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1// SPDX-License-Identifier: GPL-2.02/*3 * Driver for the ADB controller in the Mac I/O (Hydra) chip.4 */5#include <linux/types.h>6#include <linux/errno.h>7#include <linux/kernel.h>8#include <linux/delay.h>9#include <linux/spinlock.h>10#include <linux/interrupt.h>11#include <linux/pgtable.h>12#include <linux/of.h>13#include <linux/of_address.h>14#include <linux/of_irq.h>15#include <linux/adb.h>16 17#include <asm/io.h>18#include <asm/hydra.h>19#include <asm/irq.h>20#include <linux/init.h>21#include <linux/ioport.h>22 23struct preg {24 unsigned char r;25 char pad[15];26};27 28struct adb_regs {29 struct preg intr;30 struct preg data[9];31 struct preg intr_enb;32 struct preg dcount;33 struct preg error;34 struct preg ctrl;35 struct preg autopoll;36 struct preg active_hi;37 struct preg active_lo;38 struct preg test;39};40 41/* Bits in intr and intr_enb registers */42#define DFB 1 /* data from bus */43#define TAG 2 /* transfer access grant */44 45/* Bits in dcount register */46#define HMB 0x0f /* how many bytes */47#define APD 0x10 /* auto-poll data */48 49/* Bits in error register */50#define NRE 1 /* no response error */51#define DLE 2 /* data lost error */52 53/* Bits in ctrl register */54#define TAR 1 /* transfer access request */55#define DTB 2 /* data to bus */56#define CRE 4 /* command response expected */57#define ADB_RST 8 /* ADB reset */58 59/* Bits in autopoll register */60#define APE 1 /* autopoll enable */61 62static volatile struct adb_regs __iomem *adb;63static struct adb_request *current_req, *last_req;64static DEFINE_SPINLOCK(macio_lock);65 66static int macio_probe(void);67static int macio_init(void);68static irqreturn_t macio_adb_interrupt(int irq, void *arg);69static int macio_send_request(struct adb_request *req, int sync);70static int macio_adb_autopoll(int devs);71static void macio_adb_poll(void);72static int macio_adb_reset_bus(void);73 74struct adb_driver macio_adb_driver = {75 .name = "MACIO",76 .probe = macio_probe,77 .init = macio_init,78 .send_request = macio_send_request,79 .autopoll = macio_adb_autopoll,80 .poll = macio_adb_poll,81 .reset_bus = macio_adb_reset_bus,82};83 84int macio_probe(void)85{86 struct device_node *np __free(device_node) =87 of_find_compatible_node(NULL, "adb", "chrp,adb0");88 89 if (np)90 return 0;91 92 return -ENODEV;93}94 95int macio_init(void)96{97 struct device_node *adbs __free(device_node) =98 of_find_compatible_node(NULL, "adb", "chrp,adb0");99 struct resource r;100 unsigned int irq;101 102 if (!adbs)103 return -ENXIO;104 105 if (of_address_to_resource(adbs, 0, &r))106 return -ENXIO;107 108 adb = ioremap(r.start, sizeof(struct adb_regs));109 if (!adb)110 return -ENOMEM;111 112 113 out_8(&adb->ctrl.r, 0);114 out_8(&adb->intr.r, 0);115 out_8(&adb->error.r, 0);116 out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */117 out_8(&adb->active_lo.r, 0xff);118 out_8(&adb->autopoll.r, APE);119 120 irq = irq_of_parse_and_map(adbs, 0);121 if (request_irq(irq, macio_adb_interrupt, 0, "ADB", (void *)0)) {122 iounmap(adb);123 printk(KERN_ERR "ADB: can't get irq %d\n", irq);124 return -EAGAIN;125 }126 out_8(&adb->intr_enb.r, DFB | TAG);127 128 printk("adb: mac-io driver 1.0 for unified ADB\n");129 130 return 0;131}132 133static int macio_adb_autopoll(int devs)134{135 unsigned long flags;136 137 spin_lock_irqsave(&macio_lock, flags);138 out_8(&adb->active_hi.r, devs >> 8);139 out_8(&adb->active_lo.r, devs);140 out_8(&adb->autopoll.r, devs? APE: 0);141 spin_unlock_irqrestore(&macio_lock, flags);142 return 0;143}144 145static int macio_adb_reset_bus(void)146{147 unsigned long flags;148 int timeout = 1000000;149 150 /* Hrm... we may want to not lock interrupts for so151 * long ... oh well, who uses that chip anyway ? :)152 * That function will be seldom used during boot153 * on rare machines, so...154 */155 spin_lock_irqsave(&macio_lock, flags);156 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST);157 while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {158 if (--timeout == 0) {159 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);160 spin_unlock_irqrestore(&macio_lock, flags);161 return -1;162 }163 }164 spin_unlock_irqrestore(&macio_lock, flags);165 return 0;166}167 168/* Send an ADB command */169static int macio_send_request(struct adb_request *req, int sync)170{171 unsigned long flags;172 int i;173 174 if (req->data[0] != ADB_PACKET)175 return -EINVAL;176 177 for (i = 0; i < req->nbytes - 1; ++i)178 req->data[i] = req->data[i+1];179 --req->nbytes;180 181 req->next = NULL;182 req->sent = 0;183 req->complete = 0;184 req->reply_len = 0;185 186 spin_lock_irqsave(&macio_lock, flags);187 if (current_req) {188 last_req->next = req;189 last_req = req;190 } else {191 current_req = last_req = req;192 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);193 }194 spin_unlock_irqrestore(&macio_lock, flags);195 196 if (sync) {197 while (!req->complete)198 macio_adb_poll();199 }200 201 return 0;202}203 204static irqreturn_t macio_adb_interrupt(int irq, void *arg)205{206 int i, n, err;207 struct adb_request *req = NULL;208 unsigned char ibuf[16];209 int ibuf_len = 0;210 int complete = 0;211 int autopoll = 0;212 int handled = 0;213 214 spin_lock(&macio_lock);215 if (in_8(&adb->intr.r) & TAG) {216 handled = 1;217 req = current_req;218 if (req) {219 /* put the current request in */220 for (i = 0; i < req->nbytes; ++i)221 out_8(&adb->data[i].r, req->data[i]);222 out_8(&adb->dcount.r, req->nbytes & HMB);223 req->sent = 1;224 if (req->reply_expected) {225 out_8(&adb->ctrl.r, DTB + CRE);226 } else {227 out_8(&adb->ctrl.r, DTB);228 current_req = req->next;229 complete = 1;230 if (current_req)231 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);232 }233 }234 out_8(&adb->intr.r, 0);235 }236 237 if (in_8(&adb->intr.r) & DFB) {238 handled = 1;239 err = in_8(&adb->error.r);240 if (current_req && current_req->sent) {241 /* this is the response to a command */242 req = current_req;243 if (err == 0) {244 req->reply_len = in_8(&adb->dcount.r) & HMB;245 for (i = 0; i < req->reply_len; ++i)246 req->reply[i] = in_8(&adb->data[i].r);247 }248 current_req = req->next;249 complete = 1;250 if (current_req)251 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);252 } else if (err == 0) {253 /* autopoll data */254 n = in_8(&adb->dcount.r) & HMB;255 for (i = 0; i < n; ++i)256 ibuf[i] = in_8(&adb->data[i].r);257 ibuf_len = n;258 autopoll = (in_8(&adb->dcount.r) & APD) != 0;259 }260 out_8(&adb->error.r, 0);261 out_8(&adb->intr.r, 0);262 }263 spin_unlock(&macio_lock);264 if (complete && req) {265 void (*done)(struct adb_request *) = req->done;266 mb();267 req->complete = 1;268 /* Here, we assume that if the request has a done member, the269 * struct request will survive to setting req->complete to 1270 */271 if (done)272 (*done)(req);273 }274 if (ibuf_len)275 adb_input(ibuf, ibuf_len, autopoll);276 277 return IRQ_RETVAL(handled);278}279 280static void macio_adb_poll(void)281{282 unsigned long flags;283 284 local_irq_save(flags);285 if (in_8(&adb->intr.r) != 0)286 macio_adb_interrupt(0, NULL);287 local_irq_restore(flags);288}289