[PATCH v6 07/10] iio: adc: ad_sigma_delta: Store information about reset sequence length

Uwe Kleine-König
2024-12-06T17:29:24Z

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 R̅D̅Y̅ 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 | 5 ++---
include/linux/iio/adc/ad_sigma_delta.h | 5 +++--
7 files changed, 14 insertions(+), 8 deletions(-)

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 a0fca16c3be0..ca46bb20288d 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -764,6 +764,7 @@ 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 955e9eff0099..f744441bd13f 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 5d2ad3dd6caa..897e628de611 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 b86e89370e0d..5f15fd7aab74 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 a4c31baa9c9e..101cf30f4458 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -178,13 +178,12 @@ EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, IIO_AD_SIGMA_DELTA);
* ad_sd_reset() - Reset the serial interface
*
* @sigma_delta: The sigma delta device
- * @reset_length: Number of SCLKs with DIN = 1
*
* 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;
uint8_t *buf;
unsigned int size;
int ret;
diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h
index f86eca6126b4..eef87d04eb6b 100644
--- a/include/linux/iio/adc/ad_sigma_delta.h
+++ b/include/linux/iio/adc/ad_sigma_delta.h
@@ -54,6 +54,7 @@ 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);
@@ -70,6 +71,7 @@ struct ad_sigma_delta_info {
unsigned long irq_flags;
unsigned int num_slots;
int irq_line;
+ unsigned int num_resetclks;
};

/**
@@ -181,8 +183,7 @@ 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);
--
2.45.2