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@xxxxxxxxxxxx>
---
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(-)
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);
--
2.45.2
