1/*
2 * powr1220.c - Driver for the Lattice POWR1220 programmable power supply
3 * and monitor. Users can read all ADC inputs along with their labels
4 * using the sysfs nodes.
5 *
6 * Copyright (c) 2014 Echo360 http://www.echo360.com
7 * Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 */
19
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/slab.h>
23#include <linux/jiffies.h>
24#include <linux/i2c.h>
25#include <linux/hwmon.h>
26#include <linux/hwmon-sysfs.h>
27#include <linux/err.h>
28#include <linux/mutex.h>
29#include <linux/delay.h>
30
31#define ADC_STEP_MV			2
32#define ADC_MAX_LOW_MEASUREMENT_MV	2000
33
34enum powr1220_regs {
35	VMON_STATUS0,
36	VMON_STATUS1,
37	VMON_STATUS2,
38	OUTPUT_STATUS0,
39	OUTPUT_STATUS1,
40	OUTPUT_STATUS2,
41	INPUT_STATUS,
42	ADC_VALUE_LOW,
43	ADC_VALUE_HIGH,
44	ADC_MUX,
45	UES_BYTE0,
46	UES_BYTE1,
47	UES_BYTE2,
48	UES_BYTE3,
49	GP_OUTPUT1,
50	GP_OUTPUT2,
51	GP_OUTPUT3,
52	INPUT_VALUE,
53	RESET,
54	TRIM1_TRIM,
55	TRIM2_TRIM,
56	TRIM3_TRIM,
57	TRIM4_TRIM,
58	TRIM5_TRIM,
59	TRIM6_TRIM,
60	TRIM7_TRIM,
61	TRIM8_TRIM,
62	MAX_POWR1220_REGS
63};
64
65enum powr1220_adc_values {
66	VMON1,
67	VMON2,
68	VMON3,
69	VMON4,
70	VMON5,
71	VMON6,
72	VMON7,
73	VMON8,
74	VMON9,
75	VMON10,
76	VMON11,
77	VMON12,
78	VCCA,
79	VCCINP,
80	MAX_POWR1220_ADC_VALUES
81};
82
83struct powr1220_data {
84	struct i2c_client *client;
85	struct mutex update_lock;
86	bool adc_valid[MAX_POWR1220_ADC_VALUES];
87	 /* the next value is in jiffies */
88	unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
89
90	/* values */
91	int adc_maxes[MAX_POWR1220_ADC_VALUES];
92	int adc_values[MAX_POWR1220_ADC_VALUES];
93};
94
95static const char * const input_names[] = {
96	[VMON1]    = "vmon1",
97	[VMON2]    = "vmon2",
98	[VMON3]    = "vmon3",
99	[VMON4]    = "vmon4",
100	[VMON5]    = "vmon5",
101	[VMON6]    = "vmon6",
102	[VMON7]    = "vmon7",
103	[VMON8]    = "vmon8",
104	[VMON9]    = "vmon9",
105	[VMON10]   = "vmon10",
106	[VMON11]   = "vmon11",
107	[VMON12]   = "vmon12",
108	[VCCA]     = "vcca",
109	[VCCINP]   = "vccinp",
110};
111
112/* Reads the specified ADC channel */
113static int powr1220_read_adc(struct device *dev, int ch_num)
114{
115	struct powr1220_data *data = dev_get_drvdata(dev);
116	int reading;
117	int result;
118	int adc_range = 0;
119
120	mutex_lock(&data->update_lock);
121
122	if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
123			!data->adc_valid[ch_num]) {
124		/*
125		 * figure out if we need to use the attenuator for
126		 * high inputs or inputs that we don't yet have a measurement
127		 * for. We dynamically set the attenuator depending on the
128		 * max reading.
129		 */
130		if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
131				data->adc_maxes[ch_num] == 0)
132			adc_range = 1 << 4;
133
134		/* set the attenuator and mux */
135		result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
136				adc_range | ch_num);
137		if (result)
138			goto exit;
139
140		/*
141		 * wait at least Tconvert time (200 us) for the
142		 * conversion to complete
143		 */
144		udelay(200);
145
146		/* get the ADC reading */
147		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
148		if (result < 0)
149			goto exit;
150
151		reading = result >> 4;
152
153		/* get the upper half of the reading */
154		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
155		if (result < 0)
156			goto exit;
157
158		reading |= result << 4;
159
160		/* now convert the reading to a voltage */
161		reading *= ADC_STEP_MV;
162		data->adc_values[ch_num] = reading;
163		data->adc_valid[ch_num] = true;
164		data->adc_last_updated[ch_num] = jiffies;
165		result = reading;
166
167		if (reading > data->adc_maxes[ch_num])
168			data->adc_maxes[ch_num] = reading;
169	} else {
170		result = data->adc_values[ch_num];
171	}
172
173exit:
174	mutex_unlock(&data->update_lock);
175
176	return result;
177}
178
179/* Shows the voltage associated with the specified ADC channel */
180static ssize_t powr1220_show_voltage(struct device *dev,
181	struct device_attribute *dev_attr, char *buf)
182{
183	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
184	int adc_val = powr1220_read_adc(dev, attr->index);
185
186	if (adc_val < 0)
187		return adc_val;
188
189	return sprintf(buf, "%d\n", adc_val);
190}
191
192/* Shows the maximum setting associated with the specified ADC channel */
193static ssize_t powr1220_show_max(struct device *dev,
194	struct device_attribute *dev_attr, char *buf)
195{
196	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
197	struct powr1220_data *data = dev_get_drvdata(dev);
198
199	return sprintf(buf, "%d\n", data->adc_maxes[attr->index]);
200}
201
202/* Shows the label associated with the specified ADC channel */
203static ssize_t powr1220_show_label(struct device *dev,
204	struct device_attribute *dev_attr, char *buf)
205{
206	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
207
208	return sprintf(buf, "%s\n", input_names[attr->index]);
209}
210
211static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, powr1220_show_voltage, NULL,
212	VMON1);
213static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, powr1220_show_voltage, NULL,
214	VMON2);
215static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, powr1220_show_voltage, NULL,
216	VMON3);
217static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, powr1220_show_voltage, NULL,
218	VMON4);
219static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, powr1220_show_voltage, NULL,
220	VMON5);
221static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, powr1220_show_voltage, NULL,
222	VMON6);
223static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, powr1220_show_voltage, NULL,
224	VMON7);
225static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, powr1220_show_voltage, NULL,
226	VMON8);
227static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, powr1220_show_voltage, NULL,
228	VMON9);
229static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, powr1220_show_voltage, NULL,
230	VMON10);
231static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, powr1220_show_voltage, NULL,
232	VMON11);
233static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, powr1220_show_voltage, NULL,
234	VMON12);
235static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, powr1220_show_voltage, NULL,
236	VCCA);
237static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, powr1220_show_voltage, NULL,
238	VCCINP);
239
240static SENSOR_DEVICE_ATTR(in0_highest, S_IRUGO, powr1220_show_max, NULL,
241	VMON1);
242static SENSOR_DEVICE_ATTR(in1_highest, S_IRUGO, powr1220_show_max, NULL,
243	VMON2);
244static SENSOR_DEVICE_ATTR(in2_highest, S_IRUGO, powr1220_show_max, NULL,
245	VMON3);
246static SENSOR_DEVICE_ATTR(in3_highest, S_IRUGO, powr1220_show_max, NULL,
247	VMON4);
248static SENSOR_DEVICE_ATTR(in4_highest, S_IRUGO, powr1220_show_max, NULL,
249	VMON5);
250static SENSOR_DEVICE_ATTR(in5_highest, S_IRUGO, powr1220_show_max, NULL,
251	VMON6);
252static SENSOR_DEVICE_ATTR(in6_highest, S_IRUGO, powr1220_show_max, NULL,
253	VMON7);
254static SENSOR_DEVICE_ATTR(in7_highest, S_IRUGO, powr1220_show_max, NULL,
255	VMON8);
256static SENSOR_DEVICE_ATTR(in8_highest, S_IRUGO, powr1220_show_max, NULL,
257	VMON9);
258static SENSOR_DEVICE_ATTR(in9_highest, S_IRUGO, powr1220_show_max, NULL,
259	VMON10);
260static SENSOR_DEVICE_ATTR(in10_highest, S_IRUGO, powr1220_show_max, NULL,
261	VMON11);
262static SENSOR_DEVICE_ATTR(in11_highest, S_IRUGO, powr1220_show_max, NULL,
263	VMON12);
264static SENSOR_DEVICE_ATTR(in12_highest, S_IRUGO, powr1220_show_max, NULL,
265	VCCA);
266static SENSOR_DEVICE_ATTR(in13_highest, S_IRUGO, powr1220_show_max, NULL,
267	VCCINP);
268
269static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO, powr1220_show_label, NULL,
270	VMON1);
271static SENSOR_DEVICE_ATTR(in1_label, S_IRUGO, powr1220_show_label, NULL,
272	VMON2);
273static SENSOR_DEVICE_ATTR(in2_label, S_IRUGO, powr1220_show_label, NULL,
274	VMON3);
275static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, powr1220_show_label, NULL,
276	VMON4);
277static SENSOR_DEVICE_ATTR(in4_label, S_IRUGO, powr1220_show_label, NULL,
278	VMON5);
279static SENSOR_DEVICE_ATTR(in5_label, S_IRUGO, powr1220_show_label, NULL,
280	VMON6);
281static SENSOR_DEVICE_ATTR(in6_label, S_IRUGO, powr1220_show_label, NULL,
282	VMON7);
283static SENSOR_DEVICE_ATTR(in7_label, S_IRUGO, powr1220_show_label, NULL,
284	VMON8);
285static SENSOR_DEVICE_ATTR(in8_label, S_IRUGO, powr1220_show_label, NULL,
286	VMON9);
287static SENSOR_DEVICE_ATTR(in9_label, S_IRUGO, powr1220_show_label, NULL,
288	VMON10);
289static SENSOR_DEVICE_ATTR(in10_label, S_IRUGO, powr1220_show_label, NULL,
290	VMON11);
291static SENSOR_DEVICE_ATTR(in11_label, S_IRUGO, powr1220_show_label, NULL,
292	VMON12);
293static SENSOR_DEVICE_ATTR(in12_label, S_IRUGO, powr1220_show_label, NULL,
294	VCCA);
295static SENSOR_DEVICE_ATTR(in13_label, S_IRUGO, powr1220_show_label, NULL,
296	VCCINP);
297
298static struct attribute *powr1220_attrs[] = {
299	&sensor_dev_attr_in0_input.dev_attr.attr,
300	&sensor_dev_attr_in1_input.dev_attr.attr,
301	&sensor_dev_attr_in2_input.dev_attr.attr,
302	&sensor_dev_attr_in3_input.dev_attr.attr,
303	&sensor_dev_attr_in4_input.dev_attr.attr,
304	&sensor_dev_attr_in5_input.dev_attr.attr,
305	&sensor_dev_attr_in6_input.dev_attr.attr,
306	&sensor_dev_attr_in7_input.dev_attr.attr,
307	&sensor_dev_attr_in8_input.dev_attr.attr,
308	&sensor_dev_attr_in9_input.dev_attr.attr,
309	&sensor_dev_attr_in10_input.dev_attr.attr,
310	&sensor_dev_attr_in11_input.dev_attr.attr,
311	&sensor_dev_attr_in12_input.dev_attr.attr,
312	&sensor_dev_attr_in13_input.dev_attr.attr,
313
314	&sensor_dev_attr_in0_highest.dev_attr.attr,
315	&sensor_dev_attr_in1_highest.dev_attr.attr,
316	&sensor_dev_attr_in2_highest.dev_attr.attr,
317	&sensor_dev_attr_in3_highest.dev_attr.attr,
318	&sensor_dev_attr_in4_highest.dev_attr.attr,
319	&sensor_dev_attr_in5_highest.dev_attr.attr,
320	&sensor_dev_attr_in6_highest.dev_attr.attr,
321	&sensor_dev_attr_in7_highest.dev_attr.attr,
322	&sensor_dev_attr_in8_highest.dev_attr.attr,
323	&sensor_dev_attr_in9_highest.dev_attr.attr,
324	&sensor_dev_attr_in10_highest.dev_attr.attr,
325	&sensor_dev_attr_in11_highest.dev_attr.attr,
326	&sensor_dev_attr_in12_highest.dev_attr.attr,
327	&sensor_dev_attr_in13_highest.dev_attr.attr,
328
329	&sensor_dev_attr_in0_label.dev_attr.attr,
330	&sensor_dev_attr_in1_label.dev_attr.attr,
331	&sensor_dev_attr_in2_label.dev_attr.attr,
332	&sensor_dev_attr_in3_label.dev_attr.attr,
333	&sensor_dev_attr_in4_label.dev_attr.attr,
334	&sensor_dev_attr_in5_label.dev_attr.attr,
335	&sensor_dev_attr_in6_label.dev_attr.attr,
336	&sensor_dev_attr_in7_label.dev_attr.attr,
337	&sensor_dev_attr_in8_label.dev_attr.attr,
338	&sensor_dev_attr_in9_label.dev_attr.attr,
339	&sensor_dev_attr_in10_label.dev_attr.attr,
340	&sensor_dev_attr_in11_label.dev_attr.attr,
341	&sensor_dev_attr_in12_label.dev_attr.attr,
342	&sensor_dev_attr_in13_label.dev_attr.attr,
343
344	NULL
345};
346
347ATTRIBUTE_GROUPS(powr1220);
348
349static int powr1220_probe(struct i2c_client *client,
350		const struct i2c_device_id *id)
351{
352	struct powr1220_data *data;
353	struct device *hwmon_dev;
354
355	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
356		return -ENODEV;
357
358	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
359	if (!data)
360		return -ENOMEM;
361
362	mutex_init(&data->update_lock);
363	data->client = client;
364
365	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
366			client->name, data, powr1220_groups);
367
368	return PTR_ERR_OR_ZERO(hwmon_dev);
369}
370
371static const struct i2c_device_id powr1220_ids[] = {
372	{ "powr1220", 0, },
373	{ }
374};
375
376MODULE_DEVICE_TABLE(i2c, powr1220_ids);
377
378static struct i2c_driver powr1220_driver = {
379	.class		= I2C_CLASS_HWMON,
380	.driver = {
381		.name	= "powr1220",
382	},
383	.probe		= powr1220_probe,
384	.id_table	= powr1220_ids,
385};
386
387module_i2c_driver(powr1220_driver);
388
389MODULE_AUTHOR("Scott Kanowitz");
390MODULE_DESCRIPTION("POWR1220 driver");
391MODULE_LICENSE("GPL");
392