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
|
#ifndef _ATARI_SCCSERIAL_H
#define _ATARI_SCCSERIAL_H
/* Special configuration ioctls for the Atari SCC5380 Serial
* Communications Controller
*/
/* ioctl command codes */
#define TIOCGATSCC 0x54c0 /* get SCC configuration */
#define TIOCSATSCC 0x54c1 /* set SCC configuration */
#define TIOCDATSCC 0x54c2 /* reset configuration to defaults */
/* Clock sources */
#define CLK_RTxC 0
#define CLK_TRxC 1
#define CLK_PCLK 2
/* baud_bases for the common clocks in the Atari. These are the real
* frequencies divided by 16.
*/
#define SCC_BAUD_BASE_TIMC 19200 /* 0.3072 MHz from TT-MFP, Timer C */
#define SCC_BAUD_BASE_BCLK 153600 /* 2.4576 MHz */
#define SCC_BAUD_BASE_PCLK4 229500 /* 3.6720 MHz */
#define SCC_BAUD_BASE_PCLK 503374 /* 8.0539763 MHz */
#define SCC_BAUD_BASE_NONE 0 /* for not connected or unused
* clock sources */
/* The SCC configuration structure */
struct atari_SCCserial {
unsigned RTxC_base; /* base_baud of RTxC */
unsigned TRxC_base; /* base_baud of TRxC */
unsigned PCLK_base; /* base_baud of PCLK, for both channels! */
struct {
unsigned clksrc; /* CLK_RTxC, CLK_TRxC or CLK_PCLK */
unsigned divisor; /* divisor for base baud, valid values:
* see below */
} baud_table[17]; /* For 50, 75, 110, 135, 150, 200, 300,
* 600, 1200, 1800, 2400, 4800, 9600,
* 19200, 38400, 57600 and 115200 bps. The
* last two could be replaced by other
* rates > 38400 if they're not possible.
*/
};
/* The following divisors are valid:
*
* - CLK_RTxC: 1 or even (1, 2 and 4 are the direct modes, > 4 use
* the BRG)
*
* - CLK_TRxC: 1, 2 or 4 (no BRG, only direct modes possible)
*
* - CLK_PCLK: >= 4 and even (no direct modes, only BRG)
*
*/
#endif /* _ATARI_SCCSERIAL_H */
|
