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fix(uart): eliminated potential glitch on TX at setup if TX signal is inversed

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Closes https://github.com/espressif/esp-idf/issues/14285
This commit is contained in:
Song Ruo Jing
2024-08-12 21:50:18 +08:00
parent b600a2ef8b
commit 5dd2f38eb4
1 changed files with 6 additions and 5 deletions
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11
components/driver/uart/uart.c
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@@ -743,16 +743,17 @@ esp_err_t uart_set_pin(uart_port_t uart_num, int tx_io_num, int rx_io_num, int r
if (tx_io_num >= 0 && !uart_try_set_iomux_pin(uart_num, tx_io_num, SOC_UART_TX_PIN_IDX)) {
if (uart_num < SOC_UART_HP_NUM) {
gpio_hal_iomux_func_sel(GPIO_PIN_MUX_REG[tx_io_num], PIN_FUNC_GPIO);
gpio_set_level(tx_io_num, 1);
esp_rom_gpio_connect_out_signal(tx_io_num, UART_PERIPH_SIGNAL(uart_num, SOC_UART_TX_PIN_IDX), 0, 0);
// output enable is set inside esp_rom_gpio_connect_out_signal func after the signal is connected
// (output enabled too early may cause unnecessary level change at the pad)
}
#if SOC_LP_GPIO_MATRIX_SUPPORTED
else {
rtc_gpio_set_direction(tx_io_num, RTC_GPIO_MODE_OUTPUT_ONLY);
rtc_gpio_init(tx_io_num);
rtc_gpio_iomux_func_sel(tx_io_num, 1);
lp_gpio_connect_out_signal(tx_io_num, UART_PERIPH_SIGNAL(uart_num, SOC_UART_TX_PIN_IDX), 0, 0);
// output enable is set inside lp_gpio_connect_out_signal func after the signal is connected
}
#endif
}
@@ -760,7 +761,7 @@ esp_err_t uart_set_pin(uart_port_t uart_num, int tx_io_num, int rx_io_num, int r
if (rx_io_num >= 0 && !uart_try_set_iomux_pin(uart_num, rx_io_num, SOC_UART_RX_PIN_IDX)) {
if (uart_num < SOC_UART_HP_NUM) {
gpio_hal_iomux_func_sel(GPIO_PIN_MUX_REG[rx_io_num], PIN_FUNC_GPIO);
gpio_set_pull_mode(rx_io_num, GPIO_PULLUP_ONLY);
gpio_set_pull_mode(rx_io_num, GPIO_PULLUP_ONLY); // This does not consider that RX signal can be read inverted by configuring the hardware (i.e. idle is at low level). However, it is only a weak pullup, the TX at the other end can always drive the line.
gpio_set_direction(rx_io_num, GPIO_MODE_INPUT);
esp_rom_gpio_connect_in_signal(rx_io_num, UART_PERIPH_SIGNAL(uart_num, SOC_UART_RX_PIN_IDX), 0);
}
@@ -778,15 +779,15 @@ esp_err_t uart_set_pin(uart_port_t uart_num, int tx_io_num, int rx_io_num, int r
if (rts_io_num >= 0 && !uart_try_set_iomux_pin(uart_num, rts_io_num, SOC_UART_RTS_PIN_IDX)) {
if (uart_num < SOC_UART_HP_NUM) {
gpio_hal_iomux_func_sel(GPIO_PIN_MUX_REG[rts_io_num], PIN_FUNC_GPIO);
gpio_set_direction(rts_io_num, GPIO_MODE_OUTPUT);
esp_rom_gpio_connect_out_signal(rts_io_num, UART_PERIPH_SIGNAL(uart_num, SOC_UART_RTS_PIN_IDX), 0, 0);
// output enable is set inside esp_rom_gpio_connect_out_signal func after the signal is connected
}
#if SOC_LP_GPIO_MATRIX_SUPPORTED
else {
rtc_gpio_set_direction(rts_io_num, RTC_GPIO_MODE_OUTPUT_ONLY);
rtc_gpio_init(rts_io_num);
rtc_gpio_iomux_func_sel(rts_io_num, 1);
lp_gpio_connect_out_signal(rts_io_num, UART_PERIPH_SIGNAL(uart_num, SOC_UART_RTS_PIN_IDX), 0, 0);
// output enable is set inside lp_gpio_connect_out_signal func after the signal is connected
}
#endif
}