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

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

HI Lorenzo,

From: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Date: Mon, Apr 15, 2019 at 23:17:50

> >
> > 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.
> >
> 
> Hi Vitor,
> 
> thx, this is very cool :)
> Just a couple of nit inline
> 
> Regards,
> Lorenzo
> 
> > Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
> > ---
> >  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@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"
> > +
> > +#define NAME_SIZE      32
> > +
> > +struct st_lsm6dsx_i3c_data {
> > +       char name[NAME_SIZE];
> > +       enum st_lsm6dsx_hw_id id;
> > +};
> > +
> > +static const struct st_lsm6dsx_i3c_data hw_data[] = {
> > +       { 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);
> > +       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);
> 
> In order to support the hw FIFO, I guess you are planning to support
> interrupts/IBI here

My idea is to register the ibi and handler in this file.
The handler would call a buffer function passing the device and payload. 
On st_lsm6dsx_probe we can add a flag for IBI configuration on the sensor 
side.

> 
> > +}
> > +
> 
> please remove 'new line' here

Sure.

> 
> > +
> > +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,
> > +};
> > +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
> >
> 
> 
> -- 
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> unzip; touch; strip; gasp; finger; gasp; mount; fsck; more; yes; gasp;
> umount; make clean; sleep

Thanks for your feedback.

Best regards,
Vitor Soares