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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * SCSI low-level driver for the 53c94 SCSI bus adaptor found4 * on Power Macintosh computers, controlling the external SCSI chain.5 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)6 * controller.7 *8 * Paul Mackerras, August 1996.9 * Copyright (C) 1996 Paul Mackerras.10 */11#include <linux/kernel.h>12#include <linux/delay.h>13#include <linux/types.h>14#include <linux/string.h>15#include <linux/slab.h>16#include <linux/blkdev.h>17#include <linux/proc_fs.h>18#include <linux/stat.h>19#include <linux/spinlock.h>20#include <linux/interrupt.h>21#include <linux/module.h>22#include <linux/pci.h>23#include <linux/pgtable.h>24#include <asm/dbdma.h>25#include <asm/io.h>26#include <asm/prom.h>27#include <asm/macio.h>28 29#include <scsi/scsi.h>30#include <scsi/scsi_cmnd.h>31#include <scsi/scsi_device.h>32#include <scsi/scsi_host.h>33 34#include "mac53c94.h"35 36enum fsc_phase {37 idle,38 selecting,39 dataing,40 completing,41 busfreeing,42};43 44struct fsc_state {45 struct mac53c94_regs __iomem *regs;46 int intr;47 struct dbdma_regs __iomem *dma;48 int dmaintr;49 int clk_freq;50 struct Scsi_Host *host;51 struct scsi_cmnd *request_q;52 struct scsi_cmnd *request_qtail;53 struct scsi_cmnd *current_req; /* req we're currently working on */54 enum fsc_phase phase; /* what we're currently trying to do */55 struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */56 void *dma_cmd_space;57 struct pci_dev *pdev;58 dma_addr_t dma_addr;59 struct macio_dev *mdev;60};61 62static void mac53c94_init(struct fsc_state *);63static void mac53c94_start(struct fsc_state *);64static void mac53c94_interrupt(int, void *);65static irqreturn_t do_mac53c94_interrupt(int, void *);66static void cmd_done(struct fsc_state *, int result);67static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);68 69static int mac53c94_queue_lck(struct scsi_cmnd *cmd)70{71 struct fsc_state *state;72 73#if 074 if (cmd->sc_data_direction == DMA_TO_DEVICE) {75 int i;76 printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);77 for (i = 0; i < cmd->cmd_len; ++i)78 printk(KERN_CONT " %.2x", cmd->cmnd[i]);79 printk(KERN_CONT "\n");80 printk(KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",81 scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd));82 }83#endif84 85 cmd->host_scribble = NULL;86 87 state = (struct fsc_state *) cmd->device->host->hostdata;88 89 if (state->request_q == NULL)90 state->request_q = cmd;91 else92 state->request_qtail->host_scribble = (void *) cmd;93 state->request_qtail = cmd;94 95 if (state->phase == idle)96 mac53c94_start(state);97 98 return 0;99}100 101static DEF_SCSI_QCMD(mac53c94_queue)102 103static int mac53c94_host_reset(struct scsi_cmnd *cmd)104{105 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;106 struct mac53c94_regs __iomem *regs = state->regs;107 struct dbdma_regs __iomem *dma = state->dma;108 unsigned long flags;109 110 spin_lock_irqsave(cmd->device->host->host_lock, flags);111 112 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);113 writeb(CMD_SCSI_RESET, ®s->command); /* assert RST */114 udelay(100); /* leave it on for a while (>= 25us) */115 writeb(CMD_RESET, ®s->command);116 udelay(20);117 mac53c94_init(state);118 writeb(CMD_NOP, ®s->command);119 120 spin_unlock_irqrestore(cmd->device->host->host_lock, flags);121 return SUCCESS;122}123 124static void mac53c94_init(struct fsc_state *state)125{126 struct mac53c94_regs __iomem *regs = state->regs;127 struct dbdma_regs __iomem *dma = state->dma;128 129 writeb(state->host->this_id | CF1_PAR_ENABLE, ®s->config1);130 writeb(TIMO_VAL(250), ®s->sel_timeout); /* 250ms */131 writeb(CLKF_VAL(state->clk_freq), ®s->clk_factor);132 writeb(CF2_FEATURE_EN, ®s->config2);133 writeb(0, ®s->config3);134 writeb(0, ®s->sync_period);135 writeb(0, ®s->sync_offset);136 (void)readb(®s->interrupt);137 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);138}139 140/*141 * Start the next command for a 53C94.142 * Should be called with interrupts disabled.143 */144static void mac53c94_start(struct fsc_state *state)145{146 struct scsi_cmnd *cmd;147 struct mac53c94_regs __iomem *regs = state->regs;148 int i;149 150 if (state->phase != idle || state->current_req != NULL)151 panic("inappropriate mac53c94_start (state=%p)", state);152 if (state->request_q == NULL)153 return;154 state->current_req = cmd = state->request_q;155 state->request_q = (struct scsi_cmnd *) cmd->host_scribble;156 157 /* Off we go */158 writeb(0, ®s->count_lo);159 writeb(0, ®s->count_mid);160 writeb(0, ®s->count_hi);161 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command);162 udelay(1);163 writeb(CMD_FLUSH, ®s->command);164 udelay(1);165 writeb(cmd->device->id, ®s->dest_id);166 writeb(0, ®s->sync_period);167 writeb(0, ®s->sync_offset);168 169 /* load the command into the FIFO */170 for (i = 0; i < cmd->cmd_len; ++i)171 writeb(cmd->cmnd[i], ®s->fifo);172 173 /* do select without ATN XXX */174 writeb(CMD_SELECT, ®s->command);175 state->phase = selecting;176 177 set_dma_cmds(state, cmd);178}179 180static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)181{182 unsigned long flags;183 struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;184 185 spin_lock_irqsave(dev->host_lock, flags);186 mac53c94_interrupt(irq, dev_id);187 spin_unlock_irqrestore(dev->host_lock, flags);188 return IRQ_HANDLED;189}190 191static void mac53c94_interrupt(int irq, void *dev_id)192{193 struct fsc_state *state = (struct fsc_state *) dev_id;194 struct mac53c94_regs __iomem *regs = state->regs;195 struct dbdma_regs __iomem *dma = state->dma;196 struct scsi_cmnd *const cmd = state->current_req;197 struct mac53c94_cmd_priv *const mcmd = mac53c94_priv(cmd);198 int nb, stat, seq, intr;199 static int mac53c94_errors;200 201 /*202 * Apparently, reading the interrupt register unlatches203 * the status and sequence step registers.204 */205 seq = readb(®s->seqstep);206 stat = readb(®s->status);207 intr = readb(®s->interrupt);208 209#if 0210 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",211 intr, stat, seq, state->phase);212#endif213 214 if (intr & INTR_RESET) {215 /* SCSI bus was reset */216 printk(KERN_INFO "external SCSI bus reset detected\n");217 writeb(CMD_NOP, ®s->command);218 writel(RUN << 16, &dma->control); /* stop dma */219 cmd_done(state, DID_RESET << 16);220 return;221 }222 if (intr & INTR_ILL_CMD) {223 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",224 intr, stat, seq, state->phase);225 cmd_done(state, DID_ERROR << 16);226 return;227 }228 if (stat & STAT_ERROR) {229#if 0230 /* XXX these seem to be harmless? */231 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",232 intr, stat, seq, state->phase);233#endif234 ++mac53c94_errors;235 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command);236 }237 if (!cmd) {238 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");239 return;240 }241 if (stat & STAT_PARITY) {242 printk(KERN_ERR "mac53c94: parity error\n");243 cmd_done(state, DID_PARITY << 16);244 return;245 }246 switch (state->phase) {247 case selecting:248 if (intr & INTR_DISCONNECT) {249 /* selection timed out */250 cmd_done(state, DID_BAD_TARGET << 16);251 return;252 }253 if (intr != INTR_BUS_SERV + INTR_DONE) {254 printk(KERN_DEBUG "got intr %x during selection\n", intr);255 cmd_done(state, DID_ERROR << 16);256 return;257 }258 if ((seq & SS_MASK) != SS_DONE) {259 printk(KERN_DEBUG "seq step %x after command\n", seq);260 cmd_done(state, DID_ERROR << 16);261 return;262 }263 writeb(CMD_NOP, ®s->command);264 /* set DMA controller going if any data to transfer */265 if ((stat & (STAT_MSG|STAT_CD)) == 0266 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {267 nb = mcmd->this_residual;268 if (nb > 0xfff0)269 nb = 0xfff0;270 mcmd->this_residual -= nb;271 writeb(nb, ®s->count_lo);272 writeb(nb >> 8, ®s->count_mid);273 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command);274 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);275 writel((RUN << 16) | RUN, &dma->control);276 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command);277 state->phase = dataing;278 break;279 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {280 /* up to status phase already */281 writeb(CMD_I_COMPLETE, ®s->command);282 state->phase = completing;283 } else {284 printk(KERN_DEBUG "in unexpected phase %x after cmd\n",285 stat & STAT_PHASE);286 cmd_done(state, DID_ERROR << 16);287 return;288 }289 break;290 291 case dataing:292 if (intr != INTR_BUS_SERV) {293 printk(KERN_DEBUG "got intr %x before status\n", intr);294 cmd_done(state, DID_ERROR << 16);295 return;296 }297 if (mcmd->this_residual != 0298 && (stat & (STAT_MSG|STAT_CD)) == 0) {299 /* Set up the count regs to transfer more */300 nb = mcmd->this_residual;301 if (nb > 0xfff0)302 nb = 0xfff0;303 mcmd->this_residual -= nb;304 writeb(nb, ®s->count_lo);305 writeb(nb >> 8, ®s->count_mid);306 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command);307 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command);308 break;309 }310 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {311 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);312 }313 writel(RUN << 16, &dma->control); /* stop dma */314 scsi_dma_unmap(cmd);315 /* should check dma status */316 writeb(CMD_I_COMPLETE, ®s->command);317 state->phase = completing;318 break;319 case completing:320 if (intr != INTR_DONE) {321 printk(KERN_DEBUG "got intr %x on completion\n", intr);322 cmd_done(state, DID_ERROR << 16);323 return;324 }325 mcmd->status = readb(®s->fifo);326 mcmd->message = readb(®s->fifo);327 writeb(CMD_ACCEPT_MSG, ®s->command);328 state->phase = busfreeing;329 break;330 case busfreeing:331 if (intr != INTR_DISCONNECT) {332 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);333 }334 cmd_done(state, (DID_OK << 16) + (mcmd->message << 8) + mcmd->status);335 break;336 default:337 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);338 }339}340 341static void cmd_done(struct fsc_state *state, int result)342{343 struct scsi_cmnd *cmd;344 345 cmd = state->current_req;346 if (cmd) {347 cmd->result = result;348 scsi_done(cmd);349 state->current_req = NULL;350 }351 state->phase = idle;352 mac53c94_start(state);353}354 355/*356 * Set up DMA commands for transferring data.357 */358static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)359{360 int i, dma_cmd, total, nseg;361 struct scatterlist *scl;362 struct dbdma_cmd *dcmds;363 dma_addr_t dma_addr;364 u32 dma_len;365 366 nseg = scsi_dma_map(cmd);367 BUG_ON(nseg < 0);368 if (!nseg)369 return;370 371 dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?372 OUTPUT_MORE : INPUT_MORE;373 dcmds = state->dma_cmds;374 total = 0;375 376 scsi_for_each_sg(cmd, scl, nseg, i) {377 dma_addr = sg_dma_address(scl);378 dma_len = sg_dma_len(scl);379 if (dma_len > 0xffff)380 panic("mac53c94: scatterlist element >= 64k");381 total += dma_len;382 dcmds->req_count = cpu_to_le16(dma_len);383 dcmds->command = cpu_to_le16(dma_cmd);384 dcmds->phy_addr = cpu_to_le32(dma_addr);385 dcmds->xfer_status = 0;386 ++dcmds;387 }388 389 dma_cmd += OUTPUT_LAST - OUTPUT_MORE;390 dcmds[-1].command = cpu_to_le16(dma_cmd);391 dcmds->command = cpu_to_le16(DBDMA_STOP);392 mac53c94_priv(cmd)->this_residual = total;393}394 395static const struct scsi_host_template mac53c94_template = {396 .proc_name = "53c94",397 .name = "53C94",398 .queuecommand = mac53c94_queue,399 .eh_host_reset_handler = mac53c94_host_reset,400 .can_queue = 1,401 .this_id = 7,402 .sg_tablesize = SG_ALL,403 .max_segment_size = 65535,404 .cmd_size = sizeof(struct mac53c94_cmd_priv),405};406 407static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)408{409 struct device_node *node = macio_get_of_node(mdev);410 struct pci_dev *pdev = macio_get_pci_dev(mdev);411 struct fsc_state *state;412 struct Scsi_Host *host;413 void *dma_cmd_space;414 const unsigned char *clkprop;415 int proplen, rc = -ENODEV;416 417 if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {418 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"419 " (got %d/%d)\n",420 macio_resource_count(mdev), macio_irq_count(mdev));421 return -ENODEV;422 }423 424 if (macio_request_resources(mdev, "mac53c94") != 0) {425 printk(KERN_ERR "mac53c94: unable to request memory resources");426 return -EBUSY;427 }428 429 host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));430 if (host == NULL) {431 printk(KERN_ERR "mac53c94: couldn't register host");432 rc = -ENOMEM;433 goto out_release;434 }435 436 state = (struct fsc_state *) host->hostdata;437 macio_set_drvdata(mdev, state);438 state->host = host;439 state->pdev = pdev;440 state->mdev = mdev;441 442 state->regs = (struct mac53c94_regs __iomem *)443 ioremap(macio_resource_start(mdev, 0), 0x1000);444 state->intr = macio_irq(mdev, 0);445 state->dma = (struct dbdma_regs __iomem *)446 ioremap(macio_resource_start(mdev, 1), 0x1000);447 state->dmaintr = macio_irq(mdev, 1);448 if (state->regs == NULL || state->dma == NULL) {449 printk(KERN_ERR "mac53c94: ioremap failed for %pOF\n", node);450 goto out_free;451 }452 453 clkprop = of_get_property(node, "clock-frequency", &proplen);454 if (clkprop == NULL || proplen != sizeof(int)) {455 printk(KERN_ERR "%pOF: can't get clock frequency, "456 "assuming 25MHz\n", node);457 state->clk_freq = 25000000;458 } else459 state->clk_freq = *(int *)clkprop;460 461 /* Space for dma command list: +1 for stop command,462 * +1 to allow for aligning.463 * XXX FIXME: Use DMA consistent routines464 */465 dma_cmd_space = kmalloc_array(host->sg_tablesize + 2,466 sizeof(struct dbdma_cmd),467 GFP_KERNEL);468 if (!dma_cmd_space) {469 printk(KERN_ERR "mac53c94: couldn't allocate dma "470 "command space for %pOF\n", node);471 rc = -ENOMEM;472 goto out_free;473 }474 475 state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);476 memset(state->dma_cmds, 0, (host->sg_tablesize + 1)477 * sizeof(struct dbdma_cmd));478 state->dma_cmd_space = dma_cmd_space;479 480 mac53c94_init(state);481 482 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {483 printk(KERN_ERR "mac53C94: can't get irq %d for %pOF\n",484 state->intr, node);485 goto out_free_dma;486 }487 488 rc = scsi_add_host(host, &mdev->ofdev.dev);489 if (rc != 0)490 goto out_release_irq;491 492 scsi_scan_host(host);493 return 0;494 495 out_release_irq:496 free_irq(state->intr, state);497 out_free_dma:498 kfree(state->dma_cmd_space);499 out_free:500 if (state->dma != NULL)501 iounmap(state->dma);502 if (state->regs != NULL)503 iounmap(state->regs);504 scsi_host_put(host);505 out_release:506 macio_release_resources(mdev);507 508 return rc;509}510 511static void mac53c94_remove(struct macio_dev *mdev)512{513 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);514 struct Scsi_Host *host = fp->host;515 516 scsi_remove_host(host);517 518 free_irq(fp->intr, fp);519 520 if (fp->regs)521 iounmap(fp->regs);522 if (fp->dma)523 iounmap(fp->dma);524 kfree(fp->dma_cmd_space);525 526 scsi_host_put(host);527 528 macio_release_resources(mdev);529}530 531static struct of_device_id mac53c94_match[] = 532{533 {534 .name = "53c94",535 },536 {},537};538MODULE_DEVICE_TABLE (of, mac53c94_match);539 540static struct macio_driver mac53c94_driver = 541{542 .driver = {543 .name = "mac53c94",544 .owner = THIS_MODULE,545 .of_match_table = mac53c94_match,546 },547 .probe = mac53c94_probe,548 .remove = mac53c94_remove,549};550 551 552static int __init init_mac53c94(void)553{554 return macio_register_driver(&mac53c94_driver);555}556 557static void __exit exit_mac53c94(void)558{559 return macio_unregister_driver(&mac53c94_driver);560}561 562module_init(init_mac53c94);563module_exit(exit_mac53c94);564 565MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");566MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");567MODULE_LICENSE("GPL");568