watchdog: octeontx_wdt: Add support for start and stop

This patch enhances the Octeon TX/TX2 watchdog driver to fully enable
the WDT. With this changes, the "wdt" command is now also supported
on these platforms.

Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Suneel Garapati <sgarapati@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>

diff --git a/drivers/watchdog/octeontx_wdt.c b/drivers/watchdog/octeontx_wdt.c
index 1e0670e0c5c2ad7a0a661e7664d5b4dca69e5000..88708dc5e1c9071348a773646e2a7eb85d064ee9 100644 (file)
--- a/drivers/watchdog/octeontx_wdt.c
+++ b/drivers/watchdog/octeontx_wdt.c
@@ -5,25 +5,90 @@
  * https://spdx.org/licenses
  */
 
+#include <clk.h>
 #include <dm.h>
 #include <errno.h>
 #include <wdt.h>
 #include <asm/io.h>
+#include <linux/bitfield.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#define CORE0_WDOG_OFFSET      0x40000
 #define CORE0_POKE_OFFSET      0x50000
 #define CORE0_POKE_OFFSET_MASK 0xfffffULL
 
+#define WDOG_MODE              GENMASK_ULL(1, 0)
+#define WDOG_LEN               GENMASK_ULL(19, 4)
+#define WDOG_CNT               GENMASK_ULL(43, 20)
+
 struct octeontx_wdt {
        void __iomem *reg;
+       struct clk clk;
 };
 
+static int octeontx_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
+{
+       struct octeontx_wdt *priv = dev_get_priv(dev);
+       u64 clk_rate, val;
+       u64 tout_wdog;
+
+       clk_rate = clk_get_rate(&priv->clk);
+       if (IS_ERR_VALUE(clk_rate))
+               return -EINVAL;
+
+       /* Watchdog counts in 1024 cycle steps */
+       tout_wdog = (clk_rate * timeout_ms / 1000) >> 10;
+
+       /*
+        * We can only specify the upper 16 bits of a 24 bit value.
+        * Round up
+        */
+       tout_wdog = (tout_wdog + 0xff) >> 8;
+
+       /* If the timeout overflows the hardware limit, set max */
+       if (tout_wdog >= 0x10000)
+               tout_wdog = 0xffff;
+
+       val = FIELD_PREP(WDOG_MODE, 0x3) |
+               FIELD_PREP(WDOG_LEN, tout_wdog) |
+               FIELD_PREP(WDOG_CNT, tout_wdog << 8);
+       writeq(val, priv->reg + CORE0_WDOG_OFFSET);
+
+       return 0;
+}
+
+static int octeontx_wdt_stop(struct udevice *dev)
+{
+       struct octeontx_wdt *priv = dev_get_priv(dev);
+
+       writeq(0, priv->reg + CORE0_WDOG_OFFSET);
+
+       return 0;
+}
+
+static int octeontx_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+       octeontx_wdt_stop(dev);
+
+       /* Start with 100ms timeout to expire immediately */
+       octeontx_wdt_start(dev, 100, flags);
+
+       return 0;
+}
+
 static int octeontx_wdt_reset(struct udevice *dev)
 {
        struct octeontx_wdt *priv = dev_get_priv(dev);
 
-       writeq(~0ULL, priv->reg);
+       writeq(~0ULL, priv->reg + CORE0_POKE_OFFSET);
+
+       return 0;
+}
+
+static int octeontx_wdt_remove(struct udevice *dev)
+{
+       octeontx_wdt_stop(dev);
 
        return 0;
 }
@@ -31,24 +96,35 @@ static int octeontx_wdt_reset(struct udevice *dev)
 static int octeontx_wdt_probe(struct udevice *dev)
 {
        struct octeontx_wdt *priv = dev_get_priv(dev);
+       int ret;
 
        priv->reg = dev_remap_addr(dev);
        if (!priv->reg)
                return -EINVAL;
 
        /*
-        * Save core poke register address in reg (its not 0xa0000 as
-        * extracted from the DT but 0x50000 instead)
+        * Save base register address in reg masking lower 20 bits
+        * as 0xa0000 appears when extracted from the DT
         */
        priv->reg = (void __iomem *)(((u64)priv->reg &
-                                     ~CORE0_POKE_OFFSET_MASK) |
-                                    CORE0_POKE_OFFSET);
+                                     ~CORE0_POKE_OFFSET_MASK));
+
+       ret = clk_get_by_index(dev, 0, &priv->clk);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_enable(&priv->clk);
+       if (ret)
+               return ret;
 
        return 0;
 }
 
 static const struct wdt_ops octeontx_wdt_ops = {
        .reset = octeontx_wdt_reset,
+       .start = octeontx_wdt_start,
+       .stop = octeontx_wdt_stop,
+       .expire_now = octeontx_wdt_expire_now,
 };
 
 static const struct udevice_id octeontx_wdt_ids[] = {
@@ -63,4 +139,6 @@ U_BOOT_DRIVER(wdt_octeontx) = {
        .ops = &octeontx_wdt_ops,
        .priv_auto_alloc_size = sizeof(struct octeontx_wdt),
        .probe = octeontx_wdt_probe,
+       .remove = octeontx_wdt_remove,
+       .flags = DM_FLAG_OS_PREPARE,
 };