linux/drivers/power/reset/qnap-poweroff.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

137 lines
3.2 KiB
C

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