[PATCH v2] iio: accel: sca3000: remove duplicated code in sca3000_read_data()

Andrew Ijano posted 1 patch 9 months, 2 weeks ago
drivers/iio/accel/sca3000.c | 82 ++++++++++++++-----------------------
1 file changed, 30 insertions(+), 52 deletions(-)
[PATCH v2] iio: accel: sca3000: remove duplicated code in sca3000_read_data()
Posted by Andrew Ijano 9 months, 2 weeks ago
Remove duplicated code between sca3000_read_data() and
sca3000_read_data_short() functions.

The common behavior is centralized in just one sca3000_read_data()
function and used for every case.

Signed-off-by: Andrew Ijano <andrew.lopes@alumni.usp.br>
Co-developed-by: Gustavo Bastos <gustavobastos@usp.br>
Signed-off-by: Gustavo Bastos <gustavobastos@usp.br>
---
 drivers/iio/accel/sca3000.c | 82 ++++++++++++++-----------------------
 1 file changed, 30 insertions(+), 52 deletions(-)

diff --git a/drivers/iio/accel/sca3000.c b/drivers/iio/accel/sca3000.c
index aabe4491efd7..c4b1da7f8de1 100644
--- a/drivers/iio/accel/sca3000.c
+++ b/drivers/iio/accel/sca3000.c
@@ -281,10 +281,11 @@ static int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val)
 	return spi_write(st->us, st->tx, 2);
 }
 
-static int sca3000_read_data_short(struct sca3000_state *st,
-				   u8 reg_address_high,
-				   int len)
+static int sca3000_read_data(struct sca3000_state *st,
+			     u8 reg_address_high,
+			     int len)
 {
+	int ret;
 	struct spi_transfer xfer[2] = {
 		{
 			.len = 1,
@@ -296,7 +297,10 @@ static int sca3000_read_data_short(struct sca3000_state *st,
 	};
 	st->tx[0] = SCA3000_READ_REG(reg_address_high);
 
-	return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
+	ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
+	if (ret)
+		dev_err(&st->us->dev, "problem reading register\n");
+	return ret;
 }
 
 /**
@@ -309,7 +313,7 @@ static int sca3000_reg_lock_on(struct sca3000_state *st)
 {
 	int ret;
 
-	ret = sca3000_read_data_short(st, SCA3000_REG_STATUS_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_STATUS_ADDR, 1);
 	if (ret < 0)
 		return ret;
 
@@ -412,7 +416,7 @@ static int sca3000_read_ctrl_reg(struct sca3000_state *st,
 	ret = sca3000_write_reg(st, SCA3000_REG_CTRL_SEL_ADDR, ctrl_reg);
 	if (ret)
 		goto error_ret;
-	ret = sca3000_read_data_short(st, SCA3000_REG_CTRL_DATA_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_CTRL_DATA_ADDR, 1);
 	if (ret)
 		goto error_ret;
 	return st->rx[0];
@@ -432,7 +436,7 @@ static int sca3000_print_rev(struct iio_dev *indio_dev)
 	struct sca3000_state *st = iio_priv(indio_dev);
 
 	mutex_lock(&st->lock);
-	ret = sca3000_read_data_short(st, SCA3000_REG_REVID_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_REVID_ADDR, 1);
 	if (ret < 0)
 		goto error_ret;
 	dev_info(&indio_dev->dev,
@@ -575,7 +579,7 @@ static inline int __sca3000_get_base_freq(struct sca3000_state *st,
 {
 	int ret;
 
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		goto error_ret;
 	switch (SCA3000_REG_MODE_MODE_MASK & st->rx[0]) {
@@ -665,7 +669,7 @@ static int sca3000_read_3db_freq(struct sca3000_state *st, int *val)
 {
 	int ret;
 
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		return ret;
 
@@ -703,7 +707,7 @@ static int sca3000_write_3db_freq(struct sca3000_state *st, int val)
 		mode = SCA3000_REG_MODE_MEAS_MODE_OP_2;
 	else
 		return -EINVAL;
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		return ret;
 
@@ -732,7 +736,7 @@ static int sca3000_read_raw(struct iio_dev *indio_dev,
 				return -EBUSY;
 			}
 			address = sca3000_addresses[chan->address][0];
-			ret = sca3000_read_data_short(st, address, 2);
+			ret = sca3000_read_data(st, address, 2);
 			if (ret < 0) {
 				mutex_unlock(&st->lock);
 				return ret;
@@ -742,7 +746,7 @@ static int sca3000_read_raw(struct iio_dev *indio_dev,
 					     chan->scan_type.realbits - 1);
 		} else {
 			/* get the temperature when available */
-			ret = sca3000_read_data_short(st,
+			ret = sca3000_read_data(st,
 						      SCA3000_REG_TEMP_MSB_ADDR,
 						      2);
 			if (ret < 0) {
@@ -830,7 +834,7 @@ static ssize_t sca3000_read_av_freq(struct device *dev,
 	int len = 0, ret, val;
 
 	mutex_lock(&st->lock);
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	val = st->rx[0];
 	mutex_unlock(&st->lock);
 	if (ret)
@@ -969,32 +973,6 @@ static const struct attribute_group sca3000_attribute_group = {
 	.attrs = sca3000_attributes,
 };
 
-static int sca3000_read_data(struct sca3000_state *st,
-			     u8 reg_address_high,
-			     u8 *rx,
-			     int len)
-{
-	int ret;
-	struct spi_transfer xfer[2] = {
-		{
-			.len = 1,
-			.tx_buf = st->tx,
-		}, {
-			.len = len,
-			.rx_buf = rx,
-		}
-	};
-
-	st->tx[0] = SCA3000_READ_REG(reg_address_high);
-	ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
-	if (ret) {
-		dev_err(&st->us->dev, "problem reading register\n");
-		return ret;
-	}
-
-	return 0;
-}
-
 /**
  * sca3000_ring_int_process() - ring specific interrupt handling.
  * @val: Value of the interrupt status register.
@@ -1008,7 +986,7 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
 	mutex_lock(&st->lock);
 
 	if (val & SCA3000_REG_INT_STATUS_HALF) {
-		ret = sca3000_read_data_short(st, SCA3000_REG_BUF_COUNT_ADDR,
+		ret = sca3000_read_data(st, SCA3000_REG_BUF_COUNT_ADDR,
 					      1);
 		if (ret)
 			goto error_ret;
@@ -1017,7 +995,7 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
 		 * num_available is the total number of samples available
 		 * i.e. number of time points * number of channels.
 		 */
-		ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR, st->rx,
+		ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR,
 					num_available * 2);
 		if (ret)
 			goto error_ret;
@@ -1060,7 +1038,7 @@ static irqreturn_t sca3000_event_handler(int irq, void *private)
 	 * but ensures no interrupt is missed.
 	 */
 	mutex_lock(&st->lock);
-	ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_INT_STATUS_ADDR, 1);
 	val = st->rx[0];
 	mutex_unlock(&st->lock);
 	if (ret)
@@ -1121,7 +1099,7 @@ static int sca3000_read_event_config(struct iio_dev *indio_dev,
 	/* read current value of mode register */
 	mutex_lock(&st->lock);
 
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		goto error_ret;
 
@@ -1164,7 +1142,7 @@ static int sca3000_freefall_set_state(struct iio_dev *indio_dev, bool state)
 	int ret;
 
 	/* read current value of mode register */
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		return ret;
 
@@ -1214,7 +1192,7 @@ static int sca3000_motion_detect_set_state(struct iio_dev *indio_dev, int axis,
 	}
 
 	/* read current value of mode register */
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		return ret;
 	/* if off and should be on */
@@ -1287,7 +1265,7 @@ int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state)
 	int ret;
 
 	mutex_lock(&st->lock);
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		goto error_ret;
 	if (state) {
@@ -1322,7 +1300,7 @@ static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev)
 	mutex_lock(&st->lock);
 
 	/* Enable the 50% full interrupt */
-	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_INT_MASK_ADDR, 1);
 	if (ret)
 		goto error_unlock;
 	ret = sca3000_write_reg(st,
@@ -1353,7 +1331,7 @@ static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)
 	/* Disable the 50% full interrupt */
 	mutex_lock(&st->lock);
 
-	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_INT_MASK_ADDR, 1);
 	if (ret)
 		goto unlock;
 	ret = sca3000_write_reg(st,
@@ -1383,7 +1361,7 @@ static int sca3000_clean_setup(struct sca3000_state *st)
 
 	mutex_lock(&st->lock);
 	/* Ensure all interrupts have been acknowledged */
-	ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_INT_STATUS_ADDR, 1);
 	if (ret)
 		goto error_ret;
 
@@ -1409,7 +1387,7 @@ static int sca3000_clean_setup(struct sca3000_state *st)
 	if (ret)
 		goto error_ret;
 	/* Enable interrupts, relevant to mode and set up as active low */
-	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_INT_MASK_ADDR, 1);
 	if (ret)
 		goto error_ret;
 	ret = sca3000_write_reg(st,
@@ -1423,7 +1401,7 @@ static int sca3000_clean_setup(struct sca3000_state *st)
 	 * Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5
 	 * as that occurs in one of the example on the datasheet
 	 */
-	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
 	if (ret)
 		goto error_ret;
 	ret = sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,
@@ -1510,7 +1488,7 @@ static int sca3000_stop_all_interrupts(struct sca3000_state *st)
 	int ret;
 
 	mutex_lock(&st->lock);
-	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
+	ret = sca3000_read_data(st, SCA3000_REG_INT_MASK_ADDR, 1);
 	if (ret)
 		goto error_ret;
 	ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR,
-- 
2.49.0
Re: [PATCH v2] iio: accel: sca3000: remove duplicated code in sca3000_read_data()
Posted by Jonathan Cameron 9 months, 2 weeks ago
On Fri, 25 Apr 2025 20:50:51 -0300
Andrew Ijano <andrew.ijano@gmail.com> wrote:

> Remove duplicated code between sca3000_read_data() and
> sca3000_read_data_short() functions.
> 
> The common behavior is centralized in just one sca3000_read_data()
> function and used for every case.
> 
> Signed-off-by: Andrew Ijano <andrew.lopes@alumni.usp.br>
> Co-developed-by: Gustavo Bastos <gustavobastos@usp.br>
> Signed-off-by: Gustavo Bastos <gustavobastos@usp.br>

Look at the helpers that exist for spi sequences like this.
This is an old driver so may not be making full use of newer infrastructure.

In particular a lot of these can probably become spi_w8r8()and
it may make sense to move the SCA3000_READ_REG() to the callers to avoid the
need for these helpers at all.

Note that is not an appropriate change for the large reads though as
spi_write_then_read() bounces all buffers and so would add a copy
to those high(ish) performance paths.

> ---
>  drivers/iio/accel/sca3000.c | 82 ++++++++++++++-----------------------
>  1 file changed, 30 insertions(+), 52 deletions(-)
> 
> diff --git a/drivers/iio/accel/sca3000.c b/drivers/iio/accel/sca3000.c
> index aabe4491efd7..c4b1da7f8de1 100644
> --- a/drivers/iio/accel/sca3000.c
> +++ b/drivers/iio/accel/sca3000.c
> @@ -281,10 +281,11 @@ static int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val)
>  	return spi_write(st->us, st->tx, 2);
>  }
>  
> -static int sca3000_read_data_short(struct sca3000_state *st,
> -				   u8 reg_address_high,
> -				   int len)
> +static int sca3000_read_data(struct sca3000_state *st,
> +			     u8 reg_address_high,
> +			     int len)
>  {
> +	int ret;
>  	struct spi_transfer xfer[2] = {
>  		{
>  			.len = 1,
> @@ -296,7 +297,10 @@ static int sca3000_read_data_short(struct sca3000_state *st,
>  	};
>  	st->tx[0] = SCA3000_READ_REG(reg_address_high);
>  
> -	return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
> +	ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
> +	if (ret)
> +		dev_err(&st->us->dev, "problem reading register\n");
> +	return ret;
>  }
>  
>  /**
> @@ -309,7 +313,7 @@ static int sca3000_reg_lock_on(struct sca3000_state *st)
>  {
>  	int ret;
>  
> -	ret = sca3000_read_data_short(st, SCA3000_REG_STATUS_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_STATUS_ADDR, 1);
As above this could be simply
	ret = spi_w8r8(st->spi, SCA3000_READ_REG(SCA3000_REG_STATUS_ADDR));
	if (ret)
		return ret;
	return !(ret & SCA3000_LOCKED);


I think...
You will want to walk through how that helper is implemented to check it
ends up doing the same thing as the existing code though and remove
st->rx as part of the conversion.


>  	if (ret < 0)
>  		return ret;
>  
> @@ -412,7 +416,7 @@ static int sca3000_read_ctrl_reg(struct sca3000_state *st,
>  	ret = sca3000_write_reg(st, SCA3000_REG_CTRL_SEL_ADDR, ctrl_reg);
>  	if (ret)
>  		goto error_ret;
> -	ret = sca3000_read_data_short(st, SCA3000_REG_CTRL_DATA_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_CTRL_DATA_ADDR, 1);
>  	if (ret)
>  		goto error_ret;
>  	return st->rx[0];
> @@ -432,7 +436,7 @@ static int sca3000_print_rev(struct iio_dev *indio_dev)
>  	struct sca3000_state *st = iio_priv(indio_dev);
>  
>  	mutex_lock(&st->lock);
> -	ret = sca3000_read_data_short(st, SCA3000_REG_REVID_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_REVID_ADDR, 1);
>  	if (ret < 0)
>  		goto error_ret;
>  	dev_info(&indio_dev->dev,
> @@ -575,7 +579,7 @@ static inline int __sca3000_get_base_freq(struct sca3000_state *st,
>  {
>  	int ret;
>  
> -	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
>  	if (ret)
>  		goto error_ret;
>  	switch (SCA3000_REG_MODE_MODE_MASK & st->rx[0]) {
> @@ -665,7 +669,7 @@ static int sca3000_read_3db_freq(struct sca3000_state *st, int *val)
>  {
>  	int ret;
>  
> -	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
>  	if (ret)
>  		return ret;
>  
> @@ -703,7 +707,7 @@ static int sca3000_write_3db_freq(struct sca3000_state *st, int val)
>  		mode = SCA3000_REG_MODE_MEAS_MODE_OP_2;
>  	else
>  		return -EINVAL;
> -	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
>  	if (ret)
>  		return ret;
>  
> @@ -732,7 +736,7 @@ static int sca3000_read_raw(struct iio_dev *indio_dev,
>  				return -EBUSY;
>  			}
>  			address = sca3000_addresses[chan->address][0];
> -			ret = sca3000_read_data_short(st, address, 2);
> +			ret = sca3000_read_data(st, address, 2);
>  			if (ret < 0) {
>  				mutex_unlock(&st->lock);
>  				return ret;
> @@ -742,7 +746,7 @@ static int sca3000_read_raw(struct iio_dev *indio_dev,
>  					     chan->scan_type.realbits - 1);
>  		} else {
>  			/* get the temperature when available */
> -			ret = sca3000_read_data_short(st,
> +			ret = sca3000_read_data(st,
>  						      SCA3000_REG_TEMP_MSB_ADDR,
>  						      2);

For this spi_w8r16() may be applicable.


>  			if (ret < 0) {
> @@ -830,7 +834,7 @@ static ssize_t sca3000_read_av_freq(struct device *dev,
>  	int len = 0, ret, val;
>  
>  	mutex_lock(&st->lock);
> -	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
> +	ret = sca3000_read_data(st, SCA3000_REG_MODE_ADDR, 1);
>  	val = st->rx[0];
>  	mutex_unlock(&st->lock);
>  	if (ret)
> @@ -969,32 +973,6 @@ static const struct attribute_group sca3000_attribute_group = {
>  	.attrs = sca3000_attributes,
>  };
>  
> -static int sca3000_read_data(struct sca3000_state *st,
> -			     u8 reg_address_high,
> -			     u8 *rx,
> -			     int len)
> -{
> -	int ret;
> -	struct spi_transfer xfer[2] = {
> -		{
> -			.len = 1,
> -			.tx_buf = st->tx,
> -		}, {
> -			.len = len,
> -			.rx_buf = rx,
> -		}
> -	};
> -
> -	st->tx[0] = SCA3000_READ_REG(reg_address_high);
> -	ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
> -	if (ret) {
> -		dev_err(&st->us->dev, "problem reading register\n");
> -		return ret;
> -	}
> -
> -	return 0;
> -}
> -
>  /**
>   * sca3000_ring_int_process() - ring specific interrupt handling.
>   * @val: Value of the interrupt status register.
> @@ -1008,7 +986,7 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
>  	mutex_lock(&st->lock);
>  
>  	if (val & SCA3000_REG_INT_STATUS_HALF) {
> -		ret = sca3000_read_data_short(st, SCA3000_REG_BUF_COUNT_ADDR,
> +		ret = sca3000_read_data(st, SCA3000_REG_BUF_COUNT_ADDR,
>  					      1);
>  		if (ret)
>  			goto error_ret;
> @@ -1017,7 +995,7 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
>  		 * num_available is the total number of samples available
>  		 * i.e. number of time points * number of channels.
>  		 */
> -		ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR, st->rx,
> +		ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR,
>  					num_available * 2);
This is the one case were spi_write_then_read() is probably not appropriate due to the
large buffers that are potentially involved.
I think this will be the only remaining case to use the old infrastructure.

Thanks,

Jonathan