1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Windfarm PowerMac thermal control. SMU "satellite" controller sensors.
4 *
5 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
6 */
7
8 #include <linux/types.h>
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/wait.h>
14 #include <linux/i2c.h>
15 #include <linux/mutex.h>
16
17 #include <asm/smu.h>
18 #include <asm/pmac_low_i2c.h>
19
20 #include "windfarm.h"
21
22 #define VERSION "1.0"
23
24 /* If the cache is older than 800ms we'll refetch it */
25 #define MAX_AGE msecs_to_jiffies(800)
26
27 struct wf_sat {
28 struct kref ref;
29 int nr;
30 struct mutex mutex;
31 unsigned long last_read; /* jiffies when cache last updated */
32 u8 cache[16];
33 struct list_head sensors;
34 struct i2c_client *i2c;
35 struct device_node *node;
36 };
37
38 static struct wf_sat *sats[2];
39
40 struct wf_sat_sensor {
41 struct list_head link;
42 int index;
43 int index2; /* used for power sensors */
44 int shift;
45 struct wf_sat *sat;
46 struct wf_sensor sens;
47 };
48
49 #define wf_to_sat(c) container_of(c, struct wf_sat_sensor, sens)
50
smu_sat_get_sdb_partition(unsigned int sat_id,int id,unsigned int * size)51 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
52 unsigned int *size)
53 {
54 struct wf_sat *sat;
55 int err;
56 unsigned int i, len;
57 u8 *buf;
58 u8 data[4];
59
60 /* TODO: Add the resulting partition to the device-tree */
61
62 if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
63 return NULL;
64
65 err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
66 if (err) {
67 printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
68 return NULL;
69 }
70
71 err = i2c_smbus_read_word_data(sat->i2c, 9);
72 if (err < 0) {
73 printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
74 return NULL;
75 }
76 len = err;
77 if (len == 0) {
78 printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
79 return NULL;
80 }
81
82 len = le16_to_cpu(len);
83 len = (len + 3) & ~3;
84 buf = kmalloc(len, GFP_KERNEL);
85 if (buf == NULL)
86 return NULL;
87
88 for (i = 0; i < len; i += 4) {
89 err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
90 if (err < 0) {
91 printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
92 err);
93 goto fail;
94 }
95 buf[i] = data[1];
96 buf[i+1] = data[0];
97 buf[i+2] = data[3];
98 buf[i+3] = data[2];
99 }
100
101 printk(KERN_DEBUG "sat %d partition %x:", sat_id, id);
102 print_hex_dump(KERN_DEBUG, " ", DUMP_PREFIX_OFFSET,
103 16, 1, buf, len, false);
104 if (size)
105 *size = len;
106 return (struct smu_sdbp_header *) buf;
107
108 fail:
109 kfree(buf);
110 return NULL;
111 }
112 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
113
114 /* refresh the cache */
wf_sat_read_cache(struct wf_sat * sat)115 static int wf_sat_read_cache(struct wf_sat *sat)
116 {
117 int err;
118
119 err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
120 if (err < 0)
121 return err;
122 sat->last_read = jiffies;
123
124 #ifdef LOTSA_DEBUG
125 {
126 int i;
127 printk(KERN_DEBUG "wf_sat_get: data is");
128 print_hex_dump(KERN_DEBUG, " ", DUMP_PREFIX_OFFSET,
129 16, 1, sat->cache, 16, false);
130 }
131 #endif
132 return 0;
133 }
134
wf_sat_sensor_get(struct wf_sensor * sr,s32 * value)135 static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
136 {
137 struct wf_sat_sensor *sens = wf_to_sat(sr);
138 struct wf_sat *sat = sens->sat;
139 int i, err;
140 s32 val;
141
142 if (sat->i2c == NULL)
143 return -ENODEV;
144
145 mutex_lock(&sat->mutex);
146 if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
147 err = wf_sat_read_cache(sat);
148 if (err)
149 goto fail;
150 }
151
152 i = sens->index * 2;
153 val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
154 if (sens->index2 >= 0) {
155 i = sens->index2 * 2;
156 /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
157 val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
158 }
159
160 *value = val;
161 err = 0;
162
163 fail:
164 mutex_unlock(&sat->mutex);
165 return err;
166 }
167
wf_sat_release(struct kref * ref)168 static void wf_sat_release(struct kref *ref)
169 {
170 struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
171
172 if (sat->nr >= 0)
173 sats[sat->nr] = NULL;
174 of_node_put(sat->node);
175 kfree(sat);
176 }
177
wf_sat_sensor_release(struct wf_sensor * sr)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
wf_sat_probe(struct i2c_client * client)193 static int wf_sat_probe(struct i2c_client *client)
194 {
195 struct device_node *dev = client->dev.of_node;
196 struct wf_sat *sat;
197 struct wf_sat_sensor *sens;
198 const u32 *reg;
199 const char *loc;
200 u8 chip, core;
201 struct device_node *child;
202 int shift, cpu, index;
203 char *name;
204 int vsens[2], isens[2];
205
206 sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
207 if (sat == NULL)
208 return -ENOMEM;
209 sat->nr = -1;
210 sat->node = of_node_get(dev);
211 kref_init(&sat->ref);
212 mutex_init(&sat->mutex);
213 sat->i2c = client;
214 INIT_LIST_HEAD(&sat->sensors);
215 i2c_set_clientdata(client, sat);
216
217 vsens[0] = vsens[1] = -1;
218 isens[0] = isens[1] = -1;
219 for_each_child_of_node(dev, child) {
220 reg = of_get_property(child, "reg", NULL);
221 loc = of_get_property(child, "location", NULL);
222 if (reg == NULL || loc == NULL)
223 continue;
224
225 /* the cooked sensors are between 0x30 and 0x37 */
226 if (*reg < 0x30 || *reg > 0x37)
227 continue;
228 index = *reg - 0x30;
229
230 /* expect location to be CPU [AB][01] ... */
231 if (strncmp(loc, "CPU ", 4) != 0)
232 continue;
233 chip = loc[4] - 'A';
234 core = loc[5] - '0';
235 if (chip > 1 || core > 1) {
236 printk(KERN_ERR "wf_sat_create: don't understand "
237 "location %s for %pOF\n", loc, child);
238 continue;
239 }
240 cpu = 2 * chip + core;
241 if (sat->nr < 0)
242 sat->nr = chip;
243 else if (sat->nr != chip) {
244 printk(KERN_ERR "wf_sat_create: can't cope with "
245 "multiple CPU chips on one SAT (%s)\n", loc);
246 continue;
247 }
248
249 if (of_node_is_type(child, "voltage-sensor")) {
250 name = "cpu-voltage";
251 shift = 4;
252 vsens[core] = index;
253 } else if (of_node_is_type(child, "current-sensor")) {
254 name = "cpu-current";
255 shift = 8;
256 isens[core] = index;
257 } else if (of_node_is_type(child, "temp-sensor")) {
258 name = "cpu-temp";
259 shift = 10;
260 } else
261 continue; /* hmmm shouldn't happen */
262
263 /* the +16 is enough for "cpu-voltage-n" */
264 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
265 if (sens == NULL) {
266 printk(KERN_ERR "wf_sat_create: couldn't create "
267 "%s sensor %d (no memory)\n", name, cpu);
268 continue;
269 }
270 sens->index = index;
271 sens->index2 = -1;
272 sens->shift = shift;
273 sens->sat = sat;
274 sens->sens.ops = &wf_sat_ops;
275 sens->sens.name = (char *) (sens + 1);
276 snprintf((char *)sens->sens.name, 16, "%s-%d", name, cpu);
277
278 if (wf_register_sensor(&sens->sens))
279 kfree(sens);
280 else {
281 list_add(&sens->link, &sat->sensors);
282 kref_get(&sat->ref);
283 }
284 }
285
286 /* make the power sensors */
287 for (core = 0; core < 2; ++core) {
288 if (vsens[core] < 0 || isens[core] < 0)
289 continue;
290 cpu = 2 * sat->nr + core;
291 sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
292 if (sens == NULL) {
293 printk(KERN_ERR "wf_sat_create: couldn't create power "
294 "sensor %d (no memory)\n", cpu);
295 continue;
296 }
297 sens->index = vsens[core];
298 sens->index2 = isens[core];
299 sens->shift = 0;
300 sens->sat = sat;
301 sens->sens.ops = &wf_sat_ops;
302 sens->sens.name = (char *) (sens + 1);
303 snprintf((char *)sens->sens.name, 16, "cpu-power-%d", cpu);
304
305 if (wf_register_sensor(&sens->sens))
306 kfree(sens);
307 else {
308 list_add(&sens->link, &sat->sensors);
309 kref_get(&sat->ref);
310 }
311 }
312
313 if (sat->nr >= 0)
314 sats[sat->nr] = sat;
315
316 return 0;
317 }
318
wf_sat_remove(struct i2c_client * client)319 static void wf_sat_remove(struct i2c_client *client)
320 {
321 struct wf_sat *sat = i2c_get_clientdata(client);
322 struct wf_sat_sensor *sens;
323
324 /* release sensors */
325 while(!list_empty(&sat->sensors)) {
326 sens = list_first_entry(&sat->sensors,
327 struct wf_sat_sensor, link);
328 list_del(&sens->link);
329 wf_unregister_sensor(&sens->sens);
330 }
331 sat->i2c = NULL;
332 kref_put(&sat->ref, wf_sat_release);
333 }
334
335 static const struct i2c_device_id wf_sat_id[] = {
336 { "MAC,smu-sat" },
337 { }
338 };
339 MODULE_DEVICE_TABLE(i2c, wf_sat_id);
340
341 static const struct of_device_id wf_sat_of_id[] = {
342 { .compatible = "smu-sat", },
343 { }
344 };
345 MODULE_DEVICE_TABLE(of, wf_sat_of_id);
346
347 static struct i2c_driver wf_sat_driver = {
348 .driver = {
349 .name = "wf_smu_sat",
350 .of_match_table = wf_sat_of_id,
351 },
352 .probe = wf_sat_probe,
353 .remove = wf_sat_remove,
354 .id_table = wf_sat_id,
355 };
356
357 module_i2c_driver(wf_sat_driver);
358
359 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
360 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
361 MODULE_LICENSE("GPL");
362