On Wed, Oct 04, 2017 at 10:51:29AM +0200, Frédéric Danis wrote:
> This patch allows SerDev module to manage serial devices declared as
> attached to an UART in ACPI table.
>
> acpi_serdev_add_device() callback will only take into account entries
> without enumerated flag set. This flags is set for all entries during
> ACPI scan, except for SPI and I2C serial devices, and for UART with
> 2nd patch in the series.
>
> Signed-off-by: Frédéric Danis <frederic.danis.oss@xxxxxxxxx>
> ---
> drivers/tty/serdev/core.c | 99 ++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 94 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
> index c68fb3a..104777d 100644
> --- a/drivers/tty/serdev/core.c
> +++ b/drivers/tty/serdev/core.c
> @@ -385,6 +401,74 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
> return 0;
> }
>
> +#ifdef CONFIG_ACPI
> +static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
> + struct acpi_device *adev)
> +{
> + struct serdev_device *serdev = NULL;
> + int err;
> +
> + if (acpi_bus_get_status(adev) || !adev->status.present ||
> + acpi_device_enumerated(adev))
> + return AE_OK;
> +
> + serdev = serdev_device_alloc(ctrl);
> + if (!serdev) {
> + dev_err(&ctrl->dev, "failed to allocate Serial device for %s\n",
s/Serial/serdev/
> + dev_name(&adev->dev));
> + return AE_NO_MEMORY;
> + }
> +
> + ACPI_COMPANION_SET(&serdev->dev, adev);
> + acpi_device_set_enumerated(adev);
> +
> + err = serdev_device_add(serdev);
> + if (err) {
> + dev_err(&serdev->dev,
> + "failure adding ACPI device. status %d\n", err);
s/ACPI/ACPI serdev/?
> + serdev_device_put(serdev);
> + }
> +
> + return AE_OK;
> +}
> +
> +static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
> + void *data, void **return_value)
> +{
> + struct serdev_controller *ctrl = data;
> + struct acpi_device *adev;
> +
> + if (acpi_bus_get_device(handle, &adev))
> + return AE_OK;
> +
> + return acpi_serdev_register_device(ctrl, adev);
> +}
> +
> +static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
> +{
> + acpi_status status;
> + acpi_handle handle;
> +
> + handle = ACPI_HANDLE(ctrl->dev.parent);
> + if (!handle)
> + return -ENODEV;
> +
> + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
> + acpi_serdev_add_device, NULL, ctrl, NULL);
> + if (ACPI_FAILURE(status)) {
> + dev_warn(&ctrl->dev, "failed to enumerate Serial slaves\n");
s/Serial/serdev/
> + return -ENODEV;
> + }
> +
> + return 0;
What if there are no slaves defined? I'm not very familiar with the ACPI
helpers, but from a quick look it seems you'd then end up returning zero
here which would cause the serdev controller to be registered instead of
the tty-class device.
[ And if I'm mistaken, you do want to suppress that error message for
when there are no slaves defined. ]
> +}
> +#else
> +static inline int acpi_serdev_register_devices(struct serdev_controller *ctlr)
s/ctlr/ctrl/
> +{
> + return -ENODEV;
> +}
> +#endif /* CONFIG_ACPI */
> +
> /**
> * serdev_controller_add() - Add an serdev controller
> * @ctrl: controller to be registered.
> @@ -394,7 +478,7 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
> */
> int serdev_controller_add(struct serdev_controller *ctrl)
> {
> - int ret;
> + int ret_of, ret_acpi, ret;
>
> /* Can't register until after driver model init */
> if (WARN_ON(!is_registered))
> @@ -404,9 +488,14 @@ int serdev_controller_add(struct serdev_controller *ctrl)
> if (ret)
> return ret;
>
> - ret = of_serdev_register_devices(ctrl);
> - if (ret)
> + ret_of = of_serdev_register_devices(ctrl);
> + ret_acpi = acpi_serdev_register_devices(ctrl);
> + if (ret_of && ret_acpi) {
> + dev_dbg(&ctrl->dev, "serdev%d no devices registered: of:%d acpi:%d\n",
"serdev%d" is redundant here as you're using dev_dbg (which will print
the device name).
> + ctrl->nr, ret_of, ret_acpi);
> + ret = -ENODEV;
> goto out_dev_del;
> + }
>
> dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
> ctrl->nr, &ctrl->dev);
Hmm, I see it's already used here. No need to follow that example
though.
Johan
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