diff options
Diffstat (limited to 'drivers/net/mdio/mdio-mux-meson-gxl.c')
| -rw-r--r-- | drivers/net/mdio/mdio-mux-meson-gxl.c | 164 |
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 0000000000..76188575ca --- /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"); |