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6e34b187 IS |
1 | /* |
2 | * Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller | |
3 | * | |
4 | * Copyright (C) 2008 Ira W. Snyder <iws@ovro.caltech.edu> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; version 2 of the License. | |
9 | * | |
10 | * This driver is based on the ds1621 and ina209 drivers. | |
11 | * | |
12 | * Datasheet: | |
13 | * http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1140,P19392,D13517 | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/i2c.h> | |
22 | #include <linux/hwmon.h> | |
23 | #include <linux/hwmon-sysfs.h> | |
24 | ||
6e34b187 IS |
25 | /* Here are names of the chip's registers (a.k.a. commands) */ |
26 | enum ltc4245_cmd { | |
27 | LTC4245_STATUS = 0x00, /* readonly */ | |
28 | LTC4245_ALERT = 0x01, | |
29 | LTC4245_CONTROL = 0x02, | |
30 | LTC4245_ON = 0x03, | |
31 | LTC4245_FAULT1 = 0x04, | |
32 | LTC4245_FAULT2 = 0x05, | |
33 | LTC4245_GPIO = 0x06, | |
34 | LTC4245_ADCADR = 0x07, | |
35 | ||
36 | LTC4245_12VIN = 0x10, | |
37 | LTC4245_12VSENSE = 0x11, | |
38 | LTC4245_12VOUT = 0x12, | |
39 | LTC4245_5VIN = 0x13, | |
40 | LTC4245_5VSENSE = 0x14, | |
41 | LTC4245_5VOUT = 0x15, | |
42 | LTC4245_3VIN = 0x16, | |
43 | LTC4245_3VSENSE = 0x17, | |
44 | LTC4245_3VOUT = 0x18, | |
45 | LTC4245_VEEIN = 0x19, | |
46 | LTC4245_VEESENSE = 0x1a, | |
47 | LTC4245_VEEOUT = 0x1b, | |
df16dd53 | 48 | LTC4245_GPIOADC = 0x1c, |
6e34b187 IS |
49 | }; |
50 | ||
51 | struct ltc4245_data { | |
52 | struct device *hwmon_dev; | |
53 | ||
54 | struct mutex update_lock; | |
55 | bool valid; | |
56 | unsigned long last_updated; /* in jiffies */ | |
57 | ||
58 | /* Control registers */ | |
59 | u8 cregs[0x08]; | |
60 | ||
61 | /* Voltage registers */ | |
df16dd53 | 62 | u8 vregs[0x0d]; |
6e34b187 IS |
63 | }; |
64 | ||
65 | static struct ltc4245_data *ltc4245_update_device(struct device *dev) | |
66 | { | |
67 | struct i2c_client *client = to_i2c_client(dev); | |
68 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
69 | s32 val; | |
70 | int i; | |
71 | ||
72 | mutex_lock(&data->update_lock); | |
73 | ||
74 | if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { | |
75 | ||
76 | dev_dbg(&client->dev, "Starting ltc4245 update\n"); | |
77 | ||
78 | /* Read control registers -- 0x00 to 0x07 */ | |
79 | for (i = 0; i < ARRAY_SIZE(data->cregs); i++) { | |
80 | val = i2c_smbus_read_byte_data(client, i); | |
81 | if (unlikely(val < 0)) | |
82 | data->cregs[i] = 0; | |
83 | else | |
84 | data->cregs[i] = val; | |
85 | } | |
86 | ||
df16dd53 | 87 | /* Read voltage registers -- 0x10 to 0x1c */ |
6e34b187 IS |
88 | for (i = 0; i < ARRAY_SIZE(data->vregs); i++) { |
89 | val = i2c_smbus_read_byte_data(client, i+0x10); | |
90 | if (unlikely(val < 0)) | |
91 | data->vregs[i] = 0; | |
92 | else | |
93 | data->vregs[i] = val; | |
94 | } | |
95 | ||
96 | data->last_updated = jiffies; | |
97 | data->valid = 1; | |
98 | } | |
99 | ||
100 | mutex_unlock(&data->update_lock); | |
101 | ||
102 | return data; | |
103 | } | |
104 | ||
105 | /* Return the voltage from the given register in millivolts */ | |
106 | static int ltc4245_get_voltage(struct device *dev, u8 reg) | |
107 | { | |
108 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
109 | const u8 regval = data->vregs[reg - 0x10]; | |
110 | u32 voltage = 0; | |
111 | ||
112 | switch (reg) { | |
113 | case LTC4245_12VIN: | |
114 | case LTC4245_12VOUT: | |
115 | voltage = regval * 55; | |
116 | break; | |
117 | case LTC4245_5VIN: | |
118 | case LTC4245_5VOUT: | |
119 | voltage = regval * 22; | |
120 | break; | |
121 | case LTC4245_3VIN: | |
122 | case LTC4245_3VOUT: | |
123 | voltage = regval * 15; | |
124 | break; | |
125 | case LTC4245_VEEIN: | |
126 | case LTC4245_VEEOUT: | |
127 | voltage = regval * -55; | |
128 | break; | |
df16dd53 | 129 | case LTC4245_GPIOADC: |
6e34b187 IS |
130 | voltage = regval * 10; |
131 | break; | |
132 | default: | |
133 | /* If we get here, the developer messed up */ | |
134 | WARN_ON_ONCE(1); | |
135 | break; | |
136 | } | |
137 | ||
138 | return voltage; | |
139 | } | |
140 | ||
141 | /* Return the current in the given sense register in milliAmperes */ | |
142 | static unsigned int ltc4245_get_current(struct device *dev, u8 reg) | |
143 | { | |
144 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
145 | const u8 regval = data->vregs[reg - 0x10]; | |
146 | unsigned int voltage; | |
147 | unsigned int curr; | |
148 | ||
149 | /* The strange looking conversions that follow are fixed-point | |
150 | * math, since we cannot do floating point in the kernel. | |
151 | * | |
152 | * Step 1: convert sense register to microVolts | |
153 | * Step 2: convert voltage to milliAmperes | |
154 | * | |
155 | * If you play around with the V=IR equation, you come up with | |
156 | * the following: X uV / Y mOhm == Z mA | |
157 | * | |
158 | * With the resistors that are fractions of a milliOhm, we multiply | |
159 | * the voltage and resistance by 10, to shift the decimal point. | |
160 | * Now we can use the normal division operator again. | |
161 | */ | |
162 | ||
163 | switch (reg) { | |
164 | case LTC4245_12VSENSE: | |
165 | voltage = regval * 250; /* voltage in uV */ | |
166 | curr = voltage / 50; /* sense resistor 50 mOhm */ | |
167 | break; | |
168 | case LTC4245_5VSENSE: | |
169 | voltage = regval * 125; /* voltage in uV */ | |
170 | curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */ | |
171 | break; | |
172 | case LTC4245_3VSENSE: | |
173 | voltage = regval * 125; /* voltage in uV */ | |
174 | curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */ | |
175 | break; | |
176 | case LTC4245_VEESENSE: | |
177 | voltage = regval * 250; /* voltage in uV */ | |
178 | curr = voltage / 100; /* sense resistor 100 mOhm */ | |
179 | break; | |
180 | default: | |
181 | /* If we get here, the developer messed up */ | |
182 | WARN_ON_ONCE(1); | |
183 | curr = 0; | |
184 | break; | |
185 | } | |
186 | ||
187 | return curr; | |
188 | } | |
189 | ||
190 | static ssize_t ltc4245_show_voltage(struct device *dev, | |
191 | struct device_attribute *da, | |
192 | char *buf) | |
193 | { | |
194 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
195 | const int voltage = ltc4245_get_voltage(dev, attr->index); | |
196 | ||
197 | return snprintf(buf, PAGE_SIZE, "%d\n", voltage); | |
198 | } | |
199 | ||
200 | static ssize_t ltc4245_show_current(struct device *dev, | |
201 | struct device_attribute *da, | |
202 | char *buf) | |
203 | { | |
204 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
205 | const unsigned int curr = ltc4245_get_current(dev, attr->index); | |
206 | ||
207 | return snprintf(buf, PAGE_SIZE, "%u\n", curr); | |
208 | } | |
209 | ||
210 | static ssize_t ltc4245_show_power(struct device *dev, | |
211 | struct device_attribute *da, | |
212 | char *buf) | |
213 | { | |
214 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
215 | const unsigned int curr = ltc4245_get_current(dev, attr->index); | |
216 | const int output_voltage = ltc4245_get_voltage(dev, attr->index+1); | |
217 | ||
218 | /* current in mA * voltage in mV == power in uW */ | |
219 | const unsigned int power = abs(output_voltage * curr); | |
220 | ||
221 | return snprintf(buf, PAGE_SIZE, "%u\n", power); | |
222 | } | |
223 | ||
224 | static ssize_t ltc4245_show_alarm(struct device *dev, | |
225 | struct device_attribute *da, | |
226 | char *buf) | |
227 | { | |
228 | struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da); | |
229 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
230 | const u8 reg = data->cregs[attr->index]; | |
231 | const u32 mask = attr->nr; | |
232 | ||
233 | return snprintf(buf, PAGE_SIZE, "%u\n", (reg & mask) ? 1 : 0); | |
234 | } | |
235 | ||
236 | /* These macros are used below in constructing device attribute objects | |
237 | * for use with sysfs_create_group() to make a sysfs device file | |
238 | * for each register. | |
239 | */ | |
240 | ||
241 | #define LTC4245_VOLTAGE(name, ltc4245_cmd_idx) \ | |
242 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
243 | ltc4245_show_voltage, NULL, ltc4245_cmd_idx) | |
244 | ||
245 | #define LTC4245_CURRENT(name, ltc4245_cmd_idx) \ | |
246 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
247 | ltc4245_show_current, NULL, ltc4245_cmd_idx) | |
248 | ||
249 | #define LTC4245_POWER(name, ltc4245_cmd_idx) \ | |
250 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
251 | ltc4245_show_power, NULL, ltc4245_cmd_idx) | |
252 | ||
253 | #define LTC4245_ALARM(name, mask, reg) \ | |
254 | static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \ | |
255 | ltc4245_show_alarm, NULL, (mask), reg) | |
256 | ||
257 | /* Construct a sensor_device_attribute structure for each register */ | |
258 | ||
259 | /* Input voltages */ | |
260 | LTC4245_VOLTAGE(in1_input, LTC4245_12VIN); | |
261 | LTC4245_VOLTAGE(in2_input, LTC4245_5VIN); | |
262 | LTC4245_VOLTAGE(in3_input, LTC4245_3VIN); | |
263 | LTC4245_VOLTAGE(in4_input, LTC4245_VEEIN); | |
264 | ||
265 | /* Input undervoltage alarms */ | |
266 | LTC4245_ALARM(in1_min_alarm, (1 << 0), LTC4245_FAULT1); | |
267 | LTC4245_ALARM(in2_min_alarm, (1 << 1), LTC4245_FAULT1); | |
268 | LTC4245_ALARM(in3_min_alarm, (1 << 2), LTC4245_FAULT1); | |
269 | LTC4245_ALARM(in4_min_alarm, (1 << 3), LTC4245_FAULT1); | |
270 | ||
271 | /* Currents (via sense resistor) */ | |
272 | LTC4245_CURRENT(curr1_input, LTC4245_12VSENSE); | |
273 | LTC4245_CURRENT(curr2_input, LTC4245_5VSENSE); | |
274 | LTC4245_CURRENT(curr3_input, LTC4245_3VSENSE); | |
275 | LTC4245_CURRENT(curr4_input, LTC4245_VEESENSE); | |
276 | ||
277 | /* Overcurrent alarms */ | |
278 | LTC4245_ALARM(curr1_max_alarm, (1 << 4), LTC4245_FAULT1); | |
279 | LTC4245_ALARM(curr2_max_alarm, (1 << 5), LTC4245_FAULT1); | |
280 | LTC4245_ALARM(curr3_max_alarm, (1 << 6), LTC4245_FAULT1); | |
281 | LTC4245_ALARM(curr4_max_alarm, (1 << 7), LTC4245_FAULT1); | |
282 | ||
283 | /* Output voltages */ | |
284 | LTC4245_VOLTAGE(in5_input, LTC4245_12VOUT); | |
285 | LTC4245_VOLTAGE(in6_input, LTC4245_5VOUT); | |
286 | LTC4245_VOLTAGE(in7_input, LTC4245_3VOUT); | |
287 | LTC4245_VOLTAGE(in8_input, LTC4245_VEEOUT); | |
288 | ||
289 | /* Power Bad alarms */ | |
290 | LTC4245_ALARM(in5_min_alarm, (1 << 0), LTC4245_FAULT2); | |
291 | LTC4245_ALARM(in6_min_alarm, (1 << 1), LTC4245_FAULT2); | |
292 | LTC4245_ALARM(in7_min_alarm, (1 << 2), LTC4245_FAULT2); | |
293 | LTC4245_ALARM(in8_min_alarm, (1 << 3), LTC4245_FAULT2); | |
294 | ||
295 | /* GPIO voltages */ | |
df16dd53 | 296 | LTC4245_VOLTAGE(in9_input, LTC4245_GPIOADC); |
6e34b187 IS |
297 | |
298 | /* Power Consumption (virtual) */ | |
299 | LTC4245_POWER(power1_input, LTC4245_12VSENSE); | |
300 | LTC4245_POWER(power2_input, LTC4245_5VSENSE); | |
301 | LTC4245_POWER(power3_input, LTC4245_3VSENSE); | |
302 | LTC4245_POWER(power4_input, LTC4245_VEESENSE); | |
303 | ||
304 | /* Finally, construct an array of pointers to members of the above objects, | |
305 | * as required for sysfs_create_group() | |
306 | */ | |
307 | static struct attribute *ltc4245_attributes[] = { | |
308 | &sensor_dev_attr_in1_input.dev_attr.attr, | |
309 | &sensor_dev_attr_in2_input.dev_attr.attr, | |
310 | &sensor_dev_attr_in3_input.dev_attr.attr, | |
311 | &sensor_dev_attr_in4_input.dev_attr.attr, | |
312 | ||
313 | &sensor_dev_attr_in1_min_alarm.dev_attr.attr, | |
314 | &sensor_dev_attr_in2_min_alarm.dev_attr.attr, | |
315 | &sensor_dev_attr_in3_min_alarm.dev_attr.attr, | |
316 | &sensor_dev_attr_in4_min_alarm.dev_attr.attr, | |
317 | ||
318 | &sensor_dev_attr_curr1_input.dev_attr.attr, | |
319 | &sensor_dev_attr_curr2_input.dev_attr.attr, | |
320 | &sensor_dev_attr_curr3_input.dev_attr.attr, | |
321 | &sensor_dev_attr_curr4_input.dev_attr.attr, | |
322 | ||
323 | &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, | |
324 | &sensor_dev_attr_curr2_max_alarm.dev_attr.attr, | |
325 | &sensor_dev_attr_curr3_max_alarm.dev_attr.attr, | |
326 | &sensor_dev_attr_curr4_max_alarm.dev_attr.attr, | |
327 | ||
328 | &sensor_dev_attr_in5_input.dev_attr.attr, | |
329 | &sensor_dev_attr_in6_input.dev_attr.attr, | |
330 | &sensor_dev_attr_in7_input.dev_attr.attr, | |
331 | &sensor_dev_attr_in8_input.dev_attr.attr, | |
332 | ||
333 | &sensor_dev_attr_in5_min_alarm.dev_attr.attr, | |
334 | &sensor_dev_attr_in6_min_alarm.dev_attr.attr, | |
335 | &sensor_dev_attr_in7_min_alarm.dev_attr.attr, | |
336 | &sensor_dev_attr_in8_min_alarm.dev_attr.attr, | |
337 | ||
338 | &sensor_dev_attr_in9_input.dev_attr.attr, | |
6e34b187 IS |
339 | |
340 | &sensor_dev_attr_power1_input.dev_attr.attr, | |
341 | &sensor_dev_attr_power2_input.dev_attr.attr, | |
342 | &sensor_dev_attr_power3_input.dev_attr.attr, | |
343 | &sensor_dev_attr_power4_input.dev_attr.attr, | |
344 | ||
345 | NULL, | |
346 | }; | |
347 | ||
348 | static const struct attribute_group ltc4245_group = { | |
349 | .attrs = ltc4245_attributes, | |
350 | }; | |
351 | ||
352 | static int ltc4245_probe(struct i2c_client *client, | |
353 | const struct i2c_device_id *id) | |
354 | { | |
2d2a7cff | 355 | struct i2c_adapter *adapter = client->adapter; |
6e34b187 IS |
356 | struct ltc4245_data *data; |
357 | int ret; | |
358 | ||
2d2a7cff JD |
359 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
360 | return -ENODEV; | |
361 | ||
6e34b187 IS |
362 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
363 | if (!data) { | |
364 | ret = -ENOMEM; | |
365 | goto out_kzalloc; | |
366 | } | |
367 | ||
368 | i2c_set_clientdata(client, data); | |
369 | mutex_init(&data->update_lock); | |
370 | ||
371 | /* Initialize the LTC4245 chip */ | |
58f055e5 IS |
372 | i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00); |
373 | i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00); | |
6e34b187 IS |
374 | |
375 | /* Register sysfs hooks */ | |
376 | ret = sysfs_create_group(&client->dev.kobj, <c4245_group); | |
377 | if (ret) | |
378 | goto out_sysfs_create_group; | |
379 | ||
380 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
381 | if (IS_ERR(data->hwmon_dev)) { | |
382 | ret = PTR_ERR(data->hwmon_dev); | |
383 | goto out_hwmon_device_register; | |
384 | } | |
385 | ||
386 | return 0; | |
387 | ||
388 | out_hwmon_device_register: | |
389 | sysfs_remove_group(&client->dev.kobj, <c4245_group); | |
390 | out_sysfs_create_group: | |
391 | kfree(data); | |
392 | out_kzalloc: | |
393 | return ret; | |
394 | } | |
395 | ||
396 | static int ltc4245_remove(struct i2c_client *client) | |
397 | { | |
398 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
399 | ||
400 | hwmon_device_unregister(data->hwmon_dev); | |
401 | sysfs_remove_group(&client->dev.kobj, <c4245_group); | |
402 | ||
403 | kfree(data); | |
404 | ||
405 | return 0; | |
406 | } | |
407 | ||
6e34b187 | 408 | static const struct i2c_device_id ltc4245_id[] = { |
2d2a7cff | 409 | { "ltc4245", 0 }, |
6e34b187 IS |
410 | { } |
411 | }; | |
412 | MODULE_DEVICE_TABLE(i2c, ltc4245_id); | |
413 | ||
414 | /* This is the driver that will be inserted */ | |
415 | static struct i2c_driver ltc4245_driver = { | |
6e34b187 IS |
416 | .driver = { |
417 | .name = "ltc4245", | |
418 | }, | |
419 | .probe = ltc4245_probe, | |
420 | .remove = ltc4245_remove, | |
421 | .id_table = ltc4245_id, | |
6e34b187 IS |
422 | }; |
423 | ||
424 | static int __init ltc4245_init(void) | |
425 | { | |
426 | return i2c_add_driver(<c4245_driver); | |
427 | } | |
428 | ||
429 | static void __exit ltc4245_exit(void) | |
430 | { | |
431 | i2c_del_driver(<c4245_driver); | |
432 | } | |
433 | ||
434 | MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); | |
435 | MODULE_DESCRIPTION("LTC4245 driver"); | |
436 | MODULE_LICENSE("GPL"); | |
437 | ||
438 | module_init(ltc4245_init); | |
439 | module_exit(ltc4245_exit); |