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 powr1xxx_chips { powr1014, powr1220 };
26
27 enum powr1220_regs {
28 VMON_STATUS0,
29 VMON_STATUS1,
30 VMON_STATUS2,
31 OUTPUT_STATUS0,
32 OUTPUT_STATUS1,
33 OUTPUT_STATUS2,
34 INPUT_STATUS,
35 ADC_VALUE_LOW,
36 ADC_VALUE_HIGH,
37 ADC_MUX,
38 UES_BYTE0,
39 UES_BYTE1,
40 UES_BYTE2,
41 UES_BYTE3,
42 GP_OUTPUT1,
43 GP_OUTPUT2,
44 GP_OUTPUT3,
45 INPUT_VALUE,
46 RESET,
47 TRIM1_TRIM,
48 TRIM2_TRIM,
49 TRIM3_TRIM,
50 TRIM4_TRIM,
51 TRIM5_TRIM,
52 TRIM6_TRIM,
53 TRIM7_TRIM,
54 TRIM8_TRIM,
55 MAX_POWR1220_REGS
56 };
57
58 enum powr1220_adc_values {
59 VMON1,
60 VMON2,
61 VMON3,
62 VMON4,
63 VMON5,
64 VMON6,
65 VMON7,
66 VMON8,
67 VMON9,
68 VMON10,
69 VMON11,
70 VMON12,
71 VCCA,
72 VCCINP,
73 MAX_POWR1220_ADC_VALUES
74 };
75
76 struct powr1220_data {
77 struct i2c_client *client;
78 struct mutex update_lock;
79 u8 max_channels;
80 bool adc_valid[MAX_POWR1220_ADC_VALUES];
81 /* the next value is in jiffies */
82 unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
83
84 /* values */
85 int adc_maxes[MAX_POWR1220_ADC_VALUES];
86 int adc_values[MAX_POWR1220_ADC_VALUES];
87 };
88
89 static const char * const input_names[] = {
90 [VMON1] = "vmon1",
91 [VMON2] = "vmon2",
92 [VMON3] = "vmon3",
93 [VMON4] = "vmon4",
94 [VMON5] = "vmon5",
95 [VMON6] = "vmon6",
96 [VMON7] = "vmon7",
97 [VMON8] = "vmon8",
98 [VMON9] = "vmon9",
99 [VMON10] = "vmon10",
100 [VMON11] = "vmon11",
101 [VMON12] = "vmon12",
102 [VCCA] = "vcca",
103 [VCCINP] = "vccinp",
104 };
105
106 /* Reads the specified ADC channel */
powr1220_read_adc(struct device * dev,int ch_num)107 static int powr1220_read_adc(struct device *dev, int ch_num)
108 {
109 struct powr1220_data *data = dev_get_drvdata(dev);
110 int reading;
111 int result;
112 int adc_range = 0;
113
114 mutex_lock(&data->update_lock);
115
116 if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
117 !data->adc_valid[ch_num]) {
118 /*
119 * figure out if we need to use the attenuator for
120 * high inputs or inputs that we don't yet have a measurement
121 * for. We dynamically set the attenuator depending on the
122 * max reading.
123 */
124 if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
125 data->adc_maxes[ch_num] == 0)
126 adc_range = 1 << 4;
127
128 /* set the attenuator and mux */
129 result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
130 adc_range | ch_num);
131 if (result)
132 goto exit;
133
134 /*
135 * wait at least Tconvert time (200 us) for the
136 * conversion to complete
137 */
138 udelay(200);
139
140 /* get the ADC reading */
141 result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
142 if (result < 0)
143 goto exit;
144
145 reading = result >> 4;
146
147 /* get the upper half of the reading */
148 result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
149 if (result < 0)
150 goto exit;
151
152 reading |= result << 4;
153
154 /* now convert the reading to a voltage */
155 reading *= ADC_STEP_MV;
156 data->adc_values[ch_num] = reading;
157 data->adc_valid[ch_num] = true;
158 data->adc_last_updated[ch_num] = jiffies;
159 result = reading;
160
161 if (reading > data->adc_maxes[ch_num])
162 data->adc_maxes[ch_num] = reading;
163 } else {
164 result = data->adc_values[ch_num];
165 }
166
167 exit:
168 mutex_unlock(&data->update_lock);
169
170 return result;
171 }
172
173 static umode_t
powr1220_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)174 powr1220_is_visible(const void *data, enum hwmon_sensor_types type, u32
175 attr, int channel)
176 {
177 struct powr1220_data *chip_data = (struct powr1220_data *)data;
178
179 if (channel >= chip_data->max_channels)
180 return 0;
181
182 switch (type) {
183 case hwmon_in:
184 switch (attr) {
185 case hwmon_in_input:
186 case hwmon_in_highest:
187 case hwmon_in_label:
188 return 0444;
189 default:
190 break;
191 }
192 break;
193 default:
194 break;
195 }
196
197 return 0;
198 }
199
200 static int
powr1220_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)201 powr1220_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
202 int channel, const char **str)
203 {
204 switch (type) {
205 case hwmon_in:
206 switch (attr) {
207 case hwmon_in_label:
208 *str = input_names[channel];
209 return 0;
210 default:
211 return -EOPNOTSUPP;
212 }
213 break;
214 default:
215 return -EOPNOTSUPP;
216 }
217
218 return -EOPNOTSUPP;
219 }
220
221 static int
powr1220_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)222 powr1220_read(struct device *dev, enum hwmon_sensor_types type, u32
223 attr, int channel, long *val)
224 {
225 struct powr1220_data *data = dev_get_drvdata(dev);
226 int ret;
227
228 switch (type) {
229 case hwmon_in:
230 switch (attr) {
231 case hwmon_in_input:
232 ret = powr1220_read_adc(dev, channel);
233 if (ret < 0)
234 return ret;
235 *val = ret;
236 break;
237 case hwmon_in_highest:
238 *val = data->adc_maxes[channel];
239 break;
240 default:
241 return -EOPNOTSUPP;
242 }
243 break;
244 default:
245 return -EOPNOTSUPP;
246 }
247
248 return 0;
249 }
250
251 static const struct hwmon_channel_info * const powr1220_info[] = {
252 HWMON_CHANNEL_INFO(in,
253 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
254 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
255 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
256 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
257 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
258 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
259 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
260 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
261 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
262 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
263 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
264 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
265 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
266 HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL),
267
268 NULL
269 };
270
271 static const struct hwmon_ops powr1220_hwmon_ops = {
272 .read = powr1220_read,
273 .read_string = powr1220_read_string,
274 .is_visible = powr1220_is_visible,
275 };
276
277 static const struct hwmon_chip_info powr1220_chip_info = {
278 .ops = &powr1220_hwmon_ops,
279 .info = powr1220_info,
280 };
281
powr1220_probe(struct i2c_client * client)282 static int powr1220_probe(struct i2c_client *client)
283 {
284 struct powr1220_data *data;
285 struct device *hwmon_dev;
286 enum powr1xxx_chips chip;
287
288 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
289 return -ENODEV;
290
291 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
292 if (!data)
293 return -ENOMEM;
294
295 chip = (uintptr_t)i2c_get_match_data(client);
296 switch (chip) {
297 case powr1014:
298 data->max_channels = 10;
299 break;
300 default:
301 data->max_channels = 12;
302 break;
303 }
304
305 mutex_init(&data->update_lock);
306 data->client = client;
307
308 hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
309 client->name,
310 data,
311 &powr1220_chip_info,
312 NULL);
313
314 return PTR_ERR_OR_ZERO(hwmon_dev);
315 }
316
317 static const struct i2c_device_id powr1220_ids[] = {
318 { "powr1014", powr1014, },
319 { "powr1220", powr1220, },
320 { }
321 };
322
323 MODULE_DEVICE_TABLE(i2c, powr1220_ids);
324
325 static struct i2c_driver powr1220_driver = {
326 .driver = {
327 .name = "powr1220",
328 },
329 .probe = powr1220_probe,
330 .id_table = powr1220_ids,
331 };
332
333 module_i2c_driver(powr1220_driver);
334
335 MODULE_AUTHOR("Scott Kanowitz");
336 MODULE_DESCRIPTION("POWR1220 driver");
337 MODULE_LICENSE("GPL");
338