mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-18 18:57:47 +07:00
7865ad6551
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 <pankaj.bansal@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
123 lines
3.1 KiB
C
123 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/* MDIO bus multiplexer using kernel multiplexer subsystem
|
|
*
|
|
* Copyright 2019 NXP
|
|
*/
|
|
|
|
#include <linux/platform_device.h>
|
|
#include <linux/mdio-mux.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mux/consumer.h>
|
|
|
|
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 <pankaj.bansal@nxp.com>");
|
|
MODULE_LICENSE("GPL");
|