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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/iio/iio.h>
14#include <linux/iio/sysfs.h>
15#include <linux/iio/events.h>
16#include <linux/iio/consumer.h> /* To get our ADC channel */
17#include <linux/iio/types.h> /* To deal with our ADC channel */
18#include <linux/init.h>
19#include <linux/leds.h>
20#include <linux/platform_device.h>
21#include <linux/of.h>
22#include <linux/regulator/consumer.h>
23#include <linux/gpio/consumer.h>
24#include <linux/interrupt.h>
25#include <linux/math64.h>
26#include <linux/pm.h>
27
28#define CM3605_PROX_CHANNEL 0
29#define CM3605_ALS_CHANNEL 1
30#define CM3605_AOUT_TYP_MAX_MV 1550
31/* It should not go above 1.650V according to the data sheet */
32#define CM3605_AOUT_MAX_MV 1650
33
34/**
35 * struct cm3605 - CM3605 state
36 * @dev: pointer to parent device
37 * @vdd: regulator controlling VDD
38 * @aset: sleep enable GPIO, high = sleep
39 * @aout: IIO ADC channel to convert the AOUT signal
40 * @als_max: maximum LUX detection (depends on RSET)
41 * @dir: proximity direction: start as FALLING
42 * @led: trigger for the infrared LED used by the proximity sensor
43 */
44struct cm3605 {
45 struct device *dev;
46 struct regulator *vdd;
47 struct gpio_desc *aset;
48 struct iio_channel *aout;
49 s32 als_max;
50 enum iio_event_direction dir;
51 struct led_trigger *led;
52};
53
54static irqreturn_t cm3605_prox_irq(int irq, void *d)
55{
56 struct iio_dev *indio_dev = d;
57 struct cm3605 *cm3605 = iio_priv(indio_dev);
58 u64 ev;
59
60 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL,
61 IIO_EV_TYPE_THRESH, cm3605->dir);
62 iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
63
64 /* Invert the edge for each event */
65 if (cm3605->dir == IIO_EV_DIR_RISING)
66 cm3605->dir = IIO_EV_DIR_FALLING;
67 else
68 cm3605->dir = IIO_EV_DIR_RISING;
69
70 return IRQ_HANDLED;
71}
72
73static int cm3605_get_lux(struct cm3605 *cm3605)
74{
75 int ret, res;
76 s64 lux;
77
78 ret = iio_read_channel_processed(cm3605->aout, &res);
79 if (ret < 0)
80 return ret;
81
82 dev_dbg(cm3605->dev, "read %d mV from ADC\n", res);
83
84 /*
85 * AOUT has an offset of ~30mV then linear at dark
86 * then goes from 2.54 up to 650 LUX yielding 1.55V
87 * (1550 mV) so scale the returned value to this interval
88 * using simple linear interpolation.
89 */
90 if (res < 30)
91 return 0;
92 if (res > CM3605_AOUT_MAX_MV)
93 dev_err(cm3605->dev, "device out of range\n");
94
95 /* Remove bias */
96 lux = res - 30;
97
98 /* Linear interpolation between 0 and ALS typ max */
99 lux *= cm3605->als_max;
100 lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV);
101
102 return lux;
103}
104
105static int cm3605_read_raw(struct iio_dev *indio_dev,
106 struct iio_chan_spec const *chan,
107 int *val, int *val2, long mask)
108{
109 struct cm3605 *cm3605 = iio_priv(indio_dev);
110 int ret;
111
112 switch (mask) {
113 case IIO_CHAN_INFO_RAW:
114 switch (chan->type) {
115 case IIO_LIGHT:
116 ret = cm3605_get_lux(cm3605);
117 if (ret < 0)
118 return ret;
119 *val = ret;
120 return IIO_VAL_INT;
121 default:
122 return -EINVAL;
123 }
124 default:
125 return -EINVAL;
126 }
127}
128
129static const struct iio_info cm3605_info = {
130 .read_raw = cm3605_read_raw,
131};
132
133static const struct iio_event_spec cm3605_events[] = {
134 {
135 .type = IIO_EV_TYPE_THRESH,
136 .dir = IIO_EV_DIR_EITHER,
137 .mask_separate = BIT(IIO_EV_INFO_ENABLE),
138 },
139};
140
141static const struct iio_chan_spec cm3605_channels[] = {
142 {
143 .type = IIO_PROXIMITY,
144 .event_spec = cm3605_events,
145 .num_event_specs = ARRAY_SIZE(cm3605_events),
146 },
147 {
148 .type = IIO_LIGHT,
149 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
150 .channel = CM3605_ALS_CHANNEL,
151 },
152};
153
154static int cm3605_probe(struct platform_device *pdev)
155{
156 struct cm3605 *cm3605;
157 struct iio_dev *indio_dev;
158 struct device *dev = &pdev->dev;
159 struct device_node *np = dev->of_node;
160 enum iio_chan_type ch_type;
161 u32 rset;
162 int ret;
163
164 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605));
165 if (!indio_dev)
166 return -ENOMEM;
167 platform_set_drvdata(pdev, indio_dev);
168
169 cm3605 = iio_priv(indio_dev);
170 cm3605->dev = dev;
171 cm3605->dir = IIO_EV_DIR_FALLING;
172
173 ret = of_property_read_u32(np, "capella,aset-resistance-ohms", &rset);
174 if (ret) {
175 dev_info(dev, "no RSET specified, assuming 100K\n");
176 rset = 100000;
177 }
178 switch (rset) {
179 case 50000:
180 cm3605->als_max = 650;
181 break;
182 case 100000:
183 cm3605->als_max = 300;
184 break;
185 case 300000:
186 cm3605->als_max = 100;
187 break;
188 case 600000:
189 cm3605->als_max = 50;
190 break;
191 default:
192 dev_info(dev, "non-standard resistance\n");
193 return -EINVAL;
194 }
195
196 cm3605->aout = devm_iio_channel_get(dev, "aout");
197 if (IS_ERR(cm3605->aout)) {
198 if (PTR_ERR(cm3605->aout) == -ENODEV) {
199 dev_err(dev, "no ADC, deferring...\n");
200 return -EPROBE_DEFER;
201 }
202 dev_err(dev, "failed to get AOUT ADC channel\n");
203 return PTR_ERR(cm3605->aout);
204 }
205 ret = iio_get_channel_type(cm3605->aout, &ch_type);
206 if (ret < 0)
207 return ret;
208 if (ch_type != IIO_VOLTAGE) {
209 dev_err(dev, "wrong type of IIO channel specified for AOUT\n");
210 return -EINVAL;
211 }
212
213 cm3605->vdd = devm_regulator_get(dev, "vdd");
214 if (IS_ERR(cm3605->vdd)) {
215 dev_err(dev, "failed to get VDD regulator\n");
216 return PTR_ERR(cm3605->vdd);
217 }
218 ret = regulator_enable(cm3605->vdd);
219 if (ret) {
220 dev_err(dev, "failed to enable VDD regulator\n");
221 return ret;
222 }
223
224 cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH);
225 if (IS_ERR(cm3605->aset)) {
226 dev_err(dev, "no ASET GPIO\n");
227 ret = PTR_ERR(cm3605->aset);
228 goto out_disable_vdd;
229 }
230
231 ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
232 cm3605_prox_irq, NULL, 0, "cm3605", indio_dev);
233 if (ret) {
234 dev_err(dev, "unable to request IRQ\n");
235 goto out_disable_aset;
236 }
237
238 /* Just name the trigger the same as the driver */
239 led_trigger_register_simple("cm3605", &cm3605->led);
240 led_trigger_event(cm3605->led, LED_FULL);
241
242 indio_dev->info = &cm3605_info;
243 indio_dev->name = "cm3605";
244 indio_dev->channels = cm3605_channels;
245 indio_dev->num_channels = ARRAY_SIZE(cm3605_channels);
246 indio_dev->modes = INDIO_DIRECT_MODE;
247
248 ret = iio_device_register(indio_dev);
249 if (ret)
250 goto out_remove_trigger;
251 dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n",
252 cm3605->als_max);
253
254 return 0;
255
256out_remove_trigger:
257 led_trigger_event(cm3605->led, LED_OFF);
258 led_trigger_unregister_simple(cm3605->led);
259out_disable_aset:
260 gpiod_set_value_cansleep(cm3605->aset, 0);
261out_disable_vdd:
262 regulator_disable(cm3605->vdd);
263 return ret;
264}
265
266static int cm3605_remove(struct platform_device *pdev)
267{
268 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
269 struct cm3605 *cm3605 = iio_priv(indio_dev);
270
271 led_trigger_event(cm3605->led, LED_OFF);
272 led_trigger_unregister_simple(cm3605->led);
273 gpiod_set_value_cansleep(cm3605->aset, 0);
274 iio_device_unregister(indio_dev);
275 regulator_disable(cm3605->vdd);
276
277 return 0;
278}
279
280static int __maybe_unused cm3605_pm_suspend(struct device *dev)
281{
282 struct iio_dev *indio_dev = dev_get_drvdata(dev);
283 struct cm3605 *cm3605 = iio_priv(indio_dev);
284
285 led_trigger_event(cm3605->led, LED_OFF);
286 regulator_disable(cm3605->vdd);
287
288 return 0;
289}
290
291static int __maybe_unused cm3605_pm_resume(struct device *dev)
292{
293 struct iio_dev *indio_dev = dev_get_drvdata(dev);
294 struct cm3605 *cm3605 = iio_priv(indio_dev);
295 int ret;
296
297 ret = regulator_enable(cm3605->vdd);
298 if (ret)
299 dev_err(dev, "failed to enable regulator in resume path\n");
300 led_trigger_event(cm3605->led, LED_FULL);
301
302 return 0;
303}
304
305static const struct dev_pm_ops cm3605_dev_pm_ops = {
306 SET_SYSTEM_SLEEP_PM_OPS(cm3605_pm_suspend,
307 cm3605_pm_resume)
308};
309
310static const struct of_device_id cm3605_of_match[] = {
311 {.compatible = "capella,cm3605"},
312 { },
313};
314MODULE_DEVICE_TABLE(of, cm3605_of_match);
315
316static struct platform_driver cm3605_driver = {
317 .driver = {
318 .name = "cm3605",
319 .of_match_table = cm3605_of_match,
320 .pm = &cm3605_dev_pm_ops,
321 },
322 .probe = cm3605_probe,
323 .remove = cm3605_remove,
324};
325module_platform_driver(cm3605_driver);
326
327MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
328MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver");
329MODULE_LICENSE("GPL");