diff mbox series

[v3,07/10] iio: adc: ad_sigma_delta: Store information about reset sequence length

Message ID 20241122113322.242875-19-u.kleine-koenig@baylibre.com (mailing list archive)
State New
Headers show
Series iio: adc: ad7124: Various fixes | expand

Commit Message

Uwe Kleine-König Nov. 22, 2024, 11:33 a.m. UTC 
The various chips can be reset using a sequence of SPI transfers with
MOSI = 1. The length of such a sequence varies from chip to chip. Store
that length in struct ad_sigma_delta_info and replace the respective
parameter to ad_sd_reset() with it.

Note the ad7192 used to pass 48 as length but the documentation
specifies 40 as the required length. Assuming the latter is right.
(Using a too long sequence doesn't hurt apart from using a longer spi
transfer than necessary, so this is no relevant fix.)

The motivation for storing this information is that this is useful to
clear a pending RDY signal in the next change.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/iio/adc/ad7124.c               | 3 ++-
 drivers/iio/adc/ad7173.c               | 1 +
 drivers/iio/adc/ad7192.c               | 4 +++-
 drivers/iio/adc/ad7791.c               | 1 +
 drivers/iio/adc/ad7793.c               | 3 ++-
 drivers/iio/adc/ad_sigma_delta.c       | 7 +++----
 include/linux/iio/adc/ad_sigma_delta.h | 5 +++--
 7 files changed, 15 insertions(+), 9 deletions(-)

Comments

Andy Shevchenko Nov. 22, 2024, 8:07 p.m. UTC | #1 
On Fri, Nov 22, 2024 at 1:34 PM Uwe Kleine-König
<u.kleine-koenig@baylibre.com> wrote:
>
> The various chips can be reset using a sequence of SPI transfers with
> MOSI = 1. The length of such a sequence varies from chip to chip. Store
> that length in struct ad_sigma_delta_info and replace the respective
> parameter to ad_sd_reset() with it.
>
> Note the ad7192 used to pass 48 as length but the documentation
> specifies 40 as the required length. Assuming the latter is right.
> (Using a too long sequence doesn't hurt apart from using a longer spi
> transfer than necessary, so this is no relevant fix.)
>
> The motivation for storing this information is that this is useful to
> clear a pending RDY signal in the next change.

...

> @@ -182,14 +182,13 @@ EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, IIO_AD_SIGMA_DELTA);
>   *
>   * Returns 0 on success, an error code otherwise.

>   **/

JFYI: unneeded asterisk.

...

> +       unsigned int size = DIV_ROUND_UP(reset_length, 8);
>         uint8_t *buf;
> -       unsigned int size;
>         int ret;
>
> -       size = DIV_ROUND_UP(reset_length, 8);
>         buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
>         if (!buf)
>                 return -ENOMEM;

This is somewhat like unrelated refactoring.

I would suggest avoiding doing it here and instead add a change that
either uses BITS_TO_BYTES() or even bitmap_zalloc(), whoever the
latter might require more changes in the code.
diff mbox series

Patch

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index 1f3342373f1c..b17c3dbeaeba 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -571,6 +571,7 @@  static const struct ad_sigma_delta_info ad7124_sigma_delta_info = {
 	.data_reg = AD7124_DATA,
 	.num_slots = 8,
 	.irq_flags = IRQF_TRIGGER_FALLING,
+	.num_resetclks = 64,
 };
 
 static int ad7124_read_raw(struct iio_dev *indio_dev,
@@ -756,7 +757,7 @@  static int ad7124_soft_reset(struct ad7124_state *st)
 	unsigned int readval, timeout;
 	int ret;
 
-	ret = ad_sd_reset(&st->sd, 64);
+	ret = ad_sd_reset(&st->sd);
 	if (ret < 0)
 		return ret;
 
diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 0702ec71aa29..2550194efee8 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -744,6 +744,7 @@  static struct ad_sigma_delta_info ad7173_sigma_delta_info = {
 	.read_mask = BIT(6),
 	.status_ch_mask = GENMASK(3, 0),
 	.data_reg = AD7173_REG_DATA,
+	.num_resetclks = 64,
 };
 
 static int ad7173_setup(struct iio_dev *indio_dev)
diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 7042ddfdfc03..c4dd48edd8d9 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -361,6 +361,7 @@  static const struct ad_sigma_delta_info ad7192_sigma_delta_info = {
 	.status_ch_mask = GENMASK(3, 0),
 	.num_slots = 4,
 	.irq_flags = IRQF_TRIGGER_FALLING,
+	.num_resetclks = 40,
 };
 
 static const struct ad_sigma_delta_info ad7194_sigma_delta_info = {
@@ -373,6 +374,7 @@  static const struct ad_sigma_delta_info ad7194_sigma_delta_info = {
 	.read_mask = BIT(6),
 	.status_ch_mask = GENMASK(3, 0),
 	.irq_flags = IRQF_TRIGGER_FALLING,
+	.num_resetclks = 40,
 };
 
 static const struct ad_sd_calib_data ad7192_calib_arr[8] = {
@@ -565,7 +567,7 @@  static int ad7192_setup(struct iio_dev *indio_dev, struct device *dev)
 	int i, ret, id;
 
 	/* reset the serial interface */
-	ret = ad_sd_reset(&st->sd, 48);
+	ret = ad_sd_reset(&st->sd);
 	if (ret < 0)
 		return ret;
 	usleep_range(500, 1000); /* Wait for at least 500us */
diff --git a/drivers/iio/adc/ad7791.c b/drivers/iio/adc/ad7791.c
index 86effe8501b4..c7509b911835 100644
--- a/drivers/iio/adc/ad7791.c
+++ b/drivers/iio/adc/ad7791.c
@@ -254,6 +254,7 @@  static const struct ad_sigma_delta_info ad7791_sigma_delta_info = {
 	.addr_shift = 4,
 	.read_mask = BIT(3),
 	.irq_flags = IRQF_TRIGGER_FALLING,
+	.num_resetclks = 32,
 };
 
 static int ad7791_read_raw(struct iio_dev *indio_dev,
diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
index abebd519cafa..0767c56bb442 100644
--- a/drivers/iio/adc/ad7793.c
+++ b/drivers/iio/adc/ad7793.c
@@ -206,6 +206,7 @@  static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
 	.addr_shift = 3,
 	.read_mask = BIT(6),
 	.irq_flags = IRQF_TRIGGER_FALLING,
+	.num_resetclks = 32,
 };
 
 static const struct ad_sd_calib_data ad7793_calib_arr[6] = {
@@ -265,7 +266,7 @@  static int ad7793_setup(struct iio_dev *indio_dev,
 		return ret;
 
 	/* reset the serial interface */
-	ret = ad_sd_reset(&st->sd, 32);
+	ret = ad_sd_reset(&st->sd);
 	if (ret < 0)
 		goto out;
 	usleep_range(500, 2000); /* Wait for at least 500us */
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
index fd3560beb56b..19cb9b7b62c6 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -182,14 +182,13 @@  EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, IIO_AD_SIGMA_DELTA);
  *
  * Returns 0 on success, an error code otherwise.
  **/
-int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
-	unsigned int reset_length)
+int ad_sd_reset(struct ad_sigma_delta *sigma_delta)
 {
+	unsigned int reset_length = sigma_delta->info->num_resetclks;
+	unsigned int size = DIV_ROUND_UP(reset_length, 8);
 	uint8_t *buf;
-	unsigned int size;
 	int ret;
 
-	size = DIV_ROUND_UP(reset_length, 8);
 	buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h
index b3e4d89f2d06..39bb3a6dd9cd 100644
--- a/include/linux/iio/adc/ad_sigma_delta.h
+++ b/include/linux/iio/adc/ad_sigma_delta.h
@@ -53,6 +53,7 @@  struct iio_dev;
  * @irq_flags: flags for the interrupt used by the triggered buffer
  * @num_slots: Number of sequencer slots
  * @irq_line: IRQ for reading conversions. If 0, spi->irq will be used
+ * @num_resetclks: Number of SPI clk cycles with MOSI=1 to reset the chip.
  */
 struct ad_sigma_delta_info {
 	int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
@@ -69,6 +70,7 @@  struct ad_sigma_delta_info {
 	unsigned long irq_flags;
 	unsigned int num_slots;
 	int irq_line;
+	unsigned int num_resetclks;
 };
 
 /**
@@ -180,8 +182,7 @@  int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
 	unsigned int size, unsigned int *val);
 
-int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
-	unsigned int reset_length);
+int ad_sd_reset(struct ad_sigma_delta *sigma_delta);
 
 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan, int *val);