[PATCH AUTOSEL 4.20 38/81] net: stmmac: Fallback to Platform Data clock in Watchdog conversion

[Sasha Levin <sashal@kernel.org>]

From: Jose Abreu <jose.abreu@synopsys.com>

[ Upstream commit 4ec5302fa906ec9d86597b236f62315bacdb9622 ]

If we don't have DT then stmmac_clk will not be available. Let's add a
new Platform Data field so that we can specify the refclk by this mean.

This way we can still use the coalesce command in PCI based setups.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../net/ethernet/stmicro/stmmac/stmmac_ethtool.c   | 14 ++++++++++----
 include/linux/stmmac.h                             |  1 +
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 9caf79ba5ef16..4d5fb4b51cc4f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -719,8 +719,11 @@ static u32 stmmac_usec2riwt(u32 usec, struct stmmac_priv *priv)
 {
 	unsigned long clk = clk_get_rate(priv->plat->stmmac_clk);
 
-	if (!clk)
-		return 0;
+	if (!clk) {
+		clk = priv->plat->clk_ref_rate;
+		if (!clk)
+			return 0;
+	}
 
 	return (usec * (clk / 1000000)) / 256;
 }
@@ -729,8 +732,11 @@ static u32 stmmac_riwt2usec(u32 riwt, struct stmmac_priv *priv)
 {
 	unsigned long clk = clk_get_rate(priv->plat->stmmac_clk);
 
-	if (!clk)
-		return 0;
+	if (!clk) {
+		clk = priv->plat->clk_ref_rate;
+		if (!clk)
+			return 0;
+	}
 
 	return (riwt * 256) / (clk / 1000000);
 }
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 7ddfc65586b04..4335bd771ce57 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -184,6 +184,7 @@ struct plat_stmmacenet_data {
 	struct clk *pclk;
 	struct clk *clk_ptp_ref;
 	unsigned int clk_ptp_rate;
+	unsigned int clk_ref_rate;
 	struct reset_control *stmmac_rst;
 	struct stmmac_axi *axi;
 	int has_gmac4;
-- 
2.19.1