1 | /***************************************************************** |
---|
2 | * File: sd_spi.c |
---|
3 | * Copyright (c) 2013 Mango Communications, all rights reseved |
---|
4 | * Released under the WARP License |
---|
5 | * See http://warpproject.org/license for details |
---|
6 | *****************************************************************/ |
---|
7 | #include "sd_spi.h" |
---|
8 | |
---|
9 | inline u8 simple_spi_read(u32 baseaddr) { |
---|
10 | Xil_Out32(baseaddr + SSPI_REG_SPITX, 0xFF); |
---|
11 | return (u8)(Xil_In32(baseaddr + SSPI_REG_SPIRX) & 0xFF); |
---|
12 | } |
---|
13 | |
---|
14 | inline void simple_spi_write(u32 baseaddr, u8 txByte) { |
---|
15 | Xil_Out32(baseaddr + SSPI_REG_SPITX, (u32)(txByte & 0xFF)); |
---|
16 | return; |
---|
17 | } |
---|
18 | |
---|
19 | void sd_send_cmd(u32 ba, u8 cmd, u32 args, u8 last_byte) { |
---|
20 | |
---|
21 | simple_spi_write(ba, 0xFF); //flush that Sandisk cards seem to require... |
---|
22 | simple_spi_write(ba, cmd); |
---|
23 | simple_spi_write(ba, (u8)(0xFF & (args>>24))); |
---|
24 | simple_spi_write(ba, (u8)(0xFF & (args>>16))); |
---|
25 | simple_spi_write(ba, (u8)(0xFF & (args>> 8))); |
---|
26 | simple_spi_write(ba, (u8)(0xFF & (args>> 0))); |
---|
27 | simple_spi_write(ba, last_byte); |
---|
28 | } |
---|
29 | |
---|
30 | |
---|
31 | int sd_read_block(u32 ba, u32 blk_offset, u8* buf, u32 blk_size) { |
---|
32 | int i; |
---|
33 | u8 rx_byte; |
---|
34 | |
---|
35 | sd_send_cmd(ba, SD_CMD17, blk_offset, 0x01); |
---|
36 | |
---|
37 | for(i=0; i<8; i++) { |
---|
38 | rx_byte = simple_spi_read(ba); |
---|
39 | if(rx_byte == 0xFF) continue; |
---|
40 | if(rx_byte == 0x00) break; |
---|
41 | } |
---|
42 | |
---|
43 | for(i=0; i<100; i++) { |
---|
44 | usleep(10000); |
---|
45 | rx_byte = simple_spi_read(ba); |
---|
46 | if(rx_byte == SD_DATA_TOKEN_RD) break; |
---|
47 | } |
---|
48 | if(i==100) {xil_printf("sd_read_block: No token received - Quitting\n"); return -1;} |
---|
49 | |
---|
50 | //Read exactly blk_size bytes |
---|
51 | for(i=0; i<blk_size; i++) { |
---|
52 | buf[i] = simple_spi_read(ba); |
---|
53 | } |
---|
54 | |
---|
55 | //Read and discard CRC bytes |
---|
56 | simple_spi_read(ba); |
---|
57 | simple_spi_read(ba); |
---|
58 | |
---|
59 | return 0; |
---|
60 | } |
---|
61 | |
---|
62 | int sd_write_block(u32 ba, u32 blk_offset, u8* buf, u32 blk_size) { |
---|
63 | int i; |
---|
64 | u8 rx_byte; |
---|
65 | |
---|
66 | sd_send_cmd(ba, SD_CMD24, blk_offset, 0x01); |
---|
67 | |
---|
68 | for(i=0; i<8; i++) { |
---|
69 | rx_byte = simple_spi_read(ba); |
---|
70 | if(rx_byte == 0xFF) continue; |
---|
71 | if(rx_byte == 0x00) break; |
---|
72 | } |
---|
73 | if(i==8) {xil_printf("CMD24 error - invalid response\n"); return -1;} |
---|
74 | |
---|
75 | //Send 1-byte write token |
---|
76 | simple_spi_write(ba, SD_DATA_TOKEN_WR_SINGLE); |
---|
77 | |
---|
78 | //Send blk_size bytes |
---|
79 | for(i=0; i<blk_size; i++) { |
---|
80 | simple_spi_write(ba, buf[i]); |
---|
81 | } |
---|
82 | |
---|
83 | //Write dummy 2-byte CRC (CRC not checked in SPI mode) |
---|
84 | simple_spi_write(ba, 0xFF); |
---|
85 | simple_spi_write(ba, 0xFF); |
---|
86 | |
---|
87 | //Read data response |
---|
88 | rx_byte = simple_spi_read(ba); |
---|
89 | if((rx_byte & 0x1F) != 0x05) {xil_printf("Write data response indicated error[%2d]: 0x%02x\n", i, rx_byte); return -1;} |
---|
90 | |
---|
91 | //Wait for SD card to indicate write is finished |
---|
92 | rx_byte = 0x00; i=0; |
---|
93 | while(rx_byte != 0xFF) { |
---|
94 | rx_byte = simple_spi_read(ba); |
---|
95 | i++; |
---|
96 | } |
---|
97 | //xil_printf("Idle after %d byte reads\n", i); |
---|
98 | |
---|
99 | return 0; |
---|
100 | } |
---|
101 | |
---|
102 | int sd_rw_init(u32 ba) { |
---|
103 | int i, j; |
---|
104 | int init_tries; |
---|
105 | u8 sd_idle; |
---|
106 | u8 rx_byte; |
---|
107 | |
---|
108 | //SD cards I tested don't seem to require a slow clock for init |
---|
109 | |
---|
110 | //CLK_DIV param selects bit index in clk counter |
---|
111 | // Higher index -> faster SCLK |
---|
112 | // For 80MHz bus clock CLK_DIV=6 -> SCLK=20MHz |
---|
113 | simple_spi_set_clkDiv(ba, 6); |
---|
114 | |
---|
115 | //CMD0 sometimes fails on the first try - try it twice before punting |
---|
116 | for(j=0; j<2; j++) { |
---|
117 | //SD init requires >74 SCLK cycles with CS de-asserted and MOSI = 1 |
---|
118 | simple_spi_set_cs(ba, 0); |
---|
119 | for(i=0; i<20; i++) { |
---|
120 | simple_spi_write(ba, 0xFF); |
---|
121 | } |
---|
122 | |
---|
123 | //Wait for a while before sending IDLE command |
---|
124 | usleep(10000); |
---|
125 | |
---|
126 | //Assert CS and leave asserted |
---|
127 | simple_spi_set_cs(ba, 1); |
---|
128 | |
---|
129 | //Send GO_IDLE command |
---|
130 | // 0x95 is valid CRC for CMD0 msg |
---|
131 | // Later cmds don't need CRC (ignored in SPI mode) |
---|
132 | sd_send_cmd(ba, SD_CMD0, 0x0, 0x95); |
---|
133 | |
---|
134 | //Wait for command response |
---|
135 | // Response should be 0x01 = No errors, IDLE=1 |
---|
136 | for(i=0; i<32; i++) { |
---|
137 | rx_byte = simple_spi_read(ba); |
---|
138 | |
---|
139 | if(rx_byte == 0xFF) continue; |
---|
140 | else if(rx_byte == 0x01) break; |
---|
141 | } |
---|
142 | if(j==1 && i==32) { |
---|
143 | //Punt if both CMD0 attempts fail |
---|
144 | xil_printf("Error in CMD0 - no valid response\n"); |
---|
145 | return -1; |
---|
146 | } |
---|
147 | } |
---|
148 | |
---|
149 | //Start SD card init with CMD55-ACMD41 sequence |
---|
150 | // Keep sending these commands until the card reports not-IDLE |
---|
151 | sd_idle = 1; |
---|
152 | init_tries = 0; |
---|
153 | while((sd_idle == 1) && (init_tries < 64)) { |
---|
154 | sd_send_cmd(ba, SD_CMD55, 0x0, 0x01); |
---|
155 | for(i=0; i<8; i++) { |
---|
156 | rx_byte = simple_spi_read(ba); |
---|
157 | if(rx_byte == 0xFF) continue; |
---|
158 | //xil_printf("CMD55 [%02d]: rx_byte = 0x%02x\n", i, rx_byte); |
---|
159 | if((rx_byte & 0x1) == 0) {sd_idle = 0; break;} |
---|
160 | } |
---|
161 | |
---|
162 | sd_send_cmd(ba, SD_ACMD41, 0x0, 0x01); |
---|
163 | for(i=0; i<8; i++) { |
---|
164 | rx_byte = simple_spi_read(ba); |
---|
165 | if(rx_byte == 0xFF) continue; |
---|
166 | //xil_printf("ACMD41 [%02d]: rx_byte = 0x%02x\n", i, rx_byte); |
---|
167 | if((rx_byte & 0x1) == 0) {sd_idle = 0; break;} |
---|
168 | } |
---|
169 | usleep(100000); |
---|
170 | init_tries++; |
---|
171 | } |
---|
172 | if(sd_idle == 1) {xil_printf("Error in SD init - ACMD41 never reported not IDLE\n"); return -1;} |
---|
173 | |
---|
174 | //Set block length to 512B |
---|
175 | sd_send_cmd(ba, SD_CMD16, SD_BLK_SIZE, 0x01); |
---|
176 | for(i=0; i<8; i++) { |
---|
177 | rx_byte = simple_spi_read(ba); |
---|
178 | if(rx_byte == 0xFF) continue; |
---|
179 | if(rx_byte == 0x00) break; |
---|
180 | } |
---|
181 | if(i==8) {xil_printf("Error in CMD16 - no valid response\n"); return -1;} |
---|
182 | |
---|
183 | return 0; |
---|
184 | } |
---|