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 "0.2"
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
36 struct wf_sat {
37 int nr;
38 atomic_t refcnt;
39 struct mutex mutex;
40 unsigned long last_read; /* jiffies when cache last updated */
41 u8 cache[16];
42 struct i2c_client *i2c;
43 struct device_node *node;
44 };
45
46 static struct wf_sat *sats[2];
47
48 struct wf_sat_sensor {
49 int index;
50 int index2; /* used for power sensors */
51 int shift;
52 struct wf_sat *sat;
53 struct wf_sensor sens;
54 };
55
56 #define wf_to_sat(c) container_of(c, struct wf_sat_sensor, sens)
57
smu_sat_get_sdb_partition(unsigned int sat_id,int id,unsigned int * size)58 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
59 unsigned int *size)
60 {
61 struct wf_sat *sat;
62 int err;
63 unsigned int i, len;
64 u8 *buf;
65 u8 data[4];
66
67 /* TODO: Add the resulting partition to the device-tree */
68
69 if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
70 return NULL;
71
72 err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
73 if (err) {
74 printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
75 return NULL;
76 }
77
78 err = i2c_smbus_read_word_data(sat->i2c, 9);
79 if (err < 0) {
80 printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
81 return NULL;
82 }
83 len = err;
84 if (len == 0) {
85 printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
86 return NULL;
87 }
88
89 len = le16_to_cpu(len);
90 len = (len + 3) & ~3;
91 buf = kmalloc(len, GFP_KERNEL);
92 if (buf == NULL)
93 return NULL;
94
95 for (i = 0; i < len; i += 4) {
96 err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
97 if (err < 0) {
98 printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
99 err);
100 goto fail;
101 }
102 buf[i] = data[1];
103 buf[i+1] = data[0];
104 buf[i+2] = data[3];
105 buf[i+3] = data[2];
106 }
107 #ifdef DEBUG
108 DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
109 for (i = 0; i < len; ++i)
110 DBG(" %x", buf[i]);
111 DBG("\n");
112 #endif
113
114 if (size)
115 *size = len;
116 return (struct smu_sdbp_header *) buf;
117
118 fail:
119 kfree(buf);
120 return NULL;
121 }
122 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
123
124 /* refresh the cache */
wf_sat_read_cache(struct wf_sat * sat)125 static int wf_sat_read_cache(struct wf_sat *sat)
126 {
127 int err;
128
129 err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
130 if (err < 0)
131 return err;
132 sat->last_read = jiffies;
133 #ifdef LOTSA_DEBUG
134 {
135 int i;
136 DBG(KERN_DEBUG "wf_sat_get: data is");
137 for (i = 0; i < 16; ++i)
138 DBG(" %.2x", sat->cache[i]);
139 DBG("\n");
140 }
141 #endif
142 return 0;
143 }
144
wf_sat_get(struct wf_sensor * sr,s32 * value)145 static int wf_sat_get(struct wf_sensor *sr, s32 *value)
146 {
147 struct wf_sat_sensor *sens = wf_to_sat(sr);
148 struct wf_sat *sat = sens->sat;
149 int i, err;
150 s32 val;
151
152 if (sat->i2c == NULL)
153 return -ENODEV;
154
155 mutex_lock(&sat->mutex);
156 if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
157 err = wf_sat_read_cache(sat);
158 if (err)
159 goto fail;
160 }
161
162 i = sens->index * 2;
163 val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
164 if (sens->index2 >= 0) {
165 i = sens->index2 * 2;
166 /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
167 val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
168 }
169
170 *value = val;
171 err = 0;
172
173 fail:
174 mutex_unlock(&sat->mutex);
175 return err;
176 }
177
wf_sat_release(struct wf_sensor * sr)178 static void wf_sat_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 if (atomic_dec_and_test(&sat->refcnt)) {
184 if (sat->nr >= 0)
185 sats[sat->nr] = NULL;
186 kfree(sat);
187 }
188 kfree(sens);
189 }
190
191 static struct wf_sensor_ops wf_sat_ops = {
192 .get_value = wf_sat_get,
193 .release = wf_sat_release,
194 .owner = THIS_MODULE,
195 };
196
197 static struct i2c_driver wf_sat_driver;
198
wf_sat_create(struct i2c_adapter * adapter,struct device_node * dev)199 static void wf_sat_create(struct i2c_adapter *adapter, struct device_node *dev)
200 {
201 struct i2c_board_info info;
202 struct i2c_client *client;
203 const u32 *reg;
204 u8 addr;
205
206 reg = of_get_property(dev, "reg", NULL);
207 if (reg == NULL)
208 return;
209 addr = *reg;
210 DBG(KERN_DEBUG "wf_sat: creating sat at address %x\n", addr);
211
212 memset(&info, 0, sizeof(struct i2c_board_info));
213 info.addr = (addr >> 1) & 0x7f;
214 info.platform_data = dev;
215 strlcpy(info.type, "wf_sat", I2C_NAME_SIZE);
216
217 client = i2c_new_device(adapter, &info);
218 if (client == NULL) {
219 printk(KERN_ERR "windfarm: failed to attach smu-sat to i2c\n");
220 return;
221 }
222
223 /*
224 * Let i2c-core delete that device on driver removal.
225 * This is safe because i2c-core holds the core_lock mutex for us.
226 */
227 list_add_tail(&client->detected, &wf_sat_driver.clients);
228 }
229
wf_sat_probe(struct i2c_client * client,const struct i2c_device_id * id)230 static int wf_sat_probe(struct i2c_client *client,
231 const struct i2c_device_id *id)
232 {
233 struct device_node *dev = client->dev.platform_data;
234 struct wf_sat *sat;
235 struct wf_sat_sensor *sens;
236 const u32 *reg;
237 const char *loc, *type;
238 u8 chip, core;
239 struct device_node *child;
240 int shift, cpu, index;
241 char *name;
242 int vsens[2], isens[2];
243
244 sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
245 if (sat == NULL)
246 return -ENOMEM;
247 sat->nr = -1;
248 sat->node = of_node_get(dev);
249 atomic_set(&sat->refcnt, 0);
250 mutex_init(&sat->mutex);
251 sat->i2c = client;
252 i2c_set_clientdata(client, sat);
253
254 vsens[0] = vsens[1] = -1;
255 isens[0] = isens[1] = -1;
256 child = NULL;
257 while ((child = of_get_next_child(dev, child)) != NULL) {
258 reg = of_get_property(child, "reg", NULL);
259 type = of_get_property(child, "device_type", NULL);
260 loc = of_get_property(child, "location", NULL);
261 if (reg == NULL || loc == NULL)
262 continue;
263
264 /* the cooked sensors are between 0x30 and 0x37 */
265 if (*reg < 0x30 || *reg > 0x37)
266 continue;
267 index = *reg - 0x30;
268
269 /* expect location to be CPU [AB][01] ... */
270 if (strncmp(loc, "CPU ", 4) != 0)
271 continue;
272 chip = loc[4] - 'A';
273 core = loc[5] - '0';
274 if (chip > 1 || core > 1) {
275 printk(KERN_ERR "wf_sat_create: don't understand "
276 "location %s for %s\n", loc, child->full_name);
277 continue;
278 }
279 cpu = 2 * chip + core;
280 if (sat->nr < 0)
281 sat->nr = chip;
282 else if (sat->nr != chip) {
283 printk(KERN_ERR "wf_sat_create: can't cope with "
284 "multiple CPU chips on one SAT (%s)\n", loc);
285 continue;
286 }
287
288 if (strcmp(type, "voltage-sensor") == 0) {
289 name = "cpu-voltage";
290 shift = 4;
291 vsens[core] = index;
292 } else if (strcmp(type, "current-sensor") == 0) {
293 name = "cpu-current";
294 shift = 8;
295 isens[core] = index;
296 } else if (strcmp(type, "temp-sensor") == 0) {
297 name = "cpu-temp";
298 shift = 10;
299 } else
300 continue; /* hmmm shouldn't happen */
301
302 /* the +16 is enough for "cpu-voltage-n" */
303 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
304 if (sens == NULL) {
305 printk(KERN_ERR "wf_sat_create: couldn't create "
306 "%s sensor %d (no memory)\n", name, cpu);
307 continue;
308 }
309 sens->index = index;
310 sens->index2 = -1;
311 sens->shift = shift;
312 sens->sat = sat;
313 atomic_inc(&sat->refcnt);
314 sens->sens.ops = &wf_sat_ops;
315 sens->sens.name = (char *) (sens + 1);
316 snprintf(sens->sens.name, 16, "%s-%d", name, cpu);
317
318 if (wf_register_sensor(&sens->sens)) {
319 atomic_dec(&sat->refcnt);
320 kfree(sens);
321 }
322 }
323
324 /* make the power sensors */
325 for (core = 0; core < 2; ++core) {
326 if (vsens[core] < 0 || isens[core] < 0)
327 continue;
328 cpu = 2 * sat->nr + core;
329 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
330 if (sens == NULL) {
331 printk(KERN_ERR "wf_sat_create: couldn't create power "
332 "sensor %d (no memory)\n", cpu);
333 continue;
334 }
335 sens->index = vsens[core];
336 sens->index2 = isens[core];
337 sens->shift = 0;
338 sens->sat = sat;
339 atomic_inc(&sat->refcnt);
340 sens->sens.ops = &wf_sat_ops;
341 sens->sens.name = (char *) (sens + 1);
342 snprintf(sens->sens.name, 16, "cpu-power-%d", cpu);
343
344 if (wf_register_sensor(&sens->sens)) {
345 atomic_dec(&sat->refcnt);
346 kfree(sens);
347 }
348 }
349
350 if (sat->nr >= 0)
351 sats[sat->nr] = sat;
352
353 return 0;
354 }
355
wf_sat_attach(struct i2c_adapter * adapter)356 static int wf_sat_attach(struct i2c_adapter *adapter)
357 {
358 struct device_node *busnode, *dev = NULL;
359 struct pmac_i2c_bus *bus;
360
361 bus = pmac_i2c_adapter_to_bus(adapter);
362 if (bus == NULL)
363 return -ENODEV;
364 busnode = pmac_i2c_get_bus_node(bus);
365
366 while ((dev = of_get_next_child(busnode, dev)) != NULL)
367 if (of_device_is_compatible(dev, "smu-sat"))
368 wf_sat_create(adapter, dev);
369 return 0;
370 }
371
wf_sat_remove(struct i2c_client * client)372 static int wf_sat_remove(struct i2c_client *client)
373 {
374 struct wf_sat *sat = i2c_get_clientdata(client);
375
376 /* XXX TODO */
377
378 sat->i2c = NULL;
379 return 0;
380 }
381
382 static const struct i2c_device_id wf_sat_id[] = {
383 { "wf_sat", 0 },
384 { }
385 };
386
387 static struct i2c_driver wf_sat_driver = {
388 .driver = {
389 .name = "wf_smu_sat",
390 },
391 .attach_adapter = wf_sat_attach,
392 .probe = wf_sat_probe,
393 .remove = wf_sat_remove,
394 .id_table = wf_sat_id,
395 };
396
sat_sensors_init(void)397 static int __init sat_sensors_init(void)
398 {
399 return i2c_add_driver(&wf_sat_driver);
400 }
401
402 #if 0 /* uncomment when module_exit() below is uncommented */
403 static void __exit sat_sensors_exit(void)
404 {
405 i2c_del_driver(&wf_sat_driver);
406 }
407 #endif
408
409 module_init(sat_sensors_init);
410 /*module_exit(sat_sensors_exit); Uncomment when cleanup is implemented */
411
412 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
413 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
414 MODULE_LICENSE("GPL");
415