stm32mp1: add watchdog support
Introduce driver for STM32 IWDG peripheral (Independent Watchdog).
It is configured according to device tree content and should be enabled
from there.
The watchdog is not started by default. It can be started after an HW
reset if the dedicated OTP is fused.
The watchdog also needs to be frozen if a debugger is attached.
This is done by configuring the correct bits in DBGMCU.
This configuration is allowed by checking BSEC properties.
An increase of BL2 size is also required when adding this new code.
Change-Id: Ide7535d717885ce2f9c387cf17afd8b5607f3e7f
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
diff --git a/plat/st/stm32mp1/stm32mp1_dbgmcu.c b/plat/st/stm32mp1/stm32mp1_dbgmcu.c
new file mode 100644
index 0000000..a614267
--- /dev/null
+++ b/plat/st/stm32mp1/stm32mp1_dbgmcu.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2016-2019, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+
+#include <platform_def.h>
+
+#include <common/debug.h>
+#include <drivers/st/bsec.h>
+#include <drivers/st/stm32mp1_rcc.h>
+#include <lib/mmio.h>
+#include <lib/utils_def.h>
+
+#include <stm32mp1_dbgmcu.h>
+
+#define DBGMCU_APB4FZ1 U(0x2C)
+#define DBGMCU_APB4FZ1_IWDG2 BIT(2)
+
+static uintptr_t get_rcc_base(void)
+{
+ /* This is called before stm32mp_rcc_base() is available */
+ return RCC_BASE;
+}
+
+static int stm32mp1_dbgmcu_init(void)
+{
+ uint32_t dbg_conf;
+ uintptr_t rcc_base = get_rcc_base();
+
+ dbg_conf = bsec_read_debug_conf();
+
+ if ((dbg_conf & BSEC_DBGSWGEN) == 0U) {
+ uint32_t result = bsec_write_debug_conf(dbg_conf |
+ BSEC_DBGSWGEN);
+
+ if (result != BSEC_OK) {
+ ERROR("Error enabling DBGSWGEN\n");
+ return -1;
+ }
+ }
+
+ mmio_setbits_32(rcc_base + RCC_DBGCFGR, RCC_DBGCFGR_DBGCKEN);
+
+ return 0;
+}
+
+int stm32mp1_dbgmcu_freeze_iwdg2(void)
+{
+ uint32_t dbg_conf;
+
+ if (stm32mp1_dbgmcu_init() != 0) {
+ return -EPERM;
+ }
+
+ dbg_conf = bsec_read_debug_conf();
+
+ if ((dbg_conf & (BSEC_SPIDEN | BSEC_SPINDEN)) != 0U) {
+ mmio_setbits_32(DBGMCU_BASE + DBGMCU_APB4FZ1,
+ DBGMCU_APB4FZ1_IWDG2);
+ }
+
+ return 0;
+}