1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <string.h>
18 #include <stdio.h>
19 #include <stdint.h>
20 #include <termios.h>
21 #include <unistd.h>
22 #include <sys/fcntl.h>
23 #include <sys/ioctl.h>
24 #include <linux/i2c-dev.h>
25
26 #include "stm32_bl.h"
27 #include "uart.h"
28
uart_write_data(handle_t * handle,uint8_t * buffer,int length)29 uint8_t uart_write_data(handle_t *handle, uint8_t *buffer, int length)
30 {
31 uart_handle_t *uart_handle = (uart_handle_t *)handle;
32
33 buffer[length] = checksum(handle, buffer, length);
34
35 if (write(uart_handle->fd, buffer, length + 1) == (length + 1))
36 return CMD_ACK;
37 else
38 return CMD_NACK;
39 }
40
uart_write_cmd(handle_t * handle,uint8_t cmd)41 uint8_t uart_write_cmd(handle_t *handle, uint8_t cmd)
42 {
43 uart_handle_t *uart_handle = (uart_handle_t *)handle;
44 uint8_t buffer[2 * sizeof(uint8_t)] = { cmd, ~cmd };
45 int length = 2 * sizeof(uint8_t);
46
47 if (cmd == CMD_UART_ENABLE)
48 length--;
49
50 if (write(uart_handle->fd, buffer, length) == length)
51 return CMD_ACK;
52 else
53 return CMD_NACK;
54 }
55
uart_read_data(handle_t * handle,uint8_t * data,int length)56 uint8_t uart_read_data(handle_t *handle, uint8_t *data, int length)
57 {
58 uart_handle_t *uart_handle = (uart_handle_t *)handle;
59 int ret;
60
61 while (length > 0) {
62 ret = read(uart_handle->fd, data, length);
63 if (ret <= 0)
64 return CMD_NACK;
65 data += ret;
66 length -= ret;
67 }
68
69 return CMD_ACK;
70 }
71
uart_read_ack(handle_t * handle)72 uint8_t uart_read_ack(handle_t *handle)
73 {
74 uint8_t buffer;
75
76 if (handle->read_data(handle, &buffer, sizeof(uint8_t)) == CMD_ACK)
77 return buffer;
78 else
79 return CMD_BUSY;
80 }
81
uart_init(handle_t * handle)82 int uart_init(handle_t *handle)
83 {
84 uart_handle_t *uart_handle = (uart_handle_t *)handle;
85 struct termios tio;
86 int fl;
87
88 handle->cmd_erase = CMD_ERASE;
89 handle->cmd_read_memory = CMD_READ_MEMORY;
90 handle->cmd_write_memory = CMD_WRITE_MEMORY;
91
92 handle->no_extra_sync = 1;
93
94 handle->write_data = uart_write_data;
95 handle->write_cmd = uart_write_cmd;
96 handle->read_data = uart_read_data;
97 handle->read_ack = uart_read_ack;
98
99 /* then switch the fd to blocking */
100 fl = fcntl(uart_handle->fd, F_GETFL, 0);
101 if (fl < 0)
102 return fl;
103 fl = fcntl(uart_handle->fd, F_SETFL, fl & ~O_NDELAY);
104 if (fl < 0)
105 return fl;
106 if (tcgetattr(uart_handle->fd, &tio))
107 memset(&tio, 0, sizeof(tio));
108
109 tio.c_cflag = CS8 | CLOCAL | CREAD | PARENB;
110 cfsetospeed(&tio, B57600);
111 cfsetispeed(&tio, B57600);
112 tio.c_iflag = 0; /* turn off IGNPAR */
113 tio.c_oflag = 0; /* turn off OPOST */
114 tio.c_lflag = 0; /* turn off CANON, ECHO*, etc */
115 tio.c_cc[VTIME] = 5;
116 tio.c_cc[VMIN] = 0;
117 tcflush(uart_handle->fd, TCIFLUSH);
118 tcsetattr(uart_handle->fd, TCSANOW, &tio);
119
120 /* Init USART */
121 uart_write_cmd(handle, CMD_UART_ENABLE);
122 if (uart_read_ack(handle) == CMD_ACK)
123 return 0;
124
125 return -1;
126 }
127