/*
* 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 <asm/dbdma.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/system.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 *, struct pt_regs *);
static irqreturn_t do_mac53c94_interrupt(int, void *, struct pt_regs *);
static void cmd_done(struct fsc_state *, int result);
static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
static int mac53c94_queue(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(" %.2x", cmd->cmnd[i]);
printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
cmd->use_sg, cmd->request_bufflen, cmd->request_buffer);
}
#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 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;
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);
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;
if (cmd->use_sg > 0 || cmd->request_bufflen != 0)
set_dma_cmds(state, cmd);
}
static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
{
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, ptregs);
spin_unlock_irqrestore(dev->host_lock, flags);
return IRQ_HANDLED;
}
static void mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
{
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
&& (cmd->use_sg > 0 || cmd->request_bufflen != 0)) {
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 */
if (cmd->use_sg != 0) {
pci_unmap_sg(state->pdev,
(struct scatterlist *)cmd->request_buffer,
cmd->use_sg, cmd->sc_data_direction);
} else {
pci_unmap_single(state->pdev, state->dma_addr,
cmd->request_bufflen, cmd->sc_data_direction);
}
/* 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;
struct scatterlist *scl;
struct dbdma_cmd *dcmds;
dma_addr_t dma_addr;
u32 dma_len;
dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
OUTPUT_MORE : INPUT_MORE;
dcmds = state->dma_cmds;
if (cmd->use_sg > 0) {
int nseg;
total = 0;
scl = (struct scatterlist *) cmd->buffer;
nseg = pci_map_sg(state->pdev, scl, cmd->use_sg,
cmd->sc_data_direction);
for (i = 0; i < 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;
st_le16(&dcmds->req_count, dma_len);
st_le16(&dcmds->command, dma_cmd);
st_le32(&dcmds->phy_addr, dma_addr);
dcmds->xfer_status = 0;
++scl;
++dcmds;
}
} else {
total = cmd->request_bufflen;
if (total > 0xffff)
panic("mac53c94: transfer size >= 64k");
dma_addr = pci_map_single(state->pdev, cmd->request_buffer,
total, cmd->sc_data_direction);
state->dma_addr = dma_addr;
st_le16(&dcmds->req_count, total);
st_le32(&dcmds->phy_addr, dma_addr);
dcmds->xfer_status = 0;
++dcmds;
}
dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
st_le16(&dcmds[-1].command, dma_cmd);
st_le16(&dcmds->command, 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_match *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;
unsigned char *clkprop;
int proplen;
if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
printk(KERN_ERR "mac53c94: expected 2 addrs and intrs (got %d/%d)\n",
node->n_addrs, node->n_intrs);
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");
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 = 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);
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;
}
/* XXX FIXME: handle failure */
scsi_add_host(host, &mdev->ofdev.dev);
scsi_scan_host(host);
return 0;
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 -ENODEV;
}
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((void *) fp->regs);
if (fp->dma)
iounmap((void *) fp->dma);
kfree(fp->dma_cmd_space);
scsi_host_put(host);
macio_release_resources(mdev);
return 0;
}
static struct of_match mac53c94_match[] =
{
{
.name = "53c94",
.type = OF_ANY_MATCH,
.compatible = OF_ANY_MATCH
},
{},
};
static struct macio_driver mac53c94_driver =
{
.name = "mac53c94",
.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");
