On Fri, 26 Aug 2016, Linus Walleij wrote:
comments from a quick read below
> This adds a new driver for the Invensense MPU-3050 gyroscope.
> This driver is based on information from the rough input driver
> in drivers/input/misc/mpu3050.c and the scratch misc driver
> posted by Nathan Royer in 2011. Some years have passed but this
> is finally a fully-fledged driver for this gyroscope. It was
> developed and tested on the Qualcomm APQ8060 Dragonboard.
>
> The driver supports both raw and buffered input. It also
> supports the internal trigger mechanism by registering a trigger
> that can fire in response to the internal sample engine of the
> component. In addition to reading out the gyroscope sensor
> values, the driver also supports reading the temperature from
> the sensor.
>
> The driver currently only supports I2C but the MPU-3050 can
> also be used from SPI, so the I2C portions are split in their
> own file and we just use regmap to access all registers, so
> it will be trivial to plug in SPI support if/when someone has
> a system requiring this.
>
> To conserve power, the driver utilizes the runtime PM
> framework and will put the sensor in off mode and disable the
> regulators when unused, after a timeout of 10 seconds.
>
> The fullscale can be set for the sensor to 250, 500, 1000 or
> 2000 deg/s. This corresponds to scale values of rougly 0.000122,
> 0.000275, 0.000512 or 0.001068. By writing such values (or close
> to these) into "in_anglevel_scale", the corresponding fullscale
> can be chosen. It will default to 2000 deg/s (~35 rad/s).
>
> The gyro component can have DC offsets on all axes. These can be
> compensated using the standard sysfs ABI property
> "in_anglevel_[xyz]_calibbias". This is in positive/negative
> values of the raw values, so a suitable calibration bias can be
> determined by userspace by reading the "in_anglevel_[xyz]_raw"
> for a few iterations while holding the sensor still, create an
> average integer, and writing the negative inverse of that into
> "in_anglevel_[xyz]_calibbias". After this the hardware will
> automatically subtract the bias, also when using buffered
> readings.
>
> Since the MPU-3050 has an outgoing I2C port it needs to act as
> an I2C mux. This means that the device is switching I2C traffic
> to devices beyond it. On my system this is the only way to reach
> the accelerometer. The "sensor fusion" ability of the MPU-3050
> to directly talk to the device on the outgoing I2C port is
> currently not used by the driver, but it has code to allow I2C
> traffic to pass through so that the Linux kernel can reach the
> device on the other side with a kernel driver.
>
> Example usage with the native trigger:
>
> $ generic_buffer -a -c10 -n mpu3050
> iio device number being used is 0
> iio trigger number being used is 0
> No channels are enabled, enabling all channels
> Enabling: in_anglvel_z_en
> Enabling: in_timestamp_en
> Enabling: in_anglvel_y_en
> Enabling: in_temp_en
> Enabling: in_anglvel_x_en
> /sys/bus/iio/devices/iio:device0 mpu3050-dev0
> 29607.142578 -0.117493 0.074768 0.012817 180788797150
> 29639.285156 -0.117493 0.076904 0.013885 180888982335
> 29696.427734 -0.116425 0.076904 0.012817 180989178039
> 29742.857422 -0.117493 0.076904 0.012817 181089377742
> 29764.285156 -0.116425 0.077972 0.012817 181189574187
> 29860.714844 -0.115356 0.076904 0.012817 181289772705
> 29864.285156 -0.117493 0.076904 0.012817 181389971520
> 29910.714844 -0.115356 0.076904 0.013885 181490170483
> 29917.857422 -0.116425 0.076904 0.011749 181590369742
> 29975.000000 -0.116425 0.076904 0.012817 181690567075
> Disabling: in_anglvel_z_en
> Disabling: in_timestamp_en
> Disabling: in_anglvel_y_en
> Disabling: in_temp_en
> Disabling: in_anglvel_x_en
>
> The first column is the temperature in millidegrees, then the x,y,z
> axes in succession followed by the timestamp. Also tested successfully
> using the HRTimer trigger.
>
> Cc: Nick Vaccaro <nvaccaro@xxxxxxxxxx>
> Cc: Ge Gao <ggao@xxxxxxxxxxxxxx>
> Cc: Anna Si <asi@xxxxxxxxxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
> Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
> Cc: Gregor Boirie <gregor.boirie@xxxxxxxxxx>
> Cc: Peter Rosin <peda@xxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> ChangeLog v2->v3:
> - Use the new I2C_MUX_GATE flag in the I2C transport driver.
> ChangeLog v1->v2:
> - Bake mpu3050-core.c and mpu3050-i2c.c into a single object
> and a single module. Preserve all abstraction needed to simply
> split them and create an SPI transport, but for now leave it
> as a single object that does I2C only.
> - Rename mpu3050.c to mpu3050-core.c to be able to bake the two
> objects into mpu3050.o
> - Put in a verbose comment explaining when we fall through on the
> FIFO and just start reading raw values from the sensor instead.
> - Get and set the sampling frequency (used when using the internal
> hardware trigger) using the raw read/write callbacks instead of
> a custom sysfs file for the whole device. Use the *shared_by_all
> attribute to set the frequency for the whole device (as all axes,
> temperature and timestamp will be affected).
> - Move the register and bit defines into the core driver from the
> mpu3050.h driver.
> - Speling errors in commit message and elsewhere.
>
> It is still unclear how to migrate users of the old input driver
> to this driver. I want to merge this "clean" IIO driver first as
> a base to extend it with input capabilities and then move over
> any remaining users of the Input driver.
>
> The CCs in this mail is just some random people that worked on
> this or other Invensense products in the upstream kernel or in
> Google's gits.
>
> I suspect some of the stuff I've done here should be carried
> over to the MPU-6050 driver in drivers/iio/imu/inv_mpu6050/*
> ---
> MAINTAINERS | 7 +
> drivers/iio/gyro/Kconfig | 17 +
> drivers/iio/gyro/Makefile | 5 +
> drivers/iio/gyro/mpu3050-core.c | 1327 +++++++++++++++++++++++++++++++++++++++
> drivers/iio/gyro/mpu3050-i2c.c | 124 ++++
> drivers/iio/gyro/mpu3050.h | 96 +++
> 6 files changed, 1576 insertions(+)
> create mode 100644 drivers/iio/gyro/mpu3050-core.c
> create mode 100644 drivers/iio/gyro/mpu3050-i2c.c
> create mode 100644 drivers/iio/gyro/mpu3050.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 353bfe6bbaca..a9133866cecf 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6294,6 +6294,13 @@ S: Maintained
> F: arch/x86/include/asm/pmc_core.h
> F: drivers/platform/x86/intel_pmc_core*
>
> +INVENSENSE MPU-3050 GYROSCOPE DRIVER
> +M: Linus Walleij <linus.walleij@xxxxxxxxxx>
> +L: linux-iio@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/iio/gyro/mpu3050*
> +F: Documentation/devicetree/bindings/iio/gyroscope/inv,mpu3050.txt
> +
> IOC3 ETHERNET DRIVER
> M: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> L: linux-mips@xxxxxxxxxxxxxx
> diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
> index 205a84420ae9..107b5efd4178 100644
> --- a/drivers/iio/gyro/Kconfig
> +++ b/drivers/iio/gyro/Kconfig
> @@ -84,6 +84,23 @@ config HID_SENSOR_GYRO_3D
> Say yes here to build support for the HID SENSOR
> Gyroscope 3D.
>
> +config MPU3050
> + tristate
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + select REGMAP
> +
> +config MPU3050_I2C
> + tristate "Invensense MPU3050 devices on I2C"
> + depends on !(INPUT_MPU3050=y || INPUT_MPU3050=m)
> + select MPU3050
> + select REGMAP_I2C
> + select I2C_MUX
> + help
> + This driver supports the Invensense MPU3050 gyroscope over I2C.
> + This driver can be built as a module. The module will be called
> + inv-mpu3050-i2c.
> +
> config IIO_ST_GYRO_3AXIS
> tristate "STMicroelectronics gyroscopes 3-Axis Driver"
> depends on (I2C || SPI_MASTER) && SYSFS
> diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
> index f866a4be0667..f0e149a606b0 100644
> --- a/drivers/iio/gyro/Makefile
> +++ b/drivers/iio/gyro/Makefile
> @@ -14,6 +14,11 @@ obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o
>
> obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
>
> +# Currently this is rolled into one module, split it if
> +# we ever create a separate SPI interface for MPU-3050
> +obj-$(CONFIG_MPU3050) += mpu3050.o
> +mpu3050-objs := mpu3050-core.o mpu3050-i2c.o
> +
> itg3200-y := itg3200_core.o
> itg3200-$(CONFIG_IIO_BUFFER) += itg3200_buffer.o
> obj-$(CONFIG_ITG3200) += itg3200.o
> diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
> new file mode 100644
> index 000000000000..a5ca6169c68c
> --- /dev/null
> +++ b/drivers/iio/gyro/mpu3050-core.c
> @@ -0,0 +1,1327 @@
> +/*
> + * MPU3050 gyroscope driver
> + *
> + * Copyright (C) 2016 Linaro Ltd.
> + * Author: Linus Walleij <linus.walleij@xxxxxxxxxx>
> + *
> + * Based on the input subsystem driver, Copyright (C) 2011 Wistron Co.Ltd
> + * Joseph Lai <joseph_lai@xxxxxxxxxxx> and trimmed down by
> + * Alan Cox <alan@xxxxxxxxxxxxxxx> in turn based on bma023.c.
> + * Device behaviour based on a misc driver posted by Nathan Royer in 2011.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/random.h>
> +#include <linux/slab.h>
> +
> +#include "mpu3050.h"
> +
> +#define MPU3050_CHIP_ID 0x69
> +
> +/*
> + * Register map: anything suffixed *_H is a big-endian high byte and always
> + * followed by the corresponding low byte (*_L) even though these are not
> + * explicitly included in the register definitions.
> + */
> +#define MPU3050_CHIP_ID_REG 0x00
> +#define MPU3050_PRODUCT_ID_REG 0x01
> +#define MPU3050_XG_OFFS_TC 0x05
> +#define MPU3050_YG_OFFS_TC 0x08
> +#define MPU3050_ZG_OFFS_TC 0x0B
> +#define MPU3050_X_OFFS_USRH 0x0C
should probably end in _H to match the comment above
> +#define MPU3050_Y_OFFS_USRH 0x0E
> +#define MPU3050_Z_OFFS_USRH 0x10
> +#define MPU3050_FIFO_EN 0x12
> +#define MPU3050_AUX_VDDIO 0x13
> +#define MPU3050_SLV_ADDR 0x14
> +#define MPU3050_SMPLRT_DIV 0x15
> +#define MPU3050_DLPF_FS_SYNC 0x16
> +#define MPU3050_INT_CFG 0x17
> +#define MPU3050_AUX_ADDR 0x18
> +#define MPU3050_INT_STATUS 0x1A
> +#define MPU3050_TEMP_H 0x1B
> +#define MPU3050_XOUT_H 0x1D
> +#define MPU3050_YOUT_H 0x1F
> +#define MPU3050_ZOUT_H 0x21
> +#define MPU3050_DMP_CFG1 0x35
> +#define MPU3050_DMP_CFG2 0x36
> +#define MPU3050_BANK_SEL 0x37
> +#define MPU3050_MEM_START_ADDR 0x38
> +#define MPU3050_MEM_R_W 0x39
> +#define MPU3050_FIFO_COUNT_H 0x3A
> +#define MPU3050_FIFO_R 0x3C
> +#define MPU3050_USR_CTRL 0x3D
> +#define MPU3050_PWR_MGM 0x3E
> +
> +/* MPU memory bank read options */
> +#define MPU3050_MEM_PRFTCH BIT(5)
> +#define MPU3050_MEM_USER_BANK BIT(4)
> +/* Bits 8-11 select memory bank */
> +#define MPU3050_MEM_RAM_BANK_0 0
> +#define MPU3050_MEM_RAM_BANK_1 1
> +#define MPU3050_MEM_RAM_BANK_2 2
> +#define MPU3050_MEM_RAM_BANK_3 3
> +#define MPU3050_MEM_OTP_BANK_0 4
> +
> +#define MPU3050_AXIS_REGS(axis) (MPU3050_XOUT_H + (axis * 2))
> +
> +/* Register bits */
> +
> +/* FIFO Enable */
> +#define MPU3050_FIFO_EN_FOOTER BIT(0)
> +#define MPU3050_FIFO_EN_AUX_ZOUT BIT(1)
> +#define MPU3050_FIFO_EN_AUX_YOUT BIT(2)
> +#define MPU3050_FIFO_EN_AUX_XOUT BIT(3)
> +#define MPU3050_FIFO_EN_GYRO_ZOUT BIT(4)
> +#define MPU3050_FIFO_EN_GYRO_YOUT BIT(5)
> +#define MPU3050_FIFO_EN_GYRO_XOUT BIT(6)
> +#define MPU3050_FIFO_EN_TEMP_OUT BIT(7)
> +
> +/*
> + * Digital Low Pass filter (DLPF)
> + * Full Scale (FS)
> + * and Synchronization
> + */
> +#define MPU3050_EXT_SYNC_NONE 0x00
> +#define MPU3050_EXT_SYNC_TEMP 0x20
> +#define MPU3050_EXT_SYNC_GYROX 0x40
> +#define MPU3050_EXT_SYNC_GYROY 0x60
> +#define MPU3050_EXT_SYNC_GYROZ 0x80
> +#define MPU3050_EXT_SYNC_ACCELX 0xA0
> +#define MPU3050_EXT_SYNC_ACCELY 0xC0
> +#define MPU3050_EXT_SYNC_ACCELZ 0xE0
> +#define MPU3050_EXT_SYNC_MASK 0xE0
> +#define MPU3050_EXT_SYNC_SHIFT 5
> +
> +#define MPU3050_FS_250DPS 0x00
> +#define MPU3050_FS_500DPS 0x08
> +#define MPU3050_FS_1000DPS 0x10
> +#define MPU3050_FS_2000DPS 0x18
> +#define MPU3050_FS_MASK 0x18
> +#define MPU3050_FS_SHIFT 3
> +
> +#define MPU3050_DLPF_CFG_256HZ_NOLPF2 0x00
> +#define MPU3050_DLPF_CFG_188HZ 0x01
> +#define MPU3050_DLPF_CFG_98HZ 0x02
> +#define MPU3050_DLPF_CFG_42HZ 0x03
> +#define MPU3050_DLPF_CFG_20HZ 0x04
> +#define MPU3050_DLPF_CFG_10HZ 0x05
> +#define MPU3050_DLPF_CFG_5HZ 0x06
> +#define MPU3050_DLPF_CFG_2100HZ_NOLPF 0x07
> +#define MPU3050_DLPF_CFG_MASK 0x07
> +#define MPU3050_DLPF_CFG_SHIFT 0
> +
> +/* Interrupt config */
> +#define MPU3050_INT_RAW_RDY_EN BIT(0)
> +#define MPU3050_INT_DMP_DONE_EN BIT(1)
> +#define MPU3050_INT_MPU_RDY_EN BIT(2)
> +#define MPU3050_INT_ANYRD_2CLEAR BIT(4)
> +#define MPU3050_INT_LATCH_EN BIT(5)
> +#define MPU3050_INT_OPEN BIT(6)
> +#define MPU3050_INT_ACTL BIT(7)
> +/* Interrupt status */
> +#define MPU3050_INT_STATUS_RAW_RDY BIT(0)
> +#define MPU3050_INT_STATUS_DMP_DONE BIT(1)
> +#define MPU3050_INT_STATUS_MPU_RDY BIT(2)
> +#define MPU3050_INT_STATUS_FIFO_OVFLW BIT(7)
> +/* USR_CTRL */
> +#define MPU3050_USR_CTRL_FIFO_EN BIT(6)
> +#define MPU3050_USR_CTRL_AUX_IF_EN BIT(5)
> +#define MPU3050_USR_CTRL_AUX_IF_RST BIT(3)
> +#define MPU3050_USR_CTRL_FIFO_RST BIT(1)
> +#define MPU3050_USR_CTRL_GYRO_RST BIT(0)
> +/* PWR_MGM */
> +#define MPU3050_PWR_MGM_PLL_X 0x01
> +#define MPU3050_PWR_MGM_PLL_Y 0x02
> +#define MPU3050_PWR_MGM_PLL_Z 0x03
> +#define MPU3050_PWR_MGM_CLKSEL_MASK 0x07
> +#define MPU3050_PWR_MGM_STBY_ZG BIT(3)
> +#define MPU3050_PWR_MGM_STBY_YG BIT(4)
> +#define MPU3050_PWR_MGM_STBY_XG BIT(5)
> +#define MPU3050_PWR_MGM_SLEEP BIT(6)
> +#define MPU3050_PWR_MGM_RESET BIT(7)
> +#define MPU3050_PWR_MGM_MASK 0xff
> +
> +/*
> + * Fullscale precision is (for finest precision) +/- 250 deg/s, so the full
> + * scale is actually 500 deg/s. All 16 bits are then used to cover this scale,
> + * so 2^15 positive numbers and 2^15 negative numbers.
I don't get comment regarding 16 bits; does it mean -32768 is not used?
> + */
> +static unsigned int mpu3050_fs_precision[] = {
> + IIO_DEGREE_TO_RAD(250),
> + IIO_DEGREE_TO_RAD(500),
> + IIO_DEGREE_TO_RAD(1000),
> + IIO_DEGREE_TO_RAD(2000)
> +};
> +
> +/*
> + * Regulator names
> + */
> +static const char mpu3050_reg_vdd[] = "vdd";
> +static const char mpu3050_reg_vlogic[] = "vlogic";
> +
> +static unsigned int mpu3050_get_freq(struct mpu3050 *mpu3050)
> +{
> + unsigned int freq;
> +
> + if (mpu3050->lpf == MPU3050_DLPF_CFG_256HZ_NOLPF2)
> + freq = 8000;
> + else
> + freq = 1000;
> + freq /= (mpu3050->divisor + 1);
> +
> + return freq;
> +}
> +
> +static int mpu3050_start_sampling(struct mpu3050 *mpu3050)
> +{
> + __be16 raw_val[3];
> + int ret;
> + int i;
> +
> + /* Reset */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_PWR_MGM,
> + MPU3050_PWR_MGM_RESET,
> + MPU3050_PWR_MGM_RESET);
> + if (ret)
> + return ret;
> +
> + /* Turn on the Z-axis PLL */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_PWR_MGM,
> + MPU3050_PWR_MGM_CLKSEL_MASK,
> + MPU3050_PWR_MGM_PLL_Z);
> + if (ret)
> + return ret;
> +
> + /* Write calibration offset registers */
> + for (i = 0; i < 3; i++)
> + raw_val[i] = cpu_to_be16(mpu3050->calibration[i]);
> +
> + ret = regmap_bulk_write(mpu3050->map,
> + MPU3050_X_OFFS_USRH,
> + raw_val,
> + sizeof(raw_val));
> + if (ret)
> + return ret;
> +
> + /* Set low pass filter (sample rate), sync and full scale */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_DLPF_FS_SYNC,
> + MPU3050_EXT_SYNC_NONE << MPU3050_EXT_SYNC_SHIFT |
> + mpu3050->fullscale << MPU3050_FS_SHIFT |
> + mpu3050->lpf << MPU3050_DLPF_CFG_SHIFT);
> + if (ret)
> + return ret;
> +
> + /* Set up sampling frequency */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_SMPLRT_DIV,
> + mpu3050->divisor);
> + if (ret)
> + return ret;
> +
> + /*
> + * Max 50 ms start-up time after setting DLPF_FS_SYNC
> + * according to the data sheet, then wait for the next sample
> + * at this frequency T = 1000/f ms.
> + */
> + msleep(50 + 1000/mpu3050_get_freq(mpu3050));
maybe space around /
> +
> + return 0;
> +}
> +
> +static int mpu3050_set_8khz_samplerate(struct mpu3050 *mpu3050)
> +{
> + int ret;
> + u8 divisor;
> + enum mpu3050_lpf lpf;
> +
> + lpf = mpu3050->lpf;
> + divisor = mpu3050->divisor;
> +
> + mpu3050->lpf = LPF_256_HZ_NOLPF; /* 8 kHz base frequency */
> + mpu3050->divisor = 0; /* Divide by 1 */
> + ret = mpu3050_start_sampling(mpu3050);
> +
> + mpu3050->lpf = lpf;
> + mpu3050->divisor = divisor;
> +
> + return ret;
> +}
> +
> +static int mpu3050_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2,
> + long mask)
> +{
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> + int ret = -EINVAL;
I'd rather not init ret and directly
return -EINVAL instead of break
> + __be16 raw_val;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_OFFSET:
> + switch (chan->type) {
> + case IIO_TEMP:
> + /* The temperature scaling is (x+23000)/280 Celsius */
> + *val = 23000;
> + return IIO_VAL_INT;
> + default:
> + break;
> + }
> + case IIO_CHAN_INFO_CALIBBIAS:
> + switch (chan->type) {
> + case IIO_ANGL_VEL:
> + *val = mpu3050->calibration[chan->scan_index-1];
> + return IIO_VAL_INT;
> + default:
> + break;
> + }
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + *val = mpu3050_get_freq(mpu3050);
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->type) {
> + case IIO_TEMP:
> + /* Millidegrees, see about temperature scaling above */
> + *val = 1000;
> + *val2 = 280;
> + return IIO_VAL_FRACTIONAL;
> + case IIO_ANGL_VEL:
> + /*
> + * Convert to the corresponding full scale in
> + * radians. All 16 bits are used with sign to
> + * span the available scale.
> + */
> + *val = mpu3050_fs_precision[mpu3050->fullscale];
> + *val2 = S16_MAX + 1; /* 2^15 + 1 (also the zero) */
really 2^15 + 1
> + return IIO_VAL_FRACTIONAL;
> + default:
> + break;
> + }
> + case IIO_CHAN_INFO_RAW:
> + /* Resume device */
> + pm_runtime_get_sync(mpu3050->dev);
> + mutex_lock(&mpu3050->lock);
> +
> + ret = mpu3050_set_8khz_samplerate(mpu3050);
> + if (ret)
> + goto out_read_raw_unlock;
> +
> + switch (chan->type) {
> + case IIO_TEMP:
> + ret = regmap_bulk_read(mpu3050->map,
> + MPU3050_TEMP_H,
> + &raw_val,
> + sizeof(raw_val));
> + if (ret) {
> + dev_err(mpu3050->dev,
> + "error reading temperature\n");
> + goto out_read_raw_unlock;
> + }
> +
> + *val = be16_to_cpu(raw_val);
> + ret = IIO_VAL_INT;
> +
> + goto out_read_raw_unlock;
> + case IIO_ANGL_VEL:
> + ret = regmap_bulk_read(mpu3050->map,
> + MPU3050_AXIS_REGS(chan->scan_index-1),
> + &raw_val,
> + sizeof(raw_val));
> + if (ret) {
> + dev_err(mpu3050->dev,
> + "error reading axis data\n");
> + goto out_read_raw_unlock;
> + }
> +
> + *val = be16_to_cpu(raw_val);
> + ret = IIO_VAL_INT;
> +
> + goto out_read_raw_unlock;
> + default:
> + break;
> + }
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +
> +out_read_raw_unlock:
> + mutex_unlock(&mpu3050->lock);
> + pm_runtime_mark_last_busy(mpu3050->dev);
> + pm_runtime_put_autosuspend(mpu3050->dev);
> +
> + return ret;
> +}
> +
> +static int mpu3050_write_raw(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + int val, int val2, long mask)
> +{
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> + /*
> + * Couldn't figure out a way to precalculate these at compile time.
> + */
> + unsigned int fs250 =
> + DIV_ROUND_CLOSEST(mpu3050_fs_precision[0] * 1000000,
> + S16_MAX + 1);
> + unsigned int fs500 =
> + DIV_ROUND_CLOSEST(mpu3050_fs_precision[1] * 1000000,
> + S16_MAX + 1);
> + unsigned int fs1000 =
> + DIV_ROUND_CLOSEST(mpu3050_fs_precision[2] * 1000000,
> + S16_MAX + 1);
> + unsigned int fs2000 =
> + DIV_ROUND_CLOSEST(mpu3050_fs_precision[3] * 1000000,
> + S16_MAX + 1);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_CALIBBIAS:
> + if (chan->type != IIO_ANGL_VEL)
> + return -EINVAL;
> + mpu3050->calibration[chan->scan_index-1] = val;
> + return 0;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + /*
> + * The max samplerate is 8000 Hz, the minimum
> + * 1000 / 256 ~= 4 Hz
> + */
> + if (val < 4 || val > 8000)
> + return -EINVAL;
> +
> + /*
> + * Above 1000 Hz we must turn off the digital low pass filter
> + * so we get a base frequency of 8kHz to the divider
> + */
> + if (val > 1000) {
> + mpu3050->lpf = LPF_256_HZ_NOLPF;
> + mpu3050->divisor = DIV_ROUND_CLOSEST(8000, val) - 1;
> + return 0;
> + }
> +
> + mpu3050->lpf = LPF_188_HZ;
> + mpu3050->divisor = DIV_ROUND_CLOSEST(1000, val) - 1;
> + return 0;
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type != IIO_ANGL_VEL)
> + return -EINVAL;
> + /*
> + * We support +/-250, +/-500, +/-1000 and +/2000 deg/s
> + * which means we need to round to the closest radians
> + * which will be roughly +/-4.3, +/-8.7, +/-17.5, +/-35
> + * rad/s. The scale is then for the 16 bits used to cover
> + * it 1/(2^15+1) of that.
2^15 + 1?
> + */
> +
> + /* Just too large, set the max range */
> + if (val != 0) {
> + mpu3050->fullscale = FS_2000_DPS;
> + return 0;
> + }
> +
> + /*
> + * Now we're dealing with fractions below zero in millirad/s
> + * do some integer interpolation and match with the closest
> + * fullscale in the table.
> + */
> + if (val2 <= fs250 ||
> + val2 < ((fs500 + fs250) / 2))
> + mpu3050->fullscale = FS_250_DPS;
> + else if (val2 <= fs500 ||
> + val2 < ((fs1000 + fs500) / 2))
> + mpu3050->fullscale = FS_500_DPS;
> + else if (val2 <= fs1000 ||
> + val2 < ((fs2000 + fs1000) / 2))
> + mpu3050->fullscale = FS_1000_DPS;
> + else
> + /* Catch-all */
> + mpu3050->fullscale = FS_2000_DPS;
> + return 0;
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static irqreturn_t mpu3050_trigger_handler(int irq, void *p)
> +{
> + const struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> + int ret;
> + /*
> + * Temperature 1*16 bits
> + * Three axes 3*16 bits
> + * Timestamp 64 bits (4*16 bits)
> + * Sum total 8*16 bits
> + */
> + __be16 hw_values[8];
> + s64 timestamp;
> + unsigned int datums_from_fifo = 0;
> +
> + /*
> + * If we're using the hardware trigger, get the precise timestamp from
> + * the top half of the threaded IRQ handler. Otherwise get the
> + * timestamp here so it will be close in time to the actual values
> + * read from the registers.
> + */
> + if (mpu3050->hw_irq_trigger)
> + timestamp = mpu3050->hw_timestamp;
> + else
> + timestamp = iio_get_time_ns(indio_dev);
> +
> + mutex_lock(&mpu3050->lock);
> +
> + /* Using the hardware IRQ trigger? Check the buffer then. */
> + if (mpu3050->hw_irq_trigger) {
> + __be16 raw_fifocnt;
> + u16 fifocnt;
> + /* X, Y, Z + temperature */
> + unsigned int bytes_per_datum = 8;
> + bool fifo_overflow = false;
> +
> + ret = regmap_bulk_read(mpu3050->map,
> + MPU3050_FIFO_COUNT_H,
> + &raw_fifocnt,
> + sizeof(raw_fifocnt));
> + if (ret)
> + goto out_trigger_unlock;
> + fifocnt = be16_to_cpu(raw_fifocnt);
> +
> + if (fifocnt == 512) {
> + dev_info(mpu3050->dev,
> + "FIFO overflow! Emptying and resetting FIFO\n");
> + fifo_overflow = true;
> + /* Reset and enable the FIFO */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_USR_CTRL,
> + MPU3050_USR_CTRL_FIFO_EN |
> + MPU3050_USR_CTRL_FIFO_RST,
> + MPU3050_USR_CTRL_FIFO_EN |
> + MPU3050_USR_CTRL_FIFO_RST);
> + if (ret) {
> + dev_info(mpu3050->dev, "error resetting FIFO\n");
> + goto out_trigger_unlock;
> + }
> + mpu3050->pending_fifo_footer = false;
> + }
> +
> + if (fifocnt)
> + dev_dbg(mpu3050->dev,
> + "%d bytes in the FIFO\n",
> + fifocnt);
> +
> + while (!fifo_overflow && fifocnt > bytes_per_datum) {
> + unsigned int toread;
> + unsigned int offset;
> + __be16 fifo_values[5];
> +
> + /*
> + * If there is a FIFO footer in the pipe, first clear
> + * that out. This follows the complex algorithm in the
> + * datasheet that states that you may never leave the
> + * FIFO empty after the first reading: you have to
> + * always leave two footer bytes in it. The footer is
> + * in practice just two zero bytes.
> + */
> + if (mpu3050->pending_fifo_footer) {
> + toread = bytes_per_datum + 2;
> + offset = 0;
> + } else {
> + toread = bytes_per_datum;
> + offset = 1;
> + fifo_values[0] = 0xAAAA;
> + }
> +
> + ret = regmap_bulk_read(mpu3050->map,
> + MPU3050_FIFO_R,
> + &fifo_values[offset],
> + toread);
> +
> + dev_dbg(mpu3050->dev,
> + "%04x %04x %04x %04x %04x\n",
> + fifo_values[0],
should probably use be16_to_cpu() on the values read for debug output
> + fifo_values[1],
> + fifo_values[2],
> + fifo_values[3],
> + fifo_values[4]);
> +
> + iio_push_to_buffers_with_timestamp(indio_dev,
> + &fifo_values[1],
> + timestamp);
> +
> + fifocnt -= toread;
> + datums_from_fifo++;
> + mpu3050->pending_fifo_footer = true;
> +
> + /*
> + * If we're emptying the FIFO, just make sure to
> + * check if something new appeared.
> + */
> + if (fifocnt < bytes_per_datum) {
> + ret = regmap_bulk_read(mpu3050->map,
> + MPU3050_FIFO_COUNT_H,
> + &raw_fifocnt,
> + sizeof(raw_fifocnt));
> + if (ret)
> + goto out_trigger_unlock;
> + fifocnt = be16_to_cpu(raw_fifocnt);
> + }
> +
> + if (fifocnt < bytes_per_datum)
> + dev_dbg(mpu3050->dev,
> + "%d bytes left in the FIFO\n",
> + fifocnt);
> +
> + /*
> + * At this point, the timestamp that triggered the
> + * hardware interrupt is no longer valid for what
> + * we are reading (the interrupt likely fired for
> + * the value on the top of the FIFO), so re-stamp
> + * the time.
> + */
> + timestamp = iio_get_time_ns(indio_dev);
> + }
> + }
> +
> + /*
> + * If we picked some datums from the FIFO that's enough, else
> + * fall through and just read from the current value registers.
> + * This happens in two cases:
> + *
> + * - We are using some other trigger (external, like an HRTimer)
> + * than the sensor's own sample generator. In this case the
> + * sensor is just set to the max sampling frequency and we give
> + * the trigger a copy of the latest value every time we get here.
> + *
> + * - The hardware trigger is active but unused and we actually use
> + * another trigger which calls here with a frequency higher
> + * than what the device provides data. We will then just read
> + * duplicate values directly from the hardware registers.
> + */
> + if (datums_from_fifo) {
> + dev_dbg(mpu3050->dev,
> + "read %d datums from the FIFO\n",
> + datums_from_fifo);
> + goto out_trigger_unlock;
> + }
> +
> + ret = regmap_bulk_read(mpu3050->map,
> + MPU3050_TEMP_H,
> + &hw_values,
> + sizeof(hw_values));
> + if (ret) {
> + dev_err(mpu3050->dev,
> + "error reading axis data\n");
> + goto out_trigger_unlock;
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev,
> + hw_values,
> + timestamp);
> +
> +out_trigger_unlock:
> + mutex_unlock(&mpu3050->lock);
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int mpu3050_buffer_preenable(struct iio_dev *indio_dev)
> +{
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +
> + pm_runtime_get_sync(mpu3050->dev);
> +
> + /* Unless we have OUR trigger active, run at full speed */
> + if (!mpu3050->hw_irq_trigger)
> + return mpu3050_set_8khz_samplerate(mpu3050);
> +
> + return 0;
> +}
> +
> +static int mpu3050_buffer_postdisable(struct iio_dev *indio_dev)
> +{
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +
> + pm_runtime_mark_last_busy(mpu3050->dev);
> + pm_runtime_put_autosuspend(mpu3050->dev);
> +
> + return 0;
> +}
> +
> +static const struct iio_buffer_setup_ops mpu3050_buffer_setup_ops = {
> + .preenable = mpu3050_buffer_preenable,
> + .postenable = iio_triggered_buffer_postenable,
> + .predisable = iio_triggered_buffer_predisable,
> + .postdisable = mpu3050_buffer_postdisable,
> +};
> +
> +static const struct iio_mount_matrix *
> +mpu3050_get_mount_matrix(const struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan)
> +{
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +
> + return &mpu3050->orientation;
> +}
> +
> +static const struct iio_chan_spec_ext_info mpu3050_ext_info[] = {
> + IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, mpu3050_get_mount_matrix),
> + { },
> +};
> +
> +#define MPU3050_AXIS_CHANNEL(axis, index) \
> + { \
> + .type = IIO_ANGL_VEL, \
> + .modified = 1, \
> + .channel2 = IIO_MOD_##axis, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_CALIBBIAS), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
> + .ext_info = mpu3050_ext_info, \
> + .scan_index = index, \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 16, \
> + .storagebits = 16, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +static const struct iio_chan_spec mpu3050_channels[] = {
> + {
> + .type = IIO_TEMP,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) |
> + BIT(IIO_CHAN_INFO_OFFSET),
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 's',
> + .realbits = 16,
> + .storagebits = 16,
> + .endianness = IIO_BE,
> + },
> + },
> + MPU3050_AXIS_CHANNEL(X, 1),
> + MPU3050_AXIS_CHANNEL(Y, 2),
> + MPU3050_AXIS_CHANNEL(Z, 3),
> + IIO_CHAN_SOFT_TIMESTAMP(4),
> +};
> +
> +/* Four channels apart from timestamp, scan mask = 0x0f */
> +static const unsigned long mpu3050_scan_masks[] = { 0xf, 0 };
> +
> +/*
> + * These are just the hardcoded factors resulting from the more elaborate
> + * calculations done with fractions in the scale raw get/set functions.
> + */
> +static IIO_CONST_ATTR(anglevel_scale_available,
> + "0.000122070 "
> + "0.000274658 "
> + "0.000518798 "
> + "0.001068115");
> +
> +static struct attribute *mpu3050_attributes[] = {
> + &iio_const_attr_anglevel_scale_available.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group mpu3050_attribute_group = {
> + .attrs = mpu3050_attributes,
> +};
> +
> +static const struct iio_info mpu3050_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = mpu3050_read_raw,
> + .write_raw = mpu3050_write_raw,
> + .attrs = &mpu3050_attribute_group,
> + .driver_module = THIS_MODULE,
> +};
> +
> +/**
> + * mpu3050_read_mem() - read MPU-3050 internal memory
> + * @mpu3050: device to read from
> + * @bank: target bank
> + * @addr: target address
> + * @len: number of bytes
> + * @buf: the buffer to store the read bytes in
> + */
> +static int mpu3050_read_mem(struct mpu3050 *mpu3050,
> + u8 bank,
> + u8 addr,
> + u8 len,
> + u8 *buf)
> +{
> + int ret;
> +
> + ret = regmap_write(mpu3050->map,
> + MPU3050_BANK_SEL,
> + bank);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(mpu3050->map,
> + MPU3050_MEM_START_ADDR,
> + addr);
> + if (ret)
> + return ret;
> +
> + return regmap_bulk_read(mpu3050->map,
> + MPU3050_MEM_R_W,
> + buf,
> + len);
> +}
> +
> +static int mpu3050_hw_init(struct mpu3050 *mpu3050)
> +{
> + int ret;
> + u8 otp[8];
> +
> + /* Reset */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_PWR_MGM,
> + MPU3050_PWR_MGM_RESET,
> + MPU3050_PWR_MGM_RESET);
> + if (ret)
> + return ret;
> +
> + /* Turn on the PLL */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_PWR_MGM,
> + MPU3050_PWR_MGM_CLKSEL_MASK,
> + MPU3050_PWR_MGM_PLL_Z);
> + if (ret)
> + return ret;
> +
> + /* Disable IRQs */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_INT_CFG,
> + 0);
> + if (ret)
> + return ret;
> +
> + /* Read out the 8 bytes of OTP (one-time-programmable) memory */
> + ret = mpu3050_read_mem(mpu3050,
> + (MPU3050_MEM_PRFTCH |
> + MPU3050_MEM_USER_BANK |
> + MPU3050_MEM_OTP_BANK_0),
> + 0,
> + sizeof(otp),
> + otp);
> + if (ret)
> + return ret;
> +
> + /* This is device-unique data so it goes into the entropy pool */
> + add_device_randomness(otp, sizeof(otp));
> +
> + dev_info(mpu3050->dev,
> + "die ID: %04X, wafer ID: %02X, A lot ID: %04X, "
> + "W lot ID: %03X, WP ID: %01X, rev ID: %02X\n",
> + /* Die ID, bits 0-12 */
> + (otp[1] << 8 | otp[0]) & 0x1fff,
> + /* Wafer ID, bits 13-17 */
> + ((otp[2] << 8 | otp[1]) & 0x03e0) >> 5,
> + /* A lot ID, bits 18-33 */
> + ((otp[4] << 16 | otp[3] << 8 | otp[2]) & 0x3fffc) >> 2,
> + /* W lot ID, bits 34-45 */
> + ((otp[5] << 8 | otp[4]) & 0x3ffc) >> 2,
> + /* WP ID, bits 47-49 */
> + ((otp[6] << 8 | otp[5]) & 0x0380) >> 7,
> + /* rev ID, bits 50-55 */
> + otp[6] >> 2);
> +
> + return 0;
> +}
> +
> +int mpu3050_power_up(struct mpu3050 *mpu3050)
> +{
> + int ret;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(mpu3050->regs), mpu3050->regs);
> + if (ret) {
> + dev_err(mpu3050->dev, "Cannot enable regulators\n");
most messages start lowercase in this driver
> + return ret;
> + }
> + /*
> + * 20-100 ms start-up time for register read/write according to
> + * the datasheet, be on the safe side and wait 200 ms.
> + */
> + msleep(200);
> +
> + /* Take device out of sleep mode */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_PWR_MGM,
> + MPU3050_PWR_MGM_SLEEP,
> + 0);
> + if (ret) {
> + dev_err(mpu3050->dev, "error setting power mode\n");
> + return ret;
> + }
> + msleep(10);
> +
> + return 0;
> +}
> +
> +int mpu3050_power_down(struct mpu3050 *mpu3050)
> +{
> + int ret;
> +
> + /*
> + * Put MPU-3050 into sleep mode before cutting regulators.
> + * This is important, because we may not be the sole user
> + * of the regulator so the power may stay on after this, and
> + * then we would be wasting power unless we go to sleep mode
> + * first.
> + */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_PWR_MGM,
> + MPU3050_PWR_MGM_SLEEP,
> + MPU3050_PWR_MGM_SLEEP);
> + if (ret)
> + dev_err(mpu3050->dev, "error putting MPU-3050 to sleep\n");
necessary to mention the part name (MPU-3050) in the message?
> +
> + ret = regulator_bulk_disable(ARRAY_SIZE(mpu3050->regs), mpu3050->regs);
> + if (ret)
> + dev_err(mpu3050->dev, "error disable MPU-3050 regulators\n");
disabling
> +
> + return 0;
> +}
> +
> +static irqreturn_t mpu3050_irq_handler(int irq, void *p)
> +{
> + struct iio_trigger *trig = p;
> + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +
> + if (!mpu3050->hw_irq_trigger)
> + return IRQ_NONE;
> +
> + /* Get the time stamp as close in time as possible */
> + mpu3050->hw_timestamp = iio_get_time_ns(indio_dev);
> + return IRQ_WAKE_THREAD;
> +}
> +
> +static irqreturn_t mpu3050_irq_thread(int irq, void *p)
> +{
> + struct iio_trigger *trig = p;
> + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> + unsigned int val;
> + int ret;
> +
> + /* ACK IRQ and check if it was from us */
> + ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
> + if (ret) {
> + dev_err(mpu3050->dev, "error reading IRQ status\n");
> + return IRQ_HANDLED;
> + }
> + if (!(val & MPU3050_INT_STATUS_RAW_RDY))
> + return IRQ_NONE;
> +
> + iio_trigger_poll_chained(p);
> + return IRQ_HANDLED;
> +}
> +
> +/**
> + * mpu3050_drdy_trigger_set_state() - set data ready interrupt state
> + * @trig: trigger instance
> + * @enable: true if trigger should be enabled, false to disable
> + */
> +static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
> + bool enable)
> +{
> + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> + unsigned int val;
> + int ret;
> +
> + /* Disabling trigger: disable interrupt and return */
> + if (!enable) {
> + /* Disable all interrupts */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_INT_CFG,
> + 0);
> + if (ret)
> + dev_err(mpu3050->dev, "error disabling IRQ\n");
> +
> + /* Clear IRQ flag */
> + ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
> + if (ret)
> + dev_err(mpu3050->dev, "error clearing IRQ status\n");
> +
> + /* Disable all things in the FIFO and reset it */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_FIFO_EN,
> + 0);
> + if (ret)
> + dev_err(mpu3050->dev, "error disabling FIFO\n");
> +
> + ret = regmap_write(mpu3050->map,
> + MPU3050_USR_CTRL,
> + MPU3050_USR_CTRL_FIFO_RST);
> + if (ret)
> + dev_err(mpu3050->dev, "error resetting FIFO\n");
> +
> + pm_runtime_mark_last_busy(mpu3050->dev);
> + pm_runtime_put_autosuspend(mpu3050->dev);
> + mpu3050->hw_irq_trigger = false;
> + return 0;
> + }
> +
> + /* Else we're enabling the trigger from this point */
> + pm_runtime_get_sync(mpu3050->dev);
> + mpu3050->hw_irq_trigger = true;
> +
> + /* Disable all things in the FIFO */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_FIFO_EN,
> + 0);
> + if (ret)
> + return ret;
> +
> + /* Reset and enable the FIFO */
> + ret = regmap_update_bits(mpu3050->map,
> + MPU3050_USR_CTRL,
> + MPU3050_USR_CTRL_FIFO_EN |
> + MPU3050_USR_CTRL_FIFO_RST,
> + MPU3050_USR_CTRL_FIFO_EN |
> + MPU3050_USR_CTRL_FIFO_RST);
> + if (ret)
> + return ret;
> +
> + mpu3050->pending_fifo_footer = false;
> +
> + /* Turn on the FIFO for temp+X+Y+Z */
> + ret = regmap_write(mpu3050->map,
> + MPU3050_FIFO_EN,
> + MPU3050_FIFO_EN_TEMP_OUT |
> + MPU3050_FIFO_EN_GYRO_XOUT |
> + MPU3050_FIFO_EN_GYRO_YOUT |
> + MPU3050_FIFO_EN_GYRO_ZOUT |
> + MPU3050_FIFO_EN_FOOTER);
> + if (ret)
> + return ret;
> +
> + /* Configure the sample engine */
> + ret = mpu3050_start_sampling(mpu3050);
> + if (ret)
> + return ret;
> +
> + /* Clear IRQ flag */
> + ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
> + if (ret)
> + dev_err(mpu3050->dev, "error clearing IRQ status\n");
> +
> + /* Give us interrupts whenever there is new data ready */
> + val = MPU3050_INT_RAW_RDY_EN;
> +
> + if (mpu3050->irq_actl)
> + val |= MPU3050_INT_ACTL;
> + if (mpu3050->irq_latch)
> + val |= MPU3050_INT_LATCH_EN;
> + if (mpu3050->irq_opendrain)
> + val |= MPU3050_INT_OPEN;
> +
> + ret = regmap_write(mpu3050->map,
> + MPU3050_INT_CFG,
> + val);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static const struct iio_trigger_ops mpu3050_trigger_ops = {
> + .owner = THIS_MODULE,
> + .set_trigger_state = mpu3050_drdy_trigger_set_state,
> +};
> +
> +static int mpu3050_trigger_probe(struct iio_dev *indio_dev, int irq)
> +{
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> + unsigned long irq_trig;
> + int ret;
> +
> + mpu3050->trig = devm_iio_trigger_alloc(&indio_dev->dev,
> + "%s-dev%d",
> + indio_dev->name,
> + indio_dev->id);
> + if (!mpu3050->trig)
> + return -ENOMEM;
> +
> + /* Check if IRQ is open drain */
> + if (of_property_read_bool(mpu3050->dev->of_node, "drive-open-drain"))
> + mpu3050->irq_opendrain = true;
> +
> + irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
> + /*
> + * Configure the interrupt generator hardware to supply whatever
> + * the interrupt is configured for, edges low/high level low/high,
> + * we can provide it all.
> + */
> + switch (irq_trig) {
> + case IRQF_TRIGGER_RISING:
> + dev_info(&indio_dev->dev,
> + "pulse interrupts on the rising edge\n");
> + if (mpu3050->irq_opendrain) {
> + dev_info(&indio_dev->dev,
> + "rising edge incompatible with open drain\n");
> + mpu3050->irq_opendrain = false;
> + }
> + break;
> + case IRQF_TRIGGER_FALLING:
> + mpu3050->irq_actl = true;
> + dev_info(&indio_dev->dev,
> + "pulse interrupts on the falling edge\n");
> + break;
> + case IRQF_TRIGGER_HIGH:
> + mpu3050->irq_latch = true;
> + dev_info(&indio_dev->dev,
> + "interrupts active high level\n");
> + if (mpu3050->irq_opendrain) {
> + dev_info(&indio_dev->dev,
> + "active high incompatible with open drain\n");
> + mpu3050->irq_opendrain = false;
> + }
> + /*
> + * With level IRQs, we mask the IRQ until it is processed,
> + * but with edge IRQs (pulses) we can queue several interrupts
> + * in the top half.
> + */
> + irq_trig |= IRQF_ONESHOT;
> + break;
> + case IRQF_TRIGGER_LOW:
> + mpu3050->irq_latch = true;
> + mpu3050->irq_actl = true;
> + irq_trig |= IRQF_ONESHOT;
> + dev_info(&indio_dev->dev,
> + "interrupts active low level\n");
> + break;
> + default:
> + /* This is the most preferred mode, if possible */
> + dev_err(&indio_dev->dev,
> + "unsupported IRQ trigger specified (%lx), enforce "
> + "rising edge\n", irq_trig);
> + irq_trig = IRQF_TRIGGER_RISING;
> + break;
> + }
> +
> + /* An open drain line can be shared with several devices */
> + if (mpu3050->irq_opendrain)
> + irq_trig |= IRQF_SHARED;
> +
> + ret = request_threaded_irq(irq,
> + mpu3050_irq_handler,
> + mpu3050_irq_thread,
> + irq_trig,
> + mpu3050->trig->name,
> + mpu3050->trig);
> + if (ret) {
> + dev_err(mpu3050->dev,
> + "can't get IRQ %d, error %d\n", irq, ret);
> + return ret;
> + }
> +
> + mpu3050->irq = irq;
> + mpu3050->trig->dev.parent = mpu3050->dev;
> + mpu3050->trig->ops = &mpu3050_trigger_ops;
> + iio_trigger_set_drvdata(mpu3050->trig, indio_dev);
> +
> + ret = iio_trigger_register(mpu3050->trig);
> + if (ret)
> + return ret;
> +
> + indio_dev->trig = iio_trigger_get(mpu3050->trig);
> +
> + return 0;
> +}
> +
> +int mpu3050_common_probe(struct device *dev,
> + struct regmap *map,
> + int irq,
> + const char *name)
> +{
> + struct iio_dev *indio_dev;
> + struct mpu3050 *mpu3050;
> + unsigned int val;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*mpu3050));
> + if (!indio_dev)
> + return -ENOMEM;
> + mpu3050 = iio_priv(indio_dev);
> +
> + mpu3050->dev = dev;
> + mpu3050->map = map;
> + mutex_init(&mpu3050->lock);
> + /* Default fullscale: 2000 degrees per second */
> + mpu3050->fullscale = FS_2000_DPS;
> + /* 1 kHz, divide by 100, default frequency = 10 Hz */
> + mpu3050->lpf = MPU3050_DLPF_CFG_188HZ;
> + mpu3050->divisor = 99;
> +
> + /* Read the mounting matrix, if present */
> + ret = of_iio_read_mount_matrix(dev,
> + "mount-matrix",
> + &mpu3050->orientation);
> + if (ret)
> + return ret;
> +
> + /* Fetch and turn on regulators */
> + mpu3050->regs[0].supply = mpu3050_reg_vdd;
> + mpu3050->regs[1].supply = mpu3050_reg_vlogic;
> + ret = devm_regulator_bulk_get(dev,
> + ARRAY_SIZE(mpu3050->regs),
> + mpu3050->regs);
> + if (ret) {
> + dev_err(dev, "Cannot get regulators\n");
> + return ret;
> + }
> +
> + ret = mpu3050_power_up(mpu3050);
> + if (ret)
> + return ret;
> +
> + ret = regmap_read(map, MPU3050_CHIP_ID_REG, &val);
> + if (ret) {
> + dev_err(dev, "could not read device ID\n");
> + ret = -ENXIO;
ENODEV seems to be more popular in IIO
> +
> + goto err_power_down;
> + }
> +
> + if (val != MPU3050_CHIP_ID) {
> + dev_err(dev, "unsupported chip id %02x\n", (u8)val);
> + ret = -ENXIO;
> + goto err_power_down;
> + }
> +
> + ret = regmap_read(map, MPU3050_PRODUCT_ID_REG, &val);
> + if (ret) {
> + dev_err(dev, "could not read device ID\n");
> + ret = -ENXIO;
> +
> + goto err_power_down;
> + }
> + dev_info(dev, "found MPU-3050 part no: %d, version: %d\n",
> + ((val >> 4) & 0xf), (val & 0xf));
> +
> + ret = mpu3050_hw_init(mpu3050);
> + if (ret)
> + goto err_power_down;
> +
> + indio_dev->dev.parent = dev;
> + indio_dev->channels = mpu3050_channels;
> + indio_dev->num_channels = ARRAY_SIZE(mpu3050_channels);
> + indio_dev->info = &mpu3050_info;
> + indio_dev->available_scan_masks = mpu3050_scan_masks;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->name = name;
> +
> + ret = iio_triggered_buffer_setup(indio_dev,
> + iio_pollfunc_store_time,
> + mpu3050_trigger_handler,
> + &mpu3050_buffer_setup_ops);
> + if (ret) {
> + dev_err(dev, "triggered buffer setup failed\n");
> + goto err_power_down;
> + }
> +
> + ret = iio_device_register(indio_dev);
> + if (ret) {
> + dev_err(dev, "device register failed\n");
> + goto err_cleanup_buffer;
> + }
> +
> + dev_set_drvdata(dev, indio_dev);
> +
> + /* Check if we have an assigned IRQ to use as trigger */
> + if (irq) {
> + ret = mpu3050_trigger_probe(indio_dev, irq);
> + if (ret)
> + dev_err(dev, "failed to register trigger\n");
> + }
> +
> + /* Enable runtime PM */
> + pm_runtime_get_noresume(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> + /*
> + * Set autosuspend to two orders of magnitude larger than the
> + * start-up time. 100ms start-up time means 10000ms autosuspend,
> + * i.e. 10 seconds.
> + */
> + pm_runtime_set_autosuspend_delay(dev, 10000);
> + pm_runtime_use_autosuspend(dev);
> + pm_runtime_put(dev);
> +
> + return 0;
> +
> +err_cleanup_buffer:
> + iio_triggered_buffer_cleanup(indio_dev);
> +err_power_down:
> + mpu3050_power_down(mpu3050);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(mpu3050_common_probe);
> +
> +int mpu3050_common_remove(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
> + pm_runtime_get_sync(dev);
> + pm_runtime_put_noidle(dev);
> + pm_runtime_disable(dev);
> + mpu3050_power_down(mpu3050);
> + if (mpu3050->irq)
> + free_irq(mpu3050->irq, mpu3050);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(mpu3050_common_remove);
> +
> +#ifdef CONFIG_PM
> +static int mpu3050_runtime_suspend(struct device *dev)
> +{
> + return mpu3050_power_down(iio_priv(dev_get_drvdata(dev)));
> +}
> +
> +static int mpu3050_runtime_resume(struct device *dev)
> +{
> + return mpu3050_power_up(iio_priv(dev_get_drvdata(dev)));
> +}
> +#endif /* CONFIG_PM */
> +
> +const struct dev_pm_ops mpu3050_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> + pm_runtime_force_resume)
> + SET_RUNTIME_PM_OPS(mpu3050_runtime_suspend,
> + mpu3050_runtime_resume, NULL)
> +};
> +EXPORT_SYMBOL(mpu3050_dev_pm_ops);
> +
> +MODULE_AUTHOR("Linus Walleij");
> +MODULE_DESCRIPTION("MPU3050 gyroscope driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/iio/gyro/mpu3050-i2c.c b/drivers/iio/gyro/mpu3050-i2c.c
> new file mode 100644
> index 000000000000..06007200bf49
> --- /dev/null
> +++ b/drivers/iio/gyro/mpu3050-i2c.c
> @@ -0,0 +1,124 @@
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c-mux.h>
> +#include <linux/iio/iio.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "mpu3050.h"
> +
> +static const struct regmap_config mpu3050_i2c_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +};
> +
> +static int mpu3050_i2c_bypass_select(struct i2c_mux_core *mux, u32 chan_id)
> +{
> + struct mpu3050 *mpu3050 = i2c_mux_priv(mux);
> +
> + /* Just power up the device, that is all that is needed */
> + pm_runtime_get_sync(mpu3050->dev);
> + return 0;
> +}
> +
> +static int mpu3050_i2c_bypass_deselect(struct i2c_mux_core *mux, u32 chan_id)
> +{
> + struct mpu3050 *mpu3050 = i2c_mux_priv(mux);
> +
> + pm_runtime_mark_last_busy(mpu3050->dev);
> + pm_runtime_put_autosuspend(mpu3050->dev);
> + return 0;
> +}
> +
> +static int mpu3050_i2c_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct regmap *regmap;
> + const char *name;
> + struct mpu3050 *mpu3050;
> + int ret;
> +
> + if (!i2c_check_functionality(client->adapter,
> + I2C_FUNC_SMBUS_I2C_BLOCK))
> + return -EOPNOTSUPP;
> +
> + if (id)
> + name = id->name;
> + else
> + return -ENODEV;
> +
> + regmap = devm_regmap_init_i2c(client, &mpu3050_i2c_regmap_config);
> + if (IS_ERR(regmap)) {
> + dev_err(&client->dev, "Failed to register i2c regmap %d\n",
> + (int)PTR_ERR(regmap));
> + return PTR_ERR(regmap);
> + }
> +
> + ret = mpu3050_common_probe(&client->dev, regmap, client->irq, name);
> + if (ret)
> + return ret;
> +
> + /* The main driver is up, now register the I2C mux */
> + mpu3050 = iio_priv(dev_get_drvdata(&client->dev));
> + mpu3050->i2cmux = i2c_mux_alloc(client->adapter, &client->dev,
> + 1, 0, I2C_MUX_LOCKED | I2C_MUX_GATE,
> + mpu3050_i2c_bypass_select,
> + mpu3050_i2c_bypass_deselect);
> + /* Just fail the mux, there is no point in killing the driver */
> + if (!mpu3050->i2cmux)
> + dev_err(&client->dev, "failed to allocate I2C mux\n");
> + else {
> + mpu3050->i2cmux->priv = mpu3050;
> + ret = i2c_mux_add_adapter(mpu3050->i2cmux, 0, 0, 0);
> + if (ret)
> + dev_err(&client->dev, "failed to add I2C mux\n");
> + }
> +
> + return 0;
> +}
> +
> +static int mpu3050_i2c_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(&client->dev);
> + struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +
> + if (mpu3050->i2cmux)
> + i2c_mux_del_adapters(mpu3050->i2cmux);
> +
> + return mpu3050_common_remove(&client->dev);
> +}
> +
> +/*
> + * device id table is used to identify what device can be
> + * supported by this driver
> + */
> +static const struct i2c_device_id mpu3050_i2c_id[] = {
> + { "mpu3050" },
> + {}
> +};
> +MODULE_DEVICE_TABLE(i2c, mpu3050_i2c_id);
> +
> +static const struct of_device_id mpu3050_i2c_of_match[] = {
> + { .compatible = "invensense,mpu3050", .data = "mpu3050" },
> + /* Deprecated vendor ID from the Input driver */
> + { .compatible = "invn,mpu3050", .data = "mpu3050" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, mpu3050_i2c_of_match);
> +
> +static struct i2c_driver mpu3050_i2c_driver = {
> + .probe = mpu3050_i2c_probe,
> + .remove = mpu3050_i2c_remove,
> + .id_table = mpu3050_i2c_id,
> + .driver = {
> + .of_match_table = mpu3050_i2c_of_match,
> + .name = "mpu3050-i2c",
> + .pm = &mpu3050_dev_pm_ops,
> + },
> +};
> +module_i2c_driver(mpu3050_i2c_driver);
> +
> +MODULE_AUTHOR("Linus Walleij");
> +MODULE_DESCRIPTION("Invensense MPU3050 gyroscope driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/iio/gyro/mpu3050.h b/drivers/iio/gyro/mpu3050.h
> new file mode 100644
> index 000000000000..85f3a5b4ba04
> --- /dev/null
> +++ b/drivers/iio/gyro/mpu3050.h
> @@ -0,0 +1,96 @@
> +#include <linux/iio/iio.h>
> +#include <linux/mutex.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/i2c.h>
> +
> +/**
> + * enum mpu3050_fullscale - indicates the full range of the sensor in deg/sec
> + */
> +enum mpu3050_fullscale {
> + FS_250_DPS = 0,
> + FS_500_DPS,
> + FS_1000_DPS,
> + FS_2000_DPS,
> +};
> +
> +/**
> + * enum mpu3050_lpf - indicates the low pass filter width
> + */
> +enum mpu3050_lpf {
> + /* This implicity sets sample frequency to 8 kHz */
> + LPF_256_HZ_NOLPF = 0,
> + /* All others sets the sample frequenct to 1 kHz */
> + LPF_188_HZ,
> + LPF_98_HZ,
> + LPF_42_HZ,
> + LPF_20_HZ,
> + LPF_10_HZ,
> + LPF_5_HZ,
> + LPF_2100_HZ_NOLPF,
> +};
> +
> +enum mpu3050_axis {
> + AXIS_X = 0,
> + AXIS_Y,
> + AXIS_Z,
> + AXIS_MAX,
> +};
> +
> +/**
> + * struct mpu3050 - instance state container for the device
> + * @dev: parent device for this instance
> + * @orientation: mounting matrix, flipped axis etc
> + * @map: regmap to reach the registers
> + * @lock: serialization lock to marshal all requests
> + * @irq: the IRQ used for this device
> + * @regs: the regulators to power this device
> + * @fullscale: the current fullscale setting for the device
> + * @lpf: digital low pass filter setting for the device
> + * @divisor: base frequency divider: divides 8 or 1 kHz
> + * @calibration: the three signed 16-bit calibration settings that
> + * get written into the offset registers for each axis to compensate
> + * for DC offsets
> + * @trig: trigger for the MPU-3050 interrupt, if present
> + * @hw_irq_trigger: hardware interrupt trigger is in use
> + * @irq_actl: interrupt is active low
> + * @irq_latch: latched IRQ, this means that it is a level IRQ
> + * @irq_opendrain: the interrupt line shall be configured open drain
> + * @pending_fifo_footer: tells us if there is a pending footer in the FIFO
> + * that we have to read out first when handling the FIFO
> + * @hw_timestamp: latest hardware timestamp from the trigger IRQ, when in
> + * use
> + * @i2cmux: an I2C mux reflecting the fact that this sensor is a hub with
> + * a pass-through I2C interface coming out of it: this device needs to be
> + * powered up in order to reach devices on the other side of this mux
> + */
> +struct mpu3050 {
> + struct device *dev;
> + struct iio_mount_matrix orientation;
> + struct regmap *map;
> + struct mutex lock;
> + int irq;
> + struct regulator_bulk_data regs[2];
> + enum mpu3050_fullscale fullscale;
> + enum mpu3050_lpf lpf;
> + u8 divisor;
> + s16 calibration[3];
> + struct iio_trigger *trig;
> + bool hw_irq_trigger;
> + bool irq_actl;
> + bool irq_latch;
> + bool irq_opendrain;
> + bool pending_fifo_footer;
> + s64 hw_timestamp;
> + struct i2c_mux_core *i2cmux;
> +};
> +
> +/* Probe called from different transports */
> +int mpu3050_common_probe(struct device *dev,
> + struct regmap *map,
> + int irq,
> + const char *name);
> +int mpu3050_common_remove(struct device *dev);
> +
> +/* PM ops */
> +extern const struct dev_pm_ops mpu3050_dev_pm_ops;
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
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