diff options
Diffstat (limited to 'drivers/watchdog/xilinx_wwdt.c')
| -rw-r--r-- | drivers/watchdog/xilinx_wwdt.c | 75 |
1 files changed, 63 insertions, 12 deletions
diff --git a/drivers/watchdog/xilinx_wwdt.c b/drivers/watchdog/xilinx_wwdt.c index d271e2e8d6e2..3d2a156f7180 100644 --- a/drivers/watchdog/xilinx_wwdt.c +++ b/drivers/watchdog/xilinx_wwdt.c @@ -2,7 +2,7 @@ /* * Window watchdog device driver for Xilinx Versal WWDT * - * Copyright (C) 2022 - 2023, Advanced Micro Devices, Inc. + * Copyright (C) 2022 - 2024, Advanced Micro Devices, Inc. */ #include <linux/clk.h> @@ -36,6 +36,12 @@ #define XWWDT_CLOSE_WINDOW_PERCENT 50 +/* Maximum count value of each 32 bit window */ +#define XWWDT_MAX_COUNT_WINDOW GENMASK(31, 0) + +/* Maximum count value of closed and open window combined */ +#define XWWDT_MAX_COUNT_WINDOW_COMBINED GENMASK_ULL(32, 1) + static int wwdt_timeout; static int closed_window_percent; @@ -54,6 +60,8 @@ MODULE_PARM_DESC(closed_window_percent, * @xilinx_wwdt_wdd: watchdog device structure * @freq: source clock frequency of WWDT * @close_percent: Closed window percent + * @closed_timeout: Closed window timeout in ticks + * @open_timeout: Open window timeout in ticks */ struct xwwdt_device { void __iomem *base; @@ -61,27 +69,22 @@ struct xwwdt_device { struct watchdog_device xilinx_wwdt_wdd; unsigned long freq; u32 close_percent; + u64 closed_timeout; + u64 open_timeout; }; static int xilinx_wwdt_start(struct watchdog_device *wdd) { struct xwwdt_device *xdev = watchdog_get_drvdata(wdd); struct watchdog_device *xilinx_wwdt_wdd = &xdev->xilinx_wwdt_wdd; - u64 time_out, closed_timeout, open_timeout; u32 control_status_reg; - /* Calculate timeout count */ - time_out = xdev->freq * wdd->timeout; - closed_timeout = div_u64(time_out * xdev->close_percent, 100); - open_timeout = time_out - closed_timeout; - wdd->min_hw_heartbeat_ms = xdev->close_percent * 10 * wdd->timeout; - spin_lock(&xdev->spinlock); iowrite32(XWWDT_MWR_MASK, xdev->base + XWWDT_MWR_OFFSET); iowrite32(~(u32)XWWDT_ESR_WEN_MASK, xdev->base + XWWDT_ESR_OFFSET); - iowrite32((u32)closed_timeout, xdev->base + XWWDT_FWR_OFFSET); - iowrite32((u32)open_timeout, xdev->base + XWWDT_SWR_OFFSET); + iowrite32((u32)xdev->closed_timeout, xdev->base + XWWDT_FWR_OFFSET); + iowrite32((u32)xdev->open_timeout, xdev->base + XWWDT_SWR_OFFSET); /* Enable the window watchdog timer */ control_status_reg = ioread32(xdev->base + XWWDT_ESR_OFFSET); @@ -133,7 +136,12 @@ static int xwwdt_probe(struct platform_device *pdev) struct watchdog_device *xilinx_wwdt_wdd; struct device *dev = &pdev->dev; struct xwwdt_device *xdev; + u64 max_per_window_ms; + u64 min_per_window_ms; + u64 timeout_count; struct clk *clk; + u32 timeout_ms; + u64 ms_count; int ret; xdev = devm_kzalloc(dev, sizeof(*xdev), GFP_KERNEL); @@ -154,12 +162,13 @@ static int xwwdt_probe(struct platform_device *pdev) return PTR_ERR(clk); xdev->freq = clk_get_rate(clk); - if (!xdev->freq) + if (xdev->freq < 1000000) return -EINVAL; xilinx_wwdt_wdd->min_timeout = XWWDT_MIN_TIMEOUT; xilinx_wwdt_wdd->timeout = XWWDT_DEFAULT_TIMEOUT; - xilinx_wwdt_wdd->max_hw_heartbeat_ms = 1000 * xilinx_wwdt_wdd->timeout; + xilinx_wwdt_wdd->max_hw_heartbeat_ms = + div64_u64(XWWDT_MAX_COUNT_WINDOW_COMBINED, xdev->freq) * 1000; if (closed_window_percent == 0 || closed_window_percent >= 100) xdev->close_percent = XWWDT_CLOSE_WINDOW_PERCENT; @@ -167,6 +176,48 @@ static int xwwdt_probe(struct platform_device *pdev) xdev->close_percent = closed_window_percent; watchdog_init_timeout(xilinx_wwdt_wdd, wwdt_timeout, &pdev->dev); + + /* Calculate ticks for 1 milli-second */ + ms_count = div_u64(xdev->freq, 1000); + timeout_ms = xilinx_wwdt_wdd->timeout * 1000; + timeout_count = timeout_ms * ms_count; + + if (timeout_ms > xilinx_wwdt_wdd->max_hw_heartbeat_ms) { + /* + * To avoid ping restrictions until the minimum hardware heartbeat, + * we will solely rely on the open window and + * adjust the minimum hardware heartbeat to 0. + */ + xdev->closed_timeout = 0; + xdev->open_timeout = XWWDT_MAX_COUNT_WINDOW; + xilinx_wwdt_wdd->min_hw_heartbeat_ms = 0; + xilinx_wwdt_wdd->max_hw_heartbeat_ms = xilinx_wwdt_wdd->max_hw_heartbeat_ms / 2; + } else { + xdev->closed_timeout = div64_u64(timeout_count * xdev->close_percent, 100); + xilinx_wwdt_wdd->min_hw_heartbeat_ms = + div64_u64(timeout_ms * xdev->close_percent, 100); + + if (timeout_ms > xilinx_wwdt_wdd->max_hw_heartbeat_ms / 2) { + max_per_window_ms = xilinx_wwdt_wdd->max_hw_heartbeat_ms / 2; + min_per_window_ms = timeout_ms - max_per_window_ms; + + if (xilinx_wwdt_wdd->min_hw_heartbeat_ms > max_per_window_ms) { + dev_info(xilinx_wwdt_wdd->parent, + "Closed window cannot be set to %d%%. Using maximum supported value.\n", + xdev->close_percent); + xdev->closed_timeout = max_per_window_ms * ms_count; + xilinx_wwdt_wdd->min_hw_heartbeat_ms = max_per_window_ms; + } else if (xilinx_wwdt_wdd->min_hw_heartbeat_ms < min_per_window_ms) { + dev_info(xilinx_wwdt_wdd->parent, + "Closed window cannot be set to %d%%. Using minimum supported value.\n", + xdev->close_percent); + xdev->closed_timeout = min_per_window_ms * ms_count; + xilinx_wwdt_wdd->min_hw_heartbeat_ms = min_per_window_ms; + } + } + xdev->open_timeout = timeout_count - xdev->closed_timeout; + } + spin_lock_init(&xdev->spinlock); watchdog_set_drvdata(xilinx_wwdt_wdd, xdev); watchdog_set_nowayout(xilinx_wwdt_wdd, 1); |