| Message ID | 20220111134118.3423422-1-o.rempel@pengutronix.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v2,1/1] iio: adc: tsc2046: add .read_raw support | expand |
On Tue, 11 Jan 2022 14:41:18 +0100 Oleksij Rempel <o.rempel@pengutronix.de> wrote: > Add read_raw() support to make use of iio_hwmon and other iio clients. > > Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Hi Oleksij, Busy week so I only just replied to the v1 discussion. The carry over to this is I think you need to set a maximum for settling time in the driver to avoid ending up with really large allocations if someone uses a crazy dts. Otherwise looks good to me. Thanks, Jonathan > --- > 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
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
Add read_raw() support to make use of iio_hwmon and other iio clients. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- drivers/iio/adc/ti-tsc2046.c | 115 ++++++++++++++++++++++++++++------- 1 file changed, 94 insertions(+), 21 deletions(-)