On Thu, 7 Apr 2022, at 17:27, Dylan Hung wrote:
> Add reset assertion/deassertion for Aspeed MDIO. There are 4 MDIO
> controllers embedded in Aspeed AST2600 SOC and share one reset control
> register SCU50[3]. To work with old DT blobs which don't have the reset
> property, devm_reset_control_get_optional_shared is used in this change.
>
> Signed-off-by: Dylan Hung <dylan_hung@xxxxxxxxxxxxxx>
> Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> ---
> drivers/net/mdio/mdio-aspeed.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c
> index e2273588c75b..1afb58ccc524 100644
> --- a/drivers/net/mdio/mdio-aspeed.c
> +++ b/drivers/net/mdio/mdio-aspeed.c
> @@ -3,6 +3,7 @@
>
> #include <linux/bitfield.h>
> #include <linux/delay.h>
> +#include <linux/reset.h>
> #include <linux/iopoll.h>
> #include <linux/mdio.h>
> #include <linux/module.h>
> @@ -37,6 +38,7 @@
>
> struct aspeed_mdio {
> void __iomem *base;
> + struct reset_control *reset;
> };
>
> static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
> @@ -120,6 +122,12 @@ static int aspeed_mdio_probe(struct platform_device *pdev)
> if (IS_ERR(ctx->base))
> return PTR_ERR(ctx->base);
>
> + ctx->reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
> + if (IS_ERR(ctx->reset))
> + return PTR_ERR(ctx->reset);
> +
> + reset_control_deassert(ctx->reset);
> +
> bus->name = DRV_NAME;
> snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id);
> bus->parent = &pdev->dev;
> @@ -129,6 +137,7 @@ static int aspeed_mdio_probe(struct platform_device *pdev)
> rc = of_mdiobus_register(bus, pdev->dev.of_node);
> if (rc) {
> dev_err(&pdev->dev, "Cannot register MDIO bus!\n");
> + reset_control_assert(ctx->reset);
> return rc;
> }
>
> @@ -139,7 +148,11 @@ static int aspeed_mdio_probe(struct platform_device *pdev)
>
> static int aspeed_mdio_remove(struct platform_device *pdev)
> {
> - mdiobus_unregister(platform_get_drvdata(pdev));
> + struct mii_bus *bus = (struct mii_bus *)platform_get_drvdata(pdev);
> + struct aspeed_mdio *ctx = bus->priv;
> +
> + reset_control_assert(ctx->reset);
Isn't this unnecessary because you've used the devm_ variant to acquire
the reset?
Andrew
