From e42c73f1ef0da5970a71f98440193fa9b1e9fb86 Mon Sep 17 00:00:00 2001 From: Andrej Picej Date: Fri, 4 Nov 2022 08:03:56 +0100 Subject: [PATCH] watchdog: imx2_wdg: suspend watchdog in WAIT mode Putting device into the "Suspend-To-Idle" mode causes watchdog to trigger and resets the board after set watchdog timeout period elapses. Introduce new device-tree property "fsl,suspend-in-wait" which suspends watchdog in WAIT mode. This is done by setting WDW bit in WCR (Watchdog Control Register). Watchdog operation is restored after exiting WAIT mode as expected. WAIT mode corresponds with Linux's "Suspend-To-Idle". Signed-off-by: Andrej Picej Reviewed-by: Fabio Estevam Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20221104070358.426657-2-andrej.picej@norik.com Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/imx2_wdt.c | 55 +++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index d0c5d47ddede..19ab7b3d286b 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -35,6 +36,7 @@ #define IMX2_WDT_WCR 0x00 /* Control Register */ #define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */ +#define IMX2_WDT_WCR_WDW BIT(7) /* -> Watchdog disable for WAIT */ #define IMX2_WDT_WCR_WDA BIT(5) /* -> External Reset WDOG_B */ #define IMX2_WDT_WCR_SRS BIT(4) /* -> Software Reset Signal */ #define IMX2_WDT_WCR_WRE BIT(3) /* -> WDOG Reset Enable */ @@ -60,13 +62,19 @@ #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8) +struct imx2_wdt_data { + bool wdw_supported; +}; + struct imx2_wdt_device { struct clk *clk; struct regmap *regmap; struct watchdog_device wdog; + const struct imx2_wdt_data *data; bool ext_reset; bool clk_is_on; bool no_ping; + bool sleep_wait; }; static bool nowayout = WATCHDOG_NOWAYOUT; @@ -129,6 +137,9 @@ static inline void imx2_wdt_setup(struct watchdog_device *wdog) /* Suspend timer in low power mode, write once-only */ val |= IMX2_WDT_WCR_WDZST; + /* Suspend timer in low power WAIT mode, write once-only */ + if (wdev->sleep_wait) + val |= IMX2_WDT_WCR_WDW; /* Strip the old watchdog Time-Out value */ val &= ~IMX2_WDT_WCR_WT; /* Generate internal chip-level reset if WDOG times out */ @@ -292,6 +303,8 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000; wdog->parent = dev; + wdev->data = of_device_get_match_data(dev); + ret = platform_get_irq(pdev, 0); if (ret > 0) if (!devm_request_irq(dev, ret, imx2_wdt_isr, 0, @@ -313,9 +326,18 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) wdev->ext_reset = of_property_read_bool(dev->of_node, "fsl,ext-reset-output"); + + if (of_property_read_bool(dev->of_node, "fsl,suspend-in-wait")) { + if (!wdev->data->wdw_supported) { + dev_err(dev, "suspend-in-wait not supported\n"); + return -EINVAL; + } + wdev->sleep_wait = true; + } + /* * The i.MX7D doesn't support low power mode, so we need to ping the watchdog - * during suspend. + * during suspend. Interaction with "fsl,suspend-in-wait" is unknown! */ wdev->no_ping = !of_device_is_compatible(dev->of_node, "fsl,imx7d-wdt"); platform_set_drvdata(pdev, wdog); @@ -417,9 +439,36 @@ static int __maybe_unused imx2_wdt_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, imx2_wdt_resume); +struct imx2_wdt_data imx_wdt = { + .wdw_supported = true, +}; + +struct imx2_wdt_data imx_wdt_legacy = { + .wdw_supported = false, +}; + static const struct of_device_id imx2_wdt_dt_ids[] = { - { .compatible = "fsl,imx21-wdt", }, - { .compatible = "fsl,imx7d-wdt", }, + { .compatible = "fsl,imx21-wdt", .data = &imx_wdt_legacy }, + { .compatible = "fsl,imx25-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx27-wdt", .data = &imx_wdt_legacy }, + { .compatible = "fsl,imx31-wdt", .data = &imx_wdt_legacy }, + { .compatible = "fsl,imx35-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx50-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx51-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx53-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx6q-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx6sl-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx6sll-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx6sx-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx6ul-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx7d-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx8mm-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx8mn-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx8mp-wdt", .data = &imx_wdt }, + { .compatible = "fsl,imx8mq-wdt", .data = &imx_wdt }, + { .compatible = "fsl,ls1012a-wdt", .data = &imx_wdt_legacy }, + { .compatible = "fsl,ls1043a-wdt", .data = &imx_wdt_legacy }, + { .compatible = "fsl,vf610-wdt", .data = &imx_wdt }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids);