Commit b617693a authored by Oleksij Rempel's avatar Oleksij Rempel Committed by Jonathan Cameron
Browse files

iio: adc: tsc2046: add .read_raw support 



Add read_raw() support to make use of iio_hwmon and other iio clients.

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20220117082852.3370869-1-o.rempel@pengutronix.de


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 2d255ec5

drivers/iio/adc/ti-tsc2046.c

+97 −21
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ 
#define TI_TSC2046_EXT_POLL_CNT			3

#define TI_TSC2046_POLL_CNT \

	(TI_TSC2046_MIN_POLL_CNT + TI_TSC2046_EXT_POLL_CNT)

#define TI_TSC2046_INT_VREF			2500



/* Represents a HW sample */

struct tsc2046_adc_atom {
@@ -166,9 +167,6 @@ struct tsc2046_adc_priv { 
	struct tsc2046_adc_atom *rx;

	struct tsc2046_adc_atom *tx;



	struct tsc2046_adc_atom *rx_one;

	struct tsc2046_adc_atom *tx_one;



	unsigned int count;

	unsigned int groups;

	u32 effective_speed_hz;
@@ -184,6 +182,8 @@ struct tsc2046_adc_priv { 
	.type = IIO_VOLTAGE,					\

	.indexed = 1,						\

	.channel = index,					\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\

	.datasheet_name = "#name",				\

	.scan_index = index,					\

	.scan_type = {						\
@@ -247,6 +247,14 @@ static u8 tsc2046_adc_get_cmd(struct tsc2046_adc_priv *priv, int ch_idx, 
	else

		pd = 0;



	switch (ch_idx) {

	case TI_TSC2046_ADDR_TEMP1:

	case TI_TSC2046_ADDR_AUX:

	case TI_TSC2046_ADDR_VBAT:

	case TI_TSC2046_ADDR_TEMP0:

		pd |= TI_TSC2046_SER | TI_TSC2046_PD1_VREF_ON;

	}



	return TI_TSC2046_START | FIELD_PREP(TI_TSC2046_ADDR, ch_idx) | pd;

}
@@ -258,16 +266,50 @@ static u16 tsc2046_adc_get_value(struct tsc2046_adc_atom *buf) 
static int tsc2046_adc_read_one(struct tsc2046_adc_priv *priv, int ch_idx,

				u32 *effective_speed_hz)

{

	struct tsc2046_adc_ch_cfg *ch = &priv->ch_cfg[ch_idx];

	struct tsc2046_adc_atom *rx_buf, *tx_buf;

	unsigned int val, val_normalized = 0;

	int ret, i, count_skip = 0, max_count;

	struct spi_transfer xfer;

	struct spi_message msg;

	int ret;

	u8 cmd;



	if (!effective_speed_hz) {

		count_skip = tsc2046_adc_time_to_count(priv, ch->settling_time_us);

		max_count = count_skip + ch->oversampling_ratio;

	} else {

		max_count = 1;

	}



	if (sizeof(*tx_buf) * max_count > PAGE_SIZE)

		return -ENOSPC;



	tx_buf = kcalloc(max_count, sizeof(*tx_buf), GFP_KERNEL);

	if (!tx_buf)

		return -ENOMEM;



	rx_buf = kcalloc(max_count, sizeof(*rx_buf), GFP_KERNEL);

	if (!rx_buf) {

		ret = -ENOMEM;

		goto free_tx;

	}



	/*

	 * Do not enable automatic power down on working samples. Otherwise the

	 * plates will never be completely charged.

	 */

	cmd = tsc2046_adc_get_cmd(priv, ch_idx, true);



	for (i = 0; i < max_count - 1; i++)

		tx_buf[i].cmd = cmd;



	/* automatically power down on last sample */

	tx_buf[i].cmd = tsc2046_adc_get_cmd(priv, ch_idx, false);



	memset(&xfer, 0, sizeof(xfer));

	priv->tx_one->cmd = tsc2046_adc_get_cmd(priv, ch_idx, false);

	priv->tx_one->data = 0;

	xfer.tx_buf = priv->tx_one;

	xfer.rx_buf = priv->rx_one;

	xfer.len = sizeof(*priv->tx_one);

	xfer.tx_buf = tx_buf;

	xfer.rx_buf = rx_buf;

	xfer.len = sizeof(*tx_buf) * max_count;

	spi_message_init_with_transfers(&msg, &xfer, 1);



	/*
@@ -278,13 +320,25 @@ static int tsc2046_adc_read_one(struct tsc2046_adc_priv *priv, int ch_idx, 
	if (ret) {

		dev_err_ratelimited(&priv->spi->dev, "SPI transfer failed %pe\n",

				    ERR_PTR(ret));

		return ret;

		goto free_bufs;

	}



	if (effective_speed_hz)

		*effective_speed_hz = xfer.effective_speed_hz;



	return tsc2046_adc_get_value(priv->rx_one);

	for (i = 0; i < max_count - count_skip; i++) {

		val = tsc2046_adc_get_value(&rx_buf[count_skip + i]);

		val_normalized += val;

	}



	ret = DIV_ROUND_UP(val_normalized, max_count - count_skip);



free_bufs:

	kfree(rx_buf);

free_tx:

	kfree(tx_buf);



	return ret;

}



static size_t tsc2046_adc_group_set_layout(struct tsc2046_adc_priv *priv,
@@ -391,6 +445,37 @@ static irqreturn_t tsc2046_adc_trigger_handler(int irq, void *p) 
	return IRQ_HANDLED;

}



static int tsc2046_adc_read_raw(struct iio_dev *indio_dev,

				struct iio_chan_spec const *chan,

				int *val, int *val2, long m)

{

	struct tsc2046_adc_priv *priv = iio_priv(indio_dev);

	int ret;



	switch (m) {

	case IIO_CHAN_INFO_RAW:

		ret = tsc2046_adc_read_one(priv, chan->channel, NULL);

		if (ret < 0)

			return ret;



		*val = ret;



		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		/*

		 * Note: the TSC2046 has internal voltage divider on the VBAT

		 * line. This divider can be influenced by external divider.

		 * So, it is better to use external voltage-divider driver

		 * instead, which is calculating complete chain.

		 */

		*val = TI_TSC2046_INT_VREF;

		*val2 = chan->scan_type.realbits;

		return IIO_VAL_FRACTIONAL_LOG2;

	}



	return -EINVAL;

}



static int tsc2046_adc_update_scan_mode(struct iio_dev *indio_dev,

					const unsigned long *active_scan_mask)

{
@@ -421,6 +506,7 @@ static int tsc2046_adc_update_scan_mode(struct iio_dev *indio_dev, 
}



static const struct iio_info tsc2046_adc_info = {

	.read_raw	  = tsc2046_adc_read_raw,

	.update_scan_mode = tsc2046_adc_update_scan_mode,

};
@@ -563,16 +649,6 @@ static int tsc2046_adc_setup_spi_msg(struct tsc2046_adc_priv *priv) 
	size_t size;

	int ret;



	priv->tx_one = devm_kzalloc(&priv->spi->dev, sizeof(*priv->tx_one),

				    GFP_KERNEL);

	if (!priv->tx_one)

		return -ENOMEM;



	priv->rx_one = devm_kzalloc(&priv->spi->dev, sizeof(*priv->rx_one),

				    GFP_KERNEL);

	if (!priv->rx_one)

		return -ENOMEM;



	/*

	 * Make dummy read to set initial power state and get real SPI clock

	 * freq. It seems to be not important which channel is used for this