[PATCH v3 07/13] memory: mtk-smi: Add device link for smi-sub-common

From: Yong Wu
Date: Tue Aug 10 2021 - 04:12:05 EST


In mt8195, there are some larbs connect with the smi-sub-common, then
connect with smi-common.

Before we create device link between smi-larb with smi-common. If we have
sub-common, we should use device link the smi-larb and smi-sub-common,
then use device link between the smi-sub-common with smi-common. This is
for enabling clock/power automatically.

Move the device link code to a new interface for reusing.

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
Reviewed-by: Ikjoon Jang <ikjn@xxxxxxxxxxxx>
---
drivers/memory/mtk-smi.c | 75 +++++++++++++++++++++++++++-------------
1 file changed, 51 insertions(+), 24 deletions(-)

diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index b362d528944e..5c2bd5795cfd 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -61,7 +61,8 @@

enum mtk_smi_type {
MTK_SMI_GEN1,
- MTK_SMI_GEN2
+ MTK_SMI_GEN2, /* gen2 smi common */
+ MTK_SMI_GEN2_SUB_COMM, /* gen2 smi sub common */
};

#define MTK_SMI_CLK_NR_MAX 4
@@ -99,13 +100,14 @@ struct mtk_smi {
void __iomem *smi_ao_base; /* only for gen1 */
void __iomem *base; /* only for gen2 */
};
+ struct device *smi_common_dev; /* for sub common */
const struct mtk_smi_common_plat *plat;
};

struct mtk_smi_larb { /* larb: local arbiter */
struct mtk_smi smi;
void __iomem *base;
- struct device *smi_common_dev;
+ struct device *smi_common_dev; /* common or sub-common dev */
const struct mtk_smi_larb_gen *larb_gen;
int larbid;
u32 *mmu;
@@ -268,6 +270,38 @@ static const struct of_device_id mtk_smi_larb_of_ids[] = {
{}
};

+static int mtk_smi_device_link_common(struct device *dev, struct device **com_dev)
+{
+ struct platform_device *smi_com_pdev;
+ struct device_node *smi_com_node;
+ struct device *smi_com_dev;
+ struct device_link *link;
+
+ smi_com_node = of_parse_phandle(dev->of_node, "mediatek,smi", 0);
+ if (!smi_com_node)
+ return -EINVAL;
+
+ smi_com_pdev = of_find_device_by_node(smi_com_node);
+ of_node_put(smi_com_node);
+ if (smi_com_pdev) {
+ /* smi common is the supplier, Make sure it is ready before */
+ if (!platform_get_drvdata(smi_com_pdev))
+ return -EPROBE_DEFER;
+ smi_com_dev = &smi_com_pdev->dev;
+ link = device_link_add(dev, smi_com_dev,
+ DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+ if (!link) {
+ dev_err(dev, "Unable to link smi-common dev\n");
+ return -ENODEV;
+ }
+ *com_dev = smi_com_dev;
+ } else {
+ dev_err(dev, "Failed to get the smi_common device\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
static int mtk_smi_dts_clk_init(struct device *dev, struct mtk_smi *smi,
const char * const clks[],
unsigned int clk_nr_required,
@@ -294,9 +328,6 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
struct mtk_smi_larb *larb;
struct resource *res;
struct device *dev = &pdev->dev;
- struct device_node *smi_node;
- struct platform_device *smi_pdev;
- struct device_link *link;
int ret;

larb = devm_kzalloc(dev, sizeof(*larb), GFP_KERNEL);
@@ -315,26 +346,10 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
return ret;

larb->smi.dev = dev;
- smi_node = of_parse_phandle(dev->of_node, "mediatek,smi", 0);
- if (!smi_node)
- return -EINVAL;

- smi_pdev = of_find_device_by_node(smi_node);
- of_node_put(smi_node);
- if (smi_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;
- }
+ ret = mtk_smi_device_link_common(dev, &larb->smi_common_dev);
+ if (ret < 0)
+ return ret;

pm_runtime_enable(dev);
platform_set_drvdata(pdev, larb);
@@ -483,6 +498,14 @@ static int mtk_smi_common_probe(struct platform_device *pdev)
if (IS_ERR(common->base))
return PTR_ERR(common->base);
}
+
+ /* link its smi-common if this is smi-sub-common */
+ if (common->plat->type == MTK_SMI_GEN2_SUB_COMM) {
+ ret = mtk_smi_device_link_common(dev, &common->smi_common_dev);
+ if (ret < 0)
+ return ret;
+ }
+
pm_runtime_enable(dev);
platform_set_drvdata(pdev, common);
return 0;
@@ -490,6 +513,10 @@ static int mtk_smi_common_probe(struct platform_device *pdev)

static int mtk_smi_common_remove(struct platform_device *pdev)
{
+ struct mtk_smi *common = dev_get_drvdata(&pdev->dev);
+
+ if (common->plat->type == MTK_SMI_GEN2_SUB_COMM)
+ device_link_remove(&pdev->dev, common->smi_common_dev);
pm_runtime_disable(&pdev->dev);
return 0;
}
--
2.18.0