Viewing file:  macio-adb.c (5.55 KB) -rw-r--r--
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/*
* Driver for the ADB controller in the Mac I/O (Hydra) chip.
*/
#include <stdarg.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <asm/prom.h>
#include <linux/adb.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/hydra.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <linux/init.h>
struct preg {
unsigned char r;
char pad[15];
};
struct adb_regs {
struct preg intr;
struct preg data[9];
struct preg intr_enb;
struct preg dcount;
struct preg error;
struct preg ctrl;
struct preg autopoll;
struct preg active_hi;
struct preg active_lo;
struct preg test;
};
/* Bits in intr and intr_enb registers */
#define DFB 1 /* data from bus */
#define TAG 2 /* transfer access grant */
/* Bits in dcount register */
#define HMB 0x0f /* how many bytes */
#define APD 0x10 /* auto-poll data */
/* Bits in error register */
#define NRE 1 /* no response error */
#define DLE 2 /* data lost error */
/* Bits in ctrl register */
#define TAR 1 /* transfer access request */
#define DTB 2 /* data to bus */
#define CRE 4 /* command response expected */
#define ADB_RST 8 /* ADB reset */
/* Bits in autopoll register */
#define APE 1 /* autopoll enable */
static volatile struct adb_regs *adb;
static struct adb_request *current_req, *last_req;
static unsigned char adb_rbuf[16];
static int macio_probe(void);
static int macio_init(void);
static void macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs);
static int macio_send_request(struct adb_request *req, int sync);
static int macio_adb_autopoll(int devs);
static void macio_adb_poll(void);
static int macio_adb_reset_bus(void);
static void completed(void);
struct adb_driver macio_adb_driver = {
"MACIO",
macio_probe,
macio_init,
macio_send_request,
/*macio_write,*/
macio_adb_autopoll,
macio_adb_poll,
macio_adb_reset_bus
};
int macio_probe(void)
{
return find_compatible_devices("adb", "chrp,adb0")? 0: -ENODEV;
}
int macio_init(void)
{
struct device_node *adbs;
adbs = find_compatible_devices("adb", "chrp,adb0");
if (adbs == 0)
return -ENXIO;
#if 0
{ int i;
printk("macio_adb_init: node = %p, addrs =", adbs->node);
for (i = 0; i < adbs->n_addrs; ++i)
printk(" %x(%x)", adbs->addrs[i].address, adbs->addrs[i].size);
printk(", intrs =");
for (i = 0; i < adbs->n_intrs; ++i)
printk(" %x", adbs->intrs[i].line);
printk("\n"); }
#endif
adb = (volatile struct adb_regs *)
ioremap(adbs->addrs->address, sizeof(struct adb_regs));
if (request_irq(adbs->intrs[0].line, macio_adb_interrupt,
0, "ADB", (void *)0)) {
printk(KERN_ERR "ADB: can't get irq %d\n",
adbs->intrs[0].line);
return -EAGAIN;
}
out_8(&adb->ctrl.r, 0);
out_8(&adb->intr.r, 0);
out_8(&adb->error.r, 0);
out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */
out_8(&adb->active_lo.r, 0xff);
out_8(&adb->autopoll.r, APE);
out_8(&adb->intr_enb.r, DFB | TAG);
printk("adb: mac-io driver 1.0 for unified ADB\n");
return 0;
}
static int macio_adb_autopoll(int devs)
{
out_8(&adb->active_hi.r, devs >> 8);
out_8(&adb->active_lo.r, devs);
out_8(&adb->autopoll.r, devs? APE: 0);
return 0;
}
static int macio_adb_reset_bus(void)
{
int timeout = 1000000;
out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST);
while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
if (--timeout == 0) {
out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
return -1;
}
}
return 0;
}
/* Send an ADB command */
static int macio_send_request(struct adb_request *req, int sync)
{
unsigned long mflags;
int i;
if (req->data[0] != ADB_PACKET)
return -EINVAL;
for (i = 0; i < req->nbytes - 1; ++i)
req->data[i] = req->data[i+1];
--req->nbytes;
req->next = 0;
req->sent = 0;
req->complete = 0;
req->reply_len = 0;
save_flags(mflags);
cli();
if (current_req != 0) {
last_req->next = req;
last_req = req;
} else {
current_req = last_req = req;
out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
}
restore_flags(mflags);
if (sync) {
while (!req->complete)
macio_adb_poll();
}
return 0;
}
static void macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs)
{
int i, n, err;
struct adb_request *req;
if (in_8(&adb->intr.r) & TAG) {
if ((req = current_req) != 0) {
/* put the current request in */
for (i = 0; i < req->nbytes; ++i)
out_8(&adb->data[i].r, req->data[i]);
out_8(&adb->dcount.r, req->nbytes & HMB);
req->sent = 1;
if (req->reply_expected) {
out_8(&adb->ctrl.r, DTB + CRE);
} else {
out_8(&adb->ctrl.r, DTB);
completed();
}
}
out_8(&adb->intr.r, 0);
}
if (in_8(&adb->intr.r) & DFB) {
err = in_8(&adb->error.r);
if (current_req && current_req->sent) {
/* this is the response to a command */
req = current_req;
if (err == 0) {
req->reply_len = in_8(&adb->dcount.r) & HMB;
for (i = 0; i < req->reply_len; ++i)
req->reply[i] = in_8(&adb->data[i].r);
}
completed();
} else if (err == 0) {
/* autopoll data */
n = in_8(&adb->dcount.r) & HMB;
for (i = 0; i < n; ++i)
adb_rbuf[i] = in_8(&adb->data[i].r);
adb_input(adb_rbuf, n, regs,
in_8(&adb->dcount.r) & APD);
}
out_8(&adb->error.r, 0);
out_8(&adb->intr.r, 0);
}
}
static void completed(void)
{
struct adb_request *req = current_req;
req->complete = 1;
current_req = req->next;
if (current_req)
out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
if (req->done)
(*req->done)(req);
}
static void macio_adb_poll(void)
{
unsigned long flags;
save_flags(flags);
cli();
if (in_8(&adb->intr.r) != 0)
macio_adb_interrupt(0, 0, 0);
restore_flags(flags);
}
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