[U-Boot] [PATCH v1] arm: at91: wdt: Convert watchdog driver to dm
Prasanthi Chellakumar
Prasanthi.Chellakumar at microchip.com
Thu Jul 26 21:56:27 UTC 2018
Convert the Watchdog driver for AT91SAM9x processors to support
the driver model and device tree
Signed-off-by: Prasanthi Chellakumar <prasanthi.chellakumar at 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 at 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 at 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 at jcrosoft.com>
* Copyright (C) 2008 Renaud CERRATO r.cerrato at 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,
+};
--
2.7.4
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