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 <linux/of.h>
18 
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;
69 	DECLARE_COMPLETION_ONSTACK(comp);
70 	int rc;
71 
72 	rc = smu_queue_simple(&cmd, SMU_CMD_READ_ADC, 1,
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 const 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 const 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 const 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 const 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 *l;
201 	const u32 *v;
202 
203 	ads = kmalloc(sizeof(struct smu_ad_sensor), GFP_KERNEL);
204 	if (ads == NULL)
205 		return NULL;
206 	l = of_get_property(node, "location", NULL);
207 	if (l == NULL)
208 		goto fail;
209 
210 	/* We currently pick the sensors based on the OF name and location
211 	 * properties, while Darwin uses the sensor-id's.
212 	 * The problem with the IDs is that they are model specific while it
213 	 * looks like apple has been doing a reasonably good job at keeping
214 	 * the names and locations consistents so I'll stick with the names
215 	 * and locations for now.
216 	 */
217 	if (of_node_is_type(node, "temp-sensor") &&
218 	    !strcmp(l, "CPU T-Diode")) {
219 		ads->sens.ops = &smu_cputemp_ops;
220 		ads->sens.name = "cpu-temp";
221 		if (cpudiode == NULL) {
222 			DBG("wf: cpudiode partition (%02x) not found\n",
223 			    SMU_SDB_CPUDIODE_ID);
224 			goto fail;
225 		}
226 	} else if (of_node_is_type(node, "current-sensor") &&
227 		   !strcmp(l, "CPU Current")) {
228 		ads->sens.ops = &smu_cpuamp_ops;
229 		ads->sens.name = "cpu-current";
230 		if (cpuvcp == NULL) {
231 			DBG("wf: cpuvcp partition (%02x) not found\n",
232 			    SMU_SDB_CPUVCP_ID);
233 			goto fail;
234 		}
235 	} else if (of_node_is_type(node, "voltage-sensor") &&
236 		   !strcmp(l, "CPU Voltage")) {
237 		ads->sens.ops = &smu_cpuvolt_ops;
238 		ads->sens.name = "cpu-voltage";
239 		if (cpuvcp == NULL) {
240 			DBG("wf: cpuvcp partition (%02x) not found\n",
241 			    SMU_SDB_CPUVCP_ID);
242 			goto fail;
243 		}
244 	} else if (of_node_is_type(node, "power-sensor") &&
245 		   !strcmp(l, "Slots Power")) {
246 		ads->sens.ops = &smu_slotspow_ops;
247 		ads->sens.name = "slots-power";
248 		if (slotspow == NULL) {
249 			DBG("wf: slotspow partition (%02x) not found\n",
250 			    SMU_SDB_SLOTSPOW_ID);
251 			goto fail;
252 		}
253 	} else
254 		goto fail;
255 
256 	v = of_get_property(node, "reg", NULL);
257 	if (v == NULL)
258 		goto fail;
259 	ads->reg = *v;
260 
261 	if (wf_register_sensor(&ads->sens))
262 		goto fail;
263 	return ads;
264  fail:
265 	kfree(ads);
266 	return NULL;
267 }
268 
269 /*
270  * SMU Power combo sensor object
271  */
272 
273 struct smu_cpu_power_sensor {
274 	struct list_head	link;
275 	struct wf_sensor	*volts;
276 	struct wf_sensor	*amps;
277 	int			fake_volts : 1;
278 	int			quadratic : 1;
279 	struct wf_sensor	sens;
280 };
281 #define to_smu_cpu_power(c) container_of(c, struct smu_cpu_power_sensor, sens)
282 
283 static struct smu_cpu_power_sensor *smu_cpu_power;
284 
285 static void smu_cpu_power_release(struct wf_sensor *sr)
286 {
287 	struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
288 
289 	if (pow->volts)
290 		wf_put_sensor(pow->volts);
291 	if (pow->amps)
292 		wf_put_sensor(pow->amps);
293 	kfree(pow);
294 }
295 
296 static int smu_cpu_power_get(struct wf_sensor *sr, s32 *value)
297 {
298 	struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
299 	s32 volts, amps, power;
300 	u64 tmps, tmpa, tmpb;
301 	int rc;
302 
303 	rc = pow->amps->ops->get_value(pow->amps, &amps);
304 	if (rc)
305 		return rc;
306 
307 	if (pow->fake_volts) {
308 		*value = amps * 12 - 0x30000;
309 		return 0;
310 	}
311 
312 	rc = pow->volts->ops->get_value(pow->volts, &volts);
313 	if (rc)
314 		return rc;
315 
316 	power = (s32)((((u64)volts) * ((u64)amps)) >> 16);
317 	if (!pow->quadratic) {
318 		*value = power;
319 		return 0;
320 	}
321 	tmps = (((u64)power) * ((u64)power)) >> 16;
322 	tmpa = ((u64)cpuvcp->power_quads[0]) * tmps;
323 	tmpb = ((u64)cpuvcp->power_quads[1]) * ((u64)power);
324 	*value = (tmpa >> 28) + (tmpb >> 28) + (cpuvcp->power_quads[2] >> 12);
325 
326 	return 0;
327 }
328 
329 static const struct wf_sensor_ops smu_cpu_power_ops = {
330 	.get_value	= smu_cpu_power_get,
331 	.release	= smu_cpu_power_release,
332 	.owner		= THIS_MODULE,
333 };
334 
335 
336 static struct smu_cpu_power_sensor *
337 smu_cpu_power_create(struct wf_sensor *volts, struct wf_sensor *amps)
338 {
339 	struct smu_cpu_power_sensor *pow;
340 
341 	pow = kmalloc(sizeof(struct smu_cpu_power_sensor), GFP_KERNEL);
342 	if (pow == NULL)
343 		return NULL;
344 	pow->sens.ops = &smu_cpu_power_ops;
345 	pow->sens.name = "cpu-power";
346 
347 	wf_get_sensor(volts);
348 	pow->volts = volts;
349 	wf_get_sensor(amps);
350 	pow->amps = amps;
351 
352 	/* Some early machines need a faked voltage */
353 	if (debugswitches && ((*debugswitches) & 0x80)) {
354 		printk(KERN_INFO "windfarm: CPU Power sensor using faked"
355 		       " voltage !\n");
356 		pow->fake_volts = 1;
357 	} else
358 		pow->fake_volts = 0;
359 
360 	/* Try to use quadratic transforms on PowerMac8,1 and 9,1 for now,
361 	 * I yet have to figure out what's up with 8,2 and will have to
362 	 * adjust for later, unless we can 100% trust the SDB partition...
363 	 */
364 	if ((of_machine_is_compatible("PowerMac8,1") ||
365 	     of_machine_is_compatible("PowerMac8,2") ||
366 	     of_machine_is_compatible("PowerMac9,1")) &&
367 	    cpuvcp_version >= 2) {
368 		pow->quadratic = 1;
369 		DBG("windfarm: CPU Power using quadratic transform\n");
370 	} else
371 		pow->quadratic = 0;
372 
373 	if (wf_register_sensor(&pow->sens))
374 		goto fail;
375 	return pow;
376  fail:
377 	kfree(pow);
378 	return NULL;
379 }
380 
381 static void smu_fetch_param_partitions(void)
382 {
383 	const struct smu_sdbp_header *hdr;
384 
385 	/* Get CPU voltage/current/power calibration data */
386 	hdr = smu_get_sdb_partition(SMU_SDB_CPUVCP_ID, NULL);
387 	if (hdr != NULL) {
388 		cpuvcp = (struct smu_sdbp_cpuvcp *)&hdr[1];
389 		/* Keep version around */
390 		cpuvcp_version = hdr->version;
391 	}
392 
393 	/* Get CPU diode calibration data */
394 	hdr = smu_get_sdb_partition(SMU_SDB_CPUDIODE_ID, NULL);
395 	if (hdr != NULL)
396 		cpudiode = (struct smu_sdbp_cpudiode *)&hdr[1];
397 
398 	/* Get slots power calibration data if any */
399 	hdr = smu_get_sdb_partition(SMU_SDB_SLOTSPOW_ID, NULL);
400 	if (hdr != NULL)
401 		slotspow = (struct smu_sdbp_slotspow *)&hdr[1];
402 
403 	/* Get debug switches if any */
404 	hdr = smu_get_sdb_partition(SMU_SDB_DEBUG_SWITCHES_ID, NULL);
405 	if (hdr != NULL)
406 		debugswitches = (u8 *)&hdr[1];
407 }
408 
409 static int __init smu_sensors_init(void)
410 {
411 	struct device_node *smu, *sensors, *s;
412 	struct smu_ad_sensor *volt_sensor = NULL, *curr_sensor = NULL;
413 
414 	if (!smu_present())
415 		return -ENODEV;
416 
417 	/* Get parameters partitions */
418 	smu_fetch_param_partitions();
419 
420 	smu = of_find_node_by_type(NULL, "smu");
421 	if (smu == NULL)
422 		return -ENODEV;
423 
424 	/* Look for sensors subdir */
425 	for_each_child_of_node(smu, sensors)
426 		if (of_node_name_eq(sensors, "sensors"))
427 			break;
428 
429 	of_node_put(smu);
430 
431 	/* Create basic sensors */
432 	for (s = NULL;
433 	     sensors && (s = of_get_next_child(sensors, s)) != NULL;) {
434 		struct smu_ad_sensor *ads;
435 
436 		ads = smu_ads_create(s);
437 		if (ads == NULL)
438 			continue;
439 		list_add(&ads->link, &smu_ads);
440 		/* keep track of cpu voltage & current */
441 		if (!strcmp(ads->sens.name, "cpu-voltage"))
442 			volt_sensor = ads;
443 		else if (!strcmp(ads->sens.name, "cpu-current"))
444 			curr_sensor = ads;
445 	}
446 
447 	of_node_put(sensors);
448 
449 	/* Create CPU power sensor if possible */
450 	if (volt_sensor && curr_sensor)
451 		smu_cpu_power = smu_cpu_power_create(&volt_sensor->sens,
452 						     &curr_sensor->sens);
453 
454 	return 0;
455 }
456 
457 static void __exit smu_sensors_exit(void)
458 {
459 	struct smu_ad_sensor *ads;
460 
461 	/* dispose of power sensor */
462 	if (smu_cpu_power)
463 		wf_unregister_sensor(&smu_cpu_power->sens);
464 
465 	/* dispose of basic sensors */
466 	while (!list_empty(&smu_ads)) {
467 		ads = list_entry(smu_ads.next, struct smu_ad_sensor, link);
468 		list_del(&ads->link);
469 		wf_unregister_sensor(&ads->sens);
470 	}
471 }
472 
473 
474 module_init(smu_sensors_init);
475 module_exit(smu_sensors_exit);
476 
477 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
478 MODULE_DESCRIPTION("SMU sensor objects for PowerMacs thermal control");
479 MODULE_LICENSE("GPL");
480 
481