr[1];
396
397 /* Get slots power calibration data if any */
398 hdr = smu_get_sdb_partition(SMU_SDB_SLOTSPOW_ID, NULL);
399 if (hdr != NULL)
400 slotspow = (struct smu_sdbp_slotspow *)&hdr[1];
401
402 /* Get debug switches if any */
403 hdr = smu_get_sdb_partition(SMU_SDB_DEBUG_SWITCHES_ID, NULL);
404 if (hdr != NULL)
405 debugswitches = (u8 *)&hdr[1];
406 }
407
smu_sensors_init(void)408 static int __init smu_sensors_init(void)
409 {
410 struct device_node *smu, *sensors, *s;
411 struct smu_ad_sensor *volt_sensor = NULL, *curr_sensor = NULL;
412
413 if (!smu_present())
414 return -ENODEV;
415
416 /* Get parameters partitions */
417 smu_fetch_param_partitions();
418
419 smu = of_find_node_by_type(NULL, "smu");
420 if (smu == NULL)
421 return -ENODEV;
422
423 /* Look for sensors subdir */
424 for_each_child_of_node(smu, sensors)
425 if (of_node_name_eq(sensors, "sensors"))
426 break;
427
428 of_node_put(smu);
429
430 /* Create basic sensors */
431 for (s = NULL;
432 sensors && (s = of_get_next_child(sensors, s)) != NULL;) {
433 struct smu_ad_sensor *ads;
434
435 ads = smu_ads_create(s);
436 if (ads == NULL)
437 continue;
438 list_add(&ads->link, &smu_ads);
439 /* keep track of cpu voltage & current */
440 if (!strcmp(ads->sens.name, "cpu-voltage"))
441 volt_sensor = ads;
442 else if (!strcmp(ads->sens.name, "cpu-current"))
443 curr_sensor = ads;
444 }
445
446 of_node_put(sensors);
447
448 /* Create CPU power sensor if possible */
449 if (volt_sensor && curr_sensor)
450 smu_cpu_power = smu_cpu_power_create(&volt_sensor->sens,
451 &curr_sensor->sens);
452
453 return 0;
454 }
455
smu_sensors_exit(void)456 static void __exit smu_sensors_exit(void)
457 {
458 struct smu_ad_sensor *ads;
459
460 /* dispose of power sensor */
461 if (smu_cpu_power)
462 wf_unregister_sensor(&smu_cpu_power->sens);
463
464 /* dispose of basic sensors */
465 while (!list_empty(&smu_ads)) {
466 ads = list_entry(smu_ads.next, struct smu_ad_sensor, link);
467 list_del(&ads->link);
468 wf_unregister_sensor(&ads->sens);
469 }
470 }
471
472
473 module_init(smu_sensors_init);
474 module_exit(smu_sensors_exit);
475
476 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
477 MODULE_DESCRIPTION("SMU sensor objects for PowerMacs thermal control");
478 MODULE_LICENSE("GPL");
479
480