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path: root/drivers/net/mdio/mdio-mux-meson-gxl.c
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Diffstat (limited to 'drivers/net/mdio/mdio-mux-meson-gxl.c')
-rw-r--r--drivers/net/mdio/mdio-mux-meson-gxl.c164
1 files changed, 164 insertions, 0 deletions
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..76188575ca1f
--- /dev/null
+++ b/drivers/net/mdio/mdio-mux-meson-gxl.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Baylibre, SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ */
+
+#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 void 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(REG4_PWRUPRSTSIG, priv->regs + ETH_REG4);
+ writel(val, priv->regs + ETH_REG3);
+ mdelay(10);
+
+ /* NOTE: The HW kept the phy id configurable at runtime.
+ * The id below is arbitrary. It is the one used in the vendor code.
+ * The only constraint is that it must match the one in
+ * drivers/net/phy/meson-gxl.c to properly match the PHY.
+ */
+ writel(FIELD_PREP(REG2_PHYID, EPHY_GXL_ID),
+ priv->regs + ETH_REG2);
+
+ /* Enable the internal phy */
+ val |= REG3_PHYEN;
+ writel(val, priv->regs + ETH_REG3);
+ writel(0, priv->regs + ETH_REG4);
+
+ /* The phy needs a bit of time to power up */
+ mdelay(10);
+}
+
+static void gxl_enable_external_mdio(struct gxl_mdio_mux *priv)
+{
+ /* Reset the mdio bus mux to the external phy */
+ writel(0, priv->regs + ETH_REG3);
+}
+
+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:
+ gxl_enable_external_mdio(priv);
+ break;
+ case MESON_GXL_MDIO_INTERNAL_ID:
+ gxl_enable_internal_mdio(priv);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+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 gxl_mdio_mux *priv;
+ struct clk *rclk;
+ 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@baylibre.com>");
+MODULE_LICENSE("GPL");