[PATCH 08/12] net: stmmac: Add glue layer for StarFive JH7100 SoC

From: Cristian Ciocaltea
Date: Fri Feb 10 2023 - 22:19:45 EST

From: Emil Renner Berthing <kernel@xxxxxxxx>

This adds a glue layer for the Synopsys DesignWare MAC IP core on the
StarFive JH7100 SoC.

Signed-off-by: Emil Renner Berthing <kernel@xxxxxxxx>
[drop references to JH7110, update JH7100 compatible string]
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/net/ethernet/stmicro/stmmac/Kconfig | 12 ++
drivers/net/ethernet/stmicro/stmmac/Makefile | 1 +
.../ethernet/stmicro/stmmac/dwmac-starfive.c | 155 ++++++++++++++++++
4 files changed, 169 insertions(+)
create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d48468b81b94..defedaff6041 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19820,6 +19820,7 @@ STARFIVE DWMAC GLUE LAYER
M: Emil Renner Berthing <kernel@xxxxxxxx>
S: Maintained
F: Documentation/devicetree/bindings/net/starfive,jh7100-dwmac.yaml
+F: drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c

STARFIVE JH7100 CLOCK DRIVERS
M: Emil Renner Berthing <kernel@xxxxxxxx>
diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index f77511fe4e87..2c81aa594291 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -165,6 +165,18 @@ config DWMAC_SOCFPGA
for the stmmac device driver. This driver is used for
arria5 and cyclone5 FPGA SoCs.

+config DWMAC_STARFIVE
+ tristate "StarFive DWMAC support"
+ default m if SOC_STARFIVE
+ depends on SOC_STARFIVE || COMPILE_TEST
+ select MFD_SYSCON
+ help
+ Support for ethernet controller on StarFive SOCs.
+
+ This selects StarFive SoC glue layer support for the stmmac device
+ driver. This driver is used for the JH71x0 series GMAC ethernet
+ controller.
+
config DWMAC_STI
tristate "STi GMAC support"
default ARCH_STI
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 057e4bab5c08..8738fdbb4b2d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_DWMAC_OXNAS) += dwmac-oxnas.o
obj-$(CONFIG_DWMAC_QCOM_ETHQOS) += dwmac-qcom-ethqos.o
obj-$(CONFIG_DWMAC_ROCKCHIP) += dwmac-rk.o
obj-$(CONFIG_DWMAC_SOCFPGA) += dwmac-altr-socfpga.o
+obj-$(CONFIG_DWMAC_STARFIVE) += dwmac-starfive.o
obj-$(CONFIG_DWMAC_STI) += dwmac-sti.o
obj-$(CONFIG_DWMAC_STM32) += dwmac-stm32.o
obj-$(CONFIG_DWMAC_SUNXI) += dwmac-sunxi.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
new file mode 100644
index 000000000000..d4c81f1a5482
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dwmac-starfive.c - DWMAC glue layer for StarFive JH7100 SoC
+ *
+ * Copyright (C) 2021 Emil Renner Berthing <kernel@xxxxxxxx>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "stmmac.h"
+#include "stmmac_platform.h"
+
+#define JH7100_SYSMAIN_REGISTER28 0x70
+/* The value below is not a typo, just really bad naming by StarFive ¯\_(ツ)_/¯ */
+#define JH7100_SYSMAIN_REGISTER49 0xc8
+
+struct dwmac_starfive {
+ struct device *dev;
+ struct clk *gtxc;
+};
+
+static int dwmac_starfive_jh7100_syscon_init(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct regmap *sysmain;
+ u32 gtxclk_dlychain;
+ int ret;
+
+ sysmain = syscon_regmap_lookup_by_phandle(np, "starfive,syscon");
+ if (IS_ERR(sysmain))
+ return dev_err_probe(dev, PTR_ERR(sysmain),
+ "error getting sysmain registers\n");
+
+ /* Choose RGMII interface to the phy.
+ * TODO: support other interfaces once we know the meaning of other
+ * values in the register
+ */
+ ret = regmap_update_bits(sysmain, JH7100_SYSMAIN_REGISTER28, 0x7, 1);
+ if (ret)
+ return dev_err_probe(dev, ret, "error selecting gmac interface\n");
+
+ if (!of_property_read_u32(np, "starfive,gtxclk-dlychain", &gtxclk_dlychain)) {
+ ret = regmap_write(sysmain, JH7100_SYSMAIN_REGISTER49, gtxclk_dlychain);
+ if (ret)
+ return dev_err_probe(dev, ret, "error selecting gtxclk delay chain\n");
+ }
+
+ return 0;
+}
+
+static void dwmac_starfive_fix_mac_speed(void *data, unsigned int speed)
+{
+ struct dwmac_starfive *dwmac = data;
+ unsigned long rate;
+ int ret;
+
+ switch (speed) {
+ case SPEED_1000:
+ rate = 125000000;
+ break;
+ case SPEED_100:
+ rate = 25000000;
+ break;
+ case SPEED_10:
+ rate = 2500000;
+ break;
+ default:
+ dev_warn(dwmac->dev, "unsupported link speed %u\n", speed);
+ return;
+ }
+
+ ret = clk_set_rate(dwmac->gtxc, rate);
+ if (ret)
+ dev_err(dwmac->dev, "error setting gtx clock rate: %d\n", ret);
+}
+
+static int dwmac_starfive_probe(struct platform_device *pdev)
+{
+ struct stmmac_resources stmmac_res;
+ struct plat_stmmacenet_data *plat;
+ struct dwmac_starfive *dwmac;
+ struct clk *txclk;
+ int (*syscon_init)(struct device *dev);
+ int ret;
+
+ dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+ if (!dwmac)
+ return -ENOMEM;
+
+ ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+ if (ret)
+ return ret;
+
+ syscon_init = of_device_get_match_data(&pdev->dev);
+ if (syscon_init) {
+ ret = syscon_init(&pdev->dev);
+ if (ret)
+ return ret;
+ }
+
+ dwmac->gtxc = devm_clk_get_enabled(&pdev->dev, "gtxc");
+ if (IS_ERR(dwmac->gtxc))
+ return dev_err_probe(&pdev->dev, PTR_ERR(dwmac->gtxc),
+ "error getting/enabling gtxc clock\n");
+
+ txclk = devm_clk_get_enabled(&pdev->dev, "tx");
+ if (IS_ERR(txclk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(txclk),
+ "error getting/enabling tx clock\n");
+
+ plat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
+ if (IS_ERR(plat))
+ return dev_err_probe(&pdev->dev, PTR_ERR(plat),
+ "dt configuration failed\n");
+
+ dwmac->dev = &pdev->dev;
+ plat->bsp_priv = dwmac;
+ plat->fix_mac_speed = dwmac_starfive_fix_mac_speed;
+
+ ret = stmmac_dvr_probe(&pdev->dev, plat, &stmmac_res);
+ if (ret) {
+ stmmac_remove_config_dt(pdev, plat);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id dwmac_starfive_match[] = {
+ {
+ .compatible = "starfive,jh7100-dwmac",
+ .data = dwmac_starfive_jh7100_syscon_init,
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dwmac_starfive_match);
+
+static struct platform_driver dwmac_starfive_driver = {
+ .probe = dwmac_starfive_probe,
+ .remove = stmmac_pltfr_remove,
+ .driver = {
+ .name = "dwmac-starfive",
+ .pm = &stmmac_pltfr_pm_ops,
+ .of_match_table = dwmac_starfive_match,
+ },
+};
+module_platform_driver(dwmac_starfive_driver);
+
+MODULE_AUTHOR("Emil Renner Berthing <kernel@xxxxxxxx>");
+MODULE_DESCRIPTION("StarFive DWMAC Glue Layer");
+MODULE_LICENSE("GPL");
--
2.39.1