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/kernel.h>
13 #include <linux/device.h>
14 #include <linux/regmap.h>
15 #include <linux/mfd/axp20x.h>
16 #include <linux/platform_device.h>
17
18 #include <linux/iio/iio.h>
19 #include <linux/iio/machine.h>
20 #include <linux/iio/driver.h>
21
22 /*
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.
25 */
26 #define AXP288_ADC_EN_MASK 0xF0
27 #define AXP288_ADC_TS_ENABLE 0x01
28
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)
39
40 enum axp288_adc_id {
41 AXP288_ADC_TS,
42 AXP288_ADC_PMIC,
43 AXP288_ADC_GP,
44 AXP288_ADC_BATT_CHRG_I,
45 AXP288_ADC_BATT_DISCHRG_I,
46 AXP288_ADC_BATT_V,
47 AXP288_ADC_NR_CHAN,
48 };
49
50 struct axp288_adc_info {
51 int irq;
52 struct regmap *regmap;
53 bool ts_enabled;
54 };
55
56 static const struct iio_chan_spec axp288_adc_channels[] = {
57 {
58 .indexed = 1,
59 .type = IIO_TEMP,
60 .channel = 0,
61 .address = AXP288_TS_ADC_H,
62 .datasheet_name = "TS_PIN",
63 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
64 }, {
65 .indexed = 1,
66 .type = IIO_TEMP,
67 .channel = 1,
68 .address = AXP288_PMIC_ADC_H,
69 .datasheet_name = "PMIC_TEMP",
70 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
71 }, {
72 .indexed = 1,
73 .type = IIO_TEMP,
74 .channel = 2,
75 .address = AXP288_GP_ADC_H,
76 .datasheet_name = "GPADC",
77 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
78 }, {
79 .indexed = 1,
80 .type = IIO_CURRENT,
81 .channel = 3,
82 .address = AXP20X_BATT_CHRG_I_H,
83 .datasheet_name = "BATT_CHG_I",
84 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
85 }, {
86 .indexed = 1,
87 .type = IIO_CURRENT,
88 .channel = 4,
89 .address = AXP20X_BATT_DISCHRG_I_H,
90 .datasheet_name = "BATT_DISCHRG_I",
91 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
92 }, {
93 .indexed = 1,
94 .type = IIO_VOLTAGE,
95 .channel = 5,
96 .address = AXP20X_BATT_V_H,
97 .datasheet_name = "BATT_V",
98 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
99 },
100 };
101
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"),
110 {},
111 };
112
axp288_adc_read_channel(int * val,unsigned long address,struct regmap * regmap)113 static int axp288_adc_read_channel(int *val, unsigned long address,
114 struct regmap *regmap)
115 {
116 u8 buf[2];
117
118 if (regmap_bulk_read(regmap, address, buf, 2))
119 return -EIO;
120 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
121
122 return IIO_VAL_INT;
123 }
124
125 /*
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.
131 */
axp288_adc_set_ts(struct axp288_adc_info * info,unsigned int mode,unsigned long address)132 static int axp288_adc_set_ts(struct axp288_adc_info *info,
133 unsigned int mode, unsigned long address)
134 {
135 int ret;
136
137 /* No need to switch the current-source if the TS pin is disabled */
138 if (!info->ts_enabled)
139 return 0;
140
141 /* Channels other than GPADC do not need the current source */
142 if (address != AXP288_GP_ADC_H)
143 return 0;
144
145 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
146 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
147 if (ret)
148 return ret;
149
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);
153
154 return 0;
155 }
156
axp288_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)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)
160 {
161 int ret;
162 struct axp288_adc_info *info = iio_priv(indio_dev);
163
164 mutex_lock(&indio_dev->mlock);
165 switch (mask) {
166 case IIO_CHAN_INFO_RAW:
167 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
168 chan->address)) {
169 dev_err(&indio_dev->dev, "GPADC mode\n");
170 ret = -EINVAL;
171 break;
172 }
173 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
174 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
175 chan->address))
176 dev_err(&indio_dev->dev, "TS pin restore\n");
177 break;
178 default:
179 ret = -EINVAL;
180 }
181 mutex_unlock(&indio_dev->mlock);
182
183 return ret;
184 }
185
186 /*
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.
189 */
190 static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
191 {
192 /* Lenovo Ideapad 100S (11 inch) */
193 .matches = {
194 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
195 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
196 },
197 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
198 },
199 {
200 /* Nuvision Solo 10 Draw */
201 .matches = {
202 DMI_MATCH(DMI_SYS_VENDOR, "TMAX"),
203 DMI_MATCH(DMI_PRODUCT_NAME, "TM101W610L"),
204 },
205 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
206 },
207 {}
208 };
209
axp288_adc_initialize(struct axp288_adc_info * info)210 static int axp288_adc_initialize(struct axp288_adc_info *info)
211 {
212 const struct dmi_system_id *bias_override;
213 int ret, adc_enable_val;
214
215 bias_override = dmi_first_match(axp288_adc_ts_bias_override);
216 if (bias_override) {
217 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
218 AXP288_ADC_TS_BIAS_MASK,
219 (uintptr_t)bias_override->driver_data);
220 if (ret)
221 return ret;
222 }
223
224 /*
225 * Determine if the TS pin is enabled and set the TS current-source
226 * accordingly.
227 */
228 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
229 if (ret)
230 return ret;
231
232 if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
233 info->ts_enabled = true;
234 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
235 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
236 AXP288_ADC_TS_CURRENT_ON);
237 } else {
238 info->ts_enabled = false;
239 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
240 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
241 AXP288_ADC_TS_CURRENT_OFF);
242 }
243 if (ret)
244 return ret;
245
246 /* Turn on the ADC for all channels except TS, leave TS as is */
247 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
248 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
249 }
250
251 static const struct iio_info axp288_adc_iio_info = {
252 .read_raw = &axp288_adc_read_raw,
253 };
254
axp288_adc_probe(struct platform_device * pdev)255 static int axp288_adc_probe(struct platform_device *pdev)
256 {
257 int ret;
258 struct axp288_adc_info *info;
259 struct iio_dev *indio_dev;
260 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
261
262 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
263 if (!indio_dev)
264 return -ENOMEM;
265
266 info = iio_priv(indio_dev);
267 info->irq = platform_get_irq(pdev, 0);
268 if (info->irq < 0)
269 return info->irq;
270
271 info->regmap = axp20x->regmap;
272 /*
273 * Set ADC to enabled state at all time, including system suspend.
274 * otherwise internal fuel gauge functionality may be affected.
275 */
276 ret = axp288_adc_initialize(info);
277 if (ret) {
278 dev_err(&pdev->dev, "unable to enable ADC device\n");
279 return ret;
280 }
281
282 indio_dev->name = pdev->name;
283 indio_dev->channels = axp288_adc_channels;
284 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
285 indio_dev->info = &axp288_adc_iio_info;
286 indio_dev->modes = INDIO_DIRECT_MODE;
287
288 ret = devm_iio_map_array_register(&pdev->dev, indio_dev, axp288_adc_default_maps);
289 if (ret < 0)
290 return ret;
291
292 return devm_iio_device_register(&pdev->dev, indio_dev);
293 }
294
295 static const struct platform_device_id axp288_adc_id_table[] = {
296 { .name = "axp288_adc" },
297 {},
298 };
299
300 static struct platform_driver axp288_adc_driver = {
301 .probe = axp288_adc_probe,
302 .id_table = axp288_adc_id_table,
303 .driver = {
304 .name = "axp288_adc",
305 },
306 };
307
308 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
309
310 module_platform_driver(axp288_adc_driver);
311
312 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
313 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
314 MODULE_LICENSE("GPL");
315