1 // SPDX-License-Identifier: GPL-2.0-only
3 * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
5 * Copyright (C) 2014 Intel Corporation
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/device.h>
13 #include <linux/regmap.h>
14 #include <linux/mfd/axp20x.h>
15 #include <linux/platform_device.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/machine.h>
19 #include <linux/iio/driver.h>
22 * This mask enables all ADCs except for the battery temp-sensor (TS), that is
23 * left as-is to avoid breaking charging on devices without a temp-sensor.
25 #define AXP288_ADC_EN_MASK 0xF0
26 #define AXP288_ADC_TS_ENABLE 0x01
28 #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
29 #define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
30 #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
31 #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0)
32 #define AXP288_ADC_TS_CURRENT_ON (3 << 0)
38 AXP288_ADC_BATT_CHRG_I,
39 AXP288_ADC_BATT_DISCHRG_I,
44 struct axp288_adc_info {
46 struct regmap *regmap;
50 static const struct iio_chan_spec axp288_adc_channels[] = {
55 .address = AXP288_TS_ADC_H,
56 .datasheet_name = "TS_PIN",
57 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
62 .address = AXP288_PMIC_ADC_H,
63 .datasheet_name = "PMIC_TEMP",
64 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
69 .address = AXP288_GP_ADC_H,
70 .datasheet_name = "GPADC",
71 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
76 .address = AXP20X_BATT_CHRG_I_H,
77 .datasheet_name = "BATT_CHG_I",
78 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
83 .address = AXP20X_BATT_DISCHRG_I_H,
84 .datasheet_name = "BATT_DISCHRG_I",
85 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
90 .address = AXP20X_BATT_V_H,
91 .datasheet_name = "BATT_V",
92 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
96 /* for consumer drivers */
97 static struct iio_map axp288_adc_default_maps[] = {
98 IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
99 IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
100 IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
101 IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
102 IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
103 IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
107 static int axp288_adc_read_channel(int *val, unsigned long address,
108 struct regmap *regmap)
112 if (regmap_bulk_read(regmap, address, buf, 2))
114 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
120 * The current-source used for the battery temp-sensor (TS) is shared
121 * with the GPADC. For proper fuel-gauge and charger operation the TS
122 * current-source needs to be permanently on. But to read the GPADC we
123 * need to temporary switch the TS current-source to ondemand, so that
124 * the GPADC can use it, otherwise we will always read an all 0 value.
126 static int axp288_adc_set_ts(struct axp288_adc_info *info,
127 unsigned int mode, unsigned long address)
131 /* No need to switch the current-source if the TS pin is disabled */
132 if (!info->ts_enabled)
135 /* Channels other than GPADC do not need the current source */
136 if (address != AXP288_GP_ADC_H)
139 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
140 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
144 /* When switching to the GPADC pin give things some time to settle */
145 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
146 usleep_range(6000, 10000);
151 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
152 struct iio_chan_spec const *chan,
153 int *val, int *val2, long mask)
156 struct axp288_adc_info *info = iio_priv(indio_dev);
158 mutex_lock(&indio_dev->mlock);
160 case IIO_CHAN_INFO_RAW:
161 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
163 dev_err(&indio_dev->dev, "GPADC mode\n");
167 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
168 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
170 dev_err(&indio_dev->dev, "TS pin restore\n");
175 mutex_unlock(&indio_dev->mlock);
180 static int axp288_adc_initialize(struct axp288_adc_info *info)
182 int ret, adc_enable_val;
185 * Determine if the TS pin is enabled and set the TS current-source
188 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
192 if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
193 info->ts_enabled = true;
194 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
195 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
196 AXP288_ADC_TS_CURRENT_ON);
198 info->ts_enabled = false;
199 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
200 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
201 AXP288_ADC_TS_CURRENT_OFF);
206 /* Turn on the ADC for all channels except TS, leave TS as is */
207 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
208 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
211 static const struct iio_info axp288_adc_iio_info = {
212 .read_raw = &axp288_adc_read_raw,
215 static int axp288_adc_probe(struct platform_device *pdev)
218 struct axp288_adc_info *info;
219 struct iio_dev *indio_dev;
220 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
222 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
226 info = iio_priv(indio_dev);
227 info->irq = platform_get_irq(pdev, 0);
230 platform_set_drvdata(pdev, indio_dev);
231 info->regmap = axp20x->regmap;
233 * Set ADC to enabled state at all time, including system suspend.
234 * otherwise internal fuel gauge functionality may be affected.
236 ret = axp288_adc_initialize(info);
238 dev_err(&pdev->dev, "unable to enable ADC device\n");
242 indio_dev->dev.parent = &pdev->dev;
243 indio_dev->name = pdev->name;
244 indio_dev->channels = axp288_adc_channels;
245 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
246 indio_dev->info = &axp288_adc_iio_info;
247 indio_dev->modes = INDIO_DIRECT_MODE;
248 ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
252 ret = iio_device_register(indio_dev);
254 dev_err(&pdev->dev, "unable to register iio device\n");
255 goto err_array_unregister;
259 err_array_unregister:
260 iio_map_array_unregister(indio_dev);
265 static int axp288_adc_remove(struct platform_device *pdev)
267 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
269 iio_device_unregister(indio_dev);
270 iio_map_array_unregister(indio_dev);
275 static const struct platform_device_id axp288_adc_id_table[] = {
276 { .name = "axp288_adc" },
280 static struct platform_driver axp288_adc_driver = {
281 .probe = axp288_adc_probe,
282 .remove = axp288_adc_remove,
283 .id_table = axp288_adc_id_table,
285 .name = "axp288_adc",
289 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
291 module_platform_driver(axp288_adc_driver);
293 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
294 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
295 MODULE_LICENSE("GPL");