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 */
44 struct 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
cm3605_prox_irq(int irq,void * d)54 static 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
cm3605_get_lux(struct cm3605 * cm3605)73 static 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
cm3605_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)105 static 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
129 static const struct iio_info cm3605_info = {
130 .read_raw = cm3605_read_raw,
131 };
132
133 static 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
141 static 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
cm3605_probe(struct platform_device * pdev)154 static 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 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 = of_property_read_u32(np, "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 return dev_err_probe(dev, irq, "failed to get irq\n");
231
232 ret = devm_request_threaded_irq(dev, irq, cm3605_prox_irq,
233 NULL, 0, "cm3605", indio_dev);
234 if (ret) {
235 dev_err(dev, "unable to request IRQ\n");
236 goto out_disable_aset;
237 }
238
239 /* Just name the trigger the same as the driver */
240 led_trigger_register_simple("cm3605", &cm3605->led);
241 led_trigger_event(cm3605->led, LED_FULL);
242
243 indio_dev->info = &cm3605_info;
244 indio_dev->name = "cm3605";
245 indio_dev->channels = cm3605_channels;
246 indio_dev->num_channels = ARRAY_SIZE(cm3605_channels);
247 indio_dev->modes = INDIO_DIRECT_MODE;
248
249 ret = iio_device_register(indio_dev);
250 if (ret)
251 goto out_remove_trigger;
252 dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n",
253 cm3605->als_max);
254
255 return 0;
256
257 out_remove_trigger:
258 led_trigger_event(cm3605->led, LED_OFF);
259 led_trigger_unregister_simple(cm3605->led);
260 out_disable_aset:
261 gpiod_set_value_cansleep(cm3605->aset, 0);
262 out_disable_vdd:
263 regulator_disable(cm3605->vdd);
264 return ret;
265 }
266
cm3605_remove(struct platform_device * pdev)267 static int cm3605_remove(struct platform_device *pdev)
268 {
269 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
270 struct cm3605 *cm3605 = iio_priv(indio_dev);
271
272 led_trigger_event(cm3605->led, LED_OFF);
273 led_trigger_unregister_simple(cm3605->led);
274 gpiod_set_value_cansleep(cm3605->aset, 0);
275 iio_device_unregister(indio_dev);
276 regulator_disable(cm3605->vdd);
277
278 return 0;
279 }
280
cm3605_pm_suspend(struct device * dev)281 static int __maybe_unused 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
cm3605_pm_resume(struct device * dev)292 static int __maybe_unused 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 }
305
306 static const struct dev_pm_ops cm3605_dev_pm_ops = {
307 SET_SYSTEM_SLEEP_PM_OPS(cm3605_pm_suspend,
308 cm3605_pm_resume)
309 };
310
311 static const struct of_device_id cm3605_of_match[] = {
312 {.compatible = "capella,cm3605"},
313 { },
314 };
315 MODULE_DEVICE_TABLE(of, cm3605_of_match);
316
317 static struct platform_driver cm3605_driver = {
318 .driver = {
319 .name = "cm3605",
320 .of_match_table = cm3605_of_match,
321 .pm = &cm3605_dev_pm_ops,
322 },
323 .probe = cm3605_probe,
324 .remove = cm3605_remove,
325 };
326 module_platform_driver(cm3605_driver);
327
328 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
329 MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver");
330 MODULE_LICENSE("GPL");
331