--- /dev/null
+/*
+ * 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 <asm/dbdma.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/prom.h>
+#include <asm/pci-bridge.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,
+ .cmd_per_lun = 1,
+ .use_clustering = DISABLE_CLUSTERING,
+};
+
+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 %s\n",
+ node->full_name);
+ goto out_free;
+ }
+
+ clkprop = of_get_property(node, "clock-frequency", &proplen);
+ if (clkprop == NULL || proplen != sizeof(int)) {
+ printk(KERN_ERR "%s: can't get clock frequency, "
+ "assuming 25MHz\n", node->full_name);
+ 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((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 %s\n", node->full_name);
+ 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 %s\n",
+ state->intr, node->full_name);
+ 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");
Code Review / kvmfornfv.git / blobdiff