Re: [PATCH v4 3/3] mfd: cros_ec: Don't add cros_ec_ucsi if it is defined in OF or ACPI

Abhishek Pandit-Subedi
2025-11-06T18:18:36Z

On Mon, Oct 13, 2025 at 1:34 PM Jameson Thies <jthies@google.com> wrote:
>
> On devices with a UCSI PPM in the EC, check for cros_ec_ucsi to be
> defined in the OF device tree or an ACPI node. If it is defined by
> either OF or ACPI, it does not need to be added as a subdevice of
> cros_ec_dev mfd. cros_ec_ucsi will load from the OF or ACPI node.
>
> Signed-off-by: Jameson Thies <jthies@google.com>
> Reviewed-by: Benson Leung <bleung@chromium.org>
> ---
> drivers/mfd/cros_ec_dev.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index dc80a272726b..1928c2ea2b8f 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -5,6 +5,7 @@
> * Copyright (C) 2014 Google, Inc.
> */
>
> +#include <linux/acpi.h>
> #include <linux/dmi.h>
> #include <linux/kconfig.h>
> #include <linux/mfd/core.h>
> @@ -131,11 +132,6 @@ static const struct cros_feature_to_cells cros_subdevices[] = {
> .mfd_cells = cros_ec_rtc_cells,
> .num_cells = ARRAY_SIZE(cros_ec_rtc_cells),
> },
> - {
> - .id = EC_FEATURE_UCSI_PPM,
> - .mfd_cells = cros_ec_ucsi_cells,
> - .num_cells = ARRAY_SIZE(cros_ec_ucsi_cells),
> - },
> {
> .id = EC_FEATURE_HANG_DETECT,
> .mfd_cells = cros_ec_wdt_cells,
> @@ -264,6 +260,23 @@ static int ec_device_probe(struct platform_device *pdev)
> }
> }
>
> + /*
> + * FW nodes can load cros_ec_ucsi, but early PDC devices did not define
> + * the required nodes. On PDC systems without FW nodes for cros_ec_ucsi,
> + * the driver should be added as an mfd subdevice.
> + */
> + if (cros_ec_check_features(ec, EC_FEATURE_USB_PD) &&
> + cros_ec_check_features(ec, EC_FEATURE_UCSI_PPM) &&
> + !acpi_dev_found("GOOG0021") &&
> + !of_find_compatible_node(NULL, NULL, "google,cros-ec-ucsi")) {
> + retval = mfd_add_hotplug_devices(ec->dev,
> + cros_ec_ucsi_cells,
> + ARRAY_SIZE(cros_ec_ucsi_cells));
> +
> + if (retval)
> + dev_warn(ec->dev, "failed to add cros_ec_ucsi: %d\n", retval);
> + }
> +
> /*
> * UCSI provides power supply information so we don't need to separately
> * load the cros_usbpd_charger driver.
> --
> 2.51.0.858.gf9c4a03a3a-goog
>

Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>