[PATCH v2 2/3] net: mdio: add reset control for Aspeed MDIO

Dylan Hung
2022-03-21T09:56:53Z

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]. So devm_reset_control_get_shared is used in this
change.

Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
Cc: stable@vger.kernel.org
---
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..5bda48d7071d 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_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);
+ mdiobus_unregister(bus);

return 0;
}
--
2.25.1