feat(ppa): add sleep retention support for DMA2D and PPA

components/esp_driver_ppa/esp32s31/ppa_retention.c

@@ -0,0 +1,39 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdint.h>
+#include "ppa_priv.h"
+#include "soc/ppa_reg.h"
+
+/** PPA Registers to be saved during sleep retention
+ *
+ * For CLUT mem, we shall choose not to power down the CLUT mem domain; Otherwise, there are two blocks of memory that needs to be restored by writing to mem addr directly.
+ * Since PPA driver is operation based, most of the registers are configured per operation, so no need to save/restore.
+ *
+ * PPA_CLUT_CONF_REG,
+ * PPA_INT_ENA_REG,
+ * PPA_SR_MEM_PD_REG, PPA_REG_CONF_REG, PPA_SRAM_CTRL_REG,
+ * PPA_RGB2GRAY_REG
+ */
+#define PPA_RETENTION_REGS_CNT 6
+#define PPA_RETENTION_REGS_BASE PPA_CLUT_CONF_REG
+static const uint32_t ppa_regs_map[4] = {0x1800009, 0x9, 0x0, 0x0};
+static const regdma_entries_config_t ppa_regdma_entries[] = {
+    [0] = {
+        .config = REGDMA_LINK_ADDR_MAP_INIT(REGDMA_PPA_LINK(0x00),
+                                            PPA_RETENTION_REGS_BASE, PPA_RETENTION_REGS_BASE,
+                                            PPA_RETENTION_REGS_CNT, 0, 0,
+                                            ppa_regs_map[0], ppa_regs_map[1],
+                                            ppa_regs_map[2], ppa_regs_map[3]),
+        .owner = ENTRY(0) | ENTRY(2),
+    },
+};
+
+const ppa_retention_desc_t ppa_reg_retention_info = {
+    .module = SLEEP_RETENTION_MODULE_PPA,
+    .regdma_entry_array = ppa_regdma_entries,
+    .array_size = ARRAY_SIZE(ppa_regdma_entries),
+};