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/*
* Device driver for the via-cuda on Apple Powermacs.
*
* The VIA (versatile interface adapter) interfaces to the CUDA,
* a 6805 microprocessor core which controls the ADB (Apple Desktop
* Bus) which connects to the keyboard and mouse. The CUDA also
* controls system power and the RTC (real time clock) chip.
*
* Copyright (C) 1996 Paul Mackerras.
*/
#include <stdarg.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#ifdef CONFIG_PPC
#include <asm/prom.h>
#include <asm/machdep.h>
#else
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>
#endif
#include <asm/io.h>
#include <asm/system.h>
#include <linux/init.h>
static volatile unsigned char *via;
#ifdef CONFIG_MAC
#define CUDA_IRQ IRQ_MAC_ADB
#define __openfirmware
#define eieio()
#else
#define CUDA_IRQ vias->intrs[0].line
#endif
/* VIA registers - spaced 0x200 bytes apart */
#define RS 0x200 /* skip between registers */
#define B 0 /* B-side data */
#define A RS /* A-side data */
#define DIRB (2*RS) /* B-side direction (1=output) */
#define DIRA (3*RS) /* A-side direction (1=output) */
#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
#define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */
#define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */
#define SR (10*RS) /* Shift register */
#define ACR (11*RS) /* Auxiliary control register */
#define PCR (12*RS) /* Peripheral control register */
#define IFR (13*RS) /* Interrupt flag register */
#define IER (14*RS) /* Interrupt enable register */
#define ANH (15*RS) /* A-side data, no handshake */
/* Bits in B data register: all active low */
#define TREQ 0x08 /* Transfer request (input) */
#define TACK 0x10 /* Transfer acknowledge (output) */
#define TIP 0x20 /* Transfer in progress (output) */
/* Bits in ACR */
#define SR_CTRL 0x1c /* Shift register control bits */
#define SR_EXT 0x0c /* Shift on external clock */
#define SR_OUT 0x10 /* Shift out if 1 */
/* Bits in IFR and IER */
#define IER_SET 0x80 /* set bits in IER */
#define IER_CLR 0 /* clear bits in IER */
#define SR_INT 0x04 /* Shift register full/empty */
static enum cuda_state {
idle,
sent_first_byte,
sending,
reading,
read_done,
awaiting_reply
} cuda_state;
static struct adb_request *current_req;
static struct adb_request *last_req;
static unsigned char cuda_rbuf[16];
static unsigned char *reply_ptr;
static int reading_reply;
static int data_index;
#ifdef CONFIG_PPC
static struct device_node *vias;
#endif
static int cuda_fully_inited = 0;
#ifdef CONFIG_ADB
static int cuda_probe(void);
static int cuda_init(void);
static int cuda_send_request(struct adb_request *req, int sync);
static int cuda_adb_autopoll(int devs);
static int cuda_reset_adb_bus(void);
#endif /* CONFIG_ADB */
static int cuda_init_via(void);
static void cuda_start(void);
static void cuda_interrupt(int irq, void *arg, struct pt_regs *regs);
static void cuda_input(unsigned char *buf, int nb, struct pt_regs *regs);
void cuda_poll(void);
static int cuda_write(struct adb_request *req);
int cuda_request(struct adb_request *req,
void (*done)(struct adb_request *), int nbytes, ...);
#ifdef CONFIG_ADB
struct adb_driver via_cuda_driver = {
"CUDA",
cuda_probe,
cuda_init,
cuda_send_request,
cuda_adb_autopoll,
cuda_poll,
cuda_reset_adb_bus
};
#endif /* CONFIG_ADB */
#ifdef CONFIG_PPC
int
find_via_cuda(void)
{
int err;
struct adb_request req;
if (vias != 0)
return 1;
vias = find_devices("via-cuda");
if (vias == 0)
return 0;
if (vias->next != 0)
printk(KERN_WARNING "Warning: only using 1st via-cuda\n");
#if 0
{ int i;
printk("find_via_cuda: node = %p, addrs =", vias->node);
for (i = 0; i < vias->n_addrs; ++i)
printk(" %x(%x)", vias->addrs[i].address, vias->addrs[i].size);
printk(", intrs =");
for (i = 0; i < vias->n_intrs; ++i)
printk(" %x", vias->intrs[i].line);
printk("\n"); }
#endif
if (vias->n_addrs != 1 || vias->n_intrs != 1) {
printk(KERN_ERR "via-cuda: expecting 1 address (%d) and 1 interrupt (%d)\n",
vias->n_addrs, vias->n_intrs);
if (vias->n_addrs < 1 || vias->n_intrs < 1)
return 0;
}
via = (volatile unsigned char *) ioremap(vias->addrs->address, 0x2000);
cuda_state = idle;
sys_ctrler = SYS_CTRLER_CUDA;
err = cuda_init_via();
if (err) {
printk(KERN_ERR "cuda_init_via() failed\n");
via = NULL;
return 0;
}
/* Clear and enable interrupts, but only on PPC. On 68K it's done */
/* for us by the main VIA driver in arch/m68k/mac/via.c */
#ifndef CONFIG_MAC
via[IFR] = 0x7f; eieio(); /* clear interrupts by writing 1s */
via[IER] = IER_SET|SR_INT; eieio(); /* enable interrupt from SR */
#endif
/* enable autopoll */
cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
while (!req.complete)
cuda_poll();
return 1;
}
#endif /* CONFIG_PPC */
int via_cuda_start(void)
{
if (via == NULL)
return -ENODEV;
request_OF_resource(vias, 0, NULL);
if (request_irq(CUDA_IRQ, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
printk(KERN_ERR "cuda_init: can't get irq %d\n", CUDA_IRQ);
return -EAGAIN;
}
printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
cuda_fully_inited = 1;
return 0;
}
#ifdef CONFIG_ADB
static int
cuda_probe()
{
#ifdef CONFIG_PPC
if (sys_ctrler != SYS_CTRLER_CUDA)
return -ENODEV;
#else
if (macintosh_config->adb_type != MAC_ADB_CUDA)
return -ENODEV;
via = via1;
#endif
return 0;
}
static int
cuda_init(void)
{
if (via == NULL)
return -ENODEV;
#ifndef CONFIG_PPC
return via_cuda_start();
#endif
return 0;
}
#endif /* CONFIG_ADB */
#define WAIT_FOR(cond, what) \
do { \
for (x = 1000; !(cond); --x) { \
if (x == 0) { \
printk("Timeout waiting for " what "\n"); \
return -ENXIO; \
} \
udelay(100); \
} \
} while (0)
static int
cuda_init_via()
{
int x;
via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ; /* TACK & TIP out */
via[B] |= TACK | TIP; /* negate them */
via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT; /* SR data in */
eieio();
x = via[SR]; eieio(); /* clear any left-over data */
#ifndef CONFIG_MAC
via[IER] = 0x7f; eieio(); /* disable interrupts from VIA */
#endif
eieio();
/* delay 4ms and then clear any pending interrupt */
mdelay(4);
x = via[SR]; eieio();
/* sync with the CUDA - assert TACK without TIP */
via[B] &= ~TACK; eieio();
/* wait for the CUDA to assert TREQ in response */
WAIT_FOR((via[B] & TREQ) == 0, "CUDA response to sync");
/* wait for the interrupt and then clear it */
WAIT_FOR(via[IFR] & SR_INT, "CUDA response to sync (2)");
x = via[SR]; eieio();
/* finish the sync by negating TACK */
via[B] |= TACK; eieio();
/* wait for the CUDA to negate TREQ and the corresponding interrupt */
WAIT_FOR(via[B] & TREQ, "CUDA response to sync (3)");
WAIT_FOR(via[IFR] & SR_INT, "CUDA response to sync (4)");
x = via[SR]; eieio();
via[B] |= TIP; eieio(); /* should be unnecessary */
return 0;
}
#ifdef CONFIG_ADB
/* Send an ADB command */
static int
cuda_send_request(struct adb_request *req, int sync)
{
int i;
if ((via == NULL) || !cuda_fully_inited) {
req->complete = 1;
return -ENXIO;
}
req->reply_expected = 1;
i = cuda_write(req);
if (i)
return i;
if (sync) {
while (!req->complete)
cuda_poll();
}
return 0;
}
/* Enable/disable autopolling */
static int
cuda_adb_autopoll(int devs)
{
struct adb_request req;
if ((via == NULL) || !cuda_fully_inited)
return -ENXIO;
cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
while (!req.complete)
cuda_poll();
return 0;
}
/* Reset adb bus - how do we do this?? */
static int
cuda_reset_adb_bus(void)
{
struct adb_request req;
if ((via == NULL) || !cuda_fully_inited)
return -ENXIO;
cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */
while (!req.complete)
cuda_poll();
return 0;
}
#endif /* CONFIG_ADB */
/* Construct and send a cuda request */
int
cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
int nbytes, ...)
{
va_list list;
int i;
if (via == NULL) {
req->complete = 1;
return -ENXIO;
}
req->nbytes = nbytes;
req->done = done;
va_start(list, nbytes);
for (i = 0; i < nbytes; ++i)
req->data[i] = va_arg(list, int);
va_end(list);
req->reply_expected = 1;
return cuda_write(req);
}
static int
cuda_write(struct adb_request *req)
{
unsigned long flags;
if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
req->complete = 1;
return -EINVAL;
}
req->next = 0;
req->sent = 0;
req->complete = 0;
req->reply_len = 0;
save_flags(flags); cli();
if (current_req != 0) {
last_req->next = req;
last_req = req;
} else {
current_req = req;
last_req = req;
if (cuda_state == idle)
cuda_start();
}
restore_flags(flags);
return 0;
}
static void
cuda_start()
{
unsigned long flags;
struct adb_request *req;
/* assert cuda_state == idle */
/* get the packet to send */
req = current_req;
if (req == 0)
return;
save_flags(flags); cli();
if ((via[B] & TREQ) == 0) {
restore_flags(flags);
return; /* a byte is coming in from the CUDA */
}
/* set the shift register to shift out and send a byte */
via[ACR] |= SR_OUT; eieio();
via[SR] = req->data[0]; eieio();
via[B] &= ~TIP;
cuda_state = sent_first_byte;
restore_flags(flags);
}
void
cuda_poll()
{
unsigned long flags;
save_flags(flags);
cli();
if (via[IFR] & SR_INT)
cuda_interrupt(0, 0, 0);
restore_flags(flags);
}
static void
cuda_interrupt(int irq, void *arg, struct pt_regs *regs)
{
int x, status;
struct adb_request *req;
if ((via[IFR] & SR_INT) == 0)
return;
status = (~via[B] & (TIP|TREQ)) | (via[ACR] & SR_OUT); eieio();
/* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
switch (cuda_state) {
case idle:
/* CUDA has sent us the first byte of data - unsolicited */
if (status != TREQ)
printk("cuda: state=idle, status=%x\n", status);
x = via[SR]; eieio();
via[B] &= ~TIP; eieio();
cuda_state = reading;
reply_ptr = cuda_rbuf;
reading_reply = 0;
break;
case awaiting_reply:
/* CUDA has sent us the first byte of data of a reply */
if (status != TREQ)
printk("cuda: state=awaiting_reply, status=%x\n", status);
x = via[SR]; eieio();
via[B] &= ~TIP; eieio();
cuda_state = reading;
reply_ptr = current_req->reply;
reading_reply = 1;
break;
case sent_first_byte:
if (status == TREQ + TIP + SR_OUT) {
/* collision */
via[ACR] &= ~SR_OUT; eieio();
x = via[SR]; eieio();
via[B] |= TIP | TACK; eieio();
cuda_state = idle;
} else {
/* assert status == TIP + SR_OUT */
if (status != TIP + SR_OUT)
printk("cuda: state=sent_first_byte status=%x\n", status);
via[SR] = current_req->data[1]; eieio();
via[B] ^= TACK; eieio();
data_index = 2;
cuda_state = sending;
}
break;
case sending:
req = current_req;
if (data_index >= req->nbytes) {
via[ACR] &= ~SR_OUT; eieio();
x = via[SR]; eieio();
via[B] |= TACK | TIP; eieio();
req->sent = 1;
if (req->reply_expected) {
cuda_state = awaiting_reply;
} else {
current_req = req->next;
if (req->done)
(*req->done)(req);
/* not sure about this */
cuda_state = idle;
cuda_start();
}
} else {
via[SR] = req->data[data_index++]; eieio();
via[B] ^= TACK; eieio();
}
break;
case reading:
*reply_ptr++ = via[SR]; eieio();
if (status == TIP) {
/* that's all folks */
via[B] |= TACK | TIP; eieio();
cuda_state = read_done;
} else {
/* assert status == TIP | TREQ */
if (status != TIP + TREQ)
printk("cuda: state=reading status=%x\n", status);
via[B] ^= TACK; eieio();
}
break;
case read_done:
x = via[SR]; eieio();
if (reading_reply) {
req = current_req;
req->reply_len = reply_ptr - req->reply;
if (req->data[0] == ADB_PACKET) {
/* Have to adjust the reply from ADB commands */
if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
/* the 0x2 bit indicates no response */
req->reply_len = 0;
} else {
/* leave just the command and result bytes in the reply */
req->reply_len -= 2;
memmove(req->reply, req->reply + 2, req->reply_len);
}
}
req->complete = 1;
current_req = req->next;
if (req->done)
(*req->done)(req);
} else {
cuda_input(cuda_rbuf, reply_ptr - cuda_rbuf, regs);
}
if (status == TREQ) {
via[B] &= ~TIP; eieio();
cuda_state = reading;
reply_ptr = cuda_rbuf;
reading_reply = 0;
} else {
cuda_state = idle;
cuda_start();
}
break;
default:
printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
}
}
static void
cuda_input(unsigned char *buf, int nb, struct pt_regs *regs)
{
int i;
switch (buf[0]) {
case ADB_PACKET:
#ifdef CONFIG_XMON
if (nb == 5 && buf[2] == 0x2c) {
extern int xmon_wants_key, xmon_adb_keycode;
if (xmon_wants_key) {
xmon_adb_keycode = buf[3];
return;
}
}
#endif /* CONFIG_XMON */
#ifdef CONFIG_ADB
adb_input(buf+2, nb-2, regs, buf[1] & 0x40);
#endif /* CONFIG_ADB */
break;
default:
printk("data from cuda (%d bytes):", nb);
for (i = 0; i < nb; ++i)
printk(" %.2x", buf[i]);
printk("\n");
}
}
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