1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* Texas Instruments TMP102 SMBus temperature sensor driver |
3 | * |
4 | * Copyright (C) 2010 Steven King <sfking@fdwdc.com> |
5 | */ |
6 | |
7 | #include <linux/delay.h> |
8 | #include <linux/module.h> |
9 | #include <linux/init.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/i2c.h> |
12 | #include <linux/hwmon.h> |
13 | #include <linux/hwmon-sysfs.h> |
14 | #include <linux/err.h> |
15 | #include <linux/mutex.h> |
16 | #include <linux/device.h> |
17 | #include <linux/jiffies.h> |
18 | #include <linux/regmap.h> |
19 | #include <linux/of.h> |
20 | |
21 | #define DRIVER_NAME "tmp102" |
22 | |
23 | #define TMP102_TEMP_REG 0x00 |
24 | #define TMP102_CONF_REG 0x01 |
25 | /* note: these bit definitions are byte swapped */ |
26 | #define TMP102_CONF_SD 0x0100 |
27 | #define TMP102_CONF_TM 0x0200 |
28 | #define TMP102_CONF_POL 0x0400 |
29 | #define TMP102_CONF_F0 0x0800 |
30 | #define TMP102_CONF_F1 0x1000 |
31 | #define TMP102_CONF_R0 0x2000 |
32 | #define TMP102_CONF_R1 0x4000 |
33 | #define TMP102_CONF_OS 0x8000 |
34 | #define TMP102_CONF_EM 0x0010 |
35 | #define TMP102_CONF_AL 0x0020 |
36 | #define TMP102_CONF_CR0 0x0040 |
37 | #define TMP102_CONF_CR1 0x0080 |
38 | #define TMP102_TLOW_REG 0x02 |
39 | #define TMP102_THIGH_REG 0x03 |
40 | |
41 | #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ |
42 | TMP102_CONF_POL | TMP102_CONF_F0 | \ |
43 | TMP102_CONF_F1 | TMP102_CONF_OS | \ |
44 | TMP102_CONF_EM | TMP102_CONF_AL | \ |
45 | TMP102_CONF_CR0 | TMP102_CONF_CR1) |
46 | |
47 | #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ |
48 | TMP102_CONF_CR0) |
49 | #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ |
50 | TMP102_CONF_CR1) |
51 | |
52 | #define CONVERSION_TIME_MS 35 /* in milli-seconds */ |
53 | |
54 | struct tmp102 { |
55 | struct regmap *regmap; |
56 | u16 config_orig; |
57 | unsigned long ready_time; |
58 | }; |
59 | |
60 | /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ |
61 | static inline int tmp102_reg_to_mC(s16 val) |
62 | { |
63 | return ((val & ~0x01) * 1000) / 128; |
64 | } |
65 | |
66 | /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ |
67 | static inline u16 tmp102_mC_to_reg(int val) |
68 | { |
69 | return (val * 128) / 1000; |
70 | } |
71 | |
72 | static int tmp102_read(struct device *dev, enum hwmon_sensor_types type, |
73 | u32 attr, int channel, long *temp) |
74 | { |
75 | struct tmp102 *tmp102 = dev_get_drvdata(dev); |
76 | unsigned int regval; |
77 | int err, reg; |
78 | |
79 | switch (attr) { |
80 | case hwmon_temp_input: |
81 | /* Is it too early to return a conversion ? */ |
82 | if (time_before(jiffies, tmp102->ready_time)) { |
83 | dev_dbg(dev, "%s: Conversion not ready yet..\n" , __func__); |
84 | return -EAGAIN; |
85 | } |
86 | reg = TMP102_TEMP_REG; |
87 | break; |
88 | case hwmon_temp_max_hyst: |
89 | reg = TMP102_TLOW_REG; |
90 | break; |
91 | case hwmon_temp_max: |
92 | reg = TMP102_THIGH_REG; |
93 | break; |
94 | default: |
95 | return -EOPNOTSUPP; |
96 | } |
97 | |
98 | err = regmap_read(map: tmp102->regmap, reg, val: ®val); |
99 | if (err < 0) |
100 | return err; |
101 | *temp = tmp102_reg_to_mC(val: regval); |
102 | |
103 | return 0; |
104 | } |
105 | |
106 | static int tmp102_write(struct device *dev, enum hwmon_sensor_types type, |
107 | u32 attr, int channel, long temp) |
108 | { |
109 | struct tmp102 *tmp102 = dev_get_drvdata(dev); |
110 | int reg; |
111 | |
112 | switch (attr) { |
113 | case hwmon_temp_max_hyst: |
114 | reg = TMP102_TLOW_REG; |
115 | break; |
116 | case hwmon_temp_max: |
117 | reg = TMP102_THIGH_REG; |
118 | break; |
119 | default: |
120 | return -EOPNOTSUPP; |
121 | } |
122 | |
123 | temp = clamp_val(temp, -256000, 255000); |
124 | return regmap_write(map: tmp102->regmap, reg, val: tmp102_mC_to_reg(val: temp)); |
125 | } |
126 | |
127 | static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type, |
128 | u32 attr, int channel) |
129 | { |
130 | if (type != hwmon_temp) |
131 | return 0; |
132 | |
133 | switch (attr) { |
134 | case hwmon_temp_input: |
135 | return 0444; |
136 | case hwmon_temp_max_hyst: |
137 | case hwmon_temp_max: |
138 | return 0644; |
139 | default: |
140 | return 0; |
141 | } |
142 | } |
143 | |
144 | static const struct hwmon_channel_info * const tmp102_info[] = { |
145 | HWMON_CHANNEL_INFO(chip, |
146 | HWMON_C_REGISTER_TZ), |
147 | HWMON_CHANNEL_INFO(temp, |
148 | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST), |
149 | NULL |
150 | }; |
151 | |
152 | static const struct hwmon_ops tmp102_hwmon_ops = { |
153 | .is_visible = tmp102_is_visible, |
154 | .read = tmp102_read, |
155 | .write = tmp102_write, |
156 | }; |
157 | |
158 | static const struct hwmon_chip_info tmp102_chip_info = { |
159 | .ops = &tmp102_hwmon_ops, |
160 | .info = tmp102_info, |
161 | }; |
162 | |
163 | static void tmp102_restore_config(void *data) |
164 | { |
165 | struct tmp102 *tmp102 = data; |
166 | |
167 | regmap_write(map: tmp102->regmap, TMP102_CONF_REG, val: tmp102->config_orig); |
168 | } |
169 | |
170 | static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) |
171 | { |
172 | return reg != TMP102_TEMP_REG; |
173 | } |
174 | |
175 | static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) |
176 | { |
177 | return reg == TMP102_TEMP_REG; |
178 | } |
179 | |
180 | static const struct regmap_config tmp102_regmap_config = { |
181 | .reg_bits = 8, |
182 | .val_bits = 16, |
183 | .max_register = TMP102_THIGH_REG, |
184 | .writeable_reg = tmp102_is_writeable_reg, |
185 | .volatile_reg = tmp102_is_volatile_reg, |
186 | .val_format_endian = REGMAP_ENDIAN_BIG, |
187 | .cache_type = REGCACHE_MAPLE, |
188 | .use_single_read = true, |
189 | .use_single_write = true, |
190 | }; |
191 | |
192 | static int tmp102_probe(struct i2c_client *client) |
193 | { |
194 | struct device *dev = &client->dev; |
195 | struct device *hwmon_dev; |
196 | struct tmp102 *tmp102; |
197 | unsigned int regval; |
198 | int err; |
199 | |
200 | if (!i2c_check_functionality(adap: client->adapter, |
201 | I2C_FUNC_SMBUS_WORD_DATA)) { |
202 | dev_err(dev, |
203 | "adapter doesn't support SMBus word transactions\n" ); |
204 | return -ENODEV; |
205 | } |
206 | |
207 | tmp102 = devm_kzalloc(dev, size: sizeof(*tmp102), GFP_KERNEL); |
208 | if (!tmp102) |
209 | return -ENOMEM; |
210 | |
211 | i2c_set_clientdata(client, data: tmp102); |
212 | |
213 | tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); |
214 | if (IS_ERR(ptr: tmp102->regmap)) |
215 | return PTR_ERR(ptr: tmp102->regmap); |
216 | |
217 | err = regmap_read(map: tmp102->regmap, TMP102_CONF_REG, val: ®val); |
218 | if (err < 0) { |
219 | dev_err(dev, "error reading config register\n" ); |
220 | return err; |
221 | } |
222 | |
223 | if ((regval & ~TMP102_CONFREG_MASK) != |
224 | (TMP102_CONF_R0 | TMP102_CONF_R1)) { |
225 | dev_err(dev, "unexpected config register value\n" ); |
226 | return -ENODEV; |
227 | } |
228 | |
229 | tmp102->config_orig = regval; |
230 | |
231 | err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); |
232 | if (err) |
233 | return err; |
234 | |
235 | regval &= ~TMP102_CONFIG_CLEAR; |
236 | regval |= TMP102_CONFIG_SET; |
237 | |
238 | err = regmap_write(map: tmp102->regmap, TMP102_CONF_REG, val: regval); |
239 | if (err < 0) { |
240 | dev_err(dev, "error writing config register\n" ); |
241 | return err; |
242 | } |
243 | |
244 | /* |
245 | * Mark that we are not ready with data until the first |
246 | * conversion is complete |
247 | */ |
248 | tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); |
249 | |
250 | hwmon_dev = devm_hwmon_device_register_with_info(dev, name: client->name, |
251 | drvdata: tmp102, |
252 | info: &tmp102_chip_info, |
253 | NULL); |
254 | if (IS_ERR(ptr: hwmon_dev)) { |
255 | dev_dbg(dev, "unable to register hwmon device\n" ); |
256 | return PTR_ERR(ptr: hwmon_dev); |
257 | } |
258 | dev_info(dev, "initialized\n" ); |
259 | |
260 | return 0; |
261 | } |
262 | |
263 | static int tmp102_suspend(struct device *dev) |
264 | { |
265 | struct i2c_client *client = to_i2c_client(dev); |
266 | struct tmp102 *tmp102 = i2c_get_clientdata(client); |
267 | |
268 | return regmap_update_bits(map: tmp102->regmap, TMP102_CONF_REG, |
269 | TMP102_CONF_SD, TMP102_CONF_SD); |
270 | } |
271 | |
272 | static int tmp102_resume(struct device *dev) |
273 | { |
274 | struct i2c_client *client = to_i2c_client(dev); |
275 | struct tmp102 *tmp102 = i2c_get_clientdata(client); |
276 | int err; |
277 | |
278 | err = regmap_update_bits(map: tmp102->regmap, TMP102_CONF_REG, |
279 | TMP102_CONF_SD, val: 0); |
280 | |
281 | tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); |
282 | |
283 | return err; |
284 | } |
285 | |
286 | static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); |
287 | |
288 | static const struct i2c_device_id tmp102_id[] = { |
289 | { "tmp102" , 0 }, |
290 | { } |
291 | }; |
292 | MODULE_DEVICE_TABLE(i2c, tmp102_id); |
293 | |
294 | static const struct of_device_id __maybe_unused tmp102_of_match[] = { |
295 | { .compatible = "ti,tmp102" }, |
296 | { }, |
297 | }; |
298 | MODULE_DEVICE_TABLE(of, tmp102_of_match); |
299 | |
300 | static struct i2c_driver tmp102_driver = { |
301 | .driver.name = DRIVER_NAME, |
302 | .driver.of_match_table = of_match_ptr(tmp102_of_match), |
303 | .driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops), |
304 | .probe = tmp102_probe, |
305 | .id_table = tmp102_id, |
306 | }; |
307 | |
308 | module_i2c_driver(tmp102_driver); |
309 | |
310 | MODULE_AUTHOR("Steven King <sfking@fdwdc.com>" ); |
311 | MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver" ); |
312 | MODULE_LICENSE("GPL" ); |
313 | |