1 /*
2 * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
3 *
4 * Copyright (C) 2014 Intel Corporation
5 *
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 *
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.
11 *
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.
16 *
17 */
18
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>
26
27 #include <linux/iio/iio.h>
28 #include <linux/iio/machine.h>
29 #include <linux/iio/driver.h>
30
31 /*
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.
34 */
35 #define AXP288_ADC_EN_MASK 0xF0
36 #define AXP288_ADC_TS_ENABLE 0x01
37
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)
48
49 enum axp288_adc_id {
50 AXP288_ADC_TS,
51 AXP288_ADC_PMIC,
52 AXP288_ADC_GP,
53 AXP288_ADC_BATT_CHRG_I,
54 AXP288_ADC_BATT_DISCHRG_I,
55 AXP288_ADC_BATT_V,
56 AXP288_ADC_NR_CHAN,
57 };
58
59 struct axp288_adc_info {
60 int irq;
61 struct regmap *regmap;
62 bool ts_enabled;
63 };
64
65 static const struct iio_chan_spec axp288_adc_channels[] = {
66 {
67 .indexed = 1,
68 .type = IIO_TEMP,
69 .channel = 0,
70 .address = AXP288_TS_ADC_H,
71 .datasheet_name = "TS_PIN",
72 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
73 }, {
74 .indexed = 1,
75 .type = IIO_TEMP,
76 .channel = 1,
77 .address = AXP288_PMIC_ADC_H,
78 .datasheet_name = "PMIC_TEMP",
79 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
80 }, {
81 .indexed = 1,
82 .type = IIO_TEMP,
83 .channel = 2,
84 .address = AXP288_GP_ADC_H,
85 .datasheet_name = "GPADC",
86 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
87 }, {
88 .indexed = 1,
89 .type = IIO_CURRENT,
90 .channel = 3,
91 .address = AXP20X_BATT_CHRG_I_H,
92 .datasheet_name = "BATT_CHG_I",
93 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
94 }, {
95 .indexed = 1,
96 .type = IIO_CURRENT,
97 .channel = 4,
98 .address = AXP20X_BATT_DISCHRG_I_H,
99 .datasheet_name = "BATT_DISCHRG_I",
100 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
101 }, {
102 .indexed = 1,
103 .type = IIO_VOLTAGE,
104 .channel = 5,
105 .address = AXP20X_BATT_V_H,
106 .datasheet_name = "BATT_V",
107 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
108 },
109 };
110
111 #define AXP288_ADC_MAP(_adc_channel_label, _consumer_dev_name, \
112 _consumer_channel) \
113 { \
114 .adc_channel_label = _adc_channel_label, \
115 .consumer_dev_name = _consumer_dev_name, \
116 .consumer_channel = _consumer_channel, \
117 }
118
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"),
127 {},
128 };
129
axp288_adc_read_channel(int * val,unsigned long address,struct regmap * regmap)130 static int axp288_adc_read_channel(int *val, unsigned long address,
131 struct regmap *regmap)
132 {
133 u8 buf[2];
134
135 if (regmap_bulk_read(regmap, address, buf, 2))
136 return -EIO;
137 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
138
139 return IIO_VAL_INT;
140 }
141
142 /*
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.
148 */
axp288_adc_set_ts(struct axp288_adc_info * info,unsigned int mode,unsigned long address)149 static int axp288_adc_set_ts(struct axp288_adc_info *info,
150 unsigned int mode, unsigned long address)
151 {
152 int ret;
153
154 /* No need to switch the current-source if the TS pin is disabled */
155 if (!info->ts_enabled)
156 return 0;
157
158 /* Channels other than GPADC do not need the current source */
159 if (address != AXP288_GP_ADC_H)
160 return 0;
161
162 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
163 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
164 if (ret)
165 return ret;
166
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);
170
171 return 0;
172 }
173
axp288_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)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)
177 {
178 int ret;
179 struct axp288_adc_info *info = iio_priv(indio_dev);
180
181 mutex_lock(&indio_dev->mlock);
182 switch (mask) {
183 case IIO_CHAN_INFO_RAW:
184 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
185 chan->address)) {
186 dev_err(&indio_dev->dev, "GPADC mode\n");
187 ret = -EINVAL;
188 break;
189 }
190 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
191 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
192 chan->address))
193 dev_err(&indio_dev->dev, "TS pin restore\n");
194 break;
195 default:
196 ret = -EINVAL;
197 }
198 mutex_unlock(&indio_dev->mlock);
199
200 return ret;
201 }
202
203 /*
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.
206 */
207 static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
208 {
209 /* Lenovo Ideapad 100S (11 inch) */
210 .matches = {
211 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
212 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
213 },
214 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
215 },
216 {}
217 };
218
axp288_adc_initialize(struct axp288_adc_info * info)219 static int axp288_adc_initialize(struct axp288_adc_info *info)
220 {
221 const struct dmi_system_id *bias_override;
222 int ret, adc_enable_val;
223
224 bias_override = dmi_first_match(axp288_adc_ts_bias_override);
225 if (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);
229 if (ret)
230 return ret;
231 }
232
233 /*
234 * Determine if the TS pin is enabled and set the TS current-source
235 * accordingly.
236 */
237 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
238 if (ret)
239 return ret;
240
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);
246 } else {
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);
251 }
252 if (ret)
253 return ret;
254
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);
258 }
259
260 static const struct iio_info axp288_adc_iio_info = {
261 .read_raw = &axp288_adc_read_raw,
262 .driver_module = THIS_MODULE,
263 };
264
axp288_adc_probe(struct platform_device * pdev)265 static int axp288_adc_probe(struct platform_device *pdev)
266 {
267 int ret;
268 struct axp288_adc_info *info;
269 struct iio_dev *indio_dev;
270 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
271
272 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
273 if (!indio_dev)
274 return -ENOMEM;
275
276 info = iio_priv(indio_dev);
277 info->irq = platform_get_irq(pdev, 0);
278 if (info->irq < 0) {
279 dev_err(&pdev->dev, "no irq resource?\n");
280 return info->irq;
281 }
282 platform_set_drvdata(pdev, indio_dev);
283 info->regmap = axp20x->regmap;
284 /*
285 * Set ADC to enabled state at all time, including system suspend.
286 * otherwise internal fuel gauge functionality may be affected.
287 */
288 ret = axp288_adc_initialize(info);
289 if (ret) {
290 dev_err(&pdev->dev, "unable to enable ADC device\n");
291 return ret;
292 }
293
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);
301 if (ret < 0)
302 return ret;
303
304 ret = iio_device_register(indio_dev);
305 if (ret < 0) {
306 dev_err(&pdev->dev, "unable to register iio device\n");
307 goto err_array_unregister;
308 }
309 return 0;
310
311 err_array_unregister:
312 iio_map_array_unregister(indio_dev);
313
314 return ret;
315 }
316
axp288_adc_remove(struct platform_device * pdev)317 static int axp288_adc_remove(struct platform_device *pdev)
318 {
319 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
320
321 iio_device_unregister(indio_dev);
322 iio_map_array_unregister(indio_dev);
323
324 return 0;
325 }
326
327 static const struct platform_device_id axp288_adc_id_table[] = {
328 { .name = "axp288_adc" },
329 {},
330 };
331
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,
336 .driver = {
337 .name = "axp288_adc",
338 },
339 };
340
341 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
342
343 module_platform_driver(axp288_adc_driver);
344
345 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
346 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
347 MODULE_LICENSE("GPL");
348