[PATCH net] net: pcs: rzn1-miic: Reset PRCMD state before unprotect sequence

[Yoshihisa Yamamoto]

On RZ/T2H MIIC, writing 0x0000 to PRCMD resets the command state
machine to the IDLE state.

Reset PRCMD before issuing the unprotect sequence so that it always
starts from a known state, regardless of any previous PRCMD activity.

Signed-off-by: Yoshihisa Yamamoto yoshihisa.yamamoto.xn@xxxxxxxxxxx
---
drivers/net/pcs/pcs-rzn1-miic.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/pcs/pcs-rzn1-miic.c b/drivers/net/pcs/pcs-rzn1-miic.c
index 2b72fa98d..818756bb8 100644
--- a/drivers/net/pcs/pcs-rzn1-miic.c
+++ b/drivers/net/pcs/pcs-rzn1-miic.c
@@ -270,6 +270,9 @@ static struct miic_port *phylink_pcs_to_miic_port(struct phylink_pcs *pcs)

 static void miic_unlock_regs(struct miic *miic)
{
+            /* Reset PRCMD state before unprotect sequence */
+            writel(0x0000, miic->base + MIIC_PRCMD);
+
            /* Unprotect register writes */
            writel(0x00A5, miic->base + MIIC_PRCMD);
            writel(0x0001, miic->base + MIIC_PRCMD);
-- 
2.34.1