1a0457ab2c
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() will be 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> Link: https://lore.kernel.org/r/20231104211501.3676352-25-u.kleine-koenig@pengutronix.de Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
132 lines
3.1 KiB
C
132 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* QNAP Turbo NAS Board power off. Can also be used on Synology devices.
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*
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* Copyright (C) 2012 Andrew Lunn <andrew@lunn.ch>
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*
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* Based on the code from:
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*
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* Copyright (C) 2009 Martin Michlmayr <tbm@cyrius.com>
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* Copyright (C) 2008 Byron Bradley <byron.bbradley@gmail.com>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/serial_reg.h>
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#include <linux/of.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#define UART1_REG(x) (base + ((UART_##x) << 2))
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struct power_off_cfg {
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u32 baud;
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char cmd;
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};
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static const struct power_off_cfg qnap_power_off_cfg = {
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.baud = 19200,
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.cmd = 'A',
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};
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static const struct power_off_cfg synology_power_off_cfg = {
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.baud = 9600,
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.cmd = '1',
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};
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static const struct of_device_id qnap_power_off_of_match_table[] = {
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{ .compatible = "qnap,power-off",
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.data = &qnap_power_off_cfg,
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},
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{ .compatible = "synology,power-off",
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.data = &synology_power_off_cfg,
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},
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{}
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};
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MODULE_DEVICE_TABLE(of, qnap_power_off_of_match_table);
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static void __iomem *base;
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static unsigned long tclk;
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static const struct power_off_cfg *cfg;
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static void qnap_power_off(void)
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{
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const unsigned divisor = ((tclk + (8 * cfg->baud)) / (16 * cfg->baud));
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pr_err("%s: triggering power-off...\n", __func__);
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/* hijack UART1 and reset into sane state */
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writel(0x83, UART1_REG(LCR));
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writel(divisor & 0xff, UART1_REG(DLL));
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writel((divisor >> 8) & 0xff, UART1_REG(DLM));
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writel(0x03, UART1_REG(LCR));
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writel(0x00, UART1_REG(IER));
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writel(0x00, UART1_REG(FCR));
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writel(0x00, UART1_REG(MCR));
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/* send the power-off command to PIC */
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writel(cfg->cmd, UART1_REG(TX));
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}
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static int qnap_power_off_probe(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct resource *res;
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struct clk *clk;
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const struct of_device_id *match =
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of_match_node(qnap_power_off_of_match_table, np);
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cfg = match->data;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "Missing resource");
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return -EINVAL;
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}
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base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
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if (!base) {
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dev_err(&pdev->dev, "Unable to map resource");
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return -EINVAL;
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}
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/* We need to know tclk in order to calculate the UART divisor */
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clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(clk)) {
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dev_err(&pdev->dev, "Clk missing");
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return PTR_ERR(clk);
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}
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tclk = clk_get_rate(clk);
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/* Check that nothing else has already setup a handler */
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if (pm_power_off) {
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dev_err(&pdev->dev, "pm_power_off already claimed for %ps",
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pm_power_off);
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return -EBUSY;
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}
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pm_power_off = qnap_power_off;
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return 0;
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}
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static void qnap_power_off_remove(struct platform_device *pdev)
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{
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pm_power_off = NULL;
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}
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static struct platform_driver qnap_power_off_driver = {
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.probe = qnap_power_off_probe,
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.remove_new = qnap_power_off_remove,
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.driver = {
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.name = "qnap_power_off",
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.of_match_table = of_match_ptr(qnap_power_off_of_match_table),
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},
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};
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module_platform_driver(qnap_power_off_driver);
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MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
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MODULE_DESCRIPTION("QNAP Power off driver");
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MODULE_LICENSE("GPL v2");
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