net: stmmac: Add support for optional reset control
The DWMAC has a reset assert line, which is used on some SoCs. Add an
optional reset control to stmmac driver core.
To support reset control deferred probing, this patch changes the driver
probe function to return the actual error, instead of just -EINVAL.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0d2c4cb..0c5c120 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -51,6 +51,7 @@
#include <linux/net_tstamp.h>
#include "stmmac_ptp.h"
#include "stmmac.h"
+#include <linux/reset.h>
#define STMMAC_ALIGN(x) L1_CACHE_ALIGN(x)
#define JUMBO_LEN 9000
@@ -2728,10 +2729,24 @@
if (IS_ERR(priv->stmmac_clk)) {
dev_warn(priv->device, "%s: warning: cannot get CSR clock\n",
__func__);
+ ret = PTR_ERR(priv->stmmac_clk);
goto error_clk_get;
}
clk_prepare_enable(priv->stmmac_clk);
+ priv->stmmac_rst = devm_reset_control_get(priv->device,
+ STMMAC_RESOURCE_NAME);
+ if (IS_ERR(priv->stmmac_rst)) {
+ if (PTR_ERR(priv->stmmac_rst) == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto error_hw_init;
+ }
+ dev_info(priv->device, "no reset control found\n");
+ priv->stmmac_rst = NULL;
+ }
+ if (priv->stmmac_rst)
+ reset_control_deassert(priv->stmmac_rst);
+
/* Init MAC and get the capabilities */
ret = stmmac_hw_init(priv);
if (ret)
@@ -2808,7 +2823,7 @@
error_clk_get:
free_netdev(ndev);
- return NULL;
+ return ERR_PTR(ret);
}
/**
@@ -2832,6 +2847,8 @@
stmmac_mdio_unregister(ndev);
netif_carrier_off(ndev);
unregister_netdev(ndev);
+ if (priv->stmmac_rst)
+ reset_control_assert(priv->stmmac_rst);
clk_disable_unprepare(priv->stmmac_clk);
free_netdev(ndev);