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
37struct da9055_hwmon {
38	struct da9055	*da9055;
39	struct mutex	hwmon_lock;
40	struct mutex	irq_lock;
41	struct completion done;
42};
43
44static 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
52static 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
60static 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
106err:
107	mutex_unlock(&hwmon->irq_lock);
108	return ret;
109}
110
111static 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 */
121static 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
129static 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
137static 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
143static ssize_t da9055_read_auto_ch(struct device *dev,
144				struct device_attribute *devattr, char *buf)
145{
146	struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
147	int ret, adc;
148	int channel = to_sensor_dev_attr(devattr)->index;
149
150	mutex_lock(&hwmon->hwmon_lock);
151
152	ret = da9055_enable_auto_mode(hwmon->da9055, channel);
153	if (ret < 0)
154		goto hwmon_err;
155
156	usleep_range(10000, 10500);
157
158	adc = da9055_reg_read(hwmon->da9055, DA9055_REG_VSYS_RES + channel);
159	if (adc < 0) {
160		ret = adc;
161		goto hwmon_err_release;
162	}
163
164	ret = da9055_disable_auto_mode(hwmon->da9055, channel);
165	if (ret < 0)
166		goto hwmon_err;
167
168	mutex_unlock(&hwmon->hwmon_lock);
169
170	return sprintf(buf, "%d\n", volt_reg_to_mv(adc, channel));
171
172hwmon_err_release:
173	da9055_disable_auto_mode(hwmon->da9055, channel);
174hwmon_err:
175	mutex_unlock(&hwmon->hwmon_lock);
176	return ret;
177}
178
179static ssize_t da9055_read_tjunc(struct device *dev,
180				 struct device_attribute *devattr, char *buf)
181{
182	struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
183	int tjunc;
184	int toffset;
185
186	tjunc = da9055_adc_manual_read(hwmon, DA9055_ADC_TJUNC);
187	if (tjunc < 0)
188		return tjunc;
189
190	toffset = da9055_reg_read(hwmon->da9055, DA9055_REG_T_OFFSET);
191	if (toffset < 0)
192		return toffset;
193
194	/*
195	 * Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332
196	 * T_OFFSET is a trim value used to improve accuracy of the result
197	 */
198	return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(-4084 * (tjunc - toffset)
199							+ 3076332, 10000));
200}
201
202static ssize_t show_label(struct device *dev,
203			  struct device_attribute *devattr, char *buf)
204{
205	return sprintf(buf, "%s\n",
206		       input_names[to_sensor_dev_attr(devattr)->index]);
207}
208
209static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, da9055_read_auto_ch, NULL,
210			  DA9055_ADC_VSYS);
211static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO, show_label, NULL,
212			  DA9055_ADC_VSYS);
213static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, da9055_read_auto_ch, NULL,
214			  DA9055_ADC_ADCIN1);
215static SENSOR_DEVICE_ATTR(in1_label, S_IRUGO, show_label, NULL,
216			  DA9055_ADC_ADCIN1);
217static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, da9055_read_auto_ch, NULL,
218			  DA9055_ADC_ADCIN2);
219static SENSOR_DEVICE_ATTR(in2_label, S_IRUGO, show_label, NULL,
220			  DA9055_ADC_ADCIN2);
221static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, da9055_read_auto_ch, NULL,
222			  DA9055_ADC_ADCIN3);
223static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, show_label, NULL,
224			  DA9055_ADC_ADCIN3);
225
226static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, da9055_read_tjunc, NULL,
227			  DA9055_ADC_TJUNC);
228static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
229			  DA9055_ADC_TJUNC);
230
231static struct attribute *da9055_attrs[] = {
232	&sensor_dev_attr_in0_input.dev_attr.attr,
233	&sensor_dev_attr_in0_label.dev_attr.attr,
234	&sensor_dev_attr_in1_input.dev_attr.attr,
235	&sensor_dev_attr_in1_label.dev_attr.attr,
236	&sensor_dev_attr_in2_input.dev_attr.attr,
237	&sensor_dev_attr_in2_label.dev_attr.attr,
238	&sensor_dev_attr_in3_input.dev_attr.attr,
239	&sensor_dev_attr_in3_label.dev_attr.attr,
240
241	&sensor_dev_attr_temp1_input.dev_attr.attr,
242	&sensor_dev_attr_temp1_label.dev_attr.attr,
243	NULL
244};
245
246ATTRIBUTE_GROUPS(da9055);
247
248static int da9055_hwmon_probe(struct platform_device *pdev)
249{
250	struct device *dev = &pdev->dev;
251	struct da9055_hwmon *hwmon;
252	struct device *hwmon_dev;
253	int hwmon_irq, ret;
254
255	hwmon = devm_kzalloc(dev, sizeof(struct da9055_hwmon), GFP_KERNEL);
256	if (!hwmon)
257		return -ENOMEM;
258
259	mutex_init(&hwmon->hwmon_lock);
260	mutex_init(&hwmon->irq_lock);
261
262	init_completion(&hwmon->done);
263	hwmon->da9055 = dev_get_drvdata(pdev->dev.parent);
264
265	hwmon_irq = platform_get_irq_byname(pdev, "HWMON");
266	if (hwmon_irq < 0)
267		return hwmon_irq;
268
269	ret = devm_request_threaded_irq(&pdev->dev, hwmon_irq,
270					NULL, da9055_auxadc_irq,
271					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
272					"adc-irq", hwmon);
273	if (ret != 0) {
274		dev_err(hwmon->da9055->dev, "DA9055 ADC IRQ failed ret=%d\n",
275			ret);
276		return ret;
277	}
278
279	hwmon_dev = devm_hwmon_device_register_with_groups(dev, "da9055",
280							   hwmon,
281							   da9055_groups);
282	return PTR_ERR_OR_ZERO(hwmon_dev);
283}
284
285static struct platform_driver da9055_hwmon_driver = {
286	.probe = da9055_hwmon_probe,
287	.driver = {
288		.name = "da9055-hwmon",
289	},
290};
291
292module_platform_driver(da9055_hwmon_driver);
293
294MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
295MODULE_DESCRIPTION("DA9055 HWMON driver");
296MODULE_LICENSE("GPL");
297MODULE_ALIAS("platform:da9055-hwmon");
298