1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
4 *
5 * Copyright (C) 2014 Intel Corporation
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 */
9
10#include <linux/dmi.h>
11#include <linux/module.h>
12#include <linux/mutex.h>
13#include <linux/kernel.h>
14#include <linux/device.h>
15#include <linux/regmap.h>
16#include <linux/mfd/axp20x.h>
17#include <linux/platform_device.h>
18
19#include <linux/iio/iio.h>
20#include <linux/iio/machine.h>
21#include <linux/iio/driver.h>
22
23/*
24 * This mask enables all ADCs except for the battery temp-sensor (TS), that is
25 * left as-is to avoid breaking charging on devices without a temp-sensor.
26 */
27#define AXP288_ADC_EN_MASK 0xF0
28#define AXP288_ADC_TS_ENABLE 0x01
29
30#define AXP288_ADC_TS_BIAS_MASK GENMASK(5, 4)
31#define AXP288_ADC_TS_BIAS_20UA (0 << 4)
32#define AXP288_ADC_TS_BIAS_40UA (1 << 4)
33#define AXP288_ADC_TS_BIAS_60UA (2 << 4)
34#define AXP288_ADC_TS_BIAS_80UA (3 << 4)
35#define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
36#define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
37#define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
38#define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0)
39#define AXP288_ADC_TS_CURRENT_ON (3 << 0)
40
41enum axp288_adc_id {
42 AXP288_ADC_TS,
43 AXP288_ADC_PMIC,
44 AXP288_ADC_GP,
45 AXP288_ADC_BATT_CHRG_I,
46 AXP288_ADC_BATT_DISCHRG_I,
47 AXP288_ADC_BATT_V,
48 AXP288_ADC_NR_CHAN,
49};
50
51struct axp288_adc_info {
52 int irq;
53 struct regmap *regmap;
54 /* lock to protect against multiple access to the device */
55 struct mutex lock;
56 bool ts_enabled;
57};
58
59static const struct iio_chan_spec axp288_adc_channels[] = {
60 {
61 .indexed = 1,
62 .type = IIO_TEMP,
63 .channel = 0,
64 .address = AXP288_TS_ADC_H,
65 .datasheet_name = "TS_PIN",
66 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
67 }, {
68 .indexed = 1,
69 .type = IIO_TEMP,
70 .channel = 1,
71 .address = AXP288_PMIC_ADC_H,
72 .datasheet_name = "PMIC_TEMP",
73 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
74 }, {
75 .indexed = 1,
76 .type = IIO_TEMP,
77 .channel = 2,
78 .address = AXP288_GP_ADC_H,
79 .datasheet_name = "GPADC",
80 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
81 }, {
82 .indexed = 1,
83 .type = IIO_CURRENT,
84 .channel = 3,
85 .address = AXP20X_BATT_CHRG_I_H,
86 .datasheet_name = "BATT_CHG_I",
87 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
88 }, {
89 .indexed = 1,
90 .type = IIO_CURRENT,
91 .channel = 4,
92 .address = AXP20X_BATT_DISCHRG_I_H,
93 .datasheet_name = "BATT_DISCHRG_I",
94 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
95 }, {
96 .indexed = 1,
97 .type = IIO_VOLTAGE,
98 .channel = 5,
99 .address = AXP20X_BATT_V_H,
100 .datasheet_name = "BATT_V",
101 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
102 },
103};
104
105/* for consumer drivers */
106static const struct iio_map axp288_adc_default_maps[] = {
107 IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
108 IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
109 IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
110 IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
111 IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
112 IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
113 { }
114};
115
116static int axp288_adc_read_channel(int *val, unsigned long address,
117 struct regmap *regmap)
118{
119 u8 buf[2];
120
121 if (regmap_bulk_read(map: regmap, reg: address, val: buf, val_count: 2))
122 return -EIO;
123 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
124
125 return IIO_VAL_INT;
126}
127
128/*
129 * The current-source used for the battery temp-sensor (TS) is shared
130 * with the GPADC. For proper fuel-gauge and charger operation the TS
131 * current-source needs to be permanently on. But to read the GPADC we
132 * need to temporary switch the TS current-source to ondemand, so that
133 * the GPADC can use it, otherwise we will always read an all 0 value.
134 */
135static int axp288_adc_set_ts(struct axp288_adc_info *info,
136 unsigned int mode, unsigned long address)
137{
138 int ret;
139
140 /* No need to switch the current-source if the TS pin is disabled */
141 if (!info->ts_enabled)
142 return 0;
143
144 /* Channels other than GPADC do not need the current source */
145 if (address != AXP288_GP_ADC_H)
146 return 0;
147
148 ret = regmap_update_bits(map: info->regmap, AXP288_ADC_TS_PIN_CTRL,
149 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, val: mode);
150 if (ret)
151 return ret;
152
153 /* When switching to the GPADC pin give things some time to settle */
154 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
155 usleep_range(min: 6000, max: 10000);
156
157 return 0;
158}
159
160static int axp288_adc_read_raw(struct iio_dev *indio_dev,
161 struct iio_chan_spec const *chan,
162 int *val, int *val2, long mask)
163{
164 int ret;
165 struct axp288_adc_info *info = iio_priv(indio_dev);
166
167 mutex_lock(&info->lock);
168 switch (mask) {
169 case IIO_CHAN_INFO_RAW:
170 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
171 address: chan->address)) {
172 dev_err(&indio_dev->dev, "GPADC mode\n");
173 ret = -EINVAL;
174 break;
175 }
176 ret = axp288_adc_read_channel(val, address: chan->address, regmap: info->regmap);
177 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
178 address: chan->address))
179 dev_err(&indio_dev->dev, "TS pin restore\n");
180 break;
181 default:
182 ret = -EINVAL;
183 }
184 mutex_unlock(lock: &info->lock);
185
186 return ret;
187}
188
189/*
190 * We rely on the machine's firmware to correctly setup the TS pin bias current
191 * at boot. This lists systems with broken fw where we need to set it ourselves.
192 */
193static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
194 {
195 /* Lenovo Ideapad 100S (11 inch) */
196 .matches = {
197 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
198 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
199 },
200 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
201 },
202 {
203 /* Nuvision Solo 10 Draw */
204 .matches = {
205 DMI_MATCH(DMI_SYS_VENDOR, "TMAX"),
206 DMI_MATCH(DMI_PRODUCT_NAME, "TM101W610L"),
207 },
208 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
209 },
210 { }
211};
212
213static int axp288_adc_initialize(struct axp288_adc_info *info)
214{
215 const struct dmi_system_id *bias_override;
216 int ret, adc_enable_val;
217
218 bias_override = dmi_first_match(list: axp288_adc_ts_bias_override);
219 if (bias_override) {
220 ret = regmap_update_bits(map: info->regmap, AXP288_ADC_TS_PIN_CTRL,
221 AXP288_ADC_TS_BIAS_MASK,
222 val: (uintptr_t)bias_override->driver_data);
223 if (ret)
224 return ret;
225 }
226
227 /*
228 * Determine if the TS pin is enabled and set the TS current-source
229 * accordingly.
230 */
231 ret = regmap_read(map: info->regmap, AXP20X_ADC_EN1, val: &adc_enable_val);
232 if (ret)
233 return ret;
234
235 if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
236 info->ts_enabled = true;
237 ret = regmap_update_bits(map: info->regmap, AXP288_ADC_TS_PIN_CTRL,
238 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
239 AXP288_ADC_TS_CURRENT_ON);
240 } else {
241 info->ts_enabled = false;
242 ret = regmap_update_bits(map: info->regmap, AXP288_ADC_TS_PIN_CTRL,
243 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
244 AXP288_ADC_TS_CURRENT_OFF);
245 }
246 if (ret)
247 return ret;
248
249 /* Turn on the ADC for all channels except TS, leave TS as is */
250 return regmap_set_bits(map: info->regmap, AXP20X_ADC_EN1,
251 AXP288_ADC_EN_MASK);
252}
253
254static const struct iio_info axp288_adc_iio_info = {
255 .read_raw = &axp288_adc_read_raw,
256};
257
258static int axp288_adc_probe(struct platform_device *pdev)
259{
260 int ret;
261 struct axp288_adc_info *info;
262 struct iio_dev *indio_dev;
263 struct axp20x_dev *axp20x = dev_get_drvdata(dev: pdev->dev.parent);
264
265 indio_dev = devm_iio_device_alloc(parent: &pdev->dev, sizeof_priv: sizeof(*info));
266 if (!indio_dev)
267 return -ENOMEM;
268
269 info = iio_priv(indio_dev);
270 info->irq = platform_get_irq(pdev, 0);
271 if (info->irq < 0)
272 return info->irq;
273
274 info->regmap = axp20x->regmap;
275 /*
276 * Set ADC to enabled state at all time, including system suspend.
277 * otherwise internal fuel gauge functionality may be affected.
278 */
279 ret = axp288_adc_initialize(info);
280 if (ret) {
281 dev_err(&pdev->dev, "unable to enable ADC device\n");
282 return ret;
283 }
284
285 indio_dev->name = pdev->name;
286 indio_dev->channels = axp288_adc_channels;
287 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
288 indio_dev->info = &axp288_adc_iio_info;
289 indio_dev->modes = INDIO_DIRECT_MODE;
290
291 ret = devm_iio_map_array_register(dev: &pdev->dev, indio_dev, maps: axp288_adc_default_maps);
292 if (ret < 0)
293 return ret;
294
295 mutex_init(&info->lock);
296
297 return devm_iio_device_register(&pdev->dev, indio_dev);
298}
299
300static const struct platform_device_id axp288_adc_id_table[] = {
301 { .name = "axp288_adc" },
302 { }
303};
304
305static struct platform_driver axp288_adc_driver = {
306 .probe = axp288_adc_probe,
307 .id_table = axp288_adc_id_table,
308 .driver = {
309 .name = "axp288_adc",
310 },
311};
312
313MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
314
315module_platform_driver(axp288_adc_driver);
316
317MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
318MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
319MODULE_LICENSE("GPL");
320

source code of linux/drivers/iio/adc/axp288_adc.c