Convert the Watchdog driver for AT91SAM9x processors to support the driver model and device tree

Signed-off-by: Prasanthi Chellakumar prasanthi.chellakumar@microchip.com --- arch/arm/mach-at91/include/mach/at91_wdt.h | 12 +++- drivers/watchdog/Kconfig | 7 ++ drivers/watchdog/Makefile | 2 +- drivers/watchdog/at91sam9_wdt.c | 105 +++++++++++++++++++++-------- 4 files changed, 95 insertions(+), 31 deletions(-)

diff --git a/arch/arm/mach-at91/include/mach/at91_wdt.h b/arch/arm/mach-at91/include/mach/at91_wdt.h index 99b0cc8..df9f131 100644 --- a/arch/arm/mach-at91/include/mach/at91_wdt.h +++ b/arch/arm/mach-at91/include/mach/at91_wdt.h @@ -4,7 +4,7 @@ * * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com * Copyright (C) 2007 Andrew Victor - * Copyright (C) 2007 Atmel Corporation. + * Copyright (C) 2018 Microchip Technology Inc. * * Watchdog Timer (WDT) - System peripherals regsters. * Based on AT91SAM9261 datasheet revision D. @@ -27,15 +27,21 @@ typedef struct at91_wdt {

#endif

+/* Watchdog Control Register */ +#define AT91_WDT_CR 0x00 #define AT91_WDT_CR_WDRSTT 1 #define AT91_WDT_CR_KEY 0xa5000000 /* KEY Password */

-#define AT91_WDT_MR_WDV(x) (x & 0xfff) +/* Watchdog Mode Register*/ +#define AT91_WDT_MR 0X04 +#define AT91_WDT_MR_WDV (0xfff << 0) +#define AT91_WDT_MR_SET_WDV(x) ((x) & AT91_WDT_MR_WDV) #define AT91_WDT_MR_WDFIEN 0x00001000 #define AT91_WDT_MR_WDRSTEN 0x00002000 #define AT91_WDT_MR_WDRPROC 0x00004000 #define AT91_WDT_MR_WDDIS 0x00008000 -#define AT91_WDT_MR_WDD(x) ((x & 0xfff) << 16) +#define AT91_WDT_MR_WDD (0xfff << 16) +#define AT91_WDT_MR_SET_WDD(x) (((x) << 16) & AT91_WDT_MR_WDD) #define AT91_WDT_MR_WDDBGHLT 0x10000000 #define AT91_WDT_MR_WDIDLEHLT 0x20000000

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index d545b3e..001a8d0 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -111,4 +111,11 @@ config XILINX_TB_WATCHDOG Select this to enable Xilinx Axi watchdog timer, which can be found on some Xilinx Microblaze Platforms.

+config WDT_AT91 + bool "AT91 watchdog timer support" + depends on WDT + help + Select this to enable Microchip watchdog timer, which can be found on + some AT91 devices. + endmenu diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index f405f51..3f4fd59 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -3,7 +3,7 @@ # (C) Copyright 2008 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.

-obj-$(CONFIG_AT91SAM9_WATCHDOG) += at91sam9_wdt.o +obj-$(CONFIG_WDT_AT91) += at91sam9_wdt.o obj-$(CONFIG_FTWDT010_WATCHDOG) += ftwdt010_wdt.o ifneq (,$(filter $(SOC), mx31 mx35 mx5 mx6 mx7 vf610)) obj-y += imx_watchdog.o diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c index fca2849..d3f8fa6 100644 --- a/drivers/watchdog/at91sam9_wdt.c +++ b/drivers/watchdog/at91sam9_wdt.c @@ -2,7 +2,7 @@ /* * [origin: Linux kernel drivers/watchdog/at91sam9_wdt.c] * - * Watchdog driver for Atmel AT91SAM9x processors. + * Watchdog driver for AT91SAM9x processors. * * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com * Copyright (C) 2008 Renaud CERRATO r.cerrato@til-technologies.fr @@ -14,38 +14,47 @@ * write to this register. Inform Linux to it too */

-#include <common.h> -#include <watchdog.h> -#include <asm/arch/hardware.h> #include <asm/io.h> #include <asm/arch/at91_wdt.h> +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <wdt.h> + +DECLARE_GLOBAL_DATA_PTR;

/* * AT91SAM9 watchdog runs a 12bit counter @ 256Hz, * use this to convert a watchdog - * value from/to milliseconds. + * value from seconds. */ -#define ms_to_ticks(t) (((t << 8) / 1000) - 1) -#define ticks_to_ms(t) (((t + 1) * 1000) >> 8) +#define WDT_SEC2TICKS(s) (((s) << 8) - 1)

/* Hardware timeout in seconds */ -#if !defined(CONFIG_AT91_HW_WDT_TIMEOUT) -#define WDT_HW_TIMEOUT 2 -#else -#define WDT_HW_TIMEOUT CONFIG_AT91_HW_WDT_TIMEOUT -#endif +#define WDT_MAX_TIMEOUT 16 +#define WDT_MIN_TIMEOUT 0 + +struct at91_wdt_priv { + void __iomem *regs; + u32 regval; +};

/* * Set the watchdog time interval in 1/256Hz (write-once) * Counter is 12 bit. */ -static int at91_wdt_settimeout(unsigned int timeout) +static int at91_wdt_start(struct udevice *dev, u64 timeout_s, ulong flags) { - unsigned int reg; - at91_wdt_t *wd = (at91_wdt_t *) ATMEL_BASE_WDT; + struct at91_wdt_priv *priv = dev_get_priv(dev); + u32 timeout = WDT_SEC2TICKS(timeout_s); + + if (timeout_s > WDT_MAX_TIMEOUT || timeout_s < WDT_MIN_TIMEOUT) { + printf("Invalid watchdog counter value\n"); + return -1; + }

/* Check if disabled */ - if (readl(&wd->mr) & AT91_WDT_MR_WDDIS) { + if (readl(priv->regs + AT91_WDT_MR) & AT91_WDT_MR_WDDIS) { printf("sorry, watchdog is disabled\n"); return -1; } @@ -56,25 +65,67 @@ static int at91_wdt_settimeout(unsigned int timeout) * Since WDV is a 12-bit counter, the maximum period is * 4096 / 256 = 16 seconds. */ + priv->regval &= ~AT91_WDT_MR_WDV; + priv->regval &= ~AT91_WDT_MR_WDD; + priv->regval |= AT91_WDT_MR_SET_WDV(timeout); + priv->regval |= AT91_WDT_MR_SET_WDD(timeout); + priv->regval |= AT91_WDT_MR_WDDBGHLT; + priv->regval |= AT91_WDT_MR_WDIDLEHLT; + priv->regval |= AT91_WDT_MR_WDRSTEN;

- reg = AT91_WDT_MR_WDRSTEN /* causes watchdog reset */ - | AT91_WDT_MR_WDDBGHLT /* disabled in debug mode */ - | AT91_WDT_MR_WDD(0xfff) /* restart at any time */ - | AT91_WDT_MR_WDV(timeout); /* timer value */ + writel(priv->regval, priv->regs + AT91_WDT_MR);

- writel(reg, &wd->mr); + return 0; +} + +static int at91_wdt_stop(struct udevice *dev) +{ + struct at91_wdt_priv *priv = dev_get_priv(dev); + + /* Disable Watchdog Timer */ + priv->regval |= AT91_WDT_MR_WDDIS; + writel(priv->regval, priv->regs + AT91_WDT_MR);

return 0; }

-void hw_watchdog_reset(void) +static int at91_wdt_reset(struct udevice *dev) { - at91_wdt_t *wd = (at91_wdt_t *) ATMEL_BASE_WDT; - writel(AT91_WDT_CR_WDRSTT | AT91_WDT_CR_KEY, &wd->cr); + struct at91_wdt_priv *priv = dev_get_priv(dev); + + writel(AT91_WDT_CR_WDRSTT | AT91_WDT_CR_KEY, priv->regs + AT91_WDT_CR); + + return 0; }

-void hw_watchdog_init(void) +static const struct wdt_ops at91_wdt_ops = { + .start = at91_wdt_start, + .stop = at91_wdt_stop, + .reset = at91_wdt_reset, +}; + +static const struct udevice_id at91_wdt_ids[] = { + { .compatible = "atmel,at91sam9260-wdt" }, + {} +}; + +static int at91_wdt_probe(struct udevice *dev) { - /* 16 seconds timer, resets enabled */ - at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000)); + struct at91_wdt_priv *priv = dev_get_priv(dev); + + priv->regs = dev_remap_addr(dev); + if (!priv->regs) + return -EINVAL; + debug("%s: Probing wdt%u\n", __func__, dev->seq); + + return 0; } + +U_BOOT_DRIVER(at91_wdt) = { + .name = "at91_wdt", + .id = UCLASS_WDT, + .of_match = at91_wdt_ids, + .priv_auto_alloc_size = sizeof(struct at91_wdt_priv), + .ops = &at91_wdt_ops, + .probe = at91_wdt_probe, +};