diff options
Diffstat (limited to 'drivers/macintosh/macio-adb.c')
| -rw-r--r-- | drivers/macintosh/macio-adb.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/macintosh/macio-adb.c b/drivers/macintosh/macio-adb.c new file mode 100644 index 000000000..cd4e34d15 --- /dev/null +++ b/drivers/macintosh/macio-adb.c @@ -0,0 +1,290 @@ +// 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 == 0) + 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 != 0) { + 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; + if ((req = current_req) != 0) { + /* 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); +} |