[PATCH v2 15/20] watchdog: s3c2410_wdt: Add support for Google tensor SoCs

[Peter Griffin <peter.griffin@linaro.org>]

This patch adds the compatibles and drvdata for the Google
gs101 & gs201 SoCs found in Pixel 6 and Pixel 7 phones. Similar
to Exynos850 it has two watchdog instances, one for each cluster
and has some control bits in PMU registers.

The watchdog IP found in gs101 SoCs also supports a few
additional bits/features in the WTCON register which we add
support for and an additional register detailed below.

dbgack-mask - Enables masking WDT interrupt and reset request
according to asserted DBGACK input

windowed-mode - Enabled Windowed watchdog mode

Windowed watchdog mode also has an additional register WTMINCNT.
If windowed watchdog is enabled and you reload WTCNT when the
value is greater than WTMINCNT, it prompts interrupt or reset
request as if the watchdog time has expired.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
---
 drivers/watchdog/s3c2410_wdt.c | 104 ++++++++++++++++++++++++++++++---
 1 file changed, 95 insertions(+), 9 deletions(-)

diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 0b4bd883ff28..08a775c01c57 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -31,12 +31,14 @@
 #define S3C2410_WTDAT		0x04
 #define S3C2410_WTCNT		0x08
 #define S3C2410_WTCLRINT	0x0c
-
+#define S3C2410_WTMINCNT	0x10
 #define S3C2410_WTCNT_MAXCNT	0xffff
 
-#define S3C2410_WTCON_RSTEN	(1 << 0)
-#define S3C2410_WTCON_INTEN	(1 << 2)
-#define S3C2410_WTCON_ENABLE	(1 << 5)
+#define S3C2410_WTCON_RSTEN		(1 << 0)
+#define S3C2410_WTCON_INTEN		(1 << 2)
+#define S3C2410_WTCON_ENABLE		(1 << 5)
+#define S3C2410_WTCON_DBGACK_MASK	(1 << 16)
+#define S3C2410_WTCON_WINDOWED_WD	(1 << 20)
 
 #define S3C2410_WTCON_DIV16	(0 << 3)
 #define S3C2410_WTCON_DIV32	(1 << 3)
@@ -67,6 +69,12 @@
 #define EXYNOSAUTOV9_CLUSTER0_WDTRESET_BIT	25
 #define EXYNOSAUTOV9_CLUSTER1_WDTRESET_BIT	24
 
+#define GS_CLUSTER0_NONCPU_OUT			0x1220
+#define GS_CLUSTER1_NONCPU_OUT			0x1420
+#define GS_CLUSTER0_NONCPU_INT_EN		0x1244
+#define GS_CLUSTER1_NONCPU_INT_EN		0x1444
+#define GS_CLUSTER2_NONCPU_INT_EN		0x1644
+#define GS_RST_STAT_REG_OFFSET			0x3B44
 /**
  * DOC: Quirk flags for different Samsung watchdog IP-cores
  *
@@ -106,6 +114,8 @@
 #define QUIRK_HAS_PMU_RST_STAT			(1 << 2)
 #define QUIRK_HAS_PMU_AUTO_DISABLE		(1 << 3)
 #define QUIRK_HAS_PMU_CNT_EN			(1 << 4)
+#define QUIRK_HAS_DBGACK_BIT			(1 << 5)
+#define QUIRK_HAS_WTMINCNT_REG			(1 << 6)
 
 /* These quirks require that we have a PMU register map */
 #define QUIRKS_HAVE_PMUREG \
@@ -263,6 +273,54 @@ static const struct s3c2410_wdt_variant drv_data_exynosautov9_cl1 = {
 		  QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
 };
 
+static const struct s3c2410_wdt_variant drv_data_gs101_cl0 = {
+	.mask_reset_reg = GS_CLUSTER0_NONCPU_INT_EN,
+	.mask_bit = 2,
+	.mask_reset_inv = true,
+	.rst_stat_reg = GS_RST_STAT_REG_OFFSET,
+	.rst_stat_bit = 0,
+	.cnt_en_reg = GS_CLUSTER0_NONCPU_OUT,
+	.cnt_en_bit = 8,
+	.quirks = QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_CNT_EN |
+		  QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_DBGACK_BIT | QUIRK_HAS_WTMINCNT_REG,
+};
+
+static const struct s3c2410_wdt_variant drv_data_gs101_cl1 = {
+	.mask_reset_reg = GS_CLUSTER1_NONCPU_INT_EN,
+	.mask_bit = 2,
+	.mask_reset_inv = true,
+	.rst_stat_reg = GS_RST_STAT_REG_OFFSET,
+	.rst_stat_bit = 1,
+	.cnt_en_reg = GS_CLUSTER1_NONCPU_OUT,
+	.cnt_en_bit = 7,
+	.quirks = QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_CNT_EN |
+		  QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_DBGACK_BIT | QUIRK_HAS_WTMINCNT_REG,
+};
+
+static const struct s3c2410_wdt_variant drv_data_gs201_cl0 = {
+	.mask_reset_reg = GS_CLUSTER0_NONCPU_INT_EN,
+	.mask_bit = 2,
+	.mask_reset_inv = true,
+	.rst_stat_reg = GS_RST_STAT_REG_OFFSET,
+	.rst_stat_bit = 0,
+	.cnt_en_reg = GS_CLUSTER0_NONCPU_OUT,
+	.cnt_en_bit = 8,
+	.quirks = QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_CNT_EN |
+		  QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_DBGACK_BIT | QUIRK_HAS_WTMINCNT_REG,
+};
+
+static const struct s3c2410_wdt_variant drv_data_gs201_cl1 = {
+	.mask_reset_reg = GS_CLUSTER1_NONCPU_INT_EN,
+	.mask_bit = 2,
+	.mask_reset_inv = true,
+	.rst_stat_reg = GS_RST_STAT_REG_OFFSET,
+	.rst_stat_bit = 1,
+	.cnt_en_reg = GS_CLUSTER1_NONCPU_OUT,
+	.cnt_en_bit = 7,
+	.quirks = QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_CNT_EN |
+		  QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_DBGACK_BIT | QUIRK_HAS_WTMINCNT_REG,
+};
+
 static const struct of_device_id s3c2410_wdt_match[] = {
 	{ .compatible = "samsung,s3c2410-wdt",
 	  .data = &drv_data_s3c2410 },
@@ -278,6 +336,10 @@ static const struct of_device_id s3c2410_wdt_match[] = {
 	  .data = &drv_data_exynos850_cl0 },
 	{ .compatible = "samsung,exynosautov9-wdt",
 	  .data = &drv_data_exynosautov9_cl0 },
+	{ .compatible = "google,gs101-wdt",
+	  .data = &drv_data_gs101_cl0 },
+	{ .compatible = "google,gs201-wdt",
+	  .data = &drv_data_gs201_cl0 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
@@ -375,6 +437,21 @@ static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
 	return 0;
 }
 
+static void s3c2410wdt_mask_dbgack(struct s3c2410_wdt *wdt, bool mask)
+{
+	unsigned long wtcon;
+
+	if (!(wdt->drv_data->quirks & QUIRK_HAS_DBGACK_BIT))
+		return;
+
+	wtcon = readl(wdt->reg_base + S3C2410_WTCON);
+	if (mask)
+		wtcon |= S3C2410_WTCON_DBGACK_MASK;
+	else
+		wtcon &= ~S3C2410_WTCON_DBGACK_MASK;
+	writel(wtcon, wdt->reg_base + S3C2410_WTCON);
+}
+
 static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
 {
 	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
@@ -585,9 +662,11 @@ s3c2410_get_wdt_drv_data(struct platform_device *pdev, struct s3c2410_wdt *wdt)
 	}
 
 #ifdef CONFIG_OF
-	/* Choose Exynos850/ExynosAutov9 driver data w.r.t. cluster index */
+	/* Choose Exynos850/ExynosAutov9/gsx01 driver data w.r.t. cluster index */
 	if (variant == &drv_data_exynos850_cl0 ||
-	    variant == &drv_data_exynosautov9_cl0) {
+	    variant == &drv_data_exynosautov9_cl0 ||
+	    variant == &drv_data_gs101_cl0 ||
+	    variant == &drv_data_gs201_cl0) {
 		u32 index;
 		int err;
 
@@ -600,9 +679,14 @@ s3c2410_get_wdt_drv_data(struct platform_device *pdev, struct s3c2410_wdt *wdt)
 		case 0:
 			break;
 		case 1:
-			variant = (variant == &drv_data_exynos850_cl0) ?
-				&drv_data_exynos850_cl1 :
-				&drv_data_exynosautov9_cl1;
+			if (variant == &drv_data_exynos850_cl0)
+				variant = &drv_data_exynos850_cl1;
+			else if (variant == &drv_data_exynosautov9_cl0)
+				variant = &drv_data_exynosautov9_cl1;
+			else if (variant == &drv_data_gs101_cl0)
+				variant = &drv_data_gs101_cl1;
+			else if (variant == &drv_data_gs201_cl0)
+				variant = &drv_data_gs201_cl1;
 			break;
 		default:
 			return dev_err_probe(dev, -EINVAL, "wrong cluster index: %u\n", index);
@@ -700,6 +784,8 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 	wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 	wdt->wdt_device.parent = dev;
 
+	s3c2410wdt_mask_dbgack(wdt, true);
+
 	/*
 	 * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
 	 * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
-- 
2.42.0.609.gbb76f46606-goog