diff options
Diffstat (limited to 'arch/mips/dec/ioasic-irq.c')
| -rw-r--r-- | arch/mips/dec/ioasic-irq.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/mips/dec/ioasic-irq.c b/arch/mips/dec/ioasic-irq.c new file mode 100644 index 000000000..e04d973ce --- /dev/null +++ b/arch/mips/dec/ioasic-irq.c @@ -0,0 +1,116 @@ +/* + * DEC I/O ASIC interrupts. + * + * Copyright (c) 2002, 2003, 2013 Maciej W. Rozycki + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/init.h> +#include <linux/irq.h> +#include <linux/types.h> + +#include <asm/dec/ioasic.h> +#include <asm/dec/ioasic_addrs.h> +#include <asm/dec/ioasic_ints.h> + +static int ioasic_irq_base; + +static void unmask_ioasic_irq(struct irq_data *d) +{ + u32 simr; + + simr = ioasic_read(IO_REG_SIMR); + simr |= (1 << (d->irq - ioasic_irq_base)); + ioasic_write(IO_REG_SIMR, simr); +} + +static void mask_ioasic_irq(struct irq_data *d) +{ + u32 simr; + + simr = ioasic_read(IO_REG_SIMR); + simr &= ~(1 << (d->irq - ioasic_irq_base)); + ioasic_write(IO_REG_SIMR, simr); +} + +static void ack_ioasic_irq(struct irq_data *d) +{ + mask_ioasic_irq(d); + fast_iob(); +} + +static struct irq_chip ioasic_irq_type = { + .name = "IO-ASIC", + .irq_ack = ack_ioasic_irq, + .irq_mask = mask_ioasic_irq, + .irq_mask_ack = ack_ioasic_irq, + .irq_unmask = unmask_ioasic_irq, +}; + +static void clear_ioasic_dma_irq(struct irq_data *d) +{ + u32 sir; + + sir = ~(1 << (d->irq - ioasic_irq_base)); + ioasic_write(IO_REG_SIR, sir); + fast_iob(); +} + +static struct irq_chip ioasic_dma_irq_type = { + .name = "IO-ASIC-DMA", + .irq_ack = clear_ioasic_dma_irq, + .irq_mask = mask_ioasic_irq, + .irq_unmask = unmask_ioasic_irq, + .irq_eoi = clear_ioasic_dma_irq, +}; + +/* + * I/O ASIC implements two kinds of DMA interrupts, informational and + * error interrupts. + * + * The formers do not stop DMA and should be cleared as soon as possible + * so that if they retrigger before the handler has completed, usually as + * a side effect of actions taken by the handler, then they are reissued. + * These use the `handle_edge_irq' handler that clears the request right + * away. + * + * The latters stop DMA and do not resume it until the interrupt has been + * cleared. This cannot be done until after a corrective action has been + * taken and this also means they will not retrigger. Therefore they use + * the `handle_fasteoi_irq' handler that only clears the request on the + * way out. Because MIPS processor interrupt inputs, one of which the I/O + * ASIC is cascaded to, are level-triggered it is recommended that error + * DMA interrupt action handlers are registered with the IRQF_ONESHOT flag + * set so that they are run with the interrupt line masked. + * + * This mask has `1' bits in the positions of informational interrupts. + */ +#define IO_IRQ_DMA_INFO \ + (IO_IRQ_MASK(IO_INR_SCC0A_RXDMA) | \ + IO_IRQ_MASK(IO_INR_SCC1A_RXDMA) | \ + IO_IRQ_MASK(IO_INR_ISDN_TXDMA) | \ + IO_IRQ_MASK(IO_INR_ISDN_RXDMA) | \ + IO_IRQ_MASK(IO_INR_ASC_DMA)) + +void __init init_ioasic_irqs(int base) +{ + int i; + + /* Mask interrupts. */ + ioasic_write(IO_REG_SIMR, 0); + fast_iob(); + + for (i = base; i < base + IO_INR_DMA; i++) + irq_set_chip_and_handler(i, &ioasic_irq_type, + handle_level_irq); + for (; i < base + IO_IRQ_LINES; i++) + irq_set_chip_and_handler(i, &ioasic_dma_irq_type, + 1 << (i - base) & IO_IRQ_DMA_INFO ? + handle_edge_irq : handle_fasteoi_irq); + + ioasic_irq_base = base; +} |