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SubjectRe: [PATCH 2/2 v8] Watchdog: Add marvell GTI watchdog driver
On 5/25/23 23:26, Bharat Bhushan wrote:
> This patch add support for Marvell GTI watchdog. Global timer
> unit (GTI) support hardware watchdog timer. Software programs
> watchdog timer to generate interrupt on first timeout, second
> timeout is configured to be ignored and system reboots on
> third timeout.
>
> Signed-off-by: Bharat Bhushan <bbhushan2@marvell.com>
> ---
> v8:
> - Compatible names as per soc names
> - This driver run on ARM64 based architecture, Added 64BIT config
> dependency to avoid compilation error related to readq/writeq on
> 32 as platform (Hexagon)
>

In the future, please provide complete change logs.

> drivers/watchdog/Kconfig | 13 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/marvell_gti_wdt.c | 346 +++++++++++++++++++++++++++++
> 3 files changed, 360 insertions(+)
> create mode 100644 drivers/watchdog/marvell_gti_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index f22138709bf5..bbdc20f33dbf 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1779,6 +1779,19 @@ config OCTEON_WDT
> from the first interrupt, it is then only poked when the
> device is written.
>
> +config MARVELL_GTI_WDT
> + tristate "Marvell GTI Watchdog driver"
> + depends on ARCH_THUNDER || (COMPILE_TEST && 64BIT)
> + default y

Does this watchdog exist on all Thunder processors ?
If not please drop.

> + select WATCHDOG_CORE
> + help
> + Marvell GTI hardware supports watchdog timer. First timeout
> + works as watchdog pretimeout and installed interrupt handler
> + will be called on first timeout. Hardware can generate interrupt
> + to SCP on second timeout but it is not enabled, So second
> + timeout is ignored. If device poke does not happen then system
> + will reboot on third timeout.
> +
> config BCM2835_WDT
> tristate "Broadcom BCM2835 hardware watchdog"
> depends on ARCH_BCM2835 || (OF && COMPILE_TEST)
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index b4c4ccf2d703..a164cd161ef3 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -98,6 +98,7 @@ obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o
> obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o
> obj-$(CONFIG_APPLE_WATCHDOG) += apple_wdt.o
> obj-$(CONFIG_SUNPLUS_WATCHDOG) += sunplus_wdt.o
> +obj-$(CONFIG_MARVELL_GTI_WDT) += marvell_gti_wdt.o
>
> # X86 (i386 + ia64 + x86_64) Architecture
> obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
> diff --git a/drivers/watchdog/marvell_gti_wdt.c b/drivers/watchdog/marvell_gti_wdt.c
> new file mode 100644
> index 000000000000..976bb9306115
> --- /dev/null
> +++ b/drivers/watchdog/marvell_gti_wdt.c
> @@ -0,0 +1,346 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Marvell GTI Watchdog driver
> + *
> + * Copyright (C) 2023 Marvell.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/watchdog.h>
> +#include <linux/clk.h>
> +
Alphabetic order, please. Also, include io.h since
you are using io functions (writeq).

> +/*
> + * 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)

reg_offset in ()

> +#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) (1 << 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) (1 << bit)

Please use 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) (1 << 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 = {

The driver depends on ARCH_THUNDER but not ARCH_THUNDER2.

> + .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;
> +
> + /* 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(&pdev->dev, NULL);
> + if (IS_ERR(priv->sclk))
> + return PTR_ERR(priv->sclk);
> +
> + err = clk_prepare_enable(priv->sclk);
> + if (err)
> + return err;
> +

Any reason for not using devm_clk_get_enabled() ?

> + 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, err,
> + "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;
> + /* 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 dev_err_probe(&pdev->dev, irq, "IRQ resource not found\n");
> +
> + 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,cn9880-wdt", .data = &match_data_octeontx2},
> + { .compatible = "marvell,cnf9535-wdt", .data = &match_data_octeontx2},
> + { .compatible = "marvell,cn10624-wdt", .data = &match_data_cn10k},
> + { .compatible = "marvell,cn10308-wdt", .data = &match_data_cn10k},
> + { .compatible = "marvell,cnf10518-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");

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