xref: /openbmc/linux/drivers/hwmon/powr1220.c (revision 1975d167)
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 
282 static const struct i2c_device_id powr1220_ids[];
283 
powr1220_probe(struct i2c_client * client)284 static int powr1220_probe(struct i2c_client *client)
285 {
286 	struct powr1220_data *data;
287 	struct device *hwmon_dev;
288 
289 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
290 		return -ENODEV;
291 
292 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
293 	if (!data)
294 		return -ENOMEM;
295 
296 	switch (i2c_match_id(powr1220_ids, client)->driver_data) {
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 	.class		= I2C_CLASS_HWMON,
327 	.driver = {
328 		.name	= "powr1220",
329 	},
330 	.probe		= powr1220_probe,
331 	.id_table	= powr1220_ids,
332 };
333 
334 module_i2c_driver(powr1220_driver);
335 
336 MODULE_AUTHOR("Scott Kanowitz");
337 MODULE_DESCRIPTION("POWR1220 driver");
338 MODULE_LICENSE("GPL");
339