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/dmi.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/device.h>
14 #include <linux/regmap.h>
15 #include <linux/mfd/axp20x.h>
16 #include <linux/platform_device.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/machine.h>
20 #include <linux/iio/driver.h>
23 * This mask enables all ADCs except for the battery temp-sensor (TS), that is
24 * left as-is to avoid breaking charging on devices without a temp-sensor.
26 #define AXP288_ADC_EN_MASK 0xF0
27 #define AXP288_ADC_TS_ENABLE 0x01
29 #define AXP288_ADC_TS_BIAS_MASK GENMASK(5, 4)
30 #define AXP288_ADC_TS_BIAS_20UA (0 << 4)
31 #define AXP288_ADC_TS_BIAS_40UA (1 << 4)
32 #define AXP288_ADC_TS_BIAS_60UA (2 << 4)
33 #define AXP288_ADC_TS_BIAS_80UA (3 << 4)
34 #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
35 #define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
36 #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
37 #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0)
38 #define AXP288_ADC_TS_CURRENT_ON (3 << 0)
44 AXP288_ADC_BATT_CHRG_I,
45 AXP288_ADC_BATT_DISCHRG_I,
50 struct axp288_adc_info {
52 struct regmap *regmap;
56 static const struct iio_chan_spec axp288_adc_channels[] = {
61 .address = AXP288_TS_ADC_H,
62 .datasheet_name = "TS_PIN",
63 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
68 .address = AXP288_PMIC_ADC_H,
69 .datasheet_name = "PMIC_TEMP",
70 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
75 .address = AXP288_GP_ADC_H,
76 .datasheet_name = "GPADC",
77 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
82 .address = AXP20X_BATT_CHRG_I_H,
83 .datasheet_name = "BATT_CHG_I",
84 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
89 .address = AXP20X_BATT_DISCHRG_I_H,
90 .datasheet_name = "BATT_DISCHRG_I",
91 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
96 .address = AXP20X_BATT_V_H,
97 .datasheet_name = "BATT_V",
98 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
102 /* for consumer drivers */
103 static struct iio_map axp288_adc_default_maps[] = {
104 IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
105 IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
106 IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
107 IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
108 IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
109 IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
113 static int axp288_adc_read_channel(int *val, unsigned long address,
114 struct regmap *regmap)
118 if (regmap_bulk_read(regmap, address, buf, 2))
120 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
126 * The current-source used for the battery temp-sensor (TS) is shared
127 * with the GPADC. For proper fuel-gauge and charger operation the TS
128 * current-source needs to be permanently on. But to read the GPADC we
129 * need to temporary switch the TS current-source to ondemand, so that
130 * the GPADC can use it, otherwise we will always read an all 0 value.
132 static int axp288_adc_set_ts(struct axp288_adc_info *info,
133 unsigned int mode, unsigned long address)
137 /* No need to switch the current-source if the TS pin is disabled */
138 if (!info->ts_enabled)
141 /* Channels other than GPADC do not need the current source */
142 if (address != AXP288_GP_ADC_H)
145 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
146 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
150 /* When switching to the GPADC pin give things some time to settle */
151 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
152 usleep_range(6000, 10000);
157 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
158 struct iio_chan_spec const *chan,
159 int *val, int *val2, long mask)
162 struct axp288_adc_info *info = iio_priv(indio_dev);
164 mutex_lock(&indio_dev->mlock);
166 case IIO_CHAN_INFO_RAW:
167 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
169 dev_err(&indio_dev->dev, "GPADC mode\n");
173 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
174 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
176 dev_err(&indio_dev->dev, "TS pin restore\n");
181 mutex_unlock(&indio_dev->mlock);
187 * We rely on the machine's firmware to correctly setup the TS pin bias current
188 * at boot. This lists systems with broken fw where we need to set it ourselves.
190 static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
192 /* Lenovo Ideapad 100S (11 inch) */
194 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
195 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
197 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
202 static int axp288_adc_initialize(struct axp288_adc_info *info)
204 const struct dmi_system_id *bias_override;
205 int ret, adc_enable_val;
207 bias_override = dmi_first_match(axp288_adc_ts_bias_override);
209 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
210 AXP288_ADC_TS_BIAS_MASK,
211 (uintptr_t)bias_override->driver_data);
217 * Determine if the TS pin is enabled and set the TS current-source
220 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
224 if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
225 info->ts_enabled = true;
226 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
227 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
228 AXP288_ADC_TS_CURRENT_ON);
230 info->ts_enabled = false;
231 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
232 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
233 AXP288_ADC_TS_CURRENT_OFF);
238 /* Turn on the ADC for all channels except TS, leave TS as is */
239 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
240 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
243 static const struct iio_info axp288_adc_iio_info = {
244 .read_raw = &axp288_adc_read_raw,
247 static int axp288_adc_probe(struct platform_device *pdev)
250 struct axp288_adc_info *info;
251 struct iio_dev *indio_dev;
252 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
254 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
258 info = iio_priv(indio_dev);
259 info->irq = platform_get_irq(pdev, 0);
262 platform_set_drvdata(pdev, indio_dev);
263 info->regmap = axp20x->regmap;
265 * Set ADC to enabled state at all time, including system suspend.
266 * otherwise internal fuel gauge functionality may be affected.
268 ret = axp288_adc_initialize(info);
270 dev_err(&pdev->dev, "unable to enable ADC device\n");
274 indio_dev->dev.parent = &pdev->dev;
275 indio_dev->name = pdev->name;
276 indio_dev->channels = axp288_adc_channels;
277 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
278 indio_dev->info = &axp288_adc_iio_info;
279 indio_dev->modes = INDIO_DIRECT_MODE;
280 ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
284 ret = iio_device_register(indio_dev);
286 dev_err(&pdev->dev, "unable to register iio device\n");
287 goto err_array_unregister;
291 err_array_unregister:
292 iio_map_array_unregister(indio_dev);
297 static int axp288_adc_remove(struct platform_device *pdev)
299 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
301 iio_device_unregister(indio_dev);
302 iio_map_array_unregister(indio_dev);
307 static const struct platform_device_id axp288_adc_id_table[] = {
308 { .name = "axp288_adc" },
312 static struct platform_driver axp288_adc_driver = {
313 .probe = axp288_adc_probe,
314 .remove = axp288_adc_remove,
315 .id_table = axp288_adc_id_table,
317 .name = "axp288_adc",
321 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
323 module_platform_driver(axp288_adc_driver);
325 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
326 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
327 MODULE_LICENSE("GPL");