1 /*
2  * atmel_df_pow2.c - convert Atmel Dataflashes to Power of 2 mode
3  *
4  * Copyright 2009 Analog Devices Inc.
5  *
6  * Licensed under the 2-clause BSD.
7  */
8 
9 #include <common.h>
10 #include <exports.h>
11 #include <spi.h>
12 
13 #define CMD_ID    0x9f
14 #define CMD_STAT  0xd7
15 #define CMD_CFG   0x3d
16 
17 static int flash_cmd(struct spi_slave *slave, uchar cmd, uchar *buf, int len)
18 {
19 	buf[0] = cmd;
20 	return spi_xfer(slave, 8 * len, buf, buf, SPI_XFER_BEGIN | SPI_XFER_END);
21 }
22 
23 static int flash_status(struct spi_slave *slave)
24 {
25 	uchar buf[2];
26 	if (flash_cmd(slave, CMD_STAT, buf, sizeof(buf)))
27 		return -1;
28 	return buf[1];
29 }
30 
31 static int flash_set_pow2(struct spi_slave *slave)
32 {
33 	int ret;
34 	uchar buf[4];
35 
36 	buf[1] = 0x2a;
37 	buf[2] = 0x80;
38 	buf[3] = 0xa6;
39 
40 	ret = flash_cmd(slave, CMD_CFG, buf, sizeof(buf));
41 	if (ret)
42 		return ret;
43 
44 	/* wait Tp, or 6 msec */
45 	udelay(6000);
46 
47 	ret = flash_status(slave);
48 	if (ret == -1)
49 		return 1;
50 
51 	return ret & 0x1 ? 0 : 1;
52 }
53 
54 static int flash_check(struct spi_slave *slave)
55 {
56 	int ret;
57 	uchar buf[4];
58 
59 	ret = flash_cmd(slave, CMD_ID, buf, sizeof(buf));
60 	if (ret)
61 		return ret;
62 
63 	if (buf[1] != 0x1F) {
64 		printf("atmel flash not found (id[0] = %#x)\n", buf[1]);
65 		return 1;
66 	}
67 
68 	if ((buf[2] >> 5) != 0x1) {
69 		printf("AT45 flash not found (id[0] = %#x)\n", buf[2]);
70 		return 2;
71 	}
72 
73 	return 0;
74 }
75 
76 static char *getline(void)
77 {
78 	static char buffer[100];
79 	char c;
80 	size_t i;
81 
82 	i = 0;
83 	while (1) {
84 		buffer[i] = '\0';
85 
86 		c = getc();
87 
88 		switch (c) {
89 		case '\r':	/* Enter/Return key */
90 		case '\n':
91 			puts("\n");
92 			return buffer;
93 
94 		case 0x03:	/* ^C - break */
95 			return NULL;
96 
97 		case 0x5F:
98 		case 0x08:	/* ^H  - backspace */
99 		case 0x7F:	/* DEL - backspace */
100 			if (i) {
101 				puts("\b \b");
102 				i--;
103 			}
104 			break;
105 
106 		default:
107 			/* Ignore control characters */
108 			if (c < 0x20)
109 				break;
110 			/* Queue up all other characters */
111 			buffer[i++] = c;
112 			printf("%c", c);
113 			break;
114 		}
115 	}
116 }
117 
118 int atmel_df_pow2(int argc, char * const argv[])
119 {
120 	/* Print the ABI version */
121 	app_startup(argv);
122 	if (XF_VERSION != get_version()) {
123 		printf("Expects ABI version %d\n", XF_VERSION);
124 		printf("Actual U-Boot ABI version %lu\n", get_version());
125 		printf("Can't run\n\n");
126 		return 1;
127 	}
128 
129 	while (1) {
130 		struct spi_slave *slave;
131 		char *line, *p;
132 		int bus, cs, status;
133 
134 		puts("\nenter the [BUS:]CS of the SPI flash: ");
135 		line = getline();
136 
137 		/* CTRL+C */
138 		if (!line)
139 			return 0;
140 		if (line[0] == '\0')
141 			continue;
142 
143 		bus = cs = simple_strtoul(line, &p, 10);
144 		if (*p) {
145 			if (*p == ':') {
146 				++p;
147 				cs = simple_strtoul(p, &p, 10);
148 			}
149 			if (*p) {
150 				puts("invalid format, please try again\n");
151 				continue;
152 			}
153 		} else
154 			bus = 0;
155 
156 		printf("\ngoing to work with dataflash at %i:%i\n", bus, cs);
157 
158 		/* use a low speed -- it'll work with all devices, and
159 		 * speed here doesn't really matter.
160 		 */
161 		slave = spi_setup_slave(bus, cs, 1000, SPI_MODE_3);
162 		if (!slave) {
163 			puts("unable to setup slave\n");
164 			continue;
165 		}
166 
167 		if (spi_claim_bus(slave)) {
168 			spi_free_slave(slave);
169 			continue;
170 		}
171 
172 		if (flash_check(slave)) {
173 			puts("no flash found\n");
174 			goto done;
175 		}
176 
177 		status = flash_status(slave);
178 		if (status == -1) {
179 			puts("unable to read status register\n");
180 			goto done;
181 		}
182 		if (status & 0x1) {
183 			puts("flash is already in power-of-2 mode!\n");
184 			goto done;
185 		}
186 
187 		puts("are you sure you wish to set power-of-2 mode?\n");
188 		puts("this operation is permanent and irreversible\n");
189 		printf("enter YES to continue: ");
190 		line = getline();
191 		if (!line || strcmp(line, "YES"))
192 			goto done;
193 
194 		if (flash_set_pow2(slave)) {
195 			puts("setting pow2 mode failed\n");
196 			goto done;
197 		}
198 
199 		puts(
200 			"Configuration should be updated now.  You will have to\n"
201 			"power cycle the part in order to finish the conversion.\n"
202 		);
203 
204  done:
205 		spi_release_bus(slave);
206 		spi_free_slave(slave);
207 	}
208 }
209