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 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 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 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 } 113 114 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 if (!iio_device_claim_direct(iio_dev)) 121 return -EBUSY; 122 123 switch (mask) { 124 case IIO_CHAN_INFO_PROCESSED: { 125 struct st_uvis25_hw *hw = iio_priv(iio_dev); 126 127 /* 128 * mask irq line during oneshot read since the sensor 129 * does not export the capability to disable data-ready line 130 * in the register map and it is enabled by default. 131 * If the line is unmasked during read_raw() it will be set 132 * active and never reset since the trigger is disabled 133 */ 134 if (hw->irq > 0) 135 disable_irq(hw->irq); 136 ret = st_uvis25_read_oneshot(hw, ch->address, val); 137 if (hw->irq > 0) 138 enable_irq(hw->irq); 139 break; 140 } 141 default: 142 ret = -EINVAL; 143 break; 144 } 145 146 iio_device_release_direct(iio_dev); 147 148 return ret; 149 } 150 151 static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private) 152 { 153 struct st_uvis25_hw *hw = private; 154 int err, status; 155 156 err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status); 157 if (err < 0) 158 return IRQ_HANDLED; 159 160 if (!(status & ST_UVIS25_REG_UV_DA_MASK)) 161 return IRQ_NONE; 162 163 iio_trigger_poll_nested(hw->trig); 164 165 return IRQ_HANDLED; 166 } 167 168 static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev) 169 { 170 struct st_uvis25_hw *hw = iio_priv(iio_dev); 171 struct device *dev = regmap_get_device(hw->regmap); 172 bool irq_active_low = false; 173 unsigned long irq_type; 174 int err; 175 176 irq_type = irq_get_trigger_type(hw->irq); 177 switch (irq_type) { 178 case IRQF_TRIGGER_HIGH: 179 case IRQF_TRIGGER_RISING: 180 break; 181 case IRQF_TRIGGER_LOW: 182 case IRQF_TRIGGER_FALLING: 183 irq_active_low = true; 184 break; 185 default: 186 dev_info(dev, "mode %lx unsupported\n", irq_type); 187 return -EINVAL; 188 } 189 190 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR, 191 ST_UVIS25_REG_HL_MASK, irq_active_low); 192 if (err < 0) 193 return err; 194 195 err = devm_request_threaded_irq(dev, hw->irq, NULL, 196 st_uvis25_trigger_handler_thread, 197 irq_type | IRQF_ONESHOT, 198 iio_dev->name, hw); 199 if (err) { 200 dev_err(dev, "failed to request trigger irq %d\n", 201 hw->irq); 202 return err; 203 } 204 205 hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger", 206 iio_dev->name); 207 if (!hw->trig) 208 return -ENOMEM; 209 210 iio_trigger_set_drvdata(hw->trig, iio_dev); 211 212 return devm_iio_trigger_register(dev, hw->trig); 213 } 214 215 static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev) 216 { 217 return st_uvis25_set_enable(iio_priv(iio_dev), true); 218 } 219 220 static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev) 221 { 222 return st_uvis25_set_enable(iio_priv(iio_dev), false); 223 } 224 225 static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = { 226 .preenable = st_uvis25_buffer_preenable, 227 .postdisable = st_uvis25_buffer_postdisable, 228 }; 229 230 static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p) 231 { 232 struct iio_poll_func *pf = p; 233 struct iio_dev *iio_dev = pf->indio_dev; 234 struct st_uvis25_hw *hw = iio_priv(iio_dev); 235 unsigned int val; 236 int err; 237 238 err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val); 239 if (err < 0) 240 goto out; 241 242 hw->scan.chan = val; 243 244 iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, 245 iio_get_time_ns(iio_dev)); 246 247 out: 248 iio_trigger_notify_done(hw->trig); 249 250 return IRQ_HANDLED; 251 } 252 253 static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev) 254 { 255 struct st_uvis25_hw *hw = iio_priv(iio_dev); 256 257 return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap), 258 iio_dev, NULL, 259 st_uvis25_buffer_handler_thread, 260 &st_uvis25_buffer_ops); 261 } 262 263 static const struct iio_info st_uvis25_info = { 264 .read_raw = st_uvis25_read_raw, 265 }; 266 267 static int st_uvis25_init_sensor(struct st_uvis25_hw *hw) 268 { 269 int err; 270 271 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR, 272 ST_UVIS25_REG_BOOT_MASK, 1); 273 if (err < 0) 274 return err; 275 276 msleep(2000); 277 278 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 279 ST_UVIS25_REG_BDU_MASK, 1); 280 } 281 282 int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap) 283 { 284 struct st_uvis25_hw *hw; 285 struct iio_dev *iio_dev; 286 int err; 287 288 iio_dev = devm_iio_device_alloc(dev, sizeof(*hw)); 289 if (!iio_dev) 290 return -ENOMEM; 291 292 dev_set_drvdata(dev, iio_dev); 293 294 hw = iio_priv(iio_dev); 295 hw->irq = irq; 296 hw->regmap = regmap; 297 298 err = st_uvis25_check_whoami(hw); 299 if (err < 0) 300 return err; 301 302 iio_dev->modes = INDIO_DIRECT_MODE; 303 iio_dev->channels = st_uvis25_channels; 304 iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels); 305 iio_dev->name = ST_UVIS25_DEV_NAME; 306 iio_dev->info = &st_uvis25_info; 307 308 err = st_uvis25_init_sensor(hw); 309 if (err < 0) 310 return err; 311 312 if (hw->irq > 0) { 313 err = st_uvis25_allocate_buffer(iio_dev); 314 if (err < 0) 315 return err; 316 317 err = st_uvis25_allocate_trigger(iio_dev); 318 if (err) 319 return err; 320 } 321 322 return devm_iio_device_register(dev, iio_dev); 323 } 324 EXPORT_SYMBOL_NS(st_uvis25_probe, "IIO_UVIS25"); 325 326 static int st_uvis25_suspend(struct device *dev) 327 { 328 struct iio_dev *iio_dev = dev_get_drvdata(dev); 329 struct st_uvis25_hw *hw = iio_priv(iio_dev); 330 331 return regmap_clear_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 332 ST_UVIS25_REG_ODR_MASK); 333 } 334 335 static int st_uvis25_resume(struct device *dev) 336 { 337 struct iio_dev *iio_dev = dev_get_drvdata(dev); 338 struct st_uvis25_hw *hw = iio_priv(iio_dev); 339 340 if (hw->enabled) 341 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 342 ST_UVIS25_REG_ODR_MASK, 1); 343 344 return 0; 345 } 346 347 EXPORT_NS_SIMPLE_DEV_PM_OPS(st_uvis25_pm_ops, st_uvis25_suspend, st_uvis25_resume, IIO_UVIS25); 348 349 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>"); 350 MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver"); 351 MODULE_LICENSE("GPL v2"); 352