diff options
Diffstat (limited to 'c/src/lib/libbsp/powerpc/mcp750/irq/i8259.c')
| -rw-r--r-- | c/src/lib/libbsp/powerpc/mcp750/irq/i8259.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/powerpc/mcp750/irq/i8259.c b/c/src/lib/libbsp/powerpc/mcp750/irq/i8259.c new file mode 100644 index 0000000000..ae4f94dfea --- /dev/null +++ b/c/src/lib/libbsp/powerpc/mcp750/irq/i8259.c @@ -0,0 +1,152 @@ +/* i8259.c + * + * This file contains the implementation of the function described in irq.h + * related to Intel 8259 Programmable Interrupt controller. + * + * CopyRight (C) 1998 valette@crf.canon.fr + * + * The license and distribution terms for this file may be + * found in found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * $Id$ + */ + + +#include <bsp.h> +#include <bsp/irq.h> + +/*-------------------------------------------------------------------------+ +| Cache for 1st and 2nd PIC IRQ line's status (enabled or disabled) register. ++--------------------------------------------------------------------------*/ +/* + * lower byte is interrupt mask on the master PIC. + * while upper bits are interrupt on the slave PIC. + * This cache is initialized in ldseg.s + */ +volatile rtems_i8259_masks i8259s_cache; + +/*-------------------------------------------------------------------------+ +| Function: BSP_irq_disable_at_i8259s +| Description: Mask IRQ line in appropriate PIC chip. +| Global Variables: i8259s_cache +| Arguments: vector_offset - number of IRQ line to mask. +| Returns: Nothing. ++--------------------------------------------------------------------------*/ +int BSP_irq_disable_at_i8259s (const rtems_irq_symbolic_name irqLine) +{ + unsigned short mask; + unsigned int level; + + if ( ((int)irqLine < BSP_ISA_IRQ_LOWEST_OFFSET) || + ((int)irqLine > BSP_ISA_IRQ_MAX_OFFSET) + ) + return 1; + + _CPU_ISR_Disable(level); + + mask = 1 << irqLine; + i8259s_cache |= mask; + + if (irqLine < 8) + { + outport_byte(PIC_MASTER_IMR_IO_PORT, i8259s_cache & 0xff); + } + else + { + outport_byte(PIC_SLAVE_IMR_IO_PORT, ((i8259s_cache & 0xff00) > 8)); + } + _CPU_ISR_Enable (level); + + return 0; +} + +/*-------------------------------------------------------------------------+ +| Function: BSP_irq_enable_at_i8259s +| Description: Unmask IRQ line in appropriate PIC chip. +| Global Variables: i8259s_cache +| Arguments: irqLine - number of IRQ line to mask. +| Returns: Nothing. ++--------------------------------------------------------------------------*/ +int BSP_irq_enable_at_i8259s (const rtems_irq_symbolic_name irqLine) +{ + unsigned short mask; + unsigned int level; + + if ( ((int)irqLine < BSP_ISA_IRQ_LOWEST_OFFSET) || + ((int)irqLine > BSP_ISA_IRQ_MAX_OFFSET ) + ) + return 1; + + _CPU_ISR_Disable(level); + + mask = ~(1 << irqLine); + i8259s_cache &= mask; + + if (irqLine < 8) + { + outport_byte(PIC_MASTER_IMR_IO_PORT, i8259s_cache & 0xff); + } + else + { + outport_byte(PIC_SLAVE_IMR_IO_PORT, ((i8259s_cache & 0xff00) > 8)); + } + _CPU_ISR_Enable (level); + + return 0; +} /* mask_irq */ + +int BSP_irq_enabled_at_i8259s (const rtems_irq_symbolic_name irqLine) +{ + unsigned short mask; + + if ( ((int)irqLine < BSP_ISA_IRQ_LOWEST_OFFSET) || + ((int)irqLine > BSP_ISA_IRQ_MAX_OFFSET) + ) + return 1; + + mask = (1 << irqLine); + return (~(i8259s_cache & mask)); +} + + +/*-------------------------------------------------------------------------+ +| Function: BSP_irq_ack_at_i8259s +| Description: Signal generic End Of Interrupt (EOI) to appropriate PIC. +| Global Variables: None. +| Arguments: irqLine - number of IRQ line to acknowledge. +| Returns: Nothing. ++--------------------------------------------------------------------------*/ +int BSP_irq_ack_at_i8259s (const rtems_irq_symbolic_name irqLine) +{ + if (irqLine >= 8) { + outport_byte(PIC_SLAVE_COMMAND_IO_PORT, PIC_EOI); + } + outport_byte(PIC_MASTER_COMMAND_IO_PORT, PIC_EOI); + + return 0; + +} /* ackIRQ */ + +void BSP_i8259s_init(void) +{ + /* + * init master 8259 interrupt controller + */ + outport_byte(PIC_MASTER_COMMAND_IO_PORT, 0x11); /* Start init sequence */ + outport_byte(PIC_MASTER_IMR_IO_PORT, 0x00);/* Vector base = 0 */ + outport_byte(PIC_MASTER_IMR_IO_PORT, 0x04);/* edge tiggered, Cascade (slave) on IRQ2 */ + outport_byte(PIC_MASTER_IMR_IO_PORT, 0x01);/* Select 8086 mode */ + outport_byte(PIC_MASTER_IMR_IO_PORT, 0xFB); /* Mask all except cascade */ + /* + * init slave interrupt controller + */ + outport_byte(PIC_SLAVE_COMMAND_IO_PORT, 0x11); /* Start init sequence */ + outport_byte(PIC_SLAVE_IMR_IO_PORT, 0x08);/* Vector base = 8 */ + outport_byte(PIC_SLAVE_IMR_IO_PORT, 0x02);/* edge triggered, Cascade (slave) on IRQ2 */ + outport_byte(PIC_SLAVE_IMR_IO_PORT, 0x01); /* Select 8086 mode */ + outport_byte(PIC_SLAVE_IMR_IO_PORT, 0xFF); /* Mask all */ + + i8259s_cache = 0xFFFB; +} + |