Commit 059c53b3 authored by Marek Vasut's avatar Marek Vasut Committed by Jonathan Cameron
Browse files

iio: adc: Add Renesas GyroADC driver 



Add IIO driver for the Renesas RCar GyroADC block. This block is a
simple 4/8-channel ADC which samples 12/15/24 bits of data every
cycle from all channels.

Signed-off-by: default avatarMarek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent ec2ef153

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -10439,6 +10439,12 @@ L: linux-renesas-soc@vger.kernel.org 
F:	drivers/net/ethernet/renesas/

F:	include/linux/sh_eth.h



RENESAS R-CAR GYROADC DRIVER

M:	Marek Vasut <marek.vasut@gmail.com>

L:	linux-iio@vger.kernel.org

S:	Supported

F:	drivers/iio/adc/rcar_gyro_adc.c



RENESAS USB2 PHY DRIVER

M:	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

L:	linux-renesas-soc@vger.kernel.org

drivers/iio/adc/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -458,6 +458,19 @@ config QCOM_SPMI_VADC 
	  To compile this driver as a module, choose M here: the module will

	  be called qcom-spmi-vadc.



config RCAR_GYRO_ADC

	tristate "Renesas R-Car GyroADC driver"

	depends on ARCH_RCAR_GEN2 || (ARM && COMPILE_TEST)

	help

	  Say yes here to build support for the GyroADC found in Renesas

	  R-Car Gen2 SoCs. This block is a simple SPI offload engine for

	  reading data out of attached compatible ADCs in a round-robin

	  fashion. Up to 4 or 8 ADC channels are supported by this block,

	  depending on which ADCs are attached.



	  To compile this driver as a module, choose M here: the

	  module will be called rcar-gyroadc.



config ROCKCHIP_SARADC

	tristate "Rockchip SARADC driver"

	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)

drivers/iio/adc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ obj-$(CONFIG_NAU7802) += nau7802.o 
obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o

obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o

obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o

obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o

obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o

obj-$(CONFIG_STX104) += stx104.o

obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o

drivers/iio/adc/rcar-gyroadc.c

0 → 100644
+631 −0
Original line number Diff line number Diff line 
/*

 * Renesas R-Car GyroADC driver

 *

 * Copyright 2016 Marek Vasut <marek.vasut@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 */



#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/delay.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/io.h>

#include <linux/clk.h>

#include <linux/of.h>

#include <linux/of_irq.h>

#include <linux/regulator/consumer.h>

#include <linux/of_platform.h>

#include <linux/err.h>

#include <linux/pm_runtime.h>



#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/trigger.h>



#define DRIVER_NAME				"rcar-gyroadc"



/* GyroADC registers. */

#define RCAR_GYROADC_MODE_SELECT		0x00

#define RCAR_GYROADC_MODE_SELECT_1_MB88101A	0x0

#define RCAR_GYROADC_MODE_SELECT_2_ADCS7476	0x1

#define RCAR_GYROADC_MODE_SELECT_3_MAX1162	0x3



#define RCAR_GYROADC_START_STOP			0x04

#define RCAR_GYROADC_START_STOP_START		BIT(0)



#define RCAR_GYROADC_CLOCK_LENGTH		0x08

#define RCAR_GYROADC_1_25MS_LENGTH		0x0c



#define RCAR_GYROADC_REALTIME_DATA(ch)		(0x10 + ((ch) * 4))

#define RCAR_GYROADC_100MS_ADDED_DATA(ch)	(0x30 + ((ch) * 4))

#define RCAR_GYROADC_10MS_AVG_DATA(ch)		(0x50 + ((ch) * 4))



#define RCAR_GYROADC_FIFO_STATUS		0x70

#define RCAR_GYROADC_FIFO_STATUS_EMPTY(ch)	BIT(0 + (4 * (ch)))

#define RCAR_GYROADC_FIFO_STATUS_FULL(ch)	BIT(1 + (4 * (ch)))

#define RCAR_GYROADC_FIFO_STATUS_ERROR(ch)	BIT(2 + (4 * (ch)))



#define RCAR_GYROADC_INTR			0x74

#define RCAR_GYROADC_INTR_INT			BIT(0)



#define RCAR_GYROADC_INTENR			0x78

#define RCAR_GYROADC_INTENR_INTEN		BIT(0)



#define RCAR_GYROADC_SAMPLE_RATE		800	/* Hz */



#define RCAR_GYROADC_RUNTIME_PM_DELAY_MS	2000



enum rcar_gyroadc_model {

	RCAR_GYROADC_MODEL_DEFAULT,

	RCAR_GYROADC_MODEL_R8A7792,

};



struct rcar_gyroadc {

	struct device			*dev;

	void __iomem			*regs;

	struct clk			*iclk;

	struct regulator		*vref[8];

	unsigned int			num_channels;

	enum rcar_gyroadc_model		model;

	unsigned int			mode;

	unsigned int			sample_width;

};



static void rcar_gyroadc_hw_init(struct rcar_gyroadc *priv)

{

	const unsigned long clk_mhz = clk_get_rate(priv->iclk) / 1000000;

	const unsigned long clk_mul =

		(priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) ? 10 : 5;

	unsigned long clk_len = clk_mhz * clk_mul;



	/*

	 * According to the R-Car Gen2 datasheet Rev. 1.01, Sept 08 2014,

	 * page 77-7, clock length must be even number. If it's odd number,

	 * add one.

	 */

	if (clk_len & 1)

		clk_len++;



	/* Stop the GyroADC. */

	writel(0, priv->regs + RCAR_GYROADC_START_STOP);



	/* Disable IRQ on V2H. */

	if (priv->model == RCAR_GYROADC_MODEL_R8A7792)

		writel(0, priv->regs + RCAR_GYROADC_INTENR);



	/* Set mode and timing. */

	writel(priv->mode, priv->regs + RCAR_GYROADC_MODE_SELECT);

	writel(clk_len, priv->regs + RCAR_GYROADC_CLOCK_LENGTH);

	writel(clk_mhz * 1250, priv->regs + RCAR_GYROADC_1_25MS_LENGTH);

}



static void rcar_gyroadc_hw_start(struct rcar_gyroadc *priv)

{

	/* Start sampling. */

	writel(RCAR_GYROADC_START_STOP_START,

	       priv->regs + RCAR_GYROADC_START_STOP);



	/*

	 * Wait for the first conversion to complete. This is longer than

	 * the 1.25 mS in the datasheet because 1.25 mS is not enough for

	 * the hardware to deliver the first sample and the hardware does

	 * then return zeroes instead of valid data.

	 */

	mdelay(3);

}



static void rcar_gyroadc_hw_stop(struct rcar_gyroadc *priv)

{

	/* Stop the GyroADC. */

	writel(0, priv->regs + RCAR_GYROADC_START_STOP);

}



#define RCAR_GYROADC_CHAN(_idx) {				\

	.type			= IIO_VOLTAGE,			\

	.indexed		= 1,				\

	.channel		= (_idx),			\

	.info_mask_separate	= BIT(IIO_CHAN_INFO_RAW) |	\

				  BIT(IIO_CHAN_INFO_SCALE),	\

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \

}



static const struct iio_chan_spec rcar_gyroadc_iio_channels_1[] = {

	RCAR_GYROADC_CHAN(0),

	RCAR_GYROADC_CHAN(1),

	RCAR_GYROADC_CHAN(2),

	RCAR_GYROADC_CHAN(3),

};



static const struct iio_chan_spec rcar_gyroadc_iio_channels_2[] = {

	RCAR_GYROADC_CHAN(0),

	RCAR_GYROADC_CHAN(1),

	RCAR_GYROADC_CHAN(2),

	RCAR_GYROADC_CHAN(3),

	RCAR_GYROADC_CHAN(4),

	RCAR_GYROADC_CHAN(5),

	RCAR_GYROADC_CHAN(6),

	RCAR_GYROADC_CHAN(7),

};



static const struct iio_chan_spec rcar_gyroadc_iio_channels_3[] = {

	RCAR_GYROADC_CHAN(0),

	RCAR_GYROADC_CHAN(1),

	RCAR_GYROADC_CHAN(2),

	RCAR_GYROADC_CHAN(3),

	RCAR_GYROADC_CHAN(4),

	RCAR_GYROADC_CHAN(5),

	RCAR_GYROADC_CHAN(6),

	RCAR_GYROADC_CHAN(7),

};



static int rcar_gyroadc_set_power(struct rcar_gyroadc *priv, bool on)

{

	struct device *dev = priv->dev;

	int ret;



	if (on) {

		ret = pm_runtime_get_sync(dev);

		if (ret < 0)

			pm_runtime_put_noidle(dev);

	} else {

		pm_runtime_mark_last_busy(dev);

		ret = pm_runtime_put_autosuspend(dev);

	}



	return ret;

}



static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev,

				 struct iio_chan_spec const *chan,

				 int *val, int *val2, long mask)

{

	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	struct regulator *consumer;

	unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel);

	unsigned int vref;

	int ret;



	/*

	 * MB88101 is special in that it has only single regulator for

	 * all four channels.

	 */

	if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)

		consumer = priv->vref[0];

	else

		consumer = priv->vref[chan->channel];



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (chan->type != IIO_VOLTAGE)

			return -EINVAL;



		/* Channel not connected. */

		if (!consumer)

			return -EINVAL;



		ret = iio_device_claim_direct_mode(indio_dev);

		if (ret)

			return ret;



		ret = rcar_gyroadc_set_power(priv, true);

		if (ret < 0) {

			iio_device_release_direct_mode(indio_dev);

			return ret;

		}



		*val = readl(priv->regs + datareg);

		*val &= BIT(priv->sample_width) - 1;



		ret = rcar_gyroadc_set_power(priv, false);

		iio_device_release_direct_mode(indio_dev);

		if (ret < 0)

			return ret;



		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		/* Channel not connected. */

		if (!consumer)

			return -EINVAL;



		vref = regulator_get_voltage(consumer);

		*val = vref / 1000;

		*val2 = 1 << priv->sample_width;



		return IIO_VAL_FRACTIONAL;

	case IIO_CHAN_INFO_SAMP_FREQ:

		*val = RCAR_GYROADC_SAMPLE_RATE;



		return IIO_VAL_INT;

	default:

		return -EINVAL;

	}

}



static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev,

				   unsigned int reg, unsigned int writeval,

				   unsigned int *readval)

{

	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS;



	if (readval == NULL)

		return -EINVAL;



	if (reg % 4)

		return -EINVAL;



	/* Handle the V2H case with extra interrupt block. */

	if (priv->model == RCAR_GYROADC_MODEL_R8A7792)

		maxreg = RCAR_GYROADC_INTENR;



	if (reg > maxreg)

		return -EINVAL;



	*readval = readl(priv->regs + reg);



	return 0;

}



static const struct iio_info rcar_gyroadc_iio_info = {

	.driver_module		= THIS_MODULE,

	.read_raw		= rcar_gyroadc_read_raw,

	.debugfs_reg_access	= rcar_gyroadc_reg_access,

};



static const struct of_device_id rcar_gyroadc_match[] = {

	{

		/* R-Car compatible GyroADC */

		.compatible	= "renesas,rcar-gyroadc",

		.data		= (void *)RCAR_GYROADC_MODEL_DEFAULT,

	}, {

		/* R-Car V2H specialty with interrupt registers. */

		.compatible	= "renesas,r8a7792-gyroadc",

		.data		= (void *)RCAR_GYROADC_MODEL_R8A7792,

	}, {

		/* sentinel */

	}

};



MODULE_DEVICE_TABLE(of, rcar_gyroadc_match);



static const struct of_device_id rcar_gyroadc_child_match[] = {

	/* Mode 1 ADCs */

	{

		.compatible	= "fujitsu,mb88101a",

		.data		= (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A,

	},

	/* Mode 2 ADCs */

	{

		.compatible	= "ti,adcs7476",

		.data		= (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,

	}, {

		.compatible	= "ti,adc121",

		.data		= (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,

	}, {

		.compatible	= "adi,ad7476",

		.data		= (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,

	},

	/* Mode 3 ADCs */

	{

		.compatible	= "maxim,max1162",

		.data		= (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,

	}, {

		.compatible	= "maxim,max11100",

		.data		= (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,

	},

	{ /* sentinel */ }

};



static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)

{

	const struct of_device_id *of_id;

	const struct iio_chan_spec *channels;

	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	struct device *dev = priv->dev;

	struct device_node *np = dev->of_node;

	struct device_node *child;

	struct regulator *vref;

	unsigned int reg;

	unsigned int adcmode, childmode;

	unsigned int sample_width;

	unsigned int num_channels;

	int ret, first = 1;



	for_each_child_of_node(np, child) {

		of_id = of_match_node(rcar_gyroadc_child_match, child);

		if (!of_id) {

			dev_err(dev, "Ignoring unsupported ADC \"%s\".",

				child->name);

			continue;

		}



		childmode = (unsigned int)of_id->data;

		switch (childmode) {

		case RCAR_GYROADC_MODE_SELECT_1_MB88101A:

			sample_width = 12;

			channels = rcar_gyroadc_iio_channels_1;

			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1);

			break;

		case RCAR_GYROADC_MODE_SELECT_2_ADCS7476:

			sample_width = 15;

			channels = rcar_gyroadc_iio_channels_2;

			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2);

			break;

		case RCAR_GYROADC_MODE_SELECT_3_MAX1162:

			sample_width = 16;

			channels = rcar_gyroadc_iio_channels_3;

			num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);

			break;

		}



		/*

		 * MB88101 is special in that it's only a single chip taking

		 * up all the CHS lines. Thus, the DT binding is also special

		 * and has no reg property. If we run into such ADC, handle

		 * it here.

		 */

		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {

			reg = 0;

		} else {

			ret = of_property_read_u32(child, "reg", &reg);

			if (ret) {

				dev_err(dev,

					"Failed to get child reg property of ADC \"%s\".\n",

					child->name);

				return ret;

			}



			/* Channel number is too high. */

			if (reg >= num_channels) {

				dev_err(dev,

					"Only %i channels supported with %s, but reg = <%i>.\n",

					num_channels, child->name, reg);

				return ret;

			}

		}



		/* Child node selected different mode than the rest. */

		if (!first && (adcmode != childmode)) {

			dev_err(dev,

				"Channel %i uses different ADC mode than the rest.\n",

				reg);

			return ret;

		}



		/* Channel is valid, grab the regulator. */

		dev->of_node = child;

		vref = devm_regulator_get(dev, "vref");

		dev->of_node = np;

		if (IS_ERR(vref)) {

			dev_dbg(dev, "Channel %i 'vref' supply not connected.\n",

				reg);

			return PTR_ERR(vref);

		}



		priv->vref[reg] = vref;



		if (!first)

			continue;



		/* First child node which passed sanity tests. */

		adcmode = childmode;

		first = 0;



		priv->num_channels = num_channels;

		priv->mode = childmode;

		priv->sample_width = sample_width;



		indio_dev->channels = channels;

		indio_dev->num_channels = num_channels;



		/*

		 * MB88101 is special and we only have one such device

		 * attached to the GyroADC at a time, so if we found it,

		 * we can stop parsing here.

		 */

		if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)

			break;

	}



	if (first) {

		dev_err(dev, "No valid ADC channels found, aborting.\n");

		return -EINVAL;

	}



	return 0;

}



static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev)

{

	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	unsigned int i;



	for (i = 0; i < priv->num_channels; i++) {

		if (!priv->vref[i])

			continue;



		regulator_disable(priv->vref[i]);

	}

}



static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev)

{

	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	struct device *dev = priv->dev;

	unsigned int i;

	int ret;



	for (i = 0; i < priv->num_channels; i++) {

		if (!priv->vref[i])

			continue;



		ret = regulator_enable(priv->vref[i]);

		if (ret) {

			dev_err(dev, "Failed to enable regulator %i (ret=%i)\n",

				i, ret);

			goto err;

		}

	}



	return 0;



err:

	rcar_gyroadc_deinit_supplies(indio_dev);

	return ret;

}



static int rcar_gyroadc_probe(struct platform_device *pdev)

{

	const struct of_device_id *of_id =

		of_match_device(rcar_gyroadc_match, &pdev->dev);

	struct device *dev = &pdev->dev;

	struct rcar_gyroadc *priv;

	struct iio_dev *indio_dev;

	struct resource *mem;

	int ret;



	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));

	if (!indio_dev) {

		dev_err(dev, "Failed to allocate IIO device.\n");

		return -ENOMEM;

	}



	priv = iio_priv(indio_dev);

	priv->dev = dev;



	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	priv->regs = devm_ioremap_resource(dev, mem);

	if (IS_ERR(priv->regs))

		return PTR_ERR(priv->regs);



	priv->iclk = devm_clk_get(dev, "if");

	if (IS_ERR(priv->iclk)) {

		ret = PTR_ERR(priv->iclk);

		if (ret != -EPROBE_DEFER)

			dev_err(dev, "Failed to get IF clock (ret=%i)\n", ret);

		return ret;

	}



	ret = rcar_gyroadc_parse_subdevs(indio_dev);

	if (ret)

		return ret;



	ret = rcar_gyroadc_init_supplies(indio_dev);

	if (ret)

		return ret;



	priv->model = (enum rcar_gyroadc_model)of_id->data;



	platform_set_drvdata(pdev, indio_dev);



	indio_dev->name = DRIVER_NAME;

	indio_dev->dev.parent = dev;

	indio_dev->dev.of_node = pdev->dev.of_node;

	indio_dev->info = &rcar_gyroadc_iio_info;

	indio_dev->modes = INDIO_DIRECT_MODE;



	ret = clk_prepare_enable(priv->iclk);

	if (ret) {

		dev_err(dev, "Could not prepare or enable the IF clock.\n");

		goto err_clk_if_enable;

	}



	pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS);

	pm_runtime_use_autosuspend(dev);

	pm_runtime_enable(dev);



	pm_runtime_get_sync(dev);

	rcar_gyroadc_hw_init(priv);

	rcar_gyroadc_hw_start(priv);



	ret = iio_device_register(indio_dev);

	if (ret) {

		dev_err(dev, "Couldn't register IIO device.\n");

		goto err_iio_device_register;

	}



	pm_runtime_put_sync(dev);



	return 0;



err_iio_device_register:

	rcar_gyroadc_hw_stop(priv);

	pm_runtime_put_sync(dev);

	pm_runtime_disable(dev);

	pm_runtime_set_suspended(dev);

	clk_disable_unprepare(priv->iclk);

err_clk_if_enable:

	rcar_gyroadc_deinit_supplies(indio_dev);



	return ret;

}



static int rcar_gyroadc_remove(struct platform_device *pdev)

{

	struct iio_dev *indio_dev = platform_get_drvdata(pdev);

	struct rcar_gyroadc *priv = iio_priv(indio_dev);

	struct device *dev = priv->dev;



	iio_device_unregister(indio_dev);

	pm_runtime_get_sync(dev);

	rcar_gyroadc_hw_stop(priv);

	pm_runtime_put_sync(dev);

	pm_runtime_disable(dev);

	pm_runtime_set_suspended(dev);

	clk_disable_unprepare(priv->iclk);

	rcar_gyroadc_deinit_supplies(indio_dev);



	return 0;

}



#if defined(CONFIG_PM)

static int rcar_gyroadc_suspend(struct device *dev)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct rcar_gyroadc *priv = iio_priv(indio_dev);



	rcar_gyroadc_hw_stop(priv);



	return 0;

}



static int rcar_gyroadc_resume(struct device *dev)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct rcar_gyroadc *priv = iio_priv(indio_dev);



	rcar_gyroadc_hw_start(priv);



	return 0;

}

#endif



static const struct dev_pm_ops rcar_gyroadc_pm_ops = {

	SET_RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL)

};



static struct platform_driver rcar_gyroadc_driver = {

	.probe          = rcar_gyroadc_probe,

	.remove         = rcar_gyroadc_remove,

	.driver         = {

		.name		= DRIVER_NAME,

		.of_match_table	= rcar_gyroadc_match,

		.pm		= &rcar_gyroadc_pm_ops,

	},

};



module_platform_driver(rcar_gyroadc_driver);



MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");

MODULE_DESCRIPTION("Renesas R-Car GyroADC driver");

MODULE_LICENSE("GPL");

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