[PATCH v3 04/14] memory: mtk-smi: Add device-link between smi-larb and smi-common

Yong Wu
2019-09-03T09:38:54Z

Normally, If the smi-larb HW need work, we should enable the smi-common
HW power and clock firstly.
This patch adds device-link between the smi-larb dev and the smi-common
dev. then If pm_runtime_get_sync(smi-larb-dev), the pm_runtime_get_sync
(smi-common-dev) will be called automatically.

Also, Add DL_FLAG_STATELESS to avoid the smi-common clocks be gated when
probe.

CC: Matthias Brugger <matthias.bgg@gmail.com>
Suggested-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
drivers/memory/mtk-smi.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index 439d7d8..5dab56c 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -273,6 +273,7 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct device_node *smi_node;
struct platform_device *smi_pdev;
+ struct device_link *link;

larb = devm_kzalloc(dev, sizeof(*larb), GFP_KERNEL);
if (!larb)
@@ -312,6 +313,12 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
if (!platform_get_drvdata(smi_pdev))
return -EPROBE_DEFER;
larb->smi_common_dev = &smi_pdev->dev;
+ link = device_link_add(dev, larb->smi_common_dev,
+ DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+ if (!link) {
+ dev_err(dev, "Unable to link smi-common dev\n");
+ return -ENODEV;
+ }
} else {
dev_err(dev, "Failed to get the smi_common device\n");
return -EINVAL;
@@ -324,6 +331,9 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)

static int mtk_smi_larb_remove(struct platform_device *pdev)
{
+ struct mtk_smi_larb *larb = platform_get_drvdata(pdev);
+
+ device_link_remove(&pdev->dev, larb->smi_common_dev);
pm_runtime_disable(&pdev->dev);
component_del(&pdev->dev, &mtk_smi_larb_component_ops);
return 0;
@@ -335,17 +345,9 @@ static int __maybe_unused mtk_smi_larb_resume(struct device *dev)
const struct mtk_smi_larb_gen *larb_gen = larb->larb_gen;
int ret;

- /* Power on smi-common. */
- ret = pm_runtime_get_sync(larb->smi_common_dev);
- if (ret < 0) {
- dev_err(dev, "Failed to pm get for smi-common(%d).\n", ret);
- return ret;
- }
-
ret = mtk_smi_clk_enable(&larb->smi);
if (ret < 0) {
dev_err(dev, "Failed to enable clock(%d).\n", ret);
- pm_runtime_put_sync(larb->smi_common_dev);
return ret;
}

@@ -360,7 +362,6 @@ static int __maybe_unused mtk_smi_larb_suspend(struct device *dev)
struct mtk_smi_larb *larb = dev_get_drvdata(dev);

mtk_smi_clk_disable(&larb->smi);
- pm_runtime_put_sync(larb->smi_common_dev);
return 0;