summaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/macio-adb.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/macintosh/macio-adb.c')
-rw-r--r--drivers/macintosh/macio-adb.c291
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/macintosh/macio-adb.c b/drivers/macintosh/macio-adb.c
new file mode 100644
index 0000000000..55a9f8c3a1
--- /dev/null
+++ b/drivers/macintosh/macio-adb.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the ADB controller in the Mac I/O (Hydra) chip.
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/pgtable.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/adb.h>
+
+#include <asm/io.h>
+#include <asm/hydra.h>
+#include <asm/irq.h>
+#include <linux/init.h>
+#include <linux/ioport.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 __iomem *adb;
+static struct adb_request *current_req, *last_req;
+static DEFINE_SPINLOCK(macio_lock);
+
+static int macio_probe(void);
+static int macio_init(void);
+static irqreturn_t macio_adb_interrupt(int irq, void *arg);
+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);
+
+struct adb_driver macio_adb_driver = {
+ .name = "MACIO",
+ .probe = macio_probe,
+ .init = macio_init,
+ .send_request = macio_send_request,
+ .autopoll = macio_adb_autopoll,
+ .poll = macio_adb_poll,
+ .reset_bus = macio_adb_reset_bus,
+};
+
+int macio_probe(void)
+{
+ struct device_node *np;
+
+ np = of_find_compatible_node(NULL, "adb", "chrp,adb0");
+ if (np) {
+ of_node_put(np);
+ return 0;
+ }
+ return -ENODEV;
+}
+
+int macio_init(void)
+{
+ struct device_node *adbs;
+ struct resource r;
+ unsigned int irq;
+
+ adbs = of_find_compatible_node(NULL, "adb", "chrp,adb0");
+ if (!adbs)
+ return -ENXIO;
+
+ if (of_address_to_resource(adbs, 0, &r)) {
+ of_node_put(adbs);
+ return -ENXIO;
+ }
+ adb = ioremap(r.start, sizeof(struct adb_regs));
+ if (!adb) {
+ of_node_put(adbs);
+ return -ENOMEM;
+ }
+
+ 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);
+
+ irq = irq_of_parse_and_map(adbs, 0);
+ of_node_put(adbs);
+ if (request_irq(irq, macio_adb_interrupt, 0, "ADB", (void *)0)) {
+ printk(KERN_ERR "ADB: can't get irq %d\n", irq);
+ return -EAGAIN;
+ }
+ 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)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&macio_lock, flags);
+ out_8(&adb->active_hi.r, devs >> 8);
+ out_8(&adb->active_lo.r, devs);
+ out_8(&adb->autopoll.r, devs? APE: 0);
+ spin_unlock_irqrestore(&macio_lock, flags);
+ return 0;
+}
+
+static int macio_adb_reset_bus(void)
+{
+ unsigned long flags;
+ int timeout = 1000000;
+
+ /* Hrm... we may want to not lock interrupts for so
+ * long ... oh well, who uses that chip anyway ? :)
+ * That function will be seldom used during boot
+ * on rare machines, so...
+ */
+ spin_lock_irqsave(&macio_lock, flags);
+ 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);
+ spin_unlock_irqrestore(&macio_lock, flags);
+ return -1;
+ }
+ }
+ spin_unlock_irqrestore(&macio_lock, flags);
+ return 0;
+}
+
+/* Send an ADB command */
+static int macio_send_request(struct adb_request *req, int sync)
+{
+ unsigned long flags;
+ 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 = NULL;
+ req->sent = 0;
+ req->complete = 0;
+ req->reply_len = 0;
+
+ spin_lock_irqsave(&macio_lock, flags);
+ if (current_req) {
+ last_req->next = req;
+ last_req = req;
+ } else {
+ current_req = last_req = req;
+ out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
+ }
+ spin_unlock_irqrestore(&macio_lock, flags);
+
+ if (sync) {
+ while (!req->complete)
+ macio_adb_poll();
+ }
+
+ return 0;
+}
+
+static irqreturn_t macio_adb_interrupt(int irq, void *arg)
+{
+ int i, n, err;
+ struct adb_request *req = NULL;
+ unsigned char ibuf[16];
+ int ibuf_len = 0;
+ int complete = 0;
+ int autopoll = 0;
+ int handled = 0;
+
+ spin_lock(&macio_lock);
+ if (in_8(&adb->intr.r) & TAG) {
+ handled = 1;
+ req = current_req;
+ if (req) {
+ /* 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);
+ current_req = req->next;
+ complete = 1;
+ if (current_req)
+ out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
+ }
+ }
+ out_8(&adb->intr.r, 0);
+ }
+
+ if (in_8(&adb->intr.r) & DFB) {
+ handled = 1;
+ 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);
+ }
+ current_req = req->next;
+ complete = 1;
+ if (current_req)
+ out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
+ } else if (err == 0) {
+ /* autopoll data */
+ n = in_8(&adb->dcount.r) & HMB;
+ for (i = 0; i < n; ++i)
+ ibuf[i] = in_8(&adb->data[i].r);
+ ibuf_len = n;
+ autopoll = (in_8(&adb->dcount.r) & APD) != 0;
+ }
+ out_8(&adb->error.r, 0);
+ out_8(&adb->intr.r, 0);
+ }
+ spin_unlock(&macio_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)
+ adb_input(ibuf, ibuf_len, autopoll);
+
+ return IRQ_RETVAL(handled);
+}
+
+static void macio_adb_poll(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (in_8(&adb->intr.r) != 0)
+ macio_adb_interrupt(0, NULL);
+ local_irq_restore(flags);
+}