From 7865ad6551c92779f309ef9e433dd6a00c7aeda7 Mon Sep 17 00:00:00 2001 From: Pankaj Bansal Date: Mon, 25 Feb 2019 06:16:55 +0000 Subject: drivers: net: phy: mdio-mux: Add support for Generic Mux controls Add support for Generic Mux controls, when Mdio mux node is a consumer of mux produced by some other device. Signed-off-by: Pankaj Bansal Signed-off-by: David S. Miller --- drivers/net/phy/Kconfig | 12 ++++ drivers/net/phy/Makefile | 1 + drivers/net/phy/mdio-mux-multiplexer.c | 122 +++++++++++++++++++++++++++++++++ 3 files changed, 135 insertions(+) create mode 100644 drivers/net/phy/mdio-mux-multiplexer.c (limited to 'drivers/net/phy') diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig index 3d187cd50eb0..7f66af446ec7 100644 --- a/drivers/net/phy/Kconfig +++ b/drivers/net/phy/Kconfig @@ -87,6 +87,18 @@ config MDIO_BUS_MUX_MMIOREG Currently, only 8/16/32 bits registers are supported. +config MDIO_BUS_MUX_MULTIPLEXER + tristate "MDIO bus multiplexer using kernel multiplexer subsystem" + depends on OF + select MULTIPLEXER + select MDIO_BUS_MUX + help + This module provides a driver for MDIO bus multiplexer + that is controlled via the kernel multiplexer subsystem. The + bus multiplexer connects one of several child MDIO busses to + a parent bus. Child bus selection is under the control of + the kernel multiplexer subsystem. + config MDIO_CAVIUM tristate diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile index 73e9670ef7e0..ece5dae67174 100644 --- a/drivers/net/phy/Makefile +++ b/drivers/net/phy/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o obj-$(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_MMIOREG) += mdio-mux-mmioreg.o +obj-$(CONFIG_MDIO_BUS_MUX_MULTIPLEXER) += mdio-mux-multiplexer.o obj-$(CONFIG_MDIO_CAVIUM) += mdio-cavium.o obj-$(CONFIG_MDIO_GPIO) += mdio-gpio.o obj-$(CONFIG_MDIO_HISI_FEMAC) += mdio-hisi-femac.o diff --git a/drivers/net/phy/mdio-mux-multiplexer.c b/drivers/net/phy/mdio-mux-multiplexer.c new file mode 100644 index 000000000000..d6564381aa3e --- /dev/null +++ b/drivers/net/phy/mdio-mux-multiplexer.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* MDIO bus multiplexer using kernel multiplexer subsystem + * + * Copyright 2019 NXP + */ + +#include +#include +#include +#include + +struct mdio_mux_multiplexer_state { + struct mux_control *muxc; + bool do_deselect; + void *mux_handle; +}; + +/** + * mdio_mux_multiplexer_switch_fn - This function is called by the mdio-mux + * layer when it thinks the mdio bus + * multiplexer needs to switch. + * @current_child: current value of the mux register. + * @desired_child: value of the 'reg' property of the target child MDIO node. + * @data: Private data used by this switch_fn passed to mdio_mux_init function + * via mdio_mux_init(.., .., .., .., data, ..). + * + * The first time this function is called, current_child == -1. + * If current_child == desired_child, then the mux is already set to the + * correct bus. + */ +static int mdio_mux_multiplexer_switch_fn(int current_child, int desired_child, + void *data) +{ + struct platform_device *pdev; + struct mdio_mux_multiplexer_state *s; + int ret = 0; + + pdev = (struct platform_device *)data; + s = platform_get_drvdata(pdev); + + if (!(current_child ^ desired_child)) + return 0; + + if (s->do_deselect) + ret = mux_control_deselect(s->muxc); + if (ret) { + dev_err(&pdev->dev, "mux_control_deselect failed in %s: %d\n", + __func__, ret); + return ret; + } + + ret = mux_control_select(s->muxc, desired_child); + if (!ret) { + dev_dbg(&pdev->dev, "%s %d -> %d\n", __func__, current_child, + desired_child); + s->do_deselect = true; + } else { + s->do_deselect = false; + } + + return ret; +} + +static int mdio_mux_multiplexer_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mdio_mux_multiplexer_state *s; + int ret = 0; + + s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + s->muxc = devm_mux_control_get(dev, NULL); + if (IS_ERR(s->muxc)) { + ret = PTR_ERR(s->muxc); + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "Failed to get mux: %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, s); + + ret = mdio_mux_init(&pdev->dev, pdev->dev.of_node, + mdio_mux_multiplexer_switch_fn, &s->mux_handle, + pdev, NULL); + + return ret; +} + +static int mdio_mux_multiplexer_remove(struct platform_device *pdev) +{ + struct mdio_mux_multiplexer_state *s = platform_get_drvdata(pdev); + + mdio_mux_uninit(s->mux_handle); + + if (s->do_deselect) + mux_control_deselect(s->muxc); + + return 0; +} + +static const struct of_device_id mdio_mux_multiplexer_match[] = { + { .compatible = "mdio-mux-multiplexer", }, + {}, +}; +MODULE_DEVICE_TABLE(of, mdio_mux_multiplexer_match); + +static struct platform_driver mdio_mux_multiplexer_driver = { + .driver = { + .name = "mdio-mux-multiplexer", + .of_match_table = mdio_mux_multiplexer_match, + }, + .probe = mdio_mux_multiplexer_probe, + .remove = mdio_mux_multiplexer_remove, +}; + +module_platform_driver(mdio_mux_multiplexer_driver); + +MODULE_DESCRIPTION("MDIO bus multiplexer using kernel multiplexer subsystem"); +MODULE_AUTHOR("Pankaj Bansal "); +MODULE_LICENSE("GPL"); -- cgit v1.2.3