blob: 298089d45ab895086c06c8be6f16824e26889575 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/* Marvell GTI Watchdog driver
*
* Copyright (C) 2023 Marvell.
*/
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/watchdog.h>
/*
* Hardware supports following mode of operation:
* 1) Interrupt Only:
* This will generate the interrupt to arm core whenever timeout happens.
*
* 2) Interrupt + del3t (Interrupt to firmware (SCP processor)).
* This will generate interrupt to arm core on 1st timeout happens
* This will generate interrupt to SCP processor on 2nd timeout happens
*
* 3) Interrupt + Interrupt to SCP processor (called delt3t) + reboot.
* This will generate interrupt to arm core on 1st timeout happens
* Will generate interrupt to SCP processor on 2nd timeout happens,
* if interrupt is configured.
* Reboot on 3rd timeout.
*
* Driver will use hardware in mode-3 above so that system can reboot in case
* a hardware hang. Also h/w is configured not to generate SCP interrupt, so
* effectively 2nd timeout is ignored within hardware.
*
* First timeout is effectively watchdog pretimeout.
*/
/* GTI CWD Watchdog (GTI_CWD_WDOG) Register */
#define GTI_CWD_WDOG(reg_offset) (0x8 * (reg_offset))
#define GTI_CWD_WDOG_MODE_INT_DEL3T_RST 0x3
#define GTI_CWD_WDOG_MODE_MASK GENMASK_ULL(1, 0)
#define GTI_CWD_WDOG_LEN_SHIFT 4
#define GTI_CWD_WDOG_LEN_MASK GENMASK_ULL(19, 4)
#define GTI_CWD_WDOG_CNT_SHIFT 20
#define GTI_CWD_WDOG_CNT_MASK GENMASK_ULL(43, 20)
/* GTI CWD Watchdog Interrupt (GTI_CWD_INT) Register */
#define GTI_CWD_INT 0x200
#define GTI_CWD_INT_PENDING_STATUS(bit) BIT_ULL(bit)
/* GTI CWD Watchdog Interrupt Enable Clear (GTI_CWD_INT_ENA_CLR) Register */
#define GTI_CWD_INT_ENA_CLR 0x210
#define GTI_CWD_INT_ENA_CLR_VAL(bit) BIT_ULL(bit)
/* GTI CWD Watchdog Interrupt Enable Set (GTI_CWD_INT_ENA_SET) Register */
#define GTI_CWD_INT_ENA_SET 0x218
#define GTI_CWD_INT_ENA_SET_VAL(bit) BIT_ULL(bit)
/* GTI CWD Watchdog Poke (GTI_CWD_POKE) Registers */
#define GTI_CWD_POKE(reg_offset) (0x10000 + 0x8 * (reg_offset))
#define GTI_CWD_POKE_VAL 1
struct gti_match_data {
u32 gti_num_timers;
};
static const struct gti_match_data match_data_octeontx2 = {
.gti_num_timers = 54,
};
static const struct gti_match_data match_data_cn10k = {
.gti_num_timers = 64,
};
struct gti_wdt_priv {
struct watchdog_device wdev;
void __iomem *base;
u32 clock_freq;
struct clk *sclk;
/* wdt_timer_idx used for timer to be used for system watchdog */
u32 wdt_timer_idx;
const struct gti_match_data *data;
};
static irqreturn_t gti_wdt_interrupt(int irq, void *data)
{
struct watchdog_device *wdev = data;
struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev);
/* Clear Interrupt Pending Status */
writeq(GTI_CWD_INT_PENDING_STATUS(priv->wdt_timer_idx),
priv->base + GTI_CWD_INT);
watchdog_notify_pretimeout(wdev);
return IRQ_HANDLED;
}
static int gti_wdt_ping(struct watchdog_device *wdev)
{
struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev);
writeq(GTI_CWD_POKE_VAL,
priv->base + GTI_CWD_POKE(priv->wdt_timer_idx));
return 0;
}
static int gti_wdt_start(struct watchdog_device *wdev)
{
struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev);
u64 regval;
if (!wdev->pretimeout)
return -EINVAL;
set_bit(WDOG_HW_RUNNING, &wdev->status);
/* Clear any pending interrupt */
writeq(GTI_CWD_INT_PENDING_STATUS(priv->wdt_timer_idx),
priv->base + GTI_CWD_INT);
/* Enable Interrupt */
writeq(GTI_CWD_INT_ENA_SET_VAL(priv->wdt_timer_idx),
priv->base + GTI_CWD_INT_ENA_SET);
/* Set (Interrupt + SCP interrupt (DEL3T) + core domain reset) Mode */
regval = readq(priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx));
regval |= GTI_CWD_WDOG_MODE_INT_DEL3T_RST;
writeq(regval, priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx));
return 0;
}
static int gti_wdt_stop(struct watchdog_device *wdev)
{
struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev);
u64 regval;
/* Disable Interrupt */
writeq(GTI_CWD_INT_ENA_CLR_VAL(priv->wdt_timer_idx),
priv->base + GTI_CWD_INT_ENA_CLR);
/* Set GTI_CWD_WDOG.Mode = 0 to stop the timer */
regval = readq(priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx));
regval &= ~GTI_CWD_WDOG_MODE_MASK;
writeq(regval, priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx));
return 0;
}
static int gti_wdt_settimeout(struct watchdog_device *wdev,
unsigned int timeout)
{
struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev);
u64 timeout_wdog, regval;
/* Update new timeout */
wdev->timeout = timeout;
/* Pretimeout is 1/3 of timeout */
wdev->pretimeout = timeout / 3;
/* Get clock cycles from pretimeout */
timeout_wdog = (u64)priv->clock_freq * wdev->pretimeout;
/* Watchdog counts in 1024 cycle steps */
timeout_wdog = timeout_wdog >> 10;
/* GTI_CWD_WDOG.CNT: reload counter is 16-bit */
timeout_wdog = (timeout_wdog + 0xff) >> 8;
if (timeout_wdog >= 0x10000)
timeout_wdog = 0xffff;
/*
* GTI_CWD_WDOG.LEN is 24bit, lower 8-bits should be zero and
* upper 16-bits are same as GTI_CWD_WDOG.CNT
*/
regval = readq(priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx));
regval &= GTI_CWD_WDOG_MODE_MASK;
regval |= (timeout_wdog << (GTI_CWD_WDOG_CNT_SHIFT + 8)) |
(timeout_wdog << GTI_CWD_WDOG_LEN_SHIFT);
writeq(regval, priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx));
return 0;
}
static int gti_wdt_set_pretimeout(struct watchdog_device *wdev,
unsigned int timeout)
{
struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev);
struct watchdog_device *wdog_dev = &priv->wdev;
if (!timeout) {
/* Disable Interrupt */
writeq(GTI_CWD_INT_ENA_CLR_VAL(priv->wdt_timer_idx),
priv->base + GTI_CWD_INT_ENA_CLR);
return 0;
}
/* pretimeout should 1/3 of max_timeout */
if (timeout * 3 <= wdog_dev->max_timeout)
return gti_wdt_settimeout(wdev, timeout * 3);
return -EINVAL;
}
static void gti_clk_disable_unprepare(void *data)
{
clk_disable_unprepare(data);
}
static int gti_wdt_get_cntfrq(struct platform_device *pdev,
struct gti_wdt_priv *priv)
{
int err;
priv->sclk = devm_clk_get_enabled(&pdev->dev, NULL);
if (IS_ERR(priv->sclk))
return PTR_ERR(priv->sclk);
err = devm_add_action_or_reset(&pdev->dev,
gti_clk_disable_unprepare, priv->sclk);
if (err)
return err;
priv->clock_freq = clk_get_rate(priv->sclk);
if (!priv->clock_freq)
return -EINVAL;
return 0;
}
static const struct watchdog_info gti_wdt_ident = {
.identity = "Marvell GTI watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_PRETIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE | WDIOF_CARDRESET,
};
static const struct watchdog_ops gti_wdt_ops = {
.owner = THIS_MODULE,
.start = gti_wdt_start,
.stop = gti_wdt_stop,
.ping = gti_wdt_ping,
.set_timeout = gti_wdt_settimeout,
.set_pretimeout = gti_wdt_set_pretimeout,
};
static int gti_wdt_probe(struct platform_device *pdev)
{
struct gti_wdt_priv *priv;
struct device *dev = &pdev->dev;
struct watchdog_device *wdog_dev;
u64 max_pretimeout;
u32 wdt_idx;
int irq;
int err;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return dev_err_probe(&pdev->dev, PTR_ERR(priv->base),
"reg property not valid/found\n");
err = gti_wdt_get_cntfrq(pdev, priv);
if (err)
return dev_err_probe(&pdev->dev, err,
"GTI clock frequency not valid/found");
priv->data = of_device_get_match_data(dev);
/* default use last timer for watchdog */
priv->wdt_timer_idx = priv->data->gti_num_timers - 1;
err = of_property_read_u32(dev->of_node, "marvell,wdt-timer-index",
&wdt_idx);
if (!err) {
if (wdt_idx >= priv->data->gti_num_timers)
return dev_err_probe(&pdev->dev, -EINVAL,
"GTI wdog timer index not valid");
priv->wdt_timer_idx = wdt_idx;
}
wdog_dev = &priv->wdev;
wdog_dev->info = &gti_wdt_ident;
wdog_dev->ops = &gti_wdt_ops;
wdog_dev->parent = dev;
/*
* Watchdog counter is 24 bit where lower 8 bits are zeros
* This counter decrements every 1024 clock cycles.
*/
max_pretimeout = (GTI_CWD_WDOG_CNT_MASK >> GTI_CWD_WDOG_CNT_SHIFT);
max_pretimeout &= ~0xFFUL;
max_pretimeout = (max_pretimeout * 1024) / priv->clock_freq;
wdog_dev->pretimeout = max_pretimeout;
/* Maximum timeout is 3 times the pretimeout */
wdog_dev->max_timeout = max_pretimeout * 3;
wdog_dev->max_hw_heartbeat_ms = max_pretimeout * 1000;
/* Minimum first timeout (pretimeout) is 1, so min_timeout as 3 */
wdog_dev->min_timeout = 3;
wdog_dev->timeout = wdog_dev->pretimeout;
watchdog_set_drvdata(wdog_dev, priv);
platform_set_drvdata(pdev, priv);
gti_wdt_settimeout(wdog_dev, wdog_dev->timeout);
watchdog_stop_on_reboot(wdog_dev);
watchdog_stop_on_unregister(wdog_dev);
err = devm_watchdog_register_device(dev, wdog_dev);
if (err)
return err;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
err = devm_request_irq(dev, irq, gti_wdt_interrupt, 0,
pdev->name, &priv->wdev);
if (err)
return dev_err_probe(dev, err, "Failed to register interrupt handler\n");
dev_info(dev, "Watchdog enabled (timeout=%d sec)\n", wdog_dev->timeout);
return 0;
}
static const struct of_device_id gti_wdt_of_match[] = {
{ .compatible = "marvell,cn9670-wdt", .data = &match_data_octeontx2},
{ .compatible = "marvell,cn10624-wdt", .data = &match_data_cn10k},
{ },
};
MODULE_DEVICE_TABLE(of, gti_wdt_of_match);
static struct platform_driver gti_wdt_driver = {
.driver = {
.name = "gti-wdt",
.of_match_table = gti_wdt_of_match,
},
.probe = gti_wdt_probe,
};
module_platform_driver(gti_wdt_driver);
MODULE_AUTHOR("Bharat Bhushan <bbhushan2@marvell.com>");
MODULE_DESCRIPTION("Marvell GTI watchdog driver");
MODULE_LICENSE("GPL");