fix(esp8266): fix UART output error when start up

Add UART system API to flush UART and wait until all characters are sent.

components/esp8266/CMakeLists.txt

@@ -37,6 +37,7 @@ else()
         "source/startup.c"
         "source/system_api.c"
         "source/task_wdt.c"
+        "source/rom.c"
         "driver/adc.c"
         "driver/gpio.c"
         "driver/hw_timer.c"

components/esp8266/include/rom/uart.h

@@ -47,22 +47,7 @@ extern "C" {
   * The function defined in ROM code has a bug, so we define the correct version
   * here for compatibility.
   */
-static inline void IRAM_ATTR uart_tx_wait_idle(uint8_t uart_no) {
+void uart_tx_wait_idle(uint8_t uart_no);
-    uint32_t tx_bytes;
-    uint32_t baudrate, byte_delay_us;
-    uart_dev_t *const UART[2] = {&uart0, &uart1};
-    uart_dev_t *const uart = UART[uart_no];
-    
-    baudrate = (UART_CLK_FREQ / (uart->clk_div.val & 0xFFFFF));
-    byte_delay_us = (uint32_t)(10000000 / baudrate);
-
-    do {
-        tx_bytes = uart->status.txfifo_cnt;
-        /* either tx count or state is non-zero */
-    } while (tx_bytes);
-
-    ets_delay_us(byte_delay_us);
-}
 
 /**
   * @brief Output a char to printf channel, wait until fifo not full.

components/esp8266/source/esp_sleep.c

@@ -22,9 +22,9 @@
 #include "freertos/task.h"
 #include "driver/soc.h"
 #include "esp8266/timer_struct.h"
-#include "esp8266/uart_struct.h"
 #include "esp8266/rom_functions.h"
 #include "driver/rtc.h"
+#include "rom/uart.h"
 
 #define FRC2_LOAD               (0x60000620)
 #define FRC2_COUNT              (0x60000624)
@@ -109,21 +109,6 @@ static inline void update_soc_clk(pm_soc_clk_t *clk, uint32_t us)
     }
 }
 
-static void esp_sleep_wait_uart_empty(int no)
-{
-    int filled = 0;
-    const uart_dev_t *uart = (no == 0 ? &uart0 : &uart1);
-
-    while (uart->status.txfifo_cnt)
-        filled = 1;
-
-    if (filled) {
-        const uint32_t us = 10000000 / (UART_CLK_FREQ / uart->clk_div.val);
-
-        ets_delay_us(us);
-    }
-}
-
 esp_err_t esp_sleep_enable_timer_wakeup(uint32_t time_in_us)
 {
     if (time_in_us <= MIN_SLEEP_US)
@@ -174,8 +159,8 @@ void esp_sleep_start(void)
         return ;
     }
 
-    esp_sleep_wait_uart_empty(0);
+    uart_tx_wait_idle(0);
-    esp_sleep_wait_uart_empty(1);
+    uart_tx_wait_idle(1);
 
     int slept = 0;
     pm_soc_clk_t clk;

components/esp8266/source/phy_init.c

@@ -17,6 +17,7 @@
 #include <string.h>
 
 #include "rom/ets_sys.h"
+#include "rom/uart.h"
 
 #include "esp_err.h"
 #include "esp_phy_init.h"
@@ -69,6 +70,11 @@ esp_err_t esp_phy_rf_init(const esp_phy_init_data_t* init_data, esp_phy_calibrat
     esp_err_t status = ESP_OK;
     uint8_t sta_mac[6];
     uint8_t *local_init_data = calloc(1, 256);
+#ifdef CONFIG_CONSOLE_UART_BAUDRATE
+    const uint32_t uart_baudrate = CONFIG_CONSOLE_UART_BAUDRATE;
+#else
+    const uint32_t uart_baudrate = 74880; // ROM default baudrate
+#endif
 
     memcpy(local_init_data, init_data->params, 128);
 
@@ -85,6 +91,16 @@ esp_err_t esp_phy_rf_init(const esp_phy_init_data_t* init_data, esp_phy_calibrat
 
     esp_efuse_mac_get_default(sta_mac);
 
+    /**
+     * The API "register_chipv6_phy" will modify the APB frequency to 80MHz,
+     * so UARTs must be flush here, then reconfigurate the UART frequency dividor
+     */
+    uart_tx_wait_idle(0);
+    uart_div_modify(0, UART_CLK_FREQ / uart_baudrate);
+
+    uart_tx_wait_idle(1);
+    uart_div_modify(1, UART_CLK_FREQ / uart_baudrate);
+
     int ret = register_chipv6_phy(local_init_data);
     if (ret) {
         ESP_LOGI(TAG, "phy register error, ret:%d", ret);

components/esp8266/source/rom.c

@@ -0,0 +1,33 @@
+// Copyright 2019-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "rom/uart.h"
+
+void uart_tx_wait_idle(uint8_t uart_no)
+{
+    uint32_t tx_bytes;
+    uint32_t baudrate, byte_delay_us;
+    uart_dev_t *const UART[2] = {&uart0, &uart1};
+    uart_dev_t *const uart = UART[uart_no];
+    
+    baudrate = (UART_CLK_FREQ / (uart->clk_div.val & 0xFFFFF));
+    byte_delay_us = (uint32_t)(10000000 / baudrate);
+
+    do {
+        tx_bytes = uart->status.txfifo_cnt;
+        /* either tx count or state is non-zero */
+    } while (tx_bytes);
+
+    ets_delay_us(byte_delay_us);
+}

components/esp8266/source/startup.c

@@ -30,7 +30,6 @@
 #include "internal/esp_wifi_internal.h"
 #include "internal/esp_system_internal.h"
 #include "esp8266/eagle_soc.h"
-#include "esp8266/uart_register.h"
 
 #include "FreeRTOS.h"
 #include "task.h"
@@ -63,19 +62,6 @@ static inline int should_load(uint32_t load_addr)
     return 1;
 }
 
-static inline void uart_init()
-{
-#ifdef CONFIG_CONSOLE_UART_BAUDRATE
-    const uint32_t uart_baudrate = CONFIG_CONSOLE_UART_BAUDRATE;
-#else
-    const uint32_t uart_baudrate = 74880; // ROM default baudrate
-#endif
-    while (READ_PERI_REG(UART_STATUS(0)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S));
-    while (READ_PERI_REG(UART_STATUS(1)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S));
-    uart_div_modify(0, UART_CLK_FREQ / uart_baudrate);
-    uart_div_modify(1, UART_CLK_FREQ / uart_baudrate);
-}
-
 static void user_init_entry(void *param)
 {
     void (**func)(void);
@@ -98,7 +84,6 @@ static void user_init_entry(void *param)
     assert(nvs_flash_init() == 0);
     assert(rtc_init() == 0);
     assert(mac_init() == 0);
-    uart_init();
     assert(base_gpio_init() == 0);
     esp_phy_load_cal_and_init(0);