On Fri, 24 Jul 2020 16:31:59 +0530 Nishant Malpani <nish.malpani25@xxxxxxxxx> wrote: > ADXRS290 is a high performance MEMS pitch and roll (dual-axis in-plane) > angular rate sensor (gyroscope) designed for use in stabilization > applications. It also features an internal temperature sensor and > programmable high-pass and low-pass filters. > > Add support for ADXRS290 in direct-access mode for now. > > Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXRS290.pdf > Signed-off-by: Nishant Malpani <nish.malpani25@xxxxxxxxx> Looks pretty good to me. A few minor comments seeing as you'll be doing a v4 anyway to tidy up the bits Andy pointed out. I've pointed out the locking is probably in excess of what is needed, but I have no problem with you leaving it as it stands, in the interests of having less fragile code as you extend the driver futher. Thanks, Jonathan > --- > > Changes in v3: > - drop "Link" tag & extra line in commit message > - rename cut-off frequencies tables to > 'adxrs290_{lpf, hpf}_3db_freq_hz_table' to be more descriptive > - fix unsigned type errors > - add comments on how to scale raw angular velocity and temperature > values to appropriate units mentioned in the ABI > - re-order declarations in reversed spruce tree order > - remove 'indio_dev->dev.parent = &spi->dev' as the iio core handles it > during iio_device_alloc() > - use plain msleep() instead of the interruptible variant > - remove extra terminal comma > > Changes in v2: > - append copyright tag with author's info > - remove asm/unaligned.h header > - remove unnecessary comments about the registers' description > - rephrase comment on the usage of mutex_lock > - discard the usage of local tx, rx buffers; use DMA-safe buffers > provided by the SPI core instead > - utilize spi_w8r16 provided by the SPI core instead of writing a > wrapper over spi_sync_transfer which semantically does the same > - equip spi_write_then_read instead of plain spi_write since the > latter requires a DMA-safe buffer > - implement exact matching of filter 3db frequencies instead of > finding the "closest" match; rounding complexity is left to the > userspace > - include 'info_mask_shared_by_type_available' when initialising > iio_chan_spec instead of explicitly exposing attributes > signifying available filter 3db frequencies; with this we can > utilize read_avail core callback > --- > MAINTAINERS | 6 + > drivers/iio/gyro/Kconfig | 10 + > drivers/iio/gyro/Makefile | 1 + > drivers/iio/gyro/adxrs290.c | 446 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 463 insertions(+) > create mode 100644 drivers/iio/gyro/adxrs290.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 9077411c9890..71ae9b184179 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1098,6 +1098,12 @@ L: linux-media@xxxxxxxxxxxxxxx > S: Maintained > F: drivers/media/i2c/adv7842* > > +ANALOG DEVICES INC ADXRS290 DRIVER > +M: Nishant Malpani <nish.malpani25@xxxxxxxxx> > +L: linux-iio@xxxxxxxxxxxxxxx > +S: Supported > +F: drivers/iio/gyro/adxrs290.c > + > ANALOG DEVICES INC ASOC CODEC DRIVERS > M: Lars-Peter Clausen <lars@xxxxxxxxxx> > M: Nuno Sá <nuno.sa@xxxxxxxxxx> > diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig > index 6daeddf37f60..024a34139875 100644 > --- a/drivers/iio/gyro/Kconfig > +++ b/drivers/iio/gyro/Kconfig > @@ -41,6 +41,16 @@ config ADIS16260 > This driver can also be built as a module. If so, the module > will be called adis16260. > > +config ADXRS290 > + tristate "Analog Devices ADXRS290 Dual-Axis MEMS Gyroscope SPI driver" > + depends on SPI > + help > + Say yes here to build support for Analog Devices ADXRS290 programmable > + digital output gyroscope. > + > + This driver can also be built as a module. If so, the module will be > + called adxrs290. > + > config ADXRS450 > tristate "Analog Devices ADXRS450/3 Digital Output Gyroscope SPI driver" > depends on SPI > diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile > index 45cbd5dc644e..0319b397dc3f 100644 > --- a/drivers/iio/gyro/Makefile > +++ b/drivers/iio/gyro/Makefile > @@ -8,6 +8,7 @@ obj-$(CONFIG_ADIS16080) += adis16080.o > obj-$(CONFIG_ADIS16130) += adis16130.o > obj-$(CONFIG_ADIS16136) += adis16136.o > obj-$(CONFIG_ADIS16260) += adis16260.o > +obj-$(CONFIG_ADXRS290) += adxrs290.o > obj-$(CONFIG_ADXRS450) += adxrs450.o > obj-$(CONFIG_BMG160) += bmg160_core.o > obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o > diff --git a/drivers/iio/gyro/adxrs290.c b/drivers/iio/gyro/adxrs290.c > new file mode 100644 > index 000000000000..cff1af9211bc > --- /dev/null > +++ b/drivers/iio/gyro/adxrs290.c > @@ -0,0 +1,446 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * ADXRS290 SPI Gyroscope Driver > + * > + * Copyright (C) 2020 Nishant Malpani <nish.malpani25@xxxxxxxxx> > + * Copyright (C) 2020 Analog Devices, Inc. > + */ > + > +#include <linux/bitfield.h> > +#include <linux/device.h> > +#include <linux/delay.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/spi/spi.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +#define ADXRS290_ADI_ID 0xAD > +#define ADXRS290_MEMS_ID 0x1D > +#define ADXRS290_DEV_ID 0x92 > + > +#define ADXRS290_REG_ADI_ID 0x00 > +#define ADXRS290_REG_MEMS_ID 0x01 > +#define ADXRS290_REG_DEV_ID 0x02 > +#define ADXRS290_REG_REV_ID 0x03 > +#define ADXRS290_REG_SN0 0x04 /* Serial Number Registers, 4 bytes */ > +#define ADXRS290_REG_DATAX0 0x08 /* Roll Rate o/p Data Regs, 2 bytes */ > +#define ADXRS290_REG_DATAY0 0x0A /* Pitch Rate o/p Data Regs, 2 bytes */ > +#define ADXRS290_REG_TEMP0 0x0C > +#define ADXRS290_REG_POWER_CTL 0x10 > +#define ADXRS290_REG_FILTER 0x11 > +#define ADXRS290_REG_DATA_RDY 0x12 > + > +#define ADXRS290_READ BIT(7) > +#define ADXRS290_TSM BIT(0) > +#define ADXRS290_MEASUREMENT BIT(1) > +#define ADXRS290_SYNC GENMASK(1, 0) > +#define ADXRS290_LPF_MASK GENMASK(2, 0) > +#define ADXRS290_LPF(x) FIELD_PREP(ADXRS290_LPF_MASK, x) > +#define ADXRS290_HPF_MASK GENMASK(7, 4) > +#define ADXRS290_HPF(x) FIELD_PREP(ADXRS290_HPF_MASK, x) > + > +#define ADXRS290_READ_REG(reg) (ADXRS290_READ | (reg)) > + > +#define ADXRS290_MAX_TRANSITION_TIME_MS 100 > + > +enum adxrs290_mode { > + STANDBY, > + MEASUREMENT, > +}; > + > +struct adxrs290_state { > + struct spi_device *spi; > + /* Serialize reads and their subsequent processing */ > + struct mutex lock; > + enum adxrs290_mode mode; > + unsigned int lpf_3db_freq_idx; > + unsigned int hpf_3db_freq_idx; > +}; > + > +/* > + * Available cut-off frequencies of the low pass filter in Hz. > + * The integer part and fractional part are represented separately. > + */ > +static const int adxrs290_lpf_3db_freq_hz_table[][2] = { > + [0] = {480, 0}, > + [1] = {320, 0}, > + [2] = {160, 0}, > + [3] = {80, 0}, > + [4] = {56, 600000}, > + [5] = {40, 0}, > + [6] = {28, 300000}, > + [7] = {20, 0}, > +}; > + > +/* > + * Available cut-off frequencies of the high pass filter in Hz. > + * The integer part and fractional part are represented separately. > + */ > +static const int adxrs290_hpf_3db_freq_hz_table[][2] = { > + [0] = {0, 0}, > + [1] = {0, 11000}, > + [2] = {0, 22000}, > + [3] = {0, 44000}, > + [4] = {0, 87000}, > + [5] = {0, 175000}, > + [6] = {0, 350000}, > + [7] = {0, 700000}, > + [8] = {1, 400000}, > + [9] = {2, 800000}, > + [10] = {11, 300000}, > +}; > + > +static int adxrs290_get_rate_data(struct iio_dev *indio_dev, const u8 cmd, > + unsigned int *val) Why go through the effort of signed to unsigned to signed for val? > +{ > + struct adxrs290_state *st = iio_priv(indio_dev); > + int ret = 0; > + int temp; > + > + mutex_lock(&st->lock); > + temp = spi_w8r16(st->spi, cmd); > + if (temp < 0) { > + ret = temp; > + goto err_unlock; > + } > + > + *val = temp; > + > +err_unlock: > + mutex_unlock(&st->lock); > + return ret; > +} > + > +static int adxrs290_get_temp_data(struct iio_dev *indio_dev, unsigned int *val) > +{ > + const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_TEMP0); > + struct adxrs290_state *st = iio_priv(indio_dev); > + int ret = 0; > + int temp; > + > + mutex_lock(&st->lock); Just a quick note here. I don't think you actually need the lock (yet) as you aren't doing any read modify write cycles and in this particular case there is no local cached state to protect. However, I don't mind if you want to leave them as it may make things less fragile as you move forwards. > + temp = spi_w8r16(st->spi, cmd); > + if (temp < 0) { > + ret = temp; > + goto err_unlock; > + } > + > + /* extract lower 12 bits temperature reading */ > + *val = temp & 0x0FFF; > + > +err_unlock: > + mutex_unlock(&st->lock); > + return ret; > +} > + > +static int adxrs290_get_3db_freq(struct iio_dev *indio_dev, u8 *val, u8 *val2) > +{ > + const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_FILTER); > + struct adxrs290_state *st = iio_priv(indio_dev); > + int ret = 0; > + short temp; > + > + mutex_lock(&st->lock); > + temp = spi_w8r8(st->spi, cmd); > + if (temp < 0) { > + ret = temp; > + goto err_unlock; > + } > + > + *val = FIELD_GET(ADXRS290_LPF_MASK, temp); > + *val2 = FIELD_GET(ADXRS290_HPF_MASK, temp); > + > +err_unlock: > + mutex_unlock(&st->lock); > + return ret; > +} > + > +static int adxrs290_spi_write_reg(struct spi_device *spi, const u8 reg, > + const u8 val) > +{ > + u8 buf[2]; > + > + buf[0] = reg; > + buf[1] = val; > + > + return spi_write_then_read(spi, buf, ARRAY_SIZE(buf), NULL, 0); > +} > + > +static int adxrs290_find_match(const int (*freq_tbl)[2], const int n, > + const int val, const int val2) > +{ > + int i; > + > + for (i = 0; i < n; i++) { > + if (freq_tbl[i][0] == val && freq_tbl[i][1] == val2) > + return i; > + } > + > + return -EINVAL; > +} > + > +static int adxrs290_set_filter_freq(struct iio_dev *indio_dev, > + const unsigned int lpf_idx, > + const unsigned int hpf_idx) > +{ > + struct adxrs290_state *st = iio_priv(indio_dev); > + u8 val; > + > + val = ADXRS290_HPF(hpf_idx) | ADXRS290_LPF(lpf_idx); > + > + return adxrs290_spi_write_reg(st->spi, ADXRS290_REG_FILTER, val); > +} > + > +static int adxrs290_initial_setup(struct iio_dev *indio_dev) > +{ > + struct adxrs290_state *st = iio_priv(indio_dev); > + > + st->mode = MEASUREMENT; > + > + return adxrs290_spi_write_reg(st->spi, > + ADXRS290_REG_POWER_CTL, > + ADXRS290_MEASUREMENT | ADXRS290_TSM); > +} > + > +static int adxrs290_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, > + int *val2, > + long mask) > +{ > + struct adxrs290_state *st = iio_priv(indio_dev); > + unsigned int t; > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + switch (chan->type) { > + case IIO_ANGL_VEL: > + ret = adxrs290_get_rate_data(indio_dev, > + ADXRS290_READ_REG(chan->address), > + &t); > + if (ret < 0) > + return ret; > + *val = t; As mentioned above, you should be fine with using a signed value where you have &t. As we don't use *val in the error case, it's fine to write directly into it and avoid the need for the local variable t at all. > + return IIO_VAL_INT; > + case IIO_TEMP: > + ret = adxrs290_get_temp_data(indio_dev, &t); > + if (ret < 0) > + return ret; > + *val = t; > + return IIO_VAL_INT; > + default: > + return -EINVAL; > + } > + case IIO_CHAN_INFO_SCALE: > + switch (chan->type) { > + case IIO_ANGL_VEL: > + /* 1 LSB = 0.005 degrees/sec */ > + *val = 0; > + *val2 = 87266; > + return IIO_VAL_INT_PLUS_NANO; > + case IIO_TEMP: > + /* 1 LSB = 0.1 degrees Celsius */ > + *val = 100; > + return IIO_VAL_INT; > + default: > + return -EINVAL; > + } > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: > + switch (chan->type) { > + case IIO_ANGL_VEL: > + t = st->lpf_3db_freq_idx; > + *val = adxrs290_lpf_3db_freq_hz_table[t][0]; > + *val2 = adxrs290_lpf_3db_freq_hz_table[t][1]; > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > + case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY: > + switch (chan->type) { > + case IIO_ANGL_VEL: > + t = st->hpf_3db_freq_idx; > + *val = adxrs290_hpf_3db_freq_hz_table[t][0]; > + *val2 = adxrs290_hpf_3db_freq_hz_table[t][1]; > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > + } > + > + return -EINVAL; > +} > + > +static int adxrs290_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, > + int val2, > + long mask) > +{ > + struct adxrs290_state *st = iio_priv(indio_dev); > + int lpf_idx, hpf_idx; > + > + switch (mask) { > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: > + lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table, > + ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table), > + val, val2); > + if (lpf_idx < 0) > + return -EINVAL; > + /* caching the updated state of the low-pass filter */ > + st->lpf_3db_freq_idx = lpf_idx; > + /* retrieving the current state of the high-pass filter */ > + hpf_idx = st->hpf_3db_freq_idx; > + return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx); > + case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY: > + hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table, > + ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table), > + val, val2); > + if (hpf_idx < 0) > + return -EINVAL; > + /* caching the updated state of the high-pass filter */ > + st->hpf_3db_freq_idx = hpf_idx; > + /* retrieving the current state of the low-pass filter */ > + lpf_idx = st->lpf_3db_freq_idx; > + return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx); > + } > + > + return -EINVAL; > +} > + > +static int adxrs290_read_avail(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + const int **vals, int *type, int *length, > + long mask) > +{ > + switch (mask) { > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: > + *vals = (const int *)adxrs290_lpf_3db_freq_hz_table; > + *type = IIO_VAL_INT_PLUS_MICRO; > + /* Values are stored in a 2D matrix */ > + *length = ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table) * 2; > + > + return IIO_AVAIL_LIST; > + case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY: > + *vals = (const int *)adxrs290_hpf_3db_freq_hz_table; > + *type = IIO_VAL_INT_PLUS_MICRO; > + /* Values are stored in a 2D matrix */ > + *length = ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table) * 2; > + > + return IIO_AVAIL_LIST; > + default: > + return -EINVAL; > + } > +} > + > +#define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) { \ > + .type = IIO_ANGL_VEL, \ > + .address = reg, \ > + .modified = 1, \ > + .channel2 = IIO_MOD_##axis, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ > + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \ > + BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \ > + .info_mask_shared_by_type_available = \ > + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \ > + BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \ > +} > + > +static const struct iio_chan_spec adxrs290_channels[] = { > + ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAX0, X), > + ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAY0, Y), > + { > + .type = IIO_TEMP, > + .address = ADXRS290_REG_TEMP0, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + }, > +}; > + > +static const struct iio_info adxrs290_info = { > + .read_raw = &adxrs290_read_raw, > + .write_raw = &adxrs290_write_raw, > + .read_avail = &adxrs290_read_avail, > +}; > + > +static int adxrs290_probe(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev; > + struct adxrs290_state *st; > + u8 val, val2; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + st->spi = spi; > + spi_set_drvdata(spi, indio_dev); As things currently stand I don't think you ever use this. So drop it for now and reintroduce it when you need it (probably when you add power management support). > + > + indio_dev->name = "adxrs290"; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = adxrs290_channels; > + indio_dev->num_channels = ARRAY_SIZE(adxrs290_channels); > + indio_dev->info = &adxrs290_info; > + > + val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_ADI_ID)); > + if (val != ADXRS290_ADI_ID) { > + dev_err(&spi->dev, "Wrong ADI ID 0x%02x\n", val); > + return -ENODEV; > + } > + > + val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_MEMS_ID)); > + if (val != ADXRS290_MEMS_ID) { > + dev_err(&spi->dev, "Wrong MEMS ID 0x%02x\n", val); > + return -ENODEV; > + } > + > + val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_DEV_ID)); > + if (val != ADXRS290_DEV_ID) { > + dev_err(&spi->dev, "Wrong DEV ID 0x%02x\n", val); > + return -ENODEV; > + } > + > + /* default mode the gyroscope starts in */ > + st->mode = STANDBY; > + > + /* switch to measurement mode and switch on the temperature sensor */ > + ret = adxrs290_initial_setup(indio_dev); > + if (ret < 0) > + return ret; > + > + /* max transition time to measurement mode */ > + msleep(ADXRS290_MAX_TRANSITION_TIME_MS); > + > + ret = adxrs290_get_3db_freq(indio_dev, &val, &val2); > + if (ret < 0) > + return ret; > + > + st->lpf_3db_freq_idx = val; > + st->hpf_3db_freq_idx = val2; > + > + return devm_iio_device_register(&spi->dev, indio_dev); > +} > + > +static const struct of_device_id adxrs290_of_match[] = { > + { .compatible = "adi,adxrs290" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, adxrs290_of_match); > + > +static struct spi_driver adxrs290_driver = { > + .driver = { > + .name = "adxrs290", > + .of_match_table = adxrs290_of_match, > + }, > + .probe = adxrs290_probe, > +}; > +module_spi_driver(adxrs290_driver); > + > +MODULE_AUTHOR("Nishant Malpani <nish.malpani25@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Analog Devices ADXRS290 Gyroscope SPI driver"); > +MODULE_LICENSE("GPL");
