Adds a DMA-safe buffer to driver data struct to store raw data from sensor Updated calibration read functions to use DMA-safe buffers as well. In this case, as calibration data is only read at sensor initialization, the buffers are allocated with kmalloc and freed after being processed. Suggested-by: Jonathan Cameron <jic23@xxxxxxxxxx> Signed-off-by: Angel Iglesias <ang.iglesiasg@xxxxxxxxx> --- drivers/iio/pressure/bmp280-core.c | 164 ++++++++++++++++++----------- 1 file changed, 103 insertions(+), 61 deletions(-) diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c index 60fba199c7a0..9311eeec8473 100644 --- a/drivers/iio/pressure/bmp280-core.c +++ b/drivers/iio/pressure/bmp280-core.c @@ -29,6 +29,7 @@ #include <linux/completion.h> #include <linux/pm_runtime.h> #include <linux/random.h> +#include <asm/unaligned.h> #include "bmp280.h" @@ -36,7 +37,19 @@ * These enums are used for indexing into the array of calibration * coefficients for BMP180. */ -enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD }; +enum { + AC1 = 0, + AC2 = 2, + AC3 = 4, + AC4 = 6, + AC5 = 8, + AC6 = 10, + B1 = 12, + B2 = 14, + MB = 16, + MC = 18, + MD = 20, +}; struct bmp180_calib { s16 AC1; @@ -104,6 +117,12 @@ struct bmp280_data { * calculation. */ s32 t_fine; + + /* + * DMA (thus cache coherency maintenance) may require the + * transfer buffers to live in their own cache lines. + */ + u8 buf[3] __aligned(IIO_DMA_MINALIGN); }; struct bmp280_chip_info { @@ -135,8 +154,18 @@ struct bmp280_chip_info { * These enums are used for indexing into the array of compensation * parameters for BMP280. */ -enum { T1, T2, T3 }; -enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 }; +enum { T1 = 0, T2 = 2, T3 = 4 }; +enum { + P1 = 0, + P2 = 2, + P3 = 4, + P4 = 6, + P5 = 8, + P6 = 10, + P7 = 12, + P8 = 14, + P9 = 16, +}; static const struct iio_chan_spec bmp280_channels[] = { { @@ -159,51 +188,59 @@ static const struct iio_chan_spec bmp280_channels[] = { static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip) { int ret; + u8 *t_buf; + u8 *p_buf; unsigned int tmp; - __le16 l16; - __be16 b16; struct device *dev = data->dev; struct bmp280_calib *calib = &data->calib.bmp280; - __le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2]; - __le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2]; + t_buf = kmalloc(BMP280_COMP_TEMP_REG_COUNT, GFP_KERNEL); + if (!t_buf) + return -ENOMEM; /* Read temperature calibration values. */ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START, t_buf, BMP280_COMP_TEMP_REG_COUNT); if (ret < 0) { dev_err(data->dev, "failed to read temperature calibration parameters\n"); + kfree(t_buf); return ret; } /* Toss the temperature calibration data into the entropy pool */ add_device_randomness(t_buf, sizeof(t_buf)); - calib->T1 = le16_to_cpu(t_buf[T1]); - calib->T2 = le16_to_cpu(t_buf[T2]); - calib->T3 = le16_to_cpu(t_buf[T3]); + calib->T1 = get_unaligned_le16(&t_buf[T1]); + calib->T2 = get_unaligned_le16(&t_buf[T2]); + calib->T3 = get_unaligned_le16(&t_buf[T3]); + kfree(t_buf); + p_buf = kmalloc(BMP280_COMP_PRESS_REG_COUNT, GFP_KERNEL); + if (!p_buf) + return -ENOMEM; /* Read pressure calibration values. */ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START, p_buf, BMP280_COMP_PRESS_REG_COUNT); if (ret < 0) { dev_err(data->dev, "failed to read pressure calibration parameters\n"); + kfree(p_buf); return ret; } /* Toss the pressure calibration data into the entropy pool */ add_device_randomness(p_buf, sizeof(p_buf)); - calib->P1 = le16_to_cpu(p_buf[P1]); - calib->P2 = le16_to_cpu(p_buf[P2]); - calib->P3 = le16_to_cpu(p_buf[P3]); - calib->P4 = le16_to_cpu(p_buf[P4]); - calib->P5 = le16_to_cpu(p_buf[P5]); - calib->P6 = le16_to_cpu(p_buf[P6]); - calib->P7 = le16_to_cpu(p_buf[P7]); - calib->P8 = le16_to_cpu(p_buf[P8]); - calib->P9 = le16_to_cpu(p_buf[P9]); + calib->P1 = get_unaligned_le16(&p_buf[P1]); + calib->P2 = get_unaligned_le16(&p_buf[P2]); + calib->P3 = get_unaligned_le16(&p_buf[P3]); + calib->P4 = get_unaligned_le16(&p_buf[P4]); + calib->P5 = get_unaligned_le16(&p_buf[P5]); + calib->P6 = get_unaligned_le16(&p_buf[P6]); + calib->P7 = get_unaligned_le16(&p_buf[P7]); + calib->P8 = get_unaligned_le16(&p_buf[P8]); + calib->P9 = get_unaligned_le16(&p_buf[P9]); + kfree(p_buf); /* * Read humidity calibration values. @@ -222,12 +259,12 @@ static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip) } 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->buf, 2); if (ret < 0) { dev_err(dev, "failed to read H2 comp value\n"); return ret; } - calib->H2 = sign_extend32(le16_to_cpu(l16), 15); + calib->H2 = get_unaligned_le16(data->buf); ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp); if (ret < 0) { @@ -236,20 +273,20 @@ static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip) } 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->buf, 2); if (ret < 0) { dev_err(dev, "failed to read H4 comp value\n"); return ret; } - calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) | - (be16_to_cpu(b16) & 0xf), 11); + calib->H4 = sign_extend32(((get_unaligned_be16(data->buf) >> 4) & 0xff0) | + (get_unaligned_be16(data->buf) & 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->buf, 2); if (ret < 0) { 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(((get_unaligned_le16(data->buf) >> 4) & 0xfff), 11); ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp); if (ret < 0) { @@ -344,16 +381,15 @@ static int bmp280_read_temp(struct bmp280_data *data, int *val) { int ret; - __be32 tmp = 0; s32 adc_temp, comp_temp; - ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3); + ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, data->buf, 3); if (ret < 0) { dev_err(data->dev, "failed to read temperature\n"); return ret; } - adc_temp = be32_to_cpu(tmp) >> 12; + adc_temp = get_unaligned_be24(data->buf) >> 4; if (adc_temp == BMP280_TEMP_SKIPPED) { /* reading was skipped */ dev_err(data->dev, "reading temperature skipped\n"); @@ -377,7 +413,6 @@ static int bmp280_read_press(struct bmp280_data *data, int *val, int *val2) { int ret; - __be32 tmp = 0; s32 adc_press; u32 comp_press; @@ -386,13 +421,13 @@ static int bmp280_read_press(struct bmp280_data *data, if (ret < 0) 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, 3); if (ret < 0) { dev_err(data->dev, "failed to read pressure\n"); return ret; } - adc_press = be32_to_cpu(tmp) >> 12; + adc_press = get_unaligned_be24(data->buf) >> 4; if (adc_press == BMP280_PRESS_SKIPPED) { /* reading was skipped */ dev_err(data->dev, "reading pressure skipped\n"); @@ -408,7 +443,6 @@ static int bmp280_read_press(struct bmp280_data *data, static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2) { - __be16 tmp; int ret; s32 adc_humidity; u32 comp_humidity; @@ -418,13 +452,13 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2) if (ret < 0) 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->buf, 2); if (ret < 0) { dev_err(data->dev, "failed to read humidity\n"); return ret; } - adc_humidity = be16_to_cpu(tmp); + adc_humidity = get_unaligned_be16(data->buf); if (adc_humidity == BMP280_HUMIDITY_SKIPPED) { /* reading was skipped */ dev_err(data->dev, "reading humidity skipped\n"); @@ -755,56 +789,65 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas) static int bmp180_read_adc_temp(struct bmp280_data *data, int *val) { - __be16 tmp; int ret; ret = bmp180_measure(data, BMP180_MEAS_TEMP); if (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->buf, 2); if (ret) return ret; - *val = be16_to_cpu(tmp); + *val = get_unaligned_be16(data->buf); return 0; } static int bmp180_read_calib(struct bmp280_data *data, unsigned int chip) { + struct bmp180_calib *calib = &data->calib.bmp180; + u8 *buf; int ret; int i; - struct bmp180_calib *calib = &data->calib.bmp180; - __be16 buf[BMP180_REG_CALIB_COUNT / 2]; + + buf = kmalloc(BMP180_REG_CALIB_COUNT, GFP_KERNEL); + if (!buf) + return -ENOMEM; ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf, - sizeof(buf)); + BMP180_REG_CALIB_COUNT); - if (ret < 0) + if (ret < 0) { + kfree(buf); return ret; + } /* None of the words has the value 0 or 0xFFFF */ - for (i = 0; i < ARRAY_SIZE(buf); i++) { - if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff)) + for (i = 0; i < BMP180_REG_CALIB_COUNT; i += 2) { + if (get_unaligned_be16(&buf[i]) == cpu_to_be16(0) || + get_unaligned_be16(&buf[i]) == cpu_to_be16(0xffff)) { + kfree(buf); return -EIO; + } } /* Toss the calibration data into the entropy pool */ - add_device_randomness(buf, sizeof(buf)); - - calib->AC1 = be16_to_cpu(buf[AC1]); - calib->AC2 = be16_to_cpu(buf[AC2]); - calib->AC3 = be16_to_cpu(buf[AC3]); - calib->AC4 = be16_to_cpu(buf[AC4]); - calib->AC5 = be16_to_cpu(buf[AC5]); - calib->AC6 = be16_to_cpu(buf[AC6]); - calib->B1 = be16_to_cpu(buf[B1]); - calib->B2 = be16_to_cpu(buf[B2]); - calib->MB = be16_to_cpu(buf[MB]); - calib->MC = be16_to_cpu(buf[MC]); - calib->MD = be16_to_cpu(buf[MD]); - + add_device_randomness(buf, BMP180_REG_CALIB_COUNT); + + calib->AC1 = get_unaligned_be16(&buf[AC1]); + calib->AC2 = get_unaligned_be16(&buf[AC2]); + calib->AC3 = get_unaligned_be16(&buf[AC3]); + calib->AC4 = get_unaligned_be16(&buf[AC4]); + calib->AC5 = get_unaligned_be16(&buf[AC5]); + calib->AC6 = get_unaligned_be16(&buf[AC6]); + calib->B1 = get_unaligned_be16(&buf[B1]); + calib->B2 = get_unaligned_be16(&buf[B2]); + calib->MB = get_unaligned_be16(&buf[MB]); + calib->MC = get_unaligned_be16(&buf[MC]); + calib->MD = get_unaligned_be16(&buf[MD]); + + kfree(buf); return 0; } @@ -852,18 +895,17 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val) static int bmp180_read_adc_press(struct bmp280_data *data, int *val) { int ret; - __be32 tmp = 0; u8 oss = data->oversampling_press; ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss)); if (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, 3); if (ret) return ret; - *val = (be32_to_cpu(tmp) >> 8) >> (8 - oss); + *val = get_unaligned_be24(data->buf) >> (8 - oss); return 0; } -- 2.37.1