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 /* for consumer drivers */
112 static struct iio_map axp288_adc_default_maps[] = {
113 IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
114 IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
115 IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
116 IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
117 IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
118 IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
119 {},
120 };
121
axp288_adc_read_channel(int * val,unsigned long address,struct regmap * regmap)122 static int axp288_adc_read_channel(int *val, unsigned long address,
123 struct regmap *regmap)
124 {
125 u8 buf[2];
126
127 if (regmap_bulk_read(regmap, address, buf, 2))
128 return -EIO;
129 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
130
131 return IIO_VAL_INT;
132 }
133
134 /*
135 * The current-source used for the battery temp-sensor (TS) is shared
136 * with the GPADC. For proper fuel-gauge and charger operation the TS
137 * current-source needs to be permanently on. But to read the GPADC we
138 * need to temporary switch the TS current-source to ondemand, so that
139 * the GPADC can use it, otherwise we will always read an all 0 value.
140 */
axp288_adc_set_ts(struct axp288_adc_info * info,unsigned int mode,unsigned long address)141 static int axp288_adc_set_ts(struct axp288_adc_info *info,
142 unsigned int mode, unsigned long address)
143 {
144 int ret;
145
146 /* No need to switch the current-source if the TS pin is disabled */
147 if (!info->ts_enabled)
148 return 0;
149
150 /* Channels other than GPADC do not need the current source */
151 if (address != AXP288_GP_ADC_H)
152 return 0;
153
154 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
155 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
156 if (ret)
157 return ret;
158
159 /* When switching to the GPADC pin give things some time to settle */
160 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
161 usleep_range(6000, 10000);
162
163 return 0;
164 }
165
axp288_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)166 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
167 struct iio_chan_spec const *chan,
168 int *val, int *val2, long mask)
169 {
170 int ret;
171 struct axp288_adc_info *info = iio_priv(indio_dev);
172
173 mutex_lock(&indio_dev->mlock);
174 switch (mask) {
175 case IIO_CHAN_INFO_RAW:
176 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
177 chan->address)) {
178 dev_err(&indio_dev->dev, "GPADC mode\n");
179 ret = -EINVAL;
180 break;
181 }
182 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
183 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
184 chan->address))
185 dev_err(&indio_dev->dev, "TS pin restore\n");
186 break;
187 default:
188 ret = -EINVAL;
189 }
190 mutex_unlock(&indio_dev->mlock);
191
192 return ret;
193 }
194
195 /*
196 * We rely on the machine's firmware to correctly setup the TS pin bias current
197 * at boot. This lists systems with broken fw where we need to set it ourselves.
198 */
199 static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
200 {
201 /* Lenovo Ideapad 100S (11 inch) */
202 .matches = {
203 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
204 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
205 },
206 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
207 },
208 {}
209 };
210
axp288_adc_initialize(struct axp288_adc_info * info)211 static int axp288_adc_initialize(struct axp288_adc_info *info)
212 {
213 const struct dmi_system_id *bias_override;
214 int ret, adc_enable_val;
215
216 bias_override = dmi_first_match(axp288_adc_ts_bias_override);
217 if (bias_override) {
218 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
219 AXP288_ADC_TS_BIAS_MASK,
220 (uintptr_t)bias_override->driver_data);
221 if (ret)
222 return ret;
223 }
224
225 /*
226 * Determine if the TS pin is enabled and set the TS current-source
227 * accordingly.
228 */
229 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
230 if (ret)
231 return ret;
232
233 if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
234 info->ts_enabled = true;
235 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
236 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
237 AXP288_ADC_TS_CURRENT_ON);
238 } else {
239 info->ts_enabled = false;
240 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
241 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
242 AXP288_ADC_TS_CURRENT_OFF);
243 }
244 if (ret)
245 return ret;
246
247 /* Turn on the ADC for all channels except TS, leave TS as is */
248 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
249 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
250 }
251
252 static const struct iio_info axp288_adc_iio_info = {
253 .read_raw = &axp288_adc_read_raw,
254 };
255
axp288_adc_probe(struct platform_device * pdev)256 static int axp288_adc_probe(struct platform_device *pdev)
257 {
258 int ret;
259 struct axp288_adc_info *info;
260 struct iio_dev *indio_dev;
261 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
262
263 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
264 if (!indio_dev)
265 return -ENOMEM;
266
267 info = iio_priv(indio_dev);
268 info->irq = platform_get_irq(pdev, 0);
269 if (info->irq < 0) {
270 dev_err(&pdev->dev, "no irq resource?\n");
271 return info->irq;
272 }
273 platform_set_drvdata(pdev, indio_dev);
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->dev.parent = &pdev->dev;
286 indio_dev->name = pdev->name;
287 indio_dev->channels = axp288_adc_channels;
288 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
289 indio_dev->info = &axp288_adc_iio_info;
290 indio_dev->modes = INDIO_DIRECT_MODE;
291 ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
292 if (ret < 0)
293 return ret;
294
295 ret = iio_device_register(indio_dev);
296 if (ret < 0) {
297 dev_err(&pdev->dev, "unable to register iio device\n");
298 goto err_array_unregister;
299 }
300 return 0;
301
302 err_array_unregister:
303 iio_map_array_unregister(indio_dev);
304
305 return ret;
306 }
307
axp288_adc_remove(struct platform_device * pdev)308 static int axp288_adc_remove(struct platform_device *pdev)
309 {
310 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
311
312 iio_device_unregister(indio_dev);
313 iio_map_array_unregister(indio_dev);
314
315 return 0;
316 }
317
318 static const struct platform_device_id axp288_adc_id_table[] = {
319 { .name = "axp288_adc" },
320 {},
321 };
322
323 static struct platform_driver axp288_adc_driver = {
324 .probe = axp288_adc_probe,
325 .remove = axp288_adc_remove,
326 .id_table = axp288_adc_id_table,
327 .driver = {
328 .name = "axp288_adc",
329 },
330 };
331
332 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
333
334 module_platform_driver(axp288_adc_driver);
335
336 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
337 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
338 MODULE_LICENSE("GPL");
339