xref: /openbmc/linux/drivers/iio/proximity/vcnl3020.c (revision e15a5365)
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  */
50 struct 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  */
63 struct vcnl3020_property {
64 	const char *name;
65 	u32 reg;
66 	u32 (*conversion_func)(u32 *val);
67 };
68 
69 static 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 
78 static 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 
84 static 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 
106 static 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 
132 static 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 
162 err_unlock:
163 	mutex_unlock(&data->lock);
164 
165 	return rc;
166 }
167 
168 static const struct iio_chan_spec vcnl3020_channels[] = {
169 	{
170 		.type = IIO_PROXIMITY,
171 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
172 	},
173 };
174 
175 static 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 
193 static const struct iio_info vcnl3020_info = {
194 	.read_raw = vcnl3020_read_raw,
195 };
196 
197 static const struct regmap_config vcnl3020_regmap_config = {
198 	.reg_bits	= 8,
199 	.val_bits	= 8,
200 	.max_register	= VCNL_PS_MOD_ADJ,
201 };
202 
203 static 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 
238 static const struct of_device_id vcnl3020_of_match[] = {
239 	{
240 		.compatible = "vishay,vcnl3020",
241 	},
242 	{}
243 };
244 MODULE_DEVICE_TABLE(of, vcnl3020_of_match);
245 
246 static struct i2c_driver vcnl3020_driver = {
247 	.driver = {
248 		.name   = "vcnl3020",
249 		.of_match_table = vcnl3020_of_match,
250 	},
251 	.probe_new  = vcnl3020_probe,
252 };
253 module_i2c_driver(vcnl3020_driver);
254 
255 MODULE_AUTHOR("Ivan Mikhaylov <i.mikhaylov@yadro.com>");
256 MODULE_DESCRIPTION("Vishay VCNL3020 proximity sensor driver");
257 MODULE_LICENSE("GPL");
258