xref: /openbmc/linux/drivers/macintosh/windfarm_smu_sat.c (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1)
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 /* If the cache is older than 800ms we'll refetch it */
26 #define MAX_AGE		msecs_to_jiffies(800)
27 
28 struct wf_sat {
29 	struct kref		ref;
30 	int			nr;
31 	struct mutex		mutex;
32 	unsigned long		last_read; /* jiffies when cache last updated */
33 	u8			cache[16];
34 	struct list_head	sensors;
35 	struct i2c_client	*i2c;
36 	struct device_node	*node;
37 };
38 
39 static struct wf_sat *sats[2];
40 
41 struct wf_sat_sensor {
42 	struct list_head	link;
43 	int			index;
44 	int			index2;		/* used for power sensors */
45 	int			shift;
46 	struct wf_sat		*sat;
47 	struct wf_sensor 	sens;
48 };
49 
50 #define wf_to_sat(c)	container_of(c, struct wf_sat_sensor, sens)
51 
52 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
53 						  unsigned int *size)
54 {
55 	struct wf_sat *sat;
56 	int err;
57 	unsigned int i, len;
58 	u8 *buf;
59 	u8 data[4];
60 
61 	/* TODO: Add the resulting partition to the device-tree */
62 
63 	if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
64 		return NULL;
65 
66 	err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
67 	if (err) {
68 		printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
69 		return NULL;
70 	}
71 
72 	err = i2c_smbus_read_word_data(sat->i2c, 9);
73 	if (err < 0) {
74 		printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
75 		return NULL;
76 	}
77 	len = err;
78 	if (len == 0) {
79 		printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
80 		return NULL;
81 	}
82 
83 	len = le16_to_cpu(len);
84 	len = (len + 3) & ~3;
85 	buf = kmalloc(len, GFP_KERNEL);
86 	if (buf == NULL)
87 		return NULL;
88 
89 	for (i = 0; i < len; i += 4) {
90 		err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
91 		if (err < 0) {
92 			printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
93 			       err);
94 			goto fail;
95 		}
96 		buf[i] = data[1];
97 		buf[i+1] = data[0];
98 		buf[i+2] = data[3];
99 		buf[i+3] = data[2];
100 	}
101 
102 	printk(KERN_DEBUG "sat %d partition %x:", sat_id, id);
103 	print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
104 		       16, 1, buf, len, false);
105 	if (size)
106 		*size = len;
107 	return (struct smu_sdbp_header *) buf;
108 
109  fail:
110 	kfree(buf);
111 	return NULL;
112 }
113 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
114 
115 /* refresh the cache */
116 static int wf_sat_read_cache(struct wf_sat *sat)
117 {
118 	int err;
119 
120 	err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
121 	if (err < 0)
122 		return err;
123 	sat->last_read = jiffies;
124 
125 #ifdef LOTSA_DEBUG
126 	{
127 		int i;
128 		printk(KERN_DEBUG "wf_sat_get: data is");
129 		print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
130 			       16, 1, sat->cache, 16, false);
131 	}
132 #endif
133 	return 0;
134 }
135 
136 static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
137 {
138 	struct wf_sat_sensor *sens = wf_to_sat(sr);
139 	struct wf_sat *sat = sens->sat;
140 	int i, err;
141 	s32 val;
142 
143 	if (sat->i2c == NULL)
144 		return -ENODEV;
145 
146 	mutex_lock(&sat->mutex);
147 	if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
148 		err = wf_sat_read_cache(sat);
149 		if (err)
150 			goto fail;
151 	}
152 
153 	i = sens->index * 2;
154 	val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
155 	if (sens->index2 >= 0) {
156 		i = sens->index2 * 2;
157 		/* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
158 		val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
159 	}
160 
161 	*value = val;
162 	err = 0;
163 
164  fail:
165 	mutex_unlock(&sat->mutex);
166 	return err;
167 }
168 
169 static void wf_sat_release(struct kref *ref)
170 {
171 	struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
172 
173 	if (sat->nr >= 0)
174 		sats[sat->nr] = NULL;
175 	kfree(sat);
176 }
177 
178 static void wf_sat_sensor_release(struct wf_sensor *sr)
179 {
180 	struct wf_sat_sensor *sens = wf_to_sat(sr);
181 	struct wf_sat *sat = sens->sat;
182 
183 	kfree(sens);
184 	kref_put(&sat->ref, wf_sat_release);
185 }
186 
187 static const struct wf_sensor_ops wf_sat_ops = {
188 	.get_value	= wf_sat_sensor_get,
189 	.release	= wf_sat_sensor_release,
190 	.owner		= THIS_MODULE,
191 };
192 
193 static int wf_sat_probe(struct i2c_client *client,
194 			const struct i2c_device_id *id)
195 {
196 	struct device_node *dev = client->dev.of_node;
197 	struct wf_sat *sat;
198 	struct wf_sat_sensor *sens;
199 	const u32 *reg;
200 	const char *loc, *type;
201 	u8 chip, core;
202 	struct device_node *child;
203 	int shift, cpu, index;
204 	char *name;
205 	int vsens[2], isens[2];
206 
207 	sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
208 	if (sat == NULL)
209 		return -ENOMEM;
210 	sat->nr = -1;
211 	sat->node = of_node_get(dev);
212 	kref_init(&sat->ref);
213 	mutex_init(&sat->mutex);
214 	sat->i2c = client;
215 	INIT_LIST_HEAD(&sat->sensors);
216 	i2c_set_clientdata(client, sat);
217 
218 	vsens[0] = vsens[1] = -1;
219 	isens[0] = isens[1] = -1;
220 	child = NULL;
221 	while ((child = of_get_next_child(dev, child)) != NULL) {
222 		reg = of_get_property(child, "reg", NULL);
223 		type = of_get_property(child, "device_type", NULL);
224 		loc = of_get_property(child, "location", NULL);
225 		if (reg == NULL || loc == NULL)
226 			continue;
227 
228 		/* the cooked sensors are between 0x30 and 0x37 */
229 		if (*reg < 0x30 || *reg > 0x37)
230 			continue;
231 		index = *reg - 0x30;
232 
233 		/* expect location to be CPU [AB][01] ... */
234 		if (strncmp(loc, "CPU ", 4) != 0)
235 			continue;
236 		chip = loc[4] - 'A';
237 		core = loc[5] - '0';
238 		if (chip > 1 || core > 1) {
239 			printk(KERN_ERR "wf_sat_create: don't understand "
240 			       "location %s for %pOF\n", loc, child);
241 			continue;
242 		}
243 		cpu = 2 * chip + core;
244 		if (sat->nr < 0)
245 			sat->nr = chip;
246 		else if (sat->nr != chip) {
247 			printk(KERN_ERR "wf_sat_create: can't cope with "
248 			       "multiple CPU chips on one SAT (%s)\n", loc);
249 			continue;
250 		}
251 
252 		if (strcmp(type, "voltage-sensor") == 0) {
253 			name = "cpu-voltage";
254 			shift = 4;
255 			vsens[core] = index;
256 		} else if (strcmp(type, "current-sensor") == 0) {
257 			name = "cpu-current";
258 			shift = 8;
259 			isens[core] = index;
260 		} else if (strcmp(type, "temp-sensor") == 0) {
261 			name = "cpu-temp";
262 			shift = 10;
263 		} else
264 			continue;	/* hmmm shouldn't happen */
265 
266 		/* the +16 is enough for "cpu-voltage-n" */
267 		sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
268 		if (sens == NULL) {
269 			printk(KERN_ERR "wf_sat_create: couldn't create "
270 			       "%s sensor %d (no memory)\n", name, cpu);
271 			continue;
272 		}
273 		sens->index = index;
274 		sens->index2 = -1;
275 		sens->shift = shift;
276 		sens->sat = sat;
277 		sens->sens.ops = &wf_sat_ops;
278 		sens->sens.name = (char *) (sens + 1);
279 		snprintf((char *)sens->sens.name, 16, "%s-%d", name, cpu);
280 
281 		if (wf_register_sensor(&sens->sens))
282 			kfree(sens);
283 		else {
284 			list_add(&sens->link, &sat->sensors);
285 			kref_get(&sat->ref);
286 		}
287 	}
288 
289 	/* make the power sensors */
290 	for (core = 0; core < 2; ++core) {
291 		if (vsens[core] < 0 || isens[core] < 0)
292 			continue;
293 		cpu = 2 * sat->nr + core;
294 		sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
295 		if (sens == NULL) {
296 			printk(KERN_ERR "wf_sat_create: couldn't create power "
297 			       "sensor %d (no memory)\n", cpu);
298 			continue;
299 		}
300 		sens->index = vsens[core];
301 		sens->index2 = isens[core];
302 		sens->shift = 0;
303 		sens->sat = sat;
304 		sens->sens.ops = &wf_sat_ops;
305 		sens->sens.name = (char *) (sens + 1);
306 		snprintf((char *)sens->sens.name, 16, "cpu-power-%d", cpu);
307 
308 		if (wf_register_sensor(&sens->sens))
309 			kfree(sens);
310 		else {
311 			list_add(&sens->link, &sat->sensors);
312 			kref_get(&sat->ref);
313 		}
314 	}
315 
316 	if (sat->nr >= 0)
317 		sats[sat->nr] = sat;
318 
319 	return 0;
320 }
321 
322 static int wf_sat_remove(struct i2c_client *client)
323 {
324 	struct wf_sat *sat = i2c_get_clientdata(client);
325 	struct wf_sat_sensor *sens;
326 
327 	/* release sensors */
328 	while(!list_empty(&sat->sensors)) {
329 		sens = list_first_entry(&sat->sensors,
330 					struct wf_sat_sensor, link);
331 		list_del(&sens->link);
332 		wf_unregister_sensor(&sens->sens);
333 	}
334 	sat->i2c = NULL;
335 	kref_put(&sat->ref, wf_sat_release);
336 
337 	return 0;
338 }
339 
340 static const struct i2c_device_id wf_sat_id[] = {
341 	{ "MAC,smu-sat", 0 },
342 	{ }
343 };
344 MODULE_DEVICE_TABLE(i2c, wf_sat_id);
345 
346 static struct i2c_driver wf_sat_driver = {
347 	.driver = {
348 		.name		= "wf_smu_sat",
349 	},
350 	.probe		= wf_sat_probe,
351 	.remove		= wf_sat_remove,
352 	.id_table	= wf_sat_id,
353 };
354 
355 module_i2c_driver(wf_sat_driver);
356 
357 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
358 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
359 MODULE_LICENSE("GPL");
360