blob: e5ddbd7cdf46a4c3486ef8b3c2c577c257d45fd4 (
plain)
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
|
/*
* NXP SC16IS740 SPI UART driver
*
* Copyright (C) 2012 Harald Welte <laforge@gnumonks.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 or
* (at your option) version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include "cc32_spi.h"
#define RHR 0x00
#define THR 0x00
#define IER 0x01
#define FCR 0x02
#define IIR 0x02
#define LCR 0x03
#define MCR 0x04
#define LSR 0x05
#define MSR 0x06
#define SPR 0x07
#define DLL RHR
#define DLH IER
#define EFR FCR
static void reg_write(uint8_t reg, uint8_t val)
{
uint8_t cmd = (reg << 3);
cc32_spi_ncs(0);
cc32_spi_xcv_byte(cmd);
cc32_spi_xcv_byte(val);
cc32_spi_ncs(1);
}
static int reg_read(uint8_t reg)
{
uint8_t tx = (reg << 3) | 0x80;
uint8_t ret;
cc32_spi_ncs(0);
cc32_spi_xcv_byte(tx);
ret = cc32_spi_xcv_byte(0);
cc32_spi_ncs(1);
return ret;
}
static void fifo_write(uint8_t *buf, uint8_t len)
{
uint8_t cmd = (0 << 3);
cc32_spi_ncs(0);
cc32_spi_xcv_byte(cmd);
while (len--)
cc32_spi_xcv_byte(*buf++);
cc32_spi_ncs(1);
}
static void fifo_read(uint8_t *buf, uint8_t len)
{
uint8_t cmd = (0 << 3) | 0x80;
cc32_spi_ncs(0);
cc32_spi_xcv_byte(cmd);
while (len--)
*(buf++) = cc32_spi_xcv_byte(0);
cc32_spi_ncs(1);
}
void uart_sc16is740_init()
{
/* set 8N1 */
reg_write(LCR, (3 << 0) | (0 << 2));
/* set LCR[7] = 1 (divisor latch) */
reg_write(LCR, reg_read(LCR) | 0x80);
/* baud rate generator for 115200 */
reg_write(DLL, 1);
reg_write(DLH, 0);
/* clear LCR[7] = 0 (divisor latch) */
reg_write(LCR, reg_read(LCR) & ~0x80);
}
void uart_sc16is740_putchar(uint8_t ch)
{
/* wait until THR empty */
while (!(reg_read(LSR) & (1 << 5))) { }
reg_write(THR, ch);
}
uint8_t uart_sc16is740_getchar(void)
{
do {
} while (!(reg_read(LSR) & 1));
return reg_read(THR);
}
|
