1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * STMicroelectronics uvis25 sensor driver
4 *
5 * Copyright 2017 STMicroelectronics Inc.
6 *
7 * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/iio/sysfs.h>
14 #include <linux/delay.h>
15 #include <linux/pm.h>
16 #include <linux/interrupt.h>
17 #include <linux/irqreturn.h>
18 #include <linux/iio/trigger.h>
19 #include <linux/iio/trigger_consumer.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/buffer.h>
22 #include <linux/regmap.h>
23
24 #include "st_uvis25.h"
25
26 #define ST_UVIS25_REG_WHOAMI_ADDR 0x0f
27 #define ST_UVIS25_REG_WHOAMI_VAL 0xca
28 #define ST_UVIS25_REG_CTRL1_ADDR 0x20
29 #define ST_UVIS25_REG_ODR_MASK BIT(0)
30 #define ST_UVIS25_REG_BDU_MASK BIT(1)
31 #define ST_UVIS25_REG_CTRL2_ADDR 0x21
32 #define ST_UVIS25_REG_BOOT_MASK BIT(7)
33 #define ST_UVIS25_REG_CTRL3_ADDR 0x22
34 #define ST_UVIS25_REG_HL_MASK BIT(7)
35 #define ST_UVIS25_REG_STATUS_ADDR 0x27
36 #define ST_UVIS25_REG_UV_DA_MASK BIT(0)
37 #define ST_UVIS25_REG_OUT_ADDR 0x28
38
39 static const struct iio_chan_spec st_uvis25_channels[] = {
40 {
41 .type = IIO_UVINDEX,
42 .address = ST_UVIS25_REG_OUT_ADDR,
43 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
44 .scan_index = 0,
45 .scan_type = {
46 .sign = 'u',
47 .realbits = 8,
48 .storagebits = 8,
49 },
50 },
51 IIO_CHAN_SOFT_TIMESTAMP(1),
52 };
53
st_uvis25_check_whoami(struct st_uvis25_hw * hw)54 static int st_uvis25_check_whoami(struct st_uvis25_hw *hw)
55 {
56 int err, data;
57
58 err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data);
59 if (err < 0) {
60 dev_err(regmap_get_device(hw->regmap),
61 "failed to read whoami register\n");
62 return err;
63 }
64
65 if (data != ST_UVIS25_REG_WHOAMI_VAL) {
66 dev_err(regmap_get_device(hw->regmap),
67 "wrong whoami {%02x vs %02x}\n",
68 data, ST_UVIS25_REG_WHOAMI_VAL);
69 return -ENODEV;
70 }
71
72 return 0;
73 }
74
st_uvis25_set_enable(struct st_uvis25_hw * hw,bool enable)75 static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable)
76 {
77 int err;
78
79 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
80 ST_UVIS25_REG_ODR_MASK, enable);
81 if (err < 0)
82 return err;
83
84 hw->enabled = enable;
85
86 return 0;
87 }
88
st_uvis25_read_oneshot(struct st_uvis25_hw * hw,u8 addr,int * val)89 static int st_uvis25_read_oneshot(struct st_uvis25_hw *hw, u8 addr, int *val)
90 {
91 int err;
92
93 err = st_uvis25_set_enable(hw, true);
94 if (err < 0)
95 return err;
96
97 msleep(1500);
98
99 /*
100 * in order to avoid possible race conditions with interrupt
101 * generation, disable the sensor first and then poll output
102 * register. That sequence guarantees the interrupt will be reset
103 * when irq line is unmasked
104 */
105 err = st_uvis25_set_enable(hw, false);
106 if (err < 0)
107 return err;
108
109 err = regmap_read(hw->regmap, addr, val);
110
111 return err < 0 ? err : IIO_VAL_INT;
112 }
113
st_uvis25_read_raw(struct iio_dev * iio_dev,struct iio_chan_spec const * ch,int * val,int * val2,long mask)114 static int st_uvis25_read_raw(struct iio_dev *iio_dev,
115 struct iio_chan_spec const *ch,
116 int *val, int *val2, long mask)
117 {
118 int ret;
119
120 ret = iio_device_claim_direct_mode(iio_dev);
121 if (ret)
122 return ret;
123
124 switch (mask) {
125 case IIO_CHAN_INFO_PROCESSED: {
126 struct st_uvis25_hw *hw = iio_priv(iio_dev);
127
128 /*
129 * mask irq line during oneshot read since the sensor
130 * does not export the capability to disable data-ready line
131 * in the register map and it is enabled by default.
132 * If the line is unmasked during read_raw() it will be set
133 * active and never reset since the trigger is disabled
134 */
135 if (hw->irq > 0)
136 disable_irq(hw->irq);
137 ret = st_uvis25_read_oneshot(hw, ch->address, val);
138 if (hw->irq > 0)
139 enable_irq(hw->irq);
140 break;
141 }
142 default:
143 ret = -EINVAL;
144 break;
145 }
146
147 iio_device_release_direct_mode(iio_dev);
148
149 return ret;
150 }
151
st_uvis25_trigger_handler_thread(int irq,void * private)152 static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private)
153 {
154 struct st_uvis25_hw *hw = private;
155 int err, status;
156
157 err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status);
158 if (err < 0)
159 return IRQ_HANDLED;
160
161 if (!(status & ST_UVIS25_REG_UV_DA_MASK))
162 return IRQ_NONE;
163
164 iio_trigger_poll_nested(hw->trig);
165
166 return IRQ_HANDLED;
167 }
168
st_uvis25_allocate_trigger(struct iio_dev * iio_dev)169 static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev)
170 {
171 struct st_uvis25_hw *hw = iio_priv(iio_dev);
172 struct device *dev = regmap_get_device(hw->regmap);
173 bool irq_active_low = false;
174 unsigned long irq_type;
175 int err;
176
177 irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
178
179 switch (irq_type) {
180 case IRQF_TRIGGER_HIGH:
181 case IRQF_TRIGGER_RISING:
182 break;
183 case IRQF_TRIGGER_LOW:
184 case IRQF_TRIGGER_FALLING:
185 irq_active_low = true;
186 break;
187 default:
188 dev_info(dev, "mode %lx unsupported\n", irq_type);
189 return -EINVAL;
190 }
191
192 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
193 ST_UVIS25_REG_HL_MASK, irq_active_low);
194 if (err < 0)
195 return err;
196
197 err = devm_request_threaded_irq(dev, hw->irq, NULL,
198 st_uvis25_trigger_handler_thread,
199 irq_type | IRQF_ONESHOT,
200 iio_dev->name, hw);
201 if (err) {
202 dev_err(dev, "failed to request trigger irq %d\n",
203 hw->irq);
204 return err;
205 }
206
207 hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
208 iio_dev->name);
209 if (!hw->trig)
210 return -ENOMEM;
211
212 iio_trigger_set_drvdata(hw->trig, iio_dev);
213
214 return devm_iio_trigger_register(dev, hw->trig);
215 }
216
st_uvis25_buffer_preenable(struct iio_dev * iio_dev)217 static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
218 {
219 return st_uvis25_set_enable(iio_priv(iio_dev), true);
220 }
221
st_uvis25_buffer_postdisable(struct iio_dev * iio_dev)222 static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
223 {
224 return st_uvis25_set_enable(iio_priv(iio_dev), false);
225 }
226
227 static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
228 .preenable = st_uvis25_buffer_preenable,
229 .postdisable = st_uvis25_buffer_postdisable,
230 };
231
st_uvis25_buffer_handler_thread(int irq,void * p)232 static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
233 {
234 struct iio_poll_func *pf = p;
235 struct iio_dev *iio_dev = pf->indio_dev;
236 struct st_uvis25_hw *hw = iio_priv(iio_dev);
237 unsigned int val;
238 int err;
239
240 err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val);
241 if (err < 0)
242 goto out;
243
244 hw->scan.chan = val;
245
246 iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
247 iio_get_time_ns(iio_dev));
248
249 out:
250 iio_trigger_notify_done(hw->trig);
251
252 return IRQ_HANDLED;
253 }
254
st_uvis25_allocate_buffer(struct iio_dev * iio_dev)255 static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
256 {
257 struct st_uvis25_hw *hw = iio_priv(iio_dev);
258
259 return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
260 iio_dev, NULL,
261 st_uvis25_buffer_handler_thread,
262 &st_uvis25_buffer_ops);
263 }
264
265 static const struct iio_info st_uvis25_info = {
266 .read_raw = st_uvis25_read_raw,
267 };
268
st_uvis25_init_sensor(struct st_uvis25_hw * hw)269 static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
270 {
271 int err;
272
273 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
274 ST_UVIS25_REG_BOOT_MASK, 1);
275 if (err < 0)
276 return err;
277
278 msleep(2000);
279
280 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
281 ST_UVIS25_REG_BDU_MASK, 1);
282 }
283
st_uvis25_probe(struct device * dev,int irq,struct regmap * regmap)284 int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap)
285 {
286 struct st_uvis25_hw *hw;
287 struct iio_dev *iio_dev;
288 int err;
289
290 iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
291 if (!iio_dev)
292 return -ENOMEM;
293
294 dev_set_drvdata(dev, (void *)iio_dev);
295
296 hw = iio_priv(iio_dev);
297 hw->irq = irq;
298 hw->regmap = regmap;
299
300 err = st_uvis25_check_whoami(hw);
301 if (err < 0)
302 return err;
303
304 iio_dev->modes = INDIO_DIRECT_MODE;
305 iio_dev->channels = st_uvis25_channels;
306 iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
307 iio_dev->name = ST_UVIS25_DEV_NAME;
308 iio_dev->info = &st_uvis25_info;
309
310 err = st_uvis25_init_sensor(hw);
311 if (err < 0)
312 return err;
313
314 if (hw->irq > 0) {
315 err = st_uvis25_allocate_buffer(iio_dev);
316 if (err < 0)
317 return err;
318
319 err = st_uvis25_allocate_trigger(iio_dev);
320 if (err)
321 return err;
322 }
323
324 return devm_iio_device_register(dev, iio_dev);
325 }
326 EXPORT_SYMBOL_NS(st_uvis25_probe, IIO_UVIS25);
327
st_uvis25_suspend(struct device * dev)328 static int st_uvis25_suspend(struct device *dev)
329 {
330 struct iio_dev *iio_dev = dev_get_drvdata(dev);
331 struct st_uvis25_hw *hw = iio_priv(iio_dev);
332
333 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
334 ST_UVIS25_REG_ODR_MASK, 0);
335 }
336
st_uvis25_resume(struct device * dev)337 static int st_uvis25_resume(struct device *dev)
338 {
339 struct iio_dev *iio_dev = dev_get_drvdata(dev);
340 struct st_uvis25_hw *hw = iio_priv(iio_dev);
341
342 if (hw->enabled)
343 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
344 ST_UVIS25_REG_ODR_MASK, 1);
345
346 return 0;
347 }
348
349 EXPORT_NS_SIMPLE_DEV_PM_OPS(st_uvis25_pm_ops, st_uvis25_suspend, st_uvis25_resume, IIO_UVIS25);
350
351 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
352 MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
353 MODULE_LICENSE("GPL v2");
354