Re: [PATCH v6 2/9] iio: pressure: bmp280: use FIELD_GET, FIELD_PREP and GENMASK

From: Jonathan Cameron
Date: Thu Sep 15 2022 - 10:55:00 EST

Next message: Juergen Gross: "Re: [PATCH] xen/xenbus: fix xenbus_setup_ring()"
Previous message: Christian Borntraeger: "Re: [PATCH v3 1/2] s390/vfio-ap: bypass unnecessary processing of AP resources"
In reply to: Angel Iglesias: "[PATCH v6 2/9] iio: pressure: bmp280: use FIELD_GET, FIELD_PREP and GENMASK"
Next in thread: Angel Iglesias: "[PATCH v6 3/9] iio: pressure: bmp280: Simplify bmp280 calibration data reading"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Tue, 13 Sep 2022 01:45:49 +0200
Angel Iglesias <ang.iglesiasg@xxxxxxxxx> wrote:

> Cleaned and simplified register values construction and extraction
> converting to use FIELD_PREP and FIELD_GET macros.
>
> Replaced hardcoded bit masks with GENMASK macro.
>
> Signed-off-by: Angel Iglesias <ang.iglesiasg@xxxxxxxxx>
Random thought whilst checking this..

I wonder how many users a FIELD_GET_SIGNED() would have
with the assumption it returned a sign extended value...

Anyhow, I'm picking up these patches as I look through
them (mainly because I'm waiting for a late flight and not
sure how far I'll get!)

So applied up to here so far...

Jonathan

> ---
> drivers/iio/pressure/bmp280-core.c | 25 ++++++----
> drivers/iio/pressure/bmp280.h | 78 ++++++++++++++++--------------
> 2 files changed, 57 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 42b29f30e9d1..0ba4ff999f33 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -16,6 +16,8 @@
>
> #define pr_fmt(fmt) "bmp280: " fmt
>
> +#include <linux/bitops.h>
> +#include <linux/bitfield.h>
> #include <linux/device.h>
> #include <linux/module.h>
> #include <linux/regmap.h>
> @@ -242,7 +244,7 @@ static int bmp280_read_calib(struct bmp280_data *data,
> dev_err(dev, "failed to read H5 comp value\n");
> return ret;
> }
> - calib->H5 = sign_extend32(((le16_to_cpu(l16) >> 4) & 0xfff), 11);
> + calib->H5 = sign_extend32(FIELD_GET(BMP280_COMP_H5_MASK, le16_to_cpu(l16)), 11);
>
> ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
> if (ret < 0) {
> @@ -346,7 +348,7 @@ static int bmp280_read_temp(struct bmp280_data *data,
> return ret;
> }
>
> - adc_temp = be32_to_cpu(tmp) >> 12;
> + adc_temp = FIELD_GET(BMP280_MEAS_TRIM_MASK, be32_to_cpu(tmp));
> if (adc_temp == BMP280_TEMP_SKIPPED) {
> /* reading was skipped */
> dev_err(data->dev, "reading temperature skipped\n");
> @@ -385,7 +387,7 @@ static int bmp280_read_press(struct bmp280_data *data,
> return ret;
> }
>
> - adc_press = be32_to_cpu(tmp) >> 12;
> + adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, be32_to_cpu(tmp));
> if (adc_press == BMP280_PRESS_SKIPPED) {
> /* reading was skipped */
> dev_err(data->dev, "reading pressure skipped\n");
> @@ -611,8 +613,8 @@ static const struct iio_info bmp280_info = {
>
> static int bmp280_chip_config(struct bmp280_data *data)
> {
> - u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
> - BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
> + u8 osrs = FIELD_PREP(BMP280_OSRS_TEMP_MASK, data->oversampling_temp + 1) |
> + FIELD_PREP(BMP280_OSRS_PRESS_MASK, data->oversampling_press + 1);
> int ret;
>
> ret = regmap_write_bits(data->regmap, BMP280_REG_CTRL_MEAS,
> @@ -654,7 +656,7 @@ static const struct bmp280_chip_info bmp280_chip_info = {
>
> static int bme280_chip_config(struct bmp280_data *data)
> {
> - u8 osrs = BMP280_OSRS_HUMIDITIY_X(data->oversampling_humid + 1);
> + u8 osrs = FIELD_PREP(BMP280_OSRS_HUMIDITY_MASK, data->oversampling_humid + 1);
> int ret;
>
> /*
> @@ -711,7 +713,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
> if (!ret)
> dev_err(data->dev, "timeout waiting for completion\n");
> } else {
> - if (ctrl_meas == BMP180_MEAS_TEMP)
> + if (FIELD_GET(BMP180_MEAS_CTRL_MASK, ctrl_meas) == BMP180_MEAS_TEMP)
> delay_us = 4500;
> else
> delay_us =
> @@ -736,7 +738,9 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
> __be16 tmp;
> int ret;
>
> - ret = bmp180_measure(data, BMP180_MEAS_TEMP);
> + ret = bmp180_measure(data,
> + FIELD_PREP(BMP180_MEAS_CTRL_MASK, BMP180_MEAS_TEMP) |
> + BMP180_MEAS_SCO);
> if (ret)
> return ret;
>
> @@ -833,7 +837,10 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
> __be32 tmp = 0;
> int ret;
>
> - ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
> + ret = bmp180_measure(data,
> + FIELD_PREP(BMP180_MEAS_CTRL_MASK, BMP180_MEAS_PRESS) |
> + FIELD_PREP(BMP180_OSRS_PRESS_MASK, oss) |
> + BMP180_MEAS_SCO);
> if (ret)
> return ret;
>
> diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
> index 57ba0e85db91..4a501836d27a 100644
> --- a/drivers/iio/pressure/bmp280.h
> +++ b/drivers/iio/pressure/bmp280.h
> @@ -13,6 +13,9 @@
> #define BMP280_REG_PRESS_LSB 0xF8
> #define BMP280_REG_PRESS_MSB 0xF7
>
> +/* Helper mask to truncate excess 12 bits on pressure and temp readings */
> +#define BMP280_MEAS_TRIM_MASK GENMASK(31, 12)
> +
> #define BMP280_REG_CONFIG 0xF5
> #define BMP280_REG_CTRL_MEAS 0xF4
> #define BMP280_REG_STATUS 0xF3
> @@ -32,44 +35,43 @@
> #define BMP280_REG_COMP_PRESS_START 0x8E
> #define BMP280_COMP_PRESS_REG_COUNT 18
>
> -#define BMP280_FILTER_MASK (BIT(4) | BIT(3) | BIT(2))
> +#define BMP280_COMP_H5_MASK GENMASK(15, 4)
> +
> +#define BMP280_FILTER_MASK GENMASK(4, 2)
> #define BMP280_FILTER_OFF 0
> -#define BMP280_FILTER_2X BIT(2)
> -#define BMP280_FILTER_4X BIT(3)
> -#define BMP280_FILTER_8X (BIT(3) | BIT(2))
> -#define BMP280_FILTER_16X BIT(4)
> +#define BMP280_FILTER_2X 1
> +#define BMP280_FILTER_4X 2
> +#define BMP280_FILTER_8X 3
> +#define BMP280_FILTER_16X 4
>
> -#define BMP280_OSRS_HUMIDITY_MASK (BIT(2) | BIT(1) | BIT(0))
> -#define BMP280_OSRS_HUMIDITIY_X(osrs_h) ((osrs_h) << 0)
> +#define BMP280_OSRS_HUMIDITY_MASK GENMASK(2, 0)
> #define BMP280_OSRS_HUMIDITY_SKIP 0
> -#define BMP280_OSRS_HUMIDITY_1X BMP280_OSRS_HUMIDITIY_X(1)
> -#define BMP280_OSRS_HUMIDITY_2X BMP280_OSRS_HUMIDITIY_X(2)
> -#define BMP280_OSRS_HUMIDITY_4X BMP280_OSRS_HUMIDITIY_X(3)
> -#define BMP280_OSRS_HUMIDITY_8X BMP280_OSRS_HUMIDITIY_X(4)
> -#define BMP280_OSRS_HUMIDITY_16X BMP280_OSRS_HUMIDITIY_X(5)
> +#define BMP280_OSRS_HUMIDITY_1X 1
> +#define BMP280_OSRS_HUMIDITY_2X 2
> +#define BMP280_OSRS_HUMIDITY_4X 3
> +#define BMP280_OSRS_HUMIDITY_8X 4
> +#define BMP280_OSRS_HUMIDITY_16X 5
>
> -#define BMP280_OSRS_TEMP_MASK (BIT(7) | BIT(6) | BIT(5))
> +#define BMP280_OSRS_TEMP_MASK GENMASK(7, 5)
> #define BMP280_OSRS_TEMP_SKIP 0
> -#define BMP280_OSRS_TEMP_X(osrs_t) ((osrs_t) << 5)
> -#define BMP280_OSRS_TEMP_1X BMP280_OSRS_TEMP_X(1)
> -#define BMP280_OSRS_TEMP_2X BMP280_OSRS_TEMP_X(2)
> -#define BMP280_OSRS_TEMP_4X BMP280_OSRS_TEMP_X(3)
> -#define BMP280_OSRS_TEMP_8X BMP280_OSRS_TEMP_X(4)
> -#define BMP280_OSRS_TEMP_16X BMP280_OSRS_TEMP_X(5)
> -
> -#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2))
> +#define BMP280_OSRS_TEMP_1X 1
> +#define BMP280_OSRS_TEMP_2X 2
> +#define BMP280_OSRS_TEMP_4X 3
> +#define BMP280_OSRS_TEMP_8X 4
> +#define BMP280_OSRS_TEMP_16X 5
> +
> +#define BMP280_OSRS_PRESS_MASK GENMASK(4, 2)
> #define BMP280_OSRS_PRESS_SKIP 0
> -#define BMP280_OSRS_PRESS_X(osrs_p) ((osrs_p) << 2)
> -#define BMP280_OSRS_PRESS_1X BMP280_OSRS_PRESS_X(1)
> -#define BMP280_OSRS_PRESS_2X BMP280_OSRS_PRESS_X(2)
> -#define BMP280_OSRS_PRESS_4X BMP280_OSRS_PRESS_X(3)
> -#define BMP280_OSRS_PRESS_8X BMP280_OSRS_PRESS_X(4)
> -#define BMP280_OSRS_PRESS_16X BMP280_OSRS_PRESS_X(5)
> -
> -#define BMP280_MODE_MASK (BIT(1) | BIT(0))
> +#define BMP280_OSRS_PRESS_1X 1
> +#define BMP280_OSRS_PRESS_2X 2
> +#define BMP280_OSRS_PRESS_4X 3
> +#define BMP280_OSRS_PRESS_8X 4
> +#define BMP280_OSRS_PRESS_16X 5
> +
> +#define BMP280_MODE_MASK GENMASK(1, 0)
> #define BMP280_MODE_SLEEP 0
> -#define BMP280_MODE_FORCED BIT(0)
> -#define BMP280_MODE_NORMAL (BIT(1) | BIT(0))
> +#define BMP280_MODE_FORCED 1
> +#define BMP280_MODE_NORMAL 3
>
> /* BMP180 specific registers */
> #define BMP180_REG_OUT_XLSB 0xF8
> @@ -79,13 +81,15 @@
> #define BMP180_REG_CALIB_START 0xAA
> #define BMP180_REG_CALIB_COUNT 22
>
> +#define BMP180_MEAS_CTRL_MASK GENMASK(4, 0)
> +#define BMP180_MEAS_TEMP 0x0E
> +#define BMP180_MEAS_PRESS 0x14
> #define BMP180_MEAS_SCO BIT(5)
> -#define BMP180_MEAS_TEMP (0x0E | BMP180_MEAS_SCO)
> -#define BMP180_MEAS_PRESS_X(oss) ((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
> -#define BMP180_MEAS_PRESS_1X BMP180_MEAS_PRESS_X(0)
> -#define BMP180_MEAS_PRESS_2X BMP180_MEAS_PRESS_X(1)
> -#define BMP180_MEAS_PRESS_4X BMP180_MEAS_PRESS_X(2)
> -#define BMP180_MEAS_PRESS_8X BMP180_MEAS_PRESS_X(3)
> +#define BMP180_OSRS_PRESS_MASK GENMASK(7, 6)
> +#define BMP180_MEAS_PRESS_1X 0
> +#define BMP180_MEAS_PRESS_2X 1
> +#define BMP180_MEAS_PRESS_4X 2
> +#define BMP180_MEAS_PRESS_8X 3
>
> /* BMP180 and BMP280 common registers */
> #define BMP280_REG_CTRL_MEAS 0xF4

Next message: Juergen Gross: "Re: [PATCH] xen/xenbus: fix xenbus_setup_ring()"
Previous message: Christian Borntraeger: "Re: [PATCH v3 1/2] s390/vfio-ap: bypass unnecessary processing of AP resources"
In reply to: Angel Iglesias: "[PATCH v6 2/9] iio: pressure: bmp280: use FIELD_GET, FIELD_PREP and GENMASK"
Next in thread: Angel Iglesias: "[PATCH v6 3/9] iio: pressure: bmp280: Simplify bmp280 calibration data reading"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]