1 | /** |
---|
2 | * @file |
---|
3 | * |
---|
4 | * @ingroup mpc55xx |
---|
5 | * |
---|
6 | * @brief Enhanced Modular Input Output Subsystem (eMIOS). |
---|
7 | */ |
---|
8 | |
---|
9 | /* |
---|
10 | * Copyright (c) 2009 |
---|
11 | * embedded brains GmbH |
---|
12 | * Obere Lagerstr. 30 |
---|
13 | * D-82178 Puchheim |
---|
14 | * Germany |
---|
15 | * <rtems@embedded-brains.de> |
---|
16 | * |
---|
17 | * The license and distribution terms for this file may be |
---|
18 | * found in the file LICENSE in this distribution or at |
---|
19 | * http://www.rtems.com/license/LICENSE. |
---|
20 | */ |
---|
21 | |
---|
22 | #include <mpc55xx/regs.h> |
---|
23 | #include <mpc55xx/emios.h> |
---|
24 | #include <mpc55xx/mpc55xx.h> |
---|
25 | |
---|
26 | #include <bsp/irq.h> |
---|
27 | #include <bsp/utility.h> |
---|
28 | |
---|
29 | #define RTEMS_STATUS_CHECKS_USE_PRINTK |
---|
30 | |
---|
31 | #include <rtems/status-checks.h> |
---|
32 | |
---|
33 | /** |
---|
34 | * @brief Initialize the eMIOS module. |
---|
35 | * |
---|
36 | * The module is enabled. It is configured to use the internal clock. The |
---|
37 | * global prescaler value is set to @a prescaler. If the value is greater than |
---|
38 | * the maximum the maxium value will be used instead. A prescaler value of |
---|
39 | * zero disables the clock. |
---|
40 | * |
---|
41 | * @note No protection against concurrent execution. |
---|
42 | */ |
---|
43 | void mpc55xx_emios_initialize( unsigned prescaler) |
---|
44 | { |
---|
45 | union EMIOS_MCR_tag mcr = MPC55XX_ZERO_FLAGS; |
---|
46 | |
---|
47 | /* Enable module */ |
---|
48 | mcr.B.MDIS = 0; |
---|
49 | |
---|
50 | /* Disable debug mode */ |
---|
51 | mcr.B.FRZ = 1; |
---|
52 | |
---|
53 | /* Enable global time base */ |
---|
54 | mcr.B.GTBE = 1; |
---|
55 | |
---|
56 | /* Disable global prescaler (= disable clock) */ |
---|
57 | mcr.B.GPREN = 0; |
---|
58 | |
---|
59 | /* Set MCR */ |
---|
60 | EMIOS.MCR.R = mcr.R; |
---|
61 | |
---|
62 | /* Set OUDR */ |
---|
63 | EMIOS.OUDR.R = 0; |
---|
64 | |
---|
65 | /* Set global prescaler value */ |
---|
66 | mpc55xx_emios_set_global_prescaler( prescaler); |
---|
67 | } |
---|
68 | |
---|
69 | /** |
---|
70 | * @brief Returns the global prescaler value of the eMIOS module. |
---|
71 | */ |
---|
72 | unsigned mpc55xx_emios_global_prescaler( void) |
---|
73 | { |
---|
74 | union EMIOS_MCR_tag mcr = EMIOS.MCR; |
---|
75 | |
---|
76 | if (mcr.B.GPREN != 0) { |
---|
77 | return mcr.B.GPRE + 1; |
---|
78 | } else { |
---|
79 | return 0; |
---|
80 | } |
---|
81 | } |
---|
82 | |
---|
83 | /** |
---|
84 | * @brief Sets the global prescaler value of the eMIOS module. |
---|
85 | * |
---|
86 | * The global prescaler value is set to @a prescaler. If the value is greater |
---|
87 | * than the maximum the maxium value will be used instead. A prescaler value |
---|
88 | * of zero disables the clock. |
---|
89 | * |
---|
90 | * @note No protection against concurrent execution. |
---|
91 | */ |
---|
92 | void mpc55xx_emios_set_global_prescaler( unsigned prescaler) |
---|
93 | { |
---|
94 | union EMIOS_MCR_tag mcr = EMIOS.MCR; |
---|
95 | |
---|
96 | /* Enable or disable the global prescaler */ |
---|
97 | mcr.B.GPREN = prescaler > 0 ? 1 : 0; |
---|
98 | |
---|
99 | /* Set global prescaler value */ |
---|
100 | if (prescaler > 256) { |
---|
101 | prescaler = 256; |
---|
102 | } else if (prescaler < 1) { |
---|
103 | prescaler = 1; |
---|
104 | } |
---|
105 | mcr.B.GPRE = prescaler - 1; |
---|
106 | |
---|
107 | /* Set MCR */ |
---|
108 | EMIOS.MCR.R = mcr.R; |
---|
109 | } |
---|