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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
39static 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
54static 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
75static 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
89static 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
114static 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
152static 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
169static 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 = irq_get_trigger_type(hw->irq);
178 switch (irq_type) {
179 case IRQF_TRIGGER_HIGH:
180 case IRQF_TRIGGER_RISING:
181 break;
182 case IRQF_TRIGGER_LOW:
183 case IRQF_TRIGGER_FALLING:
184 irq_active_low = true;
185 break;
186 default:
187 dev_info(dev, "mode %lx unsupported\n", irq_type);
188 return -EINVAL;
189 }
190
191 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
192 ST_UVIS25_REG_HL_MASK, irq_active_low);
193 if (err < 0)
194 return err;
195
196 err = devm_request_threaded_irq(dev, hw->irq, NULL,
197 st_uvis25_trigger_handler_thread,
198 irq_type | IRQF_ONESHOT,
199 iio_dev->name, hw);
200 if (err) {
201 dev_err(dev, "failed to request trigger irq %d\n",
202 hw->irq);
203 return err;
204 }
205
206 hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
207 iio_dev->name);
208 if (!hw->trig)
209 return -ENOMEM;
210
211 iio_trigger_set_drvdata(hw->trig, iio_dev);
212
213 return devm_iio_trigger_register(dev, hw->trig);
214}
215
216static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
217{
218 return st_uvis25_set_enable(iio_priv(iio_dev), true);
219}
220
221static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
222{
223 return st_uvis25_set_enable(iio_priv(iio_dev), false);
224}
225
226static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
227 .preenable = st_uvis25_buffer_preenable,
228 .postdisable = st_uvis25_buffer_postdisable,
229};
230
231static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
232{
233 struct iio_poll_func *pf = p;
234 struct iio_dev *iio_dev = pf->indio_dev;
235 struct st_uvis25_hw *hw = iio_priv(iio_dev);
236 unsigned int val;
237 int err;
238
239 err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val);
240 if (err < 0)
241 goto out;
242
243 hw->scan.chan = val;
244
245 iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
246 iio_get_time_ns(iio_dev));
247
248out:
249 iio_trigger_notify_done(hw->trig);
250
251 return IRQ_HANDLED;
252}
253
254static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
255{
256 struct st_uvis25_hw *hw = iio_priv(iio_dev);
257
258 return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
259 iio_dev, NULL,
260 st_uvis25_buffer_handler_thread,
261 &st_uvis25_buffer_ops);
262}
263
264static const struct iio_info st_uvis25_info = {
265 .read_raw = st_uvis25_read_raw,
266};
267
268static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
269{
270 int err;
271
272 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
273 ST_UVIS25_REG_BOOT_MASK, 1);
274 if (err < 0)
275 return err;
276
277 msleep(2000);
278
279 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
280 ST_UVIS25_REG_BDU_MASK, 1);
281}
282
283int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap)
284{
285 struct st_uvis25_hw *hw;
286 struct iio_dev *iio_dev;
287 int err;
288
289 iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
290 if (!iio_dev)
291 return -ENOMEM;
292
293 dev_set_drvdata(dev, iio_dev);
294
295 hw = iio_priv(iio_dev);
296 hw->irq = irq;
297 hw->regmap = regmap;
298
299 err = st_uvis25_check_whoami(hw);
300 if (err < 0)
301 return err;
302
303 iio_dev->modes = INDIO_DIRECT_MODE;
304 iio_dev->channels = st_uvis25_channels;
305 iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
306 iio_dev->name = ST_UVIS25_DEV_NAME;
307 iio_dev->info = &st_uvis25_info;
308
309 err = st_uvis25_init_sensor(hw);
310 if (err < 0)
311 return err;
312
313 if (hw->irq > 0) {
314 err = st_uvis25_allocate_buffer(iio_dev);
315 if (err < 0)
316 return err;
317
318 err = st_uvis25_allocate_trigger(iio_dev);
319 if (err)
320 return err;
321 }
322
323 return devm_iio_device_register(dev, iio_dev);
324}
325EXPORT_SYMBOL_NS(st_uvis25_probe, "IIO_UVIS25");
326
327static int st_uvis25_suspend(struct device *dev)
328{
329 struct iio_dev *iio_dev = dev_get_drvdata(dev);
330 struct st_uvis25_hw *hw = iio_priv(iio_dev);
331
332 return regmap_clear_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
333 ST_UVIS25_REG_ODR_MASK);
334}
335
336static int st_uvis25_resume(struct device *dev)
337{
338 struct iio_dev *iio_dev = dev_get_drvdata(dev);
339 struct st_uvis25_hw *hw = iio_priv(iio_dev);
340
341 if (hw->enabled)
342 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
343 ST_UVIS25_REG_ODR_MASK, 1);
344
345 return 0;
346}
347
348EXPORT_NS_SIMPLE_DEV_PM_OPS(st_uvis25_pm_ops, st_uvis25_suspend, st_uvis25_resume, IIO_UVIS25);
349
350MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
351MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
352MODULE_LICENSE("GPL v2");