1 files changed, 115 insertions, 0 deletions
diff --git a/plat/mediatek/mt8173/drivers/wdt/wdt.c b/plat/mediatek/mt8173/drivers/wdt/wdt.c
new file mode 100644
index 0000000..40f57ee
--- /dev/null
+++ b/plat/mediatek/mt8173/drivers/wdt/wdt.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2020, Google LLC. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/debug.h>
+#include <lib/mmio.h>
+#include <mt8173_def.h>
+#include <plat_sip_calls.h>
+#include <lib/psci/psci.h>
+#include <smccc_helpers.h>
+#include <wdt.h>
+
+#define WDT_BASE		(RGU_BASE + 0)
+#define WDT_MODE		(WDT_BASE + 0x00)
+#define WDT_LENGTH		(WDT_BASE + 0x04)
+#define WDT_RESTART		(WDT_BASE + 0x08)
+#define WDT_SWRST		(WDT_BASE + 0x14)
+
+#define WDT_MODE_DUAL_MODE	0x40
+#define WDT_MODE_IRQ		0x8
+#define WDT_MODE_KEY		0x22000000
+#define WDT_MODE_EXTEN		0x4
+#define WDT_MODE_EN		0x1
+#define WDT_LENGTH_KEY		0x8
+#define WDT_RESTART_KEY		0x1971
+#define WDT_SWRST_KEY		0x1209
+
+
+#define WDT_MIN_TIMEOUT 1
+#define WDT_MAX_TIMEOUT 31
+
+enum smcwd_call {
+	SMCWD_INFO		= 0,
+	SMCWD_SET_TIMEOUT	= 1,
+	SMCWD_ENABLE		= 2,
+	SMCWD_PET		= 3,
+};
+
+static int wdt_enabled_before_suspend;
+
+/*
+ * We expect the WDT registers to be correctly initialized by BL2 firmware
+ * (which may be board specific), so we do not reinitialize them here.
+ */
+
+void wdt_trigger_reset(void)
+{
+	mmio_write_32(WDT_SWRST, WDT_SWRST_KEY);
+}
+
+void wdt_pet(void)
+{
+	mmio_write_32(WDT_RESTART, WDT_RESTART_KEY);
+}
+
+int wdt_set_timeout(uint32_t timeout)
+{
+	/* One tick here equals 512 32KHz ticks. 512 / 32000 * 125 / 2 = 1 */
+	uint32_t ticks = timeout * 125 / 2;
+
+	if (timeout < WDT_MIN_TIMEOUT || timeout > WDT_MAX_TIMEOUT)
+		return PSCI_E_INVALID_PARAMS;
+
+	mmio_write_32(WDT_LENGTH, ticks << 5 | WDT_LENGTH_KEY);
+
+	return PSCI_E_SUCCESS;
+}
+
+void wdt_set_enable(int enable)
+{
+	if (enable)
+		wdt_pet();
+	mmio_clrsetbits_32(WDT_MODE, WDT_MODE_EN,
+			   WDT_MODE_KEY | (enable ? WDT_MODE_EN : 0));
+}
+
+void wdt_suspend(void)
+{
+	wdt_enabled_before_suspend = mmio_read_32(WDT_MODE) & WDT_MODE_EN;
+	if (wdt_enabled_before_suspend)
+		wdt_set_enable(0);
+}
+
+void wdt_resume(void)
+{
+	if (wdt_enabled_before_suspend)
+		wdt_set_enable(1);
+}
+
+uint64_t wdt_smc_handler(uint32_t x1,
+			uint32_t x2,
+			void *handle)
+{
+	int ret;
+
+	switch (x1) {
+	case SMCWD_INFO:
+		SMC_RET3(handle, PSCI_E_SUCCESS,
+			 WDT_MIN_TIMEOUT, WDT_MAX_TIMEOUT);
+	case SMCWD_SET_TIMEOUT:
+		ret = wdt_set_timeout(x2);
+		SMC_RET1(handle, ret);
+	case SMCWD_ENABLE:
+		wdt_set_enable(x2 > 0);
+		SMC_RET1(handle, PSCI_E_SUCCESS);
+	case SMCWD_PET:
+		wdt_pet();
+		SMC_RET1(handle, PSCI_E_SUCCESS);
+	default:
+		ERROR("Unimplemented SMCWD call (%d)\n", x1);
+		SMC_RET1(handle, PSCI_E_NOT_SUPPORTED);
+	}
+}