--- /dev/null
+/* ebus.c: EBUS DMA library code.
+ *
+ * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
+ * Copyright (C) 1999 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#include <asm/ebus_dma.h>
+#include <asm/io.h>
+
+#define EBDMA_CSR 0x00UL /* Control/Status */
+#define EBDMA_ADDR 0x04UL /* DMA Address */
+#define EBDMA_COUNT 0x08UL /* DMA Count */
+
+#define EBDMA_CSR_INT_PEND 0x00000001
+#define EBDMA_CSR_ERR_PEND 0x00000002
+#define EBDMA_CSR_DRAIN 0x00000004
+#define EBDMA_CSR_INT_EN 0x00000010
+#define EBDMA_CSR_RESET 0x00000080
+#define EBDMA_CSR_WRITE 0x00000100
+#define EBDMA_CSR_EN_DMA 0x00000200
+#define EBDMA_CSR_CYC_PEND 0x00000400
+#define EBDMA_CSR_DIAG_RD_DONE 0x00000800
+#define EBDMA_CSR_DIAG_WR_DONE 0x00001000
+#define EBDMA_CSR_EN_CNT 0x00002000
+#define EBDMA_CSR_TC 0x00004000
+#define EBDMA_CSR_DIS_CSR_DRN 0x00010000
+#define EBDMA_CSR_BURST_SZ_MASK 0x000c0000
+#define EBDMA_CSR_BURST_SZ_1 0x00080000
+#define EBDMA_CSR_BURST_SZ_4 0x00000000
+#define EBDMA_CSR_BURST_SZ_8 0x00040000
+#define EBDMA_CSR_BURST_SZ_16 0x000c0000
+#define EBDMA_CSR_DIAG_EN 0x00100000
+#define EBDMA_CSR_DIS_ERR_PEND 0x00400000
+#define EBDMA_CSR_TCI_DIS 0x00800000
+#define EBDMA_CSR_EN_NEXT 0x01000000
+#define EBDMA_CSR_DMA_ON 0x02000000
+#define EBDMA_CSR_A_LOADED 0x04000000
+#define EBDMA_CSR_NA_LOADED 0x08000000
+#define EBDMA_CSR_DEV_ID_MASK 0xf0000000
+
+#define EBUS_DMA_RESET_TIMEOUT 10000
+
+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);
+
+ if (!(val & (EBDMA_CSR_DRAIN | EBDMA_CSR_CYC_PEND)))
+ break;
+ udelay(10);
+ }
+}
+
+static irqreturn_t ebus_dma_irq(int irq, void *dev_id)
+{
+ struct ebus_dma_info *p = dev_id;
+ unsigned long flags;
+ u32 csr = 0;
+
+ spin_lock_irqsave(&p->lock, flags);
+ csr = readl(p->regs + EBDMA_CSR);
+ writel(csr, p->regs + EBDMA_CSR);
+ spin_unlock_irqrestore(&p->lock, flags);
+
+ if (csr & EBDMA_CSR_ERR_PEND) {
+ printk(KERN_CRIT "ebus_dma(%s): DMA error!\n", p->name);
+ p->callback(p, EBUS_DMA_EVENT_ERROR, p->client_cookie);
+ return IRQ_HANDLED;
+ } else if (csr & EBDMA_CSR_INT_PEND) {
+ p->callback(p,
+ (csr & EBDMA_CSR_TC) ?
+ EBUS_DMA_EVENT_DMA : EBUS_DMA_EVENT_DEVICE,
+ p->client_cookie);
+ return IRQ_HANDLED;
+ }
+
+ 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 |
+ 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, 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;
+}
+EXPORT_SYMBOL(ebus_dma_register);
+
+int ebus_dma_irq_enable(struct ebus_dma_info *p, int on)
+{
+ unsigned long flags;
+ u32 csr;
+
+ if (on) {
+ if (p->flags & EBUS_DMA_FLAG_USE_EBDMA_HANDLER) {
+ if (request_irq(p->irq, ebus_dma_irq, IRQF_SHARED, p->name, p))
+ return -EBUSY;
+ }
+
+ spin_lock_irqsave(&p->lock, flags);
+ csr = readl(p->regs + EBDMA_CSR);
+ csr |= EBDMA_CSR_INT_EN;
+ writel(csr, p->regs + EBDMA_CSR);
+ spin_unlock_irqrestore(&p->lock, flags);
+ } else {
+ spin_lock_irqsave(&p->lock, flags);
+ csr = readl(p->regs + EBDMA_CSR);
+ csr &= ~EBDMA_CSR_INT_EN;
+ writel(csr, p->regs + EBDMA_CSR);
+ spin_unlock_irqrestore(&p->lock, flags);
+
+ if (p->flags & EBUS_DMA_FLAG_USE_EBDMA_HANDLER) {
+ free_irq(p->irq, p);
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(ebus_dma_irq_enable);
+
+void ebus_dma_unregister(struct ebus_dma_info *p)
+{
+ unsigned long flags;
+ u32 csr;
+ int irq_on = 0;
+
+ spin_lock_irqsave(&p->lock, flags);
+ csr = readl(p->regs + EBDMA_CSR);
+ if (csr & EBDMA_CSR_INT_EN) {
+ csr &= ~EBDMA_CSR_INT_EN;
+ writel(csr, p->regs + EBDMA_CSR);
+ irq_on = 1;
+ }
+ spin_unlock_irqrestore(&p->lock, flags);
+
+ if (irq_on)
+ free_irq(p->irq, p);
+}
+EXPORT_SYMBOL(ebus_dma_unregister);
+
+int ebus_dma_request(struct ebus_dma_info *p, dma_addr_t bus_addr, size_t len)
+{
+ unsigned long flags;
+ u32 csr;
+ int err;
+
+ if (len >= (1 << 24))
+ return -EINVAL;
+
+ spin_lock_irqsave(&p->lock, flags);
+ csr = readl(p->regs + EBDMA_CSR);
+ err = -EINVAL;
+ if (!(csr & EBDMA_CSR_EN_DMA))
+ goto out;
+ err = -EBUSY;
+ if (csr & EBDMA_CSR_NA_LOADED)
+ goto out;
+
+ writel(len, p->regs + EBDMA_COUNT);
+ writel(bus_addr, p->regs + EBDMA_ADDR);
+ err = 0;
+
+out:
+ spin_unlock_irqrestore(&p->lock, flags);
+
+ return err;
+}
+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, 0);
+
+ csr = (EBDMA_CSR_INT_EN |
+ EBDMA_CSR_EN_CNT |
+ EBDMA_CSR_BURST_SZ_16 |
+ 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);
+
+unsigned int ebus_dma_residue(struct ebus_dma_info *p)
+{
+ return readl(p->regs + EBDMA_COUNT);
+}
+EXPORT_SYMBOL(ebus_dma_residue);
+
+unsigned int ebus_dma_addr(struct ebus_dma_info *p)
+{
+ return readl(p->regs + EBDMA_ADDR);
+}
+EXPORT_SYMBOL(ebus_dma_addr);
+
+void ebus_dma_enable(struct ebus_dma_info *p, int on)
+{
+ unsigned long flags;
+ u32 orig_csr, csr;
+
+ spin_lock_irqsave(&p->lock, flags);
+ orig_csr = csr = readl(p->regs + EBDMA_CSR);
+ if (on)
+ csr |= EBDMA_CSR_EN_DMA;
+ else
+ csr &= ~EBDMA_CSR_EN_DMA;
+ 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);
Code Review / kvmfornfv.git / blobdiff