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