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1 | /** @file\r | |
2 | UART Serial Port library functions\r | |
3 | \r | |
4 | Copyright (c) 2006 - 2009, Intel Corporation\r | |
5 | All rights reserved. This program and the accompanying materials\r | |
6 | are licensed and made available under the terms and conditions of the BSD License\r | |
7 | which accompanies this distribution. The full text of the license may be found at\r | |
8 | http://opensource.org/licenses/bsd-license.php\r | |
9 | \r | |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
12 | \r | |
13 | **/\r | |
14 | \r | |
15 | #include <Base.h>\r | |
16 | #include <Library/IoLib.h>\r | |
17 | #include <Library/SerialPortLib.h>\r | |
18 | \r | |
19 | //---------------------------------------------\r | |
20 | // UART Register Offsets\r | |
21 | //---------------------------------------------\r | |
22 | #define BAUD_LOW_OFFSET 0x00\r | |
23 | #define BAUD_HIGH_OFFSET 0x01\r | |
24 | #define IER_OFFSET 0x01\r | |
25 | #define LCR_SHADOW_OFFSET 0x01\r | |
26 | #define FCR_SHADOW_OFFSET 0x02\r | |
27 | #define IR_CONTROL_OFFSET 0x02\r | |
28 | #define FCR_OFFSET 0x02\r | |
29 | #define EIR_OFFSET 0x02\r | |
30 | #define BSR_OFFSET 0x03\r | |
31 | #define LCR_OFFSET 0x03\r | |
32 | #define MCR_OFFSET 0x04\r | |
33 | #define LSR_OFFSET 0x05\r | |
34 | #define MSR_OFFSET 0x06\r | |
35 | \r | |
36 | //---------------------------------------------\r | |
37 | // UART Register Bit Defines\r | |
38 | //---------------------------------------------\r | |
39 | #define LSR_TXRDY 0x20\r | |
40 | #define LSR_RXDA 0x01\r | |
41 | #define DLAB 0x01\r | |
42 | \r | |
43 | //---------------------------------------------\r | |
44 | // UART Settings\r | |
45 | //---------------------------------------------\r | |
46 | UINT16 gUartBase = 0x3F8;\r | |
47 | UINTN gBps = 115200;\r | |
48 | UINT8 gData = 8;\r | |
49 | UINT8 gStop = 1;\r | |
50 | UINT8 gParity = 0;\r | |
51 | UINT8 gBreakSet = 0;\r | |
52 | \r | |
53 | /**\r | |
54 | Initialize the serial device hardware.\r | |
55 | \r | |
56 | If no initialization is required, then return RETURN_SUCCESS.\r | |
57 | If the serial device was successfuly initialized, then return RETURN_SUCCESS.\r | |
58 | If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.\r | |
59 | \r | |
60 | @retval RETURN_SUCCESS The serial device was initialized.\r | |
61 | @retval RETURN_DEVICE_ERROR The serail device could not be initialized.\r | |
62 | \r | |
63 | **/\r | |
64 | RETURN_STATUS\r | |
65 | EFIAPI\r | |
66 | SerialPortInitialize (\r | |
67 | VOID\r | |
68 | )\r | |
69 | {\r | |
70 | UINTN Divisor;\r | |
71 | UINT8 OutputData;\r | |
72 | UINT8 Data;\r | |
73 | \r | |
74 | //\r | |
75 | // Map 5..8 to 0..3\r | |
76 | //\r | |
77 | Data = (UINT8) (gData - (UINT8) 5);\r | |
78 | \r | |
79 | //\r | |
80 | // Calculate divisor for baud generator\r | |
81 | //\r | |
82 | Divisor = 115200 / gBps;\r | |
83 | \r | |
84 | //\r | |
85 | // Set communications format\r | |
86 | //\r | |
87 | OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);\r | |
88 | IoWrite8 ((UINTN) (gUartBase + LCR_OFFSET), OutputData);\r | |
89 | \r | |
90 | //\r | |
91 | // Configure baud rate\r | |
92 | //\r | |
93 | IoWrite8 ((UINTN) (gUartBase + BAUD_HIGH_OFFSET), (UINT8) (Divisor >> 8));\r | |
94 | IoWrite8 ((UINTN) (gUartBase + BAUD_LOW_OFFSET), (UINT8) (Divisor & 0xff));\r | |
95 | \r | |
96 | //\r | |
97 | // Switch back to bank 0\r | |
98 | //\r | |
99 | OutputData = (UINT8) ((~DLAB << 7) | (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);\r | |
100 | IoWrite8 ((UINTN) (gUartBase + LCR_OFFSET), OutputData);\r | |
101 | \r | |
102 | return RETURN_SUCCESS;\r | |
103 | }\r | |
104 | \r | |
105 | /**\r | |
106 | Write data from buffer to serial device. \r | |
107 | \r | |
108 | Writes NumberOfBytes data bytes from Buffer to the serial device. \r | |
109 | The number of bytes actually written to the serial device is returned.\r | |
110 | If the return value is less than NumberOfBytes, then the write operation failed.\r | |
111 | \r | |
112 | If Buffer is NULL, then ASSERT(). \r | |
113 | \r | |
114 | If NumberOfBytes is zero, then return 0.\r | |
115 | \r | |
116 | @param Buffer Pointer to the data buffer to be written.\r | |
117 | @param NumberOfBytes Number of bytes to written to the serial device.\r | |
118 | \r | |
119 | @retval 0 NumberOfBytes is 0.\r | |
120 | @retval >0 The number of bytes written to the serial device. \r | |
121 | If this value is less than NumberOfBytes, then the read operation failed.\r | |
122 | \r | |
123 | **/\r | |
124 | UINTN\r | |
125 | EFIAPI\r | |
126 | SerialPortWrite (\r | |
127 | IN UINT8 *Buffer,\r | |
128 | IN UINTN NumberOfBytes\r | |
129 | )\r | |
130 | {\r | |
131 | UINTN Result;\r | |
132 | UINT8 Data;\r | |
133 | \r | |
134 | if (Buffer == NULL) {\r | |
135 | return 0;\r | |
136 | }\r | |
137 | \r | |
138 | Result = NumberOfBytes;\r | |
139 | \r | |
140 | while (NumberOfBytes--) {\r | |
141 | //\r | |
142 | // Wait for the serail port to be ready.\r | |
143 | //\r | |
144 | do {\r | |
145 | Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);\r | |
146 | } while ((Data & LSR_TXRDY) == 0);\r | |
147 | IoWrite8 ((UINT16) gUartBase, *Buffer++);\r | |
148 | }\r | |
149 | \r | |
150 | return Result;\r | |
151 | }\r | |
152 | \r | |
153 | \r | |
154 | /**\r | |
155 | Reads data from a serial device into a buffer.\r | |
156 | \r | |
157 | @param Buffer Pointer to the data buffer to store the data read from the serial device.\r | |
158 | @param NumberOfBytes Number of bytes to read from the serial device.\r | |
159 | \r | |
160 | @retval 0 NumberOfBytes is 0.\r | |
161 | @retval >0 The number of bytes read from the serial device. \r | |
162 | If this value is less than NumberOfBytes, then the read operation failed.\r | |
163 | \r | |
164 | **/\r | |
165 | UINTN\r | |
166 | EFIAPI\r | |
167 | SerialPortRead (\r | |
168 | OUT UINT8 *Buffer,\r | |
169 | IN UINTN NumberOfBytes\r | |
170 | )\r | |
171 | {\r | |
172 | UINTN Result;\r | |
173 | UINT8 Data;\r | |
174 | \r | |
175 | if (NULL == Buffer) {\r | |
176 | return 0;\r | |
177 | }\r | |
178 | \r | |
179 | Result = NumberOfBytes;\r | |
180 | \r | |
181 | while (NumberOfBytes--) {\r | |
182 | //\r | |
183 | // Wait for the serail port to be ready.\r | |
184 | //\r | |
185 | do {\r | |
186 | Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);\r | |
187 | } while ((Data & LSR_RXDA) == 0);\r | |
188 | \r | |
189 | *Buffer++ = IoRead8 ((UINT16) gUartBase);\r | |
190 | }\r | |
191 | \r | |
192 | return Result;\r | |
193 | }\r | |
194 | \r | |
195 | /**\r | |
196 | Polls a serial device to see if there is any data waiting to be read.\r | |
197 | \r | |
198 | Polls aserial device to see if there is any data waiting to be read.\r | |
199 | If there is data waiting to be read from the serial device, then TRUE is returned.\r | |
200 | If there is no data waiting to be read from the serial device, then FALSE is returned.\r | |
201 | \r | |
202 | @retval TRUE Data is waiting to be read from the serial device.\r | |
203 | @retval FALSE There is no data waiting to be read from the serial device.\r | |
204 | \r | |
205 | **/\r | |
206 | BOOLEAN\r | |
207 | EFIAPI\r | |
208 | SerialPortPoll (\r | |
209 | VOID\r | |
210 | )\r | |
211 | {\r | |
212 | UINT8 Data;\r | |
213 | \r | |
214 | //\r | |
215 | // Read the serial port status.\r | |
216 | //\r | |
217 | Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);\r | |
218 | \r | |
219 | return (BOOLEAN) ((Data & LSR_RXDA) != 0);\r | |
220 | }\r | |
221 | \r |