Crash_Override/pico-uart-bridge
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uart-bridge: add HW flow control

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Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
This commit is contained in:
Álvaro Fernández Rojas 2022-05-03 15:05:37 +02:00
parent 05e4815f6b
commit f64b2ace58
2 changed files with 36 additions and 7 deletions
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16
README.md
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@ -11,9 +11,13 @@ This software is provided without warranty, according to the MIT License, and sh
Raspberry Pi Pico Pinout
------------------------
| Raspberry Pi Pico GPIO | Function |
|:----------------------:|:--------:|
| GPIO0 (Pin 1) | UART0 TX |
| GPIO1 (Pin 2) | UART0 RX |
| GPIO4 (Pin 6) | UART1 TX |
| GPIO5 (Pin 7) | UART1 RX |
| Raspberry Pi Pico GPIO | Function |
|:----------------------:|:---------:|
| GPIO0 (Pin 1) | UART0 TX |
| GPIO1 (Pin 2) | UART0 RX |
| GPIO2 (Pin 4) | UART0 CTS |
| GPIO3 (Pin 5) | UART0 RTS |
| GPIO4 (Pin 6) | UART1 TX |
| GPIO5 (Pin 7) | UART1 RX |
| GPIO6 (Pin 9) | UART1 CTS |
| GPIO7 (Pin 10) | UART1 RTS |

27
uart-bridge.c
View file

@ -11,6 +11,10 @@
#include <string.h>
#include <tusb.h>
#if !defined(BIT)
#define BIT(a) (1 << a)
#endif /* BIT */
#if !defined(MIN)
#define MIN(a, b) ((a > b) ? b : a)
#endif /* MIN */
@ -19,19 +23,26 @@
#define BUFFER_SIZE 256
#define DEF_HW_FLOW false
#define DEF_BIT_RATE 115200
#define DEF_STOP_BITS 1
#define DEF_PARITY 0
#define DEF_DATA_BITS 8
#define USB_LS_RTS BIT(1)
typedef struct {
uart_inst_t *const inst;
uint8_t tx_pin;
uint8_t rx_pin;
uint8_t cts_pin;
uint8_t rts_pin;
} uart_id_t;
typedef struct {
bool usb_hf;
cdc_line_coding_t usb_lc;
bool uart_hf;
cdc_line_coding_t uart_lc;
mutex_t lc_mtx;
uint8_t uart_buffer[BUFFER_SIZE];
@ -47,10 +58,14 @@ const uart_id_t UART_ID[CFG_TUD_CDC] = {
.inst = uart0,
.tx_pin = 0,
.rx_pin = 1,
.cts_pin = 2,
.rts_pin = 3,
}, {
.inst = uart1,
.tx_pin = 4,
.rx_pin = 5,
.cts_pin = 6,
.rts_pin = 7,
}
};
@ -99,6 +114,11 @@ void update_uart_cfg(uint8_t itf)
mutex_enter_blocking(&ud->lc_mtx);
if (ud->usb_hf != ud->uart_hf) {
uart_set_hw_flow(ui->inst, ud->usb_hf, ud->usb_hf);
ud->uart_hf = ud->usb_hf;
}
if (ud->usb_lc.bit_rate != ud->uart_lc.bit_rate) {
uart_set_baudrate(ui->inst, ud->usb_lc.bit_rate);
ud->uart_lc.bit_rate = ud->usb_lc.bit_rate;
@ -165,6 +185,7 @@ void usb_cdc_process(uint8_t itf)
uart_data_t *ud = &UART_DATA[itf];
mutex_enter_blocking(&ud->lc_mtx);
ud->usb_hf = !!(tud_cdc_n_get_line_state(itf) & USB_LS_RTS);
tud_cdc_n_get_line_coding(itf, &ud->usb_lc);
mutex_exit(&ud->lc_mtx);
@ -233,14 +254,18 @@ void init_uart_data(uint8_t itf) {
/* Pinmux */
gpio_set_function(ui->tx_pin, GPIO_FUNC_UART);
gpio_set_function(ui->rx_pin, GPIO_FUNC_UART);
gpio_set_function(ui->cts_pin, GPIO_FUNC_UART);
gpio_set_function(ui->rts_pin, GPIO_FUNC_UART);
/* USB CDC LC */
ud->usb_hf = DEF_HW_FLOW;
ud->usb_lc.bit_rate = DEF_BIT_RATE;
ud->usb_lc.data_bits = DEF_DATA_BITS;
ud->usb_lc.parity = DEF_PARITY;
ud->usb_lc.stop_bits = DEF_STOP_BITS;
/* UART LC */
ud->uart_hf = DEF_HW_FLOW;
ud->uart_lc.bit_rate = DEF_BIT_RATE;
ud->uart_lc.data_bits = DEF_DATA_BITS;
ud->uart_lc.parity = DEF_PARITY;
@ -257,7 +282,7 @@ void init_uart_data(uint8_t itf) {
/* UART start */
uart_init(ui->inst, ud->usb_lc.bit_rate);
uart_set_hw_flow(ui->inst, false, false);
uart_set_hw_flow(ui->inst, DEF_HW_FLOW, DEF_HW_FLOW);
uart_set_format(ui->inst, databits_usb2uart(ud->usb_lc.data_bits),
stopbits_usb2uart(ud->usb_lc.stop_bits),
parity_usb2uart(ud->usb_lc.parity));