net: stmmac: Enable SERDES power up/down sequence

This patch is to enable Intel SERDES power up/down sequence. The SERDES
converts 8/10 bits data to SGMII signal. Below is an example of
HW configuration for SGMII mode. The SERDES is located in the PHY IF
in the diagram below.

<-----------------GBE Controller---------->|<--External PHY chip-->
+----------+         +----+            +---+           +----------+
|   EQoS   | <-GMII->| DW | < ------ > |PHY| <-SGMII-> | External |
|   MAC    |         |xPCS|            |IF |           | PHY      |
+----------+         +----+            +---+           +----------+
       ^               ^                 ^                ^
       |               |                 |                |
       +---------------------MDIO-------------------------+

PHY IF configuration and status registers are accessible through
mdio address 0x15 which is defined as mdio_adhoc_addr. During D0,
The driver will need to power up PHY IF by changing the power state
to P0. Likewise, for D3, the driver sets PHY IF power state to P3.

Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h
new file mode 100644
index 000000000000..e723096c0b15
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2020, Intel Corporation
+ * DWMAC Intel header file
+ */
+
+#ifndef __DWMAC_INTEL_H__
+#define __DWMAC_INTEL_H__
+
+#define POLL_DELAY_US 8
+
+/* SERDES Register */
+#define SERDES_GSR0	0x5	/* Global Status Reg0 */
+#define SERDES_GCR0	0xb	/* Global Configuration Reg0 */
+
+/* SERDES defines */
+#define SERDES_PLL_CLK		BIT(0)		/* PLL clk valid signal */
+#define SERDES_RST		BIT(2)		/* Serdes Reset */
+#define SERDES_PWR_ST_MASK	GENMASK(6, 4)	/* Serdes Power state*/
+#define SERDES_PWR_ST_SHIFT	4
+#define SERDES_PWR_ST_P0	0x0
+#define SERDES_PWR_ST_P3	0x3
+
+#endif /* __DWMAC_INTEL_H__ */