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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> | |
dcd8f392 | 24 | #include <linux/jiffies.h> |
5950ec8d | 25 | #include <linux/i2c/ltc4245.h> |
6e34b187 | 26 | |
6e34b187 IS |
27 | /* Here are names of the chip's registers (a.k.a. commands) */ |
28 | enum ltc4245_cmd { | |
29 | LTC4245_STATUS = 0x00, /* readonly */ | |
30 | LTC4245_ALERT = 0x01, | |
31 | LTC4245_CONTROL = 0x02, | |
32 | LTC4245_ON = 0x03, | |
33 | LTC4245_FAULT1 = 0x04, | |
34 | LTC4245_FAULT2 = 0x05, | |
35 | LTC4245_GPIO = 0x06, | |
36 | LTC4245_ADCADR = 0x07, | |
37 | ||
38 | LTC4245_12VIN = 0x10, | |
39 | LTC4245_12VSENSE = 0x11, | |
40 | LTC4245_12VOUT = 0x12, | |
41 | LTC4245_5VIN = 0x13, | |
42 | LTC4245_5VSENSE = 0x14, | |
43 | LTC4245_5VOUT = 0x15, | |
44 | LTC4245_3VIN = 0x16, | |
45 | LTC4245_3VSENSE = 0x17, | |
46 | LTC4245_3VOUT = 0x18, | |
47 | LTC4245_VEEIN = 0x19, | |
48 | LTC4245_VEESENSE = 0x1a, | |
49 | LTC4245_VEEOUT = 0x1b, | |
df16dd53 | 50 | LTC4245_GPIOADC = 0x1c, |
6e34b187 IS |
51 | }; |
52 | ||
53 | struct ltc4245_data { | |
54 | struct device *hwmon_dev; | |
55 | ||
56 | struct mutex update_lock; | |
57 | bool valid; | |
58 | unsigned long last_updated; /* in jiffies */ | |
59 | ||
60 | /* Control registers */ | |
61 | u8 cregs[0x08]; | |
62 | ||
63 | /* Voltage registers */ | |
df16dd53 | 64 | u8 vregs[0x0d]; |
5950ec8d IS |
65 | |
66 | /* GPIO ADC registers */ | |
67 | bool use_extra_gpios; | |
68 | int gpios[3]; | |
6e34b187 IS |
69 | }; |
70 | ||
5950ec8d IS |
71 | /* |
72 | * Update the readings from the GPIO pins. If the driver has been configured to | |
73 | * sample all GPIO's as analog voltages, a round-robin sampling method is used. | |
74 | * Otherwise, only the configured GPIO pin is sampled. | |
75 | * | |
76 | * LOCKING: must hold data->update_lock | |
77 | */ | |
78 | static void ltc4245_update_gpios(struct device *dev) | |
79 | { | |
80 | struct i2c_client *client = to_i2c_client(dev); | |
81 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
82 | u8 gpio_curr, gpio_next, gpio_reg; | |
83 | int i; | |
84 | ||
85 | /* no extra gpio support, we're basically done */ | |
86 | if (!data->use_extra_gpios) { | |
87 | data->gpios[0] = data->vregs[LTC4245_GPIOADC - 0x10]; | |
88 | return; | |
89 | } | |
90 | ||
91 | /* | |
92 | * If the last reading was too long ago, then we mark all old GPIO | |
93 | * readings as stale by setting them to -EAGAIN | |
94 | */ | |
95 | if (time_after(jiffies, data->last_updated + 5 * HZ)) { | |
96 | dev_dbg(&client->dev, "Marking GPIOs invalid\n"); | |
97 | for (i = 0; i < ARRAY_SIZE(data->gpios); i++) | |
98 | data->gpios[i] = -EAGAIN; | |
99 | } | |
100 | ||
101 | /* | |
102 | * Get the current GPIO pin | |
103 | * | |
104 | * The datasheet calls these GPIO[1-3], but we'll calculate the zero | |
105 | * based array index instead, and call them GPIO[0-2]. This is much | |
106 | * easier to think about. | |
107 | */ | |
108 | gpio_curr = (data->cregs[LTC4245_GPIO] & 0xc0) >> 6; | |
109 | if (gpio_curr > 0) | |
110 | gpio_curr -= 1; | |
111 | ||
112 | /* Read the GPIO voltage from the GPIOADC register */ | |
113 | data->gpios[gpio_curr] = data->vregs[LTC4245_GPIOADC - 0x10]; | |
114 | ||
115 | /* Find the next GPIO pin to read */ | |
116 | gpio_next = (gpio_curr + 1) % ARRAY_SIZE(data->gpios); | |
117 | ||
118 | /* | |
119 | * Calculate the correct setting for the GPIO register so it will | |
120 | * sample the next GPIO pin | |
121 | */ | |
122 | gpio_reg = (data->cregs[LTC4245_GPIO] & 0x3f) | ((gpio_next + 1) << 6); | |
123 | ||
124 | /* Update the GPIO register */ | |
125 | i2c_smbus_write_byte_data(client, LTC4245_GPIO, gpio_reg); | |
126 | ||
127 | /* Update saved data */ | |
128 | data->cregs[LTC4245_GPIO] = gpio_reg; | |
129 | } | |
130 | ||
6e34b187 IS |
131 | static struct ltc4245_data *ltc4245_update_device(struct device *dev) |
132 | { | |
133 | struct i2c_client *client = to_i2c_client(dev); | |
134 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
135 | s32 val; | |
136 | int i; | |
137 | ||
138 | mutex_lock(&data->update_lock); | |
139 | ||
140 | if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { | |
141 | ||
142 | dev_dbg(&client->dev, "Starting ltc4245 update\n"); | |
143 | ||
144 | /* Read control registers -- 0x00 to 0x07 */ | |
145 | for (i = 0; i < ARRAY_SIZE(data->cregs); i++) { | |
146 | val = i2c_smbus_read_byte_data(client, i); | |
147 | if (unlikely(val < 0)) | |
148 | data->cregs[i] = 0; | |
149 | else | |
150 | data->cregs[i] = val; | |
151 | } | |
152 | ||
df16dd53 | 153 | /* Read voltage registers -- 0x10 to 0x1c */ |
6e34b187 IS |
154 | for (i = 0; i < ARRAY_SIZE(data->vregs); i++) { |
155 | val = i2c_smbus_read_byte_data(client, i+0x10); | |
156 | if (unlikely(val < 0)) | |
157 | data->vregs[i] = 0; | |
158 | else | |
159 | data->vregs[i] = val; | |
160 | } | |
161 | ||
5950ec8d IS |
162 | /* Update GPIO readings */ |
163 | ltc4245_update_gpios(dev); | |
164 | ||
6e34b187 IS |
165 | data->last_updated = jiffies; |
166 | data->valid = 1; | |
167 | } | |
168 | ||
169 | mutex_unlock(&data->update_lock); | |
170 | ||
171 | return data; | |
172 | } | |
173 | ||
174 | /* Return the voltage from the given register in millivolts */ | |
175 | static int ltc4245_get_voltage(struct device *dev, u8 reg) | |
176 | { | |
177 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
178 | const u8 regval = data->vregs[reg - 0x10]; | |
179 | u32 voltage = 0; | |
180 | ||
181 | switch (reg) { | |
182 | case LTC4245_12VIN: | |
183 | case LTC4245_12VOUT: | |
184 | voltage = regval * 55; | |
185 | break; | |
186 | case LTC4245_5VIN: | |
187 | case LTC4245_5VOUT: | |
188 | voltage = regval * 22; | |
189 | break; | |
190 | case LTC4245_3VIN: | |
191 | case LTC4245_3VOUT: | |
192 | voltage = regval * 15; | |
193 | break; | |
194 | case LTC4245_VEEIN: | |
195 | case LTC4245_VEEOUT: | |
196 | voltage = regval * -55; | |
197 | break; | |
df16dd53 | 198 | case LTC4245_GPIOADC: |
6e34b187 IS |
199 | voltage = regval * 10; |
200 | break; | |
201 | default: | |
202 | /* If we get here, the developer messed up */ | |
203 | WARN_ON_ONCE(1); | |
204 | break; | |
205 | } | |
206 | ||
207 | return voltage; | |
208 | } | |
209 | ||
210 | /* Return the current in the given sense register in milliAmperes */ | |
211 | static unsigned int ltc4245_get_current(struct device *dev, u8 reg) | |
212 | { | |
213 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
214 | const u8 regval = data->vregs[reg - 0x10]; | |
215 | unsigned int voltage; | |
216 | unsigned int curr; | |
217 | ||
430b4fcd GR |
218 | /* |
219 | * The strange looking conversions that follow are fixed-point | |
6e34b187 IS |
220 | * math, since we cannot do floating point in the kernel. |
221 | * | |
222 | * Step 1: convert sense register to microVolts | |
223 | * Step 2: convert voltage to milliAmperes | |
224 | * | |
225 | * If you play around with the V=IR equation, you come up with | |
226 | * the following: X uV / Y mOhm == Z mA | |
227 | * | |
228 | * With the resistors that are fractions of a milliOhm, we multiply | |
229 | * the voltage and resistance by 10, to shift the decimal point. | |
230 | * Now we can use the normal division operator again. | |
231 | */ | |
232 | ||
233 | switch (reg) { | |
234 | case LTC4245_12VSENSE: | |
235 | voltage = regval * 250; /* voltage in uV */ | |
236 | curr = voltage / 50; /* sense resistor 50 mOhm */ | |
237 | break; | |
238 | case LTC4245_5VSENSE: | |
239 | voltage = regval * 125; /* voltage in uV */ | |
240 | curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */ | |
241 | break; | |
242 | case LTC4245_3VSENSE: | |
243 | voltage = regval * 125; /* voltage in uV */ | |
244 | curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */ | |
245 | break; | |
246 | case LTC4245_VEESENSE: | |
247 | voltage = regval * 250; /* voltage in uV */ | |
248 | curr = voltage / 100; /* sense resistor 100 mOhm */ | |
249 | break; | |
250 | default: | |
251 | /* If we get here, the developer messed up */ | |
252 | WARN_ON_ONCE(1); | |
253 | curr = 0; | |
254 | break; | |
255 | } | |
256 | ||
257 | return curr; | |
258 | } | |
259 | ||
260 | static ssize_t ltc4245_show_voltage(struct device *dev, | |
261 | struct device_attribute *da, | |
262 | char *buf) | |
263 | { | |
264 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
265 | const int voltage = ltc4245_get_voltage(dev, attr->index); | |
266 | ||
267 | return snprintf(buf, PAGE_SIZE, "%d\n", voltage); | |
268 | } | |
269 | ||
270 | static ssize_t ltc4245_show_current(struct device *dev, | |
271 | struct device_attribute *da, | |
272 | char *buf) | |
273 | { | |
274 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
275 | const unsigned int curr = ltc4245_get_current(dev, attr->index); | |
276 | ||
277 | return snprintf(buf, PAGE_SIZE, "%u\n", curr); | |
278 | } | |
279 | ||
280 | static ssize_t ltc4245_show_power(struct device *dev, | |
281 | struct device_attribute *da, | |
282 | char *buf) | |
283 | { | |
284 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
285 | const unsigned int curr = ltc4245_get_current(dev, attr->index); | |
286 | const int output_voltage = ltc4245_get_voltage(dev, attr->index+1); | |
287 | ||
288 | /* current in mA * voltage in mV == power in uW */ | |
289 | const unsigned int power = abs(output_voltage * curr); | |
290 | ||
291 | return snprintf(buf, PAGE_SIZE, "%u\n", power); | |
292 | } | |
293 | ||
294 | static ssize_t ltc4245_show_alarm(struct device *dev, | |
295 | struct device_attribute *da, | |
296 | char *buf) | |
297 | { | |
298 | struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da); | |
299 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
300 | const u8 reg = data->cregs[attr->index]; | |
301 | const u32 mask = attr->nr; | |
302 | ||
303 | return snprintf(buf, PAGE_SIZE, "%u\n", (reg & mask) ? 1 : 0); | |
304 | } | |
305 | ||
5950ec8d IS |
306 | static ssize_t ltc4245_show_gpio(struct device *dev, |
307 | struct device_attribute *da, | |
308 | char *buf) | |
309 | { | |
310 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
311 | struct ltc4245_data *data = ltc4245_update_device(dev); | |
312 | int val = data->gpios[attr->index]; | |
313 | ||
314 | /* handle stale GPIO's */ | |
315 | if (val < 0) | |
316 | return val; | |
317 | ||
318 | /* Convert to millivolts and print */ | |
319 | return snprintf(buf, PAGE_SIZE, "%u\n", val * 10); | |
320 | } | |
321 | ||
430b4fcd GR |
322 | /* |
323 | * These macros are used below in constructing device attribute objects | |
6e34b187 IS |
324 | * for use with sysfs_create_group() to make a sysfs device file |
325 | * for each register. | |
326 | */ | |
327 | ||
328 | #define LTC4245_VOLTAGE(name, ltc4245_cmd_idx) \ | |
329 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
330 | ltc4245_show_voltage, NULL, ltc4245_cmd_idx) | |
331 | ||
332 | #define LTC4245_CURRENT(name, ltc4245_cmd_idx) \ | |
333 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
334 | ltc4245_show_current, NULL, ltc4245_cmd_idx) | |
335 | ||
336 | #define LTC4245_POWER(name, ltc4245_cmd_idx) \ | |
337 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
338 | ltc4245_show_power, NULL, ltc4245_cmd_idx) | |
339 | ||
340 | #define LTC4245_ALARM(name, mask, reg) \ | |
341 | static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \ | |
342 | ltc4245_show_alarm, NULL, (mask), reg) | |
343 | ||
5950ec8d IS |
344 | #define LTC4245_GPIO_VOLTAGE(name, gpio_num) \ |
345 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ | |
346 | ltc4245_show_gpio, NULL, gpio_num) | |
347 | ||
6e34b187 IS |
348 | /* Construct a sensor_device_attribute structure for each register */ |
349 | ||
350 | /* Input voltages */ | |
351 | LTC4245_VOLTAGE(in1_input, LTC4245_12VIN); | |
352 | LTC4245_VOLTAGE(in2_input, LTC4245_5VIN); | |
353 | LTC4245_VOLTAGE(in3_input, LTC4245_3VIN); | |
354 | LTC4245_VOLTAGE(in4_input, LTC4245_VEEIN); | |
355 | ||
356 | /* Input undervoltage alarms */ | |
357 | LTC4245_ALARM(in1_min_alarm, (1 << 0), LTC4245_FAULT1); | |
358 | LTC4245_ALARM(in2_min_alarm, (1 << 1), LTC4245_FAULT1); | |
359 | LTC4245_ALARM(in3_min_alarm, (1 << 2), LTC4245_FAULT1); | |
360 | LTC4245_ALARM(in4_min_alarm, (1 << 3), LTC4245_FAULT1); | |
361 | ||
362 | /* Currents (via sense resistor) */ | |
363 | LTC4245_CURRENT(curr1_input, LTC4245_12VSENSE); | |
364 | LTC4245_CURRENT(curr2_input, LTC4245_5VSENSE); | |
365 | LTC4245_CURRENT(curr3_input, LTC4245_3VSENSE); | |
366 | LTC4245_CURRENT(curr4_input, LTC4245_VEESENSE); | |
367 | ||
368 | /* Overcurrent alarms */ | |
369 | LTC4245_ALARM(curr1_max_alarm, (1 << 4), LTC4245_FAULT1); | |
370 | LTC4245_ALARM(curr2_max_alarm, (1 << 5), LTC4245_FAULT1); | |
371 | LTC4245_ALARM(curr3_max_alarm, (1 << 6), LTC4245_FAULT1); | |
372 | LTC4245_ALARM(curr4_max_alarm, (1 << 7), LTC4245_FAULT1); | |
373 | ||
374 | /* Output voltages */ | |
375 | LTC4245_VOLTAGE(in5_input, LTC4245_12VOUT); | |
376 | LTC4245_VOLTAGE(in6_input, LTC4245_5VOUT); | |
377 | LTC4245_VOLTAGE(in7_input, LTC4245_3VOUT); | |
378 | LTC4245_VOLTAGE(in8_input, LTC4245_VEEOUT); | |
379 | ||
380 | /* Power Bad alarms */ | |
381 | LTC4245_ALARM(in5_min_alarm, (1 << 0), LTC4245_FAULT2); | |
382 | LTC4245_ALARM(in6_min_alarm, (1 << 1), LTC4245_FAULT2); | |
383 | LTC4245_ALARM(in7_min_alarm, (1 << 2), LTC4245_FAULT2); | |
384 | LTC4245_ALARM(in8_min_alarm, (1 << 3), LTC4245_FAULT2); | |
385 | ||
386 | /* GPIO voltages */ | |
5950ec8d IS |
387 | LTC4245_GPIO_VOLTAGE(in9_input, 0); |
388 | LTC4245_GPIO_VOLTAGE(in10_input, 1); | |
389 | LTC4245_GPIO_VOLTAGE(in11_input, 2); | |
6e34b187 IS |
390 | |
391 | /* Power Consumption (virtual) */ | |
392 | LTC4245_POWER(power1_input, LTC4245_12VSENSE); | |
393 | LTC4245_POWER(power2_input, LTC4245_5VSENSE); | |
394 | LTC4245_POWER(power3_input, LTC4245_3VSENSE); | |
395 | LTC4245_POWER(power4_input, LTC4245_VEESENSE); | |
396 | ||
430b4fcd GR |
397 | /* |
398 | * Finally, construct an array of pointers to members of the above objects, | |
6e34b187 IS |
399 | * as required for sysfs_create_group() |
400 | */ | |
5950ec8d | 401 | static struct attribute *ltc4245_std_attributes[] = { |
6e34b187 IS |
402 | &sensor_dev_attr_in1_input.dev_attr.attr, |
403 | &sensor_dev_attr_in2_input.dev_attr.attr, | |
404 | &sensor_dev_attr_in3_input.dev_attr.attr, | |
405 | &sensor_dev_attr_in4_input.dev_attr.attr, | |
406 | ||
407 | &sensor_dev_attr_in1_min_alarm.dev_attr.attr, | |
408 | &sensor_dev_attr_in2_min_alarm.dev_attr.attr, | |
409 | &sensor_dev_attr_in3_min_alarm.dev_attr.attr, | |
410 | &sensor_dev_attr_in4_min_alarm.dev_attr.attr, | |
411 | ||
412 | &sensor_dev_attr_curr1_input.dev_attr.attr, | |
413 | &sensor_dev_attr_curr2_input.dev_attr.attr, | |
414 | &sensor_dev_attr_curr3_input.dev_attr.attr, | |
415 | &sensor_dev_attr_curr4_input.dev_attr.attr, | |
416 | ||
417 | &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, | |
418 | &sensor_dev_attr_curr2_max_alarm.dev_attr.attr, | |
419 | &sensor_dev_attr_curr3_max_alarm.dev_attr.attr, | |
420 | &sensor_dev_attr_curr4_max_alarm.dev_attr.attr, | |
421 | ||
422 | &sensor_dev_attr_in5_input.dev_attr.attr, | |
423 | &sensor_dev_attr_in6_input.dev_attr.attr, | |
424 | &sensor_dev_attr_in7_input.dev_attr.attr, | |
425 | &sensor_dev_attr_in8_input.dev_attr.attr, | |
426 | ||
427 | &sensor_dev_attr_in5_min_alarm.dev_attr.attr, | |
428 | &sensor_dev_attr_in6_min_alarm.dev_attr.attr, | |
429 | &sensor_dev_attr_in7_min_alarm.dev_attr.attr, | |
430 | &sensor_dev_attr_in8_min_alarm.dev_attr.attr, | |
431 | ||
432 | &sensor_dev_attr_in9_input.dev_attr.attr, | |
6e34b187 IS |
433 | |
434 | &sensor_dev_attr_power1_input.dev_attr.attr, | |
435 | &sensor_dev_attr_power2_input.dev_attr.attr, | |
436 | &sensor_dev_attr_power3_input.dev_attr.attr, | |
437 | &sensor_dev_attr_power4_input.dev_attr.attr, | |
438 | ||
439 | NULL, | |
440 | }; | |
441 | ||
5950ec8d IS |
442 | static struct attribute *ltc4245_gpio_attributes[] = { |
443 | &sensor_dev_attr_in10_input.dev_attr.attr, | |
444 | &sensor_dev_attr_in11_input.dev_attr.attr, | |
445 | NULL, | |
446 | }; | |
447 | ||
448 | static const struct attribute_group ltc4245_std_group = { | |
449 | .attrs = ltc4245_std_attributes, | |
450 | }; | |
451 | ||
452 | static const struct attribute_group ltc4245_gpio_group = { | |
453 | .attrs = ltc4245_gpio_attributes, | |
6e34b187 IS |
454 | }; |
455 | ||
5950ec8d IS |
456 | static int ltc4245_sysfs_create_groups(struct i2c_client *client) |
457 | { | |
458 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
459 | struct device *dev = &client->dev; | |
460 | int ret; | |
461 | ||
462 | /* register the standard sysfs attributes */ | |
463 | ret = sysfs_create_group(&dev->kobj, <c4245_std_group); | |
464 | if (ret) { | |
465 | dev_err(dev, "unable to register standard attributes\n"); | |
466 | return ret; | |
467 | } | |
468 | ||
469 | /* if we're using the extra gpio support, register it's attributes */ | |
470 | if (data->use_extra_gpios) { | |
471 | ret = sysfs_create_group(&dev->kobj, <c4245_gpio_group); | |
472 | if (ret) { | |
473 | dev_err(dev, "unable to register gpio attributes\n"); | |
474 | sysfs_remove_group(&dev->kobj, <c4245_std_group); | |
475 | return ret; | |
476 | } | |
477 | } | |
478 | ||
479 | return 0; | |
480 | } | |
481 | ||
482 | static void ltc4245_sysfs_remove_groups(struct i2c_client *client) | |
483 | { | |
484 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
485 | struct device *dev = &client->dev; | |
486 | ||
487 | if (data->use_extra_gpios) | |
488 | sysfs_remove_group(&dev->kobj, <c4245_gpio_group); | |
489 | ||
490 | sysfs_remove_group(&dev->kobj, <c4245_std_group); | |
491 | } | |
492 | ||
493 | static bool ltc4245_use_extra_gpios(struct i2c_client *client) | |
494 | { | |
495 | struct ltc4245_platform_data *pdata = dev_get_platdata(&client->dev); | |
496 | #ifdef CONFIG_OF | |
497 | struct device_node *np = client->dev.of_node; | |
498 | #endif | |
499 | ||
500 | /* prefer platform data */ | |
501 | if (pdata) | |
502 | return pdata->use_extra_gpios; | |
503 | ||
504 | #ifdef CONFIG_OF | |
505 | /* fallback on OF */ | |
506 | if (of_find_property(np, "ltc4245,use-extra-gpios", NULL)) | |
507 | return true; | |
508 | #endif | |
509 | ||
510 | return false; | |
511 | } | |
512 | ||
6e34b187 IS |
513 | static int ltc4245_probe(struct i2c_client *client, |
514 | const struct i2c_device_id *id) | |
515 | { | |
2d2a7cff | 516 | struct i2c_adapter *adapter = client->adapter; |
6e34b187 IS |
517 | struct ltc4245_data *data; |
518 | int ret; | |
519 | ||
2d2a7cff JD |
520 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
521 | return -ENODEV; | |
522 | ||
effb8ab1 GR |
523 | data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); |
524 | if (!data) | |
525 | return -ENOMEM; | |
6e34b187 IS |
526 | |
527 | i2c_set_clientdata(client, data); | |
528 | mutex_init(&data->update_lock); | |
5950ec8d | 529 | data->use_extra_gpios = ltc4245_use_extra_gpios(client); |
6e34b187 IS |
530 | |
531 | /* Initialize the LTC4245 chip */ | |
58f055e5 IS |
532 | i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00); |
533 | i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00); | |
6e34b187 IS |
534 | |
535 | /* Register sysfs hooks */ | |
5950ec8d | 536 | ret = ltc4245_sysfs_create_groups(client); |
6e34b187 | 537 | if (ret) |
effb8ab1 | 538 | return ret; |
6e34b187 IS |
539 | |
540 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
541 | if (IS_ERR(data->hwmon_dev)) { | |
542 | ret = PTR_ERR(data->hwmon_dev); | |
543 | goto out_hwmon_device_register; | |
544 | } | |
545 | ||
546 | return 0; | |
547 | ||
548 | out_hwmon_device_register: | |
5950ec8d | 549 | ltc4245_sysfs_remove_groups(client); |
6e34b187 IS |
550 | return ret; |
551 | } | |
552 | ||
553 | static int ltc4245_remove(struct i2c_client *client) | |
554 | { | |
555 | struct ltc4245_data *data = i2c_get_clientdata(client); | |
556 | ||
557 | hwmon_device_unregister(data->hwmon_dev); | |
5950ec8d | 558 | ltc4245_sysfs_remove_groups(client); |
6e34b187 IS |
559 | |
560 | return 0; | |
561 | } | |
562 | ||
6e34b187 | 563 | static const struct i2c_device_id ltc4245_id[] = { |
2d2a7cff | 564 | { "ltc4245", 0 }, |
6e34b187 IS |
565 | { } |
566 | }; | |
567 | MODULE_DEVICE_TABLE(i2c, ltc4245_id); | |
568 | ||
569 | /* This is the driver that will be inserted */ | |
570 | static struct i2c_driver ltc4245_driver = { | |
6e34b187 IS |
571 | .driver = { |
572 | .name = "ltc4245", | |
573 | }, | |
574 | .probe = ltc4245_probe, | |
575 | .remove = ltc4245_remove, | |
576 | .id_table = ltc4245_id, | |
6e34b187 IS |
577 | }; |
578 | ||
f0967eea | 579 | module_i2c_driver(ltc4245_driver); |
6e34b187 IS |
580 | |
581 | MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); | |
582 | MODULE_DESCRIPTION("LTC4245 driver"); | |
583 | MODULE_LICENSE("GPL"); |