diff options
author | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
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committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/drivers/watchdog/mt7620_wdt.c | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/drivers/watchdog/mt7620_wdt.c')
-rw-r--r-- | roms/u-boot/drivers/watchdog/mt7620_wdt.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/watchdog/mt7620_wdt.c b/roms/u-boot/drivers/watchdog/mt7620_wdt.c new file mode 100644 index 000000000..fe89721dd --- /dev/null +++ b/roms/u-boot/drivers/watchdog/mt7620_wdt.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 MediaTek Inc. + * + * Author: Weijie Gao <weijie.gao@mediatek.com> + * + * Watchdog timer for MT7620 and earlier SoCs + */ + +#include <div64.h> +#include <dm.h> +#include <reset.h> +#include <wdt.h> +#include <linux/bitops.h> +#include <linux/io.h> + +struct mt7620_wdt { + void __iomem *regs; + u64 timeout; +}; + +#define TIMER_FREQ 40000000 +#define TIMER_MASK 0xffff +#define TIMER_PRESCALE 65536 + +#define TIMER_LOAD 0x00 +#define TIMER_CTL 0x08 + +#define TIMER_ENABLE BIT(7) +#define TIMER_MODE_SHIFT 4 +#define TIMER_MODE_WDT 3 +#define TIMER_PRESCALE_SHIFT 0 +#define TIMER_PRESCALE_65536 15 + +static void mt7620_wdt_ping(struct mt7620_wdt *priv) +{ + u64 val; + + val = (TIMER_FREQ / TIMER_PRESCALE) * priv->timeout; + do_div(val, 1000); + + if (val > TIMER_MASK) + val = TIMER_MASK; + + writel(val, priv->regs + TIMER_LOAD); +} + +static int mt7620_wdt_start(struct udevice *dev, u64 ms, ulong flags) +{ + struct mt7620_wdt *priv = dev_get_priv(dev); + + priv->timeout = ms; + mt7620_wdt_ping(priv); + + writel(TIMER_ENABLE | (TIMER_MODE_WDT << TIMER_MODE_SHIFT) | + (TIMER_PRESCALE_65536 << TIMER_PRESCALE_SHIFT), + priv->regs + TIMER_CTL); + + return 0; +} + +static int mt7620_wdt_stop(struct udevice *dev) +{ + struct mt7620_wdt *priv = dev_get_priv(dev); + + mt7620_wdt_ping(priv); + + clrbits_32(priv->regs + TIMER_CTL, TIMER_ENABLE); + + return 0; +} + +static int mt7620_wdt_reset(struct udevice *dev) +{ + struct mt7620_wdt *priv = dev_get_priv(dev); + + mt7620_wdt_ping(priv); + + return 0; +} + +static int mt7620_wdt_expire_now(struct udevice *dev, ulong flags) +{ + struct mt7620_wdt *priv = dev_get_priv(dev); + + mt7620_wdt_start(dev, 1, flags); + + /* + * 0 will disable the timer directly, a positive number must be used + * instead. Since the timer is a countdown timer, 1 (tick) is used. + * + * For a timer with input clock = 40MHz, 1 timer tick is short + * enough to trigger a timeout immediately. + * + * Restore prescale to 1, and load timer with 1 to trigger timeout. + */ + writel(TIMER_ENABLE | (TIMER_MODE_WDT << TIMER_MODE_SHIFT), + priv->regs + TIMER_CTL); + writel(1, priv->regs + TIMER_LOAD); + + return 0; +} + +static int mt7620_wdt_probe(struct udevice *dev) +{ + struct mt7620_wdt *priv = dev_get_priv(dev); + struct reset_ctl reset_wdt; + int ret; + + ret = reset_get_by_index(dev, 0, &reset_wdt); + if (!ret) + reset_deassert(&reset_wdt); + + priv->regs = dev_remap_addr(dev); + if (!priv->regs) + return -EINVAL; + + mt7620_wdt_stop(dev); + + return 0; +} + +static const struct wdt_ops mt7620_wdt_ops = { + .start = mt7620_wdt_start, + .reset = mt7620_wdt_reset, + .stop = mt7620_wdt_stop, + .expire_now = mt7620_wdt_expire_now, +}; + +static const struct udevice_id mt7620_wdt_ids[] = { + { .compatible = "mediatek,mt7620-wdt" }, + {} +}; + +U_BOOT_DRIVER(mt7620_wdt) = { + .name = "mt7620_wdt", + .id = UCLASS_WDT, + .of_match = mt7620_wdt_ids, + .probe = mt7620_wdt_probe, + .priv_auto = sizeof(struct mt7620_wdt), + .ops = &mt7620_wdt_ops, +}; |