Re: [PATCH 4/8] iio: accel: bmc150: Add support for dual-accelerometers with a DUAL250E HID

From: Jonathan Cameron <jic23@kernel.org>
To: Hans de Goede <hdegoede@redhat.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Jeremy Cline <jeremy@jcline.org>,
	linux-iio@vger.kernel.org,
	Charles Keepax <ckeepax@opensource.cirrus.com>,
	patches@opensource.cirrus.com, alsa-devel@alsa-project.org
Subject: Re: [PATCH 4/8] iio: accel: bmc150: Add support for dual-accelerometers with a DUAL250E HID
Date: Sat, 22 May 2021 18:43:36 +0100	[thread overview]
Message-ID: <20210522184336.09c219cd@jic23-huawei> (raw)
In-Reply-To: <20210521171418.393871-5-hdegoede@redhat.com>

On Fri, 21 May 2021 19:14:14 +0200
Hans de Goede <hdegoede@redhat.com> wrote:

> The Lenovo Yoga 300-11IBR has a ACPI fwnode with a HID of DUAL250E
> which contains I2C and IRQ resources for 2 accelerometers, 1 in the
> display and one in the base of the device. Add support for this.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/iio/accel/bmc150-accel-i2c.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iio/accel/bmc150-accel-i2c.c b/drivers/iio/accel/bmc150-accel-i2c.c
> index e24ce28a4660..b81e4005788e 100644
> --- a/drivers/iio/accel/bmc150-accel-i2c.c
> +++ b/drivers/iio/accel/bmc150-accel-i2c.c
> @@ -24,6 +24,7 @@
>  #ifdef CONFIG_ACPI
>  static const struct acpi_device_id bmc150_acpi_dual_accel_ids[] = {
>  	{"BOSC0200"},
> +	{"DUAL250E"},
>  	{ },
>  };
>  
> @@ -35,21 +36,24 @@ static void bmc150_acpi_dual_accel_probe(struct i2c_client *client)
>  {
>  	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
>  	struct i2c_client *second_dev;
> +	char dev_name[16];

I'm a bit in two minds about having a fixed length array for this.
Obviously this is always big enough (I think a bit too big), but it
might be a place where a future bug is introduced.  Perhaps it's worth the dance
of a kasprintf and kfree, to avoid that possibility?

>  	struct i2c_board_info board_info = {
>  		.type = "bmc150_accel",
> -		/*
> -		 * The 2nd accel sits in the base of 2-in-1s. Note this
> -		 * name is static, as there should never be more then 1
> -		 * BOSC0200 ACPI node with 2 accelerometers in it.
> -		 */
> -		.dev_name = "BOSC0200:base",
> +		.dev_name = dev_name,
>  		.fwnode = client->dev.fwnode,
> -		.irq = -ENOENT,
>  	};
>  
>  	if (acpi_match_device_ids(adev, bmc150_acpi_dual_accel_ids))
>  		return;
>  
> +	/*
> +	 * The 2nd accel sits in the base of 2-in-1s. The suffix is static, as
> +	 * there should never be more then 1 ACPI node with 2 accelerometers in it.
> +	 */
> +	snprintf(dev_name, sizeof(dev_name), "%s:base", acpi_device_hid(adev));
> +
> +	board_info.irq = acpi_dev_gpio_irq_get_by(adev, NULL, 1);
> +
>  	second_dev = i2c_acpi_new_device(&client->dev, 1, &board_info);
>  	if (!IS_ERR(second_dev))
>  		bmc150_set_second_device(client, second_dev);
> @@ -114,6 +118,7 @@ static const struct acpi_device_id bmc150_accel_acpi_match[] = {
>  	{"BMA222E",	bma222e},
>  	{"BMA0280",	bma280},
>  	{"BOSC0200"},
> +	{"DUAL250E"},
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(acpi, bmc150_accel_acpi_match);