feat(st-reset): add stm32mp2_reset driver
This driver manages the resets of the peripherals embedded in STM32MP2.
Like clock driver, it also uses the RCC peripheral.
Change-Id: I8217891bdf1b847925aad77f3f6ef542f08d1fba
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/drivers/st/reset/stm32mp2_reset.c b/drivers/st/reset/stm32mp2_reset.c
new file mode 100644
index 0000000..0918df5
--- /dev/null
+++ b/drivers/st/reset/stm32mp2_reset.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2024, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <drivers/st/stm32mp_reset.h>
+#include <lib/mmio.h>
+#include <lib/utils_def.h>
+
+#include <platform_def.h>
+
+static uint32_t id2reg_offset(unsigned int reset_id)
+{
+ return ((reset_id & GENMASK(31, 5)) >> 5) * sizeof(uint32_t);
+}
+
+static uint8_t id2reg_bit_pos(unsigned int reset_id)
+{
+ return (uint8_t)(reset_id & GENMASK(4, 0));
+}
+
+static int reset_toggle(uint32_t id, unsigned int to_us, bool reset_status)
+{
+ uint32_t offset = id2reg_offset(id);
+ uint32_t bitmsk = BIT(id2reg_bit_pos(id));
+ uint32_t bit_check;
+ uintptr_t rcc_base = stm32mp_rcc_base();
+
+ if (reset_status) {
+ mmio_setbits_32(rcc_base + offset, bitmsk);
+ bit_check = bitmsk;
+ } else {
+ mmio_clrbits_32(rcc_base + offset, bitmsk);
+ bit_check = 0U;
+ }
+
+ if (to_us != 0U) {
+ uint64_t timeout_ref = timeout_init_us(to_us);
+
+ while ((mmio_read_32(rcc_base + offset) & bitmsk) != bit_check) {
+ if (timeout_elapsed(timeout_ref)) {
+ return -ETIMEDOUT;
+ }
+ }
+ }
+
+ return 0;
+}
+
+int stm32mp_reset_assert(uint32_t id, unsigned int to_us)
+{
+ return reset_toggle(id, to_us, true);
+}
+
+int stm32mp_reset_deassert(uint32_t id, unsigned int to_us)
+{
+ return reset_toggle(id, to_us, false);
+}
+
+void __dead2 stm32mp_system_reset(void)
+{
+ uintptr_t rcc_base = stm32mp_rcc_base();
+
+ mmio_setbits_32(rcc_base + RCC_GRSTCSETR, RCC_GRSTCSETR_SYSRST);
+
+ /* Loop in case system reset is not immediately caught */
+ while (true) {
+ wfi();
+ }
+}