linux/drivers/watchdog/lantiq_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

290 lines
7.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (C) 2010 John Crispin <john@phrozen.org>
* Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
* Based on EP93xx wdt driver
*/
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/watchdog.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <lantiq_soc.h>
#define LTQ_XRX_RCU_RST_STAT 0x0014
#define LTQ_XRX_RCU_RST_STAT_WDT BIT(31)
/* CPU0 Reset Source Register */
#define LTQ_FALCON_SYS1_CPU0RS 0x0060
/* reset cause mask */
#define LTQ_FALCON_SYS1_CPU0RS_MASK 0x0007
#define LTQ_FALCON_SYS1_CPU0RS_WDT 0x02
/*
* Section 3.4 of the datasheet
* The password sequence protects the WDT control register from unintended
* write actions, which might cause malfunction of the WDT.
*
* essentially the following two magic passwords need to be written to allow
* IO access to the WDT core
*/
#define LTQ_WDT_CR_PW1 0x00BE0000
#define LTQ_WDT_CR_PW2 0x00DC0000
#define LTQ_WDT_CR 0x0 /* watchdog control register */
#define LTQ_WDT_CR_GEN BIT(31) /* enable bit */
/* Pre-warning limit set to 1/16 of max WDT period */
#define LTQ_WDT_CR_PWL (0x3 << 26)
/* set clock divider to 0x40000 */
#define LTQ_WDT_CR_CLKDIV (0x3 << 24)
#define LTQ_WDT_CR_PW_MASK GENMASK(23, 16) /* Password field */
#define LTQ_WDT_CR_MAX_TIMEOUT ((1 << 16) - 1) /* The reload field is 16 bit */
#define LTQ_WDT_SR 0x8 /* watchdog status register */
#define LTQ_WDT_SR_EN BIT(31) /* Enable */
#define LTQ_WDT_SR_VALUE_MASK GENMASK(15, 0) /* Timer value */
#define LTQ_WDT_DIVIDER 0x40000
static bool nowayout = WATCHDOG_NOWAYOUT;
struct ltq_wdt_hw {
int (*bootstatus_get)(struct device *dev);
};
struct ltq_wdt_priv {
struct watchdog_device wdt;
void __iomem *membase;
unsigned long clk_rate;
};
static u32 ltq_wdt_r32(struct ltq_wdt_priv *priv, u32 offset)
{
return __raw_readl(priv->membase + offset);
}
static void ltq_wdt_w32(struct ltq_wdt_priv *priv, u32 val, u32 offset)
{
__raw_writel(val, priv->membase + offset);
}
static void ltq_wdt_mask(struct ltq_wdt_priv *priv, u32 clear, u32 set,
u32 offset)
{
u32 val = ltq_wdt_r32(priv, offset);
val &= ~(clear);
val |= set;
ltq_wdt_w32(priv, val, offset);
}
static struct ltq_wdt_priv *ltq_wdt_get_priv(struct watchdog_device *wdt)
{
return container_of(wdt, struct ltq_wdt_priv, wdt);
}
static struct watchdog_info ltq_wdt_info = {
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_CARDRESET,
.identity = "ltq_wdt",
};
static int ltq_wdt_start(struct watchdog_device *wdt)
{
struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
u32 timeout;
timeout = wdt->timeout * priv->clk_rate;
ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
/* write the second magic plus the configuration and new timeout */
ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK | LTQ_WDT_CR_MAX_TIMEOUT,
LTQ_WDT_CR_GEN | LTQ_WDT_CR_PWL | LTQ_WDT_CR_CLKDIV |
LTQ_WDT_CR_PW2 | timeout,
LTQ_WDT_CR);
return 0;
}
static int ltq_wdt_stop(struct watchdog_device *wdt)
{
struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
ltq_wdt_mask(priv, LTQ_WDT_CR_GEN | LTQ_WDT_CR_PW_MASK,
LTQ_WDT_CR_PW2, LTQ_WDT_CR);
return 0;
}
static int ltq_wdt_ping(struct watchdog_device *wdt)
{
struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
u32 timeout;
timeout = wdt->timeout * priv->clk_rate;
ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
/* write the second magic plus the configuration and new timeout */
ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK | LTQ_WDT_CR_MAX_TIMEOUT,
LTQ_WDT_CR_PW2 | timeout, LTQ_WDT_CR);
return 0;
}
static unsigned int ltq_wdt_get_timeleft(struct watchdog_device *wdt)
{
struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
u64 timeout;
timeout = ltq_wdt_r32(priv, LTQ_WDT_SR) & LTQ_WDT_SR_VALUE_MASK;
return do_div(timeout, priv->clk_rate);
}
static const struct watchdog_ops ltq_wdt_ops = {
.owner = THIS_MODULE,
.start = ltq_wdt_start,
.stop = ltq_wdt_stop,
.ping = ltq_wdt_ping,
.get_timeleft = ltq_wdt_get_timeleft,
};
static int ltq_wdt_xrx_bootstatus_get(struct device *dev)
{
struct regmap *rcu_regmap;
u32 val;
int err;
rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
if (IS_ERR(rcu_regmap))
return PTR_ERR(rcu_regmap);
err = regmap_read(rcu_regmap, LTQ_XRX_RCU_RST_STAT, &val);
if (err)
return err;
if (val & LTQ_XRX_RCU_RST_STAT_WDT)
return WDIOF_CARDRESET;
return 0;
}
static int ltq_wdt_falcon_bootstatus_get(struct device *dev)
{
struct regmap *rcu_regmap;
u32 val;
int err;
rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
"lantiq,rcu");
if (IS_ERR(rcu_regmap))
return PTR_ERR(rcu_regmap);
err = regmap_read(rcu_regmap, LTQ_FALCON_SYS1_CPU0RS, &val);
if (err)
return err;
if ((val & LTQ_FALCON_SYS1_CPU0RS_MASK) == LTQ_FALCON_SYS1_CPU0RS_WDT)
return WDIOF_CARDRESET;
return 0;
}
static int ltq_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ltq_wdt_priv *priv;
struct watchdog_device *wdt;
struct clk *clk;
const struct ltq_wdt_hw *ltq_wdt_hw;
int ret;
u32 status;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->membase = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->membase))
return PTR_ERR(priv->membase);
/* we do not need to enable the clock as it is always running */
clk = clk_get_io();
priv->clk_rate = clk_get_rate(clk) / LTQ_WDT_DIVIDER;
if (!priv->clk_rate) {
dev_err(dev, "clock rate less than divider %i\n",
LTQ_WDT_DIVIDER);
return -EINVAL;
}
wdt = &priv->wdt;
wdt->info = &ltq_wdt_info;
wdt->ops = &ltq_wdt_ops;
wdt->min_timeout = 1;
wdt->max_timeout = LTQ_WDT_CR_MAX_TIMEOUT / priv->clk_rate;
wdt->timeout = wdt->max_timeout;
wdt->parent = dev;
ltq_wdt_hw = of_device_get_match_data(dev);
if (ltq_wdt_hw && ltq_wdt_hw->bootstatus_get) {
ret = ltq_wdt_hw->bootstatus_get(dev);
if (ret >= 0)
wdt->bootstatus = ret;
}
watchdog_set_nowayout(wdt, nowayout);
watchdog_init_timeout(wdt, 0, dev);
status = ltq_wdt_r32(priv, LTQ_WDT_SR);
if (status & LTQ_WDT_SR_EN) {
/*
* If the watchdog is already running overwrite it with our
* new settings. Stop is not needed as the start call will
* replace all settings anyway.
*/
ltq_wdt_start(wdt);
set_bit(WDOG_HW_RUNNING, &wdt->status);
}
return devm_watchdog_register_device(dev, wdt);
}
static const struct ltq_wdt_hw ltq_wdt_xrx100 = {
.bootstatus_get = ltq_wdt_xrx_bootstatus_get,
};
static const struct ltq_wdt_hw ltq_wdt_falcon = {
.bootstatus_get = ltq_wdt_falcon_bootstatus_get,
};
static const struct of_device_id ltq_wdt_match[] = {
{ .compatible = "lantiq,wdt", .data = NULL },
{ .compatible = "lantiq,xrx100-wdt", .data = &ltq_wdt_xrx100 },
{ .compatible = "lantiq,falcon-wdt", .data = &ltq_wdt_falcon },
{},
};
MODULE_DEVICE_TABLE(of, ltq_wdt_match);
static struct platform_driver ltq_wdt_driver = {
.probe = ltq_wdt_probe,
.driver = {
.name = "wdt",
.of_match_table = ltq_wdt_match,
},
};
module_platform_driver(ltq_wdt_driver);
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_AUTHOR("John Crispin <john@phrozen.org>");
MODULE_DESCRIPTION("Lantiq SoC Watchdog");
MODULE_LICENSE("GPL");