1 /*
2  * Copyright (c) 2006-2021, RT-Thread Development Team
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  *
6  * Change Logs:
7  * Date           Author       Notes
8  * 2018/5/5       Bernard      The first version
9  */
10 
11 #include <rthw.h>
12 #include <rtthread.h>
13 #include <rtdevice.h>
14 
15 #include "raspi.h"
16 #include "board.h"
17 #include "drv_uart.h"
18 
19 #define AUX_BASE            (0x3F000000 + 0x215000)
20 
21 struct hw_uart_device
22 {
23     rt_ubase_t hw_base;
24     rt_uint32_t irqno;
25 };
26 
uart_configure(struct rt_serial_device * serial,struct serial_configure * cfg)27 static rt_err_t uart_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
28 {
29     struct hw_uart_device *uart;
30 
31     RT_ASSERT(serial != RT_NULL);
32     uart = (struct hw_uart_device *)serial->parent.user_data;
33 
34     if (uart->hw_base == AUX_BASE)
35     {
36         rt_uint32_t value;
37 
38         /* GPIO function set */
39         value = BCM283X_GPIO_GPFSEL(1);
40         value &= ~(7 << 12); /* GPIO14 */
41         value |= 2 << 12 ; /* ALT5 */
42         value &= ~(7 << 15); /* GPIO15 */
43         value |= 2 << 15 ; /* ALT5 */
44         BCM283X_GPIO_GPFSEL(1) = value;
45 
46         BCM283X_GPIO_GPPUD = 0;
47         BCM283X_GPIO_GPPUDCLK(0) = (1 << 14) | (1 << 15);
48         BCM283X_GPIO_GPPUDCLK(0) = 0;
49 
50         AUX_ENABLES(uart->hw_base)      = 1;    /* Enable UART1 */
51         AUX_MU_IER_REG(uart->hw_base)   = 0;    /* Disable interrupt */
52         AUX_MU_CNTL_REG(uart->hw_base)  = 0;    /* Disable Transmitter and Receiver */
53         AUX_MU_LCR_REG(uart->hw_base)   = 3;    /* Works in 8-bit mode */
54         AUX_MU_MCR_REG(uart->hw_base)   = 0;    /* Disable RTS */
55         AUX_MU_IIR_REG(uart->hw_base)   = 0xC6; /* Enable FIFO, Clear FIFO */
56         AUX_MU_BAUD_REG(uart->hw_base)  = 270;  /* 115200 = system clock 250MHz / (8 * (baud + 1)), baud = 270 */
57         AUX_MU_CNTL_REG(uart->hw_base)  = 3;    /* Enable Transmitter and Receiver */
58     }
59 
60     return RT_EOK;
61 }
62 
uart_control(struct rt_serial_device * serial,int cmd,void * arg)63 static rt_err_t uart_control(struct rt_serial_device *serial, int cmd, void *arg)
64 {
65     struct hw_uart_device *uart;
66 
67     RT_ASSERT(serial != RT_NULL);
68     uart = (struct hw_uart_device *)serial->parent.user_data;
69 
70     switch (cmd)
71     {
72     case RT_DEVICE_CTRL_CLR_INT:
73         /* disable rx irq */
74         AUX_MU_IER_REG(uart->hw_base) = 0x0;
75         rt_hw_interrupt_mask(uart->irqno);
76         break;
77 
78     case RT_DEVICE_CTRL_SET_INT:
79         /* enable rx irq */
80         AUX_MU_IER_REG(uart->hw_base) = 0x1;
81         rt_hw_interrupt_umask(uart->irqno);
82         break;
83     }
84 
85     return RT_EOK;
86 }
87 
uart_putc(struct rt_serial_device * serial,char c)88 static int uart_putc(struct rt_serial_device *serial, char c)
89 {
90     struct hw_uart_device *uart;
91 
92     RT_ASSERT(serial != RT_NULL);
93     uart = (struct hw_uart_device *)serial->parent.user_data;
94 
95     while (!(AUX_MU_LSR_REG(uart->hw_base) & 0x20));
96     AUX_MU_IO_REG(uart->hw_base) = c;
97 
98     return 1;
99 }
100 
uart_getc(struct rt_serial_device * serial)101 static int uart_getc(struct rt_serial_device *serial)
102 {
103     int ch = -1;
104     struct hw_uart_device *uart;
105 
106     RT_ASSERT(serial != RT_NULL);
107     uart = (struct hw_uart_device *)serial->parent.user_data;
108 
109     if ((AUX_MU_LSR_REG(uart->hw_base) & 0x01))
110     {
111         ch = AUX_MU_IO_REG(uart->hw_base) & 0xff;
112     }
113 
114     return ch;
115 }
116 
117 static const struct rt_uart_ops _uart_ops =
118 {
119     uart_configure,
120     uart_control,
121     uart_putc,
122     uart_getc,
123 };
124 
rt_hw_uart_isr(int irqno,void * param)125 static void rt_hw_uart_isr(int irqno, void *param)
126 {
127     struct rt_serial_device *serial = (struct rt_serial_device*)param;
128     rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_IND);
129 }
130 
131 #ifdef RT_USING_UART0
132 /* UART device driver structure */
133 static struct hw_uart_device _uart0_device =
134 {
135     RPI_UART0_BASE,
136     IRQ_PBA8_UART0,
137 };
138 static struct rt_serial_device _serial0;
139 #endif
140 
141 #ifdef RT_USING_UART1
142 /* UART1 device driver structure */
143 static struct hw_uart_device _uart1_device =
144 {
145     AUX_BASE,
146     IRQ_AUX,
147 };
148 static struct rt_serial_device _serial1;
149 #endif
150 
rt_hw_uart_init(void)151 int rt_hw_uart_init(void)
152 {
153     struct hw_uart_device *uart;
154     struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
155 
156 #ifdef RT_USING_UART0
157     uart = &_uart0_device;
158 
159     _serial0.ops    = &_uart_ops;
160     _serial0.config = config;
161 
162     /* register UART1 device */
163     rt_hw_serial_register(&_serial0, "uart0",
164                           RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
165                           uart);
166     rt_hw_interrupt_install(uart->irqno, rt_hw_uart_isr, &_serial0, "uart0");
167 #endif
168 
169 #ifdef RT_USING_UART1
170     uart = &_uart1_device;
171     _serial1.ops = &_uart_ops;
172     _serial1.config = config;
173 
174     /* register UART1 device */
175     rt_hw_serial_register(&_serial1, "uart1",
176                           RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX, uart);
177     /* enable Rx and Tx of UART */
178     rt_hw_interrupt_install(uart->irqno, rt_hw_uart_isr, &_serial1, "uart1");
179 #endif
180 
181     return 0;
182 }
183