[PATCH v2 1/3] net: stmmac: socfpga: add call to assert/deassert ahb reset line

[Dinh Nguyen]

The "stmmaceth-ocp" reset line of stmmac controller on the SoCFPGA
platform is essentially the "ahb" reset on the standard stmmac
controller. But since stmmaceth-ocp has already been introduced into
the wild, we cannot just remove support for it. But what we can do is
to support both "stmmaceth-ocp" and "ahb" reset names. Going forward we
will be using "ahb", but in order to not break ABI, we will be call reset
assert/de-assert both ahb and stmmaceth-ocp.

The ethernet hardware on SoCFPGA requires either the stmmaceth-ocp or
ahb reset to be asserted every time before changing the phy mode, then
de-asserted when the phy mode has been set.

With this change, we should be able to revert patch:
commit 62a40a0d5634 ("arm: dts: socfpga: use reset-name "stmmaceth-ocp"
instead of "ahb"")

Signed-off-by: Dinh Nguyen <dinguyen at kernel.org>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index a2b52d2c4eb6..79df55515c71 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -407,6 +407,7 @@ static int socfpga_gen5_set_phy_mode(struct socfpga_dwmac *dwmac)
 
 	/* Assert reset to the enet controller before changing the phy mode */
 	reset_control_assert(dwmac->stmmac_ocp_rst);
+	reset_control_assert(dwmac->plat_dat->stmmac_ahb_rst);
 	reset_control_assert(dwmac->stmmac_rst);
 
 	regmap_read(sys_mgr_base_addr, reg_offset, &ctrl);
@@ -436,6 +437,7 @@ static int socfpga_gen5_set_phy_mode(struct socfpga_dwmac *dwmac)
 	 * the enet controller, and operation to start in requested mode
 	 */
 	reset_control_deassert(dwmac->stmmac_ocp_rst);
+	reset_control_deassert(dwmac->plat_dat->stmmac_ahb_rst);
 	reset_control_deassert(dwmac->stmmac_rst);
 	if (phymode == PHY_INTERFACE_MODE_SGMII)
 		socfpga_sgmii_config(dwmac, true);
@@ -463,6 +465,7 @@ static int socfpga_gen10_set_phy_mode(struct socfpga_dwmac *dwmac)
 
 	/* Assert reset to the enet controller before changing the phy mode */
 	reset_control_assert(dwmac->stmmac_ocp_rst);
+	reset_control_assert(dwmac->plat_dat->stmmac_ahb_rst);
 	reset_control_assert(dwmac->stmmac_rst);
 
 	regmap_read(sys_mgr_base_addr, reg_offset, &ctrl);
@@ -489,6 +492,7 @@ static int socfpga_gen10_set_phy_mode(struct socfpga_dwmac *dwmac)
 	 * the enet controller, and operation to start in requested mode
 	 */
 	reset_control_deassert(dwmac->stmmac_ocp_rst);
+	reset_control_deassert(dwmac->plat_dat->stmmac_ahb_rst);
 	reset_control_deassert(dwmac->stmmac_rst);
 	if (phymode == PHY_INTERFACE_MODE_SGMII)
 		socfpga_sgmii_config(dwmac, true);

-- 
2.42.0.411.g813d9a9188