| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com> |
| * |
| * Derived from linux/drivers/watchdog/bcm63xx_wdt.c: |
| * Copyright (C) 2007 Miguel Gaio <miguel.gaio@efixo.com> |
| * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org> |
| */ |
| |
| #include <common.h> |
| #include <dm.h> |
| #include <wdt.h> |
| #include <clk.h> |
| #include <asm/io.h> |
| |
| /* WDT Value register */ |
| #define WDT_VAL_REG 0x0 |
| #define WDT_VAL_MIN 0x00000002 |
| #define WDT_VAL_MAX 0xfffffffe |
| |
| /* WDT Control register */ |
| #define WDT_CTL_REG 0x4 |
| #define WDT_CTL_START1_MASK 0x0000ff00 |
| #define WDT_CTL_START2_MASK 0x000000ff |
| #define WDT_CTL_STOP1_MASK 0x0000ee00 |
| #define WDT_CTL_STOP2_MASK 0x000000ee |
| |
| struct bcm6345_wdt_priv { |
| void __iomem *regs; |
| unsigned long clk_rate; |
| }; |
| |
| static int bcm6345_wdt_reset(struct udevice *dev) |
| { |
| struct bcm6345_wdt_priv *priv = dev_get_priv(dev); |
| |
| writel(WDT_CTL_START1_MASK, priv->regs + WDT_CTL_REG); |
| writel(WDT_CTL_START2_MASK, priv->regs + WDT_CTL_REG); |
| |
| return 0; |
| } |
| |
| static int bcm6345_wdt_start(struct udevice *dev, u64 timeout, ulong flags) |
| { |
| struct bcm6345_wdt_priv *priv = dev_get_priv(dev); |
| u32 val = priv->clk_rate / 1000 * timeout; |
| |
| if (val < WDT_VAL_MIN) { |
| debug("watchdog won't fire with less than 2 ticks\n"); |
| val = WDT_VAL_MIN; |
| } else if (val > WDT_VAL_MAX) { |
| debug("maximum watchdog timeout exceeded\n"); |
| val = WDT_VAL_MAX; |
| } |
| |
| writel(val, priv->regs + WDT_VAL_REG); |
| |
| return bcm6345_wdt_reset(dev); |
| } |
| |
| static int bcm6345_wdt_expire_now(struct udevice *dev, ulong flags) |
| { |
| return bcm6345_wdt_start(dev, WDT_VAL_MIN, flags); |
| } |
| |
| static int bcm6345_wdt_stop(struct udevice *dev) |
| { |
| struct bcm6345_wdt_priv *priv = dev_get_priv(dev); |
| |
| writel(WDT_CTL_STOP1_MASK, priv->regs + WDT_CTL_REG); |
| writel(WDT_CTL_STOP2_MASK, priv->regs + WDT_CTL_REG); |
| |
| return 0; |
| } |
| |
| static const struct wdt_ops bcm6345_wdt_ops = { |
| .expire_now = bcm6345_wdt_expire_now, |
| .reset = bcm6345_wdt_reset, |
| .start = bcm6345_wdt_start, |
| .stop = bcm6345_wdt_stop, |
| }; |
| |
| static const struct udevice_id bcm6345_wdt_ids[] = { |
| { .compatible = "brcm,bcm6345-wdt" }, |
| { /* sentinel */ } |
| }; |
| |
| static int bcm6345_wdt_probe(struct udevice *dev) |
| { |
| struct bcm6345_wdt_priv *priv = dev_get_priv(dev); |
| struct clk clk; |
| int ret; |
| |
| priv->regs = dev_remap_addr(dev); |
| if (!priv->regs) |
| return -EINVAL; |
| |
| ret = clk_get_by_index(dev, 0, &clk); |
| if (!ret) |
| priv->clk_rate = clk_get_rate(&clk); |
| else |
| return -EINVAL; |
| |
| bcm6345_wdt_stop(dev); |
| |
| return 0; |
| } |
| |
| U_BOOT_DRIVER(wdt_bcm6345) = { |
| .name = "wdt_bcm6345", |
| .id = UCLASS_WDT, |
| .of_match = bcm6345_wdt_ids, |
| .ops = &bcm6345_wdt_ops, |
| .priv_auto_alloc_size = sizeof(struct bcm6345_wdt_priv), |
| .probe = bcm6345_wdt_probe, |
| }; |