1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** LevelX Component */
17 /** */
18 /** NOR Flash */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 #define LX_SOURCE_CODE
24
25
26 /* Disable ThreadX error checking. */
27
28 #ifndef LX_DISABLE_ERROR_CHECKING
29 #define LX_DISABLE_ERROR_CHECKING
30 #endif
31
32
33 /* Include necessary system files. */
34
35 #include "lx_api.h"
36
37
38 /**************************************************************************/
39 /* */
40 /* FUNCTION RELEASE */
41 /* */
42 /* _lx_nor_flash_extended_cache_read PORTABLE C */
43 /* 6.2.1 */
44 /* AUTHOR */
45 /* */
46 /* William E. Lamie, Microsoft Corporation */
47 /* */
48 /* DESCRIPTION */
49 /* */
50 /* This function performs a read of the NOR flash memory. */
51 /* */
52 /* INPUT */
53 /* */
54 /* nor_flash NOR flash instance */
55 /* flash_address Address of NOR flash to read */
56 /* destination Destination for the read */
57 /* words Number of words to read */
58 /* */
59 /* OUTPUT */
60 /* */
61 /* return status */
62 /* */
63 /* CALLS */
64 /* */
65 /* (lx_nor_flash_driver_read) Actual driver read */
66 /* */
67 /* CALLED BY */
68 /* */
69 /* Application Code */
70 /* */
71 /* RELEASE HISTORY */
72 /* */
73 /* DATE NAME DESCRIPTION */
74 /* */
75 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
76 /* 09-30-2020 William E. Lamie Modified comment(s), */
77 /* resulting in version 6.1 */
78 /* 06-02-2021 Bhupendra Naphade Modified comment(s), */
79 /* resulting in version 6.1.7 */
80 /* 03-08-2023 Xiuwen Cai Modified comment(s), */
81 /* added new driver interface, */
82 /* resulting in version 6.2.1 */
83 /* */
84 /**************************************************************************/
_lx_nor_flash_driver_read(LX_NOR_FLASH * nor_flash,ULONG * flash_address,ULONG * destination,ULONG words)85 UINT _lx_nor_flash_driver_read(LX_NOR_FLASH *nor_flash, ULONG *flash_address, ULONG *destination, ULONG words)
86 {
87 #ifndef LX_NOR_DISABLE_EXTENDED_CACHE
88
89 UINT status;
90 UINT i;
91 ULONG *cache_entry_start;
92 ULONG *cache_entry_end;
93 ULONG cache_offset;
94 UINT least_used_cache_entry;
95
96
97 /* Is the request a whole sector or a partial sector. */
98 if ((words == 1) && (nor_flash -> lx_nor_flash_extended_cache_entries))
99 {
100
101 /* One word request, which implies that it is a NOR flash metadata read. */
102
103
104 /* Initialize the least used cache entry. */
105 least_used_cache_entry = 0;
106
107 do
108 {
109
110 /* Loop through the cache entries to see if there is a sector in cache. */
111 for (i = 0; i < nor_flash -> lx_nor_flash_extended_cache_entries; i++)
112 {
113
114 /* Search through the cache to find the entry. */
115
116 /* Determine the cache entry addresses. */
117 cache_entry_start = nor_flash -> lx_nor_flash_extended_cache[i].lx_nor_flash_extended_cache_entry_sector_address;
118 cache_entry_end = cache_entry_start + LX_NOR_SECTOR_SIZE;
119
120 /* Determine if the flash address in in the cache entry. */
121 if ((cache_entry_start) && (flash_address >= cache_entry_start) && (flash_address < cache_entry_end))
122 {
123
124 /* Yes, we found the entry. */
125
126 /* Increment the accessed count. */
127 nor_flash -> lx_nor_flash_extended_cache[i].lx_nor_flash_extended_cache_entry_access_count++;
128
129 /* Calculate the offset into the cache entry. */
130 cache_offset = (ULONG)(flash_address - cache_entry_start);
131
132 /* Copy the word from the cache. */
133 *destination = *(nor_flash -> lx_nor_flash_extended_cache[i].lx_nor_flash_extended_cache_entry_sector_memory + cache_offset);
134
135 /* Increment the number of cache hits. */
136 nor_flash -> lx_nor_flash_extended_cache_hits++;
137
138 /* Return success. */
139 return(LX_SUCCESS);
140 }
141 else
142 {
143
144 /* Determine if we have a new least used sector. */
145 if (i != least_used_cache_entry)
146 {
147
148 /* Determine if this entry has a smaller accessed count. */
149 if (nor_flash -> lx_nor_flash_extended_cache[i].lx_nor_flash_extended_cache_entry_access_count <
150 nor_flash -> lx_nor_flash_extended_cache[least_used_cache_entry].lx_nor_flash_extended_cache_entry_access_count)
151 {
152
153 /* New least used entry. */
154 least_used_cache_entry = i;
155 }
156 }
157 }
158 }
159
160 /* Now read in the sector into the cache. */
161 cache_offset = (ULONG)(flash_address - nor_flash -> lx_nor_flash_base_address);
162 cache_offset = cache_offset & ~((ULONG) (LX_NOR_SECTOR_SIZE-1));
163 cache_entry_start = nor_flash -> lx_nor_flash_base_address + cache_offset;
164
165 /* Call the actual driver read function. */
166 #ifdef LX_NOR_ENABLE_CONTROL_BLOCK_FOR_DRIVER_INTERFACE
167 status = (nor_flash -> lx_nor_flash_driver_read)(nor_flash, cache_entry_start,
168 nor_flash -> lx_nor_flash_extended_cache[least_used_cache_entry].lx_nor_flash_extended_cache_entry_sector_memory,
169 LX_NOR_SECTOR_SIZE);
170 #else
171 status = (nor_flash -> lx_nor_flash_driver_read)(cache_entry_start,
172 nor_flash -> lx_nor_flash_extended_cache[least_used_cache_entry].lx_nor_flash_extended_cache_entry_sector_memory,
173 LX_NOR_SECTOR_SIZE);
174 #endif
175
176 /* Determine if there was an error. */
177 if (status != LX_SUCCESS)
178 {
179
180 /* Return the error to the caller. */
181 return(status);
182 }
183
184 /* Setup the cache entry. */
185 nor_flash -> lx_nor_flash_extended_cache[least_used_cache_entry].lx_nor_flash_extended_cache_entry_sector_address = cache_entry_start;
186 nor_flash -> lx_nor_flash_extended_cache[least_used_cache_entry].lx_nor_flash_extended_cache_entry_access_count = 0;
187
188 /* Increment the number of cache misses. */
189 nor_flash -> lx_nor_flash_extended_cache_misses++;
190
191 /* Decrement the number of cache hits, so that the increment that will happen next will be cancelled out. */
192 nor_flash -> lx_nor_flash_extended_cache_hits--;
193
194 } while (status == LX_SUCCESS);
195
196 /* Return success. */
197 return(LX_SUCCESS);
198 }
199 else
200 {
201
202 /* Call the actual driver read function. */
203 #ifdef LX_NOR_ENABLE_CONTROL_BLOCK_FOR_DRIVER_INTERFACE
204 status = (nor_flash -> lx_nor_flash_driver_read)(nor_flash, flash_address, destination, words);
205 #else
206 status = (nor_flash -> lx_nor_flash_driver_read)(flash_address, destination, words);
207 #endif
208
209 /* Return completion status. */
210 return(status);
211 }
212 #else
213 UINT status;
214
215
216 /* Call the actual driver read function. */
217 #ifdef LX_NOR_ENABLE_CONTROL_BLOCK_FOR_DRIVER_INTERFACE
218 status = (nor_flash -> lx_nor_flash_driver_read)(nor_flash, flash_address, destination, words);
219 #else
220 status = (nor_flash -> lx_nor_flash_driver_read)(flash_address, destination, words);
221 #endif
222
223 /* Return completion status. */
224 return(status);
225 #endif
226 }
227
228
229
