[PATCH 2/2] power: supply: Add Lenovo Yoga C630 EC driver
Sebastian Reichel
sebastian.reichel at collabora.com
Tue Sep 13 10:45:45 UTC 2022
Hi,
[+Cc Lee Jones, DRI devel]
On Tue, Aug 09, 2022 at 10:05:00PM -0500, Bjorn Andersson wrote:
> The Qualcomm Snapdragon-based Lenovo Yoga C630 has some sort of EC
> providing AC-adapter and battery status, as well as USB Type-C altmode
> notifications for Displayport operation.
>
> The Yoga C630 ships with Windows, where these operations primarily are
> implemented in ACPI, but due to various issues with the hardware
> representation therein it's not possible to run Linux on this
> information. As such this is a best-effort re-implementation of these
> operations, based on the register map expressed in ACPI and a fair
> amount of trial and error.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson at linaro.org>
> ---
> [...]
> + val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_ATTRIBUTES);
> + if (val < 0)
> + goto out_unlock;
> + ec->unit_ma = val & LENOVO_EC_BAT_ATTR_UNIT_IS_MA;
> + if (!ec->unit_ma)
> + ec->scale = 1000;
> + else
> + ec->scale = 1;
Since I'm not sure how much of information was gained by reverse
engineering: Is this really milliamps vs microamps and not milliamps
vs milliwatt? SBS batteries usually report either mA or mW.
> [...]
> + case POWER_SUPPLY_PROP_SERIAL_NUMBER:
> + val->strval = "05072018";
> + break;
why is this hardcoded? :)
> [...]
> + device_for_each_child_node(dev, fwnode) {
> + ret = fwnode_property_read_u32(fwnode, "reg", &port);
> + if (ret < 0)
> + continue;
> +
> + /* Got multiple ports, but altmode is only possible on port 1 */
> + if (port != 1)
> + continue;
> +
> + ec->bridge.funcs = &yoga_c630_ec_bridge_funcs;
> + ec->bridge.of_node = to_of_node(fwnode);
> + ec->bridge.ops = DRM_BRIDGE_OP_HPD;
> + ec->bridge.type = DRM_MODE_CONNECTOR_USB;
> +
> + ret = devm_drm_bridge_add(dev, &ec->bridge);
> + if (ret) {
> + dev_err(dev, "failed to register drm bridge\n");
> + fwnode_handle_put(fwnode);
> + return ret;
> + }
I wonder if DRM people want to see this in drivers/gpu/drm/bridge.
Maybe it's better to make this a MFD driver?
> [...]
-- Sebastian
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