On Thu, Jul 15, 2021 at 8:25 PM Yong Wu <yong.wu@xxxxxxxxxxxx> wrote:
>
> In mt8195, there are some larbs connect with the smi-sub-common, then
> connect with smi-common.
Not critical but I suggest to describe what is smi-sub-common.
e.g. "some larbs are not directly connected to smi-common,
they are connected to smi-sub-common which is a bridge(?) interface to..."
>
> 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.
>
> There is no SW extra setting for smi-sub-common.
>
> 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 e68cbb51dd12..ee49bb50f5f5 100644
> --- a/drivers/memory/mtk-smi.c
> +++ b/drivers/memory/mtk-smi.c
> @@ -60,7 +60,8 @@
>
> 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
> @@ -90,13 +91,14 @@ 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;
> @@ -259,6 +261,38 @@ 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,
> unsigned int clk_nr_optional,
> const char * const clk_optional[])
> @@ -285,9 +319,6 @@ 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);
> @@ -307,26 +338,10 @@ 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);
> @@ -471,6 +486,14 @@ 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;
> @@ -478,6 +501,10 @@ 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
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