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Commit 0010d6b4 authored by Sanchayan Maity's avatar Sanchayan Maity Committed by Jonathan Cameron
Browse files

iio: adc: vf610: Add IIO buffer support for Vybrid ADC 



This patch adds support for IIO buffer to the Vybrid ADC driver.
IIO triggered buffer infrastructure along with iio sysfs trigger
is used to leverage continuous sampling support provided by the
ADC block.

Signed-off-by: default avatarSanchayan Maity <maitysanchayan@gmail.com>
Acked-by: default avatarFugang Duan <B38611@freescale.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent f6707ef7

drivers/iio/adc/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -361,6 +361,8 @@ config TWL6030_GPADC 
config VF610_ADC

	tristate "Freescale vf610 ADC driver"

	depends on OF

	select IIO_BUFFER

	select IIO_TRIGGERED_BUFFER

	help

	  Say yes here to support for Vybrid board analog-to-digital converter.

	  Since the IP is used for i.MX6SLX, the driver also support i.MX6SLX.

drivers/iio/adc/vf610_adc.c

+98 −7
Original line number Diff line number Diff line
@@ -34,8 +34,11 @@ 
#include <linux/err.h>



#include <linux/iio/iio.h>

#include <linux/iio/buffer.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/driver.h>

#include <linux/iio/trigger.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/triggered_buffer.h>



/* This will be the driver name the kernel reports */

#define DRIVER_NAME "vf610-adc"
@@ -170,6 +173,7 @@ struct vf610_adc { 
	u32 sample_freq_avail[5];



	struct completion completion;

	u16 buffer[8];

};



static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 };
@@ -505,12 +509,24 @@ static const struct iio_chan_spec_ext_info vf610_ext_info[] = { 
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\

				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\

	.ext_info = vf610_ext_info,				\

	.scan_index = (_idx),			\

	.scan_type = {					\

		.sign = 'u',				\

		.realbits = 12,				\

		.storagebits = 16,			\

	},						\

}



#define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) {	\

	.type = (_chan_type),	\

	.channel = (_idx),		\

	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),	\

	.scan_index = (_idx),					\

	.scan_type = {						\

		.sign = 'u',					\

		.realbits = 12,					\

		.storagebits = 16,				\

	},							\

}



static const struct iio_chan_spec vf610_adc_iio_channels[] = {
@@ -531,6 +547,7 @@ static const struct iio_chan_spec vf610_adc_iio_channels[] = { 
	VF610_ADC_CHAN(14, IIO_VOLTAGE),

	VF610_ADC_CHAN(15, IIO_VOLTAGE),

	VF610_ADC_TEMPERATURE_CHAN(26, IIO_TEMP),

	IIO_CHAN_SOFT_TIMESTAMP(32),

	/* sentinel */

};
@@ -559,12 +576,19 @@ static int vf610_adc_read_data(struct vf610_adc *info) 


static irqreturn_t vf610_adc_isr(int irq, void *dev_id)

{

	struct vf610_adc *info = (struct vf610_adc *)dev_id;

	struct iio_dev *indio_dev = (struct iio_dev *)dev_id;

	struct vf610_adc *info = iio_priv(indio_dev);

	int coco;



	coco = readl(info->regs + VF610_REG_ADC_HS);

	if (coco & VF610_ADC_HS_COCO0) {

		info->value = vf610_adc_read_data(info);

		if (iio_buffer_enabled(indio_dev)) {

			info->buffer[0] = info->value;

			iio_push_to_buffers_with_timestamp(indio_dev,

					info->buffer, iio_get_time_ns());

			iio_trigger_notify_done(indio_dev->trig);

		} else

			complete(&info->completion);

	}
@@ -613,8 +637,12 @@ static int vf610_read_raw(struct iio_dev *indio_dev, 
	case IIO_CHAN_INFO_RAW:

	case IIO_CHAN_INFO_PROCESSED:

		mutex_lock(&indio_dev->mlock);

		reinit_completion(&info->completion);

		if (iio_buffer_enabled(indio_dev)) {

			mutex_unlock(&indio_dev->mlock);

			return -EBUSY;

		}



		reinit_completion(&info->completion);

		hc_cfg = VF610_ADC_ADCHC(chan->channel);

		hc_cfg |= VF610_ADC_AIEN;

		writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
@@ -694,6 +722,60 @@ static int vf610_write_raw(struct iio_dev *indio_dev, 
	return -EINVAL;

}



static int vf610_adc_buffer_postenable(struct iio_dev *indio_dev)

{

	struct vf610_adc *info = iio_priv(indio_dev);

	unsigned int channel;

	int ret;

	int val;



	ret = iio_triggered_buffer_postenable(indio_dev);

	if (ret)

		return ret;



	val = readl(info->regs + VF610_REG_ADC_GC);

	val |= VF610_ADC_ADCON;

	writel(val, info->regs + VF610_REG_ADC_GC);



	channel = find_first_bit(indio_dev->active_scan_mask,

						indio_dev->masklength);



	val = VF610_ADC_ADCHC(channel);

	val |= VF610_ADC_AIEN;



	writel(val, info->regs + VF610_REG_ADC_HC0);



	return 0;

}



static int vf610_adc_buffer_predisable(struct iio_dev *indio_dev)

{

	struct vf610_adc *info = iio_priv(indio_dev);

	unsigned int hc_cfg = 0;

	int val, ret;



	val = readl(info->regs + VF610_REG_ADC_GC);

	val &= ~VF610_ADC_ADCON;

	writel(val, info->regs + VF610_REG_ADC_GC);



	hc_cfg |= VF610_ADC_CONV_DISABLE;

	hc_cfg &= ~VF610_ADC_AIEN;



	writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);



	ret = iio_triggered_buffer_predisable(indio_dev);

	if (ret)

		return ret;



	return 0;

}



static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {

	.postenable = &vf610_adc_buffer_postenable,

	.predisable = &vf610_adc_buffer_predisable,

	.validate_scan_mask = &iio_validate_scan_mask_onehot,

};



static int vf610_adc_reg_access(struct iio_dev *indio_dev,

			unsigned reg, unsigned writeval,

			unsigned *readval)
@@ -753,7 +835,7 @@ static int vf610_adc_probe(struct platform_device *pdev) 


	ret = devm_request_irq(info->dev, irq,

				vf610_adc_isr, 0,

				dev_name(&pdev->dev), info);

				dev_name(&pdev->dev), indio_dev);

	if (ret < 0) {

		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);

		return ret;
@@ -806,15 +888,23 @@ static int vf610_adc_probe(struct platform_device *pdev) 
	vf610_adc_cfg_init(info);

	vf610_adc_hw_init(info);



	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,

					NULL, &iio_triggered_buffer_setup_ops);

	if (ret < 0) {

		dev_err(&pdev->dev, "Couldn't initialise the buffer\n");

		goto error_iio_device_register;

	}



	ret = iio_device_register(indio_dev);

	if (ret) {

		dev_err(&pdev->dev, "Couldn't register the device.\n");

		goto error_iio_device_register;

		goto error_adc_buffer_init;

	}



	return 0;





error_adc_buffer_init:

	iio_triggered_buffer_cleanup(indio_dev);

error_iio_device_register:

	clk_disable_unprepare(info->clk);

error_adc_clk_enable:
@@ -829,6 +919,7 @@ static int vf610_adc_remove(struct platform_device *pdev) 
	struct vf610_adc *info = iio_priv(indio_dev);



	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	regulator_disable(info->vref);

	clk_disable_unprepare(info->clk);