xref: /openbmc/linux/drivers/hwmon/da9055-hwmon.c (revision d2574c33)
1 /*
2  * HWMON Driver for Dialog DA9055
3  *
4  * Copyright(c) 2012 Dialog Semiconductor Ltd.
5  *
6  * Author: David Dajun Chen <dchen@diasemi.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  *
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/hwmon.h>
18 #include <linux/hwmon-sysfs.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/completion.h>
24 
25 #include <linux/mfd/da9055/core.h>
26 #include <linux/mfd/da9055/reg.h>
27 
28 #define DA9055_ADCIN_DIV	102
29 #define DA9055_VSYS_DIV	85
30 
31 #define DA9055_ADC_VSYS	0
32 #define DA9055_ADC_ADCIN1	1
33 #define DA9055_ADC_ADCIN2	2
34 #define DA9055_ADC_ADCIN3	3
35 #define DA9055_ADC_TJUNC	4
36 
37 struct da9055_hwmon {
38 	struct da9055	*da9055;
39 	struct mutex	hwmon_lock;
40 	struct mutex	irq_lock;
41 	struct completion done;
42 };
43 
44 static const char * const input_names[] = {
45 	[DA9055_ADC_VSYS]	= "VSYS",
46 	[DA9055_ADC_ADCIN1]	= "ADC IN1",
47 	[DA9055_ADC_ADCIN2]	= "ADC IN2",
48 	[DA9055_ADC_ADCIN3]	= "ADC IN3",
49 	[DA9055_ADC_TJUNC]	= "CHIP TEMP",
50 };
51 
52 static const u8 chan_mux[DA9055_ADC_TJUNC + 1] = {
53 	[DA9055_ADC_VSYS]	= DA9055_ADC_MUX_VSYS,
54 	[DA9055_ADC_ADCIN1]	= DA9055_ADC_MUX_ADCIN1,
55 	[DA9055_ADC_ADCIN2]	= DA9055_ADC_MUX_ADCIN2,
56 	[DA9055_ADC_ADCIN3]	= DA9055_ADC_MUX_ADCIN3,
57 	[DA9055_ADC_TJUNC]	= DA9055_ADC_MUX_T_SENSE,
58 };
59 
60 static int da9055_adc_manual_read(struct da9055_hwmon *hwmon,
61 					unsigned char channel)
62 {
63 	int ret;
64 	unsigned short calc_data;
65 	unsigned short data;
66 	unsigned char mux_sel;
67 	struct da9055 *da9055 = hwmon->da9055;
68 
69 	if (channel > DA9055_ADC_TJUNC)
70 		return -EINVAL;
71 
72 	mutex_lock(&hwmon->irq_lock);
73 
74 	/* Selects desired MUX for manual conversion */
75 	mux_sel = chan_mux[channel] | DA9055_ADC_MAN_CONV;
76 
77 	ret = da9055_reg_write(da9055, DA9055_REG_ADC_MAN, mux_sel);
78 	if (ret < 0)
79 		goto err;
80 
81 	/* Wait for an interrupt */
82 	if (!wait_for_completion_timeout(&hwmon->done,
83 					msecs_to_jiffies(500))) {
84 		dev_err(da9055->dev,
85 			"timeout waiting for ADC conversion interrupt\n");
86 		ret = -ETIMEDOUT;
87 		goto err;
88 	}
89 
90 	ret = da9055_reg_read(da9055, DA9055_REG_ADC_RES_H);
91 	if (ret < 0)
92 		goto err;
93 
94 	calc_data = (unsigned short)ret;
95 	data = calc_data << 2;
96 
97 	ret = da9055_reg_read(da9055, DA9055_REG_ADC_RES_L);
98 	if (ret < 0)
99 		goto err;
100 
101 	calc_data = (unsigned short)(ret & DA9055_ADC_LSB_MASK);
102 	data |= calc_data;
103 
104 	ret = data;
105 
106 err:
107 	mutex_unlock(&hwmon->irq_lock);
108 	return ret;
109 }
110 
111 static irqreturn_t da9055_auxadc_irq(int irq, void *irq_data)
112 {
113 	struct da9055_hwmon *hwmon = irq_data;
114 
115 	complete(&hwmon->done);
116 
117 	return IRQ_HANDLED;
118 }
119 
120 /* Conversion function for VSYS and ADCINx */
121 static inline int volt_reg_to_mv(int value, int channel)
122 {
123 	if (channel == DA9055_ADC_VSYS)
124 		return DIV_ROUND_CLOSEST(value * 1000, DA9055_VSYS_DIV) + 2500;
125 	else
126 		return DIV_ROUND_CLOSEST(value * 1000, DA9055_ADCIN_DIV);
127 }
128 
129 static int da9055_enable_auto_mode(struct da9055 *da9055, int channel)
130 {
131 
132 	return da9055_reg_update(da9055, DA9055_REG_ADC_CONT, 1 << channel,
133 				1 << channel);
134 
135 }
136 
137 static int da9055_disable_auto_mode(struct da9055 *da9055, int channel)
138 {
139 
140 	return da9055_reg_update(da9055, DA9055_REG_ADC_CONT, 1 << channel, 0);
141 }
142 
143 static ssize_t da9055_auto_ch_show(struct device *dev,
144 				   struct device_attribute *devattr,
145 				   char *buf)
146 {
147 	struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
148 	int ret, adc;
149 	int channel = to_sensor_dev_attr(devattr)->index;
150 
151 	mutex_lock(&hwmon->hwmon_lock);
152 
153 	ret = da9055_enable_auto_mode(hwmon->da9055, channel);
154 	if (ret < 0)
155 		goto hwmon_err;
156 
157 	usleep_range(10000, 10500);
158 
159 	adc = da9055_reg_read(hwmon->da9055, DA9055_REG_VSYS_RES + channel);
160 	if (adc < 0) {
161 		ret = adc;
162 		goto hwmon_err_release;
163 	}
164 
165 	ret = da9055_disable_auto_mode(hwmon->da9055, channel);
166 	if (ret < 0)
167 		goto hwmon_err;
168 
169 	mutex_unlock(&hwmon->hwmon_lock);
170 
171 	return sprintf(buf, "%d\n", volt_reg_to_mv(adc, channel));
172 
173 hwmon_err_release:
174 	da9055_disable_auto_mode(hwmon->da9055, channel);
175 hwmon_err:
176 	mutex_unlock(&hwmon->hwmon_lock);
177 	return ret;
178 }
179 
180 static ssize_t da9055_tjunc_show(struct device *dev,
181 				 struct device_attribute *devattr, char *buf)
182 {
183 	struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
184 	int tjunc;
185 	int toffset;
186 
187 	tjunc = da9055_adc_manual_read(hwmon, DA9055_ADC_TJUNC);
188 	if (tjunc < 0)
189 		return tjunc;
190 
191 	toffset = da9055_reg_read(hwmon->da9055, DA9055_REG_T_OFFSET);
192 	if (toffset < 0)
193 		return toffset;
194 
195 	/*
196 	 * Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332
197 	 * T_OFFSET is a trim value used to improve accuracy of the result
198 	 */
199 	return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(-4084 * (tjunc - toffset)
200 							+ 3076332, 10000));
201 }
202 
203 static ssize_t label_show(struct device *dev,
204 			  struct device_attribute *devattr, char *buf)
205 {
206 	return sprintf(buf, "%s\n",
207 		       input_names[to_sensor_dev_attr(devattr)->index]);
208 }
209 
210 static SENSOR_DEVICE_ATTR_RO(in0_input, da9055_auto_ch, DA9055_ADC_VSYS);
211 static SENSOR_DEVICE_ATTR_RO(in0_label, label, DA9055_ADC_VSYS);
212 static SENSOR_DEVICE_ATTR_RO(in1_input, da9055_auto_ch, DA9055_ADC_ADCIN1);
213 static SENSOR_DEVICE_ATTR_RO(in1_label, label, DA9055_ADC_ADCIN1);
214 static SENSOR_DEVICE_ATTR_RO(in2_input, da9055_auto_ch, DA9055_ADC_ADCIN2);
215 static SENSOR_DEVICE_ATTR_RO(in2_label, label, DA9055_ADC_ADCIN2);
216 static SENSOR_DEVICE_ATTR_RO(in3_input, da9055_auto_ch, DA9055_ADC_ADCIN3);
217 static SENSOR_DEVICE_ATTR_RO(in3_label, label, DA9055_ADC_ADCIN3);
218 
219 static SENSOR_DEVICE_ATTR_RO(temp1_input, da9055_tjunc, DA9055_ADC_TJUNC);
220 static SENSOR_DEVICE_ATTR_RO(temp1_label, label, DA9055_ADC_TJUNC);
221 
222 static struct attribute *da9055_attrs[] = {
223 	&sensor_dev_attr_in0_input.dev_attr.attr,
224 	&sensor_dev_attr_in0_label.dev_attr.attr,
225 	&sensor_dev_attr_in1_input.dev_attr.attr,
226 	&sensor_dev_attr_in1_label.dev_attr.attr,
227 	&sensor_dev_attr_in2_input.dev_attr.attr,
228 	&sensor_dev_attr_in2_label.dev_attr.attr,
229 	&sensor_dev_attr_in3_input.dev_attr.attr,
230 	&sensor_dev_attr_in3_label.dev_attr.attr,
231 
232 	&sensor_dev_attr_temp1_input.dev_attr.attr,
233 	&sensor_dev_attr_temp1_label.dev_attr.attr,
234 	NULL
235 };
236 
237 ATTRIBUTE_GROUPS(da9055);
238 
239 static int da9055_hwmon_probe(struct platform_device *pdev)
240 {
241 	struct device *dev = &pdev->dev;
242 	struct da9055_hwmon *hwmon;
243 	struct device *hwmon_dev;
244 	int hwmon_irq, ret;
245 
246 	hwmon = devm_kzalloc(dev, sizeof(struct da9055_hwmon), GFP_KERNEL);
247 	if (!hwmon)
248 		return -ENOMEM;
249 
250 	mutex_init(&hwmon->hwmon_lock);
251 	mutex_init(&hwmon->irq_lock);
252 
253 	init_completion(&hwmon->done);
254 	hwmon->da9055 = dev_get_drvdata(pdev->dev.parent);
255 
256 	hwmon_irq = platform_get_irq_byname(pdev, "HWMON");
257 	if (hwmon_irq < 0)
258 		return hwmon_irq;
259 
260 	ret = devm_request_threaded_irq(&pdev->dev, hwmon_irq,
261 					NULL, da9055_auxadc_irq,
262 					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
263 					"adc-irq", hwmon);
264 	if (ret != 0) {
265 		dev_err(hwmon->da9055->dev, "DA9055 ADC IRQ failed ret=%d\n",
266 			ret);
267 		return ret;
268 	}
269 
270 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, "da9055",
271 							   hwmon,
272 							   da9055_groups);
273 	return PTR_ERR_OR_ZERO(hwmon_dev);
274 }
275 
276 static struct platform_driver da9055_hwmon_driver = {
277 	.probe = da9055_hwmon_probe,
278 	.driver = {
279 		.name = "da9055-hwmon",
280 	},
281 };
282 
283 module_platform_driver(da9055_hwmon_driver);
284 
285 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
286 MODULE_DESCRIPTION("DA9055 HWMON driver");
287 MODULE_LICENSE("GPL");
288 MODULE_ALIAS("platform:da9055-hwmon");
289