1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LM73 Sensor driver
4 * Based on LM75
5 *
6 * Copyright (C) 2007, CenoSYS (www.cenosys.com).
7 * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
8 *
9 * Guillaume Ligneul <guillaume.ligneul@gmail.com>
10 * Adrien Demarez <adrien.demarez@bolloretelecom.eu>
11 * Jeremy Laine <jeremy.laine@bolloretelecom.eu>
12 * Chris Verges <kg4ysn@gmail.com>
13 */
14
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/i2c.h>
18#include <linux/hwmon.h>
19#include <linux/hwmon-sysfs.h>
20#include <linux/err.h>
21
22
23/* Addresses scanned */
24static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
25					0x4d, 0x4e, I2C_CLIENT_END };
26
27/* LM73 registers */
28#define LM73_REG_INPUT		0x00
29#define LM73_REG_CONF		0x01
30#define LM73_REG_MAX		0x02
31#define LM73_REG_MIN		0x03
32#define LM73_REG_CTRL		0x04
33#define LM73_REG_ID		0x07
34
35#define LM73_ID			0x9001	/* 0x0190, byte-swapped */
36#define DRVNAME			"lm73"
37#define LM73_TEMP_MIN		(-256000 / 250)
38#define LM73_TEMP_MAX		(255750 / 250)
39
40#define LM73_CTRL_RES_SHIFT	5
41#define LM73_CTRL_RES_MASK	(BIT(5) | BIT(6))
42#define LM73_CTRL_TO_MASK	BIT(7)
43
44#define LM73_CTRL_HI_SHIFT	2
45#define LM73_CTRL_LO_SHIFT	1
46
47static const unsigned short lm73_convrates[] = {
48	14,	/* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */
49	28,	/* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */
50	56,	/* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */
51	112,	/* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */
52};
53
54struct lm73_data {
55	struct i2c_client *client;
56	struct mutex lock;
57	u8 ctrl;			/* control register value */
58};
59
60/*-----------------------------------------------------------------------*/
61
62static ssize_t temp_store(struct device *dev, struct device_attribute *da,
63			  const char *buf, size_t count)
64{
65	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
66	struct lm73_data *data = dev_get_drvdata(dev);
67	long temp;
68	short value;
69	s32 err;
70
71	int status = kstrtol(buf, 10, &temp);
72	if (status < 0)
73		return status;
74
75	/* Write value */
76	value = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5;
77	err = i2c_smbus_write_word_swapped(data->client, attr->index, value);
78	return (err < 0) ? err : count;
79}
80
81static ssize_t temp_show(struct device *dev, struct device_attribute *da,
82			 char *buf)
83{
84	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
85	struct lm73_data *data = dev_get_drvdata(dev);
86	int temp;
87
88	s32 err = i2c_smbus_read_word_swapped(data->client, attr->index);
89	if (err < 0)
90		return err;
91
92	/* use integer division instead of equivalent right shift to
93	   guarantee arithmetic shift and preserve the sign */
94	temp = (((s16) err) * 250) / 32;
95	return sysfs_emit(buf, "%d\n", temp);
96}
97
98static ssize_t convrate_store(struct device *dev, struct device_attribute *da,
99			      const char *buf, size_t count)
100{
101	struct lm73_data *data = dev_get_drvdata(dev);
102	unsigned long convrate;
103	s32 err;
104	int res = 0;
105
106	err = kstrtoul(buf, 10, &convrate);
107	if (err < 0)
108		return err;
109
110	/*
111	 * Convert the desired conversion rate into register bits.
112	 * res is already initialized, and everything past the second-to-last
113	 * value in the array is treated as belonging to the last value
114	 * in the array.
115	 */
116	while (res < (ARRAY_SIZE(lm73_convrates) - 1) &&
117			convrate > lm73_convrates[res])
118		res++;
119
120	mutex_lock(&data->lock);
121	data->ctrl &= LM73_CTRL_TO_MASK;
122	data->ctrl |= res << LM73_CTRL_RES_SHIFT;
123	err = i2c_smbus_write_byte_data(data->client, LM73_REG_CTRL,
124					data->ctrl);
125	mutex_unlock(&data->lock);
126
127	if (err < 0)
128		return err;
129
130	return count;
131}
132
133static ssize_t convrate_show(struct device *dev, struct device_attribute *da,
134			     char *buf)
135{
136	struct lm73_data *data = dev_get_drvdata(dev);
137	int res;
138
139	res = (data->ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT;
140	return sysfs_emit(buf, "%hu\n", lm73_convrates[res]);
141}
142
143static ssize_t maxmin_alarm_show(struct device *dev,
144				 struct device_attribute *da, char *buf)
145{
146	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
147	struct lm73_data *data = dev_get_drvdata(dev);
148	s32 ctrl;
149
150	mutex_lock(&data->lock);
151	ctrl = i2c_smbus_read_byte_data(data->client, LM73_REG_CTRL);
152	if (ctrl < 0)
153		goto abort;
154	data->ctrl = ctrl;
155	mutex_unlock(&data->lock);
156
157	return sysfs_emit(buf, "%d\n", (ctrl >> attr->index) & 1);
158
159abort:
160	mutex_unlock(&data->lock);
161	return ctrl;
162}
163
164/*-----------------------------------------------------------------------*/
165
166/* sysfs attributes for hwmon */
167
168static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, LM73_REG_MAX);
169static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, LM73_REG_MIN);
170static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, LM73_REG_INPUT);
171static SENSOR_DEVICE_ATTR_RW(update_interval, convrate, 0);
172static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, maxmin_alarm,
173			     LM73_CTRL_HI_SHIFT);
174static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, maxmin_alarm,
175			     LM73_CTRL_LO_SHIFT);
176
177static struct attribute *lm73_attrs[] = {
178	&sensor_dev_attr_temp1_input.dev_attr.attr,
179	&sensor_dev_attr_temp1_max.dev_attr.attr,
180	&sensor_dev_attr_temp1_min.dev_attr.attr,
181	&sensor_dev_attr_update_interval.dev_attr.attr,
182	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
183	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
184	NULL
185};
186ATTRIBUTE_GROUPS(lm73);
187
188/*-----------------------------------------------------------------------*/
189
190/* device probe and removal */
191
192static int
193lm73_probe(struct i2c_client *client)
194{
195	struct device *dev = &client->dev;
196	struct device *hwmon_dev;
197	struct lm73_data *data;
198	int ctrl;
199
200	data = devm_kzalloc(dev, sizeof(struct lm73_data), GFP_KERNEL);
201	if (!data)
202		return -ENOMEM;
203
204	data->client = client;
205	mutex_init(&data->lock);
206
207	ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL);
208	if (ctrl < 0)
209		return ctrl;
210	data->ctrl = ctrl;
211
212	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
213							   data, lm73_groups);
214	if (IS_ERR(hwmon_dev))
215		return PTR_ERR(hwmon_dev);
216
217	dev_info(dev, "sensor '%s'\n", client->name);
218
219	return 0;
220}
221
222static const struct i2c_device_id lm73_ids[] = {
223	{ "lm73" },
224	{ /* LIST END */ }
225};
226MODULE_DEVICE_TABLE(i2c, lm73_ids);
227
228/* Return 0 if detection is successful, -ENODEV otherwise */
229static int lm73_detect(struct i2c_client *new_client,
230			struct i2c_board_info *info)
231{
232	struct i2c_adapter *adapter = new_client->adapter;
233	int id, ctrl, conf;
234
235	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
236					I2C_FUNC_SMBUS_WORD_DATA))
237		return -ENODEV;
238
239	/*
240	 * Do as much detection as possible with byte reads first, as word
241	 * reads can confuse other devices.
242	 */
243	ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
244	if (ctrl < 0 || (ctrl & 0x10))
245		return -ENODEV;
246
247	conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF);
248	if (conf < 0 || (conf & 0x0c))
249		return -ENODEV;
250
251	id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID);
252	if (id < 0 || id != (LM73_ID & 0xff))
253		return -ENODEV;
254
255	/* Check device ID */
256	id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
257	if (id < 0 || id != LM73_ID)
258		return -ENODEV;
259
260	strscpy(info->type, "lm73", I2C_NAME_SIZE);
261
262	return 0;
263}
264
265static const struct of_device_id lm73_of_match[] = {
266	{
267		.compatible = "ti,lm73",
268	},
269	{ },
270};
271
272MODULE_DEVICE_TABLE(of, lm73_of_match);
273
274static struct i2c_driver lm73_driver = {
275	.class		= I2C_CLASS_HWMON,
276	.driver = {
277		.name	= "lm73",
278		.of_match_table = lm73_of_match,
279	},
280	.probe		= lm73_probe,
281	.id_table	= lm73_ids,
282	.detect		= lm73_detect,
283	.address_list	= normal_i2c,
284};
285
286module_i2c_driver(lm73_driver);
287
288MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
289MODULE_DESCRIPTION("LM73 driver");
290MODULE_LICENSE("GPL");
291