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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CM3605 Ambient Light and Proximity Sensor
4 *
5 * Copyright (C) 2016 Linaro Ltd.
6 * Author: Linus Walleij <linus.walleij@linaro.org>
7 *
8 * This hardware was found in the very first Nexus One handset from Google/HTC
9 * and an early endavour into mobile light and proximity sensors.
10 */
11
12#include <linux/module.h>
13#include <linux/mod_devicetable.h>
14#include <linux/iio/iio.h>
15#include <linux/iio/sysfs.h>
16#include <linux/iio/events.h>
17#include <linux/iio/consumer.h> /* To get our ADC channel */
18#include <linux/iio/types.h> /* To deal with our ADC channel */
19#include <linux/init.h>
20#include <linux/leds.h>
21#include <linux/platform_device.h>
22#include <linux/property.h>
23#include <linux/regulator/consumer.h>
24#include <linux/gpio/consumer.h>
25#include <linux/interrupt.h>
26#include <linux/math64.h>
27#include <linux/pm.h>
28
29#define CM3605_PROX_CHANNEL 0
30#define CM3605_ALS_CHANNEL 1
31#define CM3605_AOUT_TYP_MAX_MV 1550
32/* It should not go above 1.650V according to the data sheet */
33#define CM3605_AOUT_MAX_MV 1650
34
35/**
36 * struct cm3605 - CM3605 state
37 * @dev: pointer to parent device
38 * @vdd: regulator controlling VDD
39 * @aset: sleep enable GPIO, high = sleep
40 * @aout: IIO ADC channel to convert the AOUT signal
41 * @als_max: maximum LUX detection (depends on RSET)
42 * @dir: proximity direction: start as FALLING
43 * @led: trigger for the infrared LED used by the proximity sensor
44 */
45struct cm3605 {
46 struct device *dev;
47 struct regulator *vdd;
48 struct gpio_desc *aset;
49 struct iio_channel *aout;
50 s32 als_max;
51 enum iio_event_direction dir;
52 struct led_trigger *led;
53};
54
55static irqreturn_t cm3605_prox_irq(int irq, void *d)
56{
57 struct iio_dev *indio_dev = d;
58 struct cm3605 *cm3605 = iio_priv(indio_dev);
59 u64 ev;
60
61 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL,
62 IIO_EV_TYPE_THRESH, cm3605->dir);
63 iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
64
65 /* Invert the edge for each event */
66 if (cm3605->dir == IIO_EV_DIR_RISING)
67 cm3605->dir = IIO_EV_DIR_FALLING;
68 else
69 cm3605->dir = IIO_EV_DIR_RISING;
70
71 return IRQ_HANDLED;
72}
73
74static int cm3605_get_lux(struct cm3605 *cm3605)
75{
76 int ret, res;
77 s64 lux;
78
79 ret = iio_read_channel_processed(cm3605->aout, &res);
80 if (ret < 0)
81 return ret;
82
83 dev_dbg(cm3605->dev, "read %d mV from ADC\n", res);
84
85 /*
86 * AOUT has an offset of ~30mV then linear at dark
87 * then goes from 2.54 up to 650 LUX yielding 1.55V
88 * (1550 mV) so scale the returned value to this interval
89 * using simple linear interpolation.
90 */
91 if (res < 30)
92 return 0;
93 if (res > CM3605_AOUT_MAX_MV)
94 dev_err(cm3605->dev, "device out of range\n");
95
96 /* Remove bias */
97 lux = res - 30;
98
99 /* Linear interpolation between 0 and ALS typ max */
100 lux *= cm3605->als_max;
101 lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV);
102
103 return lux;
104}
105
106static int cm3605_read_raw(struct iio_dev *indio_dev,
107 struct iio_chan_spec const *chan,
108 int *val, int *val2, long mask)
109{
110 struct cm3605 *cm3605 = iio_priv(indio_dev);
111 int ret;
112
113 switch (mask) {
114 case IIO_CHAN_INFO_RAW:
115 switch (chan->type) {
116 case IIO_LIGHT:
117 ret = cm3605_get_lux(cm3605);
118 if (ret < 0)
119 return ret;
120 *val = ret;
121 return IIO_VAL_INT;
122 default:
123 return -EINVAL;
124 }
125 default:
126 return -EINVAL;
127 }
128}
129
130static const struct iio_info cm3605_info = {
131 .read_raw = cm3605_read_raw,
132};
133
134static const struct iio_event_spec cm3605_events[] = {
135 {
136 .type = IIO_EV_TYPE_THRESH,
137 .dir = IIO_EV_DIR_EITHER,
138 .mask_separate = BIT(IIO_EV_INFO_ENABLE),
139 },
140};
141
142static const struct iio_chan_spec cm3605_channels[] = {
143 {
144 .type = IIO_PROXIMITY,
145 .event_spec = cm3605_events,
146 .num_event_specs = ARRAY_SIZE(cm3605_events),
147 },
148 {
149 .type = IIO_LIGHT,
150 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
151 .channel = CM3605_ALS_CHANNEL,
152 },
153};
154
155static int cm3605_probe(struct platform_device *pdev)
156{
157 struct cm3605 *cm3605;
158 struct iio_dev *indio_dev;
159 struct device *dev = &pdev->dev;
160 enum iio_chan_type ch_type;
161 u32 rset;
162 int irq;
163 int ret;
164
165 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605));
166 if (!indio_dev)
167 return -ENOMEM;
168 platform_set_drvdata(pdev, indio_dev);
169
170 cm3605 = iio_priv(indio_dev);
171 cm3605->dev = dev;
172 cm3605->dir = IIO_EV_DIR_FALLING;
173
174 ret = device_property_read_u32(dev, "capella,aset-resistance-ohms", &rset);
175 if (ret) {
176 dev_info(dev, "no RSET specified, assuming 100K\n");
177 rset = 100000;
178 }
179 switch (rset) {
180 case 50000:
181 cm3605->als_max = 650;
182 break;
183 case 100000:
184 cm3605->als_max = 300;
185 break;
186 case 300000:
187 cm3605->als_max = 100;
188 break;
189 case 600000:
190 cm3605->als_max = 50;
191 break;
192 default:
193 dev_info(dev, "non-standard resistance\n");
194 return -EINVAL;
195 }
196
197 cm3605->aout = devm_iio_channel_get(dev, "aout");
198 if (IS_ERR(cm3605->aout)) {
199 ret = PTR_ERR(cm3605->aout);
200 ret = (ret == -ENODEV) ? -EPROBE_DEFER : ret;
201 return dev_err_probe(dev, ret, "failed to get AOUT ADC channel\n");
202 }
203 ret = iio_get_channel_type(cm3605->aout, &ch_type);
204 if (ret < 0)
205 return ret;
206 if (ch_type != IIO_VOLTAGE) {
207 dev_err(dev, "wrong type of IIO channel specified for AOUT\n");
208 return -EINVAL;
209 }
210
211 cm3605->vdd = devm_regulator_get(dev, "vdd");
212 if (IS_ERR(cm3605->vdd))
213 return dev_err_probe(dev, PTR_ERR(cm3605->vdd),
214 "failed to get VDD regulator\n");
215
216 ret = regulator_enable(cm3605->vdd);
217 if (ret) {
218 dev_err(dev, "failed to enable VDD regulator\n");
219 return ret;
220 }
221
222 cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH);
223 if (IS_ERR(cm3605->aset)) {
224 ret = dev_err_probe(dev, PTR_ERR(cm3605->aset), "no ASET GPIO\n");
225 goto out_disable_vdd;
226 }
227
228 irq = platform_get_irq(pdev, 0);
229 if (irq < 0) {
230 ret = irq;
231 goto out_disable_aset;
232 }
233
234 ret = devm_request_threaded_irq(dev, irq, cm3605_prox_irq,
235 NULL, 0, "cm3605", indio_dev);
236 if (ret) {
237 dev_err(dev, "unable to request IRQ\n");
238 goto out_disable_aset;
239 }
240
241 /* Just name the trigger the same as the driver */
242 led_trigger_register_simple("cm3605", &cm3605->led);
243 led_trigger_event(cm3605->led, LED_FULL);
244
245 indio_dev->info = &cm3605_info;
246 indio_dev->name = "cm3605";
247 indio_dev->channels = cm3605_channels;
248 indio_dev->num_channels = ARRAY_SIZE(cm3605_channels);
249 indio_dev->modes = INDIO_DIRECT_MODE;
250
251 ret = iio_device_register(indio_dev);
252 if (ret)
253 goto out_remove_trigger;
254 dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n",
255 cm3605->als_max);
256
257 return 0;
258
259out_remove_trigger:
260 led_trigger_event(cm3605->led, LED_OFF);
261 led_trigger_unregister_simple(cm3605->led);
262out_disable_aset:
263 gpiod_set_value_cansleep(cm3605->aset, 0);
264out_disable_vdd:
265 regulator_disable(cm3605->vdd);
266 return ret;
267}
268
269static void cm3605_remove(struct platform_device *pdev)
270{
271 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
272 struct cm3605 *cm3605 = iio_priv(indio_dev);
273
274 led_trigger_event(cm3605->led, LED_OFF);
275 led_trigger_unregister_simple(cm3605->led);
276 gpiod_set_value_cansleep(cm3605->aset, 0);
277 iio_device_unregister(indio_dev);
278 regulator_disable(cm3605->vdd);
279}
280
281static int cm3605_pm_suspend(struct device *dev)
282{
283 struct iio_dev *indio_dev = dev_get_drvdata(dev);
284 struct cm3605 *cm3605 = iio_priv(indio_dev);
285
286 led_trigger_event(cm3605->led, LED_OFF);
287 regulator_disable(cm3605->vdd);
288
289 return 0;
290}
291
292static int cm3605_pm_resume(struct device *dev)
293{
294 struct iio_dev *indio_dev = dev_get_drvdata(dev);
295 struct cm3605 *cm3605 = iio_priv(indio_dev);
296 int ret;
297
298 ret = regulator_enable(cm3605->vdd);
299 if (ret)
300 dev_err(dev, "failed to enable regulator in resume path\n");
301 led_trigger_event(cm3605->led, LED_FULL);
302
303 return 0;
304}
305static DEFINE_SIMPLE_DEV_PM_OPS(cm3605_dev_pm_ops, cm3605_pm_suspend,
306 cm3605_pm_resume);
307
308static const struct of_device_id cm3605_of_match[] = {
309 {.compatible = "capella,cm3605"},
310 { },
311};
312MODULE_DEVICE_TABLE(of, cm3605_of_match);
313
314static struct platform_driver cm3605_driver = {
315 .driver = {
316 .name = "cm3605",
317 .of_match_table = cm3605_of_match,
318 .pm = pm_sleep_ptr(&cm3605_dev_pm_ops),
319 },
320 .probe = cm3605_probe,
321 .remove = cm3605_remove,
322};
323module_platform_driver(cm3605_driver);
324
325MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
326MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver");
327MODULE_LICENSE("GPL");