[PATCH 1/2] watchdog: octeontx_wdt: Add MIPS Octeon support

[Stefan Roese <sr@denx.de>]

This patch adds support for the Marvell Octeon watchdog driver, which
currently only support the ARM64 Octeon TX & TX2 platforms. Since the
IP is pretty similar, it makes sense to extend this driver to also
support the MIPS Octeon SoC.

A follow-up patch will enable this watchdog support on the EBB7304
eval board.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>
---
 drivers/watchdog/Kconfig        |  9 ++---
 drivers/watchdog/octeontx_wdt.c | 67 ++++++++++++++++++++++++---------
 2 files changed, 53 insertions(+), 23 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c3eb8a8aec1b..2c6116fb7f9c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -213,14 +213,13 @@ config WDT_NPCM
 	  It performs full SoC reset.
 
 config WDT_OCTEONTX
-	bool "OcteonTX core watchdog support"
-	depends on WDT && (ARCH_OCTEONTX || ARCH_OCTEONTX2)
+	bool "Octeon core watchdog support"
+	depends on WDT && (ARCH_OCTEON || ARCH_OCTEONTX || ARCH_OCTEONTX2)
 	default y
 	imply WATCHDOG
 	help
-	  This enables OcteonTX watchdog driver, which can be
-	  found on OcteonTX/TX2 chipsets and inline with driver model.
-	  Only supports watchdog reset.
+	  This enables the Octeon watchdog driver, which can be found on
+	  various Octeon parts such as Octeon II/III and OcteonTX/TX2.
 
 config WDT_OMAP3
 	bool "TI OMAP watchdog timer support"
diff --git a/drivers/watchdog/octeontx_wdt.c b/drivers/watchdog/octeontx_wdt.c
index 01b244db8075..c79d9539c13f 100644
--- a/drivers/watchdog/octeontx_wdt.c
+++ b/drivers/watchdog/octeontx_wdt.c
@@ -15,16 +15,22 @@
 
 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_data {
+	u32 wdog_offset;
+	u32 poke_offset;
+	int timer_shift;
+	bool has_clk;
+};
+
 struct octeontx_wdt {
 	void __iomem *reg;
+	const struct octeontx_wdt_data *data;
 	struct clk clk;
 };
 
@@ -34,12 +40,16 @@ static int octeontx_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
 	u64 clk_rate, val;
 	u64 tout_wdog;
 
-	clk_rate = clk_get_rate(&priv->clk);
-	if (IS_ERR_VALUE(clk_rate))
-		return -EINVAL;
+	if (priv->data->has_clk) {
+		clk_rate = clk_get_rate(&priv->clk);
+		if (IS_ERR_VALUE(clk_rate))
+			return -EINVAL;
+	} else {
+		clk_rate = gd->bus_clk;
+	}
 
-	/* Watchdog counts in 1024 cycle steps */
-	tout_wdog = (clk_rate * timeout_ms / 1000) >> 10;
+	/* Watchdog counts in configured cycle steps */
+	tout_wdog = (clk_rate * timeout_ms / 1000) >> priv->data->timer_shift;
 
 	/*
 	 * We can only specify the upper 16 bits of a 24 bit value.
@@ -54,7 +64,7 @@ static int octeontx_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
 	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);
+	writeq(val, priv->reg + priv->data->wdog_offset);
 
 	return 0;
 }
@@ -63,7 +73,7 @@ static int octeontx_wdt_stop(struct udevice *dev)
 {
 	struct octeontx_wdt *priv = dev_get_priv(dev);
 
-	writeq(0, priv->reg + CORE0_WDOG_OFFSET);
+	writeq(0, priv->reg + priv->data->wdog_offset);
 
 	return 0;
 }
@@ -82,7 +92,7 @@ static int octeontx_wdt_reset(struct udevice *dev)
 {
 	struct octeontx_wdt *priv = dev_get_priv(dev);
 
-	writeq(~0ULL, priv->reg + CORE0_POKE_OFFSET);
+	writeq(~0ULL, priv->reg + priv->data->poke_offset);
 
 	return 0;
 }
@@ -103,6 +113,10 @@ static int octeontx_wdt_probe(struct udevice *dev)
 	if (!priv->reg)
 		return -EINVAL;
 
+	priv->data = (void *)dev_get_driver_data(dev);
+	if (!priv->data)
+		return -EINVAL;
+
 	/*
 	 * Save base register address in reg masking lower 20 bits
 	 * as 0xa0000 appears when extracted from the DT
@@ -110,13 +124,15 @@ static int octeontx_wdt_probe(struct udevice *dev)
 	priv->reg = (void __iomem *)(((u64)priv->reg &
 				      ~CORE0_POKE_OFFSET_MASK));
 
-	ret = clk_get_by_index(dev, 0, &priv->clk);
-	if (ret < 0)
-		return ret;
+	if (priv->data->has_clk) {
+		ret = clk_get_by_index(dev, 0, &priv->clk);
+		if (ret < 0)
+			return ret;
 
-	ret = clk_enable(&priv->clk);
-	if (ret)
-		return ret;
+		ret = clk_enable(&priv->clk);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
@@ -128,8 +144,23 @@ static const struct wdt_ops octeontx_wdt_ops = {
 	.expire_now = octeontx_wdt_expire_now,
 };
 
+static const struct octeontx_wdt_data octeontx_data = {
+	.wdog_offset = 0x40000,
+	.poke_offset = 0x50000,
+	.timer_shift = 10,
+	.has_clk = true,
+};
+
+static const struct octeontx_wdt_data octeon_data = {
+	.wdog_offset = 0x20000,
+	.poke_offset = 0x30000,
+	.timer_shift = 10,
+	.has_clk = false,
+};
+
 static const struct udevice_id octeontx_wdt_ids[] = {
-	{ .compatible = "arm,sbsa-gwdt" },
+	{ .compatible = "arm,sbsa-gwdt", .data = (ulong)&octeontx_data },
+	{ .compatible = "cavium,octeon-7890-ciu3", .data = (ulong)&octeon_data },
 	{}
 };
 
@@ -138,7 +169,7 @@ U_BOOT_DRIVER(wdt_octeontx) = {
 	.id = UCLASS_WDT,
 	.of_match = octeontx_wdt_ids,
 	.ops = &octeontx_wdt_ops,
-	.priv_auto	= sizeof(struct octeontx_wdt),
+	.priv_auto = sizeof(struct octeontx_wdt),
 	.probe = octeontx_wdt_probe,
 	.remove = octeontx_wdt_remove,
 	.flags = DM_FLAG_OS_PREPARE,
-- 
2.36.1