1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support for Vishay VCNL3020 proximity sensor on i2c bus.
4 * Based on Vishay VCNL4000 driver code.
5 *
6 * TODO: interrupts.
7 */
8
9#include <linux/module.h>
10#include <linux/i2c.h>
11#include <linux/err.h>
12#include <linux/delay.h>
13#include <linux/regmap.h>
14
15#include <linux/iio/iio.h>
16#include <linux/iio/sysfs.h>
17
18#define VCNL3020_PROD_ID	0x21
19
20#define VCNL_COMMAND		0x80 /* Command register */
21#define VCNL_PROD_REV		0x81 /* Product ID and Revision ID */
22#define VCNL_PROXIMITY_RATE	0x82 /* Rate of Proximity Measurement */
23#define VCNL_LED_CURRENT	0x83 /* IR LED current for proximity mode */
24#define VCNL_PS_RESULT_HI	0x87 /* Proximity result register, MSB */
25#define VCNL_PS_RESULT_LO	0x88 /* Proximity result register, LSB */
26#define VCNL_PS_ICR		0x89 /* Interrupt Control Register */
27#define VCNL_PS_LO_THR_HI	0x8a /* High byte of low threshold value */
28#define VCNL_PS_LO_THR_LO	0x8b /* Low byte of low threshold value */
29#define VCNL_PS_HI_THR_HI	0x8c /* High byte of high threshold value */
30#define VCNL_PS_HI_THR_LO	0x8d /* Low byte of high threshold value */
31#define VCNL_ISR		0x8e /* Interrupt Status Register */
32#define VCNL_PS_MOD_ADJ		0x8f /* Proximity Modulator Timing Adjustment */
33
34/* Bit masks for COMMAND register */
35#define VCNL_PS_RDY		BIT(5) /* proximity data ready? */
36#define VCNL_PS_OD		BIT(3) /* start on-demand proximity
37					* measurement
38					*/
39
40#define VCNL_ON_DEMAND_TIMEOUT_US	100000
41#define VCNL_POLL_US			20000
42
43/**
44 * struct vcnl3020_data - vcnl3020 specific data.
45 * @regmap:	device register map.
46 * @dev:	vcnl3020 device.
47 * @rev:	revision id.
48 * @lock:	lock for protecting access to device hardware registers.
49 */
50struct vcnl3020_data {
51	struct regmap *regmap;
52	struct device *dev;
53	u8 rev;
54	struct mutex lock;
55};
56
57/**
58 * struct vcnl3020_property - vcnl3020 property.
59 * @name:	property name.
60 * @reg:	i2c register offset.
61 * @conversion_func:	conversion function.
62 */
63struct vcnl3020_property {
64	const char *name;
65	u32 reg;
66	u32 (*conversion_func)(u32 *val);
67};
68
69static u32 microamp_to_reg(u32 *val)
70{
71	/*
72	 * An example of conversion from uA to reg val:
73	 * 200000 uA == 200 mA == 20
74	 */
75	return *val /= 10000;
76};
77
78static struct vcnl3020_property vcnl3020_led_current_property = {
79	.name = "vishay,led-current-microamp",
80	.reg = VCNL_LED_CURRENT,
81	.conversion_func = microamp_to_reg,
82};
83
84static int vcnl3020_get_and_apply_property(struct vcnl3020_data *data,
85					   struct vcnl3020_property prop)
86{
87	int rc;
88	u32 val;
89
90	rc = device_property_read_u32(data->dev, prop.name, &val);
91	if (rc)
92		return 0;
93
94	if (prop.conversion_func)
95		prop.conversion_func(&val);
96
97	rc = regmap_write(data->regmap, prop.reg, val);
98	if (rc) {
99		dev_err(data->dev, "Error (%d) setting property (%s)\n",
100			rc, prop.name);
101	}
102
103	return rc;
104}
105
106static int vcnl3020_init(struct vcnl3020_data *data)
107{
108	int rc;
109	unsigned int reg;
110
111	rc = regmap_read(data->regmap, VCNL_PROD_REV, &reg);
112	if (rc) {
113		dev_err(data->dev,
114			"Error (%d) reading product revision\n", rc);
115		return rc;
116	}
117
118	if (reg != VCNL3020_PROD_ID) {
119		dev_err(data->dev,
120			"Product id (%x) did not match vcnl3020 (%x)\n", reg,
121			VCNL3020_PROD_ID);
122		return -ENODEV;
123	}
124
125	data->rev = reg;
126	mutex_init(&data->lock);
127
128	return vcnl3020_get_and_apply_property(data,
129					       vcnl3020_led_current_property);
130};
131
132static int vcnl3020_measure_proximity(struct vcnl3020_data *data, int *val)
133{
134	int rc;
135	unsigned int reg;
136	__be16 res;
137
138	mutex_lock(&data->lock);
139
140	rc = regmap_write(data->regmap, VCNL_COMMAND, VCNL_PS_OD);
141	if (rc)
142		goto err_unlock;
143
144	/* wait for data to become ready */
145	rc = regmap_read_poll_timeout(data->regmap, VCNL_COMMAND, reg,
146				      reg & VCNL_PS_RDY, VCNL_POLL_US,
147				      VCNL_ON_DEMAND_TIMEOUT_US);
148	if (rc) {
149		dev_err(data->dev,
150			"Error (%d) reading vcnl3020 command register\n", rc);
151		goto err_unlock;
152	}
153
154	/* high & low result bytes read */
155	rc = regmap_bulk_read(data->regmap, VCNL_PS_RESULT_HI, &res,
156			      sizeof(res));
157	if (rc)
158		goto err_unlock;
159
160	*val = be16_to_cpu(res);
161
162err_unlock:
163	mutex_unlock(&data->lock);
164
165	return rc;
166}
167
168static const struct iio_chan_spec vcnl3020_channels[] = {
169	{
170		.type = IIO_PROXIMITY,
171		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
172	},
173};
174
175static int vcnl3020_read_raw(struct iio_dev *indio_dev,
176			     struct iio_chan_spec const *chan, int *val,
177			     int *val2, long mask)
178{
179	int rc;
180	struct vcnl3020_data *data = iio_priv(indio_dev);
181
182	switch (mask) {
183	case IIO_CHAN_INFO_RAW:
184		rc = vcnl3020_measure_proximity(data, val);
185		if (rc)
186			return rc;
187		return IIO_VAL_INT;
188	default:
189		return -EINVAL;
190	}
191}
192
193static const struct iio_info vcnl3020_info = {
194	.read_raw = vcnl3020_read_raw,
195};
196
197static const struct regmap_config vcnl3020_regmap_config = {
198	.reg_bits	= 8,
199	.val_bits	= 8,
200	.max_register	= VCNL_PS_MOD_ADJ,
201};
202
203static int vcnl3020_probe(struct i2c_client *client)
204{
205	struct vcnl3020_data *data;
206	struct iio_dev *indio_dev;
207	struct regmap *regmap;
208	int rc;
209
210	regmap = devm_regmap_init_i2c(client, &vcnl3020_regmap_config);
211	if (IS_ERR(regmap)) {
212		dev_err(&client->dev, "regmap_init failed\n");
213		return PTR_ERR(regmap);
214	}
215
216	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
217	if (!indio_dev)
218		return -ENOMEM;
219
220	data = iio_priv(indio_dev);
221	i2c_set_clientdata(client, indio_dev);
222	data->regmap = regmap;
223	data->dev = &client->dev;
224
225	rc = vcnl3020_init(data);
226	if (rc)
227		return rc;
228
229	indio_dev->info = &vcnl3020_info;
230	indio_dev->channels = vcnl3020_channels;
231	indio_dev->num_channels = ARRAY_SIZE(vcnl3020_channels);
232	indio_dev->name = "vcnl3020";
233	indio_dev->modes = INDIO_DIRECT_MODE;
234
235	return devm_iio_device_register(&client->dev, indio_dev);
236}
237
238static const struct of_device_id vcnl3020_of_match[] = {
239	{
240		.compatible = "vishay,vcnl3020",
241	},
242	{}
243};
244MODULE_DEVICE_TABLE(of, vcnl3020_of_match);
245
246static struct i2c_driver vcnl3020_driver = {
247	.driver = {
248		.name   = "vcnl3020",
249		.of_match_table = vcnl3020_of_match,
250	},
251	.probe_new  = vcnl3020_probe,
252};
253module_i2c_driver(vcnl3020_driver);
254
255MODULE_AUTHOR("Ivan Mikhaylov <i.mikhaylov@yadro.com>");
256MODULE_DESCRIPTION("Vishay VCNL3020 proximity sensor driver");
257MODULE_LICENSE("GPL");
258