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 
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 
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 
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 
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 
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 
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 
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 
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 
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, &amps);
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 *
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 
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 
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 
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