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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * Copyright (C) 2013 Altera Corporation <www.altera.com>
- */
- #include <clk.h>
- #include <common.h>
- #include <dm.h>
- #include <reset.h>
- #include <wdt.h>
- #include <asm/io.h>
- #include <linux/bitops.h>
- #define DW_WDT_CR 0x00
- #define DW_WDT_TORR 0x04
- #define DW_WDT_CRR 0x0C
- #define DW_WDT_CR_EN_OFFSET 0x00
- #define DW_WDT_CR_RMOD_OFFSET 0x01
- #define DW_WDT_CRR_RESTART_VAL 0x76
- struct designware_wdt_priv {
- void __iomem *base;
- unsigned int clk_khz;
- struct reset_ctl_bulk resets;
- };
- /*
- * Set the watchdog time interval.
- * Counter is 32 bit.
- */
- static int designware_wdt_settimeout(void __iomem *base, unsigned int clk_khz,
- unsigned int timeout)
- {
- signed int i;
- /* calculate the timeout range value */
- i = fls(timeout * clk_khz - 1) - 16;
- i = clamp(i, 0, 15);
- writel(i | (i << 4), base + DW_WDT_TORR);
- return 0;
- }
- static void designware_wdt_enable(void __iomem *base)
- {
- writel(BIT(DW_WDT_CR_EN_OFFSET), base + DW_WDT_CR);
- }
- static unsigned int designware_wdt_is_enabled(void __iomem *base)
- {
- return readl(base + DW_WDT_CR) & BIT(0);
- }
- static void designware_wdt_reset_common(void __iomem *base)
- {
- if (designware_wdt_is_enabled(base))
- /* restart the watchdog counter */
- writel(DW_WDT_CRR_RESTART_VAL, base + DW_WDT_CRR);
- }
- #if !CONFIG_IS_ENABLED(WDT)
- void hw_watchdog_reset(void)
- {
- designware_wdt_reset_common((void __iomem *)CONFIG_DW_WDT_BASE);
- }
- void hw_watchdog_init(void)
- {
- /* reset to disable the watchdog */
- hw_watchdog_reset();
- /* set timer in miliseconds */
- designware_wdt_settimeout((void __iomem *)CONFIG_DW_WDT_BASE,
- CONFIG_DW_WDT_CLOCK_KHZ,
- CONFIG_WATCHDOG_TIMEOUT_MSECS);
- /* enable the watchdog */
- designware_wdt_enable((void __iomem *)CONFIG_DW_WDT_BASE);
- /* reset the watchdog */
- hw_watchdog_reset();
- }
- #else
- static int designware_wdt_reset(struct udevice *dev)
- {
- struct designware_wdt_priv *priv = dev_get_priv(dev);
- designware_wdt_reset_common(priv->base);
- return 0;
- }
- static int designware_wdt_stop(struct udevice *dev)
- {
- struct designware_wdt_priv *priv = dev_get_priv(dev);
- designware_wdt_reset(dev);
- writel(0, priv->base + DW_WDT_CR);
- if (CONFIG_IS_ENABLED(DM_RESET)) {
- int ret;
- ret = reset_assert_bulk(&priv->resets);
- if (ret)
- return ret;
- ret = reset_deassert_bulk(&priv->resets);
- if (ret)
- return ret;
- }
- return 0;
- }
- static int designware_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
- {
- struct designware_wdt_priv *priv = dev_get_priv(dev);
- designware_wdt_stop(dev);
- /* set timer in miliseconds */
- designware_wdt_settimeout(priv->base, priv->clk_khz, timeout);
- designware_wdt_enable(priv->base);
- /* reset the watchdog */
- return designware_wdt_reset(dev);
- }
- static int designware_wdt_probe(struct udevice *dev)
- {
- struct designware_wdt_priv *priv = dev_get_priv(dev);
- __maybe_unused int ret;
- priv->base = dev_remap_addr(dev);
- if (!priv->base)
- return -EINVAL;
- #if CONFIG_IS_ENABLED(CLK)
- struct clk clk;
- ret = clk_get_by_index(dev, 0, &clk);
- if (ret)
- return ret;
- ret = clk_enable(&clk);
- if (ret)
- goto err;
- priv->clk_khz = clk_get_rate(&clk) / 1000;
- if (!priv->clk_khz) {
- ret = -EINVAL;
- goto err;
- }
- #else
- priv->clk_khz = CONFIG_DW_WDT_CLOCK_KHZ;
- #endif
- if (CONFIG_IS_ENABLED(DM_RESET)) {
- ret = reset_get_bulk(dev, &priv->resets);
- if (ret)
- goto err;
- ret = reset_deassert_bulk(&priv->resets);
- if (ret)
- goto err;
- }
- /* reset to disable the watchdog */
- return designware_wdt_stop(dev);
- err:
- #if CONFIG_IS_ENABLED(CLK)
- clk_free(&clk);
- #endif
- return ret;
- }
- static const struct wdt_ops designware_wdt_ops = {
- .start = designware_wdt_start,
- .reset = designware_wdt_reset,
- .stop = designware_wdt_stop,
- };
- static const struct udevice_id designware_wdt_ids[] = {
- { .compatible = "snps,dw-wdt"},
- {}
- };
- U_BOOT_DRIVER(designware_wdt) = {
- .name = "designware_wdt",
- .id = UCLASS_WDT,
- .of_match = designware_wdt_ids,
- .priv_auto = sizeof(struct designware_wdt_priv),
- .probe = designware_wdt_probe,
- .ops = &designware_wdt_ops,
- .flags = DM_FLAG_PRE_RELOC,
- };
- #endif
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