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linux/drivers/scsi/mac_esp.c
Finn Thain da244654c6 [SCSI] mac_esp: fix for quadras with two esp chips 
On the Quadra 900 and 950 there are two ESP chips sharing one IRQ. Because
the shared IRQ is edge-triggered, we must make sure that an IRQ transition
from one chip doesn't go unnoticed when the shared IRQ is already active
due to the other. This patch prevents interrupts getting lost so that both
SCSI busses may be used simultaneously.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29 11:24:19 -06:00

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/* mac_esp.c: ESP front-end for Macintosh Quadra systems.
*
* Adapted from jazz_esp.c and the old mac_esp.c.
*
* The pseudo DMA algorithm is based on the one used in NetBSD.
* See sys/arch/mac68k/obio/esp.c for some background information.
*
* Copyright (C) 2007-2008 Finn Thain
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/nubus.h>
#include <asm/irq.h>
#include <asm/dma.h>
#include <asm/macints.h>
#include <asm/macintosh.h>
#include <scsi/scsi_host.h>
#include "esp_scsi.h"
#define DRV_MODULE_NAME "mac_esp"
#define PFX DRV_MODULE_NAME ": "
#define DRV_VERSION "1.000"
#define DRV_MODULE_RELDATE "Sept 15, 2007"
#define MAC_ESP_IO_BASE 0x50F00000
#define MAC_ESP_REGS_QUADRA (MAC_ESP_IO_BASE + 0x10000)
#define MAC_ESP_REGS_QUADRA2 (MAC_ESP_IO_BASE + 0xF000)
#define MAC_ESP_REGS_QUADRA3 (MAC_ESP_IO_BASE + 0x18000)
#define MAC_ESP_REGS_SPACING 0x402
#define MAC_ESP_PDMA_REG 0xF9800024
#define MAC_ESP_PDMA_REG_SPACING 0x4
#define MAC_ESP_PDMA_IO_OFFSET 0x100
#define esp_read8(REG) mac_esp_read8(esp, REG)
#define esp_write8(VAL, REG) mac_esp_write8(esp, VAL, REG)
struct mac_esp_priv {
struct esp *esp;
void __iomem *pdma_regs;
void __iomem *pdma_io;
int error;
};
static struct platform_device *internal_pdev, *external_pdev;
static struct esp *esp_chips[2];
#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
platform_get_drvdata((struct platform_device *) \
(esp->dev)))
static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
{
nubus_writeb(val, esp->regs + reg * 16);
}
static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
{
return nubus_readb(esp->regs + reg * 16);
}
/* For pseudo DMA and PIO we need the virtual address
* so this address mapping is the identity mapping.
*/
static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
size_t sz, int dir)
{
return (dma_addr_t)buf;
}
static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
int num_sg, int dir)
{
int i;
for (i = 0; i < num_sg; i++)
sg[i].dma_address = (u32)sg_virt(&sg[i]);
return num_sg;
}
static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
size_t sz, int dir)
{
/* Nothing to do. */
}
static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
int num_sg, int dir)
{
/* Nothing to do. */
}
static void mac_esp_reset_dma(struct esp *esp)
{
/* Nothing to do. */
}
static void mac_esp_dma_drain(struct esp *esp)
{
/* Nothing to do. */
}
static void mac_esp_dma_invalidate(struct esp *esp)
{
/* Nothing to do. */
}
static int mac_esp_dma_error(struct esp *esp)
{
return MAC_ESP_GET_PRIV(esp)->error;
}
static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
int i = 500000;
do {
if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
return 0;
if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
return 1;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
esp_read8(ESP_STATUS));
mep->error = 1;
return 1;
}
static inline int mac_esp_wait_for_dreq(struct esp *esp)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
int i = 500000;
do {
if (mep->pdma_regs == NULL) {
if (mac_irq_pending(IRQ_MAC_SCSIDRQ))
return 0;
} else {
if (nubus_readl(mep->pdma_regs) & 0x200)
return 0;
}
if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
return 1;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
esp_read8(ESP_STATUS));
mep->error = 1;
return 1;
}
#define MAC_ESP_PDMA_LOOP(operands) \
asm volatile ( \
" tstw %1 \n" \
" jbeq 20f \n" \
"1: movew " operands " \n" \
"2: movew " operands " \n" \
"3: movew " operands " \n" \
"4: movew " operands " \n" \
"5: movew " operands " \n" \
"6: movew " operands " \n" \
"7: movew " operands " \n" \
"8: movew " operands " \n" \
"9: movew " operands " \n" \
"10: movew " operands " \n" \
"11: movew " operands " \n" \
"12: movew " operands " \n" \
"13: movew " operands " \n" \
"14: movew " operands " \n" \
"15: movew " operands " \n" \
"16: movew " operands " \n" \
" subqw #1,%1 \n" \
" jbne 1b \n" \
"20: tstw %2 \n" \
" jbeq 30f \n" \
"21: movew " operands " \n" \
" subqw #1,%2 \n" \
" jbne 21b \n" \
"30: tstw %3 \n" \
" jbeq 40f \n" \
"31: moveb " operands " \n" \
"32: nop \n" \
"40: \n" \
" \n" \
" .section __ex_table,\"a\" \n" \
" .align 4 \n" \
" .long 1b,40b \n" \
" .long 2b,40b \n" \
" .long 3b,40b \n" \
" .long 4b,40b \n" \
" .long 5b,40b \n" \
" .long 6b,40b \n" \
" .long 7b,40b \n" \
" .long 8b,40b \n" \
" .long 9b,40b \n" \
" .long 10b,40b \n" \
" .long 11b,40b \n" \
" .long 12b,40b \n" \
" .long 13b,40b \n" \
" .long 14b,40b \n" \
" .long 15b,40b \n" \
" .long 16b,40b \n" \
" .long 21b,40b \n" \
" .long 31b,40b \n" \
" .long 32b,40b \n" \
" .previous \n" \
: "+a" (addr), "+r" (count32), "+r" (count2) \
: "g" (count1), "a" (mep->pdma_io))
static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
u32 dma_count, int write, u8 cmd)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
unsigned long flags;
local_irq_save(flags);
mep->error = 0;
if (!write)
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
scsi_esp_cmd(esp, cmd);
do {
unsigned int count32 = esp_count >> 5;
unsigned int count2 = (esp_count & 0x1F) >> 1;
unsigned int count1 = esp_count & 1;
unsigned int start_addr = addr;
if (mac_esp_wait_for_dreq(esp))
break;
if (write) {
MAC_ESP_PDMA_LOOP("%4@,%0@+");
esp_count -= addr - start_addr;
} else {
unsigned int n;
MAC_ESP_PDMA_LOOP("%0@+,%4@");
if (mac_esp_wait_for_empty_fifo(esp))
break;
n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
addr = start_addr + esp_count - n;
esp_count = n;
}
} while (esp_count);
local_irq_restore(flags);
}
/*
* Programmed IO routines follow.
*/
static inline int mac_esp_wait_for_fifo(struct esp *esp)
{
int i = 500000;
do {
if (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES)
return 0;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
esp_read8(ESP_STATUS));
return 1;
}
static inline int mac_esp_wait_for_intr(struct esp *esp)
{
int i = 500000;
do {
esp->sreg = esp_read8(ESP_STATUS);
if (esp->sreg & ESP_STAT_INTR)
return 0;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
return 1;
}
#define MAC_ESP_PIO_LOOP(operands, reg1) \
asm volatile ( \
"1: moveb " operands " \n" \
" subqw #1,%1 \n" \
" jbne 1b \n" \
: "+a" (addr), "+r" (reg1) \
: "a" (fifo))
#define MAC_ESP_PIO_FILL(operands, reg1) \
asm volatile ( \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" subqw #8,%1 \n" \
" subqw #8,%1 \n" \
: "+a" (addr), "+r" (reg1) \
: "a" (fifo))
#define MAC_ESP_FIFO_SIZE 16
static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
u32 dma_count, int write, u8 cmd)
{
unsigned long flags;
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
u8 *fifo = esp->regs + ESP_FDATA * 16;
local_irq_save(flags);
cmd &= ~ESP_CMD_DMA;
mep->error = 0;
if (write) {
scsi_esp_cmd(esp, cmd);
if (!mac_esp_wait_for_intr(esp)) {
if (mac_esp_wait_for_fifo(esp))
esp_count = 0;
} else {
esp_count = 0;
}
} else {
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
if (esp_count >= MAC_ESP_FIFO_SIZE)
MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
else
MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
scsi_esp_cmd(esp, cmd);
}
while (esp_count) {
unsigned int n;
if (mac_esp_wait_for_intr(esp)) {
mep->error = 1;
break;
}
if (esp->sreg & ESP_STAT_SPAM) {
printk(KERN_ERR PFX "gross error\n");
mep->error = 1;
break;
}
n = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
if (write) {
if (n > esp_count)
n = esp_count;
esp_count -= n;
MAC_ESP_PIO_LOOP("%2@,%0@+", n);
if ((esp->sreg & ESP_STAT_PMASK) == ESP_STATP)
break;
if (esp_count) {
esp->ireg = esp_read8(ESP_INTRPT);
if (esp->ireg & ESP_INTR_DC)
break;
scsi_esp_cmd(esp, ESP_CMD_TI);
}
} else {
esp->ireg = esp_read8(ESP_INTRPT);
if (esp->ireg & ESP_INTR_DC)
break;
n = MAC_ESP_FIFO_SIZE - n;
if (n > esp_count)
n = esp_count;
if (n == MAC_ESP_FIFO_SIZE) {
MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
} else {
esp_count -= n;
MAC_ESP_PIO_LOOP("%0@+,%2@", n);
}
scsi_esp_cmd(esp, ESP_CMD_TI);
}
}
local_irq_restore(flags);
}
static int mac_esp_irq_pending(struct esp *esp)
{
if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
return 1;
return 0;
}
static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
{
return dma_len > 0xFFFF ? 0xFFFF : dma_len;
}
static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
{
int got_intr;
/*
* This is an edge triggered IRQ, so we have to be careful to
* avoid missing a transition when it is shared by two ESP devices.
*/
do {
got_intr = 0;
if (esp_chips[0] &&
(mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
(void)scsi_esp_intr(irq, esp_chips[0]);
got_intr = 1;
}
if (esp_chips[1] &&
(mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
(void)scsi_esp_intr(irq, esp_chips[1]);
got_intr = 1;
}
} while (got_intr);
return IRQ_HANDLED;
}
static struct esp_driver_ops mac_esp_ops = {
.esp_write8 = mac_esp_write8,
.esp_read8 = mac_esp_read8,
.map_single = mac_esp_map_single,
.map_sg = mac_esp_map_sg,
.unmap_single = mac_esp_unmap_single,
.unmap_sg = mac_esp_unmap_sg,
.irq_pending = mac_esp_irq_pending,
.dma_length_limit = mac_esp_dma_length_limit,
.reset_dma = mac_esp_reset_dma,
.dma_drain = mac_esp_dma_drain,
.dma_invalidate = mac_esp_dma_invalidate,
.send_dma_cmd = mac_esp_send_pdma_cmd,
.dma_error = mac_esp_dma_error,
};
static int __devinit esp_mac_probe(struct platform_device *dev)
{
struct scsi_host_template *tpnt = &scsi_esp_template;
struct Scsi_Host *host;
struct esp *esp;
int err;
int chips_present;
struct mac_esp_priv *mep;
if (!MACH_IS_MAC)
return -ENODEV;
switch (macintosh_config->scsi_type) {
case MAC_SCSI_QUADRA:
case MAC_SCSI_QUADRA3:
chips_present = 1;
break;
case MAC_SCSI_QUADRA2:
if ((macintosh_config->ident == MAC_MODEL_Q900) ||
(macintosh_config->ident == MAC_MODEL_Q950))
chips_present = 2;
else
chips_present = 1;
break;
default:
chips_present = 0;
}
if (dev->id + 1 > chips_present)
return -ENODEV;
host = scsi_host_alloc(tpnt, sizeof(struct esp));
err = -ENOMEM;
if (!host)
goto fail;
host->max_id = 8;
host->use_clustering = DISABLE_CLUSTERING;
esp = shost_priv(host);
esp->host = host;
esp->dev = dev;
esp->command_block = kzalloc(16, GFP_KERNEL);
if (!esp->command_block)
goto fail_unlink;
esp->command_block_dma = (dma_addr_t)esp->command_block;
esp->scsi_id = 7;
host->this_id = esp->scsi_id;
esp->scsi_id_mask = 1 << esp->scsi_id;
mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
if (!mep)
goto fail_free_command_block;
mep->esp = esp;
platform_set_drvdata(dev, mep);
switch (macintosh_config->scsi_type) {
case MAC_SCSI_QUADRA:
esp->cfreq = 16500000;
esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA;
mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
mep->pdma_regs = NULL;
break;
case MAC_SCSI_QUADRA2:
esp->cfreq = 25000000;
esp->regs = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
dev->id * MAC_ESP_REGS_SPACING);
mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
dev->id * MAC_ESP_PDMA_REG_SPACING);
nubus_writel(0x1d1, mep->pdma_regs);
break;
case MAC_SCSI_QUADRA3:
/* These quadras have a real DMA controller (the PSC) but we
* don't know how to drive it so we must use PIO instead.
*/
esp->cfreq = 25000000;
esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA3;
mep->pdma_io = NULL;
mep->pdma_regs = NULL;
break;
}
esp->ops = &mac_esp_ops;
if (mep->pdma_io == NULL) {
printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
esp_write8(0, ESP_TCLOW);
esp_write8(0, ESP_TCMED);
esp->flags = ESP_FLAG_DISABLE_SYNC;
mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
} else {
printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
}
host->irq = IRQ_MAC_SCSI;
esp_chips[dev->id] = esp;
mb();
if (esp_chips[!dev->id] == NULL) {
err = request_irq(host->irq, mac_scsi_esp_intr, 0,
"Mac ESP", NULL);
if (err < 0) {
esp_chips[dev->id] = NULL;
goto fail_free_priv;
}
}
err = scsi_esp_register(esp, &dev->dev);
if (err)
goto fail_free_irq;
return 0;
fail_free_irq:
if (esp_chips[!dev->id] == NULL)
free_irq(host->irq, esp);
fail_free_priv:
kfree(mep);
fail_free_command_block:
kfree(esp->command_block);
fail_unlink:
scsi_host_put(host);
fail:
return err;
}
static int __devexit esp_mac_remove(struct platform_device *dev)
{
struct mac_esp_priv *mep = platform_get_drvdata(dev);
struct esp *esp = mep->esp;
unsigned int irq = esp->host->irq;
scsi_esp_unregister(esp);
esp_chips[dev->id] = NULL;
if (!(esp_chips[0] || esp_chips[1]))
free_irq(irq, NULL);
kfree(mep);
kfree(esp->command_block);
scsi_host_put(esp->host);
return 0;
}
static struct platform_driver esp_mac_driver = {
.probe = esp_mac_probe,
.remove = __devexit_p(esp_mac_remove),
.driver = {
.name = DRV_MODULE_NAME,
},
};
static int __init mac_esp_init(void)
{
int err;
err = platform_driver_register(&esp_mac_driver);
if (err)
return err;
internal_pdev = platform_device_alloc(DRV_MODULE_NAME, 0);
if (internal_pdev && platform_device_add(internal_pdev)) {
platform_device_put(internal_pdev);
internal_pdev = NULL;
}
external_pdev = platform_device_alloc(DRV_MODULE_NAME, 1);
if (external_pdev && platform_device_add(external_pdev)) {
platform_device_put(external_pdev);
external_pdev = NULL;
}
if (internal_pdev || external_pdev) {
return 0;
} else {
platform_driver_unregister(&esp_mac_driver);
return -ENOMEM;
}
}
static void __exit mac_esp_exit(void)
{
platform_driver_unregister(&esp_mac_driver);
if (internal_pdev) {
platform_device_unregister(internal_pdev);
internal_pdev = NULL;
}
if (external_pdev) {
platform_device_unregister(external_pdev);
external_pdev = NULL;
}
}
MODULE_DESCRIPTION("Mac ESP SCSI driver");
MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);
module_init(mac_esp_init);
module_exit(mac_esp_exit);
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