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v3.1
 
  1/*
  2 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
  3 *
  4 * Copyright (c) 2010  Ericsson AB.
  5 *
  6 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
  7 *
  8 * JC42.4 compliant temperature sensors are typically used on memory modules.
  9 *
 10 * This program is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License as published by
 12 * the Free Software Foundation; either version 2 of the License, or
 13 * (at your option) any later version.
 14 *
 15 * This program is distributed in the hope that it will be useful,
 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18 * GNU General Public License for more details.
 19 *
 20 * You should have received a copy of the GNU General Public License
 21 * along with this program; if not, write to the Free Software
 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 23 */
 24
 
 
 25#include <linux/module.h>
 26#include <linux/init.h>
 27#include <linux/slab.h>
 28#include <linux/jiffies.h>
 29#include <linux/i2c.h>
 30#include <linux/hwmon.h>
 31#include <linux/hwmon-sysfs.h>
 32#include <linux/err.h>
 33#include <linux/mutex.h>
 
 
 34
 35/* Addresses to scan */
 36static const unsigned short normal_i2c[] = {
 37	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
 38
 39/* JC42 registers. All registers are 16 bit. */
 40#define JC42_REG_CAP		0x00
 41#define JC42_REG_CONFIG		0x01
 42#define JC42_REG_TEMP_UPPER	0x02
 43#define JC42_REG_TEMP_LOWER	0x03
 44#define JC42_REG_TEMP_CRITICAL	0x04
 45#define JC42_REG_TEMP		0x05
 46#define JC42_REG_MANID		0x06
 47#define JC42_REG_DEVICEID	0x07
 
 48
 49/* Status bits in temperature register */
 50#define JC42_ALARM_CRIT_BIT	15
 51#define JC42_ALARM_MAX_BIT	14
 52#define JC42_ALARM_MIN_BIT	13
 53
 54/* Configuration register defines */
 55#define JC42_CFG_CRIT_ONLY	(1 << 2)
 56#define JC42_CFG_TCRIT_LOCK	(1 << 6)
 57#define JC42_CFG_EVENT_LOCK	(1 << 7)
 58#define JC42_CFG_SHUTDOWN	(1 << 8)
 59#define JC42_CFG_HYST_SHIFT	9
 60#define JC42_CFG_HYST_MASK	0x03
 61
 62/* Capabilities */
 63#define JC42_CAP_RANGE		(1 << 2)
 64
 65/* Manufacturer IDs */
 66#define ADT_MANID		0x11d4  /* Analog Devices */
 
 
 67#define MAX_MANID		0x004d  /* Maxim */
 68#define IDT_MANID		0x00b3  /* IDT */
 69#define MCP_MANID		0x0054  /* Microchip */
 70#define NXP_MANID		0x1131  /* NXP Semiconductors */
 71#define ONS_MANID		0x1b09  /* ON Semiconductor */
 72#define STM_MANID		0x104a  /* ST Microelectronics */
 
 
 
 
 
 
 73
 74/* Supported chips */
 75
 76/* Analog Devices */
 77#define ADT7408_DEVID		0x0801
 78#define ADT7408_DEVID_MASK	0xffff
 79
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 80/* IDT */
 81#define TS3000B3_DEVID		0x2903  /* Also matches TSE2002B3 */
 82#define TS3000B3_DEVID_MASK	0xffff
 
 
 
 
 
 
 83
 84/* Maxim */
 85#define MAX6604_DEVID		0x3e00
 86#define MAX6604_DEVID_MASK	0xffff
 87
 88/* Microchip */
 
 
 
 
 
 
 89#define MCP98242_DEVID		0x2000
 90#define MCP98242_DEVID_MASK	0xfffc
 91
 92#define MCP98243_DEVID		0x2100
 93#define MCP98243_DEVID_MASK	0xfffc
 94
 
 
 
 95#define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
 96#define MCP9843_DEVID_MASK	0xfffe
 97
 98/* NXP */
 99#define SE97_DEVID		0xa200
100#define SE97_DEVID_MASK		0xfffc
101
102#define SE98_DEVID		0xa100
103#define SE98_DEVID_MASK		0xfffc
104
105/* ON Semiconductor */
106#define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
107#define CAT6095_DEVID_MASK	0xffe0
108
 
 
 
 
 
 
 
 
 
109/* ST Microelectronics */
110#define STTS424_DEVID		0x0101
111#define STTS424_DEVID_MASK	0xffff
112
113#define STTS424E_DEVID		0x0000
114#define STTS424E_DEVID_MASK	0xfffe
115
 
 
 
 
 
 
 
 
 
 
 
 
 
116static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
117
118struct jc42_chips {
119	u16 manid;
120	u16 devid;
121	u16 devid_mask;
122};
123
124static struct jc42_chips jc42_chips[] = {
125	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
126	{ IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
 
 
 
 
 
 
127	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
 
 
128	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
129	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
 
130	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
131	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
132	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
 
 
 
133	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
 
134	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
135	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
 
 
 
136};
137
138/* Each client has this additional data */
139struct jc42_data {
140	struct device	*hwmon_dev;
141	struct mutex	update_lock;	/* protect register access */
 
142	bool		extended;	/* true if extended range supported */
143	bool		valid;
144	unsigned long	last_updated;	/* In jiffies */
145	u16		orig_config;	/* original configuration */
146	u16		config;		/* current configuration */
147	u16		temp_input;	/* Temperatures */
148	u16		temp_crit;
149	u16		temp_min;
150	u16		temp_max;
151};
152
153static int jc42_probe(struct i2c_client *client,
154		      const struct i2c_device_id *id);
155static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
156static int jc42_remove(struct i2c_client *client);
157static int jc42_read_value(struct i2c_client *client, u8 reg);
158static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value);
159
160static struct jc42_data *jc42_update_device(struct device *dev);
161
162static const struct i2c_device_id jc42_id[] = {
163	{ "adt7408", 0 },
164	{ "cat94ts02", 0 },
165	{ "cat6095", 0 },
166	{ "jc42", 0 },
167	{ "max6604", 0 },
168	{ "mcp9805", 0 },
169	{ "mcp98242", 0 },
170	{ "mcp98243", 0 },
171	{ "mcp9843", 0 },
172	{ "se97", 0 },
173	{ "se97b", 0 },
174	{ "se98", 0 },
175	{ "stts424", 0 },
176	{ "tse2002b3", 0 },
177	{ "ts3000b3", 0 },
178	{ }
179};
180MODULE_DEVICE_TABLE(i2c, jc42_id);
181
182#ifdef CONFIG_PM
183
184static int jc42_suspend(struct device *dev)
185{
186	struct i2c_client *client = to_i2c_client(dev);
187	struct jc42_data *data = i2c_get_clientdata(client);
188
189	data->config |= JC42_CFG_SHUTDOWN;
190	jc42_write_value(client, JC42_REG_CONFIG, data->config);
191	return 0;
192}
193
194static int jc42_resume(struct device *dev)
195{
196	struct i2c_client *client = to_i2c_client(dev);
197	struct jc42_data *data = i2c_get_clientdata(client);
198
199	data->config &= ~JC42_CFG_SHUTDOWN;
200	jc42_write_value(client, JC42_REG_CONFIG, data->config);
201	return 0;
202}
203
204static const struct dev_pm_ops jc42_dev_pm_ops = {
205	.suspend = jc42_suspend,
206	.resume = jc42_resume,
207};
208
209#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
210#else
211#define JC42_DEV_PM_OPS NULL
212#endif /* CONFIG_PM */
213
214/* This is the driver that will be inserted */
215static struct i2c_driver jc42_driver = {
216	.class		= I2C_CLASS_SPD,
217	.driver = {
218		.name	= "jc42",
219		.pm = JC42_DEV_PM_OPS,
220	},
221	.probe		= jc42_probe,
222	.remove		= jc42_remove,
223	.id_table	= jc42_id,
224	.detect		= jc42_detect,
225	.address_list	= normal_i2c,
226};
227
228#define JC42_TEMP_MIN_EXTENDED	(-40000)
229#define JC42_TEMP_MIN		0
230#define JC42_TEMP_MAX		125000
231
232static u16 jc42_temp_to_reg(int temp, bool extended)
233{
234	int ntemp = SENSORS_LIMIT(temp,
235				  extended ? JC42_TEMP_MIN_EXTENDED :
236				  JC42_TEMP_MIN, JC42_TEMP_MAX);
237
238	/* convert from 0.001 to 0.0625 resolution */
239	return (ntemp * 2 / 125) & 0x1fff;
240}
241
242static int jc42_temp_from_reg(s16 reg)
243{
244	reg &= 0x1fff;
245
246	/* sign extend register */
247	if (reg & 0x1000)
248		reg |= 0xf000;
249
250	/* convert from 0.0625 to 0.001 resolution */
251	return reg * 125 / 2;
252}
253
254/* sysfs stuff */
255
256/* read routines for temperature limits */
257#define show(value)	\
258static ssize_t show_##value(struct device *dev,				\
259			    struct device_attribute *attr,		\
260			    char *buf)					\
261{									\
262	struct jc42_data *data = jc42_update_device(dev);		\
263	if (IS_ERR(data))						\
264		return PTR_ERR(data);					\
265	return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));	\
266}
267
268show(temp_input);
269show(temp_crit);
270show(temp_min);
271show(temp_max);
272
273/* read routines for hysteresis values */
274static ssize_t show_temp_crit_hyst(struct device *dev,
275				   struct device_attribute *attr, char *buf)
276{
277	struct jc42_data *data = jc42_update_device(dev);
278	int temp, hyst;
279
280	if (IS_ERR(data))
281		return PTR_ERR(data);
282
283	temp = jc42_temp_from_reg(data->temp_crit);
284	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
285			       & JC42_CFG_HYST_MASK];
286	return sprintf(buf, "%d\n", temp - hyst);
287}
288
289static ssize_t show_temp_max_hyst(struct device *dev,
290				  struct device_attribute *attr, char *buf)
291{
292	struct jc42_data *data = jc42_update_device(dev);
293	int temp, hyst;
294
295	if (IS_ERR(data))
296		return PTR_ERR(data);
297
298	temp = jc42_temp_from_reg(data->temp_max);
299	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
300			       & JC42_CFG_HYST_MASK];
301	return sprintf(buf, "%d\n", temp - hyst);
302}
303
304/* write routines */
305#define set(value, reg)	\
306static ssize_t set_##value(struct device *dev,				\
307			   struct device_attribute *attr,		\
308			   const char *buf, size_t count)		\
309{									\
310	struct i2c_client *client = to_i2c_client(dev);			\
311	struct jc42_data *data = i2c_get_clientdata(client);		\
312	int err, ret = count;						\
313	long val;							\
314	if (strict_strtol(buf, 10, &val) < 0)				\
315		return -EINVAL;						\
316	mutex_lock(&data->update_lock);					\
317	data->value = jc42_temp_to_reg(val, data->extended);		\
318	err = jc42_write_value(client, reg, data->value);		\
319	if (err < 0)							\
320		ret = err;						\
321	mutex_unlock(&data->update_lock);				\
322	return ret;							\
323}
324
325set(temp_min, JC42_REG_TEMP_LOWER);
326set(temp_max, JC42_REG_TEMP_UPPER);
327set(temp_crit, JC42_REG_TEMP_CRITICAL);
328
329/* JC42.4 compliant chips only support four hysteresis values.
330 * Pick best choice and go from there. */
331static ssize_t set_temp_crit_hyst(struct device *dev,
332				  struct device_attribute *attr,
333				  const char *buf, size_t count)
334{
335	struct i2c_client *client = to_i2c_client(dev);
336	struct jc42_data *data = i2c_get_clientdata(client);
337	unsigned long val;
338	int diff, hyst;
339	int err;
340	int ret = count;
341
342	if (strict_strtoul(buf, 10, &val) < 0)
343		return -EINVAL;
344
345	diff = jc42_temp_from_reg(data->temp_crit) - val;
346	hyst = 0;
347	if (diff > 0) {
348		if (diff < 2250)
349			hyst = 1;	/* 1.5 degrees C */
350		else if (diff < 4500)
351			hyst = 2;	/* 3.0 degrees C */
352		else
353			hyst = 3;	/* 6.0 degrees C */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
354	}
355
356	mutex_lock(&data->update_lock);
357	data->config = (data->config
358			& ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
359	  | (hyst << JC42_CFG_HYST_SHIFT);
360	err = jc42_write_value(client, JC42_REG_CONFIG, data->config);
361	if (err < 0)
362		ret = err;
363	mutex_unlock(&data->update_lock);
 
364	return ret;
365}
366
367static ssize_t show_alarm(struct device *dev,
368			  struct device_attribute *attr, char *buf)
369{
370	u16 bit = to_sensor_dev_attr(attr)->index;
371	struct jc42_data *data = jc42_update_device(dev);
372	u16 val;
373
374	if (IS_ERR(data))
375		return PTR_ERR(data);
376
377	val = data->temp_input;
378	if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
379		val = 0;
380	return sprintf(buf, "%u\n", (val >> bit) & 1);
381}
382
383static DEVICE_ATTR(temp1_input, S_IRUGO,
384		   show_temp_input, NULL);
385static DEVICE_ATTR(temp1_crit, S_IRUGO,
386		   show_temp_crit, set_temp_crit);
387static DEVICE_ATTR(temp1_min, S_IRUGO,
388		   show_temp_min, set_temp_min);
389static DEVICE_ATTR(temp1_max, S_IRUGO,
390		   show_temp_max, set_temp_max);
391
392static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
393		   show_temp_crit_hyst, set_temp_crit_hyst);
394static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
395		   show_temp_max_hyst, NULL);
396
397static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
398			  JC42_ALARM_CRIT_BIT);
399static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
400			  JC42_ALARM_MIN_BIT);
401static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
402			  JC42_ALARM_MAX_BIT);
403
404static struct attribute *jc42_attributes[] = {
405	&dev_attr_temp1_input.attr,
406	&dev_attr_temp1_crit.attr,
407	&dev_attr_temp1_min.attr,
408	&dev_attr_temp1_max.attr,
409	&dev_attr_temp1_crit_hyst.attr,
410	&dev_attr_temp1_max_hyst.attr,
411	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
412	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
413	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
414	NULL
415};
416
417static mode_t jc42_attribute_mode(struct kobject *kobj,
418				  struct attribute *attr, int index)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
419{
420	struct device *dev = container_of(kobj, struct device, kobj);
421	struct i2c_client *client = to_i2c_client(dev);
422	struct jc42_data *data = i2c_get_clientdata(client);
423	unsigned int config = data->config;
424	bool readonly;
425
426	if (attr == &dev_attr_temp1_crit.attr)
427		readonly = config & JC42_CFG_TCRIT_LOCK;
428	else if (attr == &dev_attr_temp1_min.attr ||
429		 attr == &dev_attr_temp1_max.attr)
430		readonly = config & JC42_CFG_EVENT_LOCK;
431	else if (attr == &dev_attr_temp1_crit_hyst.attr)
432		readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
433	else
434		readonly = true;
435
436	return S_IRUGO | (readonly ? 0 : S_IWUSR);
437}
438
439static const struct attribute_group jc42_group = {
440	.attrs = jc42_attributes,
441	.is_visible = jc42_attribute_mode,
442};
 
 
 
 
 
 
 
 
 
443
444/* Return 0 if detection is successful, -ENODEV otherwise */
445static int jc42_detect(struct i2c_client *new_client,
446		       struct i2c_board_info *info)
447{
448	struct i2c_adapter *adapter = new_client->adapter;
449	int i, config, cap, manid, devid;
450
451	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
452				     I2C_FUNC_SMBUS_WORD_DATA))
453		return -ENODEV;
454
455	cap = jc42_read_value(new_client, JC42_REG_CAP);
456	config = jc42_read_value(new_client, JC42_REG_CONFIG);
457	manid = jc42_read_value(new_client, JC42_REG_MANID);
458	devid = jc42_read_value(new_client, JC42_REG_DEVICEID);
459
460	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
461		return -ENODEV;
462
463	if ((cap & 0xff00) || (config & 0xf800))
464		return -ENODEV;
465
466	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
467		struct jc42_chips *chip = &jc42_chips[i];
468		if (manid == chip->manid &&
469		    (devid & chip->devid_mask) == chip->devid) {
470			strlcpy(info->type, "jc42", I2C_NAME_SIZE);
471			return 0;
472		}
473	}
474	return -ENODEV;
475}
476
477static int jc42_probe(struct i2c_client *new_client,
478		      const struct i2c_device_id *id)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
479{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
480	struct jc42_data *data;
481	int config, cap, err;
482
483	data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
484	if (!data) {
485		err = -ENOMEM;
486		goto exit;
487	}
 
 
488
489	i2c_set_clientdata(new_client, data);
490	mutex_init(&data->update_lock);
491
492	cap = jc42_read_value(new_client, JC42_REG_CAP);
493	if (cap < 0) {
494		err = -EINVAL;
495		goto exit_free;
496	}
497	data->extended = !!(cap & JC42_CAP_RANGE);
498
499	config = jc42_read_value(new_client, JC42_REG_CONFIG);
500	if (config < 0) {
501		err = -EINVAL;
502		goto exit_free;
 
 
 
 
 
 
 
503	}
 
 
 
 
 
504	data->orig_config = config;
505	if (config & JC42_CFG_SHUTDOWN) {
506		config &= ~JC42_CFG_SHUTDOWN;
507		jc42_write_value(new_client, JC42_REG_CONFIG, config);
508	}
509	data->config = config;
510
511	/* Register sysfs hooks */
512	err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
513	if (err)
514		goto exit_free;
515
516	data->hwmon_dev = hwmon_device_register(&new_client->dev);
517	if (IS_ERR(data->hwmon_dev)) {
518		err = PTR_ERR(data->hwmon_dev);
519		goto exit_remove;
520	}
521
522	return 0;
523
524exit_remove:
525	sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
526exit_free:
527	kfree(data);
528exit:
529	return err;
530}
531
532static int jc42_remove(struct i2c_client *client)
533{
534	struct jc42_data *data = i2c_get_clientdata(client);
535	hwmon_device_unregister(data->hwmon_dev);
536	sysfs_remove_group(&client->dev.kobj, &jc42_group);
537	if (data->config != data->orig_config)
538		jc42_write_value(client, JC42_REG_CONFIG, data->orig_config);
539	kfree(data);
540	return 0;
541}
542
543/* All registers are word-sized. */
544static int jc42_read_value(struct i2c_client *client, u8 reg)
545{
546	int ret = i2c_smbus_read_word_data(client, reg);
547	if (ret < 0)
548		return ret;
549	return swab16(ret);
 
 
550}
551
552static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value)
 
 
553{
554	return i2c_smbus_write_word_data(client, reg, swab16(value));
 
 
 
 
 
 
 
 
555}
556
557static struct jc42_data *jc42_update_device(struct device *dev)
558{
559	struct i2c_client *client = to_i2c_client(dev);
560	struct jc42_data *data = i2c_get_clientdata(client);
561	struct jc42_data *ret = data;
562	int val;
563
564	mutex_lock(&data->update_lock);
565
566	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
567		val = jc42_read_value(client, JC42_REG_TEMP);
568		if (val < 0) {
569			ret = ERR_PTR(val);
570			goto abort;
571		}
572		data->temp_input = val;
573
574		val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL);
575		if (val < 0) {
576			ret = ERR_PTR(val);
577			goto abort;
578		}
579		data->temp_crit = val;
580
581		val = jc42_read_value(client, JC42_REG_TEMP_LOWER);
582		if (val < 0) {
583			ret = ERR_PTR(val);
584			goto abort;
585		}
586		data->temp_min = val;
587
588		val = jc42_read_value(client, JC42_REG_TEMP_UPPER);
589		if (val < 0) {
590			ret = ERR_PTR(val);
591			goto abort;
592		}
593		data->temp_max = val;
594
595		data->last_updated = jiffies;
596		data->valid = true;
597	}
598abort:
599	mutex_unlock(&data->update_lock);
600	return ret;
601}
602
603static int __init sensors_jc42_init(void)
604{
605	return i2c_add_driver(&jc42_driver);
606}
 
 
 
607
608static void __exit sensors_jc42_exit(void)
609{
610	i2c_del_driver(&jc42_driver);
611}
 
 
 
 
 
 
 
 
 
612
613MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
 
 
614MODULE_DESCRIPTION("JC42 driver");
615MODULE_LICENSE("GPL");
616
617module_init(sensors_jc42_init);
618module_exit(sensors_jc42_exit);
v6.8
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
  4 *
  5 * Copyright (c) 2010  Ericsson AB.
  6 *
  7 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
  8 *
  9 * JC42.4 compliant temperature sensors are typically used on memory modules.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 10 */
 11
 12#include <linux/bitops.h>
 13#include <linux/bitfield.h>
 14#include <linux/module.h>
 15#include <linux/init.h>
 16#include <linux/slab.h>
 17#include <linux/jiffies.h>
 18#include <linux/i2c.h>
 19#include <linux/hwmon.h>
 
 20#include <linux/err.h>
 21#include <linux/mutex.h>
 22#include <linux/of.h>
 23#include <linux/regmap.h>
 24
 25/* Addresses to scan */
 26static const unsigned short normal_i2c[] = {
 27	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
 28
 29/* JC42 registers. All registers are 16 bit. */
 30#define JC42_REG_CAP		0x00
 31#define JC42_REG_CONFIG		0x01
 32#define JC42_REG_TEMP_UPPER	0x02
 33#define JC42_REG_TEMP_LOWER	0x03
 34#define JC42_REG_TEMP_CRITICAL	0x04
 35#define JC42_REG_TEMP		0x05
 36#define JC42_REG_MANID		0x06
 37#define JC42_REG_DEVICEID	0x07
 38#define JC42_REG_SMBUS		0x22 /* NXP and Atmel, possibly others? */
 39
 40/* Status bits in temperature register */
 41#define JC42_ALARM_CRIT		BIT(15)
 42#define JC42_ALARM_MAX		BIT(14)
 43#define JC42_ALARM_MIN		BIT(13)
 44
 45/* Configuration register defines */
 46#define JC42_CFG_CRIT_ONLY	BIT(2)
 47#define JC42_CFG_TCRIT_LOCK	BIT(6)
 48#define JC42_CFG_EVENT_LOCK	BIT(7)
 49#define JC42_CFG_SHUTDOWN	BIT(8)
 50#define JC42_CFG_HYST_MASK	GENMASK(10, 9)
 
 51
 52/* Capabilities */
 53#define JC42_CAP_RANGE		BIT(2)
 54
 55/* Manufacturer IDs */
 56#define ADT_MANID		0x11d4  /* Analog Devices */
 57#define ATMEL_MANID		0x001f  /* Atmel */
 58#define ATMEL_MANID2		0x1114	/* Atmel */
 59#define MAX_MANID		0x004d  /* Maxim */
 60#define IDT_MANID		0x00b3  /* IDT */
 61#define MCP_MANID		0x0054  /* Microchip */
 62#define NXP_MANID		0x1131  /* NXP Semiconductors */
 63#define ONS_MANID		0x1b09  /* ON Semiconductor */
 64#define STM_MANID		0x104a  /* ST Microelectronics */
 65#define GT_MANID		0x1c68	/* Giantec */
 66#define GT_MANID2		0x132d	/* Giantec, 2nd mfg ID */
 67#define SI_MANID		0x1c85	/* Seiko Instruments */
 68
 69/* SMBUS register */
 70#define SMBUS_STMOUT		BIT(7)  /* SMBus time-out, active low */
 71
 72/* Supported chips */
 73
 74/* Analog Devices */
 75#define ADT7408_DEVID		0x0801
 76#define ADT7408_DEVID_MASK	0xffff
 77
 78/* Atmel */
 79#define AT30TS00_DEVID		0x8201
 80#define AT30TS00_DEVID_MASK	0xffff
 81
 82#define AT30TSE004_DEVID	0x2200
 83#define AT30TSE004_DEVID_MASK	0xffff
 84
 85/* Giantec */
 86#define GT30TS00_DEVID		0x2200
 87#define GT30TS00_DEVID_MASK	0xff00
 88
 89#define GT34TS02_DEVID		0x3300
 90#define GT34TS02_DEVID_MASK	0xff00
 91
 92/* IDT */
 93#define TSE2004_DEVID		0x2200
 94#define TSE2004_DEVID_MASK	0xff00
 95
 96#define TS3000_DEVID		0x2900  /* Also matches TSE2002 */
 97#define TS3000_DEVID_MASK	0xff00
 98
 99#define TS3001_DEVID		0x3000
100#define TS3001_DEVID_MASK	0xff00
101
102/* Maxim */
103#define MAX6604_DEVID		0x3e00
104#define MAX6604_DEVID_MASK	0xffff
105
106/* Microchip */
107#define MCP9804_DEVID		0x0200
108#define MCP9804_DEVID_MASK	0xfffc
109
110#define MCP9808_DEVID		0x0400
111#define MCP9808_DEVID_MASK	0xfffc
112
113#define MCP98242_DEVID		0x2000
114#define MCP98242_DEVID_MASK	0xfffc
115
116#define MCP98243_DEVID		0x2100
117#define MCP98243_DEVID_MASK	0xfffc
118
119#define MCP98244_DEVID		0x2200
120#define MCP98244_DEVID_MASK	0xfffc
121
122#define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
123#define MCP9843_DEVID_MASK	0xfffe
124
125/* NXP */
126#define SE97_DEVID		0xa200
127#define SE97_DEVID_MASK		0xfffc
128
129#define SE98_DEVID		0xa100
130#define SE98_DEVID_MASK		0xfffc
131
132/* ON Semiconductor */
133#define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
134#define CAT6095_DEVID_MASK	0xffe0
135
136#define CAT34TS02C_DEVID	0x0a00
137#define CAT34TS02C_DEVID_MASK	0xfff0
138
139#define CAT34TS04_DEVID		0x2200
140#define CAT34TS04_DEVID_MASK	0xfff0
141
142#define N34TS04_DEVID		0x2230
143#define N34TS04_DEVID_MASK	0xfff0
144
145/* ST Microelectronics */
146#define STTS424_DEVID		0x0101
147#define STTS424_DEVID_MASK	0xffff
148
149#define STTS424E_DEVID		0x0000
150#define STTS424E_DEVID_MASK	0xfffe
151
152#define STTS2002_DEVID		0x0300
153#define STTS2002_DEVID_MASK	0xffff
154
155#define STTS2004_DEVID		0x2201
156#define STTS2004_DEVID_MASK	0xffff
157
158#define STTS3000_DEVID		0x0200
159#define STTS3000_DEVID_MASK	0xffff
160
161/* Seiko Instruments */
162#define S34TS04A_DEVID		0x2221
163#define S34TS04A_DEVID_MASK	0xffff
164
165static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
166
167struct jc42_chips {
168	u16 manid;
169	u16 devid;
170	u16 devid_mask;
171};
172
173static struct jc42_chips jc42_chips[] = {
174	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
175	{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
176	{ ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
177	{ GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
178	{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
179	{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
180	{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
181	{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
182	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
183	{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
184	{ MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
185	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
186	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
187	{ MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
188	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
189	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
190	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
191	{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
192	{ ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK },
193	{ ONS_MANID, N34TS04_DEVID, N34TS04_DEVID_MASK },
194	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
195	{ SI_MANID,  S34TS04A_DEVID, S34TS04A_DEVID_MASK },
196	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
197	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
198	{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
199	{ STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
200	{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
201};
202
203/* Each client has this additional data */
204struct jc42_data {
 
205	struct mutex	update_lock;	/* protect register access */
206	struct regmap	*regmap;
207	bool		extended;	/* true if extended range supported */
208	bool		valid;
 
209	u16		orig_config;	/* original configuration */
210	u16		config;		/* current configuration */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
211};
212
213#define JC42_TEMP_MIN_EXTENDED	(-40000)
214#define JC42_TEMP_MIN		0
215#define JC42_TEMP_MAX		125000
216
217static u16 jc42_temp_to_reg(long temp, bool extended)
218{
219	int ntemp = clamp_val(temp,
220			      extended ? JC42_TEMP_MIN_EXTENDED :
221			      JC42_TEMP_MIN, JC42_TEMP_MAX);
222
223	/* convert from 0.001 to 0.0625 resolution */
224	return (ntemp * 2 / 125) & 0x1fff;
225}
226
227static int jc42_temp_from_reg(s16 reg)
228{
229	reg = sign_extend32(reg, 12);
 
 
 
 
230
231	/* convert from 0.0625 to 0.001 resolution */
232	return reg * 125 / 2;
233}
234
235static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
236		     u32 attr, int channel, long *val)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
237{
238	struct jc42_data *data = dev_get_drvdata(dev);
239	unsigned int regval;
240	int ret, temp, hyst;
 
 
 
241
242	mutex_lock(&data->update_lock);
 
243
244	switch (attr) {
245	case hwmon_temp_input:
246		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
247		if (ret)
248			break;
249
250		*val = jc42_temp_from_reg(regval);
251		break;
252	case hwmon_temp_min:
253		ret = regmap_read(data->regmap, JC42_REG_TEMP_LOWER, &regval);
254		if (ret)
255			break;
256
257		*val = jc42_temp_from_reg(regval);
258		break;
259	case hwmon_temp_max:
260		ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, &regval);
261		if (ret)
262			break;
263
264		*val = jc42_temp_from_reg(regval);
265		break;
266	case hwmon_temp_crit:
267		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
268				  &regval);
269		if (ret)
270			break;
271
272		*val = jc42_temp_from_reg(regval);
273		break;
274	case hwmon_temp_max_hyst:
275		ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, &regval);
276		if (ret)
277			break;
278
279		temp = jc42_temp_from_reg(regval);
280		hyst = jc42_hysteresis[FIELD_GET(JC42_CFG_HYST_MASK,
281						 data->config)];
282		*val = temp - hyst;
283		break;
284	case hwmon_temp_crit_hyst:
285		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
286				  &regval);
287		if (ret)
288			break;
289
290		temp = jc42_temp_from_reg(regval);
291		hyst = jc42_hysteresis[FIELD_GET(JC42_CFG_HYST_MASK,
292						 data->config)];
293		*val = temp - hyst;
294		break;
295	case hwmon_temp_min_alarm:
296		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
297		if (ret)
298			break;
299
300		*val = FIELD_GET(JC42_ALARM_MIN, regval);
301		break;
302	case hwmon_temp_max_alarm:
303		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
304		if (ret)
305			break;
306
307		*val = FIELD_GET(JC42_ALARM_MAX, regval);
308		break;
309	case hwmon_temp_crit_alarm:
310		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
311		if (ret)
312			break;
313
314		*val = FIELD_GET(JC42_ALARM_CRIT, regval);
315		break;
316	default:
317		ret = -EOPNOTSUPP;
318		break;
319	}
320
 
 
 
 
 
 
 
321	mutex_unlock(&data->update_lock);
322
323	return ret;
324}
325
326static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
327		      u32 attr, int channel, long val)
328{
329	struct jc42_data *data = dev_get_drvdata(dev);
330	unsigned int regval;
331	int diff, hyst;
332	int ret;
333
334	mutex_lock(&data->update_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
335
336	switch (attr) {
337	case hwmon_temp_min:
338		ret = regmap_write(data->regmap, JC42_REG_TEMP_LOWER,
339				   jc42_temp_to_reg(val, data->extended));
340		break;
341	case hwmon_temp_max:
342		ret = regmap_write(data->regmap, JC42_REG_TEMP_UPPER,
343				   jc42_temp_to_reg(val, data->extended));
344		break;
345	case hwmon_temp_crit:
346		ret = regmap_write(data->regmap, JC42_REG_TEMP_CRITICAL,
347				   jc42_temp_to_reg(val, data->extended));
348		break;
349	case hwmon_temp_crit_hyst:
350		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
351				  &regval);
352		if (ret)
353			break;
354
355		/*
356		 * JC42.4 compliant chips only support four hysteresis values.
357		 * Pick best choice and go from there.
358		 */
359		val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
360						     : JC42_TEMP_MIN) - 6000,
361				JC42_TEMP_MAX);
362		diff = jc42_temp_from_reg(regval) - val;
363		hyst = 0;
364		if (diff > 0) {
365			if (diff < 2250)
366				hyst = 1;	/* 1.5 degrees C */
367			else if (diff < 4500)
368				hyst = 2;	/* 3.0 degrees C */
369			else
370				hyst = 3;	/* 6.0 degrees C */
371		}
372		data->config = (data->config & ~JC42_CFG_HYST_MASK) |
373				FIELD_PREP(JC42_CFG_HYST_MASK, hyst);
374		ret = regmap_write(data->regmap, JC42_REG_CONFIG,
375				   data->config);
376		break;
377	default:
378		ret = -EOPNOTSUPP;
379		break;
380	}
381
382	mutex_unlock(&data->update_lock);
383
384	return ret;
385}
386
387static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
388			       u32 attr, int channel)
389{
390	const struct jc42_data *data = _data;
 
 
391	unsigned int config = data->config;
392	umode_t mode = 0444;
393
394	switch (attr) {
395	case hwmon_temp_min:
396	case hwmon_temp_max:
397		if (!(config & JC42_CFG_EVENT_LOCK))
398			mode |= 0200;
399		break;
400	case hwmon_temp_crit:
401		if (!(config & JC42_CFG_TCRIT_LOCK))
402			mode |= 0200;
403		break;
404	case hwmon_temp_crit_hyst:
405		if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
406			mode |= 0200;
407		break;
408	case hwmon_temp_input:
409	case hwmon_temp_max_hyst:
410	case hwmon_temp_min_alarm:
411	case hwmon_temp_max_alarm:
412	case hwmon_temp_crit_alarm:
413		break;
414	default:
415		mode = 0;
416		break;
417	}
418	return mode;
419}
420
421/* Return 0 if detection is successful, -ENODEV otherwise */
422static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
 
423{
424	struct i2c_adapter *adapter = client->adapter;
425	int i, config, cap, manid, devid;
426
427	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
428				     I2C_FUNC_SMBUS_WORD_DATA))
429		return -ENODEV;
430
431	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
432	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
433	manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
434	devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
435
436	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
437		return -ENODEV;
438
439	if ((cap & 0xff00) || (config & 0xf800))
440		return -ENODEV;
441
442	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
443		struct jc42_chips *chip = &jc42_chips[i];
444		if (manid == chip->manid &&
445		    (devid & chip->devid_mask) == chip->devid) {
446			strscpy(info->type, "jc42", I2C_NAME_SIZE);
447			return 0;
448		}
449	}
450	return -ENODEV;
451}
452
453static const struct hwmon_channel_info * const jc42_info[] = {
454	HWMON_CHANNEL_INFO(chip,
455			   HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
456	HWMON_CHANNEL_INFO(temp,
457			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
458			   HWMON_T_CRIT | HWMON_T_MAX_HYST |
459			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
460			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM),
461	NULL
462};
463
464static const struct hwmon_ops jc42_hwmon_ops = {
465	.is_visible = jc42_is_visible,
466	.read = jc42_read,
467	.write = jc42_write,
468};
469
470static const struct hwmon_chip_info jc42_chip_info = {
471	.ops = &jc42_hwmon_ops,
472	.info = jc42_info,
473};
474
475static bool jc42_readable_reg(struct device *dev, unsigned int reg)
476{
477	return (reg >= JC42_REG_CAP && reg <= JC42_REG_DEVICEID) ||
478		reg == JC42_REG_SMBUS;
479}
480
481static bool jc42_writable_reg(struct device *dev, unsigned int reg)
482{
483	return (reg >= JC42_REG_CONFIG && reg <= JC42_REG_TEMP_CRITICAL) ||
484		reg == JC42_REG_SMBUS;
485}
486
487static bool jc42_volatile_reg(struct device *dev, unsigned int reg)
488{
489	return reg == JC42_REG_CONFIG || reg == JC42_REG_TEMP;
490}
491
492static const struct regmap_config jc42_regmap_config = {
493	.reg_bits = 8,
494	.val_bits = 16,
495	.val_format_endian = REGMAP_ENDIAN_BIG,
496	.max_register = JC42_REG_SMBUS,
497	.writeable_reg = jc42_writable_reg,
498	.readable_reg = jc42_readable_reg,
499	.volatile_reg = jc42_volatile_reg,
500	.cache_type = REGCACHE_RBTREE,
501};
502
503static int jc42_probe(struct i2c_client *client)
504{
505	struct device *dev = &client->dev;
506	struct device *hwmon_dev;
507	unsigned int config, cap;
508	struct jc42_data *data;
509	int ret;
510
511	data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
512	if (!data)
513		return -ENOMEM;
514
515	data->regmap = devm_regmap_init_i2c(client, &jc42_regmap_config);
516	if (IS_ERR(data->regmap))
517		return PTR_ERR(data->regmap);
518
519	i2c_set_clientdata(client, data);
520	mutex_init(&data->update_lock);
521
522	ret = regmap_read(data->regmap, JC42_REG_CAP, &cap);
523	if (ret)
524		return ret;
525
 
526	data->extended = !!(cap & JC42_CAP_RANGE);
527
528	if (device_property_read_bool(dev, "smbus-timeout-disable")) {
529		/*
530		 * Not all chips support this register, but from a
531		 * quick read of various datasheets no chip appears
532		 * incompatible with the below attempt to disable
533		 * the timeout. And the whole thing is opt-in...
534		 */
535		ret = regmap_set_bits(data->regmap, JC42_REG_SMBUS,
536				      SMBUS_STMOUT);
537		if (ret)
538			return ret;
539	}
540
541	ret = regmap_read(data->regmap, JC42_REG_CONFIG, &config);
542	if (ret)
543		return ret;
544
545	data->orig_config = config;
546	if (config & JC42_CFG_SHUTDOWN) {
547		config &= ~JC42_CFG_SHUTDOWN;
548		regmap_write(data->regmap, JC42_REG_CONFIG, config);
549	}
550	data->config = config;
551
552	hwmon_dev = devm_hwmon_device_register_with_info(dev, "jc42",
553							 data, &jc42_chip_info,
554							 NULL);
555	return PTR_ERR_OR_ZERO(hwmon_dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
556}
557
558static void jc42_remove(struct i2c_client *client)
559{
560	struct jc42_data *data = i2c_get_clientdata(client);
 
 
 
 
 
 
 
561
562	/* Restore original configuration except hysteresis */
563	if ((data->config & ~JC42_CFG_HYST_MASK) !=
564	    (data->orig_config & ~JC42_CFG_HYST_MASK)) {
565		int config;
566
567		config = (data->orig_config & ~JC42_CFG_HYST_MASK)
568		  | (data->config & JC42_CFG_HYST_MASK);
569		regmap_write(data->regmap, JC42_REG_CONFIG, config);
570	}
571}
572
573#ifdef CONFIG_PM
574
575static int jc42_suspend(struct device *dev)
576{
577	struct jc42_data *data = dev_get_drvdata(dev);
578
579	data->config |= JC42_CFG_SHUTDOWN;
580	regmap_write(data->regmap, JC42_REG_CONFIG, data->config);
581
582	regcache_cache_only(data->regmap, true);
583	regcache_mark_dirty(data->regmap);
584
585	return 0;
586}
587
588static int jc42_resume(struct device *dev)
589{
590	struct jc42_data *data = dev_get_drvdata(dev);
 
 
 
591
592	regcache_cache_only(data->regmap, false);
593
594	data->config &= ~JC42_CFG_SHUTDOWN;
595	regmap_write(data->regmap, JC42_REG_CONFIG, data->config);
 
 
 
 
 
596
597	/* Restore cached register values to hardware */
598	return regcache_sync(data->regmap);
599}
 
 
 
600
601static const struct dev_pm_ops jc42_dev_pm_ops = {
602	.suspend = jc42_suspend,
603	.resume = jc42_resume,
604};
 
 
605
606#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
607#else
608#define JC42_DEV_PM_OPS NULL
609#endif /* CONFIG_PM */
 
 
610
611static const struct i2c_device_id jc42_id[] = {
612	{ "jc42", 0 },
613	{ }
614};
615MODULE_DEVICE_TABLE(i2c, jc42_id);
 
 
616
617#ifdef CONFIG_OF
618static const struct of_device_id jc42_of_ids[] = {
619	{ .compatible = "jedec,jc-42.4-temp", },
620	{ }
621};
622MODULE_DEVICE_TABLE(of, jc42_of_ids);
623#endif
624
625static struct i2c_driver jc42_driver = {
626	.class		= I2C_CLASS_SPD | I2C_CLASS_HWMON,
627	.driver = {
628		.name	= "jc42",
629		.pm = JC42_DEV_PM_OPS,
630		.of_match_table = of_match_ptr(jc42_of_ids),
631	},
632	.probe		= jc42_probe,
633	.remove		= jc42_remove,
634	.id_table	= jc42_id,
635	.detect		= jc42_detect,
636	.address_list	= normal_i2c,
637};
638
639module_i2c_driver(jc42_driver);
640
641MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
642MODULE_DESCRIPTION("JC42 driver");
643MODULE_LICENSE("GPL");