1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/ata.c	Tue Dec 06 12:56:46 2011 +0200
     1.3 @@ -0,0 +1,248 @@
     1.4 +#include <stdio.h>
     1.5 +#include <stdlib.h>
     1.6 +#include <string.h>
     1.7 +#include <inttypes.h>
     1.8 +#include <assert.h>
     1.9 +#include "ata.h"
    1.10 +#include "intr.h"
    1.11 +#include "asmops.h"
    1.12 +
    1.13 +/* registers */
    1.14 +#define REG_DATA		0	/* R/W */
    1.15 +#define REG_ERROR		1	/*  R  */
    1.16 +#define REG_FEATURES	1	/*  W  */
    1.17 +#define REG_COUNT		2	/* R/W */
    1.18 +#define REG_LBA0		3	/* R/W */
    1.19 +#define REG_LBA1		4	/* R/W */
    1.20 +#define REG_LBA2		5	/* R/W */
    1.21 +#define REG_DEVICE		6	/* R/W */
    1.22 +#define REG_CMD			7	/*  W  */
    1.23 +#define REG_STATUS		7	/*  R  */
    1.24 +
    1.25 +#define REG_CTL			518
    1.26 +#define REG_ALTSTAT		518
    1.27 +
    1.28 +/* status bit fields */
    1.29 +#define ST_ERR		(1 << 0)
    1.30 +#define ST_DRQ		(1 << 3)
    1.31 +#define ST_DRDY		(1 << 6)
    1.32 +#define ST_BSY		(1 << 7)
    1.33 +
    1.34 +/* device select bit in control register */
    1.35 +#define DEV_SEL(x)		(((x) & 1) << 4)
    1.36 +
    1.37 +/* ATA commands */
    1.38 +#define CMD_IDENTIFY	0xec
    1.39 +
    1.40 +
    1.41 +struct device {
    1.42 +	int id;		/* id of the device on its ATA interface (0 master, 1 slave) */
    1.43 +	int iface;	/* ATA interface for this device (0 or 1) */
    1.44 +	int port_base;	/* interface I/O port base */
    1.45 +
    1.46 +	uint32_t nsect_lba;
    1.47 +	uint64_t nsect_lba48;
    1.48 +};
    1.49 +
    1.50 +
    1.51 +static int identify(struct device *dev, int iface, int id);
    1.52 +static void select_dev(struct device *dev);
    1.53 +static int wait_busy(struct device *dev);
    1.54 +static int wait_drq(struct device *dev);
    1.55 +static void read_data(struct device *dev, void *buf);
    1.56 +static inline uint8_t read_reg8(struct device *dev, int reg);
    1.57 +static inline uint16_t read_reg16(struct device *dev, int reg);
    1.58 +static inline void write_reg8(struct device *dev, int reg, uint8_t val);
    1.59 +static inline void write_reg16(struct device *dev, int reg, uint16_t val);
    1.60 +static void ata_intr(int inum);
    1.61 +static char *size_str(uint64_t nsect, char *buf);
    1.62 +
    1.63 +/* last drive selected on each bus */
    1.64 +static int drvsel[2] = {-1, -1};
    1.65 +
    1.66 +/* 4 possible devices: 2 ATA interfaces with 2 devices each.
    1.67 + * this will never change unless we start querying the PCI config space
    1.68 + * for additional drives (in which case this whole init code must be
    1.69 + * rewritten anyway), but I like it spelt out like this.
    1.70 + */
    1.71 +#define MAX_IFACES		2
    1.72 +#define MAX_DEV			(MAX_IFACES * 2)
    1.73 +static struct device dev[MAX_DEV];
    1.74 +
    1.75 +
    1.76 +void init_ata(void)
    1.77 +{
    1.78 +	int i;
    1.79 +
    1.80 +	interrupt(IRQ_TO_INTR(15), ata_intr);
    1.81 +
    1.82 +	for(i=0; i<MAX_DEV; i++) {
    1.83 +		int iface = i / MAX_IFACES;
    1.84 +		int id = i % MAX_IFACES;
    1.85 +
    1.86 +		if(identify(dev + i, iface, id) == -1) {
    1.87 +			dev[i].id = -1;
    1.88 +		}
    1.89 +	}
    1.90 +}
    1.91 +
    1.92 +static int identify(struct device *dev, int iface, int id)
    1.93 +{
    1.94 +	/* base address of the two ATA interfaces */
    1.95 +	static const int port_base[] = {0x1f0, 0x170};
    1.96 +	unsigned char st;
    1.97 +	uint16_t *info;
    1.98 +	char textbuf[42];	/* at most we need 40 chars for ident strings */
    1.99 +
   1.100 +	dev->id = id;
   1.101 +	dev->iface = iface;
   1.102 +	dev->port_base = port_base[iface];
   1.103 +
   1.104 +	/* a status of 0xff means there's no drive on the interface */
   1.105 +	if((st = read_reg8(dev, REG_ALTSTAT)) == 0xff) {
   1.106 +		return -1;
   1.107 +	}
   1.108 +
   1.109 +	select_dev(dev);
   1.110 +	/* wait a bit to allow the device time to respond */
   1.111 +	iodelay(); iodelay(); iodelay(); iodelay();
   1.112 +
   1.113 +	write_reg8(dev, REG_CMD, CMD_IDENTIFY);
   1.114 +
   1.115 +	if(!(st = read_reg8(dev, REG_ALTSTAT)) || (st & ST_ERR)) {
   1.116 +		/* does not exist */
   1.117 +		return -1;
   1.118 +	}
   1.119 +	if(wait_busy(dev) == -1) {
   1.120 +		/* got ST_ERR, not ATA */
   1.121 +		return -1;
   1.122 +	}
   1.123 +
   1.124 +	info = malloc(512);
   1.125 +	assert(info);
   1.126 +
   1.127 +	/* read the device information */
   1.128 +	read_data(dev, info);
   1.129 +
   1.130 +	/* print model and serial */
   1.131 +	memcpy(textbuf, info + 27, 40);
   1.132 +	textbuf[40] = 0;
   1.133 +	printf("- found ata drive (%d,%d): %s\n", dev->iface, dev->id, textbuf);
   1.134 +
   1.135 +	memcpy(textbuf, info + 10, 20);
   1.136 +	textbuf[20] = 0;
   1.137 +	printf("  s/n: %s\n", textbuf);
   1.138 +
   1.139 +	dev->nsect_lba = *(uint32_t*)(info + 60);
   1.140 +	dev->nsect_lba48 = *(uint64_t*)(info + 100) & 0xffffffffffffull;
   1.141 +
   1.142 +	if(!dev->nsect_lba) {
   1.143 +		printf("  drive does not support LBA, ignoring!\n");
   1.144 +		free(info);
   1.145 +		return -1;
   1.146 +	}
   1.147 +
   1.148 +	if(dev->nsect_lba48) {
   1.149 +		size_str(dev->nsect_lba48, textbuf);
   1.150 +	} else {
   1.151 +		size_str(dev->nsect_lba, textbuf);
   1.152 +	}
   1.153 +	printf("  size: %s\n", textbuf);
   1.154 +
   1.155 +	free(info);
   1.156 +	return 0;
   1.157 +}
   1.158 +
   1.159 +static void select_dev(struct device *dev)
   1.160 +{
   1.161 +	/* if this is the currently selected device, thy work is done */
   1.162 +	if(drvsel[dev->iface] == dev->id)
   1.163 +		return;
   1.164 +
   1.165 +	/* wait for BSY and DRQ to clear */
   1.166 +	while(read_reg8(dev, REG_ALTSTAT) & (ST_BSY | ST_DRQ));
   1.167 +
   1.168 +	/* set the correct device bit to the device register */
   1.169 +	write_reg8(dev, REG_DEVICE, DEV_SEL(dev->id));
   1.170 +}
   1.171 +
   1.172 +static int wait_busy(struct device *dev)
   1.173 +{
   1.174 +	unsigned char st;
   1.175 +
   1.176 +	do {
   1.177 +		st = read_reg8(dev, REG_ALTSTAT);
   1.178 +	} while((st & ST_BSY) && !(st & ST_ERR));
   1.179 +
   1.180 +	return st & ST_ERR ? -1 : 0;
   1.181 +}
   1.182 +
   1.183 +static int wait_drq(struct device *dev)
   1.184 +{
   1.185 +	unsigned char st;
   1.186 +
   1.187 +	do {
   1.188 +		st = read_reg8(dev, REG_ALTSTAT);
   1.189 +	} while(!(st & (ST_DRQ | ST_ERR)));
   1.190 +
   1.191 +	return st & ST_ERR ? -1 : 0;
   1.192 +}
   1.193 +
   1.194 +static void read_data(struct device *dev, void *buf)
   1.195 +{
   1.196 +	int i;
   1.197 +	uint16_t *ptr = buf;
   1.198 +
   1.199 +	/* wait for the data request from the drive */
   1.200 +	wait_drq(dev);
   1.201 +
   1.202 +	/* ready to transfer */
   1.203 +	for(i=0; i<256; i++) {
   1.204 +		*ptr++ = read_reg16(dev, REG_DATA);
   1.205 +	}
   1.206 +}
   1.207 +
   1.208 +static inline uint8_t read_reg8(struct device *dev, int reg)
   1.209 +{
   1.210 +	uint8_t val;
   1.211 +	inb(val, dev->port_base + reg);
   1.212 +	return val;
   1.213 +}
   1.214 +
   1.215 +static inline uint16_t read_reg16(struct device *dev, int reg)
   1.216 +{
   1.217 +	uint16_t val;
   1.218 +	inw(val, dev->port_base + reg);
   1.219 +	return val;
   1.220 +}
   1.221 +
   1.222 +static inline void write_reg8(struct device *dev, int reg, uint8_t val)
   1.223 +{
   1.224 +	outb(val, dev->port_base + reg);
   1.225 +}
   1.226 +
   1.227 +static inline void write_reg16(struct device *dev, int reg, uint16_t val)
   1.228 +{
   1.229 +	outw(val, dev->port_base + reg);
   1.230 +}
   1.231 +
   1.232 +static void ata_intr(int inum)
   1.233 +{
   1.234 +	printf("ATA interrupt\n");
   1.235 +}
   1.236 +
   1.237 +static char *size_str(uint64_t nsect, char *buf)
   1.238 +{
   1.239 +	static const char *suffix[] = {"kb", "mb", "gb", "tb", "pb", 0};
   1.240 +	int i;
   1.241 +
   1.242 +	/* start with kilobytes */
   1.243 +	nsect /= 2;
   1.244 +
   1.245 +	for(i=0; nsect >= 1024 && suffix[i + 1]; i++) {
   1.246 +		nsect /= 1024;
   1.247 +	}
   1.248 +	sprintf(buf, "%u %s", (unsigned int)nsect, suffix[i]);
   1.249 +	return buf;
   1.250 +}
   1.251 +