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 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(regmap, address, buf, 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(info->regmap, AXP288_ADC_TS_PIN_CTRL,
149				 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, 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(6000, 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					chan->address)) {
172			dev_err(&indio_dev->dev, "GPADC mode\n");
173			ret = -EINVAL;
174			break;
175		}
176		ret = axp288_adc_read_channel(val, chan->address, info->regmap);
177		if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
178						chan->address))
179			dev_err(&indio_dev->dev, "TS pin restore\n");
180		break;
181	default:
182		ret = -EINVAL;
183	}
184	mutex_unlock(&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(axp288_adc_ts_bias_override);
219	if (bias_override) {
220		ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
221					 AXP288_ADC_TS_BIAS_MASK,
222					 (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(info->regmap, AXP20X_ADC_EN1, &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(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(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_update_bits(info->regmap, AXP20X_ADC_EN1,
251				  AXP288_ADC_EN_MASK, 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(pdev->dev.parent);
264
265	indio_dev = devm_iio_device_alloc(&pdev->dev, 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(&pdev->dev, indio_dev, 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