diff options
Diffstat (limited to 'roms/u-boot/drivers/watchdog/omap_wdt.c')
-rw-r--r-- | roms/u-boot/drivers/watchdog/omap_wdt.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/watchdog/omap_wdt.c b/roms/u-boot/drivers/watchdog/omap_wdt.c new file mode 100644 index 000000000..ca2bc7cfb --- /dev/null +++ b/roms/u-boot/drivers/watchdog/omap_wdt.c @@ -0,0 +1,268 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * omap_wdt.c + * + * (C) Copyright 2013 + * Heiko Schocher, DENX Software Engineering, hs@denx.de. + * + * Based on: + * + * Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog + * + * commit 2d991a164a61858012651e13c59521975504e260 + * Author: Bill Pemberton <wfp5p@virginia.edu> + * Date: Mon Nov 19 13:21:41 2012 -0500 + * + * watchdog: remove use of __devinit + * + * CONFIG_HOTPLUG is going away as an option so __devinit is no longer + * needed. + * + * Author: MontaVista Software, Inc. + * <gdavis@mvista.com> or <source@mvista.com> + * + * History: + * + * 20030527: George G. Davis <gdavis@mvista.com> + * Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c + * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> + * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk> + * + * Copyright (c) 2004 Texas Instruments. + * 1. Modified to support OMAP1610 32-KHz watchdog timer + * 2. Ported to 2.6 kernel + * + * Copyright (c) 2005 David Brownell + * Use the driver model and standard identifiers; handle bigger timeouts. + */ + +#include <common.h> +#include <log.h> +#include <watchdog.h> +#include <asm/arch/hardware.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/arch/cpu.h> +#include <wdt.h> +#include <dm.h> +#include <errno.h> + +/* Hardware timeout in seconds */ +#define WDT_HW_TIMEOUT 60 + +#if !CONFIG_IS_ENABLED(WDT) +static unsigned int wdt_trgr_pattern = 0x1234; + +void hw_watchdog_reset(void) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + + /* + * Somebody just triggered watchdog reset and write to WTGR register + * is in progress. It is resetting right now, no need to trigger it + * again + */ + if ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR) + return; + + wdt_trgr_pattern = ~wdt_trgr_pattern; + writel(wdt_trgr_pattern, &wdt->wdtwtgr); + + /* + * Don't wait for posted write to complete, i.e. don't check + * WDT_WWPS_PEND_WTGR bit in WWPS register. There is no writes to + * WTGR register outside of this func, and if entering it + * we see WDT_WWPS_PEND_WTGR bit set, it means watchdog reset + * was just triggered. This prevents us from wasting time in busy + * polling of WDT_WWPS_PEND_WTGR bit. + */ +} + +static int omap_wdt_set_timeout(unsigned int timeout) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + u32 pre_margin = GET_WLDR_VAL(timeout); + + /* just count up at 32 KHz */ + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + + writel(pre_margin, &wdt->wdtwldr); + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + + return 0; +} + +void hw_watchdog_disable(void) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + + /* + * Disable watchdog + */ + writel(0xAAAA, &wdt->wdtwspr); + while (readl(&wdt->wdtwwps) != 0x0) + ; + writel(0x5555, &wdt->wdtwspr); + while (readl(&wdt->wdtwwps) != 0x0) + ; +} + +void hw_watchdog_init(void) +{ + struct wd_timer *wdt = (struct wd_timer *)WDT_BASE; + + /* + * Make sure the watchdog is disabled. This is unfortunately required + * because writing to various registers with the watchdog running has no + * effect. + */ + hw_watchdog_disable(); + + /* initialize prescaler */ + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + + writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &wdt->wdtwclr); + while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + + omap_wdt_set_timeout(WDT_HW_TIMEOUT); + + /* Sequence to enable the watchdog */ + writel(0xBBBB, &wdt->wdtwspr); + while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; + + writel(0x4444, &wdt->wdtwspr); + while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; +} + +void watchdog_reset(void) +{ + hw_watchdog_reset(); +} + +#else + +static int omap3_wdt_reset(struct udevice *dev) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + + /* + * Somebody just triggered watchdog reset and write to WTGR register + * is in progress. It is resetting right now, no need to trigger it + * again + */ + if ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WTGR) + return 0; + + priv->wdt_trgr_pattern = ~(priv->wdt_trgr_pattern); + writel(priv->wdt_trgr_pattern, &priv->regs->wdtwtgr); + /* + * Don't wait for posted write to complete, i.e. don't check + * WDT_WWPS_PEND_WTGR bit in WWPS register. There is no writes to + * WTGR register outside of this func, and if entering it + * we see WDT_WWPS_PEND_WTGR bit set, it means watchdog reset + * was just triggered. This prevents us from wasting time in busy + * polling of WDT_WWPS_PEND_WTGR bit. + */ + return 0; +} + +static int omap3_wdt_stop(struct udevice *dev) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + + /* disable watchdog */ + writel(0xAAAA, &priv->regs->wdtwspr); + while (readl(&priv->regs->wdtwwps) != 0x0) + ; + writel(0x5555, &priv->regs->wdtwspr); + while (readl(&priv->regs->wdtwwps) != 0x0) + ; + return 0; +} + +static int omap3_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + u32 pre_margin = GET_WLDR_VAL(timeout_ms / 1000); + /* + * Make sure the watchdog is disabled. This is unfortunately required + * because writing to various registers with the watchdog running has + * no effect. + */ + omap3_wdt_stop(dev); + + /* initialize prescaler */ + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + + writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &priv->regs->wdtwclr); + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + /* just count up at 32 KHz */ + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + + writel(pre_margin, &priv->regs->wdtwldr); + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + /* Sequence to enable the watchdog */ + writel(0xBBBB, &priv->regs->wdtwspr); + while ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; + + writel(0x4444, &priv->regs->wdtwspr); + while ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; + + /* Trigger the watchdog to actually reload the counter. */ + while ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WTGR) + ; + + priv->wdt_trgr_pattern = ~(priv->wdt_trgr_pattern); + writel(priv->wdt_trgr_pattern, &priv->regs->wdtwtgr); + + while ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WTGR) + ; + + return 0; +} + +static int omap3_wdt_probe(struct udevice *dev) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + + priv->regs = dev_read_addr_ptr(dev); + if (!priv->regs) + return -EINVAL; + + priv->wdt_trgr_pattern = 0x1234; + debug("%s: Probing wdt%u\n", __func__, dev_seq(dev)); + return 0; +} + +static const struct wdt_ops omap3_wdt_ops = { + .start = omap3_wdt_start, + .stop = omap3_wdt_stop, + .reset = omap3_wdt_reset, +}; + +static const struct udevice_id omap3_wdt_ids[] = { + { .compatible = "ti,omap3-wdt" }, + { } +}; + +U_BOOT_DRIVER(omap3_wdt) = { + .name = "omap3_wdt", + .id = UCLASS_WDT, + .of_match = omap3_wdt_ids, + .ops = &omap3_wdt_ops, + .probe = omap3_wdt_probe, + .priv_auto = sizeof(struct omap3_wdt_priv), +}; +#endif /* !CONFIG_IS_ENABLED(WDT) */ |