[PATCH 2/3] watchdog: qcom: add option for standalone watchdog not in timer block

[Thomas Pedersen <twp@codeaurora.org>]

From: Matthew McClintock <mmcclint@codeaurora.org>

Commit 0dfd582e026a ("watchdog: qcom: use timer devicetree binding") moved
to use the watchdog as a subset timer register block. Some devices have the
watchdog completely standalone with slightly different register offsets as
well so let's account for the differences here.

Signed-off-by: Matthew McClintock <mmcclint@codeaurora.org>
---
 drivers/watchdog/qcom-wdt.c | 73 ++++++++++++++++++++++++++++++++-------------
 1 file changed, 52 insertions(+), 21 deletions(-)

diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
index a043fa4..70e42ed 100644
--- a/drivers/watchdog/qcom-wdt.c
+++ b/drivers/watchdog/qcom-wdt.c
@@ -19,18 +19,40 @@
 #include <linux/platform_device.h>
 #include <linux/watchdog.h>
 
-#define WDT_RST		0x38
-#define WDT_EN		0x40
-#define WDT_STS		0x44
-#define WDT_BITE_TIME	0x5C
+enum wdt_reg {
+	WDT_RST,
+	WDT_EN,
+	WDT_STS,
+	WDT_BITE_TIME,
+};
+
+static const u32 reg_offset_data_apcs_tmr[] = {
+	[WDT_RST] = 0x38,
+	[WDT_EN] = 0x40,
+	[WDT_STS] = 0x44,
+	[WDT_BITE_TIME] = 0x5C,
+};
+
+static const u32 reg_offset_data_kpss[] = {
+	[WDT_RST] = 0x4,
+	[WDT_EN] = 0x8,
+	[WDT_STS] = 0xC,
+	[WDT_BITE_TIME] = 0x14,
+};
 
 struct qcom_wdt {
 	struct watchdog_device	wdd;
 	struct clk		*clk;
 	unsigned long		rate;
 	void __iomem		*base;
+	const u32		*layout;
 };
 
+static void __iomem *wdt_addr(struct qcom_wdt *wdt, enum wdt_reg reg)
+{
+	return wdt->base + wdt->layout[reg];
+}
+
 static inline
 struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd)
 {
@@ -41,10 +63,10 @@ static int qcom_wdt_start(struct watchdog_device *wdd)
 {
 	struct qcom_wdt *wdt = to_qcom_wdt(wdd);
 
-	writel(0, wdt->base + WDT_EN);
-	writel(1, wdt->base + WDT_RST);
-	writel(wdd->timeout * wdt->rate, wdt->base + WDT_BITE_TIME);
-	writel(1, wdt->base + WDT_EN);
+	writel(0, wdt_addr(wdt, WDT_EN));
+	writel(1, wdt_addr(wdt, WDT_RST));
+	writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BITE_TIME));
+	writel(1, wdt_addr(wdt, WDT_EN));
 	return 0;
 }
 
@@ -52,7 +74,7 @@ static int qcom_wdt_stop(struct watchdog_device *wdd)
 {
 	struct qcom_wdt *wdt = to_qcom_wdt(wdd);
 
-	writel(0, wdt->base + WDT_EN);
+	writel(0, wdt_addr(wdt, WDT_EN));
 	return 0;
 }
 
@@ -60,7 +82,7 @@ static int qcom_wdt_ping(struct watchdog_device *wdd)
 {
 	struct qcom_wdt *wdt = to_qcom_wdt(wdd);
 
-	writel(1, wdt->base + WDT_RST);
+	writel(1, wdt_addr(wdt, WDT_RST));
 	return 0;
 }
 
@@ -83,10 +105,10 @@ static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 	 */
 	timeout = 128 * wdt->rate / 1000;
 
-	writel(0, wdt->base + WDT_EN);
-	writel(1, wdt->base + WDT_RST);
-	writel(timeout, wdt->base + WDT_BITE_TIME);
-	writel(1, wdt->base + WDT_EN);
+	writel(0, wdt_addr(wdt, WDT_EN));
+	writel(1, wdt_addr(wdt, WDT_RST));
+	writel(timeout, wdt_addr(wdt, WDT_BITE_TIME));
+	writel(1, wdt_addr(wdt, WDT_EN));
 
 	/*
 	 * Actually make sure the above sequence hits hardware before sleeping.
@@ -114,14 +136,29 @@ static const struct watchdog_info qcom_wdt_info = {
 	.identity	= KBUILD_MODNAME,
 };
 
+static const struct of_device_id qcom_wdt_of_table[] = {
+	{ .compatible = "qcom,kpss-timer", .data = reg_offset_data_apcs_tmr },
+	{ .compatible = "qcom,scss-timer", .data = reg_offset_data_apcs_tmr },
+	{ .compatible = "qcom,kpss-standalone", .data = &reg_offset_data_kpss},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
+
 static int qcom_wdt_probe(struct platform_device *pdev)
 {
 	struct qcom_wdt *wdt;
 	struct resource *res;
 	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *match;
 	u32 percpu_offset;
 	int ret;
 
+	match = of_match_node(qcom_wdt_of_table, np);
+	if (!match) {
+		dev_err(&pdev->dev, "Unsupported QCOM WDT module\n");
+		return -ENODEV;
+	}
+
 	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
 	if (!wdt)
 		return -ENOMEM;
@@ -172,6 +209,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
 	wdt->wdd.min_timeout = 1;
 	wdt->wdd.max_timeout = 0x10000000U / wdt->rate;
 	wdt->wdd.parent = &pdev->dev;
+	wdt->layout = match->data;
 
 	if (readl(wdt->base + WDT_STS) & 1)
 		wdt->wdd.bootstatus = WDIOF_CARDRESET;
@@ -207,13 +245,6 @@ static int qcom_wdt_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id qcom_wdt_of_table[] = {
-	{ .compatible = "qcom,kpss-timer" },
-	{ .compatible = "qcom,scss-timer" },
-	{ },
-};
-MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
-
 static struct platform_driver qcom_watchdog_driver = {
 	.probe	= qcom_wdt_probe,
 	.remove	= qcom_wdt_remove,
-- 
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