RE: [PATCH 3/3] iio: imu: st_lsm6dsx: Add i3c basic support

From: Vitor Soares
Date: Tue Apr 16 2019 - 11:00:46 EST

Hi Boris and Lorenzo,

From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Date: Tue, Apr 16, 2019 at 09:05:40

> On Tue, 16 Apr 2019 09:58:33 +0200
> Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx> wrote:
>
> > >
> > > On Mon, 15 Apr 2019 21:19:41 +0200
> > > Vitor Soares <vitor.soares@xxxxxxxxxxxx> wrote:
> > >
> > > > For today the st_lsm6dsx driver support lsm6dso sensor only in
> > > > spi and i2c mode.
> > > >
> > > > The lsm6dso is also i3c capable so lets give i3c support to it.
> > > >
> > > > Signed-off-by: Vitor Soares <vitor.soares@xxxxxxxxxxxx>
> > > > ---
> > > > drivers/iio/imu/st_lsm6dsx/Kconfig | 8 +++-
> > > > drivers/iio/imu/st_lsm6dsx/Makefile | 1 +
> > > > drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c | 67 +++++++++++++++++++++++++++++
> > > > 3 files changed, 75 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 094fd00..1ab9bbf 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..2df5e70
> > > > --- /dev/null
> > > > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c
> > > > @@ -0,0 +1,67 @@
> > > > +// SPDX-License-Identifier: GPL-2.0
> > > > +/*
> > > > + * Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
> > > > + *
> > > > + * Author: Vitor Soares <vitor.soares@xxxxxxxxxxxx>
> > > > + */
> > > > +
> > > > +#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"
> > > > +
> > > > +#define NAME_SIZE 32
> > > > +
> > > > +struct st_lsm6dsx_i3c_data {
> > > > + char name[NAME_SIZE];
> > >
> > > const char *name;

I will fix this next patch.

> > >
> > > > + enum st_lsm6dsx_hw_id id;
> > > > +};
> > > > +
> > > > +static const struct st_lsm6dsx_i3c_data hw_data[] = {
> > >
> > > No need to make it an array, and it should probably be named
> > > st_lsm6dso_data not hw_data.
> >
> > I guess it will be used even for future devices so I would prefer to
> > make it an array with a 'general' name

The idea is that one. Are you ok with hw_data name?
Should I add the lsm6dsr support here or send in a different patch?

>
> I find it more error-prone to reference an array with an opaque index
> number than reference an instance with a name that clearly reflects
> what HW it describes (see the I3C_DEVICE() entry at the end of the
> driver), but okay.

I will address this next version.

>
> >
> > Regards,
> > Lorenzo
> >
> > >
> > > > + { ST_LSM6DSO_DEV_NAME, ST_LSM6DSO_ID },
> > > > +};
> > > > +
> > > > +static const struct regmap_config st_lsm6dsx_i3c_regmap_config = {
> > > > + .reg_bits = 8,
> > > > + .val_bits = 8,
> > > > +};
> > > > +
> > > > +static int st_lsm6dsx_i3c_probe(struct i3c_device *i3cdev)
> > > > +{
> > > > + const struct i3c_device_id *id = i3c_get_device_id(i3cdev);
> > >
> > > i3c_device_match_id(i3cdev,
> > > st_lsm6dsx_i3c_ids);
> > >
> > > > + const struct st_lsm6dsx_i3c_data *hw_data = id->data;
> > > > + 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, hw_data->id,
> > > > + hw_data->name, regmap);
> > > > +}
> > > > +
> > > > +
> > > > +static const struct i3c_device_id st_lsm6dsx_i3c_ids[] = {
> > > > + I3C_DEVICE(0x0104, 0x006C, &hw_data[0]),
> > > > + { /* sentinel */ },
> > > > +};
> > > > +MODULE_DEVICE_TABLE(i3c, st_lsm6dsx_i3c_ids);
> > > > +
> > > > +static struct i3c_driver st_lsm6dsx_driver = {
> > > > + .driver.name = "st_lsm6dsx_i3c",
> > > > + .probe = st_lsm6dsx_i3c_probe,
> > > > + .id_table = st_lsm6dsx_i3c_ids,
> > >
> > > You should probably set the pm_ops here (st_lsm6dsx_pm_ops).
> > >
> > > > +};
> > > > +module_i3c_driver(st_lsm6dsx_driver);
> > > > +
> > > > +MODULE_AUTHOR("Vitor Soares <vitor.soares@xxxxxxxxxxxx>");
> > > > +MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx i3c driver");
> > > > +MODULE_LICENSE("GPL v2");
> > > > +
> > >
> > > You can remove this blank line.
> > >
> >
> >

Best regards,
Vitor Soares