lm95241.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
  4 *
  5 * The LM95241 is a sensor chip made by National Semiconductors.
  6 * It reports up to three temperatures (its own plus up to two external ones).
  7 * Complete datasheet can be obtained from National's website at:
  8 *   http://www.national.com/ds.cgi/LM/LM95241.pdf
  9 */
 10
 11#include <linux/bitops.h>
 12#include <linux/err.h>
 13#include <linux/i2c.h>
 14#include <linux/init.h>
 15#include <linux/jiffies.h>
 16#include <linux/hwmon.h>
 17#include <linux/module.h>
 18#include <linux/slab.h>
 19
 20#define DEVNAME "lm95241"
 21
 22static const unsigned short normal_i2c[] = {
 23	0x19, 0x2a, 0x2b, I2C_CLIENT_END };
 24
 25/* LM95241 registers */
 26#define LM95241_REG_R_MAN_ID		0xFE
 27#define LM95241_REG_R_CHIP_ID		0xFF
 28#define LM95241_REG_R_STATUS		0x02
 29#define LM95241_REG_RW_CONFIG		0x03
 30#define LM95241_REG_RW_REM_FILTER	0x06
 31#define LM95241_REG_RW_TRUTHERM		0x07
 32#define LM95241_REG_W_ONE_SHOT		0x0F
 33#define LM95241_REG_R_LOCAL_TEMPH	0x10
 34#define LM95241_REG_R_REMOTE1_TEMPH	0x11
 35#define LM95241_REG_R_REMOTE2_TEMPH	0x12
 36#define LM95241_REG_R_LOCAL_TEMPL	0x20
 37#define LM95241_REG_R_REMOTE1_TEMPL	0x21
 38#define LM95241_REG_R_REMOTE2_TEMPL	0x22
 39#define LM95241_REG_RW_REMOTE_MODEL	0x30
 40
 41/* LM95241 specific bitfields */
 42#define CFG_STOP	BIT(6)
 43#define CFG_CR0076	0x00
 44#define CFG_CR0182	BIT(4)
 45#define CFG_CR1000	BIT(5)
 46#define CFG_CR2700	(BIT(4) | BIT(5))
 47#define CFG_CRMASK	(BIT(4) | BIT(5))
 48#define R1MS_MASK	BIT(0)
 49#define R2MS_MASK	BIT(2)
 50#define R1DF_MASK	BIT(1)
 51#define R2DF_MASK	BIT(2)
 52#define R1FE_MASK	BIT(0)
 53#define R2FE_MASK	BIT(2)
 54#define R1DM		BIT(0)
 55#define R2DM		BIT(1)
 56#define TT1_SHIFT	0
 57#define TT2_SHIFT	4
 58#define TT_OFF		0
 59#define TT_ON		1
 60#define TT_MASK		7
 61#define NATSEMI_MAN_ID	0x01
 62#define LM95231_CHIP_ID	0xA1
 63#define LM95241_CHIP_ID	0xA4
 64
 65static const u8 lm95241_reg_address[] = {
 66	LM95241_REG_R_LOCAL_TEMPH,
 67	LM95241_REG_R_LOCAL_TEMPL,
 68	LM95241_REG_R_REMOTE1_TEMPH,
 69	LM95241_REG_R_REMOTE1_TEMPL,
 70	LM95241_REG_R_REMOTE2_TEMPH,
 71	LM95241_REG_R_REMOTE2_TEMPL
 72};
 73
 74/* Client data (each client gets its own) */
 75struct lm95241_data {
 76	struct i2c_client *client;
 77	unsigned long last_updated;	/* in jiffies */
 78	unsigned long interval;		/* in milli-seconds */
 79	bool valid;		/* false until following fields are valid */
 80	/* registers values */
 81	u8 temp[ARRAY_SIZE(lm95241_reg_address)];
 82	u8 status, config, model, trutherm;
 83};
 84
 85/* Conversions */
 86static int temp_from_reg_signed(u8 val_h, u8 val_l)
 87{
 88	s16 val_hl = (val_h << 8) | val_l;
 89	return val_hl * 1000 / 256;
 90}
 91
 92static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 93{
 94	u16 val_hl = (val_h << 8) | val_l;
 95	return val_hl * 1000 / 256;
 96}
 97
 98static struct lm95241_data *lm95241_update_device(struct device *dev)
 99{
100	struct lm95241_data *data = dev_get_drvdata(dev);
101	struct i2c_client *client = data->client;
102
103	if (time_after(jiffies, data->last_updated
104		       + msecs_to_jiffies(data->interval)) ||
105	    !data->valid) {
106		int i;
107
108		dev_dbg(dev, "Updating lm95241 data.\n");
109		for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
110			data->temp[i]
111			  = i2c_smbus_read_byte_data(client,
112						     lm95241_reg_address[i]);
113
114		data->status = i2c_smbus_read_byte_data(client,
115							LM95241_REG_R_STATUS);
116		data->last_updated = jiffies;
117		data->valid = true;
118	}
119	return data;
120}
121
122static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
123			     long *val)
124{
125	struct lm95241_data *data = dev_get_drvdata(dev);
126
127	switch (attr) {
128	case hwmon_chip_update_interval:
129		*val = data->interval;
130		return 0;
131	default:
132		return -EOPNOTSUPP;
133	}
134}
135
136static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
137			     long *val)
138{
139	struct lm95241_data *data = lm95241_update_device(dev);
140
141	switch (attr) {
142	case hwmon_temp_input:
143		if (!channel || (data->config & BIT(channel - 1)))
144			*val = temp_from_reg_signed(data->temp[channel * 2],
145						data->temp[channel * 2 + 1]);
146		else
147			*val = temp_from_reg_unsigned(data->temp[channel * 2],
148						data->temp[channel * 2 + 1]);
149		return 0;
150	case hwmon_temp_min:
151		if (channel == 1)
152			*val = (data->config & R1DF_MASK) ? -128000 : 0;
153		else
154			*val = (data->config & R2DF_MASK) ? -128000 : 0;
155		return 0;
156	case hwmon_temp_max:
157		if (channel == 1)
158			*val = (data->config & R1DF_MASK) ? 127875 : 255875;
159		else
160			*val = (data->config & R2DF_MASK) ? 127875 : 255875;
161		return 0;
162	case hwmon_temp_type:
163		if (channel == 1)
164			*val = (data->model & R1MS_MASK) ? 1 : 2;
165		else
166			*val = (data->model & R2MS_MASK) ? 1 : 2;
167		return 0;
168	case hwmon_temp_fault:
169		if (channel == 1)
170			*val = !!(data->status & R1DM);
171		else
172			*val = !!(data->status & R2DM);
173		return 0;
174	default:
175		return -EOPNOTSUPP;
176	}
177}
178
179static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
180			u32 attr, int channel, long *val)
181{
182	switch (type) {
183	case hwmon_chip:
184		return lm95241_read_chip(dev, attr, channel, val);
185	case hwmon_temp:
186		return lm95241_read_temp(dev, attr, channel, val);
187	default:
188		return -EOPNOTSUPP;
189	}
190}
191
192static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
193			      long val)
194{
195	struct lm95241_data *data = dev_get_drvdata(dev);
196	int convrate;
197	u8 config;
198	int ret;
199
200	switch (attr) {
201	case hwmon_chip_update_interval:
202		config = data->config & ~CFG_CRMASK;
203		if (val < 130) {
204			convrate = 76;
205			config |= CFG_CR0076;
206		} else if (val < 590) {
207			convrate = 182;
208			config |= CFG_CR0182;
209		} else if (val < 1850) {
210			convrate = 1000;
211			config |= CFG_CR1000;
212		} else {
213			convrate = 2700;
214			config |= CFG_CR2700;
215		}
216		data->interval = convrate;
217		data->config = config;
218		ret = i2c_smbus_write_byte_data(data->client,
219						LM95241_REG_RW_CONFIG, config);
220		break;
221	default:
222		ret = -EOPNOTSUPP;
223		break;
224	}
225	return ret;
226}
227
228static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
229			      long val)
230{
231	struct lm95241_data *data = dev_get_drvdata(dev);
232	struct i2c_client *client = data->client;
233	int ret;
234
235	switch (attr) {
236	case hwmon_temp_min:
237		if (channel == 1) {
238			if (val < 0)
239				data->config |= R1DF_MASK;
240			else
241				data->config &= ~R1DF_MASK;
242		} else {
243			if (val < 0)
244				data->config |= R2DF_MASK;
245			else
246				data->config &= ~R2DF_MASK;
247		}
248		data->valid = false;
249		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
250						data->config);
251		break;
252	case hwmon_temp_max:
253		if (channel == 1) {
254			if (val <= 127875)
255				data->config |= R1DF_MASK;
256			else
257				data->config &= ~R1DF_MASK;
258		} else {
259			if (val <= 127875)
260				data->config |= R2DF_MASK;
261			else
262				data->config &= ~R2DF_MASK;
263		}
264		data->valid = false;
265		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
266						data->config);
267		break;
268	case hwmon_temp_type:
269		if (val != 1 && val != 2) {
270			ret = -EINVAL;
271			break;
272		}
273		if (channel == 1) {
274			data->trutherm &= ~(TT_MASK << TT1_SHIFT);
275			if (val == 1) {
276				data->model |= R1MS_MASK;
277				data->trutherm |= (TT_ON << TT1_SHIFT);
278			} else {
279				data->model &= ~R1MS_MASK;
280				data->trutherm |= (TT_OFF << TT1_SHIFT);
281			}
282		} else {
283			data->trutherm &= ~(TT_MASK << TT2_SHIFT);
284			if (val == 1) {
285				data->model |= R2MS_MASK;
286				data->trutherm |= (TT_ON << TT2_SHIFT);
287			} else {
288				data->model &= ~R2MS_MASK;
289				data->trutherm |= (TT_OFF << TT2_SHIFT);
290			}
291		}
292		ret = i2c_smbus_write_byte_data(client,
293						LM95241_REG_RW_REMOTE_MODEL,
294						data->model);
295		if (ret < 0)
296			break;
297		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
298						data->trutherm);
299		break;
300	default:
301		ret = -EOPNOTSUPP;
302		break;
303	}
304	return ret;
305}
306
307static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
308			 u32 attr, int channel, long val)
309{
310	switch (type) {
311	case hwmon_chip:
312		return lm95241_write_chip(dev, attr, channel, val);
313	case hwmon_temp:
314		return lm95241_write_temp(dev, attr, channel, val);
315	default:
316		return -EOPNOTSUPP;
317	}
318}
319
320static umode_t lm95241_is_visible(const void *data,
321				  enum hwmon_sensor_types type,
322				  u32 attr, int channel)
323{
324	switch (type) {
325	case hwmon_chip:
326		switch (attr) {
327		case hwmon_chip_update_interval:
328			return 0644;
329		}
330		break;
331	case hwmon_temp:
332		switch (attr) {
333		case hwmon_temp_input:
334			return 0444;
335		case hwmon_temp_fault:
336			return 0444;
337		case hwmon_temp_min:
338		case hwmon_temp_max:
339		case hwmon_temp_type:
340			return 0644;
341		}
342		break;
343	default:
344		break;
345	}
346	return 0;
347}
348
349/* Return 0 if detection is successful, -ENODEV otherwise */
350static int lm95241_detect(struct i2c_client *new_client,
351			  struct i2c_board_info *info)
352{
353	struct i2c_adapter *adapter = new_client->adapter;
354	const char *name;
355	int mfg_id, chip_id;
356
357	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
358		return -ENODEV;
359
360	mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
361	if (mfg_id != NATSEMI_MAN_ID)
362		return -ENODEV;
363
364	chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
365	switch (chip_id) {
366	case LM95231_CHIP_ID:
367		name = "lm95231";
368		break;
369	case LM95241_CHIP_ID:
370		name = "lm95241";
371		break;
372	default:
373		return -ENODEV;
374	}
375
376	/* Fill the i2c board info */
377	strscpy(info->type, name, I2C_NAME_SIZE);
378	return 0;
379}
380
381static void lm95241_init_client(struct i2c_client *client,
382				struct lm95241_data *data)
383{
384	data->interval = 1000;
385	data->config = CFG_CR1000;
386	data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
387
388	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
389	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
390				  R1FE_MASK | R2FE_MASK);
391	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
392				  data->trutherm);
393	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
394				  data->model);
395}
396
397static const struct hwmon_channel_info * const lm95241_info[] = {
398	HWMON_CHANNEL_INFO(chip,
399			   HWMON_C_UPDATE_INTERVAL),
400	HWMON_CHANNEL_INFO(temp,
401			   HWMON_T_INPUT,
402			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
403			   HWMON_T_TYPE | HWMON_T_FAULT,
404			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
405			   HWMON_T_TYPE | HWMON_T_FAULT),
406	NULL
407};
408
409static const struct hwmon_ops lm95241_hwmon_ops = {
410	.is_visible = lm95241_is_visible,
411	.read = lm95241_read,
412	.write = lm95241_write,
413};
414
415static const struct hwmon_chip_info lm95241_chip_info = {
416	.ops = &lm95241_hwmon_ops,
417	.info = lm95241_info,
418};
419
420static int lm95241_probe(struct i2c_client *client)
421{
422	struct device *dev = &client->dev;
423	struct lm95241_data *data;
424	struct device *hwmon_dev;
425
426	data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
427	if (!data)
428		return -ENOMEM;
429
430	data->client = client;
431
432	/* Initialize the LM95241 chip */
433	lm95241_init_client(client, data);
434
435	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
436							   data,
437							   &lm95241_chip_info,
438							   NULL);
439	return PTR_ERR_OR_ZERO(hwmon_dev);
440}
441
442/* Driver data (common to all clients) */
443static const struct i2c_device_id lm95241_id[] = {
444	{ "lm95231" },
445	{ "lm95241" },
446	{ }
447};
448MODULE_DEVICE_TABLE(i2c, lm95241_id);
449
450static struct i2c_driver lm95241_driver = {
451	.class		= I2C_CLASS_HWMON,
452	.driver = {
453		.name	= DEVNAME,
454	},
455	.probe		= lm95241_probe,
456	.id_table	= lm95241_id,
457	.detect		= lm95241_detect,
458	.address_list	= normal_i2c,
459};
460
461module_i2c_driver(lm95241_driver);
462
463MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
464MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
465MODULE_LICENSE("GPL");