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Commit 8ba99f7f authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Greg Kroah-Hartman
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iio: adc: stx104: Implement and utilize register structures 



[ Upstream commit 6cfd14c54b1f42f29097244c1b6208f8268d7d5b ]

Reduce magic numbers and improve code readability by implementing and
utilizing named register data structures.

Tested-by: default avatarFred Eckert <Frede@cmslaser.com>
Signed-off-by: default avatarWilliam Breathitt Gray <william.gray@linaro.org>
Link: https://lore.kernel.org/r/8cb91d5b53e57b066120e42ea07000d6c7ef5543.1657213745.git.william.gray@linaro.org


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Stable-dep-of: 4f9b80aefb9e ("iio: addac: stx104: Fix race condition when converting analog-to-digital")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 4edf338a

drivers/iio/adc/stx104.c

+50 −24
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/spinlock.h>

#include <linux/types.h>



#define STX104_OUT_CHAN(chan) {				\

	.type = IIO_VOLTAGE,				\
@@ -44,14 +45,36 @@ static unsigned int num_stx104; 
module_param_hw_array(base, uint, ioport, &num_stx104, 0);

MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses");



/**

 * struct stx104_reg - device register structure

 * @ssr_ad:	Software Strobe Register and ADC Data

 * @achan:	ADC Channel

 * @dio:	Digital I/O

 * @dac:	DAC Channels

 * @cir_asr:	Clear Interrupts and ADC Status

 * @acr:	ADC Control

 * @pccr_fsh:	Pacer Clock Control and FIFO Status MSB

 * @acfg:	ADC Configuration

 */

struct stx104_reg {

	u16 ssr_ad;

	u8 achan;

	u8 dio;

	u16 dac[2];

	u8 cir_asr;

	u8 acr;

	u8 pccr_fsh;

	u8 acfg;

};



/**

 * struct stx104_iio - IIO device private data structure

 * @chan_out_states:	channels' output states

 * @base:		base port address of the IIO device

 * @reg:		I/O address offset for the device registers

 */

struct stx104_iio {

	unsigned int chan_out_states[STX104_NUM_OUT_CHAN];

	void __iomem *base;

	struct stx104_reg __iomem *reg;

};



/**
@@ -64,7 +87,7 @@ struct stx104_iio { 
struct stx104_gpio {

	struct gpio_chip chip;

	spinlock_t lock;

	void __iomem *base;

	u8 __iomem *base;

	unsigned int out_state;

};
@@ -72,6 +95,7 @@ static int stx104_read_raw(struct iio_dev *indio_dev, 
	struct iio_chan_spec const *chan, int *val, int *val2, long mask)

{

	struct stx104_iio *const priv = iio_priv(indio_dev);

	struct stx104_reg __iomem *const reg = priv->reg;

	unsigned int adc_config;

	int adbu;

	int gain;
@@ -79,7 +103,7 @@ static int stx104_read_raw(struct iio_dev *indio_dev, 
	switch (mask) {

	case IIO_CHAN_INFO_HARDWAREGAIN:

		/* get gain configuration */

		adc_config = ioread8(priv->base + 11);

		adc_config = ioread8(&reg->acfg);

		gain = adc_config & 0x3;



		*val = 1 << gain;
@@ -91,24 +115,26 @@ static int stx104_read_raw(struct iio_dev *indio_dev, 
		}



		/* select ADC channel */

		iowrite8(chan->channel | (chan->channel << 4), priv->base + 2);

		iowrite8(chan->channel | (chan->channel << 4), &reg->achan);



		/* trigger ADC sample capture and wait for completion */

		iowrite8(0, priv->base);

		while (ioread8(priv->base + 8) & BIT(7));

		/* trigger ADC sample capture by writing to the 8-bit

		 * Software Strobe Register and wait for completion

		 */

		iowrite8(0, &reg->ssr_ad);

		while (ioread8(&reg->cir_asr) & BIT(7));



		*val = ioread16(priv->base);

		*val = ioread16(&reg->ssr_ad);

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_OFFSET:

		/* get ADC bipolar/unipolar configuration */

		adc_config = ioread8(priv->base + 11);

		adc_config = ioread8(&reg->acfg);

		adbu = !(adc_config & BIT(2));



		*val = -32768 * adbu;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		/* get ADC bipolar/unipolar and gain configuration */

		adc_config = ioread8(priv->base + 11);

		adc_config = ioread8(&reg->acfg);

		adbu = !(adc_config & BIT(2));

		gain = adc_config & 0x3;
@@ -130,16 +156,16 @@ static int stx104_write_raw(struct iio_dev *indio_dev, 
		/* Only four gain states (x1, x2, x4, x8) */

		switch (val) {

		case 1:

			iowrite8(0, priv->base + 11);

			iowrite8(0, &priv->reg->acfg);

			break;

		case 2:

			iowrite8(1, priv->base + 11);

			iowrite8(1, &priv->reg->acfg);

			break;

		case 4:

			iowrite8(2, priv->base + 11);

			iowrite8(2, &priv->reg->acfg);

			break;

		case 8:

			iowrite8(3, priv->base + 11);

			iowrite8(3, &priv->reg->acfg);

			break;

		default:

			return -EINVAL;
@@ -153,7 +179,7 @@ static int stx104_write_raw(struct iio_dev *indio_dev, 
				return -EINVAL;



			priv->chan_out_states[chan->channel] = val;

			iowrite16(val, priv->base + 4 + 2 * chan->channel);

			iowrite16(val, &priv->reg->dac[chan->channel]);



			return 0;

		}
@@ -307,15 +333,15 @@ static int stx104_probe(struct device *dev, unsigned int id) 
	}



	priv = iio_priv(indio_dev);

	priv->base = devm_ioport_map(dev, base[id], STX104_EXTENT);

	if (!priv->base)

	priv->reg = devm_ioport_map(dev, base[id], STX104_EXTENT);

	if (!priv->reg)

		return -ENOMEM;



	indio_dev->info = &stx104_info;

	indio_dev->modes = INDIO_DIRECT_MODE;



	/* determine if differential inputs */

	if (ioread8(priv->base + 8) & BIT(5)) {

	if (ioread8(&priv->reg->cir_asr) & BIT(5)) {

		indio_dev->num_channels = ARRAY_SIZE(stx104_channels_diff);

		indio_dev->channels = stx104_channels_diff;

	} else {
@@ -327,14 +353,14 @@ static int stx104_probe(struct device *dev, unsigned int id) 
	indio_dev->dev.parent = dev;



	/* configure device for software trigger operation */

	iowrite8(0, priv->base + 9);

	iowrite8(0, &priv->reg->acr);



	/* initialize gain setting to x1 */

	iowrite8(0, priv->base + 11);

	iowrite8(0, &priv->reg->acfg);



	/* initialize DAC output to 0V */

	iowrite16(0, priv->base + 4);

	iowrite16(0, priv->base + 6);

	iowrite16(0, &priv->reg->dac[0]);

	iowrite16(0, &priv->reg->dac[1]);



	stx104gpio->chip.label = dev_name(dev);

	stx104gpio->chip.parent = dev;
@@ -349,7 +375,7 @@ static int stx104_probe(struct device *dev, unsigned int id) 
	stx104gpio->chip.get_multiple = stx104_gpio_get_multiple;

	stx104gpio->chip.set = stx104_gpio_set;

	stx104gpio->chip.set_multiple = stx104_gpio_set_multiple;

	stx104gpio->base = priv->base + 3;

	stx104gpio->base = &priv->reg->dio;

	stx104gpio->out_state = 0x0;



	spin_lock_init(&stx104gpio->lock);