[PATCH 2/3] net: dwc_eth_qos_imx: Add platform specific reset for i.MX93

[Erik Schumacher]

The EQOS on i.MX93 fails to finish the reset procedure in RMII mode.
This is described in errata ERR051683. This patch implements the
provided workaround which sets the PS and FES bits after the SWR is set
by using the eqos_fix_soc_reset function.

Adapted from linux-kernel commit b536f32b5b03 ("net: stmmac: dwmac-imx:
use platform specific reset for imx93 SoCs")

Signed-off-by: Erik Schumacher <erik.schumacher at iris-sensing.com>
---
 drivers/net/dwc_eth_qos_imx.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/dwc_eth_qos_imx.c b/drivers/net/dwc_eth_qos_imx.c
index 642432834f..af42f7436c 100644
--- a/drivers/net/dwc_eth_qos_imx.c
+++ b/drivers/net/dwc_eth_qos_imx.c
@@ -216,6 +216,27 @@ static int eqos_get_enetaddr_imx(struct udevice *dev)
 	return 0;
 }
 
+static void eqos_fix_soc_reset_imx(struct udevice *dev)
+{
+	struct eqos_priv *eqos = dev_get_priv(dev);
+
+	if (IS_ENABLED(CONFIG_IMX93)) {
+		/*
+		 * Workaround for ERR051683 in i.MX93
+		 * The i.MX93 requires speed configuration bits to be set to
+		 * complete the reset procedure in RMII mode.
+		 * See b536f32b5b03 ("net: stmmac: dwmac-imx: use platform
+		 * specific reset for imx93 SoCs") in linux
+		 */
+		if (eqos->config->interface(dev) == PHY_INTERFACE_MODE_RMII) {
+			udelay(200);
+			setbits_le32(&eqos->mac_regs->configuration,
+				     EQOS_MAC_CONFIGURATION_PS |
+				     EQOS_MAC_CONFIGURATION_FES);
+		}
+	}
+}
+
 static struct eqos_ops eqos_imx_ops = {
 	.eqos_inval_desc = eqos_inval_desc_generic,
 	.eqos_flush_desc = eqos_flush_desc_generic,
@@ -232,6 +253,7 @@ static struct eqos_ops eqos_imx_ops = {
 	.eqos_set_tx_clk_speed = eqos_set_tx_clk_speed_imx,
 	.eqos_get_enetaddr = eqos_get_enetaddr_imx,
 	.eqos_get_tick_clk_rate = eqos_get_tick_clk_rate_imx,
+	.eqos_fix_soc_reset = eqos_fix_soc_reset_imx,
 };
 
 struct eqos_config __maybe_unused eqos_imx_config = {
-- 
2.47.0