[PATCH v5 0/6] iio: gyro: add fxas21002c driver

[PATCH v5 0/6] iio: gyro: add fxas21002c driver

[Rui Miguel Silva]

Hi,
This series introduce a NXP fxas21002c tri axis gyroscope driver [0]
It add a core implementaiton plus an i2c and spi.

This device can be found in the warp7 board [1], where it was tested.

---
Cheers,
   Rui

v4->v5:
Jonathan Cameron:
  - remove init ret
  - change handle of iio register, buffer and trigger in probe and
   remove (I think this is what you mean, Jonathan)

v3->v4:
Tomasz Duszynski:
  - mention irq flags in bindings
  - add reference to drive-open-drain in bindings
  - fix headers files
  - drop comas in of_device_id sentinel
  - drop of_match_ptr
  - use probe_new

Jonathan Cameron:
  - disable vdd regulator in case of vddio fail
  - use devm_add_action_or_reset
  - simpler functions returns
  - remove noisy dev_info
  - remove EAGAIN from runtime_suspend

v2->v3:
Jonathan Cameron:
  - cacheline aligned (DMA safe buffer)
     Great presentation [2] and links in the presentation, thanks
  - global renaming, including filenames, fxas2100x->fxas21002c
  - provide spi info in dts bidings
  - Remove SPI_MASTER in Kconfig i2c patch and move it to right patch
  - remove extra blank line in comment
  - add break range_value_from_fs after found
  - in range_value_from_fs use local variable
  - remove mode check at mode_set
  - combine two if statements in mode_set
  - in scale_get return 0 and let caller to set IIO_VAL_FRACTIONAL
  - remove dev_err from vdd_io regulator get
  - handle regulator error path
  - devm_add_action
  - check unwind order
  - simplify data in _suspend and alike
  - disable regulators at suspend
  - error handling at _resume
  - return -EAGAIN at runtime_resume

Rob Herring:
   - Set label as gyroscope

- add interrupt to bindings
- add entry to maintainers


v1->v2:
Peter Meerwal-Stadler:
  - changed (c) to current year
  - add regmap include file in .h
  - fix comments s/cuttof/cutoff/
  - add more info in mutex comment
  - check value in range_fs_from_value
  - ret not checked in range_value_from_fs
  - move mode to enum type
  - remove line between value get and validation of value in all file
  - pre-write, regmap_field_write, post_write refactoring
  - check val2 and val == 0 in write raw
  - check in_anglvel_scale: 7.8125?
  - trigger_handler: 2 => sizeof(s16)
  - check buffer size
  - print %02% to output chip id
  - remove !! as state is bool
  - trigger probe return devm_iio_trigger_register
  - remove error msg in case of devm_iio_device_register
Fabio Estebam:
  - rename FXAS2100X to FXAS21002
  - change compatible nxp,fxas2100x to the exact support
  - add VDD and VDDIO regulators in bindings and driver

[0]: https://www.nxp.com/docs/en/data-sheet/FXAS21002.pdf
[1]: https://www.element14.com/community/community/designcenter/single-board-computers/warp7/overview
[2]: https://events.linuxfoundation.org/wp-content/uploads/2017/12/20181023-Wolfram-Sang-ELCE18-safe_dma_buffers.pdf

Rui Miguel Silva (6):
  iio: gyro: add DT bindings to fxas21002c
  iio: gyro: add core driver for fxas21002c
  iio: gyro: fxas21002c: add i2c driver
  iio: gyro: fxas21002c: add spi driver
  ARM: dts: imx7s-warp: add fxas21002c gyroscope
  MAINTAINERS: add entry for fxas21002c gyro driver

 .../bindings/iio/gyroscope/nxp,fxas21002c.txt |   31 +
 MAINTAINERS                                   |   10 +
 arch/arm/boot/dts/imx7s-warp.dts              |    7 +
 drivers/iio/gyro/Kconfig                      |   22 +
 drivers/iio/gyro/Makefile                     |    3 +
 drivers/iio/gyro/fxas21002c.h                 |  151 +++
 drivers/iio/gyro/fxas21002c_core.c            | 1006 +++++++++++++++++
 drivers/iio/gyro/fxas21002c_i2c.c             |   69 ++
 drivers/iio/gyro/fxas21002c_spi.c             |   70 ++
 9 files changed, 1369 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
 create mode 100644 drivers/iio/gyro/fxas21002c.h
 create mode 100644 drivers/iio/gyro/fxas21002c_core.c
 create mode 100644 drivers/iio/gyro/fxas21002c_i2c.c
 create mode 100644 drivers/iio/gyro/fxas21002c_spi.c

-- 
2.21.0

[PATCH v5 1/6] iio: gyro: add DT bindings to fxas21002c

[Rui Miguel Silva]

Add device tree bindings for the FXAS21002C gyroscope.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 .../bindings/iio/gyroscope/nxp,fxas21002c.txt | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt

diff --git a/Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt b/Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
new file mode 100644
index 000000000000..465e104bbf14
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
@@ -0,0 +1,31 @@
+* NXP FXAS21002C Gyroscope device tree bindings
+
+http://www.nxp.com/products/sensors/gyroscopes/3-axis-digital-gyroscope:FXAS21002C
+
+Required properties:
+  - compatible : should be "nxp,fxas21002c"
+  - reg : the I2C address of the sensor or SPI chip select number for the
+          device.
+  - vdd-supply: phandle to the regulator that provides power to the sensor.
+  - vddio-supply: phandle to the regulator that provides power to the bus.
+
+Optional properties:
+  - reset-gpios : gpio used to reset the device, see gpio/gpio.txt
+  - interrupts : device support 2 interrupts, INT1 and INT2,
+                 the interrupts can be triggered on rising or falling edges.
+                 See interrupt-controller/interrupts.txt
+  - interrupt-names: should contain "INT1" or "INT2", the gyroscope interrupt
+                     line in use.
+  - drive-open-drain: the interrupt/data ready line will be configured
+                      as open drain, which is useful if several sensors share
+                      the same interrupt line. This is a boolean property.
+                      (This binding is taken from pinctrl/pinctrl-bindings.txt)
+
+Example:
+
+gyroscope@20 {
+	compatible = "nxp,fxas21002c";
+	reg = <0x20>;
+	vdd-supply = <&reg_peri_3p15v>;
+	vddio-supply = <&reg_peri_3p15v>;
+};
-- 
2.21.0

Re: [PATCH v5 1/6] iio: gyro: add DT bindings to fxas21002c

[Rob Herring]

On Tue, 26 Mar 2019 10:16:46 +0000, Rui Miguel Silva wrote:
> Add device tree bindings for the FXAS21002C gyroscope.
> 
> Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
> ---
>  .../bindings/iio/gyroscope/nxp,fxas21002c.txt | 31 +++++++++++++++++++
>  1 file changed, 31 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 1/6] iio: gyro: add DT bindings to fxas21002c

[Rob Herring]

On Tue, 26 Mar 2019 10:16:46 +0000, Rui Miguel Silva wrote:
> Add device tree bindings for the FXAS21002C gyroscope.
> 
> Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
> ---
>  .../bindings/iio/gyroscope/nxp,fxas21002c.txt | 31 +++++++++++++++++++
>  1 file changed, 31 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v5 2/6] iio: gyro: add core driver for fxas21002c

[Rui Miguel Silva]

Add core support for the NXP fxas21002c Tri-axis gyroscope,
using the iio subsystem. It supports PM operations, axis reading,
temperature, scale factor of the axis, high pass and low pass
filtering, and sampling frequency selection.

It will have extras modules to support the communication over i2c and
spi.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 drivers/iio/gyro/Kconfig           |   11 +
 drivers/iio/gyro/Makefile          |    1 +
 drivers/iio/gyro/fxas21002c.h      |  151 +++++
 drivers/iio/gyro/fxas21002c_core.c | 1006 ++++++++++++++++++++++++++++
 4 files changed, 1169 insertions(+)
 create mode 100644 drivers/iio/gyro/fxas21002c.h
 create mode 100644 drivers/iio/gyro/fxas21002c_core.c

diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
index 3126cf05e6b9..cfd2cf44bac8 100644
--- a/drivers/iio/gyro/Kconfig
+++ b/drivers/iio/gyro/Kconfig
@@ -73,6 +73,17 @@ config BMG160_SPI
 	tristate
 	select REGMAP_SPI
 
+config FXAS21002C
+       tristate "NXP FXAS21002C Gyro Sensor"
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
+       help
+         Say yes here to build support for NXP FXAS21002C Tri-axis Gyro
+         Sensor driver connected via I2C or SPI.
+
+         This driver can also be built as a module.  If so, the module
+         will be called fxas21002c_i2c or fxas21002c_spi.
+
 config HID_SENSOR_GYRO_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER
diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
index 295ec780c4eb..247dc600a602 100644
--- a/drivers/iio/gyro/Makefile
+++ b/drivers/iio/gyro/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_ADXRS450) += adxrs450.o
 obj-$(CONFIG_BMG160) += bmg160_core.o
 obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o
 obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o
+obj-$(CONFIG_FXAS21002C) += fxas21002c_core.o
 
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
 
diff --git a/drivers/iio/gyro/fxas21002c.h b/drivers/iio/gyro/fxas21002c.h
new file mode 100644
index 000000000000..e21fd410950c
--- /dev/null
+++ b/drivers/iio/gyro/fxas21002c.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Driver for NXP FXAS21002C Gyroscope - Header
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ *
+ */
+
+#ifndef FXAS21002C_H_
+#define FXAS21002C_H_
+
+#include <linux/regmap.h>
+
+#define FXAS21002C_REG_STATUS		0x00
+#define FXAS21002C_REG_OUT_X_MSB	0x01
+#define FXAS21002C_REG_OUT_X_LSB	0x02
+#define FXAS21002C_REG_OUT_Y_MSB	0x03
+#define FXAS21002C_REG_OUT_Y_LSB	0x04
+#define FXAS21002C_REG_OUT_Z_MSB	0x05
+#define FXAS21002C_REG_OUT_Z_LSB	0x06
+#define FXAS21002C_REG_DR_STATUS	0x07
+#define FXAS21002C_REG_F_STATUS		0x08
+#define FXAS21002C_REG_F_SETUP		0x09
+#define FXAS21002C_REG_F_EVENT		0x0A
+#define FXAS21002C_REG_INT_SRC_FLAG	0x0B
+#define FXAS21002C_REG_WHO_AM_I		0x0C
+#define FXAS21002C_REG_CTRL0		0x0D
+#define FXAS21002C_REG_RT_CFG		0x0E
+#define FXAS21002C_REG_RT_SRC		0x0F
+#define FXAS21002C_REG_RT_THS		0x10
+#define FXAS21002C_REG_RT_COUNT		0x11
+#define FXAS21002C_REG_TEMP		0x12
+#define FXAS21002C_REG_CTRL1		0x13
+#define FXAS21002C_REG_CTRL2		0x14
+#define FXAS21002C_REG_CTRL3		0x15
+
+enum fxas21002c_fields {
+	F_DR_STATUS,
+	F_OUT_X_MSB,
+	F_OUT_X_LSB,
+	F_OUT_Y_MSB,
+	F_OUT_Y_LSB,
+	F_OUT_Z_MSB,
+	F_OUT_Z_LSB,
+	/* DR_STATUS */
+	F_ZYX_OW, F_Z_OW, F_Y_OW, F_X_OW, F_ZYX_DR, F_Z_DR, F_Y_DR, F_X_DR,
+	/* F_STATUS */
+	F_OVF, F_WMKF, F_CNT,
+	/* F_SETUP */
+	F_MODE, F_WMRK,
+	/* F_EVENT */
+	F_EVENT, FE_TIME,
+	/* INT_SOURCE_FLAG */
+	F_BOOTEND, F_SRC_FIFO, F_SRC_RT, F_SRC_DRDY,
+	/* WHO_AM_I */
+	F_WHO_AM_I,
+	/* CTRL_REG0 */
+	F_BW, F_SPIW, F_SEL, F_HPF_EN, F_FS,
+	/* RT_CFG */
+	F_ELE, F_ZTEFE, F_YTEFE, F_XTEFE,
+	/* RT_SRC */
+	F_EA, F_ZRT, F_ZRT_POL, F_YRT, F_YRT_POL, F_XRT, F_XRT_POL,
+	/* RT_THS */
+	F_DBCNTM, F_THS,
+	/* RT_COUNT */
+	F_RT_COUNT,
+	/* TEMP */
+	F_TEMP,
+	/* CTRL_REG1 */
+	F_RST, F_ST, F_DR, F_ACTIVE, F_READY,
+	/* CTRL_REG2 */
+	F_INT_CFG_FIFO, F_INT_EN_FIFO, F_INT_CFG_RT, F_INT_EN_RT,
+	F_INT_CFG_DRDY, F_INT_EN_DRDY, F_IPOL, F_PP_OD,
+	/* CTRL_REG3 */
+	F_WRAPTOONE, F_EXTCTRLEN, F_FS_DOUBLE,
+	/* MAX FIELDS */
+	F_MAX_FIELDS,
+};
+
+static const struct reg_field fxas21002c_reg_fields[] = {
+	[F_DR_STATUS]		= REG_FIELD(FXAS21002C_REG_STATUS, 0, 7),
+	[F_OUT_X_MSB]		= REG_FIELD(FXAS21002C_REG_OUT_X_MSB, 0, 7),
+	[F_OUT_X_LSB]		= REG_FIELD(FXAS21002C_REG_OUT_X_LSB, 0, 7),
+	[F_OUT_Y_MSB]		= REG_FIELD(FXAS21002C_REG_OUT_Y_MSB, 0, 7),
+	[F_OUT_Y_LSB]		= REG_FIELD(FXAS21002C_REG_OUT_Y_LSB, 0, 7),
+	[F_OUT_Z_MSB]		= REG_FIELD(FXAS21002C_REG_OUT_Z_MSB, 0, 7),
+	[F_OUT_Z_LSB]		= REG_FIELD(FXAS21002C_REG_OUT_Z_LSB, 0, 7),
+	[F_ZYX_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 7, 7),
+	[F_Z_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 6, 6),
+	[F_Y_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 5, 5),
+	[F_X_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 4, 4),
+	[F_ZYX_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 3, 3),
+	[F_Z_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 2, 2),
+	[F_Y_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 1, 1),
+	[F_X_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 0, 0),
+	[F_OVF]			= REG_FIELD(FXAS21002C_REG_F_STATUS, 7, 7),
+	[F_WMKF]		= REG_FIELD(FXAS21002C_REG_F_STATUS, 6, 6),
+	[F_CNT]			= REG_FIELD(FXAS21002C_REG_F_STATUS, 0, 5),
+	[F_MODE]		= REG_FIELD(FXAS21002C_REG_F_SETUP, 6, 7),
+	[F_WMRK]		= REG_FIELD(FXAS21002C_REG_F_SETUP, 0, 5),
+	[F_EVENT]		= REG_FIELD(FXAS21002C_REG_F_EVENT, 5, 5),
+	[FE_TIME]		= REG_FIELD(FXAS21002C_REG_F_EVENT, 0, 4),
+	[F_BOOTEND]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 3, 3),
+	[F_SRC_FIFO]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 2, 2),
+	[F_SRC_RT]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 1, 1),
+	[F_SRC_DRDY]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 0, 0),
+	[F_WHO_AM_I]		= REG_FIELD(FXAS21002C_REG_WHO_AM_I, 0, 7),
+	[F_BW]			= REG_FIELD(FXAS21002C_REG_CTRL0, 6, 7),
+	[F_SPIW]		= REG_FIELD(FXAS21002C_REG_CTRL0, 5, 5),
+	[F_SEL]			= REG_FIELD(FXAS21002C_REG_CTRL0, 3, 4),
+	[F_HPF_EN]		= REG_FIELD(FXAS21002C_REG_CTRL0, 2, 2),
+	[F_FS]			= REG_FIELD(FXAS21002C_REG_CTRL0, 0, 1),
+	[F_ELE]			= REG_FIELD(FXAS21002C_REG_RT_CFG, 3, 3),
+	[F_ZTEFE]		= REG_FIELD(FXAS21002C_REG_RT_CFG, 2, 2),
+	[F_YTEFE]		= REG_FIELD(FXAS21002C_REG_RT_CFG, 1, 1),
+	[F_XTEFE]		= REG_FIELD(FXAS21002C_REG_RT_CFG, 0, 0),
+	[F_EA]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 6, 6),
+	[F_ZRT]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 5, 5),
+	[F_ZRT_POL]		= REG_FIELD(FXAS21002C_REG_RT_SRC, 4, 4),
+	[F_YRT]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 3, 3),
+	[F_YRT_POL]		= REG_FIELD(FXAS21002C_REG_RT_SRC, 2, 2),
+	[F_XRT]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 1, 1),
+	[F_XRT_POL]		= REG_FIELD(FXAS21002C_REG_RT_SRC, 0, 0),
+	[F_DBCNTM]		= REG_FIELD(FXAS21002C_REG_RT_THS, 7, 7),
+	[F_THS]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 0, 6),
+	[F_RT_COUNT]		= REG_FIELD(FXAS21002C_REG_RT_COUNT, 0, 7),
+	[F_TEMP]		= REG_FIELD(FXAS21002C_REG_TEMP, 0, 7),
+	[F_RST]			= REG_FIELD(FXAS21002C_REG_CTRL1, 6, 6),
+	[F_ST]			= REG_FIELD(FXAS21002C_REG_CTRL1, 5, 5),
+	[F_DR]			= REG_FIELD(FXAS21002C_REG_CTRL1, 2, 4),
+	[F_ACTIVE]		= REG_FIELD(FXAS21002C_REG_CTRL1, 1, 1),
+	[F_READY]		= REG_FIELD(FXAS21002C_REG_CTRL1, 0, 0),
+	[F_INT_CFG_FIFO]	= REG_FIELD(FXAS21002C_REG_CTRL2, 7, 7),
+	[F_INT_EN_FIFO]		= REG_FIELD(FXAS21002C_REG_CTRL2, 6, 6),
+	[F_INT_CFG_RT]		= REG_FIELD(FXAS21002C_REG_CTRL2, 5, 5),
+	[F_INT_EN_RT]		= REG_FIELD(FXAS21002C_REG_CTRL2, 4, 4),
+	[F_INT_CFG_DRDY]	= REG_FIELD(FXAS21002C_REG_CTRL2, 3, 3),
+	[F_INT_EN_DRDY]		= REG_FIELD(FXAS21002C_REG_CTRL2, 2, 2),
+	[F_IPOL]		= REG_FIELD(FXAS21002C_REG_CTRL2, 1, 1),
+	[F_PP_OD]		= REG_FIELD(FXAS21002C_REG_CTRL2, 0, 0),
+	[F_WRAPTOONE]		= REG_FIELD(FXAS21002C_REG_CTRL3, 3, 3),
+	[F_EXTCTRLEN]		= REG_FIELD(FXAS21002C_REG_CTRL3, 2, 2),
+	[F_FS_DOUBLE]		= REG_FIELD(FXAS21002C_REG_CTRL3, 0, 0),
+};
+
+extern const struct dev_pm_ops fxas21002c_pm_ops;
+
+int fxas21002c_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			  const char *name);
+void fxas21002c_core_remove(struct device *dev);
+#endif
diff --git a/drivers/iio/gyro/fxas21002c_core.c b/drivers/iio/gyro/fxas21002c_core.c
new file mode 100644
index 000000000000..1f41e450ecb7
--- /dev/null
+++ b/drivers/iio/gyro/fxas21002c_core.c
@@ -0,0 +1,1006 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for NXP FXAS21002C Gyroscope - Core
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include "fxas21002c.h"
+
+#define FXAS21002C_CHIP_ID_1	0xD6
+#define FXAS21002C_CHIP_ID_2	0xD7
+
+enum fxas21002c_mode_state {
+	FXAS21002C_MODE_STANDBY,
+	FXAS21002C_MODE_READY,
+	FXAS21002C_MODE_ACTIVE,
+};
+
+#define FXAS21002C_STANDBY_ACTIVE_TIME_MS	62
+#define FXAS21002C_READY_ACTIVE_TIME_MS		7
+
+#define FXAS21002C_ODR_LIST_MAX		10
+
+#define FXAS21002C_SCALE_FRACTIONAL	32
+#define FXAS21002C_RANGE_LIMIT_DOUBLE	2000
+
+#define FXAS21002C_AXIS_TO_REG(axis) (FXAS21002C_REG_OUT_X_MSB + ((axis) * 2))
+
+static const int fxas21002c_odr_values[] = {
+	800, 400, 200, 100, 50, 25, 12, 12
+};
+
+/*
+ * These values are taken from the low-pass filter cutoff frequency calculated
+ * ODR * 0.lpf_values. So, for ODR = 800Hz with a lpf value = 0.32
+ * => LPF cutoff frequency = 800 * 0.32 = 256 Hz
+ */
+static const int fxas21002c_lpf_values[] = {
+	32, 16, 8
+};
+
+/*
+ * These values are taken from the high-pass filter cutoff frequency calculated
+ * ODR * 0.0hpf_values. So, for ODR = 800Hz with a hpf value = 0.018750
+ * => HPF cutoff frequency = 800 * 0.018750 = 15 Hz
+ */
+static const int fxas21002c_hpf_values[] = {
+	18750, 9625, 4875, 2475
+};
+
+static const int fxas21002c_range_values[] = {
+	4000, 2000, 1000, 500, 250
+};
+
+struct fxas21002c_data {
+	u8 chip_id;
+	enum fxas21002c_mode_state mode;
+	enum fxas21002c_mode_state prev_mode;
+
+	struct mutex lock;		/* serialize data access */
+	struct regmap *regmap;
+	struct regmap_field *regmap_fields[F_MAX_FIELDS];
+	struct iio_trigger *dready_trig;
+	int irq;
+
+	struct regulator *vdd;
+	struct regulator *vddio;
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	s16 buffer[8] ____cacheline_aligned;
+};
+
+enum fxas21002c_channel_index {
+	CHANNEL_SCAN_INDEX_X,
+	CHANNEL_SCAN_INDEX_Y,
+	CHANNEL_SCAN_INDEX_Z,
+	CHANNEL_SCAN_MAX,
+};
+
+static int fxas21002c_odr_hz_from_value(struct fxas21002c_data *data, u8 value)
+{
+	int odr_value_max = ARRAY_SIZE(fxas21002c_odr_values) - 1;
+
+	value = min_t(u8, value, odr_value_max);
+
+	return fxas21002c_odr_values[value];
+}
+
+static int fxas21002c_odr_value_from_hz(struct fxas21002c_data *data,
+					unsigned int hz)
+{
+	int odr_table_size = ARRAY_SIZE(fxas21002c_odr_values);
+	int i;
+
+	for (i = 0; i < odr_table_size; i++)
+		if (fxas21002c_odr_values[i] == hz)
+			return i;
+
+	return -EINVAL;
+}
+
+static int fxas21002c_lpf_bw_from_value(struct fxas21002c_data *data, u8 value)
+{
+	int lpf_value_max = ARRAY_SIZE(fxas21002c_lpf_values) - 1;
+
+	value = min_t(u8, value, lpf_value_max);
+
+	return fxas21002c_lpf_values[value];
+}
+
+static int fxas21002c_lpf_value_from_bw(struct fxas21002c_data *data,
+					unsigned int hz)
+{
+	int lpf_table_size = ARRAY_SIZE(fxas21002c_lpf_values);
+	int i;
+
+	for (i = 0; i < lpf_table_size; i++)
+		if (fxas21002c_lpf_values[i] == hz)
+			return i;
+
+	return -EINVAL;
+}
+
+static int fxas21002c_hpf_sel_from_value(struct fxas21002c_data *data, u8 value)
+{
+	int hpf_value_max = ARRAY_SIZE(fxas21002c_hpf_values) - 1;
+
+	value = min_t(u8, value, hpf_value_max);
+
+	return fxas21002c_hpf_values[value];
+}
+
+static int fxas21002c_hpf_value_from_sel(struct fxas21002c_data *data,
+					 unsigned int hz)
+{
+	int hpf_table_size = ARRAY_SIZE(fxas21002c_hpf_values);
+	int i;
+
+	for (i = 0; i < hpf_table_size; i++)
+		if (fxas21002c_hpf_values[i] == hz)
+			return i;
+
+	return -EINVAL;
+}
+
+static int fxas21002c_range_fs_from_value(struct fxas21002c_data *data,
+					  u8 value)
+{
+	int range_value_max = ARRAY_SIZE(fxas21002c_range_values) - 1;
+	unsigned int fs_double;
+	int ret;
+
+	/* We need to check if FS_DOUBLE is enabled to offset the value */
+	ret = regmap_field_read(data->regmap_fields[F_FS_DOUBLE], &fs_double);
+	if (ret < 0)
+		return ret;
+
+	if (!fs_double)
+		value += 1;
+
+	value = min_t(u8, value, range_value_max);
+
+	return fxas21002c_range_values[value];
+}
+
+static int fxas21002c_range_value_from_fs(struct fxas21002c_data *data,
+					  unsigned int range)
+{
+	int range_table_size = ARRAY_SIZE(fxas21002c_range_values);
+	bool found = false;
+	int fs_double = 0;
+	int ret;
+	int i;
+
+	for (i = 0; i < range_table_size; i++)
+		if (fxas21002c_range_values[i] == range) {
+			found = true;
+			break;
+		}
+
+	if (!found)
+		return -EINVAL;
+
+	if (range > FXAS21002C_RANGE_LIMIT_DOUBLE)
+		fs_double = 1;
+
+	ret = regmap_field_write(data->regmap_fields[F_FS_DOUBLE], fs_double);
+	if (ret < 0)
+		return ret;
+
+	return i;
+}
+
+static int fxas21002c_mode_get(struct fxas21002c_data *data)
+{
+	unsigned int active;
+	unsigned int ready;
+	int ret;
+
+	ret = regmap_field_read(data->regmap_fields[F_ACTIVE], &active);
+	if (ret < 0)
+		return ret;
+	if (active)
+		return FXAS21002C_MODE_ACTIVE;
+
+	ret = regmap_field_read(data->regmap_fields[F_READY], &ready);
+	if (ret < 0)
+		return ret;
+	if (ready)
+		return FXAS21002C_MODE_READY;
+
+	return FXAS21002C_MODE_STANDBY;
+}
+
+static int fxas21002c_mode_set(struct fxas21002c_data *data,
+			       enum fxas21002c_mode_state mode)
+{
+	int ret;
+
+	if (mode == data->mode)
+		return 0;
+
+	if (mode == FXAS21002C_MODE_READY)
+		ret = regmap_field_write(data->regmap_fields[F_READY], 1);
+	else
+		ret = regmap_field_write(data->regmap_fields[F_READY], 0);
+	if (ret < 0)
+		return ret;
+
+	if (mode == FXAS21002C_MODE_ACTIVE)
+		ret = regmap_field_write(data->regmap_fields[F_ACTIVE], 1);
+	else
+		ret = regmap_field_write(data->regmap_fields[F_ACTIVE], 0);
+	if (ret < 0)
+		return ret;
+
+	/* if going to active wait the setup times */
+	if (mode == FXAS21002C_MODE_ACTIVE &&
+	    data->mode == FXAS21002C_MODE_STANDBY)
+		msleep_interruptible(FXAS21002C_STANDBY_ACTIVE_TIME_MS);
+
+	if (data->mode == FXAS21002C_MODE_READY)
+		msleep_interruptible(FXAS21002C_READY_ACTIVE_TIME_MS);
+
+	data->prev_mode = data->mode;
+	data->mode = mode;
+
+	return ret;
+}
+
+static int fxas21002c_write(struct fxas21002c_data *data,
+			    enum fxas21002c_fields field, int bits)
+{
+	int actual_mode;
+	int ret;
+
+	mutex_lock(&data->lock);
+
+	actual_mode = fxas21002c_mode_get(data);
+	if (actual_mode < 0) {
+		ret = actual_mode;
+		goto out_unlock;
+	}
+
+	ret = fxas21002c_mode_set(data, FXAS21002C_MODE_READY);
+	if (ret < 0)
+		goto out_unlock;
+
+	ret = regmap_field_write(data->regmap_fields[field], bits);
+	if (ret < 0)
+		goto out_unlock;
+
+	ret = fxas21002c_mode_set(data, data->prev_mode);
+
+out_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int  fxas21002c_pm_get(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		pm_runtime_put_noidle(dev);
+
+	return ret;
+}
+
+static int  fxas21002c_pm_put(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+
+	pm_runtime_mark_last_busy(dev);
+
+	return pm_runtime_put_autosuspend(dev);
+}
+
+static int fxas21002c_temp_get(struct fxas21002c_data *data, int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int temp;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = fxas21002c_pm_get(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = regmap_field_read(data->regmap_fields[F_TEMP], &temp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read temp: %d\n", ret);
+		goto data_unlock;
+	}
+
+	*val = sign_extend32(temp, 7);
+
+	ret = fxas21002c_pm_put(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = IIO_VAL_INT;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_axis_get(struct fxas21002c_data *data,
+			       int index, int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	__be16 axis_be;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = fxas21002c_pm_get(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = regmap_bulk_read(data->regmap, FXAS21002C_AXIS_TO_REG(index),
+			       &axis_be, sizeof(axis_be));
+	if (ret < 0) {
+		dev_err(dev, "failed to read axis: %d: %d\n", index, ret);
+		goto data_unlock;
+	}
+
+	*val = sign_extend32(be16_to_cpu(axis_be), 15);
+
+	ret = fxas21002c_pm_put(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = IIO_VAL_INT;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_odr_get(struct fxas21002c_data *data, int *odr)
+{
+	unsigned int odr_bits;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_DR], &odr_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	*odr = fxas21002c_odr_hz_from_value(data, odr_bits);
+
+	ret = IIO_VAL_INT;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_odr_set(struct fxas21002c_data *data, int odr)
+{
+	int odr_bits;
+
+	odr_bits = fxas21002c_odr_value_from_hz(data, odr);
+	if (odr_bits < 0)
+		return odr_bits;
+
+	return fxas21002c_write(data, F_DR, odr_bits);
+}
+
+static int fxas21002c_lpf_get(struct fxas21002c_data *data, int *val2)
+{
+	unsigned int bw_bits;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_BW], &bw_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	*val2 = fxas21002c_lpf_bw_from_value(data, bw_bits) * 10000;
+
+	ret = IIO_VAL_INT_PLUS_MICRO;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_lpf_set(struct fxas21002c_data *data, int bw)
+{
+	int bw_bits;
+	int odr;
+	int ret;
+
+	bw_bits = fxas21002c_lpf_value_from_bw(data, bw);
+	if (bw_bits < 0)
+		return bw_bits;
+
+	/*
+	 * From table 33 of the device spec, for ODR = 25Hz and 12.5 value 0.08
+	 * is not allowed and for ODR = 12.5 value 0.16 is also not allowed
+	 */
+	ret = fxas21002c_odr_get(data, &odr);
+	if (ret < 0)
+		return -EINVAL;
+
+	if ((odr == 25 && bw_bits > 0x01) || (odr == 12 && bw_bits > 0))
+		return -EINVAL;
+
+	return fxas21002c_write(data, F_BW, bw_bits);
+}
+
+static int fxas21002c_hpf_get(struct fxas21002c_data *data, int *val2)
+{
+	unsigned int sel_bits;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_SEL], &sel_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	*val2 = fxas21002c_hpf_sel_from_value(data, sel_bits);
+
+	ret = IIO_VAL_INT_PLUS_MICRO;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_hpf_set(struct fxas21002c_data *data, int sel)
+{
+	int sel_bits;
+
+	sel_bits = fxas21002c_hpf_value_from_sel(data, sel);
+	if (sel_bits < 0)
+		return sel_bits;
+
+	return fxas21002c_write(data, F_SEL, sel_bits);
+}
+
+static int fxas21002c_scale_get(struct fxas21002c_data *data, int *val)
+{
+	int fs_bits;
+	int scale;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_FS], &fs_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	scale = fxas21002c_range_fs_from_value(data, fs_bits);
+	if (scale < 0) {
+		ret = scale;
+		goto data_unlock;
+	}
+
+	*val = scale;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_scale_set(struct fxas21002c_data *data, int range)
+{
+	int fs_bits;
+
+	fs_bits = fxas21002c_range_value_from_fs(data, range);
+	if (fs_bits < 0)
+		return fs_bits;
+
+	return fxas21002c_write(data, F_FS, fs_bits);
+}
+
+static int fxas21002c_read_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan, int *val,
+			       int *val2, long mask)
+{
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return fxas21002c_temp_get(data, val);
+		case IIO_ANGL_VEL:
+			return fxas21002c_axis_get(data, chan->scan_index, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*val2 = FXAS21002C_SCALE_FRACTIONAL;
+			ret = fxas21002c_scale_get(data, val);
+			if (ret < 0)
+				return ret;
+
+			return IIO_VAL_FRACTIONAL;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		*val = 0;
+		return fxas21002c_lpf_get(data, val2);
+	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
+		*val = 0;
+		return fxas21002c_hpf_get(data, val2);
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val2 = 0;
+		return fxas21002c_odr_get(data, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int fxas21002c_write_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan, int val,
+				int val2, long mask)
+{
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	int range;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val2)
+			return -EINVAL;
+
+		return fxas21002c_odr_set(data, val);
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		if (val)
+			return -EINVAL;
+
+		val2 = val2 / 10000;
+		return fxas21002c_lpf_set(data, val2);
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			range = (((val * 1000 + val2 / 1000) *
+				  FXAS21002C_SCALE_FRACTIONAL) / 1000);
+			return fxas21002c_scale_set(data, range);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
+		return fxas21002c_hpf_set(data, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("12.5 25 50 100 200 400 800");
+
+static IIO_CONST_ATTR(in_anglvel_filter_low_pass_3db_frequency_available,
+		      "0.32 0.16 0.08");
+
+static IIO_CONST_ATTR(in_anglvel_filter_high_pass_3db_frequency_available,
+		      "0.018750 0.009625 0.004875 0.002475");
+
+static IIO_CONST_ATTR(in_anglvel_scale_available,
+		      "125.0 62.5 31.25 15.625 7.8125");
+
+static struct attribute *fxas21002c_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_const_attr_in_anglvel_filter_low_pass_3db_frequency_available.dev_attr.attr,
+	&iio_const_attr_in_anglvel_filter_high_pass_3db_frequency_available.dev_attr.attr,
+	&iio_const_attr_in_anglvel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group fxas21002c_attrs_group = {
+	.attrs = fxas21002c_attributes,
+};
+
+#define FXAS21002C_CHANNEL(_axis) {					\
+	.type = IIO_ANGL_VEL,						\
+	.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) |	\
+		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
+	.scan_index = CHANNEL_SCAN_INDEX_##_axis,			\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 16,						\
+		.storagebits = 16,					\
+		.endianness = IIO_BE,					\
+	},								\
+}
+
+static const struct iio_chan_spec fxas21002c_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = -1,
+	},
+	FXAS21002C_CHANNEL(X),
+	FXAS21002C_CHANNEL(Y),
+	FXAS21002C_CHANNEL(Z),
+};
+
+static const struct iio_info fxas21002c_info = {
+	.attrs			= &fxas21002c_attrs_group,
+	.read_raw		= &fxas21002c_read_raw,
+	.write_raw		= &fxas21002c_write_raw,
+};
+
+static irqreturn_t fxas21002c_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_bulk_read(data->regmap, FXAS21002C_REG_OUT_X_MSB,
+			       data->buffer, CHANNEL_SCAN_MAX * sizeof(s16));
+	mutex_unlock(&data->lock);
+	if (ret < 0)
+		goto notify_done;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   pf->timestamp);
+
+notify_done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int fxas21002c_chip_init(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int chip_id;
+	int ret;
+
+	ret = regmap_field_read(data->regmap_fields[F_WHO_AM_I], &chip_id);
+	if (ret < 0)
+		return ret;
+
+	if (chip_id != FXAS21002C_CHIP_ID_1 &&
+	    chip_id != FXAS21002C_CHIP_ID_2) {
+		dev_err(dev, "chip id 0x%02x is not supported\n", chip_id);
+		return -EINVAL;
+	}
+
+	data->chip_id = chip_id;
+
+	ret = fxas21002c_mode_set(data, FXAS21002C_MODE_STANDBY);
+	if (ret < 0)
+		return ret;
+
+	/* Set ODR to 200HZ as default */
+	ret = fxas21002c_odr_set(data, 200);
+	if (ret < 0)
+		dev_err(dev, "failed to set ODR: %d\n", ret);
+
+	return ret;
+}
+
+static int fxas21002c_data_rdy_trigger_set_state(struct iio_trigger *trig,
+						 bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+
+	return regmap_field_write(data->regmap_fields[F_INT_EN_DRDY], state);
+}
+
+static const struct iio_trigger_ops fxas21002c_trigger_ops = {
+	.set_trigger_state = &fxas21002c_data_rdy_trigger_set_state,
+};
+
+static irqreturn_t fxas21002c_data_rdy_trig_poll(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	unsigned int data_ready;
+	int ret;
+
+	ret = regmap_field_read(data->regmap_fields[F_SRC_DRDY], &data_ready);
+	if (ret < 0)
+		return IRQ_NONE;
+
+	if (!data_ready)
+		return IRQ_NONE;
+
+	iio_trigger_poll(data->dready_trig);
+
+	return IRQ_HANDLED;
+}
+
+static int fxas21002c_trigger_probe(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct device_node *np = indio_dev->dev.of_node;
+	unsigned long irq_trig;
+	bool irq_open_drain;
+	int irq1;
+	int ret;
+
+	if (!data->irq)
+		return 0;
+
+	irq1 = of_irq_get_byname(np, "INT1");
+
+	if (irq1 == data->irq) {
+		dev_info(dev, "using interrupt line INT1\n");
+		ret = regmap_field_write(data->regmap_fields[F_INT_CFG_DRDY],
+					 1);
+		if (ret < 0)
+			return ret;
+	}
+
+	dev_info(dev, "using interrupt line INT2\n");
+
+	irq_open_drain = of_property_read_bool(np, "drive-open-drain");
+
+	data->dready_trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+						   indio_dev->name,
+						   indio_dev->id);
+	if (!data->dready_trig)
+		return -ENOMEM;
+
+	irq_trig = irqd_get_trigger_type(irq_get_irq_data(data->irq));
+
+	if (irq_trig == IRQF_TRIGGER_RISING) {
+		ret = regmap_field_write(data->regmap_fields[F_IPOL], 1);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (irq_open_drain)
+		irq_trig |= IRQF_SHARED;
+
+	ret = devm_request_irq(dev, data->irq, fxas21002c_data_rdy_trig_poll,
+			       irq_trig, "fxas21002c_data_ready",
+			       data->dready_trig);
+	if (ret < 0)
+		return ret;
+
+	data->dready_trig->dev.parent = dev;
+	data->dready_trig->ops = &fxas21002c_trigger_ops;
+	iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+
+	return iio_trigger_register(data->dready_trig);
+}
+
+static int fxas21002c_power_enable(struct fxas21002c_data *data)
+{
+	int ret;
+
+	ret = regulator_enable(data->vdd);
+	if (ret < 0)
+		return ret;
+
+	ret = regulator_enable(data->vddio);
+	if (ret < 0) {
+		regulator_disable(data->vdd);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void fxas21002c_power_disable(struct fxas21002c_data *data)
+{
+	regulator_disable(data->vdd);
+	regulator_disable(data->vddio);
+}
+
+static void fxas21002c_power_disable_action(void *_data)
+{
+	struct fxas21002c_data *data = _data;
+
+	fxas21002c_power_disable(data);
+}
+
+static int fxas21002c_regulators_get(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+
+	data->vdd = devm_regulator_get(dev->parent, "vdd");
+	if (IS_ERR(data->vdd))
+		return PTR_ERR(data->vdd);
+
+	data->vddio = devm_regulator_get(dev->parent, "vddio");
+	if (IS_ERR(data->vddio))
+		return PTR_ERR(data->vddio);
+
+	return 0;
+}
+
+int fxas21002c_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			  const char *name)
+{
+	struct fxas21002c_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap_field *f;
+	int i;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
+	data->irq = irq;
+	data->regmap = regmap;
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		f = devm_regmap_field_alloc(dev, data->regmap,
+					    fxas21002c_reg_fields[i]);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+
+		data->regmap_fields[i] = f;
+	}
+
+	mutex_init(&data->lock);
+
+	ret = fxas21002c_regulators_get(data);
+	if (ret < 0)
+		return ret;
+
+	ret = fxas21002c_power_enable(data);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, fxas21002c_power_disable_action,
+				       data);
+	if (ret < 0)
+		return ret;
+
+	ret = fxas21002c_chip_init(data);
+	if (ret < 0)
+		return ret;
+
+	indio_dev->dev.parent = dev;
+	indio_dev->channels = fxas21002c_channels;
+	indio_dev->num_channels = ARRAY_SIZE(fxas21002c_channels);
+	indio_dev->name = name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &fxas21002c_info;
+
+	ret = fxas21002c_trigger_probe(data);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
+					 fxas21002c_trigger_handler, NULL);
+	if (ret < 0)
+		goto trigger_unregister;
+
+	ret = pm_runtime_set_active(dev);
+	if (ret)
+		goto buffer_cleanup;
+
+	pm_runtime_enable(dev);
+	pm_runtime_set_autosuspend_delay(dev, 2000);
+	pm_runtime_use_autosuspend(dev);
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto pm_disable;
+
+	return 0;
+
+pm_disable:
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+
+buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+trigger_unregister:
+	if (data->irq)
+		iio_trigger_unregister(data->dready_trig);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fxas21002c_core_probe);
+
+void fxas21002c_core_remove(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+
+	iio_triggered_buffer_cleanup(indio_dev);
+
+	if (data->irq)
+		iio_trigger_unregister(data->dready_trig);
+	fxas21002c_power_disable(data);
+}
+EXPORT_SYMBOL_GPL(fxas21002c_core_remove);
+
+static int __maybe_unused fxas21002c_suspend(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+
+	fxas21002c_mode_set(data, FXAS21002C_MODE_STANDBY);
+	fxas21002c_power_disable(data);
+
+	return 0;
+}
+
+static int __maybe_unused fxas21002c_resume(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+	int ret;
+
+	ret = fxas21002c_power_enable(data);
+	if (ret < 0)
+		return ret;
+
+	return fxas21002c_mode_set(data, data->prev_mode);
+}
+
+static int __maybe_unused fxas21002c_runtime_suspend(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return fxas21002c_mode_set(data, FXAS21002C_MODE_READY);
+}
+
+static int __maybe_unused fxas21002c_runtime_resume(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return fxas21002c_mode_set(data, FXAS21002C_MODE_ACTIVE);
+}
+
+const struct dev_pm_ops fxas21002c_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(fxas21002c_suspend, fxas21002c_resume)
+	SET_RUNTIME_PM_OPS(fxas21002c_runtime_suspend,
+			   fxas21002c_runtime_resume, NULL)
+};
+EXPORT_SYMBOL_GPL(fxas21002c_pm_ops);
+
+MODULE_AUTHOR("Rui Miguel Silva <rui.silva@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("FXAS21002C Gyro driver");
-- 
2.21.0

Re: [PATCH v5 2/6] iio: gyro: add core driver for fxas21002c

[Jonathan Cameron]

On Tue, 26 Mar 2019 10:16:47 +0000
Rui Miguel Silva <rui.silva@linaro.org> wrote:

> Add core support for the NXP fxas21002c Tri-axis gyroscope,
> using the iio subsystem. It supports PM operations, axis reading,
> temperature, scale factor of the axis, high pass and low pass
> filtering, and sampling frequency selection.
> 
> It will have extras modules to support the communication over i2c and
> spi.
> 
> Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Ah, slightly missunderstanding around what I suggested for probe / remove
ordering.  I've marked it inline and would have just fixed it whilst applying
but there is another issue inline that I had missed before.


> ---
>  drivers/iio/gyro/Kconfig           |   11 +
>  drivers/iio/gyro/Makefile          |    1 +
>  drivers/iio/gyro/fxas21002c.h      |  151 +++++
>  drivers/iio/gyro/fxas21002c_core.c | 1006 ++++++++++++++++++++++++++++
>  4 files changed, 1169 insertions(+)
>  create mode 100644 drivers/iio/gyro/fxas21002c.h
>  create mode 100644 drivers/iio/gyro/fxas21002c_core.c
> 
> diff --git a/drivers/iio/gyro/fxas21002c.h b/drivers/iio/gyro/fxas21002c.h
> new file mode 100644
> index 000000000000..e21fd410950c
> --- /dev/null
> +++ b/drivers/iio/gyro/fxas21002c.h
> @@ -0,0 +1,151 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Driver for NXP FXAS21002C Gyroscope - Header
> + *
> + * Copyright (C) 2019 Linaro Ltd.
> + *

I'm a stickler for hanging blank lines.  So drop this one.
> + */
> +
> +#ifndef FXAS21002C_H_
> +#define FXAS21002C_H_
...

> +
> +static irqreturn_t fxas21002c_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct fxas21002c_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->lock);
> +	ret = regmap_bulk_read(data->regmap, FXAS21002C_REG_OUT_X_MSB,
> +			       data->buffer, CHANNEL_SCAN_MAX * sizeof(s16));
> +	mutex_unlock(&data->lock);
A side note here.  Right now it's not possible to use data->buffer concurrently
so I'm not sure this lock is actually needed. In most drivers we also
end up using the same buffer for other accesses, but here it it is only
this one which is in a thread which can only be running once at a time IIRC.

Ah well, paranoid never hurt anyone ;)  I only got suspicious when I noticed
it didn't protect the buffer when it is still be used in the push_to_buffers
call below.

> +	if (ret < 0)
> +		goto notify_done;
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> +					   pf->timestamp);
> +
> +notify_done:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int fxas21002c_chip_init(struct fxas21002c_data *data)
> +{
> +	struct device *dev = regmap_get_device(data->regmap);
> +	unsigned int chip_id;
> +	int ret;
> +
> +	ret = regmap_field_read(data->regmap_fields[F_WHO_AM_I], &chip_id);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (chip_id != FXAS21002C_CHIP_ID_1 &&
> +	    chip_id != FXAS21002C_CHIP_ID_2) {
> +		dev_err(dev, "chip id 0x%02x is not supported\n", chip_id);
> +		return -EINVAL;
> +	}
> +
> +	data->chip_id = chip_id;
> +
> +	ret = fxas21002c_mode_set(data, FXAS21002C_MODE_STANDBY);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Set ODR to 200HZ as default */
> +	ret = fxas21002c_odr_set(data, 200);
> +	if (ret < 0)
> +		dev_err(dev, "failed to set ODR: %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static int fxas21002c_data_rdy_trigger_set_state(struct iio_trigger *trig,
> +						 bool state)
> +{
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct fxas21002c_data *data = iio_priv(indio_dev);
> +
> +	return regmap_field_write(data->regmap_fields[F_INT_EN_DRDY], state);
> +}
> +
> +static const struct iio_trigger_ops fxas21002c_trigger_ops = {
> +	.set_trigger_state = &fxas21002c_data_rdy_trigger_set_state,
> +};
> +
> +static irqreturn_t fxas21002c_data_rdy_trig_poll(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct fxas21002c_data *data = iio_priv(indio_dev);
> +	unsigned int data_ready;
> +	int ret;
> +
> +	ret = regmap_field_read(data->regmap_fields[F_SRC_DRDY], &data_ready);
> +	if (ret < 0)
> +		return IRQ_NONE;
> +
> +	if (!data_ready)
> +		return IRQ_NONE;
> +
> +	iio_trigger_poll(data->dready_trig);

This isn't right.  The function sleeps in the regmap_read above adn
iio_trigger_poll is to be called from an irq context. You want
iio_trigger_poll_chained (which is missnamed and I should fix that
one day - it should probably be _nested) which is the version
that only calls the thread parts.

https://elixir.bootlin.com/linux/latest/source/drivers/iio/industrialio-trigger.c#L189

The problem is that you are relying on the iio_pollfunc_store_time
top half which won't ever get called.  Easy fix though is to just
get the timestamp in your interrupt thread function directly.

> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int fxas21002c_trigger_probe(struct fxas21002c_data *data)
> +{
> +	struct device *dev = regmap_get_device(data->regmap);
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct device_node *np = indio_dev->dev.of_node;
> +	unsigned long irq_trig;
> +	bool irq_open_drain;
> +	int irq1;
> +	int ret;
> +
> +	if (!data->irq)
> +		return 0;
> +
> +	irq1 = of_irq_get_byname(np, "INT1");
> +
> +	if (irq1 == data->irq) {
> +		dev_info(dev, "using interrupt line INT1\n");
> +		ret = regmap_field_write(data->regmap_fields[F_INT_CFG_DRDY],
> +					 1);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	dev_info(dev, "using interrupt line INT2\n");
> +
> +	irq_open_drain = of_property_read_bool(np, "drive-open-drain");
> +
> +	data->dready_trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
> +						   indio_dev->name,
> +						   indio_dev->id);
> +	if (!data->dready_trig)
> +		return -ENOMEM;
> +
> +	irq_trig = irqd_get_trigger_type(irq_get_irq_data(data->irq));
> +
> +	if (irq_trig == IRQF_TRIGGER_RISING) {
> +		ret = regmap_field_write(data->regmap_fields[F_IPOL], 1);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	if (irq_open_drain)
> +		irq_trig |= IRQF_SHARED;
> +
> +	ret = devm_request_irq(dev, data->irq, fxas21002c_data_rdy_trig_poll,
> +			       irq_trig, "fxas21002c_data_ready",
> +			       data->dready_trig);
> +	if (ret < 0)
> +		return ret;
> +
> +	data->dready_trig->dev.parent = dev;
> +	data->dready_trig->ops = &fxas21002c_trigger_ops;
> +	iio_trigger_set_drvdata(data->dready_trig, indio_dev);
> +
> +	return iio_trigger_register(data->dready_trig);
You are fine using the devm version of this . See below.
> +}
> +
> +static int fxas21002c_power_enable(struct fxas21002c_data *data)
> +{
> +	int ret;
> +
> +	ret = regulator_enable(data->vdd);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regulator_enable(data->vddio);
> +	if (ret < 0) {
> +		regulator_disable(data->vdd);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void fxas21002c_power_disable(struct fxas21002c_data *data)
> +{
> +	regulator_disable(data->vdd);
> +	regulator_disable(data->vddio);
> +}
> +
> +static void fxas21002c_power_disable_action(void *_data)
> +{
> +	struct fxas21002c_data *data = _data;
> +
> +	fxas21002c_power_disable(data);
> +}
> +
> +static int fxas21002c_regulators_get(struct fxas21002c_data *data)
> +{
> +	struct device *dev = regmap_get_device(data->regmap);
> +
> +	data->vdd = devm_regulator_get(dev->parent, "vdd");
> +	if (IS_ERR(data->vdd))
> +		return PTR_ERR(data->vdd);
> +
> +	data->vddio = devm_regulator_get(dev->parent, "vddio");
> +	if (IS_ERR(data->vddio))
> +		return PTR_ERR(data->vddio);
> +
> +	return 0;
> +}
> +
> +int fxas21002c_core_probe(struct device *dev, struct regmap *regmap, int irq,
> +			  const char *name)
> +{
> +	struct fxas21002c_data *data;
> +	struct iio_dev *indio_dev;
> +	struct regmap_field *f;
> +	int i;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	dev_set_drvdata(dev, indio_dev);
> +	data->irq = irq;
> +	data->regmap = regmap;
> +
> +	for (i = 0; i < F_MAX_FIELDS; i++) {
> +		f = devm_regmap_field_alloc(dev, data->regmap,
> +					    fxas21002c_reg_fields[i]);
> +		if (IS_ERR(f))
> +			return PTR_ERR(f);
> +
> +		data->regmap_fields[i] = f;
> +	}
> +
> +	mutex_init(&data->lock);
> +
> +	ret = fxas21002c_regulators_get(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = fxas21002c_power_enable(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = devm_add_action_or_reset(dev, fxas21002c_power_disable_action,
> +				       data);
Good. This effectively makes up for us not having a devm_regulator_enable
so it will be automatically cleared up in remove or error paths.

> +	if (ret < 0)
> +		return ret;
> +
> +	ret = fxas21002c_chip_init(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->channels = fxas21002c_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(fxas21002c_channels);
> +	indio_dev->name = name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &fxas21002c_info;
> +
> +	ret = fxas21002c_trigger_probe(data);
> +	if (ret < 0)
> +		return ret;
This can still use the devm_iio_trigger_register internally so
doesn't need clearing up by hand.
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
> +					 fxas21002c_trigger_handler, NULL);
> +	if (ret < 0)
devm_iio_trigger_buffer_setup is fine.
Then return ret;
> +		goto trigger_unregister;
> +
> +	ret = pm_runtime_set_active(dev);
> +	if (ret)
> +		goto buffer_cleanup;
So this is the point where we now have to stop using devm_ based
cleanup if we want to maintain ordering.  So all correct from
here, but before here you are fine using devm.

> +
> +	pm_runtime_enable(dev);
> +	pm_runtime_set_autosuspend_delay(dev, 2000);
> +	pm_runtime_use_autosuspend(dev);
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0)
> +		goto pm_disable;
> +
> +	return 0;
> +
> +pm_disable:
> +	pm_runtime_disable(dev);
> +	pm_runtime_set_suspended(dev);
> +	pm_runtime_put_noidle(dev);
> +
> +buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
> +trigger_unregister:
> +	if (data->irq)
> +		iio_trigger_unregister(data->dready_trig);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(fxas21002c_core_probe);
> +
> +void fxas21002c_core_remove(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct fxas21002c_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	pm_runtime_disable(dev);
> +	pm_runtime_set_suspended(dev);
> +	pm_runtime_put_noidle(dev);
> +
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
> +	if (data->irq)
> +		iio_trigger_unregister(data->dready_trig);
> +	fxas21002c_power_disable(data);
This is handled by the devm_action_or_reset  in probe.

That will ensure that remove automatically calls this.
As a result there is no need to use non devm_ functions for
the next few. I'll clean it up when applying but please
check I didn't mess it up!

> +}
> +EXPORT_SYMBOL_GPL(fxas21002c_core_remove);
> +
> +static int __maybe_unused fxas21002c_suspend(struct device *dev)
> +{
> +	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
> +
> +	fxas21002c_mode_set(data, FXAS21002C_MODE_STANDBY);
> +	fxas21002c_power_disable(data);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused fxas21002c_resume(struct device *dev)
> +{
> +	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
> +	int ret;
> +
> +	ret = fxas21002c_power_enable(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	return fxas21002c_mode_set(data, data->prev_mode);
> +}
> +
> +static int __maybe_unused fxas21002c_runtime_suspend(struct device *dev)
> +{
> +	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
> +
> +	return fxas21002c_mode_set(data, FXAS21002C_MODE_READY);
> +}
> +
> +static int __maybe_unused fxas21002c_runtime_resume(struct device *dev)
> +{
> +	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
> +
> +	return fxas21002c_mode_set(data, FXAS21002C_MODE_ACTIVE);
> +}
> +
> +const struct dev_pm_ops fxas21002c_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(fxas21002c_suspend, fxas21002c_resume)
> +	SET_RUNTIME_PM_OPS(fxas21002c_runtime_suspend,
> +			   fxas21002c_runtime_resume, NULL)
> +};
> +EXPORT_SYMBOL_GPL(fxas21002c_pm_ops);
> +
> +MODULE_AUTHOR("Rui Miguel Silva <rui.silva@linaro.org>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("FXAS21002C Gyro driver");

[PATCH v5 3/6] iio: gyro: fxas21002c: add i2c driver

[Rui Miguel Silva]

Add the real driver to talk over i2c and use the fxas21002c core
for the main tasks.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 drivers/iio/gyro/Kconfig          |  6 +++
 drivers/iio/gyro/Makefile         |  1 +
 drivers/iio/gyro/fxas21002c_i2c.c | 69 +++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+)
 create mode 100644 drivers/iio/gyro/fxas21002c_i2c.c

diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
index cfd2cf44bac8..71b6552ee06b 100644
--- a/drivers/iio/gyro/Kconfig
+++ b/drivers/iio/gyro/Kconfig
@@ -77,6 +77,8 @@ config FXAS21002C
        tristate "NXP FXAS21002C Gyro Sensor"
        select IIO_BUFFER
        select IIO_TRIGGERED_BUFFER
+       select FXAS21002C_I2C if (I2C)
+       depends on I2C
        help
          Say yes here to build support for NXP FXAS21002C Tri-axis Gyro
          Sensor driver connected via I2C or SPI.
@@ -84,6 +86,10 @@ config FXAS21002C
          This driver can also be built as a module.  If so, the module
          will be called fxas21002c_i2c or fxas21002c_spi.
 
+config FXAS21002C_I2C
+       tristate
+       select REGMAP_I2C
+
 config HID_SENSOR_GYRO_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER
diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
index 247dc600a602..adc18a5eb283 100644
--- a/drivers/iio/gyro/Makefile
+++ b/drivers/iio/gyro/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_BMG160) += bmg160_core.o
 obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o
 obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o
 obj-$(CONFIG_FXAS21002C) += fxas21002c_core.o
+obj-$(CONFIG_FXAS21002C_I2C) += fxas21002c_i2c.o
 
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
 
diff --git a/drivers/iio/gyro/fxas21002c_i2c.c b/drivers/iio/gyro/fxas21002c_i2c.c
new file mode 100644
index 000000000000..a7807fd97483
--- /dev/null
+++ b/drivers/iio/gyro/fxas21002c_i2c.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for NXP FXAS21002C Gyroscope - I2C
+ *
+ * Copyright (C) 2018 Linaro Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "fxas21002c.h"
+
+static const struct regmap_config fxas21002c_regmap_i2c_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = FXAS21002C_REG_CTRL3,
+};
+
+static int fxas21002c_i2c_probe(struct i2c_client *i2c)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(i2c, &fxas21002c_regmap_i2c_conf);
+	if (IS_ERR(regmap)) {
+		dev_err(&i2c->dev, "Failed to register i2c regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return fxas21002c_core_probe(&i2c->dev, regmap, i2c->irq, i2c->name);
+}
+
+static int fxas21002c_i2c_remove(struct i2c_client *i2c)
+{
+	fxas21002c_core_remove(&i2c->dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id fxas21002c_i2c_id[] = {
+	{ "fxas21002c", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, fxas21002c_i2c_id);
+
+static const struct of_device_id fxas21002c_i2c_of_match[] = {
+	{ .compatible = "nxp,fxas21002c", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, fxas21002c_i2c_of_match);
+
+static struct i2c_driver fxas21002c_i2c_driver = {
+	.driver = {
+		.name = "fxas21002c_i2c",
+		.pm = &fxas21002c_pm_ops,
+		.of_match_table = fxas21002c_i2c_of_match,
+	},
+	.probe_new	= fxas21002c_i2c_probe,
+	.remove		= fxas21002c_i2c_remove,
+	.id_table	= fxas21002c_i2c_id,
+};
+module_i2c_driver(fxas21002c_i2c_driver);
+
+MODULE_AUTHOR("Rui Miguel Silva <rui.silva@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("FXAS21002C I2C Gyro driver");
-- 
2.21.0

[PATCH v5 4/6] iio: gyro: fxas21002c: add spi driver

[Rui Miguel Silva]

Add driver to talk over spi to a fxas21002c gyroscope device and use
the core as main controller.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 drivers/iio/gyro/Kconfig          |  7 +++-
 drivers/iio/gyro/Makefile         |  1 +
 drivers/iio/gyro/fxas21002c_spi.c | 70 +++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 drivers/iio/gyro/fxas21002c_spi.c

diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
index 71b6552ee06b..61c00cee037d 100644
--- a/drivers/iio/gyro/Kconfig
+++ b/drivers/iio/gyro/Kconfig
@@ -78,7 +78,8 @@ config FXAS21002C
        select IIO_BUFFER
        select IIO_TRIGGERED_BUFFER
        select FXAS21002C_I2C if (I2C)
-       depends on I2C
+       select FXAS21002C_SPI if (SPI)
+       depends on (I2C || SPI_MASTER)
        help
          Say yes here to build support for NXP FXAS21002C Tri-axis Gyro
          Sensor driver connected via I2C or SPI.
@@ -90,6 +91,10 @@ config FXAS21002C_I2C
        tristate
        select REGMAP_I2C
 
+config FXAS21002C_SPI
+       tristate
+       select REGMAP_SPI
+
 config HID_SENSOR_GYRO_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER
diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
index adc18a5eb283..45cbd5dc644e 100644
--- a/drivers/iio/gyro/Makefile
+++ b/drivers/iio/gyro/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o
 obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o
 obj-$(CONFIG_FXAS21002C) += fxas21002c_core.o
 obj-$(CONFIG_FXAS21002C_I2C) += fxas21002c_i2c.o
+obj-$(CONFIG_FXAS21002C_SPI) += fxas21002c_spi.o
 
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
 
diff --git a/drivers/iio/gyro/fxas21002c_spi.c b/drivers/iio/gyro/fxas21002c_spi.c
new file mode 100644
index 000000000000..77ceebef4e34
--- /dev/null
+++ b/drivers/iio/gyro/fxas21002c_spi.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for NXP Fxas21002c Gyroscope - SPI
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "fxas21002c.h"
+
+static const struct regmap_config fxas21002c_regmap_spi_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = FXAS21002C_REG_CTRL3,
+};
+
+static int fxas21002c_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &fxas21002c_regmap_spi_conf);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Failed to register spi regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return fxas21002c_core_probe(&spi->dev, regmap, spi->irq, id->name);
+}
+
+static int fxas21002c_spi_remove(struct spi_device *spi)
+{
+	fxas21002c_core_remove(&spi->dev);
+
+	return 0;
+}
+
+static const struct spi_device_id fxas21002c_spi_id[] = {
+	{ "fxas21002c", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, fxas21002c_spi_id);
+
+static const struct of_device_id fxas21002c_spi_of_match[] = {
+	{ .compatible = "nxp,fxas21002c", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, fxas21002c_spi_of_match);
+
+static struct spi_driver fxas21002c_spi_driver = {
+	.driver = {
+		.name = "fxas21002c_spi",
+		.pm = &fxas21002c_pm_ops,
+		.of_match_table = fxas21002c_spi_of_match,
+	},
+	.probe		= fxas21002c_spi_probe,
+	.remove		= fxas21002c_spi_remove,
+	.id_table	= fxas21002c_spi_id,
+};
+module_spi_driver(fxas21002c_spi_driver);
+
+MODULE_AUTHOR("Rui Miguel Silva <rui.silva@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("FXAS21002C SPI Gyro driver");
-- 
2.21.0

[PATCH v5 5/6] ARM: dts: imx7s-warp: add fxas21002c gyroscope

[Rui Miguel Silva]

Add entry to enable the fxas21002c gyroscope in the warp7 board.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 arch/arm/boot/dts/imx7s-warp.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/imx7s-warp.dts b/arch/arm/boot/dts/imx7s-warp.dts
index 23431faecaf4..c7dd66828a90 100644
--- a/arch/arm/boot/dts/imx7s-warp.dts
+++ b/arch/arm/boot/dts/imx7s-warp.dts
@@ -209,6 +209,13 @@
 		compatible = "fsl,mpl3115";
 		reg = <0x60>;
 	};
+
+	gyroscope@20 {
+		compatible = "nxp,fxas21002c";
+		reg = <0x20>;
+		vdd-supply = <&reg_peri_3p15v>;
+		vddio-supply = <&reg_peri_3p15v>;
+	};
 };
 
 &sai1 {
-- 
2.21.0

[PATCH v5 6/6] MAINTAINERS: add entry for fxas21002c gyro driver

[Rui Miguel Silva]

Add me as maintainer of the nxp fxas21002c gyroscope driver.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 MAINTAINERS | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index e17ebf70b548..2748e406889c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11107,6 +11107,16 @@ F:	Documentation/ABI/stable/sysfs-bus-nvmem
 F:	include/linux/nvmem-consumer.h
 F:	include/linux/nvmem-provider.h
 
+NXP FXAS21002C DRIVER
+M:	Rui Miguel Silva <rmfrfs@gmail.com>
+L:	linux-iio@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/gyroscope/fxas21002c.txt
+F:	drivers/iio/gyro/fxas21002c_core.c
+F:	drivers/iio/gyro/fxas21002c.h
+F:	drivers/iio/gyro/fxas21002c_i2c.c
+F:	drivers/iio/gyro/fxas21002c_spi.c
+
 NXP SGTL5000 DRIVER
 M:	Fabio Estevam <festevam@gmail.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
-- 
2.21.0

Re: [PATCH v5 0/6] iio: gyro: add fxas21002c driver

[Jonathan Cameron]

On Tue, 26 Mar 2019 10:16:45 +0000
Rui Miguel Silva <rui.silva@linaro.org> wrote:

> Hi,
> This series introduce a NXP fxas21002c tri axis gyroscope driver [0]
> It add a core implementaiton plus an i2c and spi.
> 
> This device can be found in the warp7 board [1], where it was tested.
> 
> ---
> Cheers,
>    Rui
> 
> v4->v5:
> Jonathan Cameron:
>   - remove init ret
>   - change handle of iio register, buffer and trigger in probe and
>    remove (I think this is what you mean, Jonathan)
You kind of ended up with both versions when it was an either or.
I'll have a go at tidying it up whilst applying. Please check the
result.

> 
> v3->v4:
> Tomasz Duszynski:
>   - mention irq flags in bindings
>   - add reference to drive-open-drain in bindings
>   - fix headers files
>   - drop comas in of_device_id sentinel
>   - drop of_match_ptr
>   - use probe_new
> 
> Jonathan Cameron:
>   - disable vdd regulator in case of vddio fail
>   - use devm_add_action_or_reset
>   - simpler functions returns
>   - remove noisy dev_info
>   - remove EAGAIN from runtime_suspend
> 
> v2->v3:
> Jonathan Cameron:
>   - cacheline aligned (DMA safe buffer)
>      Great presentation [2] and links in the presentation, thanks
>   - global renaming, including filenames, fxas2100x->fxas21002c
>   - provide spi info in dts bidings
>   - Remove SPI_MASTER in Kconfig i2c patch and move it to right patch
>   - remove extra blank line in comment
>   - add break range_value_from_fs after found
>   - in range_value_from_fs use local variable
>   - remove mode check at mode_set
>   - combine two if statements in mode_set
>   - in scale_get return 0 and let caller to set IIO_VAL_FRACTIONAL
>   - remove dev_err from vdd_io regulator get
>   - handle regulator error path
>   - devm_add_action
>   - check unwind order
>   - simplify data in _suspend and alike
>   - disable regulators at suspend
>   - error handling at _resume
>   - return -EAGAIN at runtime_resume
> 
> Rob Herring:
>    - Set label as gyroscope
> 
> - add interrupt to bindings
> - add entry to maintainers
> 
> 
> v1->v2:
> Peter Meerwal-Stadler:
>   - changed (c) to current year
>   - add regmap include file in .h
>   - fix comments s/cuttof/cutoff/
>   - add more info in mutex comment
>   - check value in range_fs_from_value
>   - ret not checked in range_value_from_fs
>   - move mode to enum type
>   - remove line between value get and validation of value in all file
>   - pre-write, regmap_field_write, post_write refactoring
>   - check val2 and val == 0 in write raw
>   - check in_anglvel_scale: 7.8125?
>   - trigger_handler: 2 => sizeof(s16)
>   - check buffer size
>   - print %02% to output chip id
>   - remove !! as state is bool
>   - trigger probe return devm_iio_trigger_register
>   - remove error msg in case of devm_iio_device_register
> Fabio Estebam:
>   - rename FXAS2100X to FXAS21002
>   - change compatible nxp,fxas2100x to the exact support
>   - add VDD and VDDIO regulators in bindings and driver
> 
> [0]: https://www.nxp.com/docs/en/data-sheet/FXAS21002.pdf
> [1]: https://www.element14.com/community/community/designcenter/single-board-computers/warp7/overview
> [2]: https://events.linuxfoundation.org/wp-content/uploads/2017/12/20181023-Wolfram-Sang-ELCE18-safe_dma_buffers.pdf
> 
> Rui Miguel Silva (6):
>   iio: gyro: add DT bindings to fxas21002c
>   iio: gyro: add core driver for fxas21002c
>   iio: gyro: fxas21002c: add i2c driver
>   iio: gyro: fxas21002c: add spi driver
>   ARM: dts: imx7s-warp: add fxas21002c gyroscope
>   MAINTAINERS: add entry for fxas21002c gyro driver
> 
>  .../bindings/iio/gyroscope/nxp,fxas21002c.txt |   31 +
>  MAINTAINERS                                   |   10 +
>  arch/arm/boot/dts/imx7s-warp.dts              |    7 +
>  drivers/iio/gyro/Kconfig                      |   22 +
>  drivers/iio/gyro/Makefile                     |    3 +
>  drivers/iio/gyro/fxas21002c.h                 |  151 +++
>  drivers/iio/gyro/fxas21002c_core.c            | 1006 +++++++++++++++++
>  drivers/iio/gyro/fxas21002c_i2c.c             |   69 ++
>  drivers/iio/gyro/fxas21002c_spi.c             |   70 ++
>  9 files changed, 1369 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
>  create mode 100644 drivers/iio/gyro/fxas21002c.h
>  create mode 100644 drivers/iio/gyro/fxas21002c_core.c
>  create mode 100644 drivers/iio/gyro/fxas21002c_i2c.c
>  create mode 100644 drivers/iio/gyro/fxas21002c_spi.c
>