[SPARC64]: Get PCI floppies fully functional again.

EBUS DMA fixes:
- Add EBUS_DMA_FLAG_TCI_DISABLE that the client can set if it
  wants only to hear device interrupts, not DMA complete ones.
- When initially resetting the EBUS DMA unit, put valid burst etc.
  encodings in the CSR register.  Not doing this appears to leave
  the attached ISA device in a weird state.

PCI FLOPPY fixes:
- Do ebus_dma_enable() before ebus_dma_request()
- In sun_pci_fd_set_dma_mode() do not forget to set the direction.
- Set EBUS_DMA_FLAG_TCI_DISABLE in ebus_dma flags.
- Make sure that in error paths sun_fdc/FCD1 will be -1 (invalid).

Thanks to Soyoung Park for loaning her Ultra5 to me so I could fix this.

arch/sparc64/kernel/ebus.c

@@ -58,12 +58,16 @@
 
 #define EBUS_DMA_RESET_TIMEOUT	10000
 
-static void __ebus_dma_reset(struct ebus_dma_info *p)
+static void __ebus_dma_reset(struct ebus_dma_info *p, int no_drain)
 {
 	int i;
 	u32 val = 0;
 
 	writel(EBDMA_CSR_RESET, p->regs + EBDMA_CSR);
+	udelay(1);
+
+	if (no_drain)
+		return;
 
 	for (i = EBUS_DMA_RESET_TIMEOUT; i > 0; i--) {
 		val = readl(p->regs + EBDMA_CSR);
@@ -78,7 +82,7 @@ static irqreturn_t ebus_dma_irq(int irq, void *dev_id, struct pt_regs *regs)
 {
 	struct ebus_dma_info *p = dev_id;
 	unsigned long flags;
-	u32 csr;
+	u32 csr = 0;
 
 	spin_lock_irqsave(&p->lock, flags);
 	csr = readl(p->regs + EBDMA_CSR);
@@ -98,20 +102,31 @@ static irqreturn_t ebus_dma_irq(int irq, void *dev_id, struct pt_regs *regs)
 	}
 
 	return IRQ_NONE;
+
 }
 
 int ebus_dma_register(struct ebus_dma_info *p)
 {
+	u32 csr;
+
 	if (!p->regs)
 		return -EINVAL;
-	if (p->flags & ~(EBUS_DMA_FLAG_USE_EBDMA_HANDLER))
+	if (p->flags & ~(EBUS_DMA_FLAG_USE_EBDMA_HANDLER |
+			 EBUS_DMA_FLAG_TCI_DISABLE))
 		return -EINVAL;
 	if ((p->flags & EBUS_DMA_FLAG_USE_EBDMA_HANDLER) && !p->callback)
 		return -EINVAL;
 	if (!strlen(p->name))
 		return -EINVAL;
 
-	__ebus_dma_reset(p);
+	__ebus_dma_reset(p, 1);
+
+	csr = EBDMA_CSR_BURST_SZ_16 | EBDMA_CSR_EN_CNT;
+
+	if (p->flags & EBUS_DMA_FLAG_TCI_DISABLE)
+		csr |= EBDMA_CSR_TCI_DIS;
+
+	writel(csr, p->regs + EBDMA_CSR);
 
 	return 0;
 }
@@ -201,14 +216,23 @@ EXPORT_SYMBOL(ebus_dma_request);
 void ebus_dma_prepare(struct ebus_dma_info *p, int write)
 {
 	unsigned long flags;
+	u32 csr;
 
 	spin_lock_irqsave(&p->lock, flags);
-	__ebus_dma_reset(p);
-	writel(EBDMA_CSR_INT_EN |
-	       ((write) ? EBDMA_CSR_WRITE : 0) |
+	__ebus_dma_reset(p, 0);
+
+	csr = (EBDMA_CSR_INT_EN |
 	       EBDMA_CSR_EN_CNT |
 	       EBDMA_CSR_BURST_SZ_16 |
-	       EBDMA_CSR_EN_NEXT, p->regs + EBDMA_CSR);
+	       EBDMA_CSR_EN_NEXT);
+
+	if (write)
+		csr |= EBDMA_CSR_WRITE;
+	if (p->flags & EBUS_DMA_FLAG_TCI_DISABLE)
+		csr |= EBDMA_CSR_TCI_DIS;
+
+	writel(csr, p->regs + EBDMA_CSR);
+
 	spin_unlock_irqrestore(&p->lock, flags);
 }
 EXPORT_SYMBOL(ebus_dma_prepare);
@@ -228,15 +252,17 @@ EXPORT_SYMBOL(ebus_dma_addr);
 void ebus_dma_enable(struct ebus_dma_info *p, int on)
 {
 	unsigned long flags;
-	u32 csr;
+	u32 orig_csr, csr;
 
 	spin_lock_irqsave(&p->lock, flags);
-	csr = readl(p->regs + EBDMA_CSR);
+	orig_csr = csr = readl(p->regs + EBDMA_CSR);
 	if (on)
 		csr |= EBDMA_CSR_EN_DMA;
 	else
 		csr &= ~EBDMA_CSR_EN_DMA;
-	writel(csr, p->regs + EBDMA_CSR);
+	if ((orig_csr & EBDMA_CSR_EN_DMA) !=
+	    (csr & EBDMA_CSR_EN_DMA))
+		writel(csr, p->regs + EBDMA_CSR);
 	spin_unlock_irqrestore(&p->lock, flags);
 }
 EXPORT_SYMBOL(ebus_dma_enable);

include/asm-sparc64/ebus.h

@@ -57,6 +57,7 @@ struct ebus_dma_info {
 
 	unsigned int	flags;
 #define EBUS_DMA_FLAG_USE_EBDMA_HANDLER		0x00000001
+#define EBUS_DMA_FLAG_TCI_DISABLE		0x00000002
 
 	/* These are only valid is EBUS_DMA_FLAG_USE_EBDMA_HANDLER is
 	 * set.

include/asm-sparc64/floppy.h

@@ -340,12 +340,12 @@ static void sun_pci_fd_enable_dma(void)
 			       sun_pci_dma_current.len,
 			       sun_pci_dma_current.direction);
 
+	ebus_dma_enable(&sun_pci_fd_ebus_dma, 1);
+
 	if (ebus_dma_request(&sun_pci_fd_ebus_dma,
 			     sun_pci_dma_current.addr,
 			     sun_pci_dma_current.len))
 		BUG();
-
-	ebus_dma_enable(&sun_pci_fd_ebus_dma, 1);
 }
 
 static void sun_pci_fd_disable_dma(void)
@@ -361,6 +361,11 @@ static void sun_pci_fd_disable_dma(void)
 
 static void sun_pci_fd_set_dma_mode(int mode)
 {
+	if (mode == DMA_MODE_WRITE)
+		sun_pci_dma_pending.direction = PCI_DMA_TODEVICE;
+	else
+		sun_pci_dma_pending.direction = PCI_DMA_FROMDEVICE;
+
 	ebus_dma_prepare(&sun_pci_fd_ebus_dma, mode != DMA_MODE_WRITE);
 }
 
@@ -630,11 +635,9 @@ static unsigned long __init sun_floppy_init(void)
 
 		prom_getproperty(edev->prom_node, "status",
 				 state, sizeof(state));
-		if(!strncmp(state, "disabled", 8))
+		if (!strncmp(state, "disabled", 8))
 			return 0;
 			
-		/* XXX ioremap */
-		sun_fdc = (struct sun_flpy_controller *)edev->resource[0].start;
 		FLOPPY_IRQ = edev->irqs[0];
 
 		/* Make sure the high density bit is set, some systems
@@ -646,11 +649,14 @@ static unsigned long __init sun_floppy_init(void)
 		sun_pci_ebus_dev = ebus->self;
 
 		spin_lock_init(&sun_pci_fd_ebus_dma.lock);
+
 		/* XXX ioremap */
 		sun_pci_fd_ebus_dma.regs = edev->resource[1].start;
 		if (!sun_pci_fd_ebus_dma.regs)
 			return 0;
-		sun_pci_fd_ebus_dma.flags = EBUS_DMA_FLAG_USE_EBDMA_HANDLER;
+
+		sun_pci_fd_ebus_dma.flags = (EBUS_DMA_FLAG_USE_EBDMA_HANDLER |
+					     EBUS_DMA_FLAG_TCI_DISABLE);
 		sun_pci_fd_ebus_dma.callback = sun_pci_fd_dma_callback;
 		sun_pci_fd_ebus_dma.client_cookie = NULL;
 		sun_pci_fd_ebus_dma.irq = FLOPPY_IRQ;
@@ -658,6 +664,9 @@ static unsigned long __init sun_floppy_init(void)
 		if (ebus_dma_register(&sun_pci_fd_ebus_dma))
 			return 0;
 
+		/* XXX ioremap */
+		sun_fdc = (struct sun_flpy_controller *)edev->resource[0].start;
+
 		sun_fdops.fd_inb = sun_pci_fd_inb;
 		sun_fdops.fd_outb = sun_pci_fd_outb;