RE: [PATCH v3 3/3] iio: imu: st_lsm6dsx: add i3c basic support for LSM6DSO and LSM6DSR

[Vitor Soares <Vitor.Soares@synopsys.com>]

Hi Lorenzo,

From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Wed, Jul 10, 2019 at 20:44:05

> > 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.
> 
> Hi Vitor,
> 
> just few comments inline.
> 
> Regards,
> Lorenzo
> 
> > 
> > Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
> > Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> > 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 | 61 +++++++++++++++++++++++++++++
> >  3 files changed, 69 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c
> > 
> 
> [...]
> 
> > 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..f683754
> > --- /dev/null
> > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c
> > @@ -0,0 +1,61 @@
> > +// 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[];
> > +
> 
> why do we need this? I guess you can just move st_lsm6dsx_i3c_ids definition here
> 
> > +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_device_match_id(i3cdev,
> > +							    st_lsm6dsx_i3c_ids);
> 
> i3c_device_match_id can theoretically fail so is it better to check
> return value here? (maybe I am too paranoid :))
> 
> > +	struct regmap *regmap;
> > +	int hw_id = (int)id->data;
> 
> I guess we do not need this since we use it just in st_lsm6dsx_probe(),
> we can just do:
> 
> return st_lsm6dsx_probe(&i3cdev->dev, 0, (int)id->data, 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_id, regmap);
> > +}
> > +
> > +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),
> > +	{ /* sentinel */ },
> > +};
> > +MODULE_DEVICE_TABLE(i3c, st_lsm6dsx_i3c_ids);
> > +
> > +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");
> > -- 
> > 2.7.4
> > 

Thanks for your comments. I will address them and send a new version.

Best regards,
Vitor Soares