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iio: adc: tsc2046: add .read_raw support

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

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20220117082852.3370869-1-o.rempel@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Oleksij Rempel 2022-01-17 09:28:51 +01:00 committed by Jonathan Cameron
parent 2d255ec510
commit b617693a5d
1 changed files with 97 additions and 21 deletions
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118
drivers/iio/adc/ti-tsc2046.c
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@ -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