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 <asm/semaphore.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 semaphore 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 #define i2c_to_sat(c) container_of(c, struct wf_sat, i2c)
58
59 static int wf_sat_attach(struct i2c_adapter *adapter);
60 static int wf_sat_detach(struct i2c_client *client);
61
62 static struct i2c_driver wf_sat_driver = {
63 .driver = {
64 .name = "wf_smu_sat",
65 },
66 .attach_adapter = wf_sat_attach,
67 .detach_client = wf_sat_detach,
68 };
69
70 /*
71 * XXX i2c_smbus_read_i2c_block_data doesn't pass the requested
72 * length down to the low-level driver, so we use this, which
73 * works well enough with the SMU i2c driver code...
74 */
75 static int sat_read_block(struct i2c_client *client, u8 command,
76 u8 *values, int len)
77 {
78 union i2c_smbus_data data;
79 int err;
80
81 data.block[0] = len;
82 err = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
83 I2C_SMBUS_READ, command, I2C_SMBUS_I2C_BLOCK_DATA,
84 &data);
85 if (!err)
86 memcpy(values, data.block, len);
87 return err;
88 }
89
90 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
91 unsigned int *size)
92 {
93 struct wf_sat *sat;
94 int err;
95 unsigned int i, len;
96 u8 *buf;
97 u8 data[4];
98
99 /* TODO: Add the resulting partition to the device-tree */
100
101 if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
102 return NULL;
103
104 err = i2c_smbus_write_word_data(&sat->i2c, 8, id << 8);
105 if (err) {
106 printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
107 return NULL;
108 }
109
110 len = i2c_smbus_read_word_data(&sat->i2c, 9);
111 if (len < 0) {
112 printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
113 return NULL;
114 }
115 if (len == 0) {
116 printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
117 return NULL;
118 }
119
120 len = le16_to_cpu(len);
121 len = (len + 3) & ~3;
122 buf = kmalloc(len, GFP_KERNEL);
123 if (buf == NULL)
124 return NULL;
125
126 for (i = 0; i < len; i += 4) {
127 err = sat_read_block(&sat->i2c, 0xa, data, 4);
128 if (err) {
129 printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
130 err);
131 goto fail;
132 }
133 buf[i] = data[1];
134 buf[i+1] = data[0];
135 buf[i+2] = data[3];
136 buf[i+3] = data[2];
137 }
138 #ifdef DEBUG
139 DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
140 for (i = 0; i < len; ++i)
141 DBG(" %x", buf[i]);
142 DBG("\n");
143 #endif
144
145 if (size)
146 *size = len;
147 return (struct smu_sdbp_header *) buf;
148
149 fail:
150 kfree(buf);
151 return NULL;
152 }
153 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
154
155 /* refresh the cache */
156 static int wf_sat_read_cache(struct wf_sat *sat)
157 {
158 int err;
159
160 err = sat_read_block(&sat->i2c, 0x3f, sat->cache, 16);
161 if (err)
162 return err;
163 sat->last_read = jiffies;
164 #ifdef LOTSA_DEBUG
165 {
166 int i;
167 DBG(KERN_DEBUG "wf_sat_get: data is");
168 for (i = 0; i < 16; ++i)
169 DBG(" %.2x", sat->cache[i]);
170 DBG("\n");
171 }
172 #endif
173 return 0;
174 }
175
176 static int wf_sat_get(struct wf_sensor *sr, s32 *value)
177 {
178 struct wf_sat_sensor *sens = wf_to_sat(sr);
179 struct wf_sat *sat = sens->sat;
180 int i, err;
181 s32 val;
182
183 if (sat->i2c.adapter == NULL)
184 return -ENODEV;
185
186 down(&sat->mutex);
187 if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
188 err = wf_sat_read_cache(sat);
189 if (err)
190 goto fail;
191 }
192
193 i = sens->index * 2;
194 val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
195 if (sens->index2 >= 0) {
196 i = sens->index2 * 2;
197 /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
198 val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
199 }
200
201 *value = val;
202 err = 0;
203
204 fail:
205 up(&sat->mutex);
206 return err;
207 }
208
209 static void wf_sat_release(struct wf_sensor *sr)
210 {
211 struct wf_sat_sensor *sens = wf_to_sat(sr);
212 struct wf_sat *sat = sens->sat;
213
214 if (atomic_dec_and_test(&sat->refcnt)) {
215 if (sat->i2c.adapter) {
216 i2c_detach_client(&sat->i2c);
217 sat->i2c.adapter = NULL;
218 }
219 if (sat->nr >= 0)
220 sats[sat->nr] = NULL;
221 kfree(sat);
222 }
223 kfree(sens);
224 }
225
226 static struct wf_sensor_ops wf_sat_ops = {
227 .get_value = wf_sat_get,
228 .release = wf_sat_release,
229 .owner = THIS_MODULE,
230 };
231
232 static void wf_sat_create(struct i2c_adapter *adapter, struct device_node *dev)
233 {
234 struct wf_sat *sat;
235 struct wf_sat_sensor *sens;
236 u32 *reg;
237 char *loc, *type;
238 u8 addr, chip, core;
239 struct device_node *child;
240 int shift, cpu, index;
241 char *name;
242 int vsens[2], isens[2];
243
244 reg = (u32 *) get_property(dev, "reg", NULL);
245 if (reg == NULL)
246 return;
247 addr = *reg;
248 DBG(KERN_DEBUG "wf_sat: creating sat at address %x\n", addr);
249
250 sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
251 if (sat == NULL)
252 return;
253 sat->nr = -1;
254 sat->node = of_node_get(dev);
255 atomic_set(&sat->refcnt, 0);
256 init_MUTEX(&sat->mutex);
257 sat->i2c.addr = (addr >> 1) & 0x7f;
258 sat->i2c.adapter = adapter;
259 sat->i2c.driver = &wf_sat_driver;
260 strncpy(sat->i2c.name, "smu-sat", I2C_NAME_SIZE-1);
261
262 if (i2c_attach_client(&sat->i2c)) {
263 printk(KERN_ERR "windfarm: failed to attach smu-sat to i2c\n");
264 goto fail;
265 }
266
267 vsens[0] = vsens[1] = -1;
268 isens[0] = isens[1] = -1;
269 child = NULL;
270 while ((child = of_get_next_child(dev, child)) != NULL) {
271 reg = (u32 *) get_property(child, "reg", NULL);
272 type = get_property(child, "device_type", NULL);
273 loc = get_property(child, "location", NULL);
274 if (reg == NULL || loc == NULL)
275 continue;
276
277 /* the cooked sensors are between 0x30 and 0x37 */
278 if (*reg < 0x30 || *reg > 0x37)
279 continue;
280 index = *reg - 0x30;
281
282 /* expect location to be CPU [AB][01] ... */
283 if (strncmp(loc, "CPU ", 4) != 0)
284 continue;
285 chip = loc[4] - 'A';
286 core = loc[5] - '';
287 if (chip > 1 || core > 1) {
288 printk(KERN_ERR "wf_sat_create: don't understand "
289 "location %s for %s\n", loc, child->full_name);
290 continue;
291 }
292 cpu = 2 * chip + core;
293 if (sat->nr < 0)
294 sat->nr = chip;
295 else if (sat->nr != chip) {
296 printk(KERN_ERR "wf_sat_create: can't cope with "
297 "multiple CPU chips on one SAT (%s)\n", loc);
298 continue;
299 }
300
301 if (strcmp(type, "voltage-sensor") == 0) {
302 name = "cpu-voltage";
303 shift = 4;
304 vsens[core] = index;
305 } else if (strcmp(type, "current-sensor") == 0) {
306 name = "cpu-current";
307 shift = 8;
308 isens[core] = index;
309 } else if (strcmp(type, "temp-sensor") == 0) {
310 name = "cpu-temp";
311 shift = 10;
312 } else
313 continue; /* hmmm shouldn't happen */
314
315 /* the +16 is enough for "cpu-voltage-n" */
316 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
317 if (sens == NULL) {
318 printk(KERN_ERR "wf_sat_create: couldn't create "
319 "%s sensor %d (no memory)\n", name, cpu);
320 continue;
321 }
322 sens->index = index;
323 sens->index2 = -1;
324 sens->shift = shift;
325 sens->sat = sat;
326 atomic_inc(&sat->refcnt);
327 sens->sens.ops = &wf_sat_ops;
328 sens->sens.name = (char *) (sens + 1);
329 snprintf(sens->sens.name, 16, "%s-%d", name, cpu);
330
331 if (wf_register_sensor(&sens->sens)) {
332 atomic_dec(&sat->refcnt);
333 kfree(sens);
334 }
335 }
336
337 /* make the power sensors */
338 for (core = 0; core < 2; ++core) {
339 if (vsens[core] < 0 || isens[core] < 0)
340 continue;
341 cpu = 2 * sat->nr + core;
342 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
343 if (sens == NULL) {
344 printk(KERN_ERR "wf_sat_create: couldn't create power "
345 "sensor %d (no memory)\n", cpu);
346 continue;
347 }
348 sens->index = vsens[core];
349 sens->index2 = isens[core];
350 sens->shift = 0;
351 sens->sat = sat;
352 atomic_inc(&sat->refcnt);
353 sens->sens.ops = &wf_sat_ops;
354 sens->sens.name = (char *) (sens + 1);
355 snprintf(sens->sens.name, 16, "cpu-power-%d", cpu);
356
357 if (wf_register_sensor(&sens->sens)) {
358 atomic_dec(&sat->refcnt);
359 kfree(sens);
360 }
361 }
362
363 if (sat->nr >= 0)
364 sats[sat->nr] = sat;
365
366 return;
367
368 fail:
369 kfree(sat);
370 }
371
372 static int wf_sat_attach(struct i2c_adapter *adapter)
373 {
374 struct device_node *busnode, *dev = NULL;
375 struct pmac_i2c_bus *bus;
376
377 bus = pmac_i2c_adapter_to_bus(adapter);
378 if (bus == NULL)
379 return -ENODEV;
380 busnode = pmac_i2c_get_bus_node(bus);
381
382 while ((dev = of_get_next_child(busnode, dev)) != NULL)
383 if (device_is_compatible(dev, "smu-sat"))
384 wf_sat_create(adapter, dev);
385 return 0;
386 }
387
388 static int wf_sat_detach(struct i2c_client *client)
389 {
390 struct wf_sat *sat = i2c_to_sat(client);
391
392 /* XXX TODO */
393
394 sat->i2c.adapter = NULL;
395 return 0;
396 }
397
398 static int __init sat_sensors_init(void)
399 {
400 int err;
401
402 err = i2c_add_driver(&wf_sat_driver);
403 if (err < 0)
404 return err;
405 return 0;
406 }
407
408 static void __exit sat_sensors_exit(void)
409 {
410 i2c_del_driver(&wf_sat_driver);
411 }
412
413 module_init(sat_sensors_init);
414 /*module_exit(sat_sensors_exit); Uncomment when cleanup is implemented */
415
416 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
417 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
418 MODULE_LICENSE("GPL");
419
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