diff options
Diffstat (limited to 'arch/sparc/kernel/ebus.c')
| -rw-r--r-- | arch/sparc/kernel/ebus.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/arch/sparc/kernel/ebus.c b/arch/sparc/kernel/ebus.c new file mode 100644 index 000000000000..77dbf6d45faf --- /dev/null +++ b/arch/sparc/kernel/ebus.c @@ -0,0 +1,257 @@ +/* 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/module.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); |