patch-2.3.45 linux/drivers/macintosh/via-macii.c

• Lines: 680
• Date: Sun Feb 13 11:21:42 2000
• Orig file: v2.3.44/linux/drivers/macintosh/via-macii.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.44/linux/drivers/macintosh/via-macii.c linux/drivers/macintosh/via-macii.c
@@ -0,0 +1,679 @@
+/*
+ * Device driver for the via ADB on (many) Mac II-class machines
+ *
+ * Based on the original ADB keyboard handler Copyright (c) 1997 Alan Cox
+ * Also derived from code Copyright (C) 1996 Paul Mackerras.
+ *
+ * With various updates provided over the years by Michael Schmitz,
+ * Guideo Koerber and others.
+ *
+ * Rewrite for Unified ADB by Joshua M. Thompson ([email protected])
+ *
+ * 1999-08-02 (jmt) - Initial rewrite for Unified ADB.
+ */
+ 
+#include <stdarg.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 <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/machw.h>
+#include <asm/mac_via.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/init.h>
+
+static volatile unsigned char *via;
+
+/* 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) */
+#define ST_MASK		0x30		/* mask for selecting ADB state bits */
+
+/* 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 */
+#define SR_DATA		0x08		/* Shift register data */
+#define SR_CLOCK	0x10		/* Shift register clock */
+
+/* ADB transaction states according to GMHW */
+#define ST_CMD		0x00		/* ADB state: command byte */
+#define ST_EVEN		0x10		/* ADB state: even data byte */
+#define ST_ODD		0x20		/* ADB state: odd data byte */
+#define ST_IDLE		0x30		/* ADB state: idle, nothing to send */
+
+static int  macii_init_via(void);
+static void macii_start(void);
+static void macii_interrupt(int irq, void *arg, struct pt_regs *regs);
+static void macii_retransmit(int);
+static void macii_queue_poll(void);
+
+static int macii_probe(void);
+static int macii_init(void);
+static int macii_send_request(struct adb_request *req, int sync);
+static int macii_write(struct adb_request *req);
+static int macii_autopoll(int devs);
+static void macii_poll(void);
+static int macii_reset_bus(void);
+
+struct adb_driver via_macii_driver = {
+	"Mac II",
+	macii_probe,
+	macii_init,
+	macii_send_request,
+	macii_autopoll,
+	macii_poll,
+	macii_reset_bus
+};
+
+static enum macii_state {
+	idle,
+	sent_first_byte,
+	sending,
+	reading,
+	read_done,
+	awaiting_reply
+} macii_state;
+
+static int need_poll    = 0;
+static int command_byte = 0;
+static int last_reply   = 0;
+static int last_active  = 0;
+
+static struct adb_request *current_req;
+static struct adb_request *last_req;
+static struct adb_request *retry_req;
+static unsigned char reply_buf[16];
+static unsigned char *reply_ptr;
+static int reply_len;
+static int reading_reply;
+static int data_index;
+static int first_byte;
+static int prefix_len;
+static int status = ST_IDLE|TREQ;
+static int last_status;
+static int driver_running = 0;
+
+/* debug level 10 required for ADB logging (should be && debug_adb, ideally) */
+extern int console_loglevel;
+
+/* Check for MacII style ADB */
+static int macii_probe(void)
+{
+	if (macintosh_config->adb_type != MAC_ADB_II) return -ENODEV;
+
+	via = via1;
+
+	printk("adb: Mac II ADB Driver v0.4 for Unified ADB\n");
+	return 0;
+}
+
+/* Initialize the driver */
+int macii_init(void)
+{
+	unsigned long flags;
+	int err;
+	
+	save_flags(flags);
+	cli();
+	
+	err = macii_init_via();
+	if (err) return err;
+
+	err = request_irq(IRQ_MAC_ADB, macii_interrupt, IRQ_FLG_LOCK, "ADB",
+		    macii_interrupt);
+	if (err) return err;
+
+	macii_state = idle;
+	restore_flags(flags);	
+	return 0;
+}
+
+/* initialize the hardware */	
+static int macii_init_via(void)
+{
+	unsigned char x;
+
+	/* Set the lines up. We want TREQ as input TACK|TIP as output */
+	via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
+
+	/* Set up state: idle */
+	via[B] |= ST_IDLE;
+	last_status = via[B] & (ST_MASK|TREQ);
+
+	/* Shift register on input */
+	via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT;
+
+	/* Wipe any pending data and int */
+	x = via[SR];
+
+	return 0;
+}
+
+/* Send an ADB poll (Talk Register 0 command, tagged on the front of the request queue) */
+static void macii_queue_poll(void)
+{
+	static int device = 0;
+	static int in_poll=0;
+	static struct adb_request req;
+	unsigned long flags;
+
+	if (in_poll) printk("macii_queue_poll: double poll!\n");
+
+	in_poll++;
+	if (++device > 15) device = 1;
+
+	adb_request(&req, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1,
+		    ADB_READREG(device, 0));
+
+	save_flags(flags);
+	cli();
+
+	req.next = current_req;
+	current_req = &req;
+
+	restore_flags(flags);
+	macii_start();
+	in_poll--;
+}
+
+/* Send an ADB retransmit (Talk, appended to the request queue) */
+static void macii_retransmit(int device)
+{
+	static int in_retransmit = 0;
+	static struct adb_request rt;
+	unsigned long flags;
+
+	if (in_retransmit) printk("macii_retransmit: double retransmit!\n");
+
+	in_retransmit++;
+
+	adb_request(&rt, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1,
+		    ADB_READREG(device, 0));
+
+	save_flags(flags);
+	cli();
+
+	if (current_req != NULL) {
+		last_req->next = &rt;
+		last_req = &rt;
+	} else {
+		current_req = &rt;
+		last_req = &rt;
+	}
+
+	if (macii_state == idle) macii_start();
+
+	restore_flags(flags);
+	in_retransmit--;
+}
+
+/* Send an ADB request; if sync, poll out the reply 'till it's done */
+static int macii_send_request(struct adb_request *req, int sync)
+{
+	int i;
+
+	i = macii_write(req);
+	if (i) return i;
+
+	if (sync) {
+		while (!req->complete) macii_poll();
+	}
+	return 0;
+}
+
+/* Send an ADB request */
+static int macii_write(struct adb_request *req)
+{
+	unsigned long flags;
+
+	if (req->nbytes < 2 || req->data[0] != ADB_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 != NULL) {
+		last_req->next = req;
+		last_req = req;
+	} else {
+		current_req = req;
+		last_req = req;
+		if (macii_state == idle) macii_start();
+	}
+
+	restore_flags(flags);
+	return 0;
+}
+
+/* Start auto-polling */
+static int macii_autopoll(int devs)
+{
+	/* Just ping a random default address */
+	if (!(current_req || retry_req))
+		macii_retransmit( (last_active < 16 && last_active > 0) ? last_active : 3);
+	return 0;
+}
+
+/* Prod the chip without interrupts */
+static void macii_poll(void)
+{
+	unsigned long flags;
+
+	save_flags(flags); cli();
+	if (via[IFR] & SR_INT) macii_interrupt(0, 0, 0);
+	restore_flags(flags);
+}
+
+/* Reset the bus */
+static int macii_reset_bus(void)
+{
+	static struct adb_request req;
+	
+	/* Command = 0, Address = ignored */
+	adb_request(&req, NULL, 0, 1, ADB_BUSRESET);
+
+	return 0;
+}
+
+/* Start sending ADB packet */
+static void macii_start(void)
+{
+	unsigned long flags;
+	struct adb_request *req;
+
+	req = current_req;
+	if (!req) return;
+
+	/* assert macii_state == idle */
+	if (macii_state != idle) {
+		printk("macii_start: called while driver busy (%p %x %x)!\n",
+			req, macii_state, (uint) via1[B] & (ST_MASK|TREQ));
+		return;
+	}
+
+	save_flags(flags); cli();
+	
+	/* 
+	 * IRQ signaled ?? (means ADB controller wants to send, or might 
+	 * be end of packet if we were reading)
+	 */
+	if ((via[B] & TREQ) == 0) {
+		/*
+		 *	FIXME - we need to restart this on a timer
+		 *	or a collision at boot hangs us.
+		 *	Never set macii_state to idle here, or macii_start 
+		 *	won't be called again from send_request!
+		 *	(need to re-check other cases ...)
+		 */
+		/*
+		 * if the interrupt handler set the need_poll
+		 * flag, it's hopefully a SRQ poll or re-Talk
+		 * so we try to send here anyway
+		 */
+		if (!need_poll) {
+			if (console_loglevel == 10)
+				printk("macii_start: device busy - retry %p state %d status %x!\n", 
+					req, macii_state,
+					(uint) via[B] & (ST_MASK|TREQ));
+			retry_req = req;
+			/* set ADB status here ? */
+			restore_flags(flags);
+			return;
+		} else {
+			need_poll = 0;
+		}
+	}
+	/*
+	 * Another retry pending? (sanity check)
+	 */
+	if (retry_req) {
+		retry_req = NULL;
+	}
+
+	/* Now send it. Be careful though, that first byte of the request */
+	/* is actually ADB_PACKET; the real data begins at index 1!	  */
+
+	/* store command byte */
+	command_byte = req->data[1];
+	/* Output mode */
+	via[ACR] |= SR_OUT;
+	/* Load data */
+	via[SR] = req->data[1];
+	/* set ADB state to 'command' */
+	via[B] = (via[B] & ~ST_MASK) | ST_CMD;
+
+	macii_state = sent_first_byte;
+	data_index = 2;
+
+	restore_flags(flags);
+}
+
+/*
+ * The notorious ADB interrupt handler - does all of the protocol handling, 
+ * except for starting new send operations. Relies heavily on the ADB 
+ * controller sending and receiving data, thereby generating SR interrupts
+ * for us. This means there has to be always activity on the ADB bus, otherwise
+ * the whole process dies and has to be re-kicked by sending TALK requests ...
+ * CUDA-based Macs seem to solve this with the autopoll option, for MacII-type
+ * ADB the problem isn't solved yet (retransmit of the latest active TALK seems
+ * a good choice; either on timeout or on a timer interrupt).
+ *
+ * The basic ADB state machine was left unchanged from the original MacII code
+ * by Alan Cox, which was based on the CUDA driver for PowerMac. 
+ * The syntax of the ADB status lines seems to be totally different on MacII, 
+ * though. MacII uses the states Command -> Even -> Odd -> Even ->...-> Idle for
+ * sending, and Idle -> Even -> Odd -> Even ->...-> Idle for receiving. Start 
+ * and end of a receive packet are signaled by asserting /IRQ on the interrupt
+ * line. Timeouts are signaled by a sequence of 4 0xFF, with /IRQ asserted on 
+ * every other byte. SRQ is probably signaled by 3 or more 0xFF tacked on the 
+ * end of a packet. (Thanks to Guido Koerber for eavesdropping on the ADB 
+ * protocol with a logic analyzer!!)
+ *
+ * Note: As of 21/10/97, the MacII ADB part works including timeout detection
+ * and retransmit (Talk to the last active device).
+ */
+void macii_interrupt(int irq, void *arg, struct pt_regs *regs)
+{
+	int x, adbdir;
+	unsigned long flags;
+	struct adb_request *req;
+
+	last_status = status;
+
+	/* prevent races due to SCSI enabling ints */
+	save_flags(flags); cli();
+
+	if (driver_running) {
+		restore_flags(flags);
+		return;
+	}
+
+	driver_running = 1;
+	
+	status = via[B] & (ST_MASK|TREQ);
+	adbdir = via[ACR] & SR_OUT;
+
+	switch (macii_state) {
+		case idle:
+			x = via[SR];
+			first_byte = x;
+			/* set ADB state = even for first data byte */
+			via[B] = (via[B] & ~ST_MASK) | ST_EVEN;
+
+			reply_buf[0] = first_byte; /* was command_byte?? */
+			reply_ptr = reply_buf + 1;
+			reply_len = 1;
+			prefix_len = 1;
+			reading_reply = 0;
+
+			macii_state = reading;
+			break;
+
+		case awaiting_reply:
+			/* handshake etc. for II ?? */
+			x = via[SR];
+			first_byte = x;
+			/* set ADB state = even for first data byte */
+			via[B] = (via[B] & ~ST_MASK) | ST_EVEN;
+
+			current_req->reply[0] = first_byte;
+			reply_ptr = current_req->reply + 1;
+			reply_len = 1;
+			prefix_len = 1;
+			reading_reply = 1;
+
+			macii_state = reading;			
+			break;
+
+		case sent_first_byte:
+			req = current_req;
+			/* maybe we're already done (Talk, or Poll)? */
+			if (data_index >= req->nbytes) {
+				/* reset to shift in */
+				/* If it's a Listen command and we're done, someone's doing weird stuff. */
+				if (((command_byte & 0x0C) == 0x08)
+				    && (console_loglevel == 10))
+					printk("macii_interrupt: listen command with no data: %x!\n", 
+						command_byte);
+				/* reset to shift in */
+				via[ACR] &= ~SR_OUT;
+				x = via[SR];
+				/* set ADB state idle - might get SRQ */
+				via[B] = (via[B] & ~ST_MASK) | ST_IDLE;
+
+				req->sent = 1;
+
+				if (req->reply_expected) {
+					macii_state = awaiting_reply;
+				} else {
+					req->complete = 1;
+					current_req = req->next;
+					if (req->done) (*req->done)(req);
+					macii_state = idle;
+					if (current_req || retry_req)
+						macii_start();
+					else
+						macii_retransmit((command_byte & 0xF0) >> 4);
+				}
+			} else {
+				/* SR already set to shift out; send byte */
+				via[SR] = current_req->data[data_index++];
+				/* set state to ST_EVEN (first byte was: ST_CMD) */
+				via[B] = (via[B] & ~ST_MASK) | ST_EVEN;
+				macii_state = sending;
+			}
+			break;
+
+		case sending:
+			req = current_req;
+			if (data_index >= req->nbytes) {
+				/* reset to shift in */
+				via[ACR] &= ~SR_OUT;
+				x = via[SR];
+				/* set ADB state idle - might get SRQ */
+				via[B] = (via[B] & ~ST_MASK) | ST_IDLE;
+
+				req->sent = 1;
+
+				if (req->reply_expected) {
+					macii_state = awaiting_reply;
+				} else {
+					req->complete = 1;
+					current_req = req->next;
+					if (req->done) (*req->done)(req);
+					macii_state = idle;
+					if (current_req || retry_req)
+						macii_start();
+					else
+						macii_retransmit((command_byte & 0xF0) >> 4);
+				}
+			} else {
+				via[SR] = req->data[data_index++];
+
+				/* invert state bits, toggle ODD/EVEN */
+				via[B] ^= ST_MASK;
+			}
+			break;
+
+		case reading:
+
+			/* timeout / SRQ handling for II hw */
+			if( (first_byte == 0xFF && (reply_len-prefix_len)==2 
+			     && memcmp(reply_ptr-2,"\xFF\xFF",2)==0) || 
+			    ((reply_len-prefix_len)==3 
+			     && memcmp(reply_ptr-3,"\xFF\xFF\xFF",3)==0))
+			{
+				/*
+				 * possible timeout (in fact, most probably a 
+				 * timeout, since SRQ can't be signaled without
+				 * transfer on the bus).
+				 * The last three bytes seen were FF, together 
+				 * with the starting byte (in case we started
+				 * on 'idle' or 'awaiting_reply') this probably
+				 * makes four. So this is mostl likely #5!
+				 * The timeout signal is a pattern 1 0 1 0 0..
+				 * on /INT, meaning we missed it :-(
+				 */
+				x = via[SR];
+				if (x != 0xFF) printk("macii_interrupt: mistaken timeout/SRQ!\n");
+
+				if ((status & TREQ) == (last_status & TREQ)) {
+					/* Not a timeout. Unsolicited SRQ? weird. */
+					/* Terminate the SRQ packet and poll */
+					need_poll = 1;
+				}
+				/* There's no packet to get, so reply is blank */
+				via[B] ^= ST_MASK;
+				reply_ptr -= (reply_len-prefix_len);
+				reply_len = prefix_len;
+				macii_state = read_done;
+				break;
+			} /* end timeout / SRQ handling for II hw. */
+
+			if((reply_len-prefix_len)>3
+				&& memcmp(reply_ptr-3,"\xFF\xFF\xFF",3)==0)
+			{
+				/* SRQ tacked on data packet */
+				/* Terminate the packet (SRQ never ends) */
+				x = via[SR];
+				macii_state = read_done;
+				reply_len -= 3;
+				reply_ptr -= 3;
+				need_poll = 1;
+				/* need to continue; next byte not seen else */
+			} else {
+				/* Sanity check */
+				if (reply_len > 15) reply_len = 0;
+				/* read byte */
+				x = via[SR];
+				*reply_ptr = x;
+				reply_ptr++;
+				reply_len++;
+			}
+			/* The usual handshake ... */
+
+			/*
+			 * NetBSD hints that the next to last byte 
+			 * is sent with IRQ !! 
+			 * Guido found out it's the last one (0x0),
+			 * but IRQ should be asserted already.
+			 * Problem with timeout detection: First
+			 * transition to /IRQ might be second 
+			 * byte of timeout packet! 
+			 * Timeouts are signaled by 4x FF.
+			 */
+			if (!(status & TREQ) && (x == 0x00)) { /* != 0xFF */
+				/* invert state bits, toggle ODD/EVEN */
+				via[B] ^= ST_MASK;
+
+				/* adjust packet length */
+				reply_len--;
+				reply_ptr--;
+				macii_state = read_done;
+			} else {
+				/* not caught: ST_CMD */
+				/* required for re-entry 'reading'! */
+				if ((status & ST_MASK) == ST_IDLE) {
+					/* (in)sanity check - set even */
+					via[B] = (via[B] & ~ST_MASK) | ST_EVEN;
+				} else {
+					/* invert state bits */
+					via[B] ^= ST_MASK;
+				}
+			}
+			break;
+
+		case read_done:
+			x = via[SR];
+			if (reading_reply) {
+				req = current_req;
+				req->reply_len = reply_ptr - req->reply;
+				req->complete = 1;
+				current_req = req->next;
+				if (req->done) (*req->done)(req);
+			} else {
+				adb_input(reply_buf, reply_ptr - reply_buf,
+					  regs, 0);
+			}
+
+			/*
+			 * remember this device ID; it's the latest we got a 
+			 * reply from!
+			 */
+			last_reply = command_byte;
+			last_active = (command_byte & 0xF0) >> 4;
+
+			/* SRQ seen before, initiate poll now */
+			if (need_poll) {
+				macii_state = idle;
+				macii_queue_poll();
+				need_poll = 0;
+				break;
+			}
+
+			/* /IRQ seen, so the ADB controller has data for us */
+			if (!(status & TREQ)) {
+				/* set ADB state to idle */
+				via[B] = (via[B] & ~ST_MASK) | ST_IDLE;
+
+				macii_state = reading;
+
+				reply_buf[0] = command_byte;
+				reply_ptr = reply_buf + 1;
+				reply_len = 1;
+				prefix_len = 1;
+				reading_reply = 0;
+			} else {
+				/* no IRQ, send next packet or wait */
+				macii_state = idle;
+				if (current_req)
+					macii_start();
+				else
+					macii_retransmit(last_active);
+			}
+			break;
+
+		default:
+		break;
+	}
+	/* reset mutex and interrupts */
+	driver_running = 0;
+	restore_flags(flags);
+}