xref: /openbmc/linux/drivers/hwmon/powr1220.c (revision dbf563ee)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * powr1220.c - Driver for the Lattice POWR1220 programmable power supply
4  * and monitor. Users can read all ADC inputs along with their labels
5  * using the sysfs nodes.
6  *
7  * Copyright (c) 2014 Echo360 https://www.echo360.com
8  * Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/slab.h>
14 #include <linux/jiffies.h>
15 #include <linux/i2c.h>
16 #include <linux/hwmon.h>
17 #include <linux/hwmon-sysfs.h>
18 #include <linux/err.h>
19 #include <linux/mutex.h>
20 #include <linux/delay.h>
21 
22 #define ADC_STEP_MV			2
23 #define ADC_MAX_LOW_MEASUREMENT_MV	2000
24 
25 enum powr1220_regs {
26 	VMON_STATUS0,
27 	VMON_STATUS1,
28 	VMON_STATUS2,
29 	OUTPUT_STATUS0,
30 	OUTPUT_STATUS1,
31 	OUTPUT_STATUS2,
32 	INPUT_STATUS,
33 	ADC_VALUE_LOW,
34 	ADC_VALUE_HIGH,
35 	ADC_MUX,
36 	UES_BYTE0,
37 	UES_BYTE1,
38 	UES_BYTE2,
39 	UES_BYTE3,
40 	GP_OUTPUT1,
41 	GP_OUTPUT2,
42 	GP_OUTPUT3,
43 	INPUT_VALUE,
44 	RESET,
45 	TRIM1_TRIM,
46 	TRIM2_TRIM,
47 	TRIM3_TRIM,
48 	TRIM4_TRIM,
49 	TRIM5_TRIM,
50 	TRIM6_TRIM,
51 	TRIM7_TRIM,
52 	TRIM8_TRIM,
53 	MAX_POWR1220_REGS
54 };
55 
56 enum powr1220_adc_values {
57 	VMON1,
58 	VMON2,
59 	VMON3,
60 	VMON4,
61 	VMON5,
62 	VMON6,
63 	VMON7,
64 	VMON8,
65 	VMON9,
66 	VMON10,
67 	VMON11,
68 	VMON12,
69 	VCCA,
70 	VCCINP,
71 	MAX_POWR1220_ADC_VALUES
72 };
73 
74 struct powr1220_data {
75 	struct i2c_client *client;
76 	struct mutex update_lock;
77 	bool adc_valid[MAX_POWR1220_ADC_VALUES];
78 	 /* the next value is in jiffies */
79 	unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
80 
81 	/* values */
82 	int adc_maxes[MAX_POWR1220_ADC_VALUES];
83 	int adc_values[MAX_POWR1220_ADC_VALUES];
84 };
85 
86 static const char * const input_names[] = {
87 	[VMON1]    = "vmon1",
88 	[VMON2]    = "vmon2",
89 	[VMON3]    = "vmon3",
90 	[VMON4]    = "vmon4",
91 	[VMON5]    = "vmon5",
92 	[VMON6]    = "vmon6",
93 	[VMON7]    = "vmon7",
94 	[VMON8]    = "vmon8",
95 	[VMON9]    = "vmon9",
96 	[VMON10]   = "vmon10",
97 	[VMON11]   = "vmon11",
98 	[VMON12]   = "vmon12",
99 	[VCCA]     = "vcca",
100 	[VCCINP]   = "vccinp",
101 };
102 
103 /* Reads the specified ADC channel */
104 static int powr1220_read_adc(struct device *dev, int ch_num)
105 {
106 	struct powr1220_data *data = dev_get_drvdata(dev);
107 	int reading;
108 	int result;
109 	int adc_range = 0;
110 
111 	mutex_lock(&data->update_lock);
112 
113 	if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
114 			!data->adc_valid[ch_num]) {
115 		/*
116 		 * figure out if we need to use the attenuator for
117 		 * high inputs or inputs that we don't yet have a measurement
118 		 * for. We dynamically set the attenuator depending on the
119 		 * max reading.
120 		 */
121 		if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
122 				data->adc_maxes[ch_num] == 0)
123 			adc_range = 1 << 4;
124 
125 		/* set the attenuator and mux */
126 		result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
127 				adc_range | ch_num);
128 		if (result)
129 			goto exit;
130 
131 		/*
132 		 * wait at least Tconvert time (200 us) for the
133 		 * conversion to complete
134 		 */
135 		udelay(200);
136 
137 		/* get the ADC reading */
138 		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
139 		if (result < 0)
140 			goto exit;
141 
142 		reading = result >> 4;
143 
144 		/* get the upper half of the reading */
145 		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
146 		if (result < 0)
147 			goto exit;
148 
149 		reading |= result << 4;
150 
151 		/* now convert the reading to a voltage */
152 		reading *= ADC_STEP_MV;
153 		data->adc_values[ch_num] = reading;
154 		data->adc_valid[ch_num] = true;
155 		data->adc_last_updated[ch_num] = jiffies;
156 		result = reading;
157 
158 		if (reading > data->adc_maxes[ch_num])
159 			data->adc_maxes[ch_num] = reading;
160 	} else {
161 		result = data->adc_values[ch_num];
162 	}
163 
164 exit:
165 	mutex_unlock(&data->update_lock);
166 
167 	return result;
168 }
169 
170 /* Shows the voltage associated with the specified ADC channel */
171 static ssize_t powr1220_voltage_show(struct device *dev,
172 				     struct device_attribute *dev_attr,
173 				     char *buf)
174 {
175 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
176 	int adc_val = powr1220_read_adc(dev, attr->index);
177 
178 	if (adc_val < 0)
179 		return adc_val;
180 
181 	return sprintf(buf, "%d\n", adc_val);
182 }
183 
184 /* Shows the maximum setting associated with the specified ADC channel */
185 static ssize_t powr1220_max_show(struct device *dev,
186 				 struct device_attribute *dev_attr, char *buf)
187 {
188 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
189 	struct powr1220_data *data = dev_get_drvdata(dev);
190 
191 	return sprintf(buf, "%d\n", data->adc_maxes[attr->index]);
192 }
193 
194 /* Shows the label associated with the specified ADC channel */
195 static ssize_t powr1220_label_show(struct device *dev,
196 				   struct device_attribute *dev_attr,
197 				   char *buf)
198 {
199 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
200 
201 	return sprintf(buf, "%s\n", input_names[attr->index]);
202 }
203 
204 static SENSOR_DEVICE_ATTR_RO(in0_input, powr1220_voltage, VMON1);
205 static SENSOR_DEVICE_ATTR_RO(in1_input, powr1220_voltage, VMON2);
206 static SENSOR_DEVICE_ATTR_RO(in2_input, powr1220_voltage, VMON3);
207 static SENSOR_DEVICE_ATTR_RO(in3_input, powr1220_voltage, VMON4);
208 static SENSOR_DEVICE_ATTR_RO(in4_input, powr1220_voltage, VMON5);
209 static SENSOR_DEVICE_ATTR_RO(in5_input, powr1220_voltage, VMON6);
210 static SENSOR_DEVICE_ATTR_RO(in6_input, powr1220_voltage, VMON7);
211 static SENSOR_DEVICE_ATTR_RO(in7_input, powr1220_voltage, VMON8);
212 static SENSOR_DEVICE_ATTR_RO(in8_input, powr1220_voltage, VMON9);
213 static SENSOR_DEVICE_ATTR_RO(in9_input, powr1220_voltage, VMON10);
214 static SENSOR_DEVICE_ATTR_RO(in10_input, powr1220_voltage, VMON11);
215 static SENSOR_DEVICE_ATTR_RO(in11_input, powr1220_voltage, VMON12);
216 static SENSOR_DEVICE_ATTR_RO(in12_input, powr1220_voltage, VCCA);
217 static SENSOR_DEVICE_ATTR_RO(in13_input, powr1220_voltage, VCCINP);
218 
219 static SENSOR_DEVICE_ATTR_RO(in0_highest, powr1220_max, VMON1);
220 static SENSOR_DEVICE_ATTR_RO(in1_highest, powr1220_max, VMON2);
221 static SENSOR_DEVICE_ATTR_RO(in2_highest, powr1220_max, VMON3);
222 static SENSOR_DEVICE_ATTR_RO(in3_highest, powr1220_max, VMON4);
223 static SENSOR_DEVICE_ATTR_RO(in4_highest, powr1220_max, VMON5);
224 static SENSOR_DEVICE_ATTR_RO(in5_highest, powr1220_max, VMON6);
225 static SENSOR_DEVICE_ATTR_RO(in6_highest, powr1220_max, VMON7);
226 static SENSOR_DEVICE_ATTR_RO(in7_highest, powr1220_max, VMON8);
227 static SENSOR_DEVICE_ATTR_RO(in8_highest, powr1220_max, VMON9);
228 static SENSOR_DEVICE_ATTR_RO(in9_highest, powr1220_max, VMON10);
229 static SENSOR_DEVICE_ATTR_RO(in10_highest, powr1220_max, VMON11);
230 static SENSOR_DEVICE_ATTR_RO(in11_highest, powr1220_max, VMON12);
231 static SENSOR_DEVICE_ATTR_RO(in12_highest, powr1220_max, VCCA);
232 static SENSOR_DEVICE_ATTR_RO(in13_highest, powr1220_max, VCCINP);
233 
234 static SENSOR_DEVICE_ATTR_RO(in0_label, powr1220_label, VMON1);
235 static SENSOR_DEVICE_ATTR_RO(in1_label, powr1220_label, VMON2);
236 static SENSOR_DEVICE_ATTR_RO(in2_label, powr1220_label, VMON3);
237 static SENSOR_DEVICE_ATTR_RO(in3_label, powr1220_label, VMON4);
238 static SENSOR_DEVICE_ATTR_RO(in4_label, powr1220_label, VMON5);
239 static SENSOR_DEVICE_ATTR_RO(in5_label, powr1220_label, VMON6);
240 static SENSOR_DEVICE_ATTR_RO(in6_label, powr1220_label, VMON7);
241 static SENSOR_DEVICE_ATTR_RO(in7_label, powr1220_label, VMON8);
242 static SENSOR_DEVICE_ATTR_RO(in8_label, powr1220_label, VMON9);
243 static SENSOR_DEVICE_ATTR_RO(in9_label, powr1220_label, VMON10);
244 static SENSOR_DEVICE_ATTR_RO(in10_label, powr1220_label, VMON11);
245 static SENSOR_DEVICE_ATTR_RO(in11_label, powr1220_label, VMON12);
246 static SENSOR_DEVICE_ATTR_RO(in12_label, powr1220_label, VCCA);
247 static SENSOR_DEVICE_ATTR_RO(in13_label, powr1220_label, VCCINP);
248 
249 static struct attribute *powr1220_attrs[] = {
250 	&sensor_dev_attr_in0_input.dev_attr.attr,
251 	&sensor_dev_attr_in1_input.dev_attr.attr,
252 	&sensor_dev_attr_in2_input.dev_attr.attr,
253 	&sensor_dev_attr_in3_input.dev_attr.attr,
254 	&sensor_dev_attr_in4_input.dev_attr.attr,
255 	&sensor_dev_attr_in5_input.dev_attr.attr,
256 	&sensor_dev_attr_in6_input.dev_attr.attr,
257 	&sensor_dev_attr_in7_input.dev_attr.attr,
258 	&sensor_dev_attr_in8_input.dev_attr.attr,
259 	&sensor_dev_attr_in9_input.dev_attr.attr,
260 	&sensor_dev_attr_in10_input.dev_attr.attr,
261 	&sensor_dev_attr_in11_input.dev_attr.attr,
262 	&sensor_dev_attr_in12_input.dev_attr.attr,
263 	&sensor_dev_attr_in13_input.dev_attr.attr,
264 
265 	&sensor_dev_attr_in0_highest.dev_attr.attr,
266 	&sensor_dev_attr_in1_highest.dev_attr.attr,
267 	&sensor_dev_attr_in2_highest.dev_attr.attr,
268 	&sensor_dev_attr_in3_highest.dev_attr.attr,
269 	&sensor_dev_attr_in4_highest.dev_attr.attr,
270 	&sensor_dev_attr_in5_highest.dev_attr.attr,
271 	&sensor_dev_attr_in6_highest.dev_attr.attr,
272 	&sensor_dev_attr_in7_highest.dev_attr.attr,
273 	&sensor_dev_attr_in8_highest.dev_attr.attr,
274 	&sensor_dev_attr_in9_highest.dev_attr.attr,
275 	&sensor_dev_attr_in10_highest.dev_attr.attr,
276 	&sensor_dev_attr_in11_highest.dev_attr.attr,
277 	&sensor_dev_attr_in12_highest.dev_attr.attr,
278 	&sensor_dev_attr_in13_highest.dev_attr.attr,
279 
280 	&sensor_dev_attr_in0_label.dev_attr.attr,
281 	&sensor_dev_attr_in1_label.dev_attr.attr,
282 	&sensor_dev_attr_in2_label.dev_attr.attr,
283 	&sensor_dev_attr_in3_label.dev_attr.attr,
284 	&sensor_dev_attr_in4_label.dev_attr.attr,
285 	&sensor_dev_attr_in5_label.dev_attr.attr,
286 	&sensor_dev_attr_in6_label.dev_attr.attr,
287 	&sensor_dev_attr_in7_label.dev_attr.attr,
288 	&sensor_dev_attr_in8_label.dev_attr.attr,
289 	&sensor_dev_attr_in9_label.dev_attr.attr,
290 	&sensor_dev_attr_in10_label.dev_attr.attr,
291 	&sensor_dev_attr_in11_label.dev_attr.attr,
292 	&sensor_dev_attr_in12_label.dev_attr.attr,
293 	&sensor_dev_attr_in13_label.dev_attr.attr,
294 
295 	NULL
296 };
297 
298 ATTRIBUTE_GROUPS(powr1220);
299 
300 static int powr1220_probe(struct i2c_client *client,
301 		const struct i2c_device_id *id)
302 {
303 	struct powr1220_data *data;
304 	struct device *hwmon_dev;
305 
306 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
307 		return -ENODEV;
308 
309 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
310 	if (!data)
311 		return -ENOMEM;
312 
313 	mutex_init(&data->update_lock);
314 	data->client = client;
315 
316 	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
317 			client->name, data, powr1220_groups);
318 
319 	return PTR_ERR_OR_ZERO(hwmon_dev);
320 }
321 
322 static const struct i2c_device_id powr1220_ids[] = {
323 	{ "powr1220", 0, },
324 	{ }
325 };
326 
327 MODULE_DEVICE_TABLE(i2c, powr1220_ids);
328 
329 static struct i2c_driver powr1220_driver = {
330 	.class		= I2C_CLASS_HWMON,
331 	.driver = {
332 		.name	= "powr1220",
333 	},
334 	.probe		= powr1220_probe,
335 	.id_table	= powr1220_ids,
336 };
337 
338 module_i2c_driver(powr1220_driver);
339 
340 MODULE_AUTHOR("Scott Kanowitz");
341 MODULE_DESCRIPTION("POWR1220 driver");
342 MODULE_LICENSE("GPL");
343