u-boot/drivers/watchdog/ulp_wdog.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
*/
#include <common.h>
#include <cpu_func.h>
#include <asm/io.h>
#include <asm/arch/imx-regs.h>
#include <dm.h>
#include <wdt.h>
/*
* MX7ULP WDOG Register Map
*/
struct wdog_regs {
u32 cs;
u32 cnt;
u32 toval;
u32 win;
};
struct ulp_wdt_priv {
struct wdog_regs *wdog;
u32 clk_rate;
};
#define REFRESH_WORD0 0xA602 /* 1st refresh word */
#define REFRESH_WORD1 0xB480 /* 2nd refresh word */
#define UNLOCK_WORD0 0xC520 /* 1st unlock word */
#define UNLOCK_WORD1 0xD928 /* 2nd unlock word */
#define UNLOCK_WORD 0xD928C520 /* unlock word */
#define REFRESH_WORD 0xB480A602 /* refresh word */
#define WDGCS_WDGE BIT(7)
#define WDGCS_WDGUPDATE BIT(5)
#define WDGCS_RCS BIT(10)
#define WDGCS_ULK BIT(11)
#define WDOG_CS_PRES BIT(12)
#define WDGCS_CMD32EN BIT(13)
#define WDGCS_FLG BIT(14)
#define WDGCS_INT BIT(6)
#define WDG_BUS_CLK (0x0)
#define WDG_LPO_CLK (0x1)
#define WDG_32KHZ_CLK (0x2)
#define WDG_EXT_CLK (0x3)
#define CLK_RATE_1KHZ 1000
#define CLK_RATE_32KHZ 125
void hw_watchdog_set_timeout(u16 val)
{
/* setting timeout value */
struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
writel(val, &wdog->toval);
}
void ulp_watchdog_reset(struct wdog_regs *wdog)
{
if (readl(&wdog->cs) & WDGCS_CMD32EN) {
writel(REFRESH_WORD, &wdog->cnt);
} else {
dmb();
__raw_writel(REFRESH_WORD0, &wdog->cnt);
__raw_writel(REFRESH_WORD1, &wdog->cnt);
dmb();
}
}
void ulp_watchdog_init(struct wdog_regs *wdog, u16 timeout)
{
u32 cmd32 = 0;
if (readl(&wdog->cs) & WDGCS_CMD32EN) {
writel(UNLOCK_WORD, &wdog->cnt);
cmd32 = WDGCS_CMD32EN;
} else {
dmb();
__raw_writel(UNLOCK_WORD0, &wdog->cnt);
__raw_writel(UNLOCK_WORD1, &wdog->cnt);
dmb();
}
/* Wait WDOG Unlock */
while (!(readl(&wdog->cs) & WDGCS_ULK))
;
hw_watchdog_set_timeout(timeout);
writel(0, &wdog->win);
/* setting 1-kHz clock source, enable counter running, and clear interrupt */
if (IS_ENABLED(CONFIG_ARCH_IMX9))
writel((cmd32 | WDGCS_WDGE | WDGCS_WDGUPDATE | (WDG_LPO_CLK << 8) |
WDGCS_FLG | WDOG_CS_PRES | WDGCS_INT), &wdog->cs);
else
writel((cmd32 | WDGCS_WDGE | WDGCS_WDGUPDATE | (WDG_LPO_CLK << 8) |
WDGCS_FLG), &wdog->cs);
/* Wait WDOG reconfiguration */
while (!(readl(&wdog->cs) & WDGCS_RCS))
;
ulp_watchdog_reset(wdog);
}
void hw_watchdog_reset(void)
{
struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
ulp_watchdog_reset(wdog);
}
void hw_watchdog_init(void)
{
struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
ulp_watchdog_init(wdog, CONFIG_WATCHDOG_TIMEOUT_MSECS);
}
void reset_cpu(void)
{
struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
u32 cmd32 = 0;
if (readl(&wdog->cs) & WDGCS_CMD32EN) {
writel(UNLOCK_WORD, &wdog->cnt);
cmd32 = WDGCS_CMD32EN;
} else {
dmb();
__raw_writel(UNLOCK_WORD0, &wdog->cnt);
__raw_writel(UNLOCK_WORD1, &wdog->cnt);
dmb();
}
/* Wait WDOG Unlock */
while (!(readl(&wdog->cs) & WDGCS_ULK))
;
hw_watchdog_set_timeout(5); /* 5ms timeout for general; 40ms timeout for imx93 */
writel(0, &wdog->win);
/* enable counter running */
if (IS_ENABLED(CONFIG_ARCH_IMX9))
writel((cmd32 | WDGCS_WDGE | (WDG_LPO_CLK << 8) | WDOG_CS_PRES |
WDGCS_INT), &wdog->cs);
else
writel((cmd32 | WDGCS_WDGE | (WDG_LPO_CLK << 8)), &wdog->cs);
/* Wait WDOG reconfiguration */
while (!(readl(&wdog->cs) & WDGCS_RCS))
;
hw_watchdog_reset();
while (1);
}
static int ulp_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
{
struct ulp_wdt_priv *priv = dev_get_priv(dev);
u64 timeout = 0;
timeout = (timeout_ms * priv->clk_rate) / 1000;
if (timeout > U16_MAX)
return -EINVAL;
ulp_watchdog_init(priv->wdog, (u16)timeout);
return 0;
}
static int ulp_wdt_reset(struct udevice *dev)
{
struct ulp_wdt_priv *priv = dev_get_priv(dev);
ulp_watchdog_reset(priv->wdog);
return 0;
}
static int ulp_wdt_probe(struct udevice *dev)
{
struct ulp_wdt_priv *priv = dev_get_priv(dev);
priv->wdog = dev_read_addr_ptr(dev);
if (!priv->wdog)
return -EINVAL;
priv->clk_rate = (u32)dev_get_driver_data(dev);
if (!priv->clk_rate)
return -EINVAL;
return 0;
}
static const struct wdt_ops ulp_wdt_ops = {
.start = ulp_wdt_start,
.reset = ulp_wdt_reset,
};
static const struct udevice_id ulp_wdt_ids[] = {
{ .compatible = "fsl,imx7ulp-wdt", .data = CLK_RATE_1KHZ },
{ .compatible = "fsl,imx8ulp-wdt", .data = CLK_RATE_1KHZ },
{ .compatible = "fsl,imx93-wdt", .data = CLK_RATE_32KHZ },
{}
};
U_BOOT_DRIVER(ulp_wdt) = {
.name = "ulp_wdt",
.id = UCLASS_WDT,
.of_match = ulp_wdt_ids,
.priv_auto = sizeof(struct ulp_wdt_priv),
.probe = ulp_wdt_probe,
.ops = &ulp_wdt_ops,
};