2 * SCSI low-level driver for the 53c94 SCSI bus adaptor found
3 * on Power Macintosh computers, controlling the external SCSI chain.
4 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
7 * Paul Mackerras, August 1996.
8 * Copyright (C) 1996 Paul Mackerras.
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/slab.h>
15 #include <linux/blkdev.h>
16 #include <linux/proc_fs.h>
17 #include <linux/stat.h>
18 #include <linux/spinlock.h>
19 #include <linux/interrupt.h>
20 #include <asm/dbdma.h>
22 #include <asm/pgtable.h>
24 #include <asm/system.h>
25 #include <asm/pci-bridge.h>
26 #include <asm/macio.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_host.h>
44 struct mac53c94_regs __iomem *regs;
46 struct dbdma_regs __iomem *dma;
49 struct Scsi_Host *host;
50 struct scsi_cmnd *request_q;
51 struct scsi_cmnd *request_qtail;
52 struct scsi_cmnd *current_req; /* req we're currently working on */
53 enum fsc_phase phase; /* what we're currently trying to do */
54 struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */
58 struct macio_dev *mdev;
61 static void mac53c94_init(struct fsc_state *);
62 static void mac53c94_start(struct fsc_state *);
63 static void mac53c94_interrupt(int, void *);
64 static irqreturn_t do_mac53c94_interrupt(int, void *);
65 static void cmd_done(struct fsc_state *, int result);
66 static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
69 static int mac53c94_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
71 struct fsc_state *state;
74 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
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));
85 cmd->scsi_done = done;
86 cmd->host_scribble = NULL;
88 state = (struct fsc_state *) cmd->device->host->hostdata;
90 if (state->request_q == NULL)
91 state->request_q = cmd;
93 state->request_qtail->host_scribble = (void *) cmd;
94 state->request_qtail = cmd;
96 if (state->phase == idle)
97 mac53c94_start(state);
102 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
104 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
105 struct mac53c94_regs __iomem *regs = state->regs;
106 struct dbdma_regs __iomem *dma = state->dma;
109 spin_lock_irqsave(cmd->device->host->host_lock, flags);
111 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
112 writeb(CMD_SCSI_RESET, ®s->command); /* assert RST */
113 udelay(100); /* leave it on for a while (>= 25us) */
114 writeb(CMD_RESET, ®s->command);
116 mac53c94_init(state);
117 writeb(CMD_NOP, ®s->command);
119 spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
123 static void mac53c94_init(struct fsc_state *state)
125 struct mac53c94_regs __iomem *regs = state->regs;
126 struct dbdma_regs __iomem *dma = state->dma;
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 x = readb(®s->interrupt);
137 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
141 * Start the next command for a 53C94.
142 * Should be called with interrupts disabled.
144 static void mac53c94_start(struct fsc_state *state)
146 struct scsi_cmnd *cmd;
147 struct mac53c94_regs __iomem *regs = state->regs;
150 if (state->phase != idle || state->current_req != NULL)
151 panic("inappropriate mac53c94_start (state=%p)", state);
152 if (state->request_q == NULL)
154 state->current_req = cmd = state->request_q;
155 state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
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);
163 writeb(CMD_FLUSH, ®s->command);
165 writeb(cmd->device->id, ®s->dest_id);
166 writeb(0, ®s->sync_period);
167 writeb(0, ®s->sync_offset);
169 /* load the command into the FIFO */
170 for (i = 0; i < cmd->cmd_len; ++i)
171 writeb(cmd->cmnd[i], ®s->fifo);
173 /* do select without ATN XXX */
174 writeb(CMD_SELECT, ®s->command);
175 state->phase = selecting;
177 set_dma_cmds(state, cmd);
180 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
183 struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
185 spin_lock_irqsave(dev->host_lock, flags);
186 mac53c94_interrupt(irq, dev_id);
187 spin_unlock_irqrestore(dev->host_lock, flags);
191 static void mac53c94_interrupt(int irq, void *dev_id)
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 *cmd = state->current_req;
197 int nb, stat, seq, intr;
198 static int mac53c94_errors;
201 * Apparently, reading the interrupt register unlatches
202 * the status and sequence step registers.
204 seq = readb(®s->seqstep);
205 stat = readb(®s->status);
206 intr = readb(®s->interrupt);
209 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
210 intr, stat, seq, state->phase);
213 if (intr & INTR_RESET) {
214 /* SCSI bus was reset */
215 printk(KERN_INFO "external SCSI bus reset detected\n");
216 writeb(CMD_NOP, ®s->command);
217 writel(RUN << 16, &dma->control); /* stop dma */
218 cmd_done(state, DID_RESET << 16);
221 if (intr & INTR_ILL_CMD) {
222 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
223 intr, stat, seq, state->phase);
224 cmd_done(state, DID_ERROR << 16);
227 if (stat & STAT_ERROR) {
229 /* XXX these seem to be harmless? */
230 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
231 intr, stat, seq, state->phase);
234 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command);
237 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
240 if (stat & STAT_PARITY) {
241 printk(KERN_ERR "mac53c94: parity error\n");
242 cmd_done(state, DID_PARITY << 16);
245 switch (state->phase) {
247 if (intr & INTR_DISCONNECT) {
248 /* selection timed out */
249 cmd_done(state, DID_BAD_TARGET << 16);
252 if (intr != INTR_BUS_SERV + INTR_DONE) {
253 printk(KERN_DEBUG "got intr %x during selection\n", intr);
254 cmd_done(state, DID_ERROR << 16);
257 if ((seq & SS_MASK) != SS_DONE) {
258 printk(KERN_DEBUG "seq step %x after command\n", seq);
259 cmd_done(state, DID_ERROR << 16);
262 writeb(CMD_NOP, ®s->command);
263 /* set DMA controller going if any data to transfer */
264 if ((stat & (STAT_MSG|STAT_CD)) == 0
265 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
266 nb = cmd->SCp.this_residual;
269 cmd->SCp.this_residual -= nb;
270 writeb(nb, ®s->count_lo);
271 writeb(nb >> 8, ®s->count_mid);
272 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command);
273 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
274 writel((RUN << 16) | RUN, &dma->control);
275 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command);
276 state->phase = dataing;
278 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
279 /* up to status phase already */
280 writeb(CMD_I_COMPLETE, ®s->command);
281 state->phase = completing;
283 printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
285 cmd_done(state, DID_ERROR << 16);
291 if (intr != INTR_BUS_SERV) {
292 printk(KERN_DEBUG "got intr %x before status\n", intr);
293 cmd_done(state, DID_ERROR << 16);
296 if (cmd->SCp.this_residual != 0
297 && (stat & (STAT_MSG|STAT_CD)) == 0) {
298 /* Set up the count regs to transfer more */
299 nb = cmd->SCp.this_residual;
302 cmd->SCp.this_residual -= nb;
303 writeb(nb, ®s->count_lo);
304 writeb(nb >> 8, ®s->count_mid);
305 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command);
306 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command);
309 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
310 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
312 writel(RUN << 16, &dma->control); /* stop dma */
314 /* should check dma status */
315 writeb(CMD_I_COMPLETE, ®s->command);
316 state->phase = completing;
319 if (intr != INTR_DONE) {
320 printk(KERN_DEBUG "got intr %x on completion\n", intr);
321 cmd_done(state, DID_ERROR << 16);
324 cmd->SCp.Status = readb(®s->fifo);
325 cmd->SCp.Message = readb(®s->fifo);
326 cmd->result = CMD_ACCEPT_MSG;
327 writeb(CMD_ACCEPT_MSG, ®s->command);
328 state->phase = busfreeing;
331 if (intr != INTR_DISCONNECT) {
332 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
334 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
338 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
342 static void cmd_done(struct fsc_state *state, int result)
344 struct scsi_cmnd *cmd;
346 cmd = state->current_req;
348 cmd->result = result;
349 (*cmd->scsi_done)(cmd);
350 state->current_req = NULL;
353 mac53c94_start(state);
357 * Set up DMA commands for transferring data.
359 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
361 int i, dma_cmd, total, nseg;
362 struct scatterlist *scl;
363 struct dbdma_cmd *dcmds;
367 nseg = scsi_dma_map(cmd);
372 dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
373 OUTPUT_MORE : INPUT_MORE;
374 dcmds = state->dma_cmds;
377 scsi_for_each_sg(cmd, scl, nseg, i) {
378 dma_addr = sg_dma_address(scl);
379 dma_len = sg_dma_len(scl);
380 if (dma_len > 0xffff)
381 panic("mac53c94: scatterlist element >= 64k");
383 st_le16(&dcmds->req_count, dma_len);
384 st_le16(&dcmds->command, dma_cmd);
385 st_le32(&dcmds->phy_addr, dma_addr);
386 dcmds->xfer_status = 0;
390 dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
391 st_le16(&dcmds[-1].command, dma_cmd);
392 st_le16(&dcmds->command, DBDMA_STOP);
393 cmd->SCp.this_residual = total;
396 static struct scsi_host_template mac53c94_template = {
397 .proc_name = "53c94",
399 .queuecommand = mac53c94_queue,
400 .eh_host_reset_handler = mac53c94_host_reset,
403 .sg_tablesize = SG_ALL,
405 .use_clustering = DISABLE_CLUSTERING,
408 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
410 struct device_node *node = macio_get_of_node(mdev);
411 struct pci_dev *pdev = macio_get_pci_dev(mdev);
412 struct fsc_state *state;
413 struct Scsi_Host *host;
415 const unsigned char *clkprop;
416 int proplen, rc = -ENODEV;
418 if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
419 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
421 macio_resource_count(mdev), macio_irq_count(mdev));
425 if (macio_request_resources(mdev, "mac53c94") != 0) {
426 printk(KERN_ERR "mac53c94: unable to request memory resources");
430 host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
432 printk(KERN_ERR "mac53c94: couldn't register host");
437 state = (struct fsc_state *) host->hostdata;
438 macio_set_drvdata(mdev, state);
443 state->regs = (struct mac53c94_regs __iomem *)
444 ioremap(macio_resource_start(mdev, 0), 0x1000);
445 state->intr = macio_irq(mdev, 0);
446 state->dma = (struct dbdma_regs __iomem *)
447 ioremap(macio_resource_start(mdev, 1), 0x1000);
448 state->dmaintr = macio_irq(mdev, 1);
449 if (state->regs == NULL || state->dma == NULL) {
450 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
455 clkprop = of_get_property(node, "clock-frequency", &proplen);
456 if (clkprop == NULL || proplen != sizeof(int)) {
457 printk(KERN_ERR "%s: can't get clock frequency, "
458 "assuming 25MHz\n", node->full_name);
459 state->clk_freq = 25000000;
461 state->clk_freq = *(int *)clkprop;
463 /* Space for dma command list: +1 for stop command,
464 * +1 to allow for aligning.
465 * XXX FIXME: Use DMA consistent routines
467 dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
468 sizeof(struct dbdma_cmd), GFP_KERNEL);
469 if (dma_cmd_space == 0) {
470 printk(KERN_ERR "mac53c94: couldn't allocate dma "
471 "command space for %s\n", node->full_name);
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;
480 mac53c94_init(state);
482 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
483 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
484 state->intr, node->full_name);
488 rc = scsi_add_host(host, &mdev->ofdev.dev);
490 goto out_release_irq;
492 scsi_scan_host(host);
496 free_irq(state->intr, state);
498 kfree(state->dma_cmd_space);
500 if (state->dma != NULL)
502 if (state->regs != NULL)
503 iounmap(state->regs);
506 macio_release_resources(mdev);
511 static int mac53c94_remove(struct macio_dev *mdev)
513 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
514 struct Scsi_Host *host = fp->host;
516 scsi_remove_host(host);
518 free_irq(fp->intr, fp);
524 kfree(fp->dma_cmd_space);
528 macio_release_resources(mdev);
534 static struct of_device_id mac53c94_match[] =
541 MODULE_DEVICE_TABLE (of, mac53c94_match);
543 static struct macio_driver mac53c94_driver =
546 .match_table = mac53c94_match,
547 .probe = mac53c94_probe,
548 .remove = mac53c94_remove,
552 static int __init init_mac53c94(void)
554 return macio_register_driver(&mac53c94_driver);
557 static void __exit exit_mac53c94(void)
559 return macio_unregister_driver(&mac53c94_driver);
562 module_init(init_mac53c94);
563 module_exit(exit_mac53c94);
565 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
566 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
567 MODULE_LICENSE("GPL");