/* * PIC32 watchdog driver * * Joshua Henderson * Copyright (c) 2016, Microchip Technology Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include #include /* Watchdog Timer Registers */ #define WDTCON_REG 0x00 /* Watchdog Timer Control Register fields */ #define WDTCON_WIN_EN BIT(0) #define WDTCON_RMCS_MASK 0x0003 #define WDTCON_RMCS_SHIFT 0x0006 #define WDTCON_RMPS_MASK 0x001F #define WDTCON_RMPS_SHIFT 0x0008 #define WDTCON_ON BIT(15) #define WDTCON_CLR_KEY 0x5743 /* Reset Control Register fields for watchdog */ #define RESETCON_TIMEOUT_IDLE BIT(2) #define RESETCON_TIMEOUT_SLEEP BIT(3) #define RESETCON_WDT_TIMEOUT BIT(4) struct pic32_wdt { void __iomem *regs; void __iomem *rst_base; struct clk *clk; }; static inline bool pic32_wdt_is_win_enabled(struct pic32_wdt *wdt) { return !!(readl(wdt->regs + WDTCON_REG) & WDTCON_WIN_EN); } static inline u32 pic32_wdt_get_post_scaler(struct pic32_wdt *wdt) { u32 v = readl(wdt->regs + WDTCON_REG); return (v >> WDTCON_RMPS_SHIFT) & WDTCON_RMPS_MASK; } static inline u32 pic32_wdt_get_clk_id(struct pic32_wdt *wdt) { u32 v = readl(wdt->regs + WDTCON_REG); return (v >> WDTCON_RMCS_SHIFT) & WDTCON_RMCS_MASK; } static int pic32_wdt_bootstatus(struct pic32_wdt *wdt) { u32 v = readl(wdt->rst_base); writel(RESETCON_WDT_TIMEOUT, PIC32_CLR(wdt->rst_base)); return v & RESETCON_WDT_TIMEOUT; } static u32 pic32_wdt_get_timeout_secs(struct pic32_wdt *wdt, struct device *dev) { unsigned long rate; u32 period, ps, terminal; rate = clk_get_rate(wdt->clk); dev_dbg(dev, "wdt: clk_id %d, clk_rate %lu (prescale)\n", pic32_wdt_get_clk_id(wdt), rate); /* default, prescaler of 32 (i.e. div-by-32) is implicit. */ rate >>= 5; if (!rate) return 0; /* calculate terminal count from postscaler. */ ps = pic32_wdt_get_post_scaler(wdt); terminal = BIT(ps); /* find time taken (in secs) to reach terminal count */ period = terminal / rate; dev_dbg(dev, "wdt: clk_rate %lu (postscale) / terminal %d, timeout %dsec\n", rate, terminal, period); return period; } static void pic32_wdt_keepalive(struct pic32_wdt *wdt) { /* write key through single half-word */ writew(WDTCON_CLR_KEY, wdt->regs + WDTCON_REG + 2); } static int pic32_wdt_start(struct watchdog_device *wdd) { struct pic32_wdt *wdt = watchdog_get_drvdata(wdd); writel(WDTCON_ON, PIC32_SET(wdt->regs + WDTCON_REG)); pic32_wdt_keepalive(wdt); return 0; } static int pic32_wdt_stop(struct watchdog_device *wdd) { struct pic32_wdt *wdt = watchdog_get_drvdata(wdd); writel(WDTCON_ON, PIC32_CLR(wdt->regs + WDTCON_REG)); /* * Cannot touch registers in the CPU cycle following clearing the * ON bit. */ nop(); return 0; } static int pic32_wdt_ping(struct watchdog_device *wdd) { struct pic32_wdt *wdt = watchdog_get_drvdata(wdd); pic32_wdt_keepalive(wdt); return 0; } static const struct watchdog_ops pic32_wdt_fops = { .owner = THIS_MODULE, .start = pic32_wdt_start, .stop = pic32_wdt_stop, .ping = pic32_wdt_ping, }; static const struct watchdog_info pic32_wdt_ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_CARDRESET, .identity = "PIC32 Watchdog", }; static struct watchdog_device pic32_wdd = { .info = &pic32_wdt_ident, .ops = &pic32_wdt_fops, }; static const struct of_device_id pic32_wdt_dt_ids[] = { { .compatible = "microchip,pic32mzda-wdt", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, pic32_wdt_dt_ids); static int pic32_wdt_drv_probe(struct platform_device *pdev) { int ret; struct watchdog_device *wdd = &pic32_wdd; struct pic32_wdt *wdt; struct resource *mem; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); wdt->regs = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(wdt->regs)) return PTR_ERR(wdt->regs); wdt->rst_base = devm_ioremap(&pdev->dev, PIC32_BASE_RESET, 0x10); if (!wdt->rst_base) return -ENOMEM; wdt->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(wdt->clk)) { dev_err(&pdev->dev, "clk not found\n"); return PTR_ERR(wdt->clk); } ret = clk_prepare_enable(wdt->clk); if (ret) { dev_err(&pdev->dev, "clk enable failed\n"); return ret; } if (pic32_wdt_is_win_enabled(wdt)) { dev_err(&pdev->dev, "windowed-clear mode is not supported.\n"); ret = -ENODEV; goto out_disable_clk; } wdd->timeout = pic32_wdt_get_timeout_secs(wdt, &pdev->dev); if (!wdd->timeout) { dev_err(&pdev->dev, "failed to read watchdog register timeout\n"); ret = -EINVAL; goto out_disable_clk; } dev_info(&pdev->dev, "timeout %d\n", wdd->timeout); wdd->bootstatus = pic32_wdt_bootstatus(wdt) ? WDIOF_CARDRESET : 0; watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT); watchdog_set_drvdata(wdd, wdt); ret = watchdog_register_device(wdd); if (ret) { dev_err(&pdev->dev, "watchdog register failed, err %d\n", ret); goto out_disable_clk; } platform_set_drvdata(pdev, wdd); return 0; out_disable_clk: clk_disable_unprepare(wdt->clk); return ret; } static int pic32_wdt_drv_remove(struct platform_device *pdev) { struct watchdog_device *wdd = platform_get_drvdata(pdev); struct pic32_wdt *wdt = watchdog_get_drvdata(wdd); watchdog_unregister_device(wdd); clk_disable_unprepare(wdt->clk); return 0; } static struct platform_driver pic32_wdt_driver = { .probe = pic32_wdt_drv_probe, .remove = pic32_wdt_drv_remove, .driver = { .name = "pic32-wdt", .of_match_table = of_match_ptr(pic32_wdt_dt_ids), } }; module_platform_driver(pic32_wdt_driver); MODULE_AUTHOR("Joshua Henderson "); MODULE_DESCRIPTION("Microchip PIC32 Watchdog Timer"); MODULE_LICENSE("GPL"); s='commit-subject'>Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP hotplug update from Thomas Gleixner: "This contains a trivial typo fix and an extension to the core code for dynamically allocating states in the prepare stage. The extension is necessary right now because we need a proper way to unbreak LTTNG, which iscurrently non functional due to the removal of the notifiers. Surely it's out of tree, but it's widely used by distros. The simple solution would have been to reserve a state for LTTNG, but I'm not fond about unused crap in the kernel and the dynamic range, which we admittedly should have done right away, allows us to remove quite some of the hardcoded states, i.e. those which have no ordering requirements. So doing the right thing now is better than having an smaller intermediate solution which needs to be reworked anyway" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Provide dynamic range for prepare stage perf/x86/amd/ibs: Fix typo after cleanup state names in cpu/hotplug
Diffstat (limited to 'fs/autofs4/Makefile')