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fixed the "endianess" of the text messages in the ATA identify info block. this is the first time I've seen wrong byteorder in ascii text, the ATA committee should be commended.
author John Tsiombikas <nuclear@member.fsf.org>
date Tue, 06 Dec 2011 13:35:39 +0200
parents 251a65b62223
children 9c979413cfbf
line source
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <inttypes.h>
5 #include <assert.h>
6 #include "ata.h"
7 #include "intr.h"
8 #include "asmops.h"
9
10 /* registers */
11 #define REG_DATA 0 /* R/W */
12 #define REG_ERROR 1 /* R */
13 #define REG_FEATURES 1 /* W */
14 #define REG_COUNT 2 /* R/W */
15 #define REG_LBA0 3 /* R/W */
16 #define REG_LBA1 4 /* R/W */
17 #define REG_LBA2 5 /* R/W */
18 #define REG_DEVICE 6 /* R/W */
19 #define REG_CMD 7 /* W */
20 #define REG_STATUS 7 /* R */
21
22 #define REG_CTL 518
23 #define REG_ALTSTAT 518
24
25 /* status bit fields */
26 #define ST_ERR (1 << 0)
27 #define ST_DRQ (1 << 3)
28 #define ST_DRDY (1 << 6)
29 #define ST_BSY (1 << 7)
30
31 /* device select bit in control register */
32 #define DEV_SEL(x) (((x) & 1) << 4)
33
34 /* ATA commands */
35 #define CMD_IDENTIFY 0xec
36
37
38 struct device {
39 int id; /* id of the device on its ATA interface (0 master, 1 slave) */
40 int iface; /* ATA interface for this device (0 or 1) */
41 int port_base; /* interface I/O port base */
42
43 uint32_t nsect_lba;
44 uint64_t nsect_lba48;
45 };
46
47
48 static int identify(struct device *dev, int iface, int id);
49 static void select_dev(struct device *dev);
50 static int wait_busy(struct device *dev);
51 static int wait_drq(struct device *dev);
52 static void read_data(struct device *dev, void *buf);
53 static inline uint8_t read_reg8(struct device *dev, int reg);
54 static inline uint16_t read_reg16(struct device *dev, int reg);
55 static inline void write_reg8(struct device *dev, int reg, uint8_t val);
56 static inline void write_reg16(struct device *dev, int reg, uint16_t val);
57 static void ata_intr(int inum);
58 static void *atastr(void *res, void *src, int n);
59 static char *size_str(uint64_t nsect, char *buf);
60
61 /* last drive selected on each bus */
62 static int drvsel[2] = {-1, -1};
63
64 /* 4 possible devices: 2 ATA interfaces with 2 devices each.
65 * this will never change unless we start querying the PCI config space
66 * for additional drives (in which case this whole init code must be
67 * rewritten anyway), but I like it spelt out like this.
68 */
69 #define MAX_IFACES 2
70 #define MAX_DEV (MAX_IFACES * 2)
71 static struct device dev[MAX_DEV];
72
73
74 void init_ata(void)
75 {
76 int i;
77
78 interrupt(IRQ_TO_INTR(15), ata_intr);
79
80 for(i=0; i<MAX_DEV; i++) {
81 int iface = i / MAX_IFACES;
82 int id = i % MAX_IFACES;
83
84 if(identify(dev + i, iface, id) == -1) {
85 dev[i].id = -1;
86 }
87 }
88 }
89
90 static int identify(struct device *dev, int iface, int id)
91 {
92 /* base address of the two ATA interfaces */
93 static const int port_base[] = {0x1f0, 0x170};
94 unsigned char st;
95 uint16_t *info;
96 char textbuf[42]; /* at most we need 40 chars for ident strings */
97
98 dev->id = id;
99 dev->iface = iface;
100 dev->port_base = port_base[iface];
101
102 /* a status of 0xff means there's no drive on the interface */
103 if((st = read_reg8(dev, REG_ALTSTAT)) == 0xff) {
104 return -1;
105 }
106
107 select_dev(dev);
108 /* wait a bit to allow the device time to respond */
109 iodelay(); iodelay(); iodelay(); iodelay();
110
111 write_reg8(dev, REG_CMD, CMD_IDENTIFY);
112
113 if(!(st = read_reg8(dev, REG_ALTSTAT)) || (st & ST_ERR)) {
114 /* does not exist */
115 return -1;
116 }
117 if(wait_busy(dev) == -1) {
118 /* got ST_ERR, not ATA */
119 return -1;
120 }
121
122 info = malloc(512);
123 assert(info);
124
125 /* read the device information */
126 read_data(dev, info);
127
128 /* print model and serial */
129 printf("- found ata drive (%d,%d): %s\n", dev->iface, dev->id, atastr(textbuf, info + 27, 40));
130 printf(" s/n: %s\n", atastr(textbuf, info + 10, 20));
131
132 dev->nsect_lba = *(uint32_t*)(info + 60);
133 dev->nsect_lba48 = *(uint64_t*)(info + 100) & 0xffffffffffffull;
134
135 if(!dev->nsect_lba) {
136 printf(" drive does not support LBA, ignoring!\n");
137 free(info);
138 return -1;
139 }
140
141 if(dev->nsect_lba48) {
142 size_str(dev->nsect_lba48, textbuf);
143 } else {
144 size_str(dev->nsect_lba, textbuf);
145 }
146 printf(" size: %s\n", textbuf);
147
148 free(info);
149 return 0;
150 }
151
152 static void select_dev(struct device *dev)
153 {
154 /* if this is the currently selected device, thy work is done */
155 if(drvsel[dev->iface] == dev->id)
156 return;
157
158 /* wait for BSY and DRQ to clear */
159 while(read_reg8(dev, REG_ALTSTAT) & (ST_BSY | ST_DRQ));
160
161 /* set the correct device bit to the device register */
162 write_reg8(dev, REG_DEVICE, DEV_SEL(dev->id));
163 }
164
165 static int wait_busy(struct device *dev)
166 {
167 unsigned char st;
168
169 do {
170 st = read_reg8(dev, REG_ALTSTAT);
171 } while((st & ST_BSY) && !(st & ST_ERR));
172
173 return st & ST_ERR ? -1 : 0;
174 }
175
176 static int wait_drq(struct device *dev)
177 {
178 unsigned char st;
179
180 do {
181 st = read_reg8(dev, REG_ALTSTAT);
182 } while(!(st & (ST_DRQ | ST_ERR)));
183
184 return st & ST_ERR ? -1 : 0;
185 }
186
187 static void read_data(struct device *dev, void *buf)
188 {
189 int i;
190 uint16_t *ptr = buf;
191
192 /* wait for the data request from the drive */
193 wait_drq(dev);
194
195 /* ready to transfer */
196 for(i=0; i<256; i++) {
197 *ptr++ = read_reg16(dev, REG_DATA);
198 }
199 }
200
201 static inline uint8_t read_reg8(struct device *dev, int reg)
202 {
203 uint8_t val;
204 inb(val, dev->port_base + reg);
205 return val;
206 }
207
208 static inline uint16_t read_reg16(struct device *dev, int reg)
209 {
210 uint16_t val;
211 inw(val, dev->port_base + reg);
212 return val;
213 }
214
215 static inline void write_reg8(struct device *dev, int reg, uint8_t val)
216 {
217 outb(val, dev->port_base + reg);
218 }
219
220 static inline void write_reg16(struct device *dev, int reg, uint16_t val)
221 {
222 outw(val, dev->port_base + reg);
223 }
224
225 static void ata_intr(int inum)
226 {
227 printf("ATA interrupt\n");
228 }
229
230 static void *atastr(void *res, void *src, int n)
231 {
232 int i;
233 uint16_t *sptr = (uint16_t*)src;
234 char *dptr = res;
235
236 for(i=0; i<n/2; i++) {
237 *dptr++ = (*sptr & 0xff00) >> 8;
238 *dptr++ = *sptr++ & 0xff;
239 }
240 *dptr = 0;
241 return res;
242 }
243
244 static char *size_str(uint64_t nsect, char *buf)
245 {
246 static const char *suffix[] = {"kb", "mb", "gb", "tb", "pb", 0};
247 int i;
248
249 /* start with kilobytes */
250 nsect /= 2;
251
252 for(i=0; nsect >= 1024 && suffix[i + 1]; i++) {
253 nsect /= 1024;
254 }
255 sprintf(buf, "%u %s", (unsigned int)nsect, suffix[i]);
256 return buf;
257 }
258