Skip to content

L
linux
Commit 327b5c05 authored by Angel Iglesias's avatar Angel Iglesias Committed by Jonathan Cameron
Browse files
Options

iio: pressure: bmp280: Fix alignment for DMA safety 

Adds DMA-safe buffers to driver data struct to store raw data from sensors

The multiple buffers used thorough the driver share the same memory
allocated as part of the device data instance. The union containing
the buffers is aligned to allow safe usage with DMA operations, such
as regmap bulk read calls.

Updated measurement and calibration reading functions to use the safe
DMA buffers.
Suggested-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarAngel Iglesias <ang.iglesiasg@gmail.com>
Link: https://lore.kernel.org/r/7919793f7f63224d5ce413c66d648029683c17ac.1663025017.git.ang.iglesiasg@gmail.comSigned-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent b00e805a
Hide whitespace changes
Inline Side-by-side
Showing with 76 additions and 59 deletions
drivers/iio/pressure/bmp280-core.c
View file @ 327b5c05
...@@ -38,6 +38,8 @@ ...@@ -38,6 +38,8 @@
#include <linux/pm_runtime.h> #include <linux/pm_runtime.h>
#include <linux/random.h> #include <linux/random.h>
#include <asm/unaligned.h>
#include "bmp280.h" #include "bmp280.h"
/* /*
...@@ -112,6 +114,21 @@ struct bmp280_data { ...@@ -112,6 +114,21 @@ struct bmp280_data {
* calculation. * calculation.
*/ */
s32 t_fine; s32 t_fine;
/*
* DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
*/
union {
/* Sensor data buffer */
u8 buf[3];
/* Calibration data buffers */
__le16 bmp280_cal_buf[BMP280_CONTIGUOUS_CALIB_REGS / 2];
__be16 bmp180_cal_buf[BMP180_REG_CALIB_COUNT / 2];
/* Miscellaneous, endianess-aware data buffers */
__le16 le16;
__be16 be16;
} __aligned(IIO_DMA_MINALIGN);
}; };
struct bmp280_chip_info { struct bmp280_chip_info {
...@@ -166,13 +183,12 @@ static const struct iio_chan_spec bmp280_channels[] = { ...@@ -166,13 +183,12 @@ static const struct iio_chan_spec bmp280_channels[] = {
static int bmp280_read_calib(struct bmp280_data *data) static int bmp280_read_calib(struct bmp280_data *data)
{ {
struct bmp280_calib *calib = &data->calib.bmp280; struct bmp280_calib *calib = &data->calib.bmp280;
__le16 c_buf[BMP280_CONTIGUOUS_CALIB_REGS / 2];
int ret; int ret;
/* Read temperature and pressure calibration values. */ /* Read temperature and pressure calibration values. */
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START, ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
c_buf, sizeof(c_buf)); data->bmp280_cal_buf, sizeof(data->bmp280_cal_buf));
if (ret < 0) { if (ret < 0) {
dev_err(data->dev, dev_err(data->dev,
"failed to read temperature and pressure calibration parameters\n"); "failed to read temperature and pressure calibration parameters\n");
...@@ -180,23 +196,23 @@ static int bmp280_read_calib(struct bmp280_data *data) ...@@ -180,23 +196,23 @@ static int bmp280_read_calib(struct bmp280_data *data)
} }
/* Toss the temperature and pressure calibration data into the entropy pool */ /* Toss the temperature and pressure calibration data into the entropy pool */
add_device_randomness(c_buf, sizeof(c_buf)); add_device_randomness(data->bmp280_cal_buf, sizeof(data->bmp280_cal_buf));
/* Parse temperature calibration values. */ /* Parse temperature calibration values. */
calib->T1 = le16_to_cpu(c_buf[T1]); calib->T1 = le16_to_cpu(data->bmp280_cal_buf[T1]);
calib->T2 = le16_to_cpu(c_buf[T2]); calib->T2 = le16_to_cpu(data->bmp280_cal_buf[T2]);
calib->T3 = le16_to_cpu(c_buf[T3]); calib->T3 = le16_to_cpu(data->bmp280_cal_buf[T3]);
/* Parse pressure calibration values. */ /* Parse pressure calibration values. */
calib->P1 = le16_to_cpu(c_buf[P1]); calib->P1 = le16_to_cpu(data->bmp280_cal_buf[P1]);
calib->P2 = le16_to_cpu(c_buf[P2]); calib->P2 = le16_to_cpu(data->bmp280_cal_buf[P2]);
calib->P3 = le16_to_cpu(c_buf[P3]); calib->P3 = le16_to_cpu(data->bmp280_cal_buf[P3]);
calib->P4 = le16_to_cpu(c_buf[P4]); calib->P4 = le16_to_cpu(data->bmp280_cal_buf[P4]);
calib->P5 = le16_to_cpu(c_buf[P5]); calib->P5 = le16_to_cpu(data->bmp280_cal_buf[P5]);
calib->P6 = le16_to_cpu(c_buf[P6]); calib->P6 = le16_to_cpu(data->bmp280_cal_buf[P6]);
calib->P7 = le16_to_cpu(c_buf[P7]); calib->P7 = le16_to_cpu(data->bmp280_cal_buf[P7]);
calib->P8 = le16_to_cpu(c_buf[P8]); calib->P8 = le16_to_cpu(data->bmp280_cal_buf[P8]);
calib->P9 = le16_to_cpu(c_buf[P9]); calib->P9 = le16_to_cpu(data->bmp280_cal_buf[P9]);
return 0; return 0;
} }
...@@ -206,8 +222,6 @@ static int bme280_read_calib(struct bmp280_data *data) ...@@ -206,8 +222,6 @@ static int bme280_read_calib(struct bmp280_data *data)
struct bmp280_calib *calib = &data->calib.bmp280; struct bmp280_calib *calib = &data->calib.bmp280;
struct device *dev = data->dev; struct device *dev = data->dev;
unsigned int tmp; unsigned int tmp;
__le16 l16;
__be16 b16;
int ret; int ret;
/* Load shared calibration params with bmp280 first */ /* Load shared calibration params with bmp280 first */
...@@ -232,12 +246,13 @@ static int bme280_read_calib(struct bmp280_data *data) ...@@ -232,12 +246,13 @@ static int bme280_read_calib(struct bmp280_data *data)
} }
calib->H1 = tmp; calib->H1 = tmp;
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &l16, 2); ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2,
&data->le16, sizeof(data->le16));
if (ret < 0) { if (ret < 0) {
dev_err(dev, "failed to read H2 comp value\n"); dev_err(dev, "failed to read H2 comp value\n");
return ret; return ret;
} }
calib->H2 = sign_extend32(le16_to_cpu(l16), 15); calib->H2 = sign_extend32(le16_to_cpu(data->le16), 15);
ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp); ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp);
if (ret < 0) { if (ret < 0) {
...@@ -246,20 +261,22 @@ static int bme280_read_calib(struct bmp280_data *data) ...@@ -246,20 +261,22 @@ static int bme280_read_calib(struct bmp280_data *data)
} }
calib->H3 = tmp; calib->H3 = tmp;
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &b16, 2); ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4,
&data->be16, sizeof(data->be16));
if (ret < 0) { if (ret < 0) {
dev_err(dev, "failed to read H4 comp value\n"); dev_err(dev, "failed to read H4 comp value\n");
return ret; return ret;
} }
calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) | calib->H4 = sign_extend32(((be16_to_cpu(data->be16) >> 4) & 0xff0) |
(be16_to_cpu(b16) & 0xf), 11); (be16_to_cpu(data->be16) & 0xf), 11);
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &l16, 2); ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5,
&data->le16, sizeof(data->le16));
if (ret < 0) { if (ret < 0) {
dev_err(dev, "failed to read H5 comp value\n"); dev_err(dev, "failed to read H5 comp value\n");
return ret; return ret;
} }
calib->H5 = sign_extend32(FIELD_GET(BMP280_COMP_H5_MASK, le16_to_cpu(l16)), 11); calib->H5 = sign_extend32(FIELD_GET(BMP280_COMP_H5_MASK, le16_to_cpu(data->le16)), 11);
ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp); ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
if (ret < 0) { if (ret < 0) {
...@@ -354,16 +371,16 @@ static int bmp280_read_temp(struct bmp280_data *data, ...@@ -354,16 +371,16 @@ static int bmp280_read_temp(struct bmp280_data *data,
int *val) int *val)
{ {
s32 adc_temp, comp_temp; s32 adc_temp, comp_temp;
__be32 tmp = 0;
int ret; int ret;
ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3); ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
data->buf, sizeof(data->buf));
if (ret < 0) { if (ret < 0) {
dev_err(data->dev, "failed to read temperature\n"); dev_err(data->dev, "failed to read temperature\n");
return ret; return ret;
} }
adc_temp = FIELD_GET(BMP280_MEAS_TRIM_MASK, be32_to_cpu(tmp)); adc_temp = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(data->buf));
if (adc_temp == BMP280_TEMP_SKIPPED) { if (adc_temp == BMP280_TEMP_SKIPPED) {
/* reading was skipped */ /* reading was skipped */
dev_err(data->dev, "reading temperature skipped\n"); dev_err(data->dev, "reading temperature skipped\n");
...@@ -387,7 +404,6 @@ static int bmp280_read_press(struct bmp280_data *data, ...@@ -387,7 +404,6 @@ static int bmp280_read_press(struct bmp280_data *data,
int *val, int *val2) int *val, int *val2)
{ {
u32 comp_press; u32 comp_press;
__be32 tmp = 0;
s32 adc_press; s32 adc_press;
int ret; int ret;
...@@ -396,13 +412,14 @@ static int bmp280_read_press(struct bmp280_data *data, ...@@ -396,13 +412,14 @@ static int bmp280_read_press(struct bmp280_data *data,
if (ret < 0) if (ret < 0)
return ret; return ret;
ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, &tmp, 3); ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
data->buf, sizeof(data->buf));
if (ret < 0) { if (ret < 0) {
dev_err(data->dev, "failed to read pressure\n"); dev_err(data->dev, "failed to read pressure\n");
return ret; return ret;
} }
adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, be32_to_cpu(tmp)); adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(data->buf));
if (adc_press == BMP280_PRESS_SKIPPED) { if (adc_press == BMP280_PRESS_SKIPPED) {
/* reading was skipped */ /* reading was skipped */
dev_err(data->dev, "reading pressure skipped\n"); dev_err(data->dev, "reading pressure skipped\n");
...@@ -420,7 +437,6 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2) ...@@ -420,7 +437,6 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
{ {
u32 comp_humidity; u32 comp_humidity;
s32 adc_humidity; s32 adc_humidity;
__be16 tmp;
int ret; int ret;
/* Read and compensate temperature so we get a reading of t_fine. */ /* Read and compensate temperature so we get a reading of t_fine. */
...@@ -428,13 +444,14 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2) ...@@ -428,13 +444,14 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
if (ret < 0) if (ret < 0)
return ret; return ret;
ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, &tmp, 2); ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB,
&data->be16, sizeof(data->be16));
if (ret < 0) { if (ret < 0) {
dev_err(data->dev, "failed to read humidity\n"); dev_err(data->dev, "failed to read humidity\n");
return ret; return ret;
} }
adc_humidity = be16_to_cpu(tmp); adc_humidity = be16_to_cpu(data->be16);
if (adc_humidity == BMP280_HUMIDITY_SKIPPED) { if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
/* reading was skipped */ /* reading was skipped */
dev_err(data->dev, "reading humidity skipped\n"); dev_err(data->dev, "reading humidity skipped\n");
...@@ -775,7 +792,6 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas) ...@@ -775,7 +792,6 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
static int bmp180_read_adc_temp(struct bmp280_data *data, int *val) static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
{ {
__be16 tmp;
int ret; int ret;
ret = bmp180_measure(data, ret = bmp180_measure(data,
...@@ -784,11 +800,12 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val) ...@@ -784,11 +800,12 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
if (ret) if (ret)
return ret; return ret;
ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2); ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
&data->be16, sizeof(data->be16));
if (ret) if (ret)
return ret; return ret;
*val = be16_to_cpu(tmp); *val = be16_to_cpu(data->be16);
return 0; return 0;
} }
...@@ -796,36 +813,36 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val) ...@@ -796,36 +813,36 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
static int bmp180_read_calib(struct bmp280_data *data) static int bmp180_read_calib(struct bmp280_data *data)
{ {
struct bmp180_calib *calib = &data->calib.bmp180; struct bmp180_calib *calib = &data->calib.bmp180;
__be16 buf[BMP180_REG_CALIB_COUNT / 2];
int ret; int ret;
int i; int i;
ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf, ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START,
sizeof(buf)); data->bmp180_cal_buf, sizeof(data->bmp180_cal_buf));
if (ret < 0) if (ret < 0)
return ret; return ret;
/* None of the words has the value 0 or 0xFFFF */ /* None of the words has the value 0 or 0xFFFF */
for (i = 0; i < ARRAY_SIZE(buf); i++) { for (i = 0; i < ARRAY_SIZE(data->bmp180_cal_buf); i++) {
if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff)) if (data->bmp180_cal_buf[i] == cpu_to_be16(0) ||
data->bmp180_cal_buf[i] == cpu_to_be16(0xffff))
return -EIO; return -EIO;
} }
/* Toss the calibration data into the entropy pool */ /* Toss the calibration data into the entropy pool */
add_device_randomness(buf, sizeof(buf)); add_device_randomness(data->bmp180_cal_buf, sizeof(data->bmp180_cal_buf));
calib->AC1 = be16_to_cpu(buf[AC1]); calib->AC1 = be16_to_cpu(data->bmp180_cal_buf[AC1]);
calib->AC2 = be16_to_cpu(buf[AC2]); calib->AC2 = be16_to_cpu(data->bmp180_cal_buf[AC2]);
calib->AC3 = be16_to_cpu(buf[AC3]); calib->AC3 = be16_to_cpu(data->bmp180_cal_buf[AC3]);
calib->AC4 = be16_to_cpu(buf[AC4]); calib->AC4 = be16_to_cpu(data->bmp180_cal_buf[AC4]);
calib->AC5 = be16_to_cpu(buf[AC5]); calib->AC5 = be16_to_cpu(data->bmp180_cal_buf[AC5]);
calib->AC6 = be16_to_cpu(buf[AC6]); calib->AC6 = be16_to_cpu(data->bmp180_cal_buf[AC6]);
calib->B1 = be16_to_cpu(buf[B1]); calib->B1 = be16_to_cpu(data->bmp180_cal_buf[B1]);
calib->B2 = be16_to_cpu(buf[B2]); calib->B2 = be16_to_cpu(data->bmp180_cal_buf[B2]);
calib->MB = be16_to_cpu(buf[MB]); calib->MB = be16_to_cpu(data->bmp180_cal_buf[MB]);
calib->MC = be16_to_cpu(buf[MC]); calib->MC = be16_to_cpu(data->bmp180_cal_buf[MC]);
calib->MD = be16_to_cpu(buf[MD]); calib->MD = be16_to_cpu(data->bmp180_cal_buf[MD]);
return 0; return 0;
} }
...@@ -874,7 +891,6 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val) ...@@ -874,7 +891,6 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val)
static int bmp180_read_adc_press(struct bmp280_data *data, int *val) static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
{ {
u8 oss = data->oversampling_press; u8 oss = data->oversampling_press;
__be32 tmp = 0;
int ret; int ret;
ret = bmp180_measure(data, ret = bmp180_measure(data,
...@@ -884,11 +900,12 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val) ...@@ -884,11 +900,12 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
if (ret) if (ret)
return ret; return ret;
ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 3); ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
data->buf, sizeof(data->buf));
if (ret) if (ret)
return ret; return ret;
*val = (be32_to_cpu(tmp) >> 8) >> (8 - oss); *val = get_unaligned_be24(data->buf) >> (8 - oss);
return 0; return 0;
} }
......
drivers/iio/pressure/bmp280.h
View file @ 327b5c05
...@@ -13,8 +13,8 @@ ...@@ -13,8 +13,8 @@
#define BMP280_REG_PRESS_LSB 0xF8 #define BMP280_REG_PRESS_LSB 0xF8
#define BMP280_REG_PRESS_MSB 0xF7 #define BMP280_REG_PRESS_MSB 0xF7
/* Helper mask to truncate excess 12 bits on pressure and temp readings */ /* Helper mask to truncate excess 4 bits on pressure and temp readings */
#define BMP280_MEAS_TRIM_MASK GENMASK(31, 12) #define BMP280_MEAS_TRIM_MASK GENMASK(24, 4)
#define BMP280_REG_CONFIG 0xF5 #define BMP280_REG_CONFIG 0xF5
#define BMP280_REG_CTRL_MEAS 0xF4 #define BMP280_REG_CTRL_MEAS 0xF4
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7