// SPDX-License-Identifier: GPL-2.0 /* * Driver for the ADB controller in the Mac I/O (Hydra) chip. */ #include <stdarg.h> #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 <asm/prom.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)); 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); }