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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller
4 *
5 * Copyright (C) 2008 Ira W. Snyder <iws@ovro.caltech.edu>
6 *
7 * This driver is based on the ds1621 and ina209 drivers.
8 *
9 * Datasheet:
10 * http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1140,P19392,D13517
11 */
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/bitops.h>
17#include <linux/err.h>
18#include <linux/slab.h>
19#include <linux/i2c.h>
20#include <linux/hwmon.h>
21#include <linux/hwmon-sysfs.h>
22#include <linux/jiffies.h>
23#include <linux/platform_data/ltc4245.h>
24
25/* Here are names of the chip's registers (a.k.a. commands) */
26enum 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,
48 LTC4245_GPIOADC = 0x1c,
49};
50
51struct ltc4245_data {
52 struct i2c_client *client;
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 */
62 u8 vregs[0x0d];
63
64 /* GPIO ADC registers */
65 bool use_extra_gpios;
66 int gpios[3];
67};
68
69/*
70 * Update the readings from the GPIO pins. If the driver has been configured to
71 * sample all GPIO's as analog voltages, a round-robin sampling method is used.
72 * Otherwise, only the configured GPIO pin is sampled.
73 *
74 * LOCKING: must hold data->update_lock
75 */
76static void ltc4245_update_gpios(struct device *dev)
77{
78 struct ltc4245_data *data = dev_get_drvdata(dev);
79 struct i2c_client *client = data->client;
80 u8 gpio_curr, gpio_next, gpio_reg;
81 int i;
82
83 /* no extra gpio support, we're basically done */
84 if (!data->use_extra_gpios) {
85 data->gpios[0] = data->vregs[LTC4245_GPIOADC - 0x10];
86 return;
87 }
88
89 /*
90 * If the last reading was too long ago, then we mark all old GPIO
91 * readings as stale by setting them to -EAGAIN
92 */
93 if (time_after(jiffies, data->last_updated + 5 * HZ)) {
94 for (i = 0; i < ARRAY_SIZE(data->gpios); i++)
95 data->gpios[i] = -EAGAIN;
96 }
97
98 /*
99 * Get the current GPIO pin
100 *
101 * The datasheet calls these GPIO[1-3], but we'll calculate the zero
102 * based array index instead, and call them GPIO[0-2]. This is much
103 * easier to think about.
104 */
105 gpio_curr = (data->cregs[LTC4245_GPIO] & 0xc0) >> 6;
106 if (gpio_curr > 0)
107 gpio_curr -= 1;
108
109 /* Read the GPIO voltage from the GPIOADC register */
110 data->gpios[gpio_curr] = data->vregs[LTC4245_GPIOADC - 0x10];
111
112 /* Find the next GPIO pin to read */
113 gpio_next = (gpio_curr + 1) % ARRAY_SIZE(data->gpios);
114
115 /*
116 * Calculate the correct setting for the GPIO register so it will
117 * sample the next GPIO pin
118 */
119 gpio_reg = (data->cregs[LTC4245_GPIO] & 0x3f) | ((gpio_next + 1) << 6);
120
121 /* Update the GPIO register */
122 i2c_smbus_write_byte_data(client, LTC4245_GPIO, gpio_reg);
123
124 /* Update saved data */
125 data->cregs[LTC4245_GPIO] = gpio_reg;
126}
127
128static struct ltc4245_data *ltc4245_update_device(struct device *dev)
129{
130 struct ltc4245_data *data = dev_get_drvdata(dev);
131 struct i2c_client *client = data->client;
132 s32 val;
133 int i;
134
135 mutex_lock(&data->update_lock);
136
137 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
138
139 /* Read control registers -- 0x00 to 0x07 */
140 for (i = 0; i < ARRAY_SIZE(data->cregs); i++) {
141 val = i2c_smbus_read_byte_data(client, i);
142 if (unlikely(val < 0))
143 data->cregs[i] = 0;
144 else
145 data->cregs[i] = val;
146 }
147
148 /* Read voltage registers -- 0x10 to 0x1c */
149 for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
150 val = i2c_smbus_read_byte_data(client, i+0x10);
151 if (unlikely(val < 0))
152 data->vregs[i] = 0;
153 else
154 data->vregs[i] = val;
155 }
156
157 /* Update GPIO readings */
158 ltc4245_update_gpios(dev);
159
160 data->last_updated = jiffies;
161 data->valid = true;
162 }
163
164 mutex_unlock(&data->update_lock);
165
166 return data;
167}
168
169/* Return the voltage from the given register in millivolts */
170static int ltc4245_get_voltage(struct device *dev, u8 reg)
171{
172 struct ltc4245_data *data = ltc4245_update_device(dev);
173 const u8 regval = data->vregs[reg - 0x10];
174 u32 voltage = 0;
175
176 switch (reg) {
177 case LTC4245_12VIN:
178 case LTC4245_12VOUT:
179 voltage = regval * 55;
180 break;
181 case LTC4245_5VIN:
182 case LTC4245_5VOUT:
183 voltage = regval * 22;
184 break;
185 case LTC4245_3VIN:
186 case LTC4245_3VOUT:
187 voltage = regval * 15;
188 break;
189 case LTC4245_VEEIN:
190 case LTC4245_VEEOUT:
191 voltage = regval * -55;
192 break;
193 case LTC4245_GPIOADC:
194 voltage = regval * 10;
195 break;
196 default:
197 /* If we get here, the developer messed up */
198 WARN_ON_ONCE(1);
199 break;
200 }
201
202 return voltage;
203}
204
205/* Return the current in the given sense register in milliAmperes */
206static unsigned int ltc4245_get_current(struct device *dev, u8 reg)
207{
208 struct ltc4245_data *data = ltc4245_update_device(dev);
209 const u8 regval = data->vregs[reg - 0x10];
210 unsigned int voltage;
211 unsigned int curr;
212
213 /*
214 * The strange looking conversions that follow are fixed-point
215 * math, since we cannot do floating point in the kernel.
216 *
217 * Step 1: convert sense register to microVolts
218 * Step 2: convert voltage to milliAmperes
219 *
220 * If you play around with the V=IR equation, you come up with
221 * the following: X uV / Y mOhm == Z mA
222 *
223 * With the resistors that are fractions of a milliOhm, we multiply
224 * the voltage and resistance by 10, to shift the decimal point.
225 * Now we can use the normal division operator again.
226 */
227
228 switch (reg) {
229 case LTC4245_12VSENSE:
230 voltage = regval * 250; /* voltage in uV */
231 curr = voltage / 50; /* sense resistor 50 mOhm */
232 break;
233 case LTC4245_5VSENSE:
234 voltage = regval * 125; /* voltage in uV */
235 curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */
236 break;
237 case LTC4245_3VSENSE:
238 voltage = regval * 125; /* voltage in uV */
239 curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */
240 break;
241 case LTC4245_VEESENSE:
242 voltage = regval * 250; /* voltage in uV */
243 curr = voltage / 100; /* sense resistor 100 mOhm */
244 break;
245 default:
246 /* If we get here, the developer messed up */
247 WARN_ON_ONCE(1);
248 curr = 0;
249 break;
250 }
251
252 return curr;
253}
254
255/* Map from voltage channel index to voltage register */
256
257static const s8 ltc4245_in_regs[] = {
258 LTC4245_12VIN, LTC4245_5VIN, LTC4245_3VIN, LTC4245_VEEIN,
259 LTC4245_12VOUT, LTC4245_5VOUT, LTC4245_3VOUT, LTC4245_VEEOUT,
260};
261
262/* Map from current channel index to current register */
263
264static const s8 ltc4245_curr_regs[] = {
265 LTC4245_12VSENSE, LTC4245_5VSENSE, LTC4245_3VSENSE, LTC4245_VEESENSE,
266};
267
268static int ltc4245_read_curr(struct device *dev, u32 attr, int channel,
269 long *val)
270{
271 struct ltc4245_data *data = ltc4245_update_device(dev);
272
273 switch (attr) {
274 case hwmon_curr_input:
275 *val = ltc4245_get_current(dev, ltc4245_curr_regs[channel]);
276 return 0;
277 case hwmon_curr_max_alarm:
278 *val = !!(data->cregs[LTC4245_FAULT1] & BIT(channel + 4));
279 return 0;
280 default:
281 return -EOPNOTSUPP;
282 }
283}
284
285static int ltc4245_read_in(struct device *dev, u32 attr, int channel, long *val)
286{
287 struct ltc4245_data *data = ltc4245_update_device(dev);
288
289 switch (attr) {
290 case hwmon_in_input:
291 if (channel < 8) {
292 *val = ltc4245_get_voltage(dev,
293 ltc4245_in_regs[channel]);
294 } else {
295 int regval = data->gpios[channel - 8];
296
297 if (regval < 0)
298 return regval;
299 *val = regval * 10;
300 }
301 return 0;
302 case hwmon_in_min_alarm:
303 if (channel < 4)
304 *val = !!(data->cregs[LTC4245_FAULT1] & BIT(channel));
305 else
306 *val = !!(data->cregs[LTC4245_FAULT2] &
307 BIT(channel - 4));
308 return 0;
309 default:
310 return -EOPNOTSUPP;
311 }
312}
313
314static int ltc4245_read_power(struct device *dev, u32 attr, int channel,
315 long *val)
316{
317 unsigned long curr;
318 long voltage;
319
320 switch (attr) {
321 case hwmon_power_input:
322 (void)ltc4245_update_device(dev);
323 curr = ltc4245_get_current(dev, ltc4245_curr_regs[channel]);
324 voltage = ltc4245_get_voltage(dev, ltc4245_in_regs[channel]);
325 *val = abs(curr * voltage);
326 return 0;
327 default:
328 return -EOPNOTSUPP;
329 }
330}
331
332static int ltc4245_read(struct device *dev, enum hwmon_sensor_types type,
333 u32 attr, int channel, long *val)
334{
335
336 switch (type) {
337 case hwmon_curr:
338 return ltc4245_read_curr(dev, attr, channel, val);
339 case hwmon_power:
340 return ltc4245_read_power(dev, attr, channel, val);
341 case hwmon_in:
342 return ltc4245_read_in(dev, attr, channel - 1, val);
343 default:
344 return -EOPNOTSUPP;
345 }
346}
347
348static umode_t ltc4245_is_visible(const void *_data,
349 enum hwmon_sensor_types type,
350 u32 attr, int channel)
351{
352 const struct ltc4245_data *data = _data;
353
354 switch (type) {
355 case hwmon_in:
356 if (channel == 0)
357 return 0;
358 switch (attr) {
359 case hwmon_in_input:
360 if (channel > 9 && !data->use_extra_gpios)
361 return 0;
362 return 0444;
363 case hwmon_in_min_alarm:
364 if (channel > 8)
365 return 0;
366 return 0444;
367 default:
368 return 0;
369 }
370 case hwmon_curr:
371 switch (attr) {
372 case hwmon_curr_input:
373 case hwmon_curr_max_alarm:
374 return 0444;
375 default:
376 return 0;
377 }
378 case hwmon_power:
379 switch (attr) {
380 case hwmon_power_input:
381 return 0444;
382 default:
383 return 0;
384 }
385 default:
386 return 0;
387 }
388}
389
390static const struct hwmon_channel_info *ltc4245_info[] = {
391 HWMON_CHANNEL_INFO(in,
392 HWMON_I_INPUT,
393 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
394 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
395 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
396 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
397 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
398 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
399 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
400 HWMON_I_INPUT | HWMON_I_MIN_ALARM,
401 HWMON_I_INPUT,
402 HWMON_I_INPUT,
403 HWMON_I_INPUT),
404 HWMON_CHANNEL_INFO(curr,
405 HWMON_C_INPUT | HWMON_C_MAX_ALARM,
406 HWMON_C_INPUT | HWMON_C_MAX_ALARM,
407 HWMON_C_INPUT | HWMON_C_MAX_ALARM,
408 HWMON_C_INPUT | HWMON_C_MAX_ALARM),
409 HWMON_CHANNEL_INFO(power,
410 HWMON_P_INPUT,
411 HWMON_P_INPUT,
412 HWMON_P_INPUT,
413 HWMON_P_INPUT),
414 NULL
415};
416
417static const struct hwmon_ops ltc4245_hwmon_ops = {
418 .is_visible = ltc4245_is_visible,
419 .read = ltc4245_read,
420};
421
422static const struct hwmon_chip_info ltc4245_chip_info = {
423 .ops = <c4245_hwmon_ops,
424 .info = ltc4245_info,
425};
426
427static bool ltc4245_use_extra_gpios(struct i2c_client *client)
428{
429 struct ltc4245_platform_data *pdata = dev_get_platdata(&client->dev);
430 struct device_node *np = client->dev.of_node;
431
432 /* prefer platform data */
433 if (pdata)
434 return pdata->use_extra_gpios;
435
436 /* fallback on OF */
437 if (of_find_property(np, "ltc4245,use-extra-gpios", NULL))
438 return true;
439
440 return false;
441}
442
443static int ltc4245_probe(struct i2c_client *client,
444 const struct i2c_device_id *id)
445{
446 struct i2c_adapter *adapter = client->adapter;
447 struct ltc4245_data *data;
448 struct device *hwmon_dev;
449
450 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
451 return -ENODEV;
452
453 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
454 if (!data)
455 return -ENOMEM;
456
457 data->client = client;
458 mutex_init(&data->update_lock);
459 data->use_extra_gpios = ltc4245_use_extra_gpios(client);
460
461 /* Initialize the LTC4245 chip */
462 i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00);
463 i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00);
464
465 hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
466 client->name, data,
467 <c4245_chip_info,
468 NULL);
469 return PTR_ERR_OR_ZERO(hwmon_dev);
470}
471
472static const struct i2c_device_id ltc4245_id[] = {
473 { "ltc4245", 0 },
474 { }
475};
476MODULE_DEVICE_TABLE(i2c, ltc4245_id);
477
478/* This is the driver that will be inserted */
479static struct i2c_driver ltc4245_driver = {
480 .driver = {
481 .name = "ltc4245",
482 },
483 .probe = ltc4245_probe,
484 .id_table = ltc4245_id,
485};
486
487module_i2c_driver(ltc4245_driver);
488
489MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
490MODULE_DESCRIPTION("LTC4245 driver");
491MODULE_LICENSE("GPL");
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#include <linux/jiffies.h>
25#include <linux/i2c/ltc4245.h>
26
27/* Here are names of the chip's registers (a.k.a. commands) */
28enum 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,
50 LTC4245_GPIOADC = 0x1c,
51};
52
53struct ltc4245_data {
54 struct i2c_client *client;
55
56 const struct attribute_group *groups[3];
57
58 struct mutex update_lock;
59 bool valid;
60 unsigned long last_updated; /* in jiffies */
61
62 /* Control registers */
63 u8 cregs[0x08];
64
65 /* Voltage registers */
66 u8 vregs[0x0d];
67
68 /* GPIO ADC registers */
69 bool use_extra_gpios;
70 int gpios[3];
71};
72
73/*
74 * Update the readings from the GPIO pins. If the driver has been configured to
75 * sample all GPIO's as analog voltages, a round-robin sampling method is used.
76 * Otherwise, only the configured GPIO pin is sampled.
77 *
78 * LOCKING: must hold data->update_lock
79 */
80static void ltc4245_update_gpios(struct device *dev)
81{
82 struct ltc4245_data *data = dev_get_drvdata(dev);
83 struct i2c_client *client = data->client;
84 u8 gpio_curr, gpio_next, gpio_reg;
85 int i;
86
87 /* no extra gpio support, we're basically done */
88 if (!data->use_extra_gpios) {
89 data->gpios[0] = data->vregs[LTC4245_GPIOADC - 0x10];
90 return;
91 }
92
93 /*
94 * If the last reading was too long ago, then we mark all old GPIO
95 * readings as stale by setting them to -EAGAIN
96 */
97 if (time_after(jiffies, data->last_updated + 5 * HZ)) {
98 for (i = 0; i < ARRAY_SIZE(data->gpios); i++)
99 data->gpios[i] = -EAGAIN;
100 }
101
102 /*
103 * Get the current GPIO pin
104 *
105 * The datasheet calls these GPIO[1-3], but we'll calculate the zero
106 * based array index instead, and call them GPIO[0-2]. This is much
107 * easier to think about.
108 */
109 gpio_curr = (data->cregs[LTC4245_GPIO] & 0xc0) >> 6;
110 if (gpio_curr > 0)
111 gpio_curr -= 1;
112
113 /* Read the GPIO voltage from the GPIOADC register */
114 data->gpios[gpio_curr] = data->vregs[LTC4245_GPIOADC - 0x10];
115
116 /* Find the next GPIO pin to read */
117 gpio_next = (gpio_curr + 1) % ARRAY_SIZE(data->gpios);
118
119 /*
120 * Calculate the correct setting for the GPIO register so it will
121 * sample the next GPIO pin
122 */
123 gpio_reg = (data->cregs[LTC4245_GPIO] & 0x3f) | ((gpio_next + 1) << 6);
124
125 /* Update the GPIO register */
126 i2c_smbus_write_byte_data(client, LTC4245_GPIO, gpio_reg);
127
128 /* Update saved data */
129 data->cregs[LTC4245_GPIO] = gpio_reg;
130}
131
132static struct ltc4245_data *ltc4245_update_device(struct device *dev)
133{
134 struct ltc4245_data *data = dev_get_drvdata(dev);
135 struct i2c_client *client = data->client;
136 s32 val;
137 int i;
138
139 mutex_lock(&data->update_lock);
140
141 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
142
143 /* Read control registers -- 0x00 to 0x07 */
144 for (i = 0; i < ARRAY_SIZE(data->cregs); i++) {
145 val = i2c_smbus_read_byte_data(client, i);
146 if (unlikely(val < 0))
147 data->cregs[i] = 0;
148 else
149 data->cregs[i] = val;
150 }
151
152 /* Read voltage registers -- 0x10 to 0x1c */
153 for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
154 val = i2c_smbus_read_byte_data(client, i+0x10);
155 if (unlikely(val < 0))
156 data->vregs[i] = 0;
157 else
158 data->vregs[i] = val;
159 }
160
161 /* Update GPIO readings */
162 ltc4245_update_gpios(dev);
163
164 data->last_updated = jiffies;
165 data->valid = 1;
166 }
167
168 mutex_unlock(&data->update_lock);
169
170 return data;
171}
172
173/* Return the voltage from the given register in millivolts */
174static int ltc4245_get_voltage(struct device *dev, u8 reg)
175{
176 struct ltc4245_data *data = ltc4245_update_device(dev);
177 const u8 regval = data->vregs[reg - 0x10];
178 u32 voltage = 0;
179
180 switch (reg) {
181 case LTC4245_12VIN:
182 case LTC4245_12VOUT:
183 voltage = regval * 55;
184 break;
185 case LTC4245_5VIN:
186 case LTC4245_5VOUT:
187 voltage = regval * 22;
188 break;
189 case LTC4245_3VIN:
190 case LTC4245_3VOUT:
191 voltage = regval * 15;
192 break;
193 case LTC4245_VEEIN:
194 case LTC4245_VEEOUT:
195 voltage = regval * -55;
196 break;
197 case LTC4245_GPIOADC:
198 voltage = regval * 10;
199 break;
200 default:
201 /* If we get here, the developer messed up */
202 WARN_ON_ONCE(1);
203 break;
204 }
205
206 return voltage;
207}
208
209/* Return the current in the given sense register in milliAmperes */
210static unsigned int ltc4245_get_current(struct device *dev, u8 reg)
211{
212 struct ltc4245_data *data = ltc4245_update_device(dev);
213 const u8 regval = data->vregs[reg - 0x10];
214 unsigned int voltage;
215 unsigned int curr;
216
217 /*
218 * The strange looking conversions that follow are fixed-point
219 * math, since we cannot do floating point in the kernel.
220 *
221 * Step 1: convert sense register to microVolts
222 * Step 2: convert voltage to milliAmperes
223 *
224 * If you play around with the V=IR equation, you come up with
225 * the following: X uV / Y mOhm == Z mA
226 *
227 * With the resistors that are fractions of a milliOhm, we multiply
228 * the voltage and resistance by 10, to shift the decimal point.
229 * Now we can use the normal division operator again.
230 */
231
232 switch (reg) {
233 case LTC4245_12VSENSE:
234 voltage = regval * 250; /* voltage in uV */
235 curr = voltage / 50; /* sense resistor 50 mOhm */
236 break;
237 case LTC4245_5VSENSE:
238 voltage = regval * 125; /* voltage in uV */
239 curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */
240 break;
241 case LTC4245_3VSENSE:
242 voltage = regval * 125; /* voltage in uV */
243 curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */
244 break;
245 case LTC4245_VEESENSE:
246 voltage = regval * 250; /* voltage in uV */
247 curr = voltage / 100; /* sense resistor 100 mOhm */
248 break;
249 default:
250 /* If we get here, the developer messed up */
251 WARN_ON_ONCE(1);
252 curr = 0;
253 break;
254 }
255
256 return curr;
257}
258
259static ssize_t ltc4245_show_voltage(struct device *dev,
260 struct device_attribute *da,
261 char *buf)
262{
263 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
264 const int voltage = ltc4245_get_voltage(dev, attr->index);
265
266 return snprintf(buf, PAGE_SIZE, "%d\n", voltage);
267}
268
269static ssize_t ltc4245_show_current(struct device *dev,
270 struct device_attribute *da,
271 char *buf)
272{
273 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
274 const unsigned int curr = ltc4245_get_current(dev, attr->index);
275
276 return snprintf(buf, PAGE_SIZE, "%u\n", curr);
277}
278
279static ssize_t ltc4245_show_power(struct device *dev,
280 struct device_attribute *da,
281 char *buf)
282{
283 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
284 const unsigned int curr = ltc4245_get_current(dev, attr->index);
285 const int output_voltage = ltc4245_get_voltage(dev, attr->index+1);
286
287 /* current in mA * voltage in mV == power in uW */
288 const unsigned int power = abs(output_voltage * curr);
289
290 return snprintf(buf, PAGE_SIZE, "%u\n", power);
291}
292
293static ssize_t ltc4245_show_alarm(struct device *dev,
294 struct device_attribute *da,
295 char *buf)
296{
297 struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
298 struct ltc4245_data *data = ltc4245_update_device(dev);
299 const u8 reg = data->cregs[attr->index];
300 const u32 mask = attr->nr;
301
302 return snprintf(buf, PAGE_SIZE, "%u\n", (reg & mask) ? 1 : 0);
303}
304
305static ssize_t ltc4245_show_gpio(struct device *dev,
306 struct device_attribute *da,
307 char *buf)
308{
309 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
310 struct ltc4245_data *data = ltc4245_update_device(dev);
311 int val = data->gpios[attr->index];
312
313 /* handle stale GPIO's */
314 if (val < 0)
315 return val;
316
317 /* Convert to millivolts and print */
318 return snprintf(buf, PAGE_SIZE, "%u\n", val * 10);
319}
320
321/* Construct a sensor_device_attribute structure for each register */
322
323/* Input voltages */
324static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4245_show_voltage, NULL,
325 LTC4245_12VIN);
326static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4245_show_voltage, NULL,
327 LTC4245_5VIN);
328static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc4245_show_voltage, NULL,
329 LTC4245_3VIN);
330static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc4245_show_voltage, NULL,
331 LTC4245_VEEIN);
332
333/* Input undervoltage alarms */
334static SENSOR_DEVICE_ATTR_2(in1_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
335 1 << 0, LTC4245_FAULT1);
336static SENSOR_DEVICE_ATTR_2(in2_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
337 1 << 1, LTC4245_FAULT1);
338static SENSOR_DEVICE_ATTR_2(in3_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
339 1 << 2, LTC4245_FAULT1);
340static SENSOR_DEVICE_ATTR_2(in4_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
341 1 << 3, LTC4245_FAULT1);
342
343/* Currents (via sense resistor) */
344static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4245_show_current, NULL,
345 LTC4245_12VSENSE);
346static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc4245_show_current, NULL,
347 LTC4245_5VSENSE);
348static SENSOR_DEVICE_ATTR(curr3_input, S_IRUGO, ltc4245_show_current, NULL,
349 LTC4245_3VSENSE);
350static SENSOR_DEVICE_ATTR(curr4_input, S_IRUGO, ltc4245_show_current, NULL,
351 LTC4245_VEESENSE);
352
353/* Overcurrent alarms */
354static SENSOR_DEVICE_ATTR_2(curr1_max_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
355 1 << 4, LTC4245_FAULT1);
356static SENSOR_DEVICE_ATTR_2(curr2_max_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
357 1 << 5, LTC4245_FAULT1);
358static SENSOR_DEVICE_ATTR_2(curr3_max_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
359 1 << 6, LTC4245_FAULT1);
360static SENSOR_DEVICE_ATTR_2(curr4_max_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
361 1 << 7, LTC4245_FAULT1);
362
363/* Output voltages */
364static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ltc4245_show_voltage, NULL,
365 LTC4245_12VOUT);
366static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, ltc4245_show_voltage, NULL,
367 LTC4245_5VOUT);
368static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, ltc4245_show_voltage, NULL,
369 LTC4245_3VOUT);
370static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, ltc4245_show_voltage, NULL,
371 LTC4245_VEEOUT);
372
373/* Power Bad alarms */
374static SENSOR_DEVICE_ATTR_2(in5_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
375 1 << 0, LTC4245_FAULT2);
376static SENSOR_DEVICE_ATTR_2(in6_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
377 1 << 1, LTC4245_FAULT2);
378static SENSOR_DEVICE_ATTR_2(in7_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
379 1 << 2, LTC4245_FAULT2);
380static SENSOR_DEVICE_ATTR_2(in8_min_alarm, S_IRUGO, ltc4245_show_alarm, NULL,
381 1 << 3, LTC4245_FAULT2);
382
383/* GPIO voltages */
384static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, ltc4245_show_gpio, NULL, 0);
385static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, ltc4245_show_gpio, NULL, 1);
386static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, ltc4245_show_gpio, NULL, 2);
387
388/* Power Consumption (virtual) */
389static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ltc4245_show_power, NULL,
390 LTC4245_12VSENSE);
391static SENSOR_DEVICE_ATTR(power2_input, S_IRUGO, ltc4245_show_power, NULL,
392 LTC4245_5VSENSE);
393static SENSOR_DEVICE_ATTR(power3_input, S_IRUGO, ltc4245_show_power, NULL,
394 LTC4245_3VSENSE);
395static SENSOR_DEVICE_ATTR(power4_input, S_IRUGO, ltc4245_show_power, NULL,
396 LTC4245_VEESENSE);
397
398/*
399 * Finally, construct an array of pointers to members of the above objects,
400 * as required for sysfs_create_group()
401 */
402static struct attribute *ltc4245_std_attributes[] = {
403 &sensor_dev_attr_in1_input.dev_attr.attr,
404 &sensor_dev_attr_in2_input.dev_attr.attr,
405 &sensor_dev_attr_in3_input.dev_attr.attr,
406 &sensor_dev_attr_in4_input.dev_attr.attr,
407
408 &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
409 &sensor_dev_attr_in2_min_alarm.dev_attr.attr,
410 &sensor_dev_attr_in3_min_alarm.dev_attr.attr,
411 &sensor_dev_attr_in4_min_alarm.dev_attr.attr,
412
413 &sensor_dev_attr_curr1_input.dev_attr.attr,
414 &sensor_dev_attr_curr2_input.dev_attr.attr,
415 &sensor_dev_attr_curr3_input.dev_attr.attr,
416 &sensor_dev_attr_curr4_input.dev_attr.attr,
417
418 &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
419 &sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
420 &sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
421 &sensor_dev_attr_curr4_max_alarm.dev_attr.attr,
422
423 &sensor_dev_attr_in5_input.dev_attr.attr,
424 &sensor_dev_attr_in6_input.dev_attr.attr,
425 &sensor_dev_attr_in7_input.dev_attr.attr,
426 &sensor_dev_attr_in8_input.dev_attr.attr,
427
428 &sensor_dev_attr_in5_min_alarm.dev_attr.attr,
429 &sensor_dev_attr_in6_min_alarm.dev_attr.attr,
430 &sensor_dev_attr_in7_min_alarm.dev_attr.attr,
431 &sensor_dev_attr_in8_min_alarm.dev_attr.attr,
432
433 &sensor_dev_attr_in9_input.dev_attr.attr,
434
435 &sensor_dev_attr_power1_input.dev_attr.attr,
436 &sensor_dev_attr_power2_input.dev_attr.attr,
437 &sensor_dev_attr_power3_input.dev_attr.attr,
438 &sensor_dev_attr_power4_input.dev_attr.attr,
439
440 NULL,
441};
442
443static struct attribute *ltc4245_gpio_attributes[] = {
444 &sensor_dev_attr_in10_input.dev_attr.attr,
445 &sensor_dev_attr_in11_input.dev_attr.attr,
446 NULL,
447};
448
449static const struct attribute_group ltc4245_std_group = {
450 .attrs = ltc4245_std_attributes,
451};
452
453static const struct attribute_group ltc4245_gpio_group = {
454 .attrs = ltc4245_gpio_attributes,
455};
456
457static void ltc4245_sysfs_add_groups(struct ltc4245_data *data)
458{
459 /* standard sysfs attributes */
460 data->groups[0] = <c4245_std_group;
461
462 /* if we're using the extra gpio support, register it's attributes */
463 if (data->use_extra_gpios)
464 data->groups[1] = <c4245_gpio_group;
465}
466
467static bool ltc4245_use_extra_gpios(struct i2c_client *client)
468{
469 struct ltc4245_platform_data *pdata = dev_get_platdata(&client->dev);
470 struct device_node *np = client->dev.of_node;
471
472 /* prefer platform data */
473 if (pdata)
474 return pdata->use_extra_gpios;
475
476 /* fallback on OF */
477 if (of_find_property(np, "ltc4245,use-extra-gpios", NULL))
478 return true;
479
480 return false;
481}
482
483static int ltc4245_probe(struct i2c_client *client,
484 const struct i2c_device_id *id)
485{
486 struct i2c_adapter *adapter = client->adapter;
487 struct ltc4245_data *data;
488 struct device *hwmon_dev;
489
490 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
491 return -ENODEV;
492
493 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
494 if (!data)
495 return -ENOMEM;
496
497 data->client = client;
498 mutex_init(&data->update_lock);
499 data->use_extra_gpios = ltc4245_use_extra_gpios(client);
500
501 /* Initialize the LTC4245 chip */
502 i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00);
503 i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00);
504
505 /* Add sysfs hooks */
506 ltc4245_sysfs_add_groups(data);
507
508 hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
509 client->name, data,
510 data->groups);
511 return PTR_ERR_OR_ZERO(hwmon_dev);
512}
513
514static const struct i2c_device_id ltc4245_id[] = {
515 { "ltc4245", 0 },
516 { }
517};
518MODULE_DEVICE_TABLE(i2c, ltc4245_id);
519
520/* This is the driver that will be inserted */
521static struct i2c_driver ltc4245_driver = {
522 .driver = {
523 .name = "ltc4245",
524 },
525 .probe = ltc4245_probe,
526 .id_table = ltc4245_id,
527};
528
529module_i2c_driver(ltc4245_driver);
530
531MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
532MODULE_DESCRIPTION("LTC4245 driver");
533MODULE_LICENSE("GPL");