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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/**
* @file
*
* @ingroup raspberrypi_usart
*
* @brief USART support.
*/
/*
* Copyright (c) 2013 Alan Cudmore
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
*
* http://www.rtems.com/license/LICENSE
*
*/
#include <libchip/sersupp.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <bsp/usart.h>
#include <bsp/raspberrypi.h>
static void usart_delay(uint32_t n)
{
volatile uint32_t i = 0;
for(i = 0; i < n; i++);
}
static rtems_vector_number usart_get_irq_number(const console_tbl *ct)
{
return ct->ulIntVector;
}
static uint32_t usart_get_baud(const console_tbl *ct)
{
return ct->ulClock;
}
static void usart_set_baud(int minor, int baud)
{
/*
** Nothing for now
*/
return;
}
static void usart_initialize(int minor)
{
unsigned int gpio_reg;
/*
** Program GPIO pins for UART 0
*/
gpio_reg = BCM2835_REG(BCM2835_GPIO_GPFSEL1);
gpio_reg &= ~(7<<12); /* gpio14 */
gpio_reg |= (4<<12); /* alt0 */
gpio_reg &= ~(7<<15); /* gpio15 */
gpio_reg |= (4<<15); /* alt0 */
BCM2835_REG(BCM2835_GPIO_GPFSEL1) = gpio_reg;
BCM2835_REG(BCM2835_GPIO_GPPUD) = 0;
usart_delay(150);
BCM2835_REG(BCM2835_GPIO_GPPUDCLK0) = (1<<14)|(1<<15);
usart_delay(150);
BCM2835_REG(BCM2835_GPIO_GPPUDCLK0) = 0;
/*
** Init the PL011 UART
*/
BCM2835_REG(BCM2835_UART0_CR) = 0;
BCM2835_REG(BCM2835_UART0_ICR) = 0x7FF;
BCM2835_REG(BCM2835_UART0_IMSC) = 0;
BCM2835_REG(BCM2835_UART0_IBRD) = 1;
BCM2835_REG(BCM2835_UART0_FBRD) = 40;
BCM2835_REG(BCM2835_UART0_LCRH) = 0x70;
BCM2835_REG(BCM2835_UART0_RSRECR) = 0;
BCM2835_REG(BCM2835_UART0_CR) = 0x301;
BCM2835_REG(BCM2835_UART0_IMSC) = BCM2835_UART0_IMSC_RX;
usart_set_baud(minor, 115000);
}
static int usart_first_open(int major, int minor, void *arg)
{
rtems_libio_open_close_args_t *oc = (rtems_libio_open_close_args_t *) arg;
struct rtems_termios_tty *tty = (struct rtems_termios_tty *) oc->iop->data1;
const console_tbl *ct = Console_Port_Tbl [minor];
console_data *cd = &Console_Port_Data [minor];
cd->termios_data = tty;
rtems_termios_set_initial_baud(tty, ct->ulClock);
return 0;
}
static int usart_last_close(int major, int minor, void *arg)
{
return 0;
}
static int usart_read_polled(int minor)
{
if (minor == 0)
{
if(((BCM2835_REG(BCM2835_UART0_FR)) & BCM2835_UART0_FR_RXFE) == 0)
{
return((BCM2835_REG(BCM2835_UART0_DR)) & 0xFF );
}
else
{
return -1;
}
}
else
{
printk("Unknown console minor number: %d\n", minor);
return -1;
}
}
static void usart_write_polled(int minor, char c)
{
while (1)
{
if ((BCM2835_REG(BCM2835_UART0_FR) & BCM2835_UART0_FR_TXFF) == 0) break;
}
BCM2835_REG(BCM2835_UART0_DR) = c;
}
static ssize_t usart_write_support_polled(
int minor,
const char *s,
size_t n
)
{
ssize_t i = 0;
for (i = 0; i < n; ++i)
{
usart_write_polled(minor, s [i]);
}
return n;
}
static int usart_set_attributes(int minor, const struct termios *term)
{
return -1;
}
const console_fns bcm2835_usart_fns = {
.deviceProbe = libchip_serial_default_probe,
.deviceFirstOpen = usart_first_open,
.deviceLastClose = usart_last_close,
.deviceRead = usart_read_polled,
.deviceWrite = usart_write_support_polled,
.deviceInitialize = usart_initialize,
.deviceWritePolled = usart_write_polled,
.deviceSetAttributes = usart_set_attributes,
.deviceOutputUsesInterrupts = false
};
|
