linux/drivers/watchdog/of_xilinx_wdt.c
Rob Herring cc85f87a77 watchdog: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it was merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230726233302.3812749-1-robh@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2023-08-13 14:29:49 +02:00

298 lines
7.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Watchdog Device Driver for Xilinx axi/xps_timebase_wdt
*
* (C) Copyright 2013 - 2014 Xilinx, Inc.
* (C) Copyright 2011 (Alejandro Cabrera <aldaya@gmail.com>)
*/
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/of.h>
/* Register offsets for the Wdt device */
#define XWT_TWCSR0_OFFSET 0x0 /* Control/Status Register0 */
#define XWT_TWCSR1_OFFSET 0x4 /* Control/Status Register1 */
#define XWT_TBR_OFFSET 0x8 /* Timebase Register Offset */
/* Control/Status Register Masks */
#define XWT_CSR0_WRS_MASK BIT(3) /* Reset status */
#define XWT_CSR0_WDS_MASK BIT(2) /* Timer state */
#define XWT_CSR0_EWDT1_MASK BIT(1) /* Enable bit 1 */
/* Control/Status Register 0/1 bits */
#define XWT_CSRX_EWDT2_MASK BIT(0) /* Enable bit 2 */
/* SelfTest constants */
#define XWT_MAX_SELFTEST_LOOP_COUNT 0x00010000
#define XWT_TIMER_FAILED 0xFFFFFFFF
#define WATCHDOG_NAME "Xilinx Watchdog"
struct xwdt_device {
void __iomem *base;
u32 wdt_interval;
spinlock_t spinlock; /* spinlock for register handling */
struct watchdog_device xilinx_wdt_wdd;
struct clk *clk;
};
static int xilinx_wdt_start(struct watchdog_device *wdd)
{
int ret;
u32 control_status_reg;
struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
ret = clk_enable(xdev->clk);
if (ret) {
dev_err(wdd->parent, "Failed to enable clock\n");
return ret;
}
spin_lock(&xdev->spinlock);
/* Clean previous status and enable the watchdog timer */
control_status_reg = ioread32(xdev->base + XWT_TWCSR0_OFFSET);
control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);
iowrite32((control_status_reg | XWT_CSR0_EWDT1_MASK),
xdev->base + XWT_TWCSR0_OFFSET);
iowrite32(XWT_CSRX_EWDT2_MASK, xdev->base + XWT_TWCSR1_OFFSET);
spin_unlock(&xdev->spinlock);
dev_dbg(wdd->parent, "Watchdog Started!\n");
return 0;
}
static int xilinx_wdt_stop(struct watchdog_device *wdd)
{
u32 control_status_reg;
struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
spin_lock(&xdev->spinlock);
control_status_reg = ioread32(xdev->base + XWT_TWCSR0_OFFSET);
iowrite32((control_status_reg & ~XWT_CSR0_EWDT1_MASK),
xdev->base + XWT_TWCSR0_OFFSET);
iowrite32(0, xdev->base + XWT_TWCSR1_OFFSET);
spin_unlock(&xdev->spinlock);
clk_disable(xdev->clk);
dev_dbg(wdd->parent, "Watchdog Stopped!\n");
return 0;
}
static int xilinx_wdt_keepalive(struct watchdog_device *wdd)
{
u32 control_status_reg;
struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
spin_lock(&xdev->spinlock);
control_status_reg = ioread32(xdev->base + XWT_TWCSR0_OFFSET);
control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);
iowrite32(control_status_reg, xdev->base + XWT_TWCSR0_OFFSET);
spin_unlock(&xdev->spinlock);
return 0;
}
static const struct watchdog_info xilinx_wdt_ident = {
.options = WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = WATCHDOG_NAME,
};
static const struct watchdog_ops xilinx_wdt_ops = {
.owner = THIS_MODULE,
.start = xilinx_wdt_start,
.stop = xilinx_wdt_stop,
.ping = xilinx_wdt_keepalive,
};
static u32 xwdt_selftest(struct xwdt_device *xdev)
{
int i;
u32 timer_value1;
u32 timer_value2;
spin_lock(&xdev->spinlock);
timer_value1 = ioread32(xdev->base + XWT_TBR_OFFSET);
timer_value2 = ioread32(xdev->base + XWT_TBR_OFFSET);
for (i = 0;
((i <= XWT_MAX_SELFTEST_LOOP_COUNT) &&
(timer_value2 == timer_value1)); i++) {
timer_value2 = ioread32(xdev->base + XWT_TBR_OFFSET);
}
spin_unlock(&xdev->spinlock);
if (timer_value2 != timer_value1)
return ~XWT_TIMER_FAILED;
else
return XWT_TIMER_FAILED;
}
static int xwdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int rc;
u32 pfreq = 0, enable_once = 0;
struct xwdt_device *xdev;
struct watchdog_device *xilinx_wdt_wdd;
xdev = devm_kzalloc(dev, sizeof(*xdev), GFP_KERNEL);
if (!xdev)
return -ENOMEM;
xilinx_wdt_wdd = &xdev->xilinx_wdt_wdd;
xilinx_wdt_wdd->info = &xilinx_wdt_ident;
xilinx_wdt_wdd->ops = &xilinx_wdt_ops;
xilinx_wdt_wdd->parent = dev;
xdev->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(xdev->base))
return PTR_ERR(xdev->base);
rc = of_property_read_u32(dev->of_node, "xlnx,wdt-interval",
&xdev->wdt_interval);
if (rc)
dev_warn(dev, "Parameter \"xlnx,wdt-interval\" not found\n");
rc = of_property_read_u32(dev->of_node, "xlnx,wdt-enable-once",
&enable_once);
if (rc)
dev_warn(dev,
"Parameter \"xlnx,wdt-enable-once\" not found\n");
watchdog_set_nowayout(xilinx_wdt_wdd, enable_once);
xdev->clk = devm_clk_get_enabled(dev, NULL);
if (IS_ERR(xdev->clk)) {
if (PTR_ERR(xdev->clk) != -ENOENT)
return PTR_ERR(xdev->clk);
/*
* Clock framework support is optional, continue on
* anyways if we don't find a matching clock.
*/
xdev->clk = NULL;
rc = of_property_read_u32(dev->of_node, "clock-frequency",
&pfreq);
if (rc)
dev_warn(dev,
"The watchdog clock freq cannot be obtained\n");
} else {
pfreq = clk_get_rate(xdev->clk);
}
/*
* Twice of the 2^wdt_interval / freq because the first wdt overflow is
* ignored (interrupt), reset is only generated at second wdt overflow
*/
if (pfreq && xdev->wdt_interval)
xilinx_wdt_wdd->timeout = 2 * ((1 << xdev->wdt_interval) /
pfreq);
spin_lock_init(&xdev->spinlock);
watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
rc = xwdt_selftest(xdev);
if (rc == XWT_TIMER_FAILED) {
dev_err(dev, "SelfTest routine error\n");
return rc;
}
rc = devm_watchdog_register_device(dev, xilinx_wdt_wdd);
if (rc)
return rc;
clk_disable(xdev->clk);
dev_info(dev, "Xilinx Watchdog Timer with timeout %ds\n",
xilinx_wdt_wdd->timeout);
platform_set_drvdata(pdev, xdev);
return 0;
}
/**
* xwdt_suspend - Suspend the device.
*
* @dev: handle to the device structure.
* Return: 0 always.
*/
static int __maybe_unused xwdt_suspend(struct device *dev)
{
struct xwdt_device *xdev = dev_get_drvdata(dev);
if (watchdog_active(&xdev->xilinx_wdt_wdd))
xilinx_wdt_stop(&xdev->xilinx_wdt_wdd);
return 0;
}
/**
* xwdt_resume - Resume the device.
*
* @dev: handle to the device structure.
* Return: 0 on success, errno otherwise.
*/
static int __maybe_unused xwdt_resume(struct device *dev)
{
struct xwdt_device *xdev = dev_get_drvdata(dev);
int ret = 0;
if (watchdog_active(&xdev->xilinx_wdt_wdd))
ret = xilinx_wdt_start(&xdev->xilinx_wdt_wdd);
return ret;
}
static SIMPLE_DEV_PM_OPS(xwdt_pm_ops, xwdt_suspend, xwdt_resume);
/* Match table for of_platform binding */
static const struct of_device_id xwdt_of_match[] = {
{ .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
{ .compatible = "xlnx,xps-timebase-wdt-1.01.a", },
{},
};
MODULE_DEVICE_TABLE(of, xwdt_of_match);
static struct platform_driver xwdt_driver = {
.probe = xwdt_probe,
.driver = {
.name = WATCHDOG_NAME,
.of_match_table = xwdt_of_match,
.pm = &xwdt_pm_ops,
},
};
module_platform_driver(xwdt_driver);
MODULE_AUTHOR("Alejandro Cabrera <aldaya@gmail.com>");
MODULE_DESCRIPTION("Xilinx Watchdog driver");
MODULE_LICENSE("GPL");