1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
// lpc176x serial port
//
// Copyright (C) 2018-2021 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include "board/armcm_boot.h" // armcm_enable_irq
#include "autoconf.h" // CONFIG_SERIAL_BAUD
#include "board/irq.h" // irq_save
#include "board/serial_irq.h" // serial_rx_data
#include "command.h" // DECL_CONSTANT_STR
#include "internal.h" // gpio_peripheral
#include "sched.h" // DECL_INIT
#if CONFIG_LPC_SERIAL_UART0_P03_P02
DECL_CONSTANT_STR("RESERVE_PINS_serial", "P0.3,P0.2");
#define GPIO_Rx GPIO(0, 3)
#define GPIO_Tx GPIO(0, 2)
#define GPIO_FUNCTION_UARTx 1
#define LPC_UARTx LPC_UART0
#define UARTx_IRQn UART0_IRQn
#define PCLK_UARTx PCLK_UART0
#elif CONFIG_LPC_SERIAL_UART3_P429_P428
DECL_CONSTANT_STR("RESERVE_PINS_serial", "P4.29,P4.28");
#define GPIO_Rx GPIO(4, 29)
#define GPIO_Tx GPIO(4, 28)
#define GPIO_FUNCTION_UARTx 3
#define LPC_UARTx LPC_UART3
#define UARTx_IRQn UART3_IRQn
#define PCLK_UARTx PCLK_UART3
#endif
// Write tx bytes to the serial port
static void
kick_tx(void)
{
for (;;) {
if (!(LPC_UARTx->LSR & (1<<5))) {
// Output fifo full - enable tx irq
LPC_UARTx->IER = 0x03;
break;
}
uint8_t data;
int ret = serial_get_tx_byte(&data);
if (ret) {
// No more data to send - disable tx irq
LPC_UARTx->IER = 0x01;
break;
}
LPC_UARTx->THR = data;
}
}
void
UARTx_IRQHandler(void)
{
uint32_t iir = LPC_UARTx->IIR, status = iir & 0x0f;
if (status == 0x04)
serial_rx_byte(LPC_UARTx->RBR);
else if (status == 0x02)
kick_tx();
}
void
serial_enable_tx_irq(void)
{
if (LPC_UARTx->LSR & (1<<5)) {
irqstatus_t flag = irq_save();
kick_tx();
irq_restore(flag);
}
}
void
serial_init(void)
{
// Setup baud
LPC_UARTx->LCR = (1<<7); // set DLAB bit
enable_pclock(PCLK_UARTx);
uint32_t pclk = get_pclock_frequency(PCLK_UARTx);
uint32_t div = pclk / (CONFIG_SERIAL_BAUD * 16);
LPC_UARTx->DLL = div & 0xff;
LPC_UARTx->DLM = (div >> 8) & 0xff;
LPC_UARTx->FDR = 0x10;
LPC_UARTx->LCR = 3; // 8N1 ; clear DLAB bit
// Enable fifo
LPC_UARTx->FCR = 0x01;
// Setup pins
gpio_peripheral(GPIO_Rx, GPIO_FUNCTION_UARTx, 0);
gpio_peripheral(GPIO_Tx, GPIO_FUNCTION_UARTx, 0);
// Enable receive irq
armcm_enable_irq(UARTx_IRQHandler, UARTx_IRQn, 0);
LPC_UARTx->IER = 0x01;
}
DECL_INIT(serial_init);
|
