1 /*
2  * serial.c UART driver
3  * Copyright (c) 2006-2021, RT-Thread Development Team
4  *
5  * SPDX-License-Identifier: Apache-2.0
6  *
7  * Change Logs:
8  * Date           Author       Notes
9  * 2013-03-30     Bernard      the first verion
10  */
11 
12 #include <rthw.h>
13 #include <rtdevice.h>
14 
15 #include "board.h"
16 #include "mmu.h"
17 
18 struct hw_uart_device
19 {
20     rt_size_t hw_base;
21     rt_size_t irqno;
22 };
23 
24 #define UART_DR(base)   __REG32(base + 0x00)
25 #define UART_FR(base)   __REG32(base + 0x18)
26 #define UART_CR(base)   __REG32(base + 0x30)
27 #define UART_IMSC(base) __REG32(base + 0x38)
28 #define UART_ICR(base)  __REG32(base + 0x44)
29 
30 #define UARTFR_RXFE     0x10
31 #define UARTFR_TXFF     0x20
32 #define UARTIMSC_RXIM   0x10
33 #define UARTIMSC_TXIM   0x20
34 #define UARTICR_RXIC    0x10
35 #define UARTICR_TXIC    0x20
36 
rt_hw_uart_isr(int irqno,void * param)37 static void rt_hw_uart_isr(int irqno, void *param)
38 {
39     struct rt_serial_device *serial = (struct rt_serial_device *)param;
40 
41     rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_IND);
42 }
43 
uart_configure(struct rt_serial_device * serial,struct serial_configure * cfg)44 static rt_err_t uart_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
45 {
46     return RT_EOK;
47 }
48 
uart_control(struct rt_serial_device * serial,int cmd,void * arg)49 static rt_err_t uart_control(struct rt_serial_device *serial, int cmd, void *arg)
50 {
51     struct hw_uart_device *uart;
52 
53     RT_ASSERT(serial != RT_NULL);
54     uart = (struct hw_uart_device *)serial->parent.user_data;
55 
56     switch (cmd)
57     {
58     case RT_DEVICE_CTRL_CLR_INT:
59         /* disable rx irq */
60         UART_IMSC(uart->hw_base) &= ~UARTIMSC_RXIM;
61         break;
62 
63     case RT_DEVICE_CTRL_SET_INT:
64         /* enable rx irq */
65         UART_IMSC(uart->hw_base) |= UARTIMSC_RXIM;
66         rt_hw_interrupt_umask(uart->irqno);
67         break;
68 
69     default:
70         return -1;
71     }
72 
73     return RT_EOK;
74 }
75 
uart_putc(struct rt_serial_device * serial,char c)76 static int uart_putc(struct rt_serial_device *serial, char c)
77 {
78     struct hw_uart_device *uart;
79 
80     RT_ASSERT(serial != RT_NULL);
81     uart = (struct hw_uart_device *)serial->parent.user_data;
82 
83     while (UART_FR(uart->hw_base) & UARTFR_TXFF);
84     UART_DR(uart->hw_base) = c;
85 
86     return 1;
87 }
88 
uart_getc(struct rt_serial_device * serial)89 static int uart_getc(struct rt_serial_device *serial)
90 {
91     int ch;
92     struct hw_uart_device *uart;
93 
94     RT_ASSERT(serial != RT_NULL);
95     uart = (struct hw_uart_device *)serial->parent.user_data;
96 
97     ch = -1;
98     if (!(UART_FR(uart->hw_base) & UARTFR_RXFE))
99     {
100         ch = UART_DR(uart->hw_base) & 0xff;
101     }
102 
103     return ch;
104 }
105 
106 static const struct rt_uart_ops _uart_ops =
107 {
108     uart_configure,
109     uart_control,
110     uart_putc,
111     uart_getc,
112 };
113 
114 #ifdef RT_USING_UART0
115 /* UART device driver structure */
116 static struct hw_uart_device _uart0_device =
117 {
118     PL011_UART0_BASE,
119     PL011_UART0_IRQNUM,
120 };
121 static struct rt_serial_device _serial0;
122 #endif
123 
rt_hw_uart_init(void)124 int rt_hw_uart_init(void)
125 {
126     struct hw_uart_device *uart;
127     struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
128 
129 #ifdef RT_USING_UART0
130     _uart0_device.hw_base = (rt_size_t)rt_ioremap((void*)_uart0_device.hw_base, PL011_UART0_SIZE);
131     uart = &_uart0_device;
132 
133     _serial0.ops    = &_uart_ops;
134     _serial0.config = config;
135 
136     /* register UART1 device */
137     rt_hw_serial_register(&_serial0, "uart0",
138                           RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
139                           uart);
140     rt_hw_interrupt_install(uart->irqno, rt_hw_uart_isr, &_serial0, "uart0");
141     /* enable Rx and Tx of UART */
142     UART_CR(uart->hw_base) = (1 << 0) | (1 << 8) | (1 << 9);
143 #endif
144 
145     return 0;
146 }
147