/* 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/init.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);