[PATCH net-next 2/2] net: mdio: add amlogic gxl mdio mux support

From: Jerome Brunet
Date: Mon Jan 16 2023 - 04:17:31 EST


Add support for the mdio mux and internal phy glue of the GXL SoC
family

Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
drivers/net/mdio/Kconfig | 11 ++
drivers/net/mdio/Makefile | 1 +
drivers/net/mdio/mdio-mux-meson-gxl.c | 160 ++++++++++++++++++++++++++
3 files changed, 172 insertions(+)
create mode 100644 drivers/net/mdio/mdio-mux-meson-gxl.c

diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig
index bfa16826a6e1..80f3e10b1be1 100644
--- a/drivers/net/mdio/Kconfig
+++ b/drivers/net/mdio/Kconfig
@@ -215,6 +215,17 @@ config MDIO_BUS_MUX_MESON_G12A
the amlogic g12a SoC. The multiplexers connects either the external
or the internal MDIO bus to the parent bus.

+config MDIO_BUS_MUX_MESON_GXL
+ tristate "Amlogic GXL based MDIO bus multiplexer"
+ depends on ARCH_MESON || COMPILE_TEST
+ depends on OF_MDIO && HAS_IOMEM && COMMON_CLK
+ select MDIO_BUS_MUX
+ default m if ARCH_MESON
+ help
+ This module provides a driver for the MDIO multiplexer/glue of
+ the amlogic gxl SoC. The multiplexers connects either the external
+ or the internal MDIO bus to the parent bus.
+
config MDIO_BUS_MUX_BCM6368
tristate "Broadcom BCM6368 MDIO bus multiplexers"
depends on OF && OF_MDIO && (BMIPS_GENERIC || COMPILE_TEST)
diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile
index 15f8dc4042ce..7d4cb4c11e4e 100644
--- a/drivers/net/mdio/Makefile
+++ b/drivers/net/mdio/Makefile
@@ -28,5 +28,6 @@ obj-$(CONFIG_MDIO_BUS_MUX_BCM6368) += mdio-mux-bcm6368.o
obj-$(CONFIG_MDIO_BUS_MUX_BCM_IPROC) += mdio-mux-bcm-iproc.o
obj-$(CONFIG_MDIO_BUS_MUX_GPIO) += mdio-mux-gpio.o
obj-$(CONFIG_MDIO_BUS_MUX_MESON_G12A) += mdio-mux-meson-g12a.o
+obj-$(CONFIG_MDIO_BUS_MUX_MESON_GXL) += mdio-mux-meson-gxl.o
obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) += mdio-mux-mmioreg.o
obj-$(CONFIG_MDIO_BUS_MUX_MULTIPLEXER) += mdio-mux-multiplexer.o
diff --git a/drivers/net/mdio/mdio-mux-meson-gxl.c b/drivers/net/mdio/mdio-mux-meson-gxl.c
new file mode 100644
index 000000000000..205095d845ea
--- /dev/null
+++ b/drivers/net/mdio/mdio-mux-meson-gxl.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Baylibre, SAS.
+ * Author: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/mdio-mux.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define ETH_REG2 0x0
+#define REG2_PHYID GENMASK(21, 0)
+#define EPHY_GXL_ID 0x110181
+#define REG2_LEDACT GENMASK(23, 22)
+#define REG2_LEDLINK GENMASK(25, 24)
+#define REG2_DIV4SEL BIT(27)
+#define REG2_ADCBYPASS BIT(30)
+#define REG2_CLKINSEL BIT(31)
+#define ETH_REG3 0x4
+#define REG3_ENH BIT(3)
+#define REG3_CFGMODE GENMASK(6, 4)
+#define REG3_AUTOMDIX BIT(7)
+#define REG3_PHYADDR GENMASK(12, 8)
+#define REG3_PWRUPRST BIT(21)
+#define REG3_PWRDOWN BIT(22)
+#define REG3_LEDPOL BIT(23)
+#define REG3_PHYMDI BIT(26)
+#define REG3_CLKINEN BIT(29)
+#define REG3_PHYIP BIT(30)
+#define REG3_PHYEN BIT(31)
+#define ETH_REG4 0x8
+#define REG4_PWRUPRSTSIG BIT(0)
+
+#define MESON_GXL_MDIO_EXTERNAL_ID 0
+#define MESON_GXL_MDIO_INTERNAL_ID 1
+
+struct gxl_mdio_mux {
+ void __iomem *regs;
+ void *mux_handle;
+};
+
+static int gxl_enable_internal_mdio(struct gxl_mdio_mux *priv)
+{
+ u32 val;
+
+ /* Setup the internal phy */
+ val = (REG3_ENH |
+ FIELD_PREP(REG3_CFGMODE, 0x7) |
+ REG3_AUTOMDIX |
+ FIELD_PREP(REG3_PHYADDR, 8) |
+ REG3_LEDPOL |
+ REG3_PHYMDI |
+ REG3_CLKINEN |
+ REG3_PHYIP);
+
+ writel_relaxed(REG4_PWRUPRSTSIG, priv->regs + ETH_REG4);
+ writel_relaxed(val, priv->regs + ETH_REG3);
+ mdelay(10);
+
+ /* Set the internal phy id */
+ writel_relaxed(FIELD_PREP(REG2_PHYID, 0x110181),
+ priv->regs + ETH_REG2);
+
+ /* Enable the internal phy */
+ val |= REG3_PHYEN;
+ writel_relaxed(val, priv->regs + ETH_REG3);
+ writel_relaxed(0, priv->regs + ETH_REG4);
+
+ /* The phy needs a bit of time to come up */
+ mdelay(10);
+
+ return 0;
+}
+
+static int gxl_enable_external_mdio(struct gxl_mdio_mux *priv)
+{
+ /* Reset the mdio bus mux to the external phy */
+ writel_relaxed(0, priv->regs + ETH_REG3);
+
+ return 0;
+}
+
+static int gxl_mdio_switch_fn(int current_child, int desired_child,
+ void *data)
+{
+ struct gxl_mdio_mux *priv = dev_get_drvdata(data);
+
+ if (current_child == desired_child)
+ return 0;
+
+ switch (desired_child) {
+ case MESON_GXL_MDIO_EXTERNAL_ID:
+ return gxl_enable_external_mdio(priv);
+ case MESON_GXL_MDIO_INTERNAL_ID:
+ return gxl_enable_internal_mdio(priv);
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct of_device_id gxl_mdio_mux_match[] = {
+ { .compatible = "amlogic,gxl-mdio-mux", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, gxl_mdio_mux_match);
+
+
+static int gxl_mdio_mux_probe(struct platform_device *pdev){
+ struct device *dev = &pdev->dev;
+ struct clk *rclk;
+ struct gxl_mdio_mux *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, priv);
+
+ priv->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->regs))
+ return PTR_ERR(priv->regs);
+
+ rclk = devm_clk_get_enabled(dev, "ref");
+ if (IS_ERR(rclk))
+ return dev_err_probe(dev, PTR_ERR(rclk),
+ "failed to get reference clock\n");
+
+ ret = mdio_mux_init(dev, dev->of_node, gxl_mdio_switch_fn,
+ &priv->mux_handle, dev, NULL);
+ if (ret)
+ dev_err_probe(dev, ret, "mdio multiplexer init failed\n");
+
+ return ret;
+}
+
+static int gxl_mdio_mux_remove(struct platform_device *pdev)
+{
+ struct gxl_mdio_mux *priv = platform_get_drvdata(pdev);
+
+ mdio_mux_uninit(priv->mux_handle);
+
+ return 0;
+}
+
+static struct platform_driver gxl_mdio_mux_driver = {
+ .probe = gxl_mdio_mux_probe,
+ .remove = gxl_mdio_mux_remove,
+ .driver = {
+ .name = "gxl-mdio-mux",
+ .of_match_table = gxl_mdio_mux_match,
+ },
+};
+module_platform_driver(gxl_mdio_mux_driver);
+
+MODULE_DESCRIPTION("Amlogic GXL MDIO multiplexer driver");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@xxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.39.0