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 <linux/module.h>
21 #include <linux/pci.h>
22 #include <asm/dbdma.h>
24 #include <asm/pgtable.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_lck(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 DEF_SCSI_QCMD(mac53c94_queue)
104 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
106 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
107 struct mac53c94_regs __iomem *regs = state->regs;
108 struct dbdma_regs __iomem *dma = state->dma;
111 spin_lock_irqsave(cmd->device->host->host_lock, flags);
113 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
114 writeb(CMD_SCSI_RESET, ®s->command); /* assert RST */
115 udelay(100); /* leave it on for a while (>= 25us) */
116 writeb(CMD_RESET, ®s->command);
118 mac53c94_init(state);
119 writeb(CMD_NOP, ®s->command);
121 spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
125 static void mac53c94_init(struct fsc_state *state)
127 struct mac53c94_regs __iomem *regs = state->regs;
128 struct dbdma_regs __iomem *dma = state->dma;
131 writeb(state->host->this_id | CF1_PAR_ENABLE, ®s->config1);
132 writeb(TIMO_VAL(250), ®s->sel_timeout); /* 250ms */
133 writeb(CLKF_VAL(state->clk_freq), ®s->clk_factor);
134 writeb(CF2_FEATURE_EN, ®s->config2);
135 writeb(0, ®s->config3);
136 writeb(0, ®s->sync_period);
137 writeb(0, ®s->sync_offset);
138 x = readb(®s->interrupt);
139 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
143 * Start the next command for a 53C94.
144 * Should be called with interrupts disabled.
146 static void mac53c94_start(struct fsc_state *state)
148 struct scsi_cmnd *cmd;
149 struct mac53c94_regs __iomem *regs = state->regs;
152 if (state->phase != idle || state->current_req != NULL)
153 panic("inappropriate mac53c94_start (state=%p)", state);
154 if (state->request_q == NULL)
156 state->current_req = cmd = state->request_q;
157 state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
160 writeb(0, ®s->count_lo);
161 writeb(0, ®s->count_mid);
162 writeb(0, ®s->count_hi);
163 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command);
165 writeb(CMD_FLUSH, ®s->command);
167 writeb(cmd->device->id, ®s->dest_id);
168 writeb(0, ®s->sync_period);
169 writeb(0, ®s->sync_offset);
171 /* load the command into the FIFO */
172 for (i = 0; i < cmd->cmd_len; ++i)
173 writeb(cmd->cmnd[i], ®s->fifo);
175 /* do select without ATN XXX */
176 writeb(CMD_SELECT, ®s->command);
177 state->phase = selecting;
179 set_dma_cmds(state, cmd);
182 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
185 struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
187 spin_lock_irqsave(dev->host_lock, flags);
188 mac53c94_interrupt(irq, dev_id);
189 spin_unlock_irqrestore(dev->host_lock, flags);
193 static void mac53c94_interrupt(int irq, void *dev_id)
195 struct fsc_state *state = (struct fsc_state *) dev_id;
196 struct mac53c94_regs __iomem *regs = state->regs;
197 struct dbdma_regs __iomem *dma = state->dma;
198 struct scsi_cmnd *cmd = state->current_req;
199 int nb, stat, seq, intr;
200 static int mac53c94_errors;
203 * Apparently, reading the interrupt register unlatches
204 * the status and sequence step registers.
206 seq = readb(®s->seqstep);
207 stat = readb(®s->status);
208 intr = readb(®s->interrupt);
211 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
212 intr, stat, seq, state->phase);
215 if (intr & INTR_RESET) {
216 /* SCSI bus was reset */
217 printk(KERN_INFO "external SCSI bus reset detected\n");
218 writeb(CMD_NOP, ®s->command);
219 writel(RUN << 16, &dma->control); /* stop dma */
220 cmd_done(state, DID_RESET << 16);
223 if (intr & INTR_ILL_CMD) {
224 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
225 intr, stat, seq, state->phase);
226 cmd_done(state, DID_ERROR << 16);
229 if (stat & STAT_ERROR) {
231 /* XXX these seem to be harmless? */
232 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
233 intr, stat, seq, state->phase);
236 writeb(CMD_NOP + CMD_DMA_MODE, ®s->command);
239 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
242 if (stat & STAT_PARITY) {
243 printk(KERN_ERR "mac53c94: parity error\n");
244 cmd_done(state, DID_PARITY << 16);
247 switch (state->phase) {
249 if (intr & INTR_DISCONNECT) {
250 /* selection timed out */
251 cmd_done(state, DID_BAD_TARGET << 16);
254 if (intr != INTR_BUS_SERV + INTR_DONE) {
255 printk(KERN_DEBUG "got intr %x during selection\n", intr);
256 cmd_done(state, DID_ERROR << 16);
259 if ((seq & SS_MASK) != SS_DONE) {
260 printk(KERN_DEBUG "seq step %x after command\n", seq);
261 cmd_done(state, DID_ERROR << 16);
264 writeb(CMD_NOP, ®s->command);
265 /* set DMA controller going if any data to transfer */
266 if ((stat & (STAT_MSG|STAT_CD)) == 0
267 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
268 nb = cmd->SCp.this_residual;
271 cmd->SCp.this_residual -= nb;
272 writeb(nb, ®s->count_lo);
273 writeb(nb >> 8, ®s->count_mid);
274 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command);
275 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
276 writel((RUN << 16) | RUN, &dma->control);
277 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command);
278 state->phase = dataing;
280 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
281 /* up to status phase already */
282 writeb(CMD_I_COMPLETE, ®s->command);
283 state->phase = completing;
285 printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
287 cmd_done(state, DID_ERROR << 16);
293 if (intr != INTR_BUS_SERV) {
294 printk(KERN_DEBUG "got intr %x before status\n", intr);
295 cmd_done(state, DID_ERROR << 16);
298 if (cmd->SCp.this_residual != 0
299 && (stat & (STAT_MSG|STAT_CD)) == 0) {
300 /* Set up the count regs to transfer more */
301 nb = cmd->SCp.this_residual;
304 cmd->SCp.this_residual -= nb;
305 writeb(nb, ®s->count_lo);
306 writeb(nb >> 8, ®s->count_mid);
307 writeb(CMD_DMA_MODE + CMD_NOP, ®s->command);
308 writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command);
311 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
312 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
314 writel(RUN << 16, &dma->control); /* stop dma */
316 /* should check dma status */
317 writeb(CMD_I_COMPLETE, ®s->command);
318 state->phase = completing;
321 if (intr != INTR_DONE) {
322 printk(KERN_DEBUG "got intr %x on completion\n", intr);
323 cmd_done(state, DID_ERROR << 16);
326 cmd->SCp.Status = readb(®s->fifo);
327 cmd->SCp.Message = readb(®s->fifo);
328 cmd->result = CMD_ACCEPT_MSG;
329 writeb(CMD_ACCEPT_MSG, ®s->command);
330 state->phase = busfreeing;
333 if (intr != INTR_DISCONNECT) {
334 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
336 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
340 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
344 static void cmd_done(struct fsc_state *state, int result)
346 struct scsi_cmnd *cmd;
348 cmd = state->current_req;
350 cmd->result = result;
351 (*cmd->scsi_done)(cmd);
352 state->current_req = NULL;
355 mac53c94_start(state);
359 * Set up DMA commands for transferring data.
361 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
363 int i, dma_cmd, total, nseg;
364 struct scatterlist *scl;
365 struct dbdma_cmd *dcmds;
369 nseg = scsi_dma_map(cmd);
374 dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
375 OUTPUT_MORE : INPUT_MORE;
376 dcmds = state->dma_cmds;
379 scsi_for_each_sg(cmd, scl, nseg, i) {
380 dma_addr = sg_dma_address(scl);
381 dma_len = sg_dma_len(scl);
382 if (dma_len > 0xffff)
383 panic("mac53c94: scatterlist element >= 64k");
385 dcmds->req_count = cpu_to_le16(dma_len);
386 dcmds->command = cpu_to_le16(dma_cmd);
387 dcmds->phy_addr = cpu_to_le32(dma_addr);
388 dcmds->xfer_status = 0;
392 dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
393 dcmds[-1].command = cpu_to_le16(dma_cmd);
394 dcmds->command = cpu_to_le16(DBDMA_STOP);
395 cmd->SCp.this_residual = total;
398 static struct scsi_host_template mac53c94_template = {
399 .proc_name = "53c94",
401 .queuecommand = mac53c94_queue,
402 .eh_host_reset_handler = mac53c94_host_reset,
405 .sg_tablesize = SG_ALL,
406 .use_clustering = DISABLE_CLUSTERING,
409 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
411 struct device_node *node = macio_get_of_node(mdev);
412 struct pci_dev *pdev = macio_get_pci_dev(mdev);
413 struct fsc_state *state;
414 struct Scsi_Host *host;
416 const unsigned char *clkprop;
417 int proplen, rc = -ENODEV;
419 if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
420 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
422 macio_resource_count(mdev), macio_irq_count(mdev));
426 if (macio_request_resources(mdev, "mac53c94") != 0) {
427 printk(KERN_ERR "mac53c94: unable to request memory resources");
431 host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
433 printk(KERN_ERR "mac53c94: couldn't register host");
438 state = (struct fsc_state *) host->hostdata;
439 macio_set_drvdata(mdev, state);
444 state->regs = (struct mac53c94_regs __iomem *)
445 ioremap(macio_resource_start(mdev, 0), 0x1000);
446 state->intr = macio_irq(mdev, 0);
447 state->dma = (struct dbdma_regs __iomem *)
448 ioremap(macio_resource_start(mdev, 1), 0x1000);
449 state->dmaintr = macio_irq(mdev, 1);
450 if (state->regs == NULL || state->dma == NULL) {
451 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
456 clkprop = of_get_property(node, "clock-frequency", &proplen);
457 if (clkprop == NULL || proplen != sizeof(int)) {
458 printk(KERN_ERR "%s: can't get clock frequency, "
459 "assuming 25MHz\n", node->full_name);
460 state->clk_freq = 25000000;
462 state->clk_freq = *(int *)clkprop;
464 /* Space for dma command list: +1 for stop command,
465 * +1 to allow for aligning.
466 * XXX FIXME: Use DMA consistent routines
468 dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
469 sizeof(struct dbdma_cmd), GFP_KERNEL);
470 if (dma_cmd_space == 0) {
471 printk(KERN_ERR "mac53c94: couldn't allocate dma "
472 "command space for %s\n", node->full_name);
476 state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
477 memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
478 * sizeof(struct dbdma_cmd));
479 state->dma_cmd_space = dma_cmd_space;
481 mac53c94_init(state);
483 if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
484 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
485 state->intr, node->full_name);
489 rc = scsi_add_host(host, &mdev->ofdev.dev);
491 goto out_release_irq;
493 scsi_scan_host(host);
497 free_irq(state->intr, state);
499 kfree(state->dma_cmd_space);
501 if (state->dma != NULL)
503 if (state->regs != NULL)
504 iounmap(state->regs);
507 macio_release_resources(mdev);
512 static int mac53c94_remove(struct macio_dev *mdev)
514 struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
515 struct Scsi_Host *host = fp->host;
517 scsi_remove_host(host);
519 free_irq(fp->intr, fp);
525 kfree(fp->dma_cmd_space);
529 macio_release_resources(mdev);
535 static struct of_device_id mac53c94_match[] =
542 MODULE_DEVICE_TABLE (of, mac53c94_match);
544 static struct macio_driver mac53c94_driver =
548 .owner = THIS_MODULE,
549 .of_match_table = mac53c94_match,
551 .probe = mac53c94_probe,
552 .remove = mac53c94_remove,
556 static int __init init_mac53c94(void)
558 return macio_register_driver(&mac53c94_driver);
561 static void __exit exit_mac53c94(void)
563 return macio_unregister_driver(&mac53c94_driver);
566 module_init(init_mac53c94);
567 module_exit(exit_mac53c94);
569 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
570 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
571 MODULE_LICENSE("GPL");