1 /* 2 * STMicroelectronics uvis25 sensor driver 3 * 4 * Copyright 2017 STMicroelectronics Inc. 5 * 6 * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com> 7 * 8 * Licensed under the GPL-2. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/device.h> 14 #include <linux/iio/sysfs.h> 15 #include <linux/delay.h> 16 #include <linux/pm.h> 17 #include <linux/interrupt.h> 18 #include <linux/irqreturn.h> 19 #include <linux/iio/trigger.h> 20 #include <linux/iio/trigger_consumer.h> 21 #include <linux/iio/triggered_buffer.h> 22 #include <linux/iio/buffer.h> 23 #include <linux/regmap.h> 24 25 #include "st_uvis25.h" 26 27 #define ST_UVIS25_REG_WHOAMI_ADDR 0x0f 28 #define ST_UVIS25_REG_WHOAMI_VAL 0xca 29 #define ST_UVIS25_REG_CTRL1_ADDR 0x20 30 #define ST_UVIS25_REG_ODR_MASK BIT(0) 31 #define ST_UVIS25_REG_BDU_MASK BIT(1) 32 #define ST_UVIS25_REG_CTRL2_ADDR 0x21 33 #define ST_UVIS25_REG_BOOT_MASK BIT(7) 34 #define ST_UVIS25_REG_CTRL3_ADDR 0x22 35 #define ST_UVIS25_REG_HL_MASK BIT(7) 36 #define ST_UVIS25_REG_STATUS_ADDR 0x27 37 #define ST_UVIS25_REG_UV_DA_MASK BIT(0) 38 #define ST_UVIS25_REG_OUT_ADDR 0x28 39 40 static const struct iio_chan_spec st_uvis25_channels[] = { 41 { 42 .type = IIO_UVINDEX, 43 .address = ST_UVIS25_REG_OUT_ADDR, 44 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 45 .scan_index = 0, 46 .scan_type = { 47 .sign = 'u', 48 .realbits = 8, 49 .storagebits = 8, 50 }, 51 }, 52 IIO_CHAN_SOFT_TIMESTAMP(1), 53 }; 54 55 static int st_uvis25_check_whoami(struct st_uvis25_hw *hw) 56 { 57 int err, data; 58 59 err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data); 60 if (err < 0) { 61 dev_err(regmap_get_device(hw->regmap), 62 "failed to read whoami register\n"); 63 return err; 64 } 65 66 if (data != ST_UVIS25_REG_WHOAMI_VAL) { 67 dev_err(regmap_get_device(hw->regmap), 68 "wrong whoami {%02x vs %02x}\n", 69 data, ST_UVIS25_REG_WHOAMI_VAL); 70 return -ENODEV; 71 } 72 73 return 0; 74 } 75 76 static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable) 77 { 78 int err; 79 80 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 81 ST_UVIS25_REG_ODR_MASK, enable); 82 if (err < 0) 83 return err; 84 85 hw->enabled = enable; 86 87 return 0; 88 } 89 90 static int st_uvis25_read_oneshot(struct st_uvis25_hw *hw, u8 addr, int *val) 91 { 92 int err; 93 94 err = st_uvis25_set_enable(hw, true); 95 if (err < 0) 96 return err; 97 98 msleep(1500); 99 100 /* 101 * in order to avoid possible race conditions with interrupt 102 * generation, disable the sensor first and then poll output 103 * register. That sequence guarantees the interrupt will be reset 104 * when irq line is unmasked 105 */ 106 err = st_uvis25_set_enable(hw, false); 107 if (err < 0) 108 return err; 109 110 err = regmap_read(hw->regmap, addr, val); 111 112 return err < 0 ? err : IIO_VAL_INT; 113 } 114 115 static int st_uvis25_read_raw(struct iio_dev *iio_dev, 116 struct iio_chan_spec const *ch, 117 int *val, int *val2, long mask) 118 { 119 int ret; 120 121 ret = iio_device_claim_direct_mode(iio_dev); 122 if (ret) 123 return ret; 124 125 switch (mask) { 126 case IIO_CHAN_INFO_PROCESSED: { 127 struct st_uvis25_hw *hw = iio_priv(iio_dev); 128 129 /* 130 * mask irq line during oneshot read since the sensor 131 * does not export the capability to disable data-ready line 132 * in the register map and it is enabled by default. 133 * If the line is unmasked during read_raw() it will be set 134 * active and never reset since the trigger is disabled 135 */ 136 if (hw->irq > 0) 137 disable_irq(hw->irq); 138 ret = st_uvis25_read_oneshot(hw, ch->address, val); 139 if (hw->irq > 0) 140 enable_irq(hw->irq); 141 break; 142 } 143 default: 144 ret = -EINVAL; 145 break; 146 } 147 148 iio_device_release_direct_mode(iio_dev); 149 150 return ret; 151 } 152 153 static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private) 154 { 155 struct st_uvis25_hw *hw = private; 156 int err, status; 157 158 err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status); 159 if (err < 0) 160 return IRQ_HANDLED; 161 162 if (!(status & ST_UVIS25_REG_UV_DA_MASK)) 163 return IRQ_NONE; 164 165 iio_trigger_poll_chained(hw->trig); 166 167 return IRQ_HANDLED; 168 } 169 170 static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev) 171 { 172 struct st_uvis25_hw *hw = iio_priv(iio_dev); 173 struct device *dev = regmap_get_device(hw->regmap); 174 bool irq_active_low = false; 175 unsigned long irq_type; 176 int err; 177 178 irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq)); 179 180 switch (irq_type) { 181 case IRQF_TRIGGER_HIGH: 182 case IRQF_TRIGGER_RISING: 183 break; 184 case IRQF_TRIGGER_LOW: 185 case IRQF_TRIGGER_FALLING: 186 irq_active_low = true; 187 break; 188 default: 189 dev_info(dev, "mode %lx unsupported\n", irq_type); 190 return -EINVAL; 191 } 192 193 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR, 194 ST_UVIS25_REG_HL_MASK, irq_active_low); 195 if (err < 0) 196 return err; 197 198 err = devm_request_threaded_irq(dev, hw->irq, NULL, 199 st_uvis25_trigger_handler_thread, 200 irq_type | IRQF_ONESHOT, 201 iio_dev->name, hw); 202 if (err) { 203 dev_err(dev, "failed to request trigger irq %d\n", 204 hw->irq); 205 return err; 206 } 207 208 hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger", 209 iio_dev->name); 210 if (!hw->trig) 211 return -ENOMEM; 212 213 iio_trigger_set_drvdata(hw->trig, iio_dev); 214 hw->trig->dev.parent = dev; 215 216 return devm_iio_trigger_register(dev, hw->trig); 217 } 218 219 static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev) 220 { 221 return st_uvis25_set_enable(iio_priv(iio_dev), true); 222 } 223 224 static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev) 225 { 226 return st_uvis25_set_enable(iio_priv(iio_dev), false); 227 } 228 229 static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = { 230 .preenable = st_uvis25_buffer_preenable, 231 .postenable = iio_triggered_buffer_postenable, 232 .predisable = iio_triggered_buffer_predisable, 233 .postdisable = st_uvis25_buffer_postdisable, 234 }; 235 236 static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p) 237 { 238 u8 buffer[ALIGN(sizeof(u8), sizeof(s64)) + sizeof(s64)]; 239 struct iio_poll_func *pf = p; 240 struct iio_dev *iio_dev = pf->indio_dev; 241 struct st_uvis25_hw *hw = iio_priv(iio_dev); 242 int err; 243 244 err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer); 245 if (err < 0) 246 goto out; 247 248 iio_push_to_buffers_with_timestamp(iio_dev, buffer, 249 iio_get_time_ns(iio_dev)); 250 251 out: 252 iio_trigger_notify_done(hw->trig); 253 254 return IRQ_HANDLED; 255 } 256 257 static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev) 258 { 259 struct st_uvis25_hw *hw = iio_priv(iio_dev); 260 261 return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap), 262 iio_dev, NULL, 263 st_uvis25_buffer_handler_thread, 264 &st_uvis25_buffer_ops); 265 } 266 267 static const struct iio_info st_uvis25_info = { 268 .read_raw = st_uvis25_read_raw, 269 }; 270 271 static int st_uvis25_init_sensor(struct st_uvis25_hw *hw) 272 { 273 int err; 274 275 err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR, 276 ST_UVIS25_REG_BOOT_MASK, 1); 277 if (err < 0) 278 return err; 279 280 msleep(2000); 281 282 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 283 ST_UVIS25_REG_BDU_MASK, 1); 284 } 285 286 int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap) 287 { 288 struct st_uvis25_hw *hw; 289 struct iio_dev *iio_dev; 290 int err; 291 292 iio_dev = devm_iio_device_alloc(dev, sizeof(*hw)); 293 if (!iio_dev) 294 return -ENOMEM; 295 296 dev_set_drvdata(dev, (void *)iio_dev); 297 298 hw = iio_priv(iio_dev); 299 hw->irq = irq; 300 hw->regmap = regmap; 301 302 err = st_uvis25_check_whoami(hw); 303 if (err < 0) 304 return err; 305 306 iio_dev->modes = INDIO_DIRECT_MODE; 307 iio_dev->dev.parent = dev; 308 iio_dev->channels = st_uvis25_channels; 309 iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels); 310 iio_dev->name = ST_UVIS25_DEV_NAME; 311 iio_dev->info = &st_uvis25_info; 312 313 err = st_uvis25_init_sensor(hw); 314 if (err < 0) 315 return err; 316 317 if (hw->irq > 0) { 318 err = st_uvis25_allocate_buffer(iio_dev); 319 if (err < 0) 320 return err; 321 322 err = st_uvis25_allocate_trigger(iio_dev); 323 if (err) 324 return err; 325 } 326 327 return devm_iio_device_register(dev, iio_dev); 328 } 329 EXPORT_SYMBOL(st_uvis25_probe); 330 331 static int __maybe_unused st_uvis25_suspend(struct device *dev) 332 { 333 struct iio_dev *iio_dev = dev_get_drvdata(dev); 334 struct st_uvis25_hw *hw = iio_priv(iio_dev); 335 336 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 337 ST_UVIS25_REG_ODR_MASK, 0); 338 } 339 340 static int __maybe_unused st_uvis25_resume(struct device *dev) 341 { 342 struct iio_dev *iio_dev = dev_get_drvdata(dev); 343 struct st_uvis25_hw *hw = iio_priv(iio_dev); 344 345 if (hw->enabled) 346 return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR, 347 ST_UVIS25_REG_ODR_MASK, 1); 348 349 return 0; 350 } 351 352 const struct dev_pm_ops st_uvis25_pm_ops = { 353 SET_SYSTEM_SLEEP_PM_OPS(st_uvis25_suspend, st_uvis25_resume) 354 }; 355 EXPORT_SYMBOL(st_uvis25_pm_ops); 356 357 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>"); 358 MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver"); 359 MODULE_LICENSE("GPL v2"); 360