[PATCH v1 11/17] iio: chemical: bme680: Use bulk reads for calibration data
From: Vasileios Amoiridis
Date: Mon May 27 2024 - 14:40:45 EST
Calibration data are located in contiguous-ish registers
inside the chip. For that reason we can use bulk reads as is
done as well in the BME68x Sensor API [1].
The arrays that are used for reading the data out of the sensor
are located inside DMA safe buffer.
[1]: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L1769
Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
---
drivers/iio/chemical/bme680.h | 28 +--
drivers/iio/chemical/bme680_core.c | 283 ++++++++++-------------------
2 files changed, 101 insertions(+), 210 deletions(-)
diff --git a/drivers/iio/chemical/bme680.h b/drivers/iio/chemical/bme680.h
index 3133d624270a..5f602170a3af 100644
--- a/drivers/iio/chemical/bme680.h
+++ b/drivers/iio/chemical/bme680.h
@@ -39,10 +39,8 @@
#define BME680_HUM_REG_SHIFT_VAL 4
#define BME680_BIT_H1_DATA_MASK GENMASK(3, 0)
-#define BME680_REG_RES_HEAT_RANGE 0x02
#define BME680_RHRANGE_MASK GENMASK(5, 4)
#define BME680_REG_RES_HEAT_VAL 0x00
-#define BME680_REG_RANGE_SW_ERR 0x04
#define BME680_RSERROR_MASK GENMASK(7, 4)
#define BME680_REG_RES_HEAT_0 0x5A
#define BME680_REG_GAS_WAIT_0 0x64
@@ -58,31 +56,13 @@
/* Calibration Parameters */
#define BME680_T2_LSB_REG 0x8A
-#define BME680_T3_REG 0x8C
-#define BME680_P1_LSB_REG 0x8E
-#define BME680_P2_LSB_REG 0x90
-#define BME680_P3_REG 0x92
-#define BME680_P4_LSB_REG 0x94
-#define BME680_P5_LSB_REG 0x96
-#define BME680_P7_REG 0x98
-#define BME680_P6_REG 0x99
-#define BME680_P8_LSB_REG 0x9C
-#define BME680_P9_LSB_REG 0x9E
-#define BME680_P10_REG 0xA0
-#define BME680_H2_LSB_REG 0xE2
#define BME680_H2_MSB_REG 0xE1
-#define BME680_H1_MSB_REG 0xE3
-#define BME680_H1_LSB_REG 0xE2
-#define BME680_H3_REG 0xE4
-#define BME680_H4_REG 0xE5
-#define BME680_H5_REG 0xE6
-#define BME680_H6_REG 0xE7
-#define BME680_H7_REG 0xE8
-#define BME680_T1_LSB_REG 0xE9
-#define BME680_GH2_LSB_REG 0xEB
-#define BME680_GH1_REG 0xED
#define BME680_GH3_REG 0xEE
+#define BME680_CALIB_RANGE_1_LEN 23
+#define BME680_CALIB_RANGE_2_LEN 14
+#define BME680_CALIB_RANGE_3_LEN 5
+
extern const struct regmap_config bme680_regmap_config;
int bme680_core_probe(struct device *dev, struct regmap *regmap,
diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c
index 681f271f9b06..ed4cdb4d64af 100644
--- a/drivers/iio/chemical/bme680_core.c
+++ b/drivers/iio/chemical/bme680_core.c
@@ -19,8 +19,53 @@
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <asm/unaligned.h>
+
#include "bme680.h"
+/* 1st set of calibration data */
+enum {
+ /* Temperature calib indexes */
+ T2_LSB = 0,
+ T3 = 2,
+ /* Pressure calib indexes */
+ P1_LSB = 4,
+ P2_LSB = 6,
+ P3 = 8,
+ P4_LSB = 10,
+ P5_LSB = 12,
+ P7 = 14,
+ P6 = 15,
+ P8_LSB = 18,
+ P9_LSB = 20,
+ P10 = 22,
+};
+
+/* 2nd set of calibration data */
+enum {
+ /* Humidity calib indexes */
+ H2_MSB = 0,
+ H1_LSB = 1,
+ H3 = 3,
+ H4 = 4,
+ H5 = 5,
+ H6 = 6,
+ H7 = 7,
+ /* Stray T1 calib index */
+ T1_LSB = 8,
+ /* Gas heater calib indexes */
+ GH2_LSB = 10,
+ GH1 = 12,
+ GH3 = 13,
+};
+
+/* 3rd set of calibration data */
+enum {
+ RES_HEAT_VAL = 0,
+ RES_HEAT_RANGE = 2,
+ RANGE_SW_ERR = 4,
+};
+
struct bme680_calib {
u16 par_t1;
s16 par_t2;
@@ -64,6 +109,16 @@ struct bme680_data {
* and humidity compensation calculations.
*/
s32 t_fine;
+
+ /*
+ * DMA (thus cache coherency maintenance) may require the
+ * transfer buffers to live in their own cache lines.
+ */
+ union {
+ u8 bme680_cal_buf_1[BME680_CALIB_RANGE_1_LEN];
+ u8 bme680_cal_buf_2[BME680_CALIB_RANGE_2_LEN];
+ u8 bme680_cal_buf_3[BME680_CALIB_RANGE_3_LEN];
+ } __aligned(IIO_DMA_MINALIGN);
};
static const struct regmap_range bme680_volatile_ranges[] = {
@@ -112,217 +167,73 @@ static int bme680_read_calib(struct bme680_data *data,
struct bme680_calib *calib)
{
struct device *dev = regmap_get_device(data->regmap);
- unsigned int tmp, tmp_msb, tmp_lsb;
+ unsigned int tmp_msb, tmp_lsb;
int ret;
- __le16 buf;
-
- /* Temperature related coefficients */
- ret = regmap_bulk_read(data->regmap, BME680_T1_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_T1_LSB_REG\n");
- return ret;
- }
- calib->par_t1 = le16_to_cpu(buf);
ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG,
- &buf, sizeof(buf));
+ &data->bme680_cal_buf_1[0],
+ sizeof(data->bme680_cal_buf_1));
if (ret < 0) {
- dev_err(dev, "failed to read BME680_T2_LSB_REG\n");
+ dev_err(dev, "failed to read 1st set of calib data;\n");
return ret;
}
- calib->par_t2 = le16_to_cpu(buf);
- ret = regmap_read(data->regmap, BME680_T3_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_T3_REG\n");
- return ret;
- }
- calib->par_t3 = tmp;
+ calib->par_t2 = get_unaligned_le16(&data->bme680_cal_buf_1[T2_LSB]);
+ calib->par_t3 = data->bme680_cal_buf_1[T3];
+ calib->par_p1 = get_unaligned_le16(&data->bme680_cal_buf_1[P1_LSB]);
+ calib->par_p2 = get_unaligned_le16(&data->bme680_cal_buf_1[P2_LSB]);
+ calib->par_p3 = data->bme680_cal_buf_1[P3];
+ calib->par_p4 = get_unaligned_le16(&data->bme680_cal_buf_1[P4_LSB]);
+ calib->par_p5 = get_unaligned_le16(&data->bme680_cal_buf_1[P5_LSB]);
+ calib->par_p7 = data->bme680_cal_buf_1[P7];
+ calib->par_p6 = data->bme680_cal_buf_1[P6];
+ calib->par_p8 = get_unaligned_le16(&data->bme680_cal_buf_1[P8_LSB]);
+ calib->par_p9 = get_unaligned_le16(&data->bme680_cal_buf_1[P9_LSB]);
+ calib->par_p10 = data->bme680_cal_buf_1[P10];
- /* Pressure related coefficients */
- ret = regmap_bulk_read(data->regmap, BME680_P1_LSB_REG,
- &buf, sizeof(buf));
+ ret = regmap_bulk_read(data->regmap, BME680_H2_MSB_REG,
+ &data->bme680_cal_buf_2[0],
+ sizeof(data->bme680_cal_buf_2));
if (ret < 0) {
- dev_err(dev, "failed to read BME680_P1_LSB_REG\n");
+ dev_err(dev, "failed to read 2nd set of calib data;\n");
return ret;
}
- calib->par_p1 = le16_to_cpu(buf);
- ret = regmap_bulk_read(data->regmap, BME680_P2_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P2_LSB_REG\n");
- return ret;
- }
- calib->par_p2 = le16_to_cpu(buf);
-
- ret = regmap_read(data->regmap, BME680_P3_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P3_REG\n");
- return ret;
- }
- calib->par_p3 = tmp;
-
- ret = regmap_bulk_read(data->regmap, BME680_P4_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P4_LSB_REG\n");
- return ret;
- }
- calib->par_p4 = le16_to_cpu(buf);
-
- ret = regmap_bulk_read(data->regmap, BME680_P5_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P5_LSB_REG\n");
- return ret;
- }
- calib->par_p5 = le16_to_cpu(buf);
-
- ret = regmap_read(data->regmap, BME680_P6_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P6_REG\n");
- return ret;
- }
- calib->par_p6 = tmp;
-
- ret = regmap_read(data->regmap, BME680_P7_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P7_REG\n");
- return ret;
- }
- calib->par_p7 = tmp;
-
- ret = regmap_bulk_read(data->regmap, BME680_P8_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P8_LSB_REG\n");
- return ret;
- }
- calib->par_p8 = le16_to_cpu(buf);
-
- ret = regmap_bulk_read(data->regmap, BME680_P9_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P9_LSB_REG\n");
- return ret;
- }
- calib->par_p9 = le16_to_cpu(buf);
-
- ret = regmap_read(data->regmap, BME680_P10_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_P10_REG\n");
- return ret;
- }
- calib->par_p10 = tmp;
-
- /* Humidity related coefficients */
- ret = regmap_read(data->regmap, BME680_H1_MSB_REG, &tmp_msb);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H1_MSB_REG\n");
- return ret;
- }
- ret = regmap_read(data->regmap, BME680_H1_LSB_REG, &tmp_lsb);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H1_LSB_REG\n");
- return ret;
- }
+ tmp_lsb = data->bme680_cal_buf_2[H1_LSB];
+ tmp_msb = data->bme680_cal_buf_2[H1_LSB + 1];
calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) |
(tmp_lsb & BME680_BIT_H1_DATA_MASK);
- ret = regmap_read(data->regmap, BME680_H2_MSB_REG, &tmp_msb);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H2_MSB_REG\n");
- return ret;
- }
- ret = regmap_read(data->regmap, BME680_H2_LSB_REG, &tmp_lsb);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H2_LSB_REG\n");
- return ret;
- }
+ tmp_msb = data->bme680_cal_buf_2[H2_MSB];
+ tmp_lsb = data->bme680_cal_buf_2[H2_MSB + 1];
calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) |
(tmp_lsb >> BME680_HUM_REG_SHIFT_VAL);
- ret = regmap_read(data->regmap, BME680_H3_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H3_REG\n");
- return ret;
- }
- calib->par_h3 = tmp;
-
- ret = regmap_read(data->regmap, BME680_H4_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H4_REG\n");
- return ret;
- }
- calib->par_h4 = tmp;
-
- ret = regmap_read(data->regmap, BME680_H5_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H5_REG\n");
- return ret;
- }
- calib->par_h5 = tmp;
-
- ret = regmap_read(data->regmap, BME680_H6_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_H6_REG\n");
- return ret;
- }
- calib->par_h6 = tmp;
+ calib->par_h3 = data->bme680_cal_buf_2[H3];
+ calib->par_h4 = data->bme680_cal_buf_2[H4];
+ calib->par_h5 = data->bme680_cal_buf_2[H5];
+ calib->par_h6 = data->bme680_cal_buf_2[H6];
+ calib->par_h7 = data->bme680_cal_buf_2[H7];
+ calib->par_t1 = get_unaligned_le16(&data->bme680_cal_buf_2[T1_LSB]);
+ calib->par_gh2 = get_unaligned_le16(&data->bme680_cal_buf_2[GH2_LSB]);
+ calib->par_gh1 = data->bme680_cal_buf_2[GH1];
+ calib->par_gh3 = data->bme680_cal_buf_2[GH3];
- ret = regmap_read(data->regmap, BME680_H7_REG, &tmp);
+ ret = regmap_bulk_read(data->regmap, BME680_REG_RES_HEAT_VAL,
+ &data->bme680_cal_buf_3[0],
+ sizeof(data->bme680_cal_buf_3));
if (ret < 0) {
- dev_err(dev, "failed to read BME680_H7_REG\n");
+ dev_err(dev, "failed to read 3rd set of calib data;\n");
return ret;
}
- calib->par_h7 = tmp;
- /* Gas heater related coefficients */
- ret = regmap_read(data->regmap, BME680_GH1_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_GH1_REG\n");
- return ret;
- }
- calib->par_gh1 = tmp;
+ calib->res_heat_val = data->bme680_cal_buf_3[RES_HEAT_VAL];
- ret = regmap_bulk_read(data->regmap, BME680_GH2_LSB_REG,
- &buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_GH2_LSB_REG\n");
- return ret;
- }
- calib->par_gh2 = le16_to_cpu(buf);
+ calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK,
+ data->bme680_cal_buf_3[RES_HEAT_RANGE]);
- ret = regmap_read(data->regmap, BME680_GH3_REG, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read BME680_GH3_REG\n");
- return ret;
- }
- calib->par_gh3 = tmp;
-
- /* Other coefficients */
- ret = regmap_read(data->regmap, BME680_REG_RES_HEAT_RANGE, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read resistance heat range\n");
- return ret;
- }
- calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK, tmp);
-
- ret = regmap_read(data->regmap, BME680_REG_RES_HEAT_VAL, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read resistance heat value\n");
- return ret;
- }
- calib->res_heat_val = tmp;
-
- ret = regmap_read(data->regmap, BME680_REG_RANGE_SW_ERR, &tmp);
- if (ret < 0) {
- dev_err(dev, "failed to read range software error\n");
- return ret;
- }
- calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK, tmp);
+ calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK,
+ data->bme680_cal_buf_3[RANGE_SW_ERR]);
return 0;
}
--
2.25.1