/* * Ralink MT7621/MT7628 built-in hardware watchdog timer * * Copyright (C) 2014 John Crispin * * This driver was based on: drivers/watchdog/rt2880_wdt.c * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #define SYSC_RSTSTAT 0x38 #define WDT_RST_CAUSE BIT(1) #define RALINK_WDT_TIMEOUT 30 #define TIMER_REG_TMRSTAT 0x00 #define TIMER_REG_TMR1LOAD 0x24 #define TIMER_REG_TMR1CTL 0x20 #define TMR1CTL_ENABLE BIT(7) #define TMR1CTL_RESTART BIT(9) #define TMR1CTL_PRESCALE_SHIFT 16 static void __iomem *mt7621_wdt_base; static struct reset_control *mt7621_wdt_reset; static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static inline void rt_wdt_w32(unsigned reg, u32 val) { iowrite32(val, mt7621_wdt_base + reg); } static inline u32 rt_wdt_r32(unsigned reg) { return ioread32(mt7621_wdt_base + reg); } static int mt7621_wdt_ping(struct watchdog_device *w) { rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART); return 0; } static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t) { w->timeout = t; rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000); mt7621_wdt_ping(w); return 0; } static int mt7621_wdt_start(struct watchdog_device *w) { u32 t; /* set the prescaler to 1ms == 1000us */ rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT); mt7621_wdt_set_timeout(w, w->timeout); t = rt_wdt_r32(TIMER_REG_TMR1CTL); t |= TMR1CTL_ENABLE; rt_wdt_w32(TIMER_REG_TMR1CTL, t); return 0; } static int mt7621_wdt_stop(struct watchdog_device *w) { u32 t; mt7621_wdt_ping(w); t = rt_wdt_r32(TIMER_REG_TMR1CTL); t &= ~TMR1CTL_ENABLE; rt_wdt_w32(TIMER_REG_TMR1CTL, t); return 0; } static int mt7621_wdt_bootcause(void) { if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) return WDIOF_CARDRESET; return 0; } static struct watchdog_info mt7621_wdt_info = { .identity = "Mediatek Watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static struct watchdog_ops mt7621_wdt_ops = { .owner = THIS_MODULE, .start = mt7621_wdt_start, .stop = mt7621_wdt_stop, .ping = mt7621_wdt_ping, .set_timeout = mt7621_wdt_set_timeout, }; static struct watchdog_device mt7621_wdt_dev = { .info = &mt7621_wdt_info, .ops = &mt7621_wdt_ops, .min_timeout = 1, .max_timeout = 0xfffful / 1000, }; static int mt7621_wdt_probe(struct platform_device *pdev) { struct resource *res; int ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(mt7621_wdt_base)) return PTR_ERR(mt7621_wdt_base); mt7621_wdt_reset = devm_reset_control_get(&pdev->dev, NULL); if (!IS_ERR(mt7621_wdt_reset)) reset_control_deassert(mt7621_wdt_reset); mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause(); watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout, &pdev->dev); watchdog_set_nowayout(&mt7621_wdt_dev, nowayout); ret = watchdog_register_device(&mt7621_wdt_dev); return 0; } static int mt7621_wdt_remove(struct platform_device *pdev) { watchdog_unregister_device(&mt7621_wdt_dev); return 0; } static void mt7621_wdt_shutdown(struct platform_device *pdev) { mt7621_wdt_stop(&mt7621_wdt_dev); } static const struct of_device_id mt7621_wdt_match[] = { { .compatible = "mediatek,mt7621-wdt" }, {}, }; MODULE_DEVICE_TABLE(of, mt7621_wdt_match); static struct platform_driver mt7621_wdt_driver = { .probe = mt7621_wdt_probe, .remove = mt7621_wdt_remove, .shutdown = mt7621_wdt_shutdown, .driver = { .name = KBUILD_MODNAME, .of_match_table = mt7621_wdt_match, }, }; module_platform_driver(mt7621_wdt_driver); MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver"); MODULE_AUTHOR("John Crispin 477b0229ac9bc275f6f8d2c27a2d08b246fccd0e (patch) tree578e6574229ac57723e64545a824a0aa50127340 parent29b4817d4018df78086157ea3a55c1d9424a7cfc (diff)
mtd: introduce the mtd_pairing_scheme concept
MLC and TLC NAND devices are using NAND cells exposing more than one bit, but instead of attaching all the bits in a given cell to a single NAND page, each bit is usually attached to a different page. This concept is called 'page pairing', and has significant impacts on the flash storage usage. The main problem showed by these devices is that interrupting a page program operation may not only corrupt the page we are programming but also the page it is paired with, hence the need to expose to MTD users the pairing scheme information. The pairing APIs allows one to query pairing information attached to a given page (here called wunit), or the other way around (the wunit pointed by pairing information). It also provides several helpers to help the conversion between absolute offsets and wunits, and query the number of pairing groups. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reviewed-by: Brian Norris <computersforpeace@gmail.com>
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