--- /dev/null
+/*
+ * 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/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/adb.h>
+#include <linux/cuda.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#ifdef CONFIG_PPC
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#else
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_via.h>
+#endif
+#include <asm/io.h>
+#include <linux/init.h>
+
+static volatile unsigned char __iomem *via;
+static DEFINE_SPINLOCK(cuda_lock);
+
+/* 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;
+static int cuda_irq;
+#ifdef CONFIG_PPC
+static struct device_node *vias;
+#endif
+static int cuda_fully_inited;
+
+#ifdef CONFIG_ADB
+static int cuda_probe(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 irqreturn_t cuda_interrupt(int irq, void *arg);
+static void cuda_input(unsigned char *buf, int nb);
+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 = {
+ .name = "CUDA",
+ .probe = cuda_probe,
+ .send_request = cuda_send_request,
+ .autopoll = cuda_adb_autopoll,
+ .poll = cuda_poll,
+ .reset_bus = cuda_reset_adb_bus,
+};
+#endif /* CONFIG_ADB */
+
+#ifdef CONFIG_MAC
+int __init find_via_cuda(void)
+{
+ struct adb_request req;
+ int err;
+
+ if (macintosh_config->adb_type != MAC_ADB_CUDA)
+ return 0;
+
+ via = via1;
+ cuda_state = idle;
+
+ err = cuda_init_via();
+ if (err) {
+ printk(KERN_ERR "cuda_init_via() failed\n");
+ via = NULL;
+ return 0;
+ }
+
+ /* enable autopoll */
+ cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
+ while (!req.complete)
+ cuda_poll();
+
+ return 1;
+}
+#else
+int __init find_via_cuda(void)
+{
+ struct adb_request req;
+ phys_addr_t taddr;
+ const u32 *reg;
+ int err;
+
+ if (vias != 0)
+ return 1;
+ vias = of_find_node_by_name(NULL, "via-cuda");
+ if (vias == 0)
+ return 0;
+
+ reg = of_get_property(vias, "reg", NULL);
+ if (reg == NULL) {
+ printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
+ goto fail;
+ }
+ taddr = of_translate_address(vias, reg);
+ if (taddr == 0) {
+ printk(KERN_ERR "via-cuda: Can't translate address !\n");
+ goto fail;
+ }
+ via = ioremap(taddr, 0x2000);
+ if (via == NULL) {
+ printk(KERN_ERR "via-cuda: Can't map address !\n");
+ goto fail;
+ }
+
+ 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 */
+
+ out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */
+ out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
+
+ /* enable autopoll */
+ cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
+ while (!req.complete)
+ cuda_poll();
+
+ return 1;
+
+ fail:
+ of_node_put(vias);
+ vias = NULL;
+ return 0;
+}
+#endif /* !defined CONFIG_MAC */
+
+static int __init via_cuda_start(void)
+{
+ if (via == NULL)
+ return -ENODEV;
+
+#ifdef CONFIG_MAC
+ cuda_irq = IRQ_MAC_ADB;
+#else
+ cuda_irq = irq_of_parse_and_map(vias, 0);
+ if (cuda_irq == NO_IRQ) {
+ printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
+ vias->full_name);
+ return -ENODEV;
+ }
+#endif
+
+ if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
+ printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
+ return -EAGAIN;
+ }
+
+ printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
+
+ cuda_fully_inited = 1;
+ return 0;
+}
+
+device_initcall(via_cuda_start);
+
+#ifdef CONFIG_ADB
+static int
+cuda_probe(void)
+{
+#ifdef CONFIG_PPC
+ if (sys_ctrler != SYS_CTRLER_CUDA)
+ return -ENODEV;
+#else
+ if (macintosh_config->adb_type != MAC_ADB_CUDA)
+ return -ENODEV;
+#endif
+ if (via == NULL)
+ return -ENODEV;
+ return 0;
+}
+#endif /* CONFIG_ADB */
+
+#define WAIT_FOR(cond, what) \
+ do { \
+ int x; \
+ for (x = 1000; !(cond); --x) { \
+ if (x == 0) { \
+ printk("Timeout waiting for " what "\n"); \
+ return -ENXIO; \
+ } \
+ udelay(100); \
+ } \
+ } while (0)
+
+static int
+__init cuda_init_via(void)
+{
+ out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
+ out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */
+ out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
+ (void)in_8(&via[SR]); /* clear any left-over data */
+#ifdef CONFIG_PPC
+ out_8(&via[IER], 0x7f); /* disable interrupts from VIA */
+ (void)in_8(&via[IER]);
+#else
+ out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */
+#endif
+
+ /* delay 4ms and then clear any pending interrupt */
+ mdelay(4);
+ (void)in_8(&via[SR]);
+ out_8(&via[IFR], SR_INT);
+
+ /* sync with the CUDA - assert TACK without TIP */
+ out_8(&via[B], in_8(&via[B]) & ~TACK);
+
+ /* wait for the CUDA to assert TREQ in response */
+ WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
+
+ /* wait for the interrupt and then clear it */
+ WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
+ (void)in_8(&via[SR]);
+ out_8(&via[IFR], SR_INT);
+
+ /* finish the sync by negating TACK */
+ out_8(&via[B], in_8(&via[B]) | TACK);
+
+ /* wait for the CUDA to negate TREQ and the corresponding interrupt */
+ WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
+ WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
+ (void)in_8(&via[SR]);
+ out_8(&via[IFR], SR_INT);
+ out_8(&via[B], in_8(&via[B]) | TIP); /* 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);
+}
+EXPORT_SYMBOL(cuda_request);
+
+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 = NULL;
+ req->sent = 0;
+ req->complete = 0;
+ req->reply_len = 0;
+
+ spin_lock_irqsave(&cuda_lock, flags);
+ if (current_req != 0) {
+ last_req->next = req;
+ last_req = req;
+ } else {
+ current_req = req;
+ last_req = req;
+ if (cuda_state == idle)
+ cuda_start();
+ }
+ spin_unlock_irqrestore(&cuda_lock, flags);
+
+ return 0;
+}
+
+static void
+cuda_start(void)
+{
+ struct adb_request *req;
+
+ /* assert cuda_state == idle */
+ /* get the packet to send */
+ req = current_req;
+ if (req == 0)
+ return;
+ if ((in_8(&via[B]) & TREQ) == 0)
+ return; /* a byte is coming in from the CUDA */
+
+ /* set the shift register to shift out and send a byte */
+ out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
+ out_8(&via[SR], req->data[0]);
+ out_8(&via[B], in_8(&via[B]) & ~TIP);
+ cuda_state = sent_first_byte;
+}
+
+void
+cuda_poll(void)
+{
+ /* cuda_interrupt only takes a normal lock, we disable
+ * interrupts here to avoid re-entering and thus deadlocking.
+ */
+ if (cuda_irq)
+ disable_irq(cuda_irq);
+ cuda_interrupt(0, NULL);
+ if (cuda_irq)
+ enable_irq(cuda_irq);
+}
+EXPORT_SYMBOL(cuda_poll);
+
+static irqreturn_t
+cuda_interrupt(int irq, void *arg)
+{
+ int status;
+ struct adb_request *req = NULL;
+ unsigned char ibuf[16];
+ int ibuf_len = 0;
+ int complete = 0;
+
+ spin_lock(&cuda_lock);
+
+ /* On powermacs, this handler is registered for the VIA IRQ. But they use
+ * just the shift register IRQ -- other VIA interrupt sources are disabled.
+ * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
+ * we are polling, the shift register IRQ flag has already been cleared.
+ */
+
+#ifdef CONFIG_MAC
+ if (!arg)
+#endif
+ {
+ if ((in_8(&via[IFR]) & SR_INT) == 0) {
+ spin_unlock(&cuda_lock);
+ return IRQ_NONE;
+ } else {
+ out_8(&via[IFR], SR_INT);
+ }
+ }
+
+ status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
+ /* 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);
+ (void)in_8(&via[SR]);
+ out_8(&via[B], in_8(&via[B]) & ~TIP);
+ 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);
+ (void)in_8(&via[SR]);
+ out_8(&via[B], in_8(&via[B]) & ~TIP);
+ cuda_state = reading;
+ reply_ptr = current_req->reply;
+ reading_reply = 1;
+ break;
+
+ case sent_first_byte:
+ if (status == TREQ + TIP + SR_OUT) {
+ /* collision */
+ out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
+ (void)in_8(&via[SR]);
+ out_8(&via[B], in_8(&via[B]) | TIP | TACK);
+ cuda_state = idle;
+ } else {
+ /* assert status == TIP + SR_OUT */
+ if (status != TIP + SR_OUT)
+ printk("cuda: state=sent_first_byte status=%x\n", status);
+ out_8(&via[SR], current_req->data[1]);
+ out_8(&via[B], in_8(&via[B]) ^ TACK);
+ data_index = 2;
+ cuda_state = sending;
+ }
+ break;
+
+ case sending:
+ req = current_req;
+ if (data_index >= req->nbytes) {
+ out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
+ (void)in_8(&via[SR]);
+ out_8(&via[B], in_8(&via[B]) | TACK | TIP);
+ req->sent = 1;
+ if (req->reply_expected) {
+ cuda_state = awaiting_reply;
+ } else {
+ current_req = req->next;
+ complete = 1;
+ /* not sure about this */
+ cuda_state = idle;
+ cuda_start();
+ }
+ } else {
+ out_8(&via[SR], req->data[data_index++]);
+ out_8(&via[B], in_8(&via[B]) ^ TACK);
+ }
+ break;
+
+ case reading:
+ *reply_ptr++ = in_8(&via[SR]);
+ if (status == TIP) {
+ /* that's all folks */
+ out_8(&via[B], in_8(&via[B]) | TACK | TIP);
+ cuda_state = read_done;
+ } else {
+ /* assert status == TIP | TREQ */
+ if (status != TIP + TREQ)
+ printk("cuda: state=reading status=%x\n", status);
+ out_8(&via[B], in_8(&via[B]) ^ TACK);
+ }
+ break;
+
+ case read_done:
+ (void)in_8(&via[SR]);
+ 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);
+ }
+ }
+ current_req = req->next;
+ complete = 1;
+ } else {
+ /* This is tricky. We must break the spinlock to call
+ * cuda_input. However, doing so means we might get
+ * re-entered from another CPU getting an interrupt
+ * or calling cuda_poll(). I ended up using the stack
+ * (it's only for 16 bytes) and moving the actual
+ * call to cuda_input to outside of the lock.
+ */
+ ibuf_len = reply_ptr - cuda_rbuf;
+ memcpy(ibuf, cuda_rbuf, ibuf_len);
+ }
+ if (status == TREQ) {
+ out_8(&via[B], in_8(&via[B]) & ~TIP);
+ 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);
+ }
+ spin_unlock(&cuda_lock);
+ if (complete && req) {
+ void (*done)(struct adb_request *) = req->done;
+ mb();
+ req->complete = 1;
+ /* Here, we assume that if the request has a done member, the
+ * struct request will survive to setting req->complete to 1
+ */
+ if (done)
+ (*done)(req);
+ }
+ if (ibuf_len)
+ cuda_input(ibuf, ibuf_len);
+ return IRQ_HANDLED;
+}
+
+static void
+cuda_input(unsigned char *buf, int nb)
+{
+ 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, 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");
+ }
+}
Code Review / kvmfornfv.git / blobdiff