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Message-Id: <20220111134118.3423422-1-o.rempel@pengutronix.de>
Date: Tue, 11 Jan 2022 14:41:18 +0100
From: Oleksij Rempel <o.rempel@...gutronix.de>
To: Jonathan Cameron <jic23@...nel.org>
Cc: Oleksij Rempel <o.rempel@...gutronix.de>,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Pengutronix Kernel Team <kernel@...gutronix.de>,
David Jander <david@...tonic.nl>,
Robin van der Gracht <robin@...tonic.nl>,
linux-iio@...r.kernel.org, Lars-Peter Clausen <lars@...afoo.de>
Subject: [PATCH v2 1/1] iio: adc: tsc2046: add .read_raw support
Add read_raw() support to make use of iio_hwmon and other iio clients.
Signed-off-by: Oleksij Rempel <o.rempel@...gutronix.de>
---
drivers/iio/adc/ti-tsc2046.c | 115 ++++++++++++++++++++++++++++-------
1 file changed, 94 insertions(+), 21 deletions(-)
diff --git a/drivers/iio/adc/ti-tsc2046.c b/drivers/iio/adc/ti-tsc2046.c
index c373da11bff1..59ab6622d6a2 100644
--- a/drivers/iio/adc/ti-tsc2046.c
+++ b/drivers/iio/adc/ti-tsc2046.c
@@ -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 +266,47 @@ 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;
+ }
+
+ 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 +317,25 @@ 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 +442,37 @@ 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 +503,7 @@ 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,
};
@@ -562,16 +645,6 @@ 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
--
2.30.2
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