// SPDX-License-Identifier: GPL-2.0-only /* * SCSI low-level driver for the 53c94 SCSI bus adaptor found * on Power Macintosh computers, controlling the external SCSI chain. * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA) * controller. * * Paul Mackerras, August 1996. * Copyright (C) 1996 Paul Mackerras. */ #include <linux/kernel.h> #include <linux/delay.h> #include <linux/types.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/blkdev.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/spinlock.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/pci.h> #include <asm/dbdma.h> #include <asm/io.h> #include <asm/pgtable.h> #include <asm/prom.h> #include <asm/macio.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_device.h> #include <scsi/scsi_host.h> #include "mac53c94.h" enum fsc_phase { idle, selecting, dataing, completing, busfreeing, }; struct fsc_state { struct mac53c94_regs __iomem *regs; int intr; struct dbdma_regs __iomem *dma; int dmaintr; int clk_freq; struct Scsi_Host *host; struct scsi_cmnd *request_q; struct scsi_cmnd *request_qtail; struct scsi_cmnd *current_req; /* req we're currently working on */ enum fsc_phase phase; /* what we're currently trying to do */ struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */ void *dma_cmd_space; struct pci_dev *pdev; dma_addr_t dma_addr; struct macio_dev *mdev; }; static void mac53c94_init(struct fsc_state *); static void mac53c94_start(struct fsc_state *); static void mac53c94_interrupt(int, void *); static irqreturn_t do_mac53c94_interrupt(int, void *); static void cmd_done(struct fsc_state *, int result); static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *); static int mac53c94_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *)) { struct fsc_state *state; #if 0 if (cmd->sc_data_direction == DMA_TO_DEVICE) { int i; printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd); for (i = 0; i < cmd->cmd_len; ++i) printk(KERN_CONT " %.2x", cmd->cmnd[i]); printk(KERN_CONT "\n"); printk(KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n", scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd)); } #endif cmd->scsi_done = done; cmd->host_scribble = NULL; state = (struct fsc_state *) cmd->device->host->hostdata; if (state->request_q == NULL) state->request_q = cmd; else state->request_qtail->host_scribble = (void *) cmd; state->request_qtail = cmd; if (state->phase == idle) mac53c94_start(state); return 0; } static DEF_SCSI_QCMD(mac53c94_queue) static int mac53c94_host_reset(struct scsi_cmnd *cmd) { struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata; struct mac53c94_regs __iomem *regs = state->regs; struct dbdma_regs __iomem *dma = state->dma; unsigned long flags; spin_lock_irqsave(cmd->device->host->host_lock, flags); writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control); writeb(CMD_SCSI_RESET, ®s->command); /* assert RST */ udelay(100); /* leave it on for a while (>= 25us) */ writeb(CMD_RESET, ®s->command); udelay(20); mac53c94_init(state); writeb(CMD_NOP, ®s->command); spin_unlock_irqrestore(cmd->device->host->host_lock, flags); return SUCCESS; } static void mac53c94_init(struct fsc_state *state) { struct mac53c94_regs __iomem *regs = state->regs; struct dbdma_regs __iomem *dma = state->dma; int x; writeb(state->host->this_id | CF1_PAR_ENABLE, ®s->config1); writeb(TIMO_VAL(250), ®s->sel_timeout); /* 250ms */ writeb(CLKF_VAL(state->clk_freq), ®s->clk_factor); writeb(CF2_FEATURE_EN, ®s->config2); writeb(0, ®s->config3); writeb(0, ®s->sync_period); writeb(0, ®s->sync_offset); x = readb(®s->interrupt); writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control); } /* * Start the next command for a 53C94. * Should be called with interrupts disabled. */ static void mac53c94_start(struct fsc_state *state) { struct scsi_cmnd *cmd; struct mac53c94_regs __iomem *regs = state->regs; int i; if (state->phase != idle || state->current_req != NULL) panic("inappropriate mac53c94_start (state=%p)", state); if (state->request_q == NULL) return; state->current_req = cmd = state->request_q; state->request_q = (struct scsi_cmnd *) cmd->host_scribble; /* Off we go */ writeb(0, ®s->count_lo); writeb(0, ®s->count_mid); writeb(0, ®s->count_hi); writeb(CMD_NOP + CMD_DMA_MODE, ®s->command); udelay(1); writeb(CMD_FLUSH, ®s->command); udelay(1); writeb(cmd->device->id, ®s->dest_id); writeb(0, ®s->sync_period); writeb(0, ®s->sync_offset); /* load the command into the FIFO */ for (i = 0; i < cmd->cmd_len; ++i) writeb(cmd->cmnd[i], ®s->fifo); /* do select without ATN XXX */ writeb(CMD_SELECT, ®s->command); state->phase = selecting; set_dma_cmds(state, cmd); } static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id) { unsigned long flags; struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host; spin_lock_irqsave(dev->host_lock, flags); mac53c94_interrupt(irq, dev_id); spin_unlock_irqrestore(dev->host_lock, flags); return IRQ_HANDLED; } static void mac53c94_interrupt(int irq, void *dev_id) { struct fsc_state *state = (struct fsc_state *) dev_id; struct mac53c94_regs __iomem *regs = state->regs; struct dbdma_regs __iomem *dma = state->dma; struct scsi_cmnd *cmd = state->current_req; int nb, stat, seq, intr; static int mac53c94_errors; /* * Apparently, reading the interrupt register unlatches * the status and sequence step registers. */ seq = readb(®s->seqstep); stat = readb(®s->status); intr = readb(®s->interrupt); #if 0 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n", intr, stat, seq, state->phase); #endif if (intr & INTR_RESET) { /* SCSI bus was reset */ printk(KERN_INFO "external SCSI bus reset detected\n"); writeb(CMD_NOP, ®s->command); writel(RUN << 16, &dma->control); /* stop dma */ cmd_done(state, DID_RESET << 16); return; } if (intr & INTR_ILL_CMD) { printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n", intr, stat, seq, state->phase); cmd_done(state, DID_ERROR << 16); return; } if (stat & STAT_ERROR) { #if 0 /* XXX these seem to be harmless? */ printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n", intr, stat, seq, state->phase); #endif ++mac53c94_errors; writeb(CMD_NOP + CMD_DMA_MODE, ®s->command); } if (cmd == 0) { printk(KERN_DEBUG "53c94: interrupt with no command active?\n"); return; } if (stat & STAT_PARITY) { printk(KERN_ERR "mac53c94: parity error\n"); cmd_done(state, DID_PARITY << 16); return; } switch (state->phase) { case selecting: if (intr & INTR_DISCONNECT) { /* selection timed out */ cmd_done(state, DID_BAD_TARGET << 16); return; } if (intr != INTR_BUS_SERV + INTR_DONE) { printk(KERN_DEBUG "got intr %x during selection\n", intr); cmd_done(state, DID_ERROR << 16); return; } if ((seq & SS_MASK) != SS_DONE) { printk(KERN_DEBUG "seq step %x after command\n", seq); cmd_done(state, DID_ERROR << 16); return; } writeb(CMD_NOP, ®s->command); /* set DMA controller going if any data to transfer */ if ((stat & (STAT_MSG|STAT_CD)) == 0 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) { nb = cmd->SCp.this_residual; if (nb > 0xfff0) nb = 0xfff0; cmd->SCp.this_residual -= nb; writeb(nb, ®s->count_lo); writeb(nb >> 8, ®s->count_mid); writeb(CMD_DMA_MODE + CMD_NOP, ®s->command); writel(virt_to_phys(state->dma_cmds), &dma->cmdptr); writel((RUN << 16) | RUN, &dma->control); writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command); state->phase = dataing; break; } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) { /* up to status phase already */ writeb(CMD_I_COMPLETE, ®s->command); state->phase = completing; } else { printk(KERN_DEBUG "in unexpected phase %x after cmd\n", stat & STAT_PHASE); cmd_done(state, DID_ERROR << 16); return; } break; case dataing: if (intr != INTR_BUS_SERV) { printk(KERN_DEBUG "got intr %x before status\n", intr); cmd_done(state, DID_ERROR << 16); return; } if (cmd->SCp.this_residual != 0 && (stat & (STAT_MSG|STAT_CD)) == 0) { /* Set up the count regs to transfer more */ nb = cmd->SCp.this_residual; if (nb > 0xfff0) nb = 0xfff0; cmd->SCp.this_residual -= nb; writeb(nb, ®s->count_lo); writeb(nb >> 8, ®s->count_mid); writeb(CMD_DMA_MODE + CMD_NOP, ®s->command); writeb(CMD_DMA_MODE + CMD_XFER_DATA, ®s->command); break; } if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) { printk(KERN_DEBUG "intr %x before data xfer complete\n", intr); } writel(RUN << 16, &dma->control); /* stop dma */ scsi_dma_unmap(cmd); /* should check dma status */ writeb(CMD_I_COMPLETE, ®s->command); state->phase = completing; break; case completing: if (intr != INTR_DONE) { printk(KERN_DEBUG "got intr %x on completion\n", intr); cmd_done(state, DID_ERROR << 16); return; } cmd->SCp.Status = readb(®s->fifo); cmd->SCp.Message = readb(®s->fifo); cmd->result = CMD_ACCEPT_MSG; writeb(CMD_ACCEPT_MSG, ®s->command); state->phase = busfreeing; break; case busfreeing: if (intr != INTR_DISCONNECT) { printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr); } cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8) + cmd->SCp.Status); break; default: printk(KERN_DEBUG "don't know about phase %d\n", state->phase); } } static void cmd_done(struct fsc_state *state, int result) { struct scsi_cmnd *cmd; cmd = state->current_req; if (cmd != 0) { cmd->result = result; (*cmd->scsi_done)(cmd); state->current_req = NULL; } state->phase = idle; mac53c94_start(state); } /* * Set up DMA commands for transferring data. */ static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd) { int i, dma_cmd, total, nseg; struct scatterlist *scl; struct dbdma_cmd *dcmds; dma_addr_t dma_addr; u32 dma_len; nseg = scsi_dma_map(cmd); BUG_ON(nseg < 0); if (!nseg) return; dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ? OUTPUT_MORE : INPUT_MORE; dcmds = state->dma_cmds; total = 0; scsi_for_each_sg(cmd, scl, nseg, i) { dma_addr = sg_dma_address(scl); dma_len = sg_dma_len(scl); if (dma_len > 0xffff) panic("mac53c94: scatterlist element >= 64k"); total += dma_len; dcmds->req_count = cpu_to_le16(dma_len); dcmds->command = cpu_to_le16(dma_cmd); dcmds->phy_addr = cpu_to_le32(dma_addr); dcmds->xfer_status = 0; ++dcmds; } dma_cmd += OUTPUT_LAST - OUTPUT_MORE; dcmds[-1].command = cpu_to_le16(dma_cmd); dcmds->command = cpu_to_le16(DBDMA_STOP); cmd->SCp.this_residual = total; } static struct scsi_host_template mac53c94_template = { .proc_name = "53c94", .name = "53C94", .queuecommand = mac53c94_queue, .eh_host_reset_handler = mac53c94_host_reset, .can_queue = 1, .this_id = 7, .sg_tablesize = SG_ALL, .max_segment_size = 65535, }; static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match) { struct device_node *node = macio_get_of_node(mdev); struct pci_dev *pdev = macio_get_pci_dev(mdev); struct fsc_state *state; struct Scsi_Host *host; void *dma_cmd_space; const unsigned char *clkprop; int proplen, rc = -ENODEV; if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) { printk(KERN_ERR "mac53c94: expected 2 addrs and intrs" " (got %d/%d)\n", macio_resource_count(mdev), macio_irq_count(mdev)); return -ENODEV; } if (macio_request_resources(mdev, "mac53c94") != 0) { printk(KERN_ERR "mac53c94: unable to request memory resources"); return -EBUSY; } host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state)); if (host == NULL) { printk(KERN_ERR "mac53c94: couldn't register host"); rc = -ENOMEM; goto out_release; } state = (struct fsc_state *) host->hostdata; macio_set_drvdata(mdev, state); state->host = host; state->pdev = pdev; state->mdev = mdev; state->regs = (struct mac53c94_regs __iomem *) ioremap(macio_resource_start(mdev, 0), 0x1000); state->intr = macio_irq(mdev, 0); state->dma = (struct dbdma_regs __iomem *) ioremap(macio_resource_start(mdev, 1), 0x1000); state->dmaintr = macio_irq(mdev, 1); if (state->regs == NULL || state->dma == NULL) { printk(KERN_ERR "mac53c94: ioremap failed for %pOF\n", node); goto out_free; } clkprop = of_get_property(node, "clock-frequency", &proplen); if (clkprop == NULL || proplen != sizeof(int)) { printk(KERN_ERR "%pOF: can't get clock frequency, " "assuming 25MHz\n", node); state->clk_freq = 25000000; } else state->clk_freq = *(int *)clkprop; /* Space for dma command list: +1 for stop command, * +1 to allow for aligning. * XXX FIXME: Use DMA consistent routines */ dma_cmd_space = kmalloc_array(host->sg_tablesize + 2, sizeof(struct dbdma_cmd), GFP_KERNEL); if (dma_cmd_space == 0) { printk(KERN_ERR "mac53c94: couldn't allocate dma " "command space for %pOF\n", node); rc = -ENOMEM; goto out_free; } state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space); memset(state->dma_cmds, 0, (host->sg_tablesize + 1) * sizeof(struct dbdma_cmd)); state->dma_cmd_space = dma_cmd_space; mac53c94_init(state); if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) { printk(KERN_ERR "mac53C94: can't get irq %d for %pOF\n", state->intr, node); goto out_free_dma; } rc = scsi_add_host(host, &mdev->ofdev.dev); if (rc != 0) goto out_release_irq; scsi_scan_host(host); return 0; out_release_irq: free_irq(state->intr, state); out_free_dma: kfree(state->dma_cmd_space); out_free: if (state->dma != NULL) iounmap(state->dma); if (state->regs != NULL) iounmap(state->regs); scsi_host_put(host); out_release: macio_release_resources(mdev); return rc; } static int mac53c94_remove(struct macio_dev *mdev) { struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev); struct Scsi_Host *host = fp->host; scsi_remove_host(host); free_irq(fp->intr, fp); if (fp->regs) iounmap(fp->regs); if (fp->dma) iounmap(fp->dma); kfree(fp->dma_cmd_space); scsi_host_put(host); macio_release_resources(mdev); return 0; } static struct of_device_id mac53c94_match[] = { { .name = "53c94", }, {}, }; MODULE_DEVICE_TABLE (of, mac53c94_match); static struct macio_driver mac53c94_driver = { .driver = { .name = "mac53c94", .owner = THIS_MODULE, .of_match_table = mac53c94_match, }, .probe = mac53c94_probe, .remove = mac53c94_remove, }; static int __init init_mac53c94(void) { return macio_register_driver(&mac53c94_driver); } static void __exit exit_mac53c94(void) { return macio_unregister_driver(&mac53c94_driver); } module_init(init_mac53c94); module_exit(exit_mac53c94); MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver"); MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>"); MODULE_LICENSE("GPL");