esp_rom: patch systimer driver for esp32c2

components/esp_rom/CMakeLists.txt

@@ -28,6 +28,10 @@ if(CONFIG_IDF_TARGET_ARCH_XTENSA)
     list(APPEND sources "patches/esp_rom_longjmp.S")
 endif()
 
+if(CONFIG_SOC_SYSTIMER_SUPPORTED)
+    list(APPEND sources "patches/esp_rom_systimer.c")
+endif()
+
 idf_component_register(SRCS ${sources}
                        INCLUDE_DIRS ${include_dirs}
                        PRIV_REQUIRES ${private_required_comp}

components/esp_rom/esp32c2/ld/esp32c2.rom.ld

@@ -211,20 +211,21 @@ PROVIDE( wdt_hal_handle_intr = 0x40000298 );
 PROVIDE( wdt_hal_feed = 0x4000029c );
 PROVIDE( wdt_hal_set_flashboot_en = 0x400002a0 );
 PROVIDE( wdt_hal_is_enabled = 0x400002a4 );
-PROVIDE( systimer_hal_init = 0x400002a8 );
 PROVIDE( systimer_hal_get_counter_value = 0x400002ac );
-PROVIDE( systimer_hal_get_time = 0x400002b0 );
-PROVIDE( systimer_hal_set_alarm_target = 0x400002b4 );
-PROVIDE( systimer_hal_set_alarm_period = 0x400002b8 );
 PROVIDE( systimer_hal_get_alarm_value = 0x400002bc );
 PROVIDE( systimer_hal_enable_alarm_int = 0x400002c0 );
-PROVIDE( systimer_hal_on_apb_freq_update = 0x400002c4 );
-PROVIDE( systimer_hal_counter_value_advance = 0x400002c8 );
 PROVIDE( systimer_hal_enable_counter = 0x400002cc );
 PROVIDE( systimer_hal_select_alarm_mode = 0x400002d0 );
 PROVIDE( systimer_hal_connect_alarm_counter = 0x400002d4 );
 PROVIDE( systimer_hal_counter_can_stall_by_cpu = 0x400002d8 );
 
+/* The following ROM functions are commented out because they're patched in the esp_rom_systimer.c */
+/* PROVIDE( systimer_hal_init = 0x400002a8 ); */
+/* PROVIDE( systimer_hal_get_time = 0x400002b0 ); */
+/* PROVIDE( systimer_hal_set_alarm_target = 0x400002b4 ); */
+/* PROVIDE( systimer_hal_set_alarm_period = 0x400002b8 ); */
+/* PROVIDE( systimer_hal_counter_value_advance = 0x400002c8 ); */
+
 
 /***************************************
  Group heap

components/esp_rom/linker.lf

@@ -3,3 +3,5 @@ archive: libesp_rom.a
 entries:
     esp_rom_spiflash (noflash)
     esp_rom_regi2c (noflash)
+    if SOC_SYSTIMER_SUPPORTED = y:
+        esp_rom_systimer (noflash)

components/esp_rom/patches/esp_rom_systimer.c

@@ -0,0 +1,67 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "sdkconfig.h"
+#include <stddef.h>
+#include "hal/systimer_hal.h"
+#include "hal/systimer_ll.h"
+
+#if CONFIG_HAL_SYSTIMER_USE_ROM_IMPL
+
+#if CONFIG_IDF_TARGET_ESP32C2
+void systimer_hal_init(systimer_hal_context_t *hal)
+{
+    hal->dev = &SYSTIMER;
+    systimer_ll_enable_clock(hal->dev, true);
+}
+
+void systimer_hal_deinit(systimer_hal_context_t *hal)
+{
+    systimer_ll_enable_clock(hal->dev, false);
+    hal->dev = NULL;
+}
+
+void systimer_hal_set_tick_rate_ops(systimer_hal_context_t *hal, systimer_hal_tick_rate_ops_t *ops)
+{
+    hal->ticks_to_us = ops->ticks_to_us;
+    hal->us_to_ticks = ops->us_to_ticks;
+}
+
+uint64_t systimer_hal_get_time(systimer_hal_context_t *hal, uint32_t counter_id)
+{
+    return hal->ticks_to_us(systimer_hal_get_counter_value(hal, counter_id));
+}
+
+void systimer_hal_set_alarm_target(systimer_hal_context_t *hal, uint32_t alarm_id, uint64_t target)
+{
+    systimer_counter_value_t alarm = {
+        .val = hal->us_to_ticks(target),
+    };
+    systimer_ll_enable_alarm(hal->dev, alarm_id, false);
+    systimer_ll_set_alarm_target(hal->dev, alarm_id, alarm.val);
+    systimer_ll_apply_alarm_value(hal->dev, alarm_id);
+    systimer_ll_enable_alarm(hal->dev, alarm_id, true);
+}
+
+void systimer_hal_set_alarm_period(systimer_hal_context_t *hal, uint32_t alarm_id, uint32_t period)
+{
+    systimer_ll_enable_alarm(hal->dev, alarm_id, false);
+    systimer_ll_set_alarm_period(hal->dev, alarm_id, hal->us_to_ticks(period));
+    systimer_ll_apply_alarm_value(hal->dev, alarm_id);
+    systimer_ll_enable_alarm(hal->dev, alarm_id, true);
+}
+
+void systimer_hal_counter_value_advance(systimer_hal_context_t *hal, uint32_t counter_id, int64_t time_us)
+{
+    systimer_counter_value_t new_count = {
+        .val = systimer_hal_get_counter_value(hal, counter_id) + hal->us_to_ticks(time_us),
+    };
+    systimer_ll_set_counter_value(hal->dev, counter_id, new_count.val);
+    systimer_ll_apply_counter_value(hal->dev, counter_id);
+}
+#endif // CONFIG_IDF_TARGET_ESP32C2
+
+#endif // CONFIG_HAL_SYSTIMER_USE_ROM_IMPL

components/hal/Kconfig

@@ -67,7 +67,7 @@ menu "Hardware Abstraction Layer (HAL) and Low Level (LL)"
 
     config HAL_SYSTIMER_USE_ROM_IMPL
         bool "Use ROM implementation of SysTimer HAL driver"
-        depends on ESP_ROM_HAS_HAL_SYSTIMER && !ESP32C2_XTAL_FREQ_26
+        depends on ESP_ROM_HAS_HAL_SYSTIMER
         default y
         help
             Enable this flag to use HAL functions from ROM instead of ESP-IDF.