@@ -675,8 +675,9 @@ static int mtk_iommu_probe(struct platform_device *pdev)
return larb_nr;
for (i = 0; i < larb_nr; i++) {
- struct device_node *larbnode;
+ struct device_node *larbnode, *smicomm_node;
struct platform_device *plarbdev;
+ struct device_link *link;
u32 id;
larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
@@ -701,6 +702,28 @@ static int mtk_iommu_probe(struct platform_device *pdev)
component_match_add_release(dev, &match, release_of,
compare_of, larbnode);
+
+ /*
+ * Add link for smi-common and m4u once is ok. and the link is
+ * only needed while m4u has power-domain.
+ */
+ if (i || !pm_runtime_enabled(dev))
+ continue;
+
+ smicomm_node = of_parse_phandle(larbnode, "mediatek,smi", 0);
+ if (!smicomm_node) {
+ of_node_put(larbnode);
+ return -EINVAL;
+ }
+
+ plarbdev = of_find_device_by_node(smicomm_node);
+ of_node_put(smicomm_node);
+ data->smicomm_dev = &plarbdev->dev;
+
+ link = device_link_add(&plarbdev->dev, dev,
+ DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME);
+ if (!link)
+ dev_err(dev, "Unable link %s.\n", plarbdev->name);
}
platform_set_drvdata(pdev, data);
@@ -740,6 +763,7 @@ static int mtk_iommu_remove(struct platform_device *pdev)
if (iommu_present(&platform_bus_type))
bus_set_iommu(&platform_bus_type, NULL);
+ device_link_remove(data->smicomm_dev, &pdev->dev);
clk_disable_unprepare(data->bclk);
devm_free_irq(&pdev->dev, data->irq, data);
component_master_del(&pdev->dev, &mtk_iommu_com_ops);
@@ -66,6 +66,7 @@ struct mtk_iommu_data {
struct iommu_device iommu;
const struct mtk_iommu_plat_data *plat_data;
+ struct device *smicomm_dev;
struct list_head list;
struct mtk_smi_larb_iommu larb_imu[MTK_LARB_NR_MAX];
In the lastest SoC, M4U has its special power domain. thus, If the engine begin to work, it should help enable the power for M4U firstly. Currently if the engine work, it always enable the power/clocks for smi-larbs/smi-common. This patch adds device_link for smi-common and M4U. then, if smi-common power is enabled, the M4U power also is powered on automatically. In this patch, a M4U connects with several smi-larbs and their smi-common always are the same, thus it adds the device-link once is enough. And the devicelink only is needed while m4u has power-domain. Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- drivers/iommu/mtk_iommu.c | 26 +++++++++++++++++++++++++- drivers/iommu/mtk_iommu.h | 1 + 2 files changed, 26 insertions(+), 1 deletion(-)