xref: /kernel/linux/linux-5.10/drivers/hwmon/tmp421.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* tmp421.c
3 *
4 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
5 * Preliminary support by:
6 * Melvin Rook, Raymond Ng
7 */
8
9/*
10 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
11 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
12 */
13
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/hwmon-sysfs.h>
21#include <linux/err.h>
22#include <linux/mutex.h>
23#include <linux/of_device.h>
24#include <linux/sysfs.h>
25
26/* Addresses to scan */
27static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
28					     I2C_CLIENT_END };
29
30enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
31
32/* The TMP421 registers */
33#define TMP421_STATUS_REG			0x08
34#define TMP421_CONFIG_REG_1			0x09
35#define TMP421_CONVERSION_RATE_REG		0x0B
36#define TMP421_MANUFACTURER_ID_REG		0xFE
37#define TMP421_DEVICE_ID_REG			0xFF
38
39static const u8 TMP421_TEMP_MSB[4]		= { 0x00, 0x01, 0x02, 0x03 };
40static const u8 TMP421_TEMP_LSB[4]		= { 0x10, 0x11, 0x12, 0x13 };
41
42/* Flags */
43#define TMP421_CONFIG_SHUTDOWN			0x40
44#define TMP421_CONFIG_RANGE			0x04
45
46/* Manufacturer / Device ID's */
47#define TMP421_MANUFACTURER_ID			0x55
48#define TMP421_DEVICE_ID			0x21
49#define TMP422_DEVICE_ID			0x22
50#define TMP423_DEVICE_ID			0x23
51#define TMP441_DEVICE_ID			0x41
52#define TMP442_DEVICE_ID			0x42
53
54static const struct i2c_device_id tmp421_id[] = {
55	{ "tmp421", 2 },
56	{ "tmp422", 3 },
57	{ "tmp423", 4 },
58	{ "tmp441", 2 },
59	{ "tmp442", 3 },
60	{ }
61};
62MODULE_DEVICE_TABLE(i2c, tmp421_id);
63
64static const struct of_device_id __maybe_unused tmp421_of_match[] = {
65	{
66		.compatible = "ti,tmp421",
67		.data = (void *)2
68	},
69	{
70		.compatible = "ti,tmp422",
71		.data = (void *)3
72	},
73	{
74		.compatible = "ti,tmp423",
75		.data = (void *)4
76	},
77	{
78		.compatible = "ti,tmp441",
79		.data = (void *)2
80	},
81	{
82		.compatible = "ti,tmp442",
83		.data = (void *)3
84	},
85	{ },
86};
87MODULE_DEVICE_TABLE(of, tmp421_of_match);
88
89struct tmp421_data {
90	struct i2c_client *client;
91	struct mutex update_lock;
92	u32 temp_config[5];
93	struct hwmon_channel_info temp_info;
94	const struct hwmon_channel_info *info[2];
95	struct hwmon_chip_info chip;
96	char valid;
97	unsigned long last_updated;
98	unsigned long channels;
99	u8 config;
100	s16 temp[4];
101};
102
103static int temp_from_raw(u16 reg, bool extended)
104{
105	/* Mask out status bits */
106	int temp = reg & ~0xf;
107
108	if (extended)
109		temp = temp - 64 * 256;
110	else
111		temp = (s16)temp;
112
113	return DIV_ROUND_CLOSEST(temp * 1000, 256);
114}
115
116static int tmp421_update_device(struct tmp421_data *data)
117{
118	struct i2c_client *client = data->client;
119	int ret = 0;
120	int i;
121
122	mutex_lock(&data->update_lock);
123
124	if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
125	    !data->valid) {
126		ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
127		if (ret < 0)
128			goto exit;
129		data->config = ret;
130
131		for (i = 0; i < data->channels; i++) {
132			ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
133			if (ret < 0)
134				goto exit;
135			data->temp[i] = ret << 8;
136
137			ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
138			if (ret < 0)
139				goto exit;
140			data->temp[i] |= ret;
141		}
142		data->last_updated = jiffies;
143		data->valid = 1;
144	}
145
146exit:
147	mutex_unlock(&data->update_lock);
148
149	if (ret < 0) {
150		data->valid = 0;
151		return ret;
152	}
153
154	return 0;
155}
156
157static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
158		       u32 attr, int channel, long *val)
159{
160	struct tmp421_data *tmp421 = dev_get_drvdata(dev);
161	int ret = 0;
162
163	ret = tmp421_update_device(tmp421);
164	if (ret)
165		return ret;
166
167	switch (attr) {
168	case hwmon_temp_input:
169		*val = temp_from_raw(tmp421->temp[channel],
170				     tmp421->config & TMP421_CONFIG_RANGE);
171		return 0;
172	case hwmon_temp_fault:
173		/*
174		 * Any of OPEN or /PVLD bits indicate a hardware mulfunction
175		 * and the conversion result may be incorrect
176		 */
177		*val = !!(tmp421->temp[channel] & 0x03);
178		return 0;
179	default:
180		return -EOPNOTSUPP;
181	}
182
183}
184
185static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
186				 u32 attr, int channel)
187{
188	switch (attr) {
189	case hwmon_temp_fault:
190	case hwmon_temp_input:
191		return 0444;
192	default:
193		return 0;
194	}
195}
196
197static int tmp421_init_client(struct i2c_client *client)
198{
199	int config, config_orig;
200
201	/* Set the conversion rate to 2 Hz */
202	i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
203
204	/* Start conversions (disable shutdown if necessary) */
205	config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
206	if (config < 0) {
207		dev_err(&client->dev,
208			"Could not read configuration register (%d)\n", config);
209		return config;
210	}
211
212	config_orig = config;
213	config &= ~TMP421_CONFIG_SHUTDOWN;
214
215	if (config != config_orig) {
216		dev_info(&client->dev, "Enable monitoring chip\n");
217		i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
218	}
219
220	return 0;
221}
222
223static int tmp421_detect(struct i2c_client *client,
224			 struct i2c_board_info *info)
225{
226	enum chips kind;
227	struct i2c_adapter *adapter = client->adapter;
228	static const char * const names[] = {
229		"TMP421", "TMP422", "TMP423",
230		"TMP441", "TMP442"
231	};
232	int addr = client->addr;
233	u8 reg;
234
235	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
236		return -ENODEV;
237
238	reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
239	if (reg != TMP421_MANUFACTURER_ID)
240		return -ENODEV;
241
242	reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
243	if (reg & 0xf8)
244		return -ENODEV;
245
246	reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
247	if (reg & 0x7f)
248		return -ENODEV;
249
250	reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
251	switch (reg) {
252	case TMP421_DEVICE_ID:
253		kind = tmp421;
254		break;
255	case TMP422_DEVICE_ID:
256		if (addr == 0x2a)
257			return -ENODEV;
258		kind = tmp422;
259		break;
260	case TMP423_DEVICE_ID:
261		if (addr != 0x4c && addr != 0x4d)
262			return -ENODEV;
263		kind = tmp423;
264		break;
265	case TMP441_DEVICE_ID:
266		kind = tmp441;
267		break;
268	case TMP442_DEVICE_ID:
269		if (addr != 0x4c && addr != 0x4d)
270			return -ENODEV;
271		kind = tmp442;
272		break;
273	default:
274		return -ENODEV;
275	}
276
277	strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
278	dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
279		 names[kind], client->addr);
280
281	return 0;
282}
283
284static const struct hwmon_ops tmp421_ops = {
285	.is_visible = tmp421_is_visible,
286	.read = tmp421_read,
287};
288
289static int tmp421_probe(struct i2c_client *client)
290{
291	struct device *dev = &client->dev;
292	struct device *hwmon_dev;
293	struct tmp421_data *data;
294	int i, err;
295
296	data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
297	if (!data)
298		return -ENOMEM;
299
300	mutex_init(&data->update_lock);
301	if (client->dev.of_node)
302		data->channels = (unsigned long)
303			of_device_get_match_data(&client->dev);
304	else
305		data->channels = i2c_match_id(tmp421_id, client)->driver_data;
306	data->client = client;
307
308	err = tmp421_init_client(client);
309	if (err)
310		return err;
311
312	for (i = 0; i < data->channels; i++)
313		data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
314
315	data->chip.ops = &tmp421_ops;
316	data->chip.info = data->info;
317
318	data->info[0] = &data->temp_info;
319
320	data->temp_info.type = hwmon_temp;
321	data->temp_info.config = data->temp_config;
322
323	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
324							 data,
325							 &data->chip,
326							 NULL);
327	return PTR_ERR_OR_ZERO(hwmon_dev);
328}
329
330static struct i2c_driver tmp421_driver = {
331	.class = I2C_CLASS_HWMON,
332	.driver = {
333		.name	= "tmp421",
334		.of_match_table = of_match_ptr(tmp421_of_match),
335	},
336	.probe_new = tmp421_probe,
337	.id_table = tmp421_id,
338	.detect = tmp421_detect,
339	.address_list = normal_i2c,
340};
341
342module_i2c_driver(tmp421_driver);
343
344MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
345MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
346MODULE_LICENSE("GPL");
347