[go: nahoru, domu]
1/*
2 * Windfarm PowerMac thermal control.  SMU "satellite" controller sensors.
3 *
4 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
5 *
6 * Released under the terms of the GNU GPL v2.
7 */
8
9#include <linux/types.h>
10#include <linux/errno.h>
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/init.h>
14#include <linux/wait.h>
15#include <linux/i2c.h>
16#include <linux/mutex.h>
17#include <asm/prom.h>
18#include <asm/smu.h>
19#include <asm/pmac_low_i2c.h>
20
21#include "windfarm.h"
22
23#define VERSION "1.0"
24
25#define DEBUG
26
27#ifdef DEBUG
28#define DBG(args...)	printk(args)
29#else
30#define DBG(args...)	do { } while(0)
31#endif
32
33/* If the cache is older than 800ms we'll refetch it */
34#define MAX_AGE		msecs_to_jiffies(800)
35
36struct wf_sat {
37	struct kref		ref;
38	int			nr;
39	struct mutex		mutex;
40	unsigned long		last_read; /* jiffies when cache last updated */
41	u8			cache[16];
42	struct list_head	sensors;
43	struct i2c_client	*i2c;
44	struct device_node	*node;
45};
46
47static struct wf_sat *sats[2];
48
49struct wf_sat_sensor {
50	struct list_head	link;
51	int			index;
52	int			index2;		/* used for power sensors */
53	int			shift;
54	struct wf_sat		*sat;
55	struct wf_sensor 	sens;
56};
57
58#define wf_to_sat(c)	container_of(c, struct wf_sat_sensor, sens)
59
60struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
61						  unsigned int *size)
62{
63	struct wf_sat *sat;
64	int err;
65	unsigned int i, len;
66	u8 *buf;
67	u8 data[4];
68
69	/* TODO: Add the resulting partition to the device-tree */
70
71	if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
72		return NULL;
73
74	err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
75	if (err) {
76		printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
77		return NULL;
78	}
79
80	err = i2c_smbus_read_word_data(sat->i2c, 9);
81	if (err < 0) {
82		printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
83		return NULL;
84	}
85	len = err;
86	if (len == 0) {
87		printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
88		return NULL;
89	}
90
91	len = le16_to_cpu(len);
92	len = (len + 3) & ~3;
93	buf = kmalloc(len, GFP_KERNEL);
94	if (buf == NULL)
95		return NULL;
96
97	for (i = 0; i < len; i += 4) {
98		err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
99		if (err < 0) {
100			printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
101			       err);
102			goto fail;
103		}
104		buf[i] = data[1];
105		buf[i+1] = data[0];
106		buf[i+2] = data[3];
107		buf[i+3] = data[2];
108	}
109#ifdef DEBUG
110	DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
111	for (i = 0; i < len; ++i)
112		DBG(" %x", buf[i]);
113	DBG("\n");
114#endif
115
116	if (size)
117		*size = len;
118	return (struct smu_sdbp_header *) buf;
119
120 fail:
121	kfree(buf);
122	return NULL;
123}
124EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
125
126/* refresh the cache */
127static int wf_sat_read_cache(struct wf_sat *sat)
128{
129	int err;
130
131	err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
132	if (err < 0)
133		return err;
134	sat->last_read = jiffies;
135#ifdef LOTSA_DEBUG
136	{
137		int i;
138		DBG(KERN_DEBUG "wf_sat_get: data is");
139		for (i = 0; i < 16; ++i)
140			DBG(" %.2x", sat->cache[i]);
141		DBG("\n");
142	}
143#endif
144	return 0;
145}
146
147static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
148{
149	struct wf_sat_sensor *sens = wf_to_sat(sr);
150	struct wf_sat *sat = sens->sat;
151	int i, err;
152	s32 val;
153
154	if (sat->i2c == NULL)
155		return -ENODEV;
156
157	mutex_lock(&sat->mutex);
158	if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
159		err = wf_sat_read_cache(sat);
160		if (err)
161			goto fail;
162	}
163
164	i = sens->index * 2;
165	val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
166	if (sens->index2 >= 0) {
167		i = sens->index2 * 2;
168		/* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
169		val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
170	}
171
172	*value = val;
173	err = 0;
174
175 fail:
176	mutex_unlock(&sat->mutex);
177	return err;
178}
179
180static void wf_sat_release(struct kref *ref)
181{
182	struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
183
184	if (sat->nr >= 0)
185		sats[sat->nr] = NULL;
186	kfree(sat);
187}
188
189static void wf_sat_sensor_release(struct wf_sensor *sr)
190{
191	struct wf_sat_sensor *sens = wf_to_sat(sr);
192	struct wf_sat *sat = sens->sat;
193
194	kfree(sens);
195	kref_put(&sat->ref, wf_sat_release);
196}
197
198static struct wf_sensor_ops wf_sat_ops = {
199	.get_value	= wf_sat_sensor_get,
200	.release	= wf_sat_sensor_release,
201	.owner		= THIS_MODULE,
202};
203
204static int wf_sat_probe(struct i2c_client *client,
205			const struct i2c_device_id *id)
206{
207	struct device_node *dev = client->dev.of_node;
208	struct wf_sat *sat;
209	struct wf_sat_sensor *sens;
210	const u32 *reg;
211	const char *loc, *type;
212	u8 chip, core;
213	struct device_node *child;
214	int shift, cpu, index;
215	char *name;
216	int vsens[2], isens[2];
217
218	sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
219	if (sat == NULL)
220		return -ENOMEM;
221	sat->nr = -1;
222	sat->node = of_node_get(dev);
223	kref_init(&sat->ref);
224	mutex_init(&sat->mutex);
225	sat->i2c = client;
226	INIT_LIST_HEAD(&sat->sensors);
227	i2c_set_clientdata(client, sat);
228
229	vsens[0] = vsens[1] = -1;
230	isens[0] = isens[1] = -1;
231	child = NULL;
232	while ((child = of_get_next_child(dev, child)) != NULL) {
233		reg = of_get_property(child, "reg", NULL);
234		type = of_get_property(child, "device_type", NULL);
235		loc = of_get_property(child, "location", NULL);
236		if (reg == NULL || loc == NULL)
237			continue;
238
239		/* the cooked sensors are between 0x30 and 0x37 */
240		if (*reg < 0x30 || *reg > 0x37)
241			continue;
242		index = *reg - 0x30;
243
244		/* expect location to be CPU [AB][01] ... */
245		if (strncmp(loc, "CPU ", 4) != 0)
246			continue;
247		chip = loc[4] - 'A';
248		core = loc[5] - '0';
249		if (chip > 1 || core > 1) {
250			printk(KERN_ERR "wf_sat_create: don't understand "
251			       "location %s for %s\n", loc, child->full_name);
252			continue;
253		}
254		cpu = 2 * chip + core;
255		if (sat->nr < 0)
256			sat->nr = chip;
257		else if (sat->nr != chip) {
258			printk(KERN_ERR "wf_sat_create: can't cope with "
259			       "multiple CPU chips on one SAT (%s)\n", loc);
260			continue;
261		}
262
263		if (strcmp(type, "voltage-sensor") == 0) {
264			name = "cpu-voltage";
265			shift = 4;
266			vsens[core] = index;
267		} else if (strcmp(type, "current-sensor") == 0) {
268			name = "cpu-current";
269			shift = 8;
270			isens[core] = index;
271		} else if (strcmp(type, "temp-sensor") == 0) {
272			name = "cpu-temp";
273			shift = 10;
274		} else
275			continue;	/* hmmm shouldn't happen */
276
277		/* the +16 is enough for "cpu-voltage-n" */
278		sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
279		if (sens == NULL) {
280			printk(KERN_ERR "wf_sat_create: couldn't create "
281			       "%s sensor %d (no memory)\n", name, cpu);
282			continue;
283		}
284		sens->index = index;
285		sens->index2 = -1;
286		sens->shift = shift;
287		sens->sat = sat;
288		sens->sens.ops = &wf_sat_ops;
289		sens->sens.name = (char *) (sens + 1);
290		snprintf((char *)sens->sens.name, 16, "%s-%d", name, cpu);
291
292		if (wf_register_sensor(&sens->sens))
293			kfree(sens);
294		else {
295			list_add(&sens->link, &sat->sensors);
296			kref_get(&sat->ref);
297		}
298	}
299
300	/* make the power sensors */
301	for (core = 0; core < 2; ++core) {
302		if (vsens[core] < 0 || isens[core] < 0)
303			continue;
304		cpu = 2 * sat->nr + core;
305		sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
306		if (sens == NULL) {
307			printk(KERN_ERR "wf_sat_create: couldn't create power "
308			       "sensor %d (no memory)\n", cpu);
309			continue;
310		}
311		sens->index = vsens[core];
312		sens->index2 = isens[core];
313		sens->shift = 0;
314		sens->sat = sat;
315		sens->sens.ops = &wf_sat_ops;
316		sens->sens.name = (char *) (sens + 1);
317		snprintf((char *)sens->sens.name, 16, "cpu-power-%d", cpu);
318
319		if (wf_register_sensor(&sens->sens))
320			kfree(sens);
321		else {
322			list_add(&sens->link, &sat->sensors);
323			kref_get(&sat->ref);
324		}
325	}
326
327	if (sat->nr >= 0)
328		sats[sat->nr] = sat;
329
330	return 0;
331}
332
333static int wf_sat_remove(struct i2c_client *client)
334{
335	struct wf_sat *sat = i2c_get_clientdata(client);
336	struct wf_sat_sensor *sens;
337
338	/* release sensors */
339	while(!list_empty(&sat->sensors)) {
340		sens = list_first_entry(&sat->sensors,
341					struct wf_sat_sensor, link);
342		list_del(&sens->link);
343		wf_unregister_sensor(&sens->sens);
344	}
345	sat->i2c = NULL;
346	kref_put(&sat->ref, wf_sat_release);
347
348	return 0;
349}
350
351static const struct i2c_device_id wf_sat_id[] = {
352	{ "MAC,smu-sat", 0 },
353	{ }
354};
355MODULE_DEVICE_TABLE(i2c, wf_sat_id);
356
357static struct i2c_driver wf_sat_driver = {
358	.driver = {
359		.name		= "wf_smu_sat",
360	},
361	.probe		= wf_sat_probe,
362	.remove		= wf_sat_remove,
363	.id_table	= wf_sat_id,
364};
365
366module_i2c_driver(wf_sat_driver);
367
368MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
369MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
370MODULE_LICENSE("GPL");
371