caa9b6b844
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Eventually after all drivers are converted, .remove_new() is renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/* MDIO bus multiplexer using kernel multiplexer subsystem
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*
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* Copyright 2019 NXP
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*/
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#include <linux/mdio-mux.h>
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#include <linux/module.h>
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#include <linux/mux/consumer.h>
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#include <linux/platform_device.h>
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struct mdio_mux_multiplexer_state {
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struct mux_control *muxc;
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bool do_deselect;
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void *mux_handle;
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};
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/**
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* mdio_mux_multiplexer_switch_fn - This function is called by the mdio-mux
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* layer when it thinks the mdio bus
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* multiplexer needs to switch.
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* @current_child: current value of the mux register.
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* @desired_child: value of the 'reg' property of the target child MDIO node.
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* @data: Private data used by this switch_fn passed to mdio_mux_init function
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* via mdio_mux_init(.., .., .., .., data, ..).
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*
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* The first time this function is called, current_child == -1.
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* If current_child == desired_child, then the mux is already set to the
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* correct bus.
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*/
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static int mdio_mux_multiplexer_switch_fn(int current_child, int desired_child,
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void *data)
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{
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struct platform_device *pdev;
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struct mdio_mux_multiplexer_state *s;
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int ret = 0;
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pdev = (struct platform_device *)data;
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s = platform_get_drvdata(pdev);
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if (!(current_child ^ desired_child))
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return 0;
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if (s->do_deselect)
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ret = mux_control_deselect(s->muxc);
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if (ret) {
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dev_err(&pdev->dev, "mux_control_deselect failed in %s: %d\n",
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__func__, ret);
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return ret;
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}
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ret = mux_control_select(s->muxc, desired_child);
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if (!ret) {
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dev_dbg(&pdev->dev, "%s %d -> %d\n", __func__, current_child,
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desired_child);
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s->do_deselect = true;
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} else {
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s->do_deselect = false;
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}
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return ret;
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}
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static int mdio_mux_multiplexer_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct mdio_mux_multiplexer_state *s;
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int ret = 0;
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s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
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if (!s)
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return -ENOMEM;
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s->muxc = devm_mux_control_get(dev, NULL);
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if (IS_ERR(s->muxc))
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return dev_err_probe(&pdev->dev, PTR_ERR(s->muxc),
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"Failed to get mux\n");
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platform_set_drvdata(pdev, s);
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ret = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
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mdio_mux_multiplexer_switch_fn, &s->mux_handle,
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pdev, NULL);
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return ret;
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}
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static void mdio_mux_multiplexer_remove(struct platform_device *pdev)
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{
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struct mdio_mux_multiplexer_state *s = platform_get_drvdata(pdev);
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mdio_mux_uninit(s->mux_handle);
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if (s->do_deselect)
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mux_control_deselect(s->muxc);
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}
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static const struct of_device_id mdio_mux_multiplexer_match[] = {
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{ .compatible = "mdio-mux-multiplexer", },
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{},
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};
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MODULE_DEVICE_TABLE(of, mdio_mux_multiplexer_match);
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static struct platform_driver mdio_mux_multiplexer_driver = {
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.driver = {
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.name = "mdio-mux-multiplexer",
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.of_match_table = mdio_mux_multiplexer_match,
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},
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.probe = mdio_mux_multiplexer_probe,
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.remove_new = mdio_mux_multiplexer_remove,
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};
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module_platform_driver(mdio_mux_multiplexer_driver);
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MODULE_DESCRIPTION("MDIO bus multiplexer using kernel multiplexer subsystem");
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MODULE_AUTHOR("Pankaj Bansal <pankaj.bansal@nxp.com>");
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MODULE_LICENSE("GPL");
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