| Message ID | 20240930044525.2043884-4-wenst@chromium.org (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Add of_regulator_get_optional() and Fix MTK Power Domain Driver | expand |
Il 30/09/24 06:45, Chen-Yu Tsai ha scritto: > The MediaTek power domain driver contains a hack that assigns the device > node of the power domain to the struct device of the power domain > controller in order to use the devres regulator API. > > Now that there is a proper OF-specific regulator API, and even a devres > version, replace the hack with proper code. > > This change is incompatible with incomplete device trees. Instead of > assigning the dummy regulator in cases where the power domain requires > a supply but the device tree does not provide one, the driver will just > error out. This will be seen on the MT8390 EVK, which is missing > supplies for the IMG_VCORE and CAM_VCORE domains. And likely all the > MediaTek EVBs, which have no power domain supplies specified. This is > however the correct behavior. If the power domain's supply is missing, > then it should not work. Relying on other parts of the system to keep > the unattached regulator enabled is likely to break in ways less easier > to understand. > > Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
diff --git a/drivers/pmdomain/mediatek/mtk-pm-domains.c b/drivers/pmdomain/mediatek/mtk-pm-domains.c index 88406e9ac63c..3580913f25d3 100644 --- a/drivers/pmdomain/mediatek/mtk-pm-domains.c +++ b/drivers/pmdomain/mediatek/mtk-pm-domains.c @@ -353,7 +353,6 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no { const struct scpsys_domain_data *domain_data; struct scpsys_domain *pd; - struct device_node *root_node = scpsys->dev->of_node; struct device_node *smi_node; struct property *prop; const char *clk_name; @@ -388,16 +387,7 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no pd->scpsys = scpsys; if (MTK_SCPD_CAPS(pd, MTK_SCPD_DOMAIN_SUPPLY)) { - /* - * Find regulator in current power domain node. - * devm_regulator_get() finds regulator in a node and its child - * node, so set of_node to current power domain node then change - * back to original node after regulator is found for current - * power domain node. - */ - scpsys->dev->of_node = node; - pd->supply = devm_regulator_get(scpsys->dev, "domain"); - scpsys->dev->of_node = root_node; + pd->supply = devm_of_regulator_get_optional(scpsys->dev, node, "domain"); if (IS_ERR(pd->supply)) return dev_err_cast_probe(scpsys->dev, pd->supply, "%pOF: failed to get power supply.\n",
The MediaTek power domain driver contains a hack that assigns the device node of the power domain to the struct device of the power domain controller in order to use the devres regulator API. Now that there is a proper OF-specific regulator API, and even a devres version, replace the hack with proper code. This change is incompatible with incomplete device trees. Instead of assigning the dummy regulator in cases where the power domain requires a supply but the device tree does not provide one, the driver will just error out. This will be seen on the MT8390 EVK, which is missing supplies for the IMG_VCORE and CAM_VCORE domains. And likely all the MediaTek EVBs, which have no power domain supplies specified. This is however the correct behavior. If the power domain's supply is missing, then it should not work. Relying on other parts of the system to keep the unattached regulator enabled is likely to break in ways less easier to understand. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> --- Changes since v7: - New patch The other option is to follow what Rockchip will be doing: getting the regulator supply upon first use / enable [1]. This will result in less breakage: only the power domain that is missing its supplies will fail to be attached. [1] https://lore.kernel.org/all/20240919091834.83572-6-sebastian.reichel@collabora.com/ --- drivers/pmdomain/mediatek/mtk-pm-domains.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-)