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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * STMicroelectronics uvis25 sensor driver4 *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 0x0f27#define ST_UVIS25_REG_WHOAMI_VAL 0xca28#define ST_UVIS25_REG_CTRL1_ADDR 0x2029#define ST_UVIS25_REG_ODR_MASK BIT(0)30#define ST_UVIS25_REG_BDU_MASK BIT(1)31#define ST_UVIS25_REG_CTRL2_ADDR 0x2132#define ST_UVIS25_REG_BOOT_MASK BIT(7)33#define ST_UVIS25_REG_CTRL3_ADDR 0x2234#define ST_UVIS25_REG_HL_MASK BIT(7)35#define ST_UVIS25_REG_STATUS_ADDR 0x2736#define ST_UVIS25_REG_UV_DA_MASK BIT(0)37#define ST_UVIS25_REG_OUT_ADDR 0x2838 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 interrupt101 * generation, disable the sensor first and then poll output102 * register. That sequence guarantees the interrupt will be reset103 * when irq line is unmasked104 */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 sensor130 * does not export the capability to disable data-ready line131 * in the register map and it is enabled by default.132 * If the line is unmasked during read_raw() it will be set133 * active and never reset since the trigger is disabled134 */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 = 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 217static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)218{219 return st_uvis25_set_enable(iio_priv(iio_dev), true);220}221 222static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)223{224 return st_uvis25_set_enable(iio_priv(iio_dev), false);225}226 227static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {228 .preenable = st_uvis25_buffer_preenable,229 .postdisable = st_uvis25_buffer_postdisable,230};231 232static 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 249out:250 iio_trigger_notify_done(hw->trig);251 252 return IRQ_HANDLED;253}254 255static 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 265static const struct iio_info st_uvis25_info = {266 .read_raw = st_uvis25_read_raw,267};268 269static 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 284int 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, 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}326EXPORT_SYMBOL_NS(st_uvis25_probe, IIO_UVIS25);327 328static 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_clear_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,334 ST_UVIS25_REG_ODR_MASK);335}336 337static 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 349EXPORT_NS_SIMPLE_DEV_PM_OPS(st_uvis25_pm_ops, st_uvis25_suspend, st_uvis25_resume, IIO_UVIS25);350 351MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");352MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");353MODULE_LICENSE("GPL v2");354