2 * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
4 * Copyright (C) 2014 Intel Corporation
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
19 #include <linux/dmi.h>
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/device.h>
23 #include <linux/regmap.h>
24 #include <linux/mfd/axp20x.h>
25 #include <linux/platform_device.h>
27 #include <linux/iio/iio.h>
28 #include <linux/iio/machine.h>
29 #include <linux/iio/driver.h>
32 * This mask enables all ADCs except for the battery temp-sensor (TS), that is
33 * left as-is to avoid breaking charging on devices without a temp-sensor.
35 #define AXP288_ADC_EN_MASK 0xF0
36 #define AXP288_ADC_TS_ENABLE 0x01
38 #define AXP288_ADC_TS_BIAS_MASK GENMASK(5, 4)
39 #define AXP288_ADC_TS_BIAS_20UA (0 << 4)
40 #define AXP288_ADC_TS_BIAS_40UA (1 << 4)
41 #define AXP288_ADC_TS_BIAS_60UA (2 << 4)
42 #define AXP288_ADC_TS_BIAS_80UA (3 << 4)
43 #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
44 #define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
45 #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
46 #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0)
47 #define AXP288_ADC_TS_CURRENT_ON (3 << 0)
53 AXP288_ADC_BATT_CHRG_I,
54 AXP288_ADC_BATT_DISCHRG_I,
59 struct axp288_adc_info {
61 struct regmap *regmap;
65 static const struct iio_chan_spec axp288_adc_channels[] = {
70 .address = AXP288_TS_ADC_H,
71 .datasheet_name = "TS_PIN",
72 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
77 .address = AXP288_PMIC_ADC_H,
78 .datasheet_name = "PMIC_TEMP",
79 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
84 .address = AXP288_GP_ADC_H,
85 .datasheet_name = "GPADC",
86 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
91 .address = AXP20X_BATT_CHRG_I_H,
92 .datasheet_name = "BATT_CHG_I",
93 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
98 .address = AXP20X_BATT_DISCHRG_I_H,
99 .datasheet_name = "BATT_DISCHRG_I",
100 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
105 .address = AXP20X_BATT_V_H,
106 .datasheet_name = "BATT_V",
107 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
111 #define AXP288_ADC_MAP(_adc_channel_label, _consumer_dev_name, \
114 .adc_channel_label = _adc_channel_label, \
115 .consumer_dev_name = _consumer_dev_name, \
116 .consumer_channel = _consumer_channel, \
119 /* for consumer drivers */
120 static struct iio_map axp288_adc_default_maps[] = {
121 AXP288_ADC_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
122 AXP288_ADC_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
123 AXP288_ADC_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
124 AXP288_ADC_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
125 AXP288_ADC_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
126 AXP288_ADC_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
130 static int axp288_adc_read_channel(int *val, unsigned long address,
131 struct regmap *regmap)
135 if (regmap_bulk_read(regmap, address, buf, 2))
137 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
143 * The current-source used for the battery temp-sensor (TS) is shared
144 * with the GPADC. For proper fuel-gauge and charger operation the TS
145 * current-source needs to be permanently on. But to read the GPADC we
146 * need to temporary switch the TS current-source to ondemand, so that
147 * the GPADC can use it, otherwise we will always read an all 0 value.
149 static int axp288_adc_set_ts(struct axp288_adc_info *info,
150 unsigned int mode, unsigned long address)
154 /* No need to switch the current-source if the TS pin is disabled */
155 if (!info->ts_enabled)
158 /* Channels other than GPADC do not need the current source */
159 if (address != AXP288_GP_ADC_H)
162 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
163 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
167 /* When switching to the GPADC pin give things some time to settle */
168 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
169 usleep_range(6000, 10000);
174 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
175 struct iio_chan_spec const *chan,
176 int *val, int *val2, long mask)
179 struct axp288_adc_info *info = iio_priv(indio_dev);
181 mutex_lock(&indio_dev->mlock);
183 case IIO_CHAN_INFO_RAW:
184 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
186 dev_err(&indio_dev->dev, "GPADC mode\n");
190 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
191 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
193 dev_err(&indio_dev->dev, "TS pin restore\n");
198 mutex_unlock(&indio_dev->mlock);
204 * We rely on the machine's firmware to correctly setup the TS pin bias current
205 * at boot. This lists systems with broken fw where we need to set it ourselves.
207 static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
209 /* Lenovo Ideapad 100S (11 inch) */
211 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
212 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
214 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
219 static int axp288_adc_initialize(struct axp288_adc_info *info)
221 const struct dmi_system_id *bias_override;
222 int ret, adc_enable_val;
224 bias_override = dmi_first_match(axp288_adc_ts_bias_override);
226 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
227 AXP288_ADC_TS_BIAS_MASK,
228 (uintptr_t)bias_override->driver_data);
234 * Determine if the TS pin is enabled and set the TS current-source
237 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
241 if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
242 info->ts_enabled = true;
243 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
244 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
245 AXP288_ADC_TS_CURRENT_ON);
247 info->ts_enabled = false;
248 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
249 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
250 AXP288_ADC_TS_CURRENT_OFF);
255 /* Turn on the ADC for all channels except TS, leave TS as is */
256 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
257 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
260 static const struct iio_info axp288_adc_iio_info = {
261 .read_raw = &axp288_adc_read_raw,
262 .driver_module = THIS_MODULE,
265 static int axp288_adc_probe(struct platform_device *pdev)
268 struct axp288_adc_info *info;
269 struct iio_dev *indio_dev;
270 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
272 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
276 info = iio_priv(indio_dev);
277 info->irq = platform_get_irq(pdev, 0);
279 dev_err(&pdev->dev, "no irq resource?\n");
282 platform_set_drvdata(pdev, indio_dev);
283 info->regmap = axp20x->regmap;
285 * Set ADC to enabled state at all time, including system suspend.
286 * otherwise internal fuel gauge functionality may be affected.
288 ret = axp288_adc_initialize(info);
290 dev_err(&pdev->dev, "unable to enable ADC device\n");
294 indio_dev->dev.parent = &pdev->dev;
295 indio_dev->name = pdev->name;
296 indio_dev->channels = axp288_adc_channels;
297 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
298 indio_dev->info = &axp288_adc_iio_info;
299 indio_dev->modes = INDIO_DIRECT_MODE;
300 ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
304 ret = iio_device_register(indio_dev);
306 dev_err(&pdev->dev, "unable to register iio device\n");
307 goto err_array_unregister;
311 err_array_unregister:
312 iio_map_array_unregister(indio_dev);
317 static int axp288_adc_remove(struct platform_device *pdev)
319 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
321 iio_device_unregister(indio_dev);
322 iio_map_array_unregister(indio_dev);
327 static const struct platform_device_id axp288_adc_id_table[] = {
328 { .name = "axp288_adc" },
332 static struct platform_driver axp288_adc_driver = {
333 .probe = axp288_adc_probe,
334 .remove = axp288_adc_remove,
335 .id_table = axp288_adc_id_table,
337 .name = "axp288_adc",
341 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
343 module_platform_driver(axp288_adc_driver);
345 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
346 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
347 MODULE_LICENSE("GPL");