Merge branch 'net-stmmac-cleanup-transmit-clock-setting'

Russell King says:

====================
net: stmmac: cleanup transmit clock setting

A lot of stmmac platform code which sets the transmit clock is very
similar - they decode the speed to the clock rate (125, 25 or 2.5 MHz)
and then set a clock to that rate.

The DWMAC core appears to have a clock input for the transmit section
called clk_tx_i which requires this rate.

This series moves the code which sets this clock into the core stmmac
code.

Patch 1 adds a hook that platforms can use to configure the clock rate.
Patch 2 adds a generic implementation.
The remainder of the patches convert the glue code for various platforms
to use this new infrastructure.
====================

Link: https://patch.msgid.link/Z8AtX-wyPal1auVO@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 424fa2fe31c6..aec230353ac4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -178,6 +178,38 @@ int stmmac_bus_clks_config(struct stmmac_priv *priv, bool enabled)
 EXPORT_SYMBOL_GPL(stmmac_bus_clks_config);
 
 /**
+ * stmmac_set_clk_tx_rate() - set the clock rate for the MAC transmit clock
+ * @bsp_priv: BSP private data structure (unused)
+ * @clk_tx_i: the transmit clock
+ * @interface: the selected interface mode
+ * @speed: the speed that the MAC will be operating at
+ *
+ * Set the transmit clock rate for the MAC, normally 2.5MHz for 10Mbps,
+ * 25MHz for 100Mbps and 125MHz for 1Gbps. This is suitable for at least
+ * MII, GMII, RGMII and RMII interface modes. Platforms can hook this into
+ * the plat_data->set_clk_tx_rate method directly, call it via their own
+ * implementation, or implement their own method should they have more
+ * complex requirements. It is intended to only be used in this method.
+ *
+ * plat_data->clk_tx_i must be filled in.
+ */
+int stmmac_set_clk_tx_rate(void *bsp_priv, struct clk *clk_tx_i,
+			   phy_interface_t interface, int speed)
+{
+	long rate = rgmii_clock(speed);
+
+	/* Silently ignore unsupported speeds as rgmii_clock() only
+	 * supports 10, 100 and 1000Mbps. We do not want to spit
+	 * errors for 2500 and higher speeds here.
+	 */
+	if (rate < 0)
+		return 0;
+
+	return clk_set_rate(clk_tx_i, rate);
+}
+EXPORT_SYMBOL_GPL(stmmac_set_clk_tx_rate);
+
+/**
  * stmmac_verify_args - verify the driver parameters.
  * Description: it checks the driver parameters and set a default in case of
  * errors.
@@ -928,6 +960,7 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 	struct stmmac_priv *priv = netdev_priv(to_net_dev(config->dev));
 	unsigned int flow_ctrl;
 	u32 old_ctrl, ctrl;
+	int ret;
 
 	if ((priv->plat->flags & STMMAC_FLAG_SERDES_UP_AFTER_PHY_LINKUP) &&
 	    priv->plat->serdes_powerup)
@@ -1020,6 +1053,16 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 	if (ctrl != old_ctrl)
 		writel(ctrl, priv->ioaddr + MAC_CTRL_REG);
 
+	if (priv->plat->set_clk_tx_rate) {
+		ret = priv->plat->set_clk_tx_rate(priv->plat->bsp_priv,
+						priv->plat->clk_tx_i,
+						interface, speed);
+		if (ret < 0)
+			netdev_err(priv->dev,
+				   "failed to configure transmit clock for %dMbps: %pe\n",
+				   speed, ERR_PTR(ret));
+	}
+
 	stmmac_mac_set(priv, priv->ioaddr, true);
 	if (priv->dma_cap.eee)
 		stmmac_set_eee_pls(priv, priv->hw, true);