From 5517547bf44731621338c1a4047196a49c790719 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 27 May 2015 11:20:52 +0300 Subject: iio: magnetometer: correct a harmless off by one check The line before limits i to 0-3 so the existing code works fine but the check is still off by one and >= is intended instead of >. Signed-off-by: Dan Carpenter Reviewed-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index aa6e25d3bfc3..c71392cf1370 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -308,7 +308,7 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev, return ret; i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT; - if (i < 0 || i > ARRAY_SIZE(mmc35240_samp_freq)) + if (i < 0 || i >= ARRAY_SIZE(mmc35240_samp_freq)) return -EINVAL; *val = mmc35240_samp_freq[i]; -- cgit v1.2.3 From a52ffebcf19afea27588abe75828f9d300e08f3d Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Fri, 5 Jun 2015 14:03:10 +0300 Subject: iio: magnetometer: mmc35240: i2c device name should be lower case This is the standard convention for i2c device name and also this is the name used in some Intel platforms DT files. Fixes: abeb6b1e7b ("iio: magnetometer: Add support for MEMSIC MMC35240") Signed-off-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index c71392cf1370..d8cf5a6f9291 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -490,7 +490,7 @@ static const struct acpi_device_id mmc35240_acpi_match[] = { MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match); static const struct i2c_device_id mmc35240_id[] = { - {"MMC35240", 0}, + {"mmc35240", 0}, {} }; MODULE_DEVICE_TABLE(i2c, mmc35240_id); -- cgit v1.2.3 From bd35a214f56158d11e46c4a9d8436139f58e7099 Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Fri, 5 Jun 2015 14:03:11 +0300 Subject: iio: magnetometer: mmc35240: NULL terminate attribute array This avoid nasty crashes when registering the IIO device. Fixes: abeb6b1e7b ("iio: magnetometer: Add support for MEMSIC MMC35240") Signed-off-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index d8cf5a6f9291..78da0d15c8eb 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -125,6 +125,7 @@ static const struct iio_chan_spec mmc35240_channels[] = { static struct attribute *mmc35240_attributes[] = { &iio_const_attr_sampling_frequency_available.dev_attr.attr, + NULL }; static const struct attribute_group mmc35240_attribute_group = { -- cgit v1.2.3 From c2890547a035e019df646be5d56adc0ee1b0a327 Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Fri, 5 Jun 2015 14:03:12 +0300 Subject: iio: magnetometer: mmc35240: Fix broken processed value The current computation for fractional part of the magnetic field is broken. This patch fixes it by taking a different approach. We expose the raw reading in milli Gauss (to avoid rounding errors) with a scale of 0.001. Thus the final computation is done in userspace where floating point operation are more relaxed. Fixes: abeb6b1e7b ("iio: magnetometer: Add support for MEMSIC MMC35240") Signed-off-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 43 +++++++++++++++++++++++-------------- 1 file changed, 27 insertions(+), 16 deletions(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index 78da0d15c8eb..146ae6613537 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -113,8 +113,9 @@ static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 333 666"); .modified = 1, \ .channel2 = IIO_MOD_ ## _axis, \ .address = AXIS_ ## _axis, \ - .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ + BIT(IIO_CHAN_INFO_SCALE), \ } static const struct iio_chan_spec mmc35240_channels[] = { @@ -241,9 +242,19 @@ static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3]) 3 * sizeof(__le16)); } -static int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index, - __le16 buf[], - int *val, int *val2) +/** + * mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply + compensation for output value. + * + * @data: device private data + * @index: axis index for which we want the conversion + * @buf: raw data to be converted, 2 bytes in little endian format + * @val: compensated output reading (unit is milli gauss) + * + * Returns: 0 in case of success, -EINVAL when @index is not valid + */ +static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index, + __le16 buf[], int *val) { int raw_x, raw_y, raw_z; int sens_x, sens_y, sens_z; @@ -261,18 +272,15 @@ static int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index, switch (index) { case AXIS_X: - *val = (raw_x - nfo) / sens_x; - *val2 = ((raw_x - nfo) % sens_x) * 1000000; + *val = (raw_x - nfo) * 1000 / sens_x; break; case AXIS_Y: - *val = (raw_y - nfo) / sens_y - (raw_z - nfo) / sens_z; - *val2 = (((raw_y - nfo) % sens_y - (raw_z - nfo) % sens_z)) - * 1000000; + *val = (raw_y - nfo) * 1000 / sens_y - + (raw_z - nfo) * 1000 / sens_z; break; case AXIS_Z: - *val = (raw_y - nfo) / sens_y + (raw_z - nfo) / sens_z; - *val2 = (((raw_y - nfo) % sens_y + (raw_z - nfo) % sens_z)) - * 1000000; + *val = (raw_y - nfo) * 1000 / sens_y + + (raw_z - nfo) * 1000 / sens_z; break; default: return -EINVAL; @@ -290,16 +298,19 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev, __le16 buf[3]; switch (mask) { - case IIO_CHAN_INFO_PROCESSED: + case IIO_CHAN_INFO_RAW: mutex_lock(&data->mutex); ret = mmc35240_read_measurement(data, buf); mutex_unlock(&data->mutex); if (ret < 0) return ret; - ret = mmc35240_raw_to_gauss(data, chan->address, - buf, val, val2); + ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val); if (ret < 0) return ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = 1000; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SAMP_FREQ: mutex_lock(&data->mutex); -- cgit v1.2.3 From 787f55c4d1842e5fb037a81bca9bd9d9fdfd46fe Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Fri, 5 Jun 2015 14:03:13 +0300 Subject: iio: magnetometer: mmc35240: Use a smaller sleep value According to datasheet, Page 8, minimum wait time to complete measurement is 10ms. Adjusting this value will increase the userspace polling rate. Fixes: abeb6b1e7b ("iio: magnetometer: Add support for MEMSIC MMC35240") Signed-off-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index 146ae6613537..7fdf906b94c9 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -219,7 +219,8 @@ static int mmc35240_take_measurement(struct mmc35240_data *data) return ret; if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT) break; - msleep(20); + /* minimum wait time to complete measurement is 10 ms */ + usleep_range(10000, 11000); } if (tries < 0) { -- cgit v1.2.3 From 6b90da4b58b39a80f490479953aa2563c3c41a6d Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Fri, 5 Jun 2015 14:03:14 +0300 Subject: iio: magnetometer: mmc35240: Fix sensitivity on z-axis Datasheet says (Page 2) that typical value for sensitivity for 16 bits mode on Z-axis is 770. Anyhow, looking at the input driver provided by Memsic the value for MMC35240 is 1024. Also, testing shows that using 1024 for Z-axis senzitivity offers better results. Fixes: abeb6b1e7b ("iio: magnetometer: Add support for MEMSIC MMC35240") Signed-off-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index 7fdf906b94c9..b2ab58ea15f0 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -77,7 +77,7 @@ static const struct { } mmc35240_props_table[] = { /* 16 bits, 100Hz ODR */ { - {1024, 1024, 770}, + {1024, 1024, 1024}, 32768, }, /* 16 bits, 200Hz ODR */ -- cgit v1.2.3 From 4892688d7004c004765a51976087a8f51ce3586d Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Fri, 5 Jun 2015 14:03:15 +0300 Subject: iio: magnetometer: mmc35240: Add compensation for raw values This patch adds compensation formula to raw readings, borrowed from Memsic's input driver. Signed-off-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/mmc35240.c | 62 ++++++++++++++++++++++++++++++++++--- 1 file changed, 58 insertions(+), 4 deletions(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c index b2ab58ea15f0..7a2ea71c659a 100644 --- a/drivers/iio/magnetometer/mmc35240.c +++ b/drivers/iio/magnetometer/mmc35240.c @@ -58,6 +58,31 @@ #define MMC35240_WAIT_CHARGE_PUMP 50000 /* us */ #define MMC53240_WAIT_SET_RESET 1000 /* us */ +/* + * Memsic OTP process code piece is put here for reference: + * + * #define OTP_CONVERT(REG) ((float)((REG) >=32 ? (32 - (REG)) : (REG)) * 0.006 + * 1) For X axis, the COEFFICIENT is always 1. + * 2) For Y axis, the COEFFICIENT is as below: + * f_OTP_matrix[4] = OTP_CONVERT(((reg_data[1] & 0x03) << 4) | + * (reg_data[2] >> 4)) + 1.0; + * 3) For Z axis, the COEFFICIENT is as below: + * f_OTP_matrix[8] = (OTP_CONVERT(reg_data[3] & 0x3f) + 1) * 1.35; + * We implemented the OTP logic into driver. + */ + +/* scale = 1000 here for Y otp */ +#define MMC35240_OTP_CONVERT_Y(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 6) + +/* 0.6 * 1.35 = 0.81, scale 10000 for Z otp */ +#define MMC35240_OTP_CONVERT_Z(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 81) + +#define MMC35240_X_COEFF(x) (x) +#define MMC35240_Y_COEFF(y) (y + 1000) +#define MMC35240_Z_COEFF(z) (z + 13500) + +#define MMC35240_OTP_START_ADDR 0x1B + enum mmc35240_resolution { MMC35240_16_BITS_SLOW = 0, /* 100 Hz */ MMC35240_16_BITS_FAST, /* 200 Hz */ @@ -102,6 +127,10 @@ struct mmc35240_data { struct mutex mutex; struct regmap *regmap; enum mmc35240_resolution res; + + /* OTP compensation */ + int axis_coef[3]; + int axis_scale[3]; }; static const int mmc35240_samp_freq[] = {100, 200, 333, 666}; @@ -172,8 +201,9 @@ static int mmc35240_hw_set(struct mmc35240_data *data, bool set) static int mmc35240_init(struct mmc35240_data *data) { - int ret; + int ret, y_convert, z_convert; unsigned int reg_id; + u8 otp_data[6]; ret = regmap_read(data->regmap, MMC35240_REG_ID, ®_id); if (ret < 0) { @@ -197,9 +227,30 @@ static int mmc35240_init(struct mmc35240_data *data) return ret; /* set default sampling frequency */ - return regmap_update_bits(data->regmap, MMC35240_REG_CTRL1, - MMC35240_CTRL1_BW_MASK, - data->res << MMC35240_CTRL1_BW_SHIFT); + ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1, + MMC35240_CTRL1_BW_MASK, + data->res << MMC35240_CTRL1_BW_SHIFT); + if (ret < 0) + return ret; + + ret = regmap_bulk_read(data->regmap, MMC35240_OTP_START_ADDR, + (u8 *)otp_data, sizeof(otp_data)); + if (ret < 0) + return ret; + + y_convert = MMC35240_OTP_CONVERT_Y(((otp_data[1] & 0x03) << 4) | + (otp_data[2] >> 4)); + z_convert = MMC35240_OTP_CONVERT_Z(otp_data[3] & 0x3f); + + data->axis_coef[0] = MMC35240_X_COEFF(1); + data->axis_coef[1] = MMC35240_Y_COEFF(y_convert); + data->axis_coef[2] = MMC35240_Z_COEFF(z_convert); + + data->axis_scale[0] = 1; + data->axis_scale[1] = 1000; + data->axis_scale[2] = 10000; + + return 0; } static int mmc35240_take_measurement(struct mmc35240_data *data) @@ -286,6 +337,9 @@ static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index, default: return -EINVAL; } + /* apply OTP compensation */ + *val = (*val) * data->axis_coef[index] / data->axis_scale[index]; + return 0; } -- cgit v1.2.3