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-rw-r--r--drivers/macintosh/via-macii.c564
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diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c
new file mode 100644
index 0000000000..db9270da5b
--- /dev/null
+++ b/drivers/macintosh/via-macii.c
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+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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 (funaho@jurai.org)
+ *
+ * 1999-08-02 (jmt) - Initial rewrite for Unified ADB.
+ * 2000-03-29 Tony Mantler <tonym@mac.linux-m68k.org>
+ * - Big overhaul, should actually work now.
+ * 2006-12-31 Finn Thain - Another overhaul.
+ *
+ * Suggested reading:
+ * Inside Macintosh, ch. 5 ADB Manager
+ * Guide to the Macinstosh Family Hardware, ch. 8 Apple Desktop Bus
+ * Rockwell R6522 VIA datasheet
+ *
+ * Apple's "ADB Analyzer" bus sniffer is invaluable:
+ * ftp://ftp.apple.com/developer/Tool_Chest/Devices_-_Hardware/Apple_Desktop_Bus/
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/adb.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_via.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 CTLR_IRQ 0x08 /* Controller rcv status (input) */
+#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 */
+
+/* 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 */
+
+/* ADB command byte structure */
+#define ADDR_MASK 0xF0
+#define CMD_MASK 0x0F
+#define OP_MASK 0x0C
+#define TALK 0x0C
+
+static int macii_init_via(void);
+static void macii_start(void);
+static irqreturn_t macii_interrupt(int irq, void *arg);
+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 = {
+ .name = "Mac II",
+ .probe = macii_probe,
+ .init = macii_init,
+ .send_request = macii_send_request,
+ .autopoll = macii_autopoll,
+ .poll = macii_poll,
+ .reset_bus = macii_reset_bus,
+};
+
+static enum macii_state {
+ idle,
+ sending,
+ reading,
+} macii_state;
+
+static struct adb_request *current_req; /* first request struct in the queue */
+static struct adb_request *last_req; /* last request struct in the queue */
+static unsigned char reply_buf[16]; /* storage for autopolled replies */
+static unsigned char *reply_ptr; /* next byte in reply_buf or req->reply */
+static bool reading_reply; /* store reply in reply_buf else req->reply */
+static int data_index; /* index of the next byte to send from req->data */
+static int reply_len; /* number of bytes received in reply_buf or req->reply */
+static int status; /* VIA's ADB status bits captured upon interrupt */
+static bool bus_timeout; /* no data was sent by the device */
+static bool srq_asserted; /* have to poll for the device that asserted it */
+static u8 last_cmd; /* the most recent command byte transmitted */
+static u8 last_talk_cmd; /* the most recent Talk command byte transmitted */
+static u8 last_poll_cmd; /* the most recent Talk R0 command byte transmitted */
+static unsigned int autopoll_devs; /* bits set are device addresses to poll */
+
+/* Check for MacII style ADB */
+static int macii_probe(void)
+{
+ if (macintosh_config->adb_type != MAC_ADB_II)
+ return -ENODEV;
+
+ via = via1;
+
+ pr_info("adb: Mac II ADB Driver v1.0 for Unified ADB\n");
+ return 0;
+}
+
+/* Initialize the driver */
+static int macii_init(void)
+{
+ unsigned long flags;
+ int err;
+
+ local_irq_save(flags);
+
+ err = macii_init_via();
+ if (err)
+ goto out;
+
+ err = request_irq(IRQ_MAC_ADB, macii_interrupt, 0, "ADB",
+ macii_interrupt);
+ if (err)
+ goto out;
+
+ macii_state = idle;
+out:
+ local_irq_restore(flags);
+ return err;
+}
+
+/* initialize the hardware */
+static int macii_init_via(void)
+{
+ unsigned char x;
+
+ /* We want CTLR_IRQ as input and ST_EVEN | ST_ODD as output lines. */
+ via[DIRB] = (via[DIRB] | ST_EVEN | ST_ODD) & ~CTLR_IRQ;
+
+ /* Set up state: idle */
+ via[B] |= ST_IDLE;
+
+ /* 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 prepended to the request queue) */
+static void macii_queue_poll(void)
+{
+ static struct adb_request req;
+ unsigned char poll_command;
+ unsigned int poll_addr;
+
+ /* This only polls devices in the autopoll list, which assumes that
+ * unprobed devices never assert SRQ. That could happen if a device was
+ * plugged in after the adb bus scan. Unplugging it again will resolve
+ * the problem. This behaviour is similar to MacOS.
+ */
+ if (!autopoll_devs)
+ return;
+
+ /* The device most recently polled may not be the best device to poll
+ * right now. Some other device(s) may have signalled SRQ (the active
+ * device won't do that). Or the autopoll list may have been changed.
+ * Try polling the next higher address.
+ */
+ poll_addr = (last_poll_cmd & ADDR_MASK) >> 4;
+ if ((srq_asserted && last_cmd == last_poll_cmd) ||
+ !(autopoll_devs & (1 << poll_addr))) {
+ unsigned int higher_devs;
+
+ higher_devs = autopoll_devs & -(1 << (poll_addr + 1));
+ poll_addr = ffs(higher_devs ? higher_devs : autopoll_devs) - 1;
+ }
+
+ /* Send a Talk Register 0 command */
+ poll_command = ADB_READREG(poll_addr, 0);
+
+ /* No need to repeat this Talk command. The transceiver will do that
+ * as long as it is idle.
+ */
+ if (poll_command == last_cmd)
+ return;
+
+ adb_request(&req, NULL, ADBREQ_NOSEND, 1, poll_command);
+
+ req.sent = 0;
+ req.complete = 0;
+ req.reply_len = 0;
+ req.next = current_req;
+
+ if (WARN_ON(current_req)) {
+ current_req = &req;
+ } else {
+ current_req = &req;
+ last_req = &req;
+ }
+}
+
+/* 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 err;
+
+ err = macii_write(req);
+ if (err)
+ return err;
+
+ if (sync)
+ while (!req->complete)
+ macii_poll();
+
+ return 0;
+}
+
+/* Send an ADB request (append to request queue) */
+static int macii_write(struct adb_request *req)
+{
+ unsigned long flags;
+
+ if (req->nbytes < 2 || req->data[0] != ADB_PACKET || req->nbytes > 15) {
+ req->complete = 1;
+ return -EINVAL;
+ }
+
+ req->next = NULL;
+ req->sent = 0;
+ req->complete = 0;
+ req->reply_len = 0;
+
+ local_irq_save(flags);
+
+ if (current_req != NULL) {
+ last_req->next = req;
+ last_req = req;
+ } else {
+ current_req = req;
+ last_req = req;
+ if (macii_state == idle)
+ macii_start();
+ }
+
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+/* Start auto-polling */
+static int macii_autopoll(int devs)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ /* bit 1 == device 1, and so on. */
+ autopoll_devs = (unsigned int)devs & 0xFFFE;
+
+ if (!current_req) {
+ macii_queue_poll();
+ if (current_req && macii_state == idle)
+ macii_start();
+ }
+
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+/* Prod the chip without interrupts */
+static void macii_poll(void)
+{
+ macii_interrupt(0, NULL);
+}
+
+/* Reset the bus */
+static int macii_reset_bus(void)
+{
+ struct adb_request req;
+
+ /* Command = 0, Address = ignored */
+ adb_request(&req, NULL, ADBREQ_NOSEND, 1, ADB_BUSRESET);
+ macii_send_request(&req, 1);
+
+ /* Don't want any more requests during the Global Reset low time. */
+ udelay(3000);
+
+ return 0;
+}
+
+/* Start sending ADB packet */
+static void macii_start(void)
+{
+ struct adb_request *req;
+
+ req = current_req;
+
+ /* Now send it. Be careful though, that first byte of the request
+ * is actually ADB_PACKET; the real data begins at index 1!
+ * And req->nbytes is the number of bytes of real data plus one.
+ */
+
+ /* 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 = sending;
+ data_index = 2;
+
+ bus_timeout = false;
+ srq_asserted = false;
+}
+
+/*
+ * The notorious ADB interrupt handler - does all of the protocol handling.
+ * Relies on the ADB controller sending and receiving data, thereby
+ * generating shift register interrupts (SR_INT) for us. This means there has
+ * to be activity on the ADB bus. The chip will poll to achieve this.
+ *
+ * The VIA Port B output signalling works as follows. After the ADB transceiver
+ * sees a transition on the PB4 and PB5 lines it will crank over the VIA shift
+ * register which eventually raises the SR_INT interrupt. The PB4/PB5 outputs
+ * are toggled with each byte as the ADB transaction progresses.
+ *
+ * Request with no reply expected (and empty transceiver buffer):
+ * CMD -> IDLE
+ * Request with expected reply packet (or with buffered autopoll packet):
+ * CMD -> EVEN -> ODD -> EVEN -> ... -> IDLE
+ * Unsolicited packet:
+ * IDLE -> EVEN -> ODD -> EVEN -> ... -> IDLE
+ */
+static irqreturn_t macii_interrupt(int irq, void *arg)
+{
+ int x;
+ struct adb_request *req;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ if (!arg) {
+ /* Clear the SR IRQ flag when polling. */
+ if (via[IFR] & SR_INT)
+ via[IFR] = SR_INT;
+ else {
+ local_irq_restore(flags);
+ return IRQ_NONE;
+ }
+ }
+
+ status = via[B] & (ST_MASK | CTLR_IRQ);
+
+ switch (macii_state) {
+ case idle:
+ WARN_ON((status & ST_MASK) != ST_IDLE);
+
+ reply_ptr = reply_buf;
+ reading_reply = false;
+
+ bus_timeout = false;
+ srq_asserted = false;
+
+ x = via[SR];
+
+ if (!(status & CTLR_IRQ)) {
+ /* /CTLR_IRQ asserted in idle state means we must
+ * read an autopoll reply from the transceiver buffer.
+ */
+ macii_state = reading;
+ *reply_ptr = x;
+ reply_len = 1;
+ } else {
+ /* bus timeout */
+ reply_len = 0;
+ break;
+ }
+
+ /* set ADB state = even for first data byte */
+ via[B] = (via[B] & ~ST_MASK) | ST_EVEN;
+ break;
+
+ case sending:
+ req = current_req;
+
+ if (status == (ST_CMD | CTLR_IRQ)) {
+ /* /CTLR_IRQ de-asserted after the command byte means
+ * the host can continue with the transaction.
+ */
+
+ /* Store command byte */
+ last_cmd = req->data[1];
+ if ((last_cmd & OP_MASK) == TALK) {
+ last_talk_cmd = last_cmd;
+ if ((last_cmd & CMD_MASK) == ADB_READREG(0, 0))
+ last_poll_cmd = last_cmd;
+ }
+ }
+
+ if (status == ST_CMD) {
+ /* /CTLR_IRQ asserted after the command byte means we
+ * must read an autopoll reply. The first byte was
+ * lost because the shift register was an output.
+ */
+ macii_state = reading;
+
+ reading_reply = false;
+ reply_ptr = reply_buf;
+ *reply_ptr = last_talk_cmd;
+ reply_len = 1;
+
+ /* reset to shift in */
+ via[ACR] &= ~SR_OUT;
+ x = via[SR];
+ } else if (data_index >= req->nbytes) {
+ req->sent = 1;
+
+ if (req->reply_expected) {
+ macii_state = reading;
+
+ reading_reply = true;
+ reply_ptr = req->reply;
+ *reply_ptr = req->data[1];
+ reply_len = 1;
+
+ via[ACR] &= ~SR_OUT;
+ x = via[SR];
+ } else if ((req->data[1] & OP_MASK) == TALK) {
+ macii_state = reading;
+
+ reading_reply = false;
+ reply_ptr = reply_buf;
+ *reply_ptr = req->data[1];
+ reply_len = 1;
+
+ via[ACR] &= ~SR_OUT;
+ x = via[SR];
+
+ req->complete = 1;
+ current_req = req->next;
+ if (req->done)
+ (*req->done)(req);
+ } else {
+ macii_state = idle;
+
+ req->complete = 1;
+ current_req = req->next;
+ if (req->done)
+ (*req->done)(req);
+ break;
+ }
+ } else {
+ via[SR] = req->data[data_index++];
+ }
+
+ if ((via[B] & ST_MASK) == ST_CMD) {
+ /* just sent the command byte, set to EVEN */
+ via[B] = (via[B] & ~ST_MASK) | ST_EVEN;
+ } else {
+ /* invert state bits, toggle ODD/EVEN */
+ via[B] ^= ST_MASK;
+ }
+ break;
+
+ case reading:
+ x = via[SR];
+ WARN_ON((status & ST_MASK) == ST_CMD ||
+ (status & ST_MASK) == ST_IDLE);
+
+ if (!(status & CTLR_IRQ)) {
+ if (status == ST_EVEN && reply_len == 1) {
+ bus_timeout = true;
+ } else if (status == ST_ODD && reply_len == 2) {
+ srq_asserted = true;
+ } else {
+ macii_state = idle;
+
+ if (bus_timeout)
+ reply_len = 0;
+
+ if (reading_reply) {
+ struct adb_request *req = current_req;
+
+ req->reply_len = reply_len;
+
+ req->complete = 1;
+ current_req = req->next;
+ if (req->done)
+ (*req->done)(req);
+ } else if (reply_len && autopoll_devs &&
+ reply_buf[0] == last_poll_cmd) {
+ adb_input(reply_buf, reply_len, 1);
+ }
+ break;
+ }
+ }
+
+ if (reply_len < ARRAY_SIZE(reply_buf)) {
+ reply_ptr++;
+ *reply_ptr = x;
+ reply_len++;
+ }
+
+ /* invert state bits, toggle ODD/EVEN */
+ via[B] ^= ST_MASK;
+ break;
+
+ default:
+ break;
+ }
+
+ if (macii_state == idle) {
+ if (!current_req)
+ macii_queue_poll();
+
+ if (current_req)
+ macii_start();
+
+ if (macii_state == idle) {
+ via[ACR] &= ~SR_OUT;
+ x = via[SR];
+ via[B] = (via[B] & ~ST_MASK) | ST_IDLE;
+ }
+ }
+
+ local_irq_restore(flags);
+ return IRQ_HANDLED;
+}
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