xref: /openbmc/linux/drivers/iio/adc/axp288_adc.c (revision d7a3d85e)
1 /*
2  * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
3  *
4  * Copyright (C) 2014 Intel Corporation
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the GNU
15  * General Public License for more details.
16  *
17  */
18 
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/device.h>
22 #include <linux/regmap.h>
23 #include <linux/mfd/axp20x.h>
24 #include <linux/platform_device.h>
25 
26 #include <linux/iio/iio.h>
27 #include <linux/iio/machine.h>
28 #include <linux/iio/driver.h>
29 
30 #define AXP288_ADC_EN_MASK		0xF1
31 #define AXP288_ADC_TS_PIN_GPADC		0xF2
32 #define AXP288_ADC_TS_PIN_ON		0xF3
33 
34 enum axp288_adc_id {
35 	AXP288_ADC_TS,
36 	AXP288_ADC_PMIC,
37 	AXP288_ADC_GP,
38 	AXP288_ADC_BATT_CHRG_I,
39 	AXP288_ADC_BATT_DISCHRG_I,
40 	AXP288_ADC_BATT_V,
41 	AXP288_ADC_NR_CHAN,
42 };
43 
44 struct axp288_adc_info {
45 	int irq;
46 	struct regmap *regmap;
47 };
48 
49 static const struct iio_chan_spec const axp288_adc_channels[] = {
50 	{
51 		.indexed = 1,
52 		.type = IIO_TEMP,
53 		.channel = 0,
54 		.address = AXP288_TS_ADC_H,
55 		.datasheet_name = "TS_PIN",
56 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
57 	}, {
58 		.indexed = 1,
59 		.type = IIO_TEMP,
60 		.channel = 1,
61 		.address = AXP288_PMIC_ADC_H,
62 		.datasheet_name = "PMIC_TEMP",
63 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
64 	}, {
65 		.indexed = 1,
66 		.type = IIO_TEMP,
67 		.channel = 2,
68 		.address = AXP288_GP_ADC_H,
69 		.datasheet_name = "GPADC",
70 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
71 	}, {
72 		.indexed = 1,
73 		.type = IIO_CURRENT,
74 		.channel = 3,
75 		.address = AXP20X_BATT_CHRG_I_H,
76 		.datasheet_name = "BATT_CHG_I",
77 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
78 	}, {
79 		.indexed = 1,
80 		.type = IIO_CURRENT,
81 		.channel = 4,
82 		.address = AXP20X_BATT_DISCHRG_I_H,
83 		.datasheet_name = "BATT_DISCHRG_I",
84 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
85 	}, {
86 		.indexed = 1,
87 		.type = IIO_VOLTAGE,
88 		.channel = 5,
89 		.address = AXP20X_BATT_V_H,
90 		.datasheet_name = "BATT_V",
91 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
92 	},
93 };
94 
95 #define AXP288_ADC_MAP(_adc_channel_label, _consumer_dev_name,	\
96 		_consumer_channel)				\
97 	{							\
98 		.adc_channel_label = _adc_channel_label,	\
99 		.consumer_dev_name = _consumer_dev_name,	\
100 		.consumer_channel = _consumer_channel,		\
101 	}
102 
103 /* for consumer drivers */
104 static struct iio_map axp288_adc_default_maps[] = {
105 	AXP288_ADC_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
106 	AXP288_ADC_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
107 	AXP288_ADC_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
108 	AXP288_ADC_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
109 	AXP288_ADC_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
110 	AXP288_ADC_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
111 	{},
112 };
113 
114 static int axp288_adc_read_channel(int *val, unsigned long address,
115 				struct regmap *regmap)
116 {
117 	u8 buf[2];
118 
119 	if (regmap_bulk_read(regmap, address, buf, 2))
120 		return -EIO;
121 	*val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
122 
123 	return IIO_VAL_INT;
124 }
125 
126 static int axp288_adc_set_ts(struct regmap *regmap, unsigned int mode,
127 				unsigned long address)
128 {
129 	/* channels other than GPADC do not need to switch TS pin */
130 	if (address != AXP288_GP_ADC_H)
131 		return 0;
132 
133 	return regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, mode);
134 }
135 
136 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
137 			struct iio_chan_spec const *chan,
138 			int *val, int *val2, long mask)
139 {
140 	int ret;
141 	struct axp288_adc_info *info = iio_priv(indio_dev);
142 
143 	mutex_lock(&indio_dev->mlock);
144 	switch (mask) {
145 	case IIO_CHAN_INFO_RAW:
146 		if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_GPADC,
147 					chan->address)) {
148 			dev_err(&indio_dev->dev, "GPADC mode\n");
149 			ret = -EINVAL;
150 			break;
151 		}
152 		ret = axp288_adc_read_channel(val, chan->address, info->regmap);
153 		if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_ON,
154 						chan->address))
155 			dev_err(&indio_dev->dev, "TS pin restore\n");
156 		break;
157 	default:
158 		ret = -EINVAL;
159 	}
160 	mutex_unlock(&indio_dev->mlock);
161 
162 	return ret;
163 }
164 
165 static int axp288_adc_set_state(struct regmap *regmap)
166 {
167 	/* ADC should be always enabled for internal FG to function */
168 	if (regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, AXP288_ADC_TS_PIN_ON))
169 		return -EIO;
170 
171 	return regmap_write(regmap, AXP20X_ADC_EN1, AXP288_ADC_EN_MASK);
172 }
173 
174 static const struct iio_info axp288_adc_iio_info = {
175 	.read_raw = &axp288_adc_read_raw,
176 	.driver_module = THIS_MODULE,
177 };
178 
179 static int axp288_adc_probe(struct platform_device *pdev)
180 {
181 	int ret;
182 	struct axp288_adc_info *info;
183 	struct iio_dev *indio_dev;
184 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
185 
186 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
187 	if (!indio_dev)
188 		return -ENOMEM;
189 
190 	info = iio_priv(indio_dev);
191 	info->irq = platform_get_irq(pdev, 0);
192 	if (info->irq < 0) {
193 		dev_err(&pdev->dev, "no irq resource?\n");
194 		return info->irq;
195 	}
196 	platform_set_drvdata(pdev, indio_dev);
197 	info->regmap = axp20x->regmap;
198 	/*
199 	 * Set ADC to enabled state at all time, including system suspend.
200 	 * otherwise internal fuel gauge functionality may be affected.
201 	 */
202 	ret = axp288_adc_set_state(axp20x->regmap);
203 	if (ret) {
204 		dev_err(&pdev->dev, "unable to enable ADC device\n");
205 		return ret;
206 	}
207 
208 	indio_dev->dev.parent = &pdev->dev;
209 	indio_dev->name = pdev->name;
210 	indio_dev->channels = axp288_adc_channels;
211 	indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
212 	indio_dev->info = &axp288_adc_iio_info;
213 	indio_dev->modes = INDIO_DIRECT_MODE;
214 	ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
215 	if (ret < 0)
216 		return ret;
217 
218 	ret = iio_device_register(indio_dev);
219 	if (ret < 0) {
220 		dev_err(&pdev->dev, "unable to register iio device\n");
221 		goto err_array_unregister;
222 	}
223 	return 0;
224 
225 err_array_unregister:
226 	iio_map_array_unregister(indio_dev);
227 
228 	return ret;
229 }
230 
231 static int axp288_adc_remove(struct platform_device *pdev)
232 {
233 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
234 
235 	iio_device_unregister(indio_dev);
236 	iio_map_array_unregister(indio_dev);
237 
238 	return 0;
239 }
240 
241 static struct platform_device_id axp288_adc_id_table[] = {
242 	{ .name = "axp288_adc" },
243 	{},
244 };
245 
246 static struct platform_driver axp288_adc_driver = {
247 	.probe = axp288_adc_probe,
248 	.remove = axp288_adc_remove,
249 	.id_table = axp288_adc_id_table,
250 	.driver = {
251 		.name = "axp288_adc",
252 	},
253 };
254 
255 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
256 
257 module_platform_driver(axp288_adc_driver);
258 
259 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
260 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
261 MODULE_LICENSE("GPL");
262