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Jetpack/kernel/kernel-4.9/drivers/watchdog/meson_gxbb_wdt.c

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/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* Copyright (c) 2016 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
* The full GNU General Public License is included in this distribution
* in the file called COPYING.
*
* BSD LICENSE
*
* Copyright (c) 2016 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define DEFAULT_TIMEOUT 30 /* seconds */
#define GXBB_WDT_CTRL_REG 0x0
#define GXBB_WDT_TCNT_REG 0x8
#define GXBB_WDT_RSET_REG 0xc
#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
#define GXBB_WDT_CTRL_CLK_EN BIT(24)
#define GXBB_WDT_CTRL_EE_RESET BIT(21)
#define GXBB_WDT_CTRL_EN BIT(18)
#define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1)
#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1)
#define GXBB_WDT_TCNT_CNT_SHIFT 16
struct meson_gxbb_wdt {
void __iomem *reg_base;
struct watchdog_device wdt_dev;
struct clk *clk;
};
static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
data->reg_base + GXBB_WDT_CTRL_REG);
return 0;
}
static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
data->reg_base + GXBB_WDT_CTRL_REG);
return 0;
}
static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
writel(0, data->reg_base + GXBB_WDT_RSET_REG);
return 0;
}
static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
unsigned long tcnt = timeout * 1000;
if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
tcnt = GXBB_WDT_TCNT_SETUP_MASK;
wdt_dev->timeout = timeout;
meson_gxbb_wdt_ping(wdt_dev);
writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);
return 0;
}
static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
{
struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
unsigned long reg;
reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) -
(reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
}
static const struct watchdog_ops meson_gxbb_wdt_ops = {
.start = meson_gxbb_wdt_start,
.stop = meson_gxbb_wdt_stop,
.ping = meson_gxbb_wdt_ping,
.set_timeout = meson_gxbb_wdt_set_timeout,
.get_timeleft = meson_gxbb_wdt_get_timeleft,
};
static const struct watchdog_info meson_gxbb_wdt_info = {
.identity = "Meson GXBB Watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
{
struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
if (watchdog_active(&data->wdt_dev))
meson_gxbb_wdt_start(&data->wdt_dev);
return 0;
}
static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
{
struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
if (watchdog_active(&data->wdt_dev))
meson_gxbb_wdt_stop(&data->wdt_dev);
return 0;
}
static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
};
static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
{ .compatible = "amlogic,meson-gxbb-wdt", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
static int meson_gxbb_wdt_probe(struct platform_device *pdev)
{
struct meson_gxbb_wdt *data;
struct resource *res;
int ret;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->reg_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->reg_base))
return PTR_ERR(data->reg_base);
data->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(data->clk))
return PTR_ERR(data->clk);
clk_prepare_enable(data->clk);
platform_set_drvdata(pdev, data);
data->wdt_dev.parent = &pdev->dev;
data->wdt_dev.info = &meson_gxbb_wdt_info;
data->wdt_dev.ops = &meson_gxbb_wdt_ops;
data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
data->wdt_dev.min_timeout = 1;
data->wdt_dev.timeout = DEFAULT_TIMEOUT;
watchdog_set_drvdata(&data->wdt_dev, data);
/* Setup with 1ms timebase */
writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
GXBB_WDT_CTRL_EE_RESET |
GXBB_WDT_CTRL_CLK_EN |
GXBB_WDT_CTRL_CLKDIV_EN,
data->reg_base + GXBB_WDT_CTRL_REG);
meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
ret = watchdog_register_device(&data->wdt_dev);
if (ret) {
clk_disable_unprepare(data->clk);
return ret;
}
return 0;
}
static int meson_gxbb_wdt_remove(struct platform_device *pdev)
{
struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
watchdog_unregister_device(&data->wdt_dev);
clk_disable_unprepare(data->clk);
return 0;
}
static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
{
struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
meson_gxbb_wdt_stop(&data->wdt_dev);
}
static struct platform_driver meson_gxbb_wdt_driver = {
.probe = meson_gxbb_wdt_probe,
.remove = meson_gxbb_wdt_remove,
.shutdown = meson_gxbb_wdt_shutdown,
.driver = {
.name = "meson-gxbb-wdt",
.pm = &meson_gxbb_wdt_pm_ops,
.of_match_table = meson_gxbb_wdt_dt_ids,
},
};
module_platform_driver(meson_gxbb_wdt_driver);
MODULE_ALIAS("platform:meson-gxbb-wdt");
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
MODULE_LICENSE("Dual BSD/GPL");
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