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/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 */
40static struct smu_sdbp_cpuvcp *cpuvcp;
41static int  cpuvcp_version;
42static struct smu_sdbp_cpudiode *cpudiode;
43static struct smu_sdbp_slotspow *slotspow;
44static u8 *debugswitches;
45
46/*
47 * SMU basic sensors objects
48 */
49
50static LIST_HEAD(smu_ads);
51
52struct 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
59static 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
66static 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
88static 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
111static 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
132static 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
153static 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
175static struct wf_sensor_ops smu_cputemp_ops = {
176	.get_value	= smu_cputemp_get,
177	.release	= smu_ads_release,
178	.owner		= THIS_MODULE,
179};
180static struct wf_sensor_ops smu_cpuamp_ops = {
181	.get_value	= smu_cpuamp_get,
182	.release	= smu_ads_release,
183	.owner		= THIS_MODULE,
184};
185static struct wf_sensor_ops smu_cpuvolt_ops = {
186	.get_value	= smu_cpuvolt_get,
187	.release	= smu_ads_release,
188	.owner		= THIS_MODULE,
189};
190static 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
197static 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",
224			    SMU_SDB_CPUDIODE_ID);
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",
233			    SMU_SDB_CPUVCP_ID);
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",
242			    SMU_SDB_CPUVCP_ID);
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",
251			    SMU_SDB_SLOTSPOW_ID);
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
274struct smu_cpu_power_sensor {
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
284static struct smu_cpu_power_sensor *smu_cpu_power;
285
286static 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
297static 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
330static 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
337static struct smu_cpu_power_sensor *
338smu_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
382static void smu_fetch_param_partitions(void)
383{
384	const struct smu_sdbp_header *hdr;
385
386	/* Get CPU voltage/current/power calibration data */
387	hdr = smu_get_sdb_partition(SMU_SDB_CPUVCP_ID, NULL);
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 */
395	hdr = smu_get_sdb_partition(SMU_SDB_CPUDIODE_ID, NULL);
396	if (hdr != NULL)
397		cpudiode = (struct smu_sdbp_cpudiode *)&hdr[1];
398
399	/* Get slots power calibration data if any */
400	hdr = smu_get_sdb_partition(SMU_SDB_SLOTSPOW_ID, NULL);
401	if (hdr != NULL)
402		slotspow = (struct smu_sdbp_slotspow *)&hdr[1];
403
404	/* Get debug switches if any */
405	hdr = smu_get_sdb_partition(SMU_SDB_DEBUG_SWITCHES_ID, NULL);
406	if (hdr != NULL)
407		debugswitches = (u8 *)&hdr[1];
408}
409
410static 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
459static 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
476module_init(smu_sensors_init);
477module_exit(smu_sensors_exit);
478
479MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
480MODULE_DESCRIPTION("SMU sensor objects for PowerMacs thermal control");
481MODULE_LICENSE("GPL");
482
483