drivers/iio/light/st_uvis25_core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * STMicroelectronics uvis25 sensor driver
  *
  * Copyright 2017 STMicroelectronics Inc.
  *
  * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/iio/sysfs.h>
 #include <linux/delay.h>
 #include <linux/pm.h>
 #include <linux/interrupt.h>
 #include <linux/irqreturn.h>
 #include <linux/iio/trigger.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/buffer.h>
 #include <linux/regmap.h>

 #include "st_uvis25.h"

 #define ST_UVIS25_REG_WHOAMI_ADDR	0x0f
 #define ST_UVIS25_REG_WHOAMI_VAL	0xca
 #define ST_UVIS25_REG_CTRL1_ADDR	0x20
 #define ST_UVIS25_REG_ODR_MASK		BIT(0)
 #define ST_UVIS25_REG_BDU_MASK		BIT(1)
 #define ST_UVIS25_REG_CTRL2_ADDR	0x21
 #define ST_UVIS25_REG_BOOT_MASK		BIT(7)
 #define ST_UVIS25_REG_CTRL3_ADDR	0x22
 #define ST_UVIS25_REG_HL_MASK		BIT(7)
 #define ST_UVIS25_REG_STATUS_ADDR	0x27
 #define ST_UVIS25_REG_UV_DA_MASK	BIT(0)
 #define ST_UVIS25_REG_OUT_ADDR		0x28

 static const struct iio_chan_spec st_uvis25_channels[] = {
 	{
 		.type = IIO_UVINDEX,
 		.address = ST_UVIS25_REG_OUT_ADDR,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 		.scan_index = 0,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 8,
 			.storagebits = 8,
 		},
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(1),
 };

 static int st_uvis25_check_whoami(struct st_uvis25_hw *hw)
 {
 	int err, data;

 	err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data);
 	if (err < 0) {
 		dev_err(regmap_get_device(hw->regmap),
 			"failed to read whoami register\n");
 		return err;
 	}

 	if (data != ST_UVIS25_REG_WHOAMI_VAL) {
 		dev_err(regmap_get_device(hw->regmap),
 			"wrong whoami {%02x vs %02x}\n",
 			data, ST_UVIS25_REG_WHOAMI_VAL);
 		return -ENODEV;
 	}

 	return 0;
 }

 static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable)
 {
 	int err;

 	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
 				 ST_UVIS25_REG_ODR_MASK, enable);
 	if (err < 0)
 		return err;

 	hw->enabled = enable;

 	return 0;
 }

 static int st_uvis25_read_oneshot(struct st_uvis25_hw *hw, u8 addr, int *val)
 {
 	int err;

 	err = st_uvis25_set_enable(hw, true);
 	if (err < 0)
 		return err;

 	msleep(1500);

 	/*
 	 * in order to avoid possible race conditions with interrupt
 	 * generation, disable the sensor first and then poll output
 	 * register. That sequence guarantees the interrupt will be reset
 	 * when irq line is unmasked
 	 */
 	err = st_uvis25_set_enable(hw, false);
 	if (err < 0)
 		return err;

 	err = regmap_read(hw->regmap, addr, val);

 	return err < 0 ? err : IIO_VAL_INT;
 }

 static int st_uvis25_read_raw(struct iio_dev *iio_dev,
 			      struct iio_chan_spec const *ch,
 			      int *val, int *val2, long mask)
 {
 	int ret;

 	ret = iio_device_claim_direct_mode(iio_dev);
 	if (ret)
 		return ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED: {
 		struct st_uvis25_hw *hw = iio_priv(iio_dev);

 		/*
 		 * mask irq line during oneshot read since the sensor
 		 * does not export the capability to disable data-ready line
 		 * in the register map and it is enabled by default.
 		 * If the line is unmasked during read_raw() it will be set
 		 * active and never reset since the trigger is disabled
 		 */
 		if (hw->irq > 0)
 			disable_irq(hw->irq);
 		ret = st_uvis25_read_oneshot(hw, ch->address, val);
 		if (hw->irq > 0)
 			enable_irq(hw->irq);
 		break;
 	}
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	iio_device_release_direct_mode(iio_dev);

 	return ret;
 }

 static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private)
 {
 	struct st_uvis25_hw *hw = private;
 	int err, status;

 	err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status);
 	if (err < 0)
 		return IRQ_HANDLED;

 	if (!(status & ST_UVIS25_REG_UV_DA_MASK))
 		return IRQ_NONE;

 	iio_trigger_poll_nested(hw->trig);

 	return IRQ_HANDLED;
 }

 static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev)
 {
 	struct st_uvis25_hw *hw = iio_priv(iio_dev);
 	struct device *dev = regmap_get_device(hw->regmap);
 	bool irq_active_low = false;
 	unsigned long irq_type;
 	int err;

 	irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));

 	switch (irq_type) {
 	case IRQF_TRIGGER_HIGH:
 	case IRQF_TRIGGER_RISING:
 		break;
 	case IRQF_TRIGGER_LOW:
 	case IRQF_TRIGGER_FALLING:
 		irq_active_low = true;
 		break;
 	default:
 		dev_info(dev, "mode %lx unsupported\n", irq_type);
 		return -EINVAL;
 	}

 	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
 				 ST_UVIS25_REG_HL_MASK, irq_active_low);
 	if (err < 0)
 		return err;

 	err = devm_request_threaded_irq(dev, hw->irq, NULL,
 					st_uvis25_trigger_handler_thread,
 					irq_type | IRQF_ONESHOT,
 					iio_dev->name, hw);
 	if (err) {
 		dev_err(dev, "failed to request trigger irq %d\n",
 			hw->irq);
 		return err;
 	}

 	hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
 					  iio_dev->name);
 	if (!hw->trig)
 		return -ENOMEM;

 	iio_trigger_set_drvdata(hw->trig, iio_dev);

 	return devm_iio_trigger_register(dev, hw->trig);
 }

 static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
 {
 	return st_uvis25_set_enable(iio_priv(iio_dev), true);
 }

 static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
 {
 	return st_uvis25_set_enable(iio_priv(iio_dev), false);
 }

 static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
 	.preenable = st_uvis25_buffer_preenable,
 	.postdisable = st_uvis25_buffer_postdisable,
 };

 static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *iio_dev = pf->indio_dev;
 	struct st_uvis25_hw *hw = iio_priv(iio_dev);
 	unsigned int val;
 	int err;

 	err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val);
 	if (err < 0)
 		goto out;

 	hw->scan.chan = val;

 	iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
 					   iio_get_time_ns(iio_dev));

 out:
 	iio_trigger_notify_done(hw->trig);

 	return IRQ_HANDLED;
 }

 static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
 {
 	struct st_uvis25_hw *hw = iio_priv(iio_dev);

 	return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
 					       iio_dev, NULL,
 					       st_uvis25_buffer_handler_thread,
 					       &st_uvis25_buffer_ops);
 }

 static const struct iio_info st_uvis25_info = {
 	.read_raw = st_uvis25_read_raw,
 };

 static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
 {
 	int err;

 	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
 				 ST_UVIS25_REG_BOOT_MASK, 1);
 	if (err < 0)
 		return err;

 	msleep(2000);

 	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
 				  ST_UVIS25_REG_BDU_MASK, 1);
 }

 int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap)
 {
 	struct st_uvis25_hw *hw;
 	struct iio_dev *iio_dev;
 	int err;

 	iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
 	if (!iio_dev)
 		return -ENOMEM;

 	dev_set_drvdata(dev, (void *)iio_dev);

 	hw = iio_priv(iio_dev);
 	hw->irq = irq;
 	hw->regmap = regmap;

 	err = st_uvis25_check_whoami(hw);
 	if (err < 0)
 		return err;

 	iio_dev->modes = INDIO_DIRECT_MODE;
 	iio_dev->channels = st_uvis25_channels;
 	iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
 	iio_dev->name = ST_UVIS25_DEV_NAME;
 	iio_dev->info = &st_uvis25_info;

 	err = st_uvis25_init_sensor(hw);
 	if (err < 0)
 		return err;

 	if (hw->irq > 0) {
 		err = st_uvis25_allocate_buffer(iio_dev);
 		if (err < 0)
 			return err;

 		err = st_uvis25_allocate_trigger(iio_dev);
 		if (err)
 			return err;
 	}

 	return devm_iio_device_register(dev, iio_dev);
 }
 EXPORT_SYMBOL_NS(st_uvis25_probe, IIO_UVIS25);

 static int st_uvis25_suspend(struct device *dev)
 {
 	struct iio_dev *iio_dev = dev_get_drvdata(dev);
 	struct st_uvis25_hw *hw = iio_priv(iio_dev);

 	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
 				  ST_UVIS25_REG_ODR_MASK, 0);
 }

 static int st_uvis25_resume(struct device *dev)
 {
 	struct iio_dev *iio_dev = dev_get_drvdata(dev);
 	struct st_uvis25_hw *hw = iio_priv(iio_dev);

 	if (hw->enabled)
 		return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
 					  ST_UVIS25_REG_ODR_MASK, 1);

 	return 0;
 }

 EXPORT_NS_SIMPLE_DEV_PM_OPS(st_uvis25_pm_ops, st_uvis25_suspend, st_uvis25_resume, IIO_UVIS25);

 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
 MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* STMicroelectronics uvis25 sensor driver
	*
	* Copyright 2017 STMicroelectronics Inc.
	*
	* Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/device.h>
	#include <linux/iio/sysfs.h>
	#include <linux/delay.h>
	#include <linux/pm.h>
	#include <linux/interrupt.h>
	#include <linux/irqreturn.h>
	#include <linux/iio/trigger.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/iio/buffer.h>
	#include <linux/regmap.h>

	#include "st_uvis25.h"

	#define ST_UVIS25_REG_WHOAMI_ADDR 0x0f
	#define ST_UVIS25_REG_WHOAMI_VAL 0xca
	#define ST_UVIS25_REG_CTRL1_ADDR 0x20
	#define ST_UVIS25_REG_ODR_MASK BIT(0)
	#define ST_UVIS25_REG_BDU_MASK BIT(1)
	#define ST_UVIS25_REG_CTRL2_ADDR 0x21
	#define ST_UVIS25_REG_BOOT_MASK BIT(7)
	#define ST_UVIS25_REG_CTRL3_ADDR 0x22
	#define ST_UVIS25_REG_HL_MASK BIT(7)
	#define ST_UVIS25_REG_STATUS_ADDR 0x27
	#define ST_UVIS25_REG_UV_DA_MASK BIT(0)
	#define ST_UVIS25_REG_OUT_ADDR 0x28

	static const struct iio_chan_spec st_uvis25_channels[] = {
	{
	.type = IIO_UVINDEX,
	.address = ST_UVIS25_REG_OUT_ADDR,
	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	.scan_index = 0,
	.scan_type = {
	.sign = 'u',
	.realbits = 8,
	.storagebits = 8,
	},
	},
	IIO_CHAN_SOFT_TIMESTAMP(1),
	};

	static int st_uvis25_check_whoami(struct st_uvis25_hw *hw)
	{
	int err, data;

	err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data);
	if (err < 0) {
	dev_err(regmap_get_device(hw->regmap),
	"failed to read whoami register\n");
	return err;
	}

	if (data != ST_UVIS25_REG_WHOAMI_VAL) {
	dev_err(regmap_get_device(hw->regmap),
	"wrong whoami {%02x vs %02x}\n",
	data, ST_UVIS25_REG_WHOAMI_VAL);
	return -ENODEV;
	}

	return 0;
	}

	static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable)
	{
	int err;

	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
	ST_UVIS25_REG_ODR_MASK, enable);
	if (err < 0)
	return err;

	hw->enabled = enable;

	return 0;
	}

	static int st_uvis25_read_oneshot(struct st_uvis25_hw hw, u8 addr, int val)
	{
	int err;

	err = st_uvis25_set_enable(hw, true);
	if (err < 0)
	return err;

	msleep(1500);

	/*
	* in order to avoid possible race conditions with interrupt
	* generation, disable the sensor first and then poll output
	* register. That sequence guarantees the interrupt will be reset
	* when irq line is unmasked
	*/
	err = st_uvis25_set_enable(hw, false);
	if (err < 0)
	return err;

	err = regmap_read(hw->regmap, addr, val);

	return err < 0 ? err : IIO_VAL_INT;
	}

	static int st_uvis25_read_raw(struct iio_dev *iio_dev,
	struct iio_chan_spec const *ch,
	int val, int val2, long mask)
	{
	int ret;

	ret = iio_device_claim_direct_mode(iio_dev);
	if (ret)
	return ret;

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED: {
	struct st_uvis25_hw *hw = iio_priv(iio_dev);

	/*
	* mask irq line during oneshot read since the sensor
	* does not export the capability to disable data-ready line
	* in the register map and it is enabled by default.
	* If the line is unmasked during read_raw() it will be set
	* active and never reset since the trigger is disabled
	*/
	if (hw->irq > 0)
	disable_irq(hw->irq);
	ret = st_uvis25_read_oneshot(hw, ch->address, val);
	if (hw->irq > 0)
	enable_irq(hw->irq);
	break;
	}
	default:
	ret = -EINVAL;
	break;
	}

	iio_device_release_direct_mode(iio_dev);

	return ret;
	}

	static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private)
	{
	struct st_uvis25_hw *hw = private;
	int err, status;

	err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status);
	if (err < 0)
	return IRQ_HANDLED;

	if (!(status & ST_UVIS25_REG_UV_DA_MASK))
	return IRQ_NONE;

	iio_trigger_poll_nested(hw->trig);

	return IRQ_HANDLED;
	}

	static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev)
	{
	struct st_uvis25_hw *hw = iio_priv(iio_dev);
	struct device *dev = regmap_get_device(hw->regmap);
	bool irq_active_low = false;
	unsigned long irq_type;
	int err;

	irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));

	switch (irq_type) {
	case IRQF_TRIGGER_HIGH:
	case IRQF_TRIGGER_RISING:
	break;
	case IRQF_TRIGGER_LOW:
	case IRQF_TRIGGER_FALLING:
	irq_active_low = true;
	break;
	default:
	dev_info(dev, "mode %lx unsupported\n", irq_type);
	return -EINVAL;
	}

	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
	ST_UVIS25_REG_HL_MASK, irq_active_low);
	if (err < 0)
	return err;

	err = devm_request_threaded_irq(dev, hw->irq, NULL,
	st_uvis25_trigger_handler_thread,
	irq_type \| IRQF_ONESHOT,
	iio_dev->name, hw);
	if (err) {
	dev_err(dev, "failed to request trigger irq %d\n",
	hw->irq);
	return err;
	}

	hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
	iio_dev->name);
	if (!hw->trig)
	return -ENOMEM;

	iio_trigger_set_drvdata(hw->trig, iio_dev);

	return devm_iio_trigger_register(dev, hw->trig);
	}

	static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
	{
	return st_uvis25_set_enable(iio_priv(iio_dev), true);
	}

	static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
	{
	return st_uvis25_set_enable(iio_priv(iio_dev), false);
	}

	static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
	.preenable = st_uvis25_buffer_preenable,
	.postdisable = st_uvis25_buffer_postdisable,
	};

	static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *iio_dev = pf->indio_dev;
	struct st_uvis25_hw *hw = iio_priv(iio_dev);
	unsigned int val;
	int err;

	err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val);
	if (err < 0)
	goto out;

	hw->scan.chan = val;

	iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
	iio_get_time_ns(iio_dev));

	out:
	iio_trigger_notify_done(hw->trig);

	return IRQ_HANDLED;
	}

	static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
	{
	struct st_uvis25_hw *hw = iio_priv(iio_dev);

	return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
	iio_dev, NULL,
	st_uvis25_buffer_handler_thread,
	&st_uvis25_buffer_ops);
	}

	static const struct iio_info st_uvis25_info = {
	.read_raw = st_uvis25_read_raw,
	};

	static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
	{
	int err;

	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
	ST_UVIS25_REG_BOOT_MASK, 1);
	if (err < 0)
	return err;

	msleep(2000);

	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
	ST_UVIS25_REG_BDU_MASK, 1);
	}

	int st_uvis25_probe(struct device dev, int irq, struct regmap regmap)
	{
	struct st_uvis25_hw *hw;
	struct iio_dev *iio_dev;
	int err;

	iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
	if (!iio_dev)
	return -ENOMEM;

	dev_set_drvdata(dev, (void *)iio_dev);

	hw = iio_priv(iio_dev);
	hw->irq = irq;
	hw->regmap = regmap;

	err = st_uvis25_check_whoami(hw);
	if (err < 0)
	return err;

	iio_dev->modes = INDIO_DIRECT_MODE;
	iio_dev->channels = st_uvis25_channels;
	iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
	iio_dev->name = ST_UVIS25_DEV_NAME;
	iio_dev->info = &st_uvis25_info;

	err = st_uvis25_init_sensor(hw);
	if (err < 0)
	return err;

	if (hw->irq > 0) {
	err = st_uvis25_allocate_buffer(iio_dev);
	if (err < 0)
	return err;

	err = st_uvis25_allocate_trigger(iio_dev);
	if (err)
	return err;
	}

	return devm_iio_device_register(dev, iio_dev);
	}
	EXPORT_SYMBOL_NS(st_uvis25_probe, IIO_UVIS25);

	static int st_uvis25_suspend(struct device *dev)
	{
	struct iio_dev *iio_dev = dev_get_drvdata(dev);
	struct st_uvis25_hw *hw = iio_priv(iio_dev);

	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
	ST_UVIS25_REG_ODR_MASK, 0);
	}

	static int st_uvis25_resume(struct device *dev)
	{
	struct iio_dev *iio_dev = dev_get_drvdata(dev);
	struct st_uvis25_hw *hw = iio_priv(iio_dev);

	if (hw->enabled)
	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
	ST_UVIS25_REG_ODR_MASK, 1);

	return 0;
	}

	EXPORT_NS_SIMPLE_DEV_PM_OPS(st_uvis25_pm_ops, st_uvis25_suspend, st_uvis25_resume, IIO_UVIS25);

	MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
	MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
	MODULE_LICENSE("GPL v2");