2022-08-09 22:02:28

by Eddie James

[permalink] [raw]
Subject: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure

Move the startup procedure into a function, and correct a missing
check on the return code for writing the PRS_CFG register.

Signed-off-by: Eddie James <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
---
drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
1 file changed, 99 insertions(+), 89 deletions(-)

diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
index 36fb7ae0d0a9..c706a8b423b5 100644
--- a/drivers/iio/pressure/dps310.c
+++ b/drivers/iio/pressure/dps310.c
@@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
return 0;
}

+/*
+ * Some versions of the chip will read temperatures in the ~60C range when
+ * it's actually ~20C. This is the manufacturer recommended workaround
+ * to correct the issue. The registers used below are undocumented.
+ */
+static int dps310_temp_workaround(struct dps310_data *data)
+{
+ int rc;
+ int reg;
+
+ rc = regmap_read(data->regmap, 0x32, &reg);
+ if (rc)
+ return rc;
+
+ /*
+ * If bit 1 is set then the device is okay, and the workaround does not
+ * need to be applied
+ */
+ if (reg & BIT(1))
+ return 0;
+
+ rc = regmap_write(data->regmap, 0x0e, 0xA5);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x0f, 0x96);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x62, 0x02);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(data->regmap, 0x0e, 0x00);
+ if (rc)
+ return rc;
+
+ return regmap_write(data->regmap, 0x0f, 0x00);
+}
+
+static int dps310_startup(struct dps310_data *data)
+{
+ int rc;
+ int ready;
+
+ /*
+ * Set up pressure sensor in single sample, one measurement per second
+ * mode
+ */
+ rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
+ if (rc)
+ return rc;
+
+ /*
+ * Set up external (MEMS) temperature sensor in single sample, one
+ * measurement per second mode
+ */
+ rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
+ if (rc)
+ return rc;
+
+ /* Temp and pressure shifts are disabled when PRC <= 8 */
+ rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
+ DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
+ if (rc)
+ return rc;
+
+ /* MEAS_CFG doesn't update correctly unless first written with 0 */
+ rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
+ DPS310_MEAS_CTRL_BITS, 0);
+ if (rc)
+ return rc;
+
+ /* Turn on temperature and pressure measurement in the background */
+ rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
+ DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
+ DPS310_TEMP_EN | DPS310_BACKGROUND);
+ if (rc)
+ return rc;
+
+ /*
+ * Calibration coefficients required for reporting temperature.
+ * They are available 40ms after the device has started
+ */
+ rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
+ ready & DPS310_COEF_RDY, 10000, 40000);
+ if (rc)
+ return rc;
+
+ rc = dps310_get_coefs(data);
+ if (rc)
+ return rc;
+
+ return dps310_temp_workaround(data);
+}
+
static int dps310_get_pres_precision(struct dps310_data *data)
{
int rc;
@@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
.write_raw = dps310_write_raw,
};

-/*
- * Some verions of chip will read temperatures in the ~60C range when
- * its actually ~20C. This is the manufacturer recommended workaround
- * to correct the issue. The registers used below are undocumented.
- */
-static int dps310_temp_workaround(struct dps310_data *data)
-{
- int rc;
- int reg;
-
- rc = regmap_read(data->regmap, 0x32, &reg);
- if (rc < 0)
- return rc;
-
- /*
- * If bit 1 is set then the device is okay, and the workaround does not
- * need to be applied
- */
- if (reg & BIT(1))
- return 0;
-
- rc = regmap_write(data->regmap, 0x0e, 0xA5);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x0f, 0x96);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x62, 0x02);
- if (rc < 0)
- return rc;
-
- rc = regmap_write(data->regmap, 0x0e, 0x00);
- if (rc < 0)
- return rc;
-
- return regmap_write(data->regmap, 0x0f, 0x00);
-}
-
static int dps310_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct dps310_data *data;
struct iio_dev *iio;
- int rc, ready;
+ int rc;

iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!iio)
@@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
if (rc)
return rc;

- /*
- * Set up pressure sensor in single sample, one measurement per second
- * mode
- */
- rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
-
- /*
- * Set up external (MEMS) temperature sensor in single sample, one
- * measurement per second mode
- */
- rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
- if (rc < 0)
- return rc;
-
- /* Temp and pressure shifts are disabled when PRC <= 8 */
- rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
- DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
- if (rc < 0)
- return rc;
-
- /* MEAS_CFG doesn't update correctly unless first written with 0 */
- rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
- DPS310_MEAS_CTRL_BITS, 0);
- if (rc < 0)
- return rc;
-
- /* Turn on temperature and pressure measurement in the background */
- rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
- DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
- DPS310_TEMP_EN | DPS310_BACKGROUND);
- if (rc < 0)
- return rc;
-
- /*
- * Calibration coefficients required for reporting temperature.
- * They are available 40ms after the device has started
- */
- rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
- ready & DPS310_COEF_RDY, 10000, 40000);
- if (rc < 0)
- return rc;
-
- rc = dps310_get_coefs(data);
- if (rc < 0)
- return rc;
-
- rc = dps310_temp_workaround(data);
- if (rc < 0)
+ rc = dps310_startup(data);
+ if (rc)
return rc;

rc = devm_iio_device_register(&client->dev, iio);
--
2.31.1


2022-08-12 22:26:33

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure

On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> wrote:
>
> Move the startup procedure into a function, and correct a missing
> check on the return code for writing the PRS_CFG register.

Code looks good, one remark below.
Reviewed-by: Andy Shevchenko <[email protected]>

> Signed-off-by: Eddie James <[email protected]>
> Reviewed-by: Joel Stanley <[email protected]>
> ---
> drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
> 1 file changed, 99 insertions(+), 89 deletions(-)
>
> diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
> index 36fb7ae0d0a9..c706a8b423b5 100644
> --- a/drivers/iio/pressure/dps310.c
> +++ b/drivers/iio/pressure/dps310.c
> @@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
> return 0;
> }
>
> +/*
> + * Some versions of the chip will read temperatures in the ~60C range when
> + * it's actually ~20C. This is the manufacturer recommended workaround
> + * to correct the issue. The registers used below are undocumented.
> + */
> +static int dps310_temp_workaround(struct dps310_data *data)
> +{
> + int rc;
> + int reg;
> +
> + rc = regmap_read(data->regmap, 0x32, &reg);
> + if (rc)
> + return rc;
> +
> + /*
> + * If bit 1 is set then the device is okay, and the workaround does not
> + * need to be applied
> + */
> + if (reg & BIT(1))
> + return 0;
> +
> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> + if (rc)
> + return rc;
> +
> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> + if (rc)
> + return rc;

This code already exists, but still want to ask, is it really
byte-registers here and not be16/le16 one? In such a case perhaps bulk
write can be used to reflect it better?

> + rc = regmap_write(data->regmap, 0x62, 0x02);
> + if (rc)
> + return rc;
> +
> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> + if (rc)
> + return rc;
> +
> + return regmap_write(data->regmap, 0x0f, 0x00);

Ditto.

> +}
> +
> +static int dps310_startup(struct dps310_data *data)
> +{
> + int rc;
> + int ready;
> +
> + /*
> + * Set up pressure sensor in single sample, one measurement per second
> + * mode
> + */
> + rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
> + if (rc)
> + return rc;
> +
> + /*
> + * Set up external (MEMS) temperature sensor in single sample, one
> + * measurement per second mode
> + */
> + rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
> + if (rc)
> + return rc;
> +
> + /* Temp and pressure shifts are disabled when PRC <= 8 */
> + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
> + DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
> + if (rc)
> + return rc;
> +
> + /* MEAS_CFG doesn't update correctly unless first written with 0 */
> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> + DPS310_MEAS_CTRL_BITS, 0);
> + if (rc)
> + return rc;
> +
> + /* Turn on temperature and pressure measurement in the background */
> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> + DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
> + DPS310_TEMP_EN | DPS310_BACKGROUND);
> + if (rc)
> + return rc;
> +
> + /*
> + * Calibration coefficients required for reporting temperature.
> + * They are available 40ms after the device has started
> + */
> + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
> + ready & DPS310_COEF_RDY, 10000, 40000);
> + if (rc)
> + return rc;
> +
> + rc = dps310_get_coefs(data);
> + if (rc)
> + return rc;
> +
> + return dps310_temp_workaround(data);
> +}
> +
> static int dps310_get_pres_precision(struct dps310_data *data)
> {
> int rc;
> @@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
> .write_raw = dps310_write_raw,
> };
>
> -/*
> - * Some verions of chip will read temperatures in the ~60C range when
> - * its actually ~20C. This is the manufacturer recommended workaround
> - * to correct the issue. The registers used below are undocumented.
> - */
> -static int dps310_temp_workaround(struct dps310_data *data)
> -{
> - int rc;
> - int reg;
> -
> - rc = regmap_read(data->regmap, 0x32, &reg);
> - if (rc < 0)
> - return rc;
> -
> - /*
> - * If bit 1 is set then the device is okay, and the workaround does not
> - * need to be applied
> - */
> - if (reg & BIT(1))
> - return 0;
> -
> - rc = regmap_write(data->regmap, 0x0e, 0xA5);
> - if (rc < 0)
> - return rc;
> -
> - rc = regmap_write(data->regmap, 0x0f, 0x96);
> - if (rc < 0)
> - return rc;
> -
> - rc = regmap_write(data->regmap, 0x62, 0x02);
> - if (rc < 0)
> - return rc;
> -
> - rc = regmap_write(data->regmap, 0x0e, 0x00);
> - if (rc < 0)
> - return rc;
> -
> - return regmap_write(data->regmap, 0x0f, 0x00);
> -}
> -
> static int dps310_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> struct dps310_data *data;
> struct iio_dev *iio;
> - int rc, ready;
> + int rc;
>
> iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
> if (!iio)
> @@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
> if (rc)
> return rc;
>
> - /*
> - * Set up pressure sensor in single sample, one measurement per second
> - * mode
> - */
> - rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
> -
> - /*
> - * Set up external (MEMS) temperature sensor in single sample, one
> - * measurement per second mode
> - */
> - rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
> - if (rc < 0)
> - return rc;
> -
> - /* Temp and pressure shifts are disabled when PRC <= 8 */
> - rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
> - DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
> - if (rc < 0)
> - return rc;
> -
> - /* MEAS_CFG doesn't update correctly unless first written with 0 */
> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> - DPS310_MEAS_CTRL_BITS, 0);
> - if (rc < 0)
> - return rc;
> -
> - /* Turn on temperature and pressure measurement in the background */
> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
> - DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
> - DPS310_TEMP_EN | DPS310_BACKGROUND);
> - if (rc < 0)
> - return rc;
> -
> - /*
> - * Calibration coefficients required for reporting temperature.
> - * They are available 40ms after the device has started
> - */
> - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
> - ready & DPS310_COEF_RDY, 10000, 40000);
> - if (rc < 0)
> - return rc;
> -
> - rc = dps310_get_coefs(data);
> - if (rc < 0)
> - return rc;
> -
> - rc = dps310_temp_workaround(data);
> - if (rc < 0)
> + rc = dps310_startup(data);
> + if (rc)
> return rc;
>
> rc = devm_iio_device_register(&client->dev, iio);
> --
> 2.31.1
>


--
With Best Regards,
Andy Shevchenko

2022-08-15 13:48:24

by Eddie James

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure


On 8/12/22 17:03, Andy Shevchenko wrote:
> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> wrote:
>> Move the startup procedure into a function, and correct a missing
>> check on the return code for writing the PRS_CFG register.
> Code looks good, one remark below.
> Reviewed-by: Andy Shevchenko <[email protected]>
>
>> Signed-off-by: Eddie James <[email protected]>
>> Reviewed-by: Joel Stanley <[email protected]>
>> ---
>> drivers/iio/pressure/dps310.c | 188 ++++++++++++++++++----------------
>> 1 file changed, 99 insertions(+), 89 deletions(-)
>>
>> diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
>> index 36fb7ae0d0a9..c706a8b423b5 100644
>> --- a/drivers/iio/pressure/dps310.c
>> +++ b/drivers/iio/pressure/dps310.c
>> @@ -159,6 +159,102 @@ static int dps310_get_coefs(struct dps310_data *data)
>> return 0;
>> }
>>
>> +/*
>> + * Some versions of the chip will read temperatures in the ~60C range when
>> + * it's actually ~20C. This is the manufacturer recommended workaround
>> + * to correct the issue. The registers used below are undocumented.
>> + */
>> +static int dps310_temp_workaround(struct dps310_data *data)
>> +{
>> + int rc;
>> + int reg;
>> +
>> + rc = regmap_read(data->regmap, 0x32, &reg);
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * If bit 1 is set then the device is okay, and the workaround does not
>> + * need to be applied
>> + */
>> + if (reg & BIT(1))
>> + return 0;
>> +
>> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
>> + if (rc)
>> + return rc;
>> +
>> + rc = regmap_write(data->regmap, 0x0f, 0x96);
>> + if (rc)
>> + return rc;
> This code already exists, but still want to ask, is it really
> byte-registers here and not be16/le16 one? In such a case perhaps bulk
> write can be used to reflect it better?


The temperature and pressure regs are 24 bits big endian, and all the
rest are 8 bits. I think the existing approach is best.


Thanks Andy!


>
>> + rc = regmap_write(data->regmap, 0x62, 0x02);
>> + if (rc)
>> + return rc;
>> +
>> + rc = regmap_write(data->regmap, 0x0e, 0x00);
>> + if (rc)
>> + return rc;
>> +
>> + return regmap_write(data->regmap, 0x0f, 0x00);
> Ditto.
>
>> +}
>> +
>> +static int dps310_startup(struct dps310_data *data)
>> +{
>> + int rc;
>> + int ready;
>> +
>> + /*
>> + * Set up pressure sensor in single sample, one measurement per second
>> + * mode
>> + */
>> + rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * Set up external (MEMS) temperature sensor in single sample, one
>> + * measurement per second mode
>> + */
>> + rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
>> + if (rc)
>> + return rc;
>> +
>> + /* Temp and pressure shifts are disabled when PRC <= 8 */
>> + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
>> + DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
>> + if (rc)
>> + return rc;
>> +
>> + /* MEAS_CFG doesn't update correctly unless first written with 0 */
>> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> + DPS310_MEAS_CTRL_BITS, 0);
>> + if (rc)
>> + return rc;
>> +
>> + /* Turn on temperature and pressure measurement in the background */
>> + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> + DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
>> + DPS310_TEMP_EN | DPS310_BACKGROUND);
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * Calibration coefficients required for reporting temperature.
>> + * They are available 40ms after the device has started
>> + */
>> + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
>> + ready & DPS310_COEF_RDY, 10000, 40000);
>> + if (rc)
>> + return rc;
>> +
>> + rc = dps310_get_coefs(data);
>> + if (rc)
>> + return rc;
>> +
>> + return dps310_temp_workaround(data);
>> +}
>> +
>> static int dps310_get_pres_precision(struct dps310_data *data)
>> {
>> int rc;
>> @@ -677,52 +773,12 @@ static const struct iio_info dps310_info = {
>> .write_raw = dps310_write_raw,
>> };
>>
>> -/*
>> - * Some verions of chip will read temperatures in the ~60C range when
>> - * its actually ~20C. This is the manufacturer recommended workaround
>> - * to correct the issue. The registers used below are undocumented.
>> - */
>> -static int dps310_temp_workaround(struct dps310_data *data)
>> -{
>> - int rc;
>> - int reg;
>> -
>> - rc = regmap_read(data->regmap, 0x32, &reg);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /*
>> - * If bit 1 is set then the device is okay, and the workaround does not
>> - * need to be applied
>> - */
>> - if (reg & BIT(1))
>> - return 0;
>> -
>> - rc = regmap_write(data->regmap, 0x0e, 0xA5);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = regmap_write(data->regmap, 0x0f, 0x96);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = regmap_write(data->regmap, 0x62, 0x02);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = regmap_write(data->regmap, 0x0e, 0x00);
>> - if (rc < 0)
>> - return rc;
>> -
>> - return regmap_write(data->regmap, 0x0f, 0x00);
>> -}
>> -
>> static int dps310_probe(struct i2c_client *client,
>> const struct i2c_device_id *id)
>> {
>> struct dps310_data *data;
>> struct iio_dev *iio;
>> - int rc, ready;
>> + int rc;
>>
>> iio = devm_iio_device_alloc(&client->dev, sizeof(*data));
>> if (!iio)
>> @@ -747,54 +803,8 @@ static int dps310_probe(struct i2c_client *client,
>> if (rc)
>> return rc;
>>
>> - /*
>> - * Set up pressure sensor in single sample, one measurement per second
>> - * mode
>> - */
>> - rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0);
>> -
>> - /*
>> - * Set up external (MEMS) temperature sensor in single sample, one
>> - * measurement per second mode
>> - */
>> - rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /* Temp and pressure shifts are disabled when PRC <= 8 */
>> - rc = regmap_write_bits(data->regmap, DPS310_CFG_REG,
>> - DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /* MEAS_CFG doesn't update correctly unless first written with 0 */
>> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> - DPS310_MEAS_CTRL_BITS, 0);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /* Turn on temperature and pressure measurement in the background */
>> - rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG,
>> - DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN |
>> - DPS310_TEMP_EN | DPS310_BACKGROUND);
>> - if (rc < 0)
>> - return rc;
>> -
>> - /*
>> - * Calibration coefficients required for reporting temperature.
>> - * They are available 40ms after the device has started
>> - */
>> - rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready,
>> - ready & DPS310_COEF_RDY, 10000, 40000);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = dps310_get_coefs(data);
>> - if (rc < 0)
>> - return rc;
>> -
>> - rc = dps310_temp_workaround(data);
>> - if (rc < 0)
>> + rc = dps310_startup(data);
>> + if (rc)
>> return rc;
>>
>> rc = devm_iio_device_register(&client->dev, iio);
>> --
>> 2.31.1
>>
>

2022-08-19 09:53:20

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure

On Mon, Aug 15, 2022 at 4:42 PM Eddie James <[email protected]> wrote:
> On 8/12/22 17:03, Andy Shevchenko wrote:
> > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> wrote:

...

> >> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> >> + if (rc)
> >> + return rc;
> >> +
> >> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> >> + if (rc)
> >> + return rc;
> > This code already exists, but still want to ask, is it really
> > byte-registers here and not be16/le16 one? In such a case perhaps bulk
> > write can be used to reflect it better?
>
> The temperature and pressure regs are 24 bits big endian, and all the
> rest are 8 bits. I think the existing approach is best.

It doesn't look like you got what I was meaning... Or I misunderstood
what you said.

The code above writes two byte values to two sequential registers
which make me think that they are 16-bit registers at offset 0x0e.

...

> >> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> >> + if (rc)
> >> + return rc;
> >> +
> >> + return regmap_write(data->regmap, 0x0f, 0x00);

Ditto.

--
With Best Regards,
Andy Shevchenko

2022-08-20 11:59:19

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure

On Fri, 19 Aug 2022 12:42:00 +0300
Andy Shevchenko <[email protected]> wrote:

> On Mon, Aug 15, 2022 at 4:42 PM Eddie James <[email protected]> wrote:
> > On 8/12/22 17:03, Andy Shevchenko wrote:
> > > On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> wrote:
>
> ...
>
> > >> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> > >> + if (rc)
> > >> + return rc;
> > >> +
> > >> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> > >> + if (rc)
> > >> + return rc;
> > > This code already exists, but still want to ask, is it really
> > > byte-registers here and not be16/le16 one? In such a case perhaps bulk
> > > write can be used to reflect it better?
> >
> > The temperature and pressure regs are 24 bits big endian, and all the
> > rest are 8 bits. I think the existing approach is best.
>
> It doesn't look like you got what I was meaning... Or I misunderstood
> what you said.
>
> The code above writes two byte values to two sequential registers
> which make me think that they are 16-bit registers at offset 0x0e.

Given they are undocumented, this is guessing territory.
Probably best to just leave them as is.
You could do a bulk write on an array though as that implies
nothing about what's in the registers -just that they happen
to be next to each other.

>
> ...
>
> > >> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> > >> + if (rc)
> > >> + return rc;
> > >> +
> > >> + return regmap_write(data->regmap, 0x0f, 0x00);
>
> Ditto.
>

2022-09-06 20:21:03

by Eddie James

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure


On 8/20/22 06:49, Jonathan Cameron wrote:
> On Fri, 19 Aug 2022 12:42:00 +0300
> Andy Shevchenko <[email protected]> wrote:
>
>> On Mon, Aug 15, 2022 at 4:42 PM Eddie James <[email protected]> wrote:
>>> On 8/12/22 17:03, Andy Shevchenko wrote:
>>>> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> wrote:
>> ...
>>
>>>>> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
>>>>> + if (rc)
>>>>> + return rc;
>>>>> +
>>>>> + rc = regmap_write(data->regmap, 0x0f, 0x96);
>>>>> + if (rc)
>>>>> + return rc;
>>>> This code already exists, but still want to ask, is it really
>>>> byte-registers here and not be16/le16 one? In such a case perhaps bulk
>>>> write can be used to reflect it better?
>>> The temperature and pressure regs are 24 bits big endian, and all the
>>> rest are 8 bits. I think the existing approach is best.
>> It doesn't look like you got what I was meaning... Or I misunderstood
>> what you said.
>>
>> The code above writes two byte values to two sequential registers
>> which make me think that they are 16-bit registers at offset 0x0e.
> Given they are undocumented, this is guessing territory.
> Probably best to just leave them as is.
> You could do a bulk write on an array though as that implies
> nothing about what's in the registers -just that they happen
> to be next to each other.


Indeed. Is it worth it to switch to bulk write for two 2-byte writes?
I'm inclined to say no and will leave this as-is for v6, but if you
think it is, I can switch it.


Thanks,

Eddie


>
>> ...
>>
>>>>> + rc = regmap_write(data->regmap, 0x0e, 0x00);
>>>>> + if (rc)
>>>>> + return rc;
>>>>> +
>>>>> + return regmap_write(data->regmap, 0x0f, 0x00);
>> Ditto.
>>

2022-09-11 10:36:58

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] iio: pressure: dps310: Refactor startup procedure

On Tue, 6 Sep 2022 14:48:20 -0500
Eddie James <[email protected]> wrote:

> On 8/20/22 06:49, Jonathan Cameron wrote:
> > On Fri, 19 Aug 2022 12:42:00 +0300
> > Andy Shevchenko <[email protected]> wrote:
> >
> >> On Mon, Aug 15, 2022 at 4:42 PM Eddie James <[email protected]> wrote:
> >>> On 8/12/22 17:03, Andy Shevchenko wrote:
> >>>> On Wed, Aug 10, 2022 at 12:12 AM Eddie James <[email protected]> wrote:
> >> ...
> >>
> >>>>> + rc = regmap_write(data->regmap, 0x0e, 0xA5);
> >>>>> + if (rc)
> >>>>> + return rc;
> >>>>> +
> >>>>> + rc = regmap_write(data->regmap, 0x0f, 0x96);
> >>>>> + if (rc)
> >>>>> + return rc;
> >>>> This code already exists, but still want to ask, is it really
> >>>> byte-registers here and not be16/le16 one? In such a case perhaps bulk
> >>>> write can be used to reflect it better?
> >>> The temperature and pressure regs are 24 bits big endian, and all the
> >>> rest are 8 bits. I think the existing approach is best.
> >> It doesn't look like you got what I was meaning... Or I misunderstood
> >> what you said.
> >>
> >> The code above writes two byte values to two sequential registers
> >> which make me think that they are 16-bit registers at offset 0x0e.
> > Given they are undocumented, this is guessing territory.
> > Probably best to just leave them as is.
> > You could do a bulk write on an array though as that implies
> > nothing about what's in the registers -just that they happen
> > to be next to each other.
>
>
> Indeed. Is it worth it to switch to bulk write for two 2-byte writes?
> I'm inclined to say no and will leave this as-is for v6, but if you
> think it is, I can switch it.
>

As far as I'm concerned, fine either way.

Jonathan

>
> Thanks,
>
> Eddie
>
>
> >
> >> ...
> >>
> >>>>> + rc = regmap_write(data->regmap, 0x0e, 0x00);
> >>>>> + if (rc)
> >>>>> + return rc;
> >>>>> +
> >>>>> + return regmap_write(data->regmap, 0x0f, 0x00);
> >> Ditto.
> >>