Re: [PATCH RFT net-next 02/10] net: stmmac: Add support for Allwinner A523 GMAC200

From: Yanteng Si
Date: Tue Jul 01 2025 - 22:00:33 EST


在 7/2/25 12:57 AM, Chen-Yu Tsai 写道:
From: Chen-Yu Tsai <wens@xxxxxxxx>

The Allwinner A523 SoC family has a second Ethernet controller, called
the GMAC200 in the BSP and T527 datasheet, and referred to as GMAC1 for
numbering. This controller, according to BSP sources, is fully
compatible with a slightly newer version of the Synopsys DWMAC core.
The glue layer around the controller is the same as found around older
DWMAC cores on Allwinner SoCs. The only slight difference is that since
this is the second controller on the SoC, the register for the clock
delay controls is at a different offset. Last, the integration includes
a dedicated clock gate for the memory bus and the whole thing is put in
a separately controllable power domain.

Add a new driver for this hardware supporting the integration layer.

Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/Kconfig | 12 ++
drivers/net/ethernet/stmicro/stmmac/Makefile | 1 +
.../ethernet/stmicro/stmmac/dwmac-sun55i.c | 161 ++++++++++++++++++
3 files changed, 174 insertions(+)
create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-sun55i.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 67fa879b1e52..38ce9a0cfb5b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -263,6 +263,18 @@ config DWMAC_SUN8I
stmmac device driver. This driver is used for H3/A83T/A64
EMAC ethernet controller.
+config DWMAC_SUN55I
+ tristate "Allwinner sun55i GMAC200 support"
+ default ARCH_SUNXI
+ depends on OF && (ARCH_SUNXI || COMPILE_TEST)
+ select MDIO_BUS_MUX
+ help
+ Support for Allwinner A523/T527 GMAC200 ethernet controllers.
+
+ This selects Allwinner SoC glue layer support for the
+ stmmac device driver. This driver is used for A523/T527
+ GMAC200 ethernet controller.
+
config DWMAC_THEAD
tristate "T-HEAD dwmac support"
depends on OF && (ARCH_THEAD || COMPILE_TEST)
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index b591d93f8503..51e068e26ce4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_DWMAC_STI) += dwmac-sti.o
obj-$(CONFIG_DWMAC_STM32) += dwmac-stm32.o
obj-$(CONFIG_DWMAC_SUNXI) += dwmac-sunxi.o
obj-$(CONFIG_DWMAC_SUN8I) += dwmac-sun8i.o
+obj-$(CONFIG_DWMAC_SUN55I) += dwmac-sun55i.o
obj-$(CONFIG_DWMAC_THEAD) += dwmac-thead.o
obj-$(CONFIG_DWMAC_DWC_QOS_ETH) += dwmac-dwc-qos-eth.o
obj-$(CONFIG_DWMAC_INTEL_PLAT) += dwmac-intel-plat.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun55i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun55i.c
new file mode 100644
index 000000000000..7fadb90e3098
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun55i.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * dwmac-sun55i.c - Allwinner sun55i GMAC200 specific glue layer
+ *
+ * Copyright (C) 2025 Chen-Yu Tsai <wens@xxxxxxxx>
+ *
+ * syscon parts taken from dwmac-sun8i.c, which is
+ *
+ * Copyright (C) 2017 Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/stmmac.h>
+
+#include "stmmac.h"
+#include "stmmac_platform.h"
+
+#define SYSCON_REG 0x34
+
+/* RMII specific bits */
+#define SYSCON_RMII_EN BIT(13) /* 1: enable RMII (overrides EPIT) */
insert a blankline.
+/* Generic system control EMAC_CLK bits */
+#define SYSCON_ETXDC_MASK GENMASK(12, 10)
+#define SYSCON_ERXDC_MASK GENMASK(9, 5)
ditto.
+/* EMAC PHY Interface Type */
+#define SYSCON_EPIT BIT(2) /* 1: RGMII, 0: MII */
+#define SYSCON_ETCS_MASK GENMASK(1, 0)
+#define SYSCON_ETCS_MII 0x0
+#define SYSCON_ETCS_EXT_GMII 0x1
+#define SYSCON_ETCS_INT_GMII 0x2
+
+#define MASK_TO_VAL(mask) ((mask) >> (__builtin_ffsll(mask) - 1))
+
+static int sun55i_gmac200_set_syscon(struct device *dev,
+ struct plat_stmmacenet_data *plat)
+{
+ struct device_node *node = dev->of_node;
+ struct regmap *regmap;
+ u32 val, reg = 0;
+
+ regmap = syscon_regmap_lookup_by_phandle(node, "syscon");
+ if (IS_ERR(regmap))
+ return dev_err_probe(dev, PTR_ERR(regmap), "Unable to map syscon\n");
+
-----------
+ if (!of_property_read_u32(node, "allwinner,tx-delay-ps", &val)) {
+ if (val % 100) {
+ dev_err(dev, "tx-delay must be a multiple of 100\n");
+ return -EINVAL;
+ }
+ val /= 100;
+ dev_dbg(dev, "set tx-delay to %x\n", val);
+ if (val > MASK_TO_VAL(SYSCON_ETXDC_MASK))
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid TX clock delay: %d\n",
+ val);
+
+ reg |= FIELD_PREP(SYSCON_ETXDC_MASK, val);
+ }
+
+ if (!of_property_read_u32(node, "allwinner,rx-delay-ps", &val)) {
+ if (val % 100) {
+ dev_err(dev, "rx-delay must be a multiple of 100\n");
+ return -EINVAL;
+ }
+ val /= 100;
+ dev_dbg(dev, "set rx-delay to %x\n", val);
+ if (val > MASK_TO_VAL(SYSCON_ERXDC_MASK))
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid RX clock delay: %d\n",
+ val);
+
+ reg |= FIELD_PREP(SYSCON_ERXDC_MASK, val);
+ }
------------
These two parts of the code are highly similar.
Can you construct a separate function?
+
+ switch (plat->mac_interface) {

+ case PHY_INTERFACE_MODE_MII:
+ /* default */
+ break;
This line of comment seems a bit abrupt here.


Thanks,
Yanteng