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
27struct 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
38static struct wf_sat *sats[2];
39
40struct 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
51struct 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}
112EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
113
114/* refresh the cache */
115static 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
135static 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
168static 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
178static 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
187static 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
193static 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
319static 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
335static const struct i2c_device_id wf_sat_id[] = {
336	{ "MAC,smu-sat", 0 },
337	{ }
338};
339MODULE_DEVICE_TABLE(i2c, wf_sat_id);
340
341static const struct of_device_id wf_sat_of_id[] = {
342	{ .compatible = "smu-sat", },
343	{ }
344};
345MODULE_DEVICE_TABLE(of, wf_sat_of_id);
346
347static 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
357module_i2c_driver(wf_sat_driver);
358
359MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
360MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
361MODULE_LICENSE("GPL");
362