RE: [PATCH v4 3/3] iio: imu: st_lsm6dsx: add i3c basic support for LSM6DSO and LSM6DSR

Vitor Soares
2019-07-12T16:28:16Z

From: Boris Brezillon <boris.brezillon@collabora.com>
Date: Fri, Jul 12, 2019 at 17:14:29

> On Fri, 12 Jul 2019 13:53:30 +0200
> Vitor Soares <Vitor.Soares@synopsys.com> wrote:
>
> > For today the st_lsm6dsx driver support LSM6DSO and LSM6DSR sensor only in
> > spi and i2c mode.
> >
> > The LSM6DSO and LSM6DSR are also i3c capable so lets give i3c support to
> > them.
> >
> > Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
> > Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> > Changes in v4:
> > Remove hw_id variable
> >
> > Changes in v3:
> > Remove unnecessary st_lsm6dsx_i3c_data table used to hold device name
> > Use st_lsm6dsx_probe new form
> >
> > Changes in v2:
> > Add support for LSM6DSR
> > Set pm_ops to st_lsm6dsx_pm_ops
> >
> > drivers/iio/imu/st_lsm6dsx/Kconfig | 8 +++-
> > drivers/iio/imu/st_lsm6dsx/Makefile | 1 +
> > drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c | 58 +++++++++++++++++++++++++++++
> > 3 files changed, 66 insertions(+), 1 deletion(-)
> > create mode 100644 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c
> >
> > diff --git a/drivers/iio/imu/st_lsm6dsx/Kconfig b/drivers/iio/imu/st_lsm6dsx/Kconfig
> > index 9e59297..6b5a73c 100644
> > --- a/drivers/iio/imu/st_lsm6dsx/Kconfig
> > +++ b/drivers/iio/imu/st_lsm6dsx/Kconfig
> > @@ -1,11 +1,12 @@
> >
> > config IIO_ST_LSM6DSX
> > tristate "ST_LSM6DSx driver for STM 6-axis IMU MEMS sensors"
> > - depends on (I2C || SPI)
> > + depends on (I2C || SPI || I3C)
> > select IIO_BUFFER
> > select IIO_KFIFO_BUF
> > select IIO_ST_LSM6DSX_I2C if (I2C)
> > select IIO_ST_LSM6DSX_SPI if (SPI_MASTER)
> > + select IIO_ST_LSM6DSX_I3C if (I3C)
> > help
> > Say yes here to build support for STMicroelectronics LSM6DSx imu
> > sensor. Supported devices: lsm6ds3, lsm6ds3h, lsm6dsl, lsm6dsm,
> > @@ -23,3 +24,8 @@ config IIO_ST_LSM6DSX_SPI
> > tristate
> > depends on IIO_ST_LSM6DSX
> > select REGMAP_SPI
> > +
> > +config IIO_ST_LSM6DSX_I3C
> > + tristate
> > + depends on IIO_ST_LSM6DSX
> > + select REGMAP_I3C
> > diff --git a/drivers/iio/imu/st_lsm6dsx/Makefile b/drivers/iio/imu/st_lsm6dsx/Makefile
> > index e5f733c..c676965 100644
> > --- a/drivers/iio/imu/st_lsm6dsx/Makefile
> > +++ b/drivers/iio/imu/st_lsm6dsx/Makefile
> > @@ -4,3 +4,4 @@ st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o \
> > obj-$(CONFIG_IIO_ST_LSM6DSX) += st_lsm6dsx.o
> > obj-$(CONFIG_IIO_ST_LSM6DSX_I2C) += st_lsm6dsx_i2c.o
> > obj-$(CONFIG_IIO_ST_LSM6DSX_SPI) += st_lsm6dsx_spi.o
> > +obj-$(CONFIG_IIO_ST_LSM6DSX_I3C) += st_lsm6dsx_i3c.o
> > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c
> > new file mode 100644
> > index 0000000..2e89524
> > --- /dev/null
> > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c
> > @@ -0,0 +1,58 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
> > + *
> > + * Author: Vitor Soares <vitor.soares@synopsys.com>
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/i3c/device.h>
> > +#include <linux/i3c/master.h>
> > +#include <linux/slab.h>
> > +#include <linux/of.h>
> > +#include <linux/regmap.h>
> > +
> > +#include "st_lsm6dsx.h"
> > +
> > +static const struct i3c_device_id st_lsm6dsx_i3c_ids[] = {
> > + I3C_DEVICE(0x0104, 0x006C, (void *)ST_LSM6DSO_ID),
> > + I3C_DEVICE(0x0104, 0x006B, (void *)ST_LSM6DSR_ID),
>
> I think you need an uintptr_t cast here:
>
> I3C_DEVICE(0x0104, 0x006C, (void *)(uintptr_t)ST_LSM6DSO_ID),
> I3C_DEVICE(0x0104, 0x006B, (void *)(uintptr_t)ST_LSM6DSR_ID),
>
> otherwise gcc might complain that the integer and pointer do not have
> the same size (on 64-bit architectures).

I don't understand this part. Can you provide or point some background?

>
> > + { /* sentinel */ },
> > +};
> > +MODULE_DEVICE_TABLE(i3c, st_lsm6dsx_i3c_ids);
> > +
> > +static const struct regmap_config st_lsm6dsx_i3c_regmap_config = {
> > + .reg_bits = 8,
> > + .val_bits = 8,
> > +};
>
> This can be moved ...
>
> > +
> > +static int st_lsm6dsx_i3c_probe(struct i3c_device *i3cdev)
> > +{
>
> ... here without the static and const qualifiers:

I understand that can be move to here, but I don't understand the
advantages. Can you explain?

>
> struct regmap_config regmap_config = {
> .reg_bits = 8,
> .val_bits = 8,
> };
>
> > + const struct i3c_device_id *id = i3c_device_match_id(i3cdev,
> > + st_lsm6dsx_i3c_ids);
> > + struct regmap *regmap;
> > +
> > + regmap = devm_regmap_init_i3c(i3cdev, &st_lsm6dsx_i3c_regmap_config);
> > + if (IS_ERR(regmap)) {
> > + dev_err(&i3cdev->dev, "Failed to register i3c regmap %d\n",
> > + (int)PTR_ERR(regmap));
> > + return PTR_ERR(regmap);
> > + }
> > +
> > + return st_lsm6dsx_probe(&i3cdev->dev, 0, (int)id->data, regmap);
>
> uintptr_t cast here.
>
> > +}
> > +
> > +static struct i3c_driver st_lsm6dsx_driver = {
> > + .driver = {
> > + .name = "st_lsm6dsx_i3c",
> > + .pm = &st_lsm6dsx_pm_ops,
> > + },
> > + .probe = st_lsm6dsx_i3c_probe,
> > + .id_table = st_lsm6dsx_i3c_ids,
> > +};
> > +module_i3c_driver(st_lsm6dsx_driver);
> > +
> > +MODULE_AUTHOR("Vitor Soares <vitor.soares@synopsys.com>");
> > +MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx i3c driver");
> > +MODULE_LICENSE("GPL v2");

Best regards,
Vitor Soares