diff options
Diffstat (limited to 'arch/powerpc/sysdev/xilinx_intc.c')
| -rw-r--r-- | arch/powerpc/sysdev/xilinx_intc.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c new file mode 100644 index 000000000000..c2f17cc43dfa --- /dev/null +++ b/arch/powerpc/sysdev/xilinx_intc.c @@ -0,0 +1,151 @@ +/* + * Interrupt controller driver for Xilinx Virtex FPGAs + * + * Copyright (C) 2007 Secret Lab Technologies Ltd. + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + * + */ + +/* + * This is a driver for the interrupt controller typically found in + * Xilinx Virtex FPGA designs. + * + * The interrupt sense levels are hard coded into the FPGA design with + * typically a 1:1 relationship between irq lines and devices (no shared + * irq lines). Therefore, this driver does not attempt to handle edge + * and level interrupts differently. + */ +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/irq.h> +#include <linux/of.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/irq.h> + +/* + * INTC Registers + */ +#define XINTC_ISR 0 /* Interrupt Status */ +#define XINTC_IPR 4 /* Interrupt Pending */ +#define XINTC_IER 8 /* Interrupt Enable */ +#define XINTC_IAR 12 /* Interrupt Acknowledge */ +#define XINTC_SIE 16 /* Set Interrupt Enable bits */ +#define XINTC_CIE 20 /* Clear Interrupt Enable bits */ +#define XINTC_IVR 24 /* Interrupt Vector */ +#define XINTC_MER 28 /* Master Enable */ + +static struct irq_host *master_irqhost; + +/* + * IRQ Chip operations + */ +static void xilinx_intc_mask(unsigned int virq) +{ + int irq = virq_to_hw(virq); + void * regs = get_irq_chip_data(virq); + pr_debug("mask: %d\n", irq); + out_be32(regs + XINTC_CIE, 1 << irq); +} + +static void xilinx_intc_unmask(unsigned int virq) +{ + int irq = virq_to_hw(virq); + void * regs = get_irq_chip_data(virq); + pr_debug("unmask: %d\n", irq); + out_be32(regs + XINTC_SIE, 1 << irq); +} + +static void xilinx_intc_ack(unsigned int virq) +{ + int irq = virq_to_hw(virq); + void * regs = get_irq_chip_data(virq); + pr_debug("ack: %d\n", irq); + out_be32(regs + XINTC_IAR, 1 << irq); +} + +static struct irq_chip xilinx_intc_irqchip = { + .typename = "Xilinx INTC", + .mask = xilinx_intc_mask, + .unmask = xilinx_intc_unmask, + .ack = xilinx_intc_ack, +}; + +/* + * IRQ Host operations + */ +static int xilinx_intc_map(struct irq_host *h, unsigned int virq, + irq_hw_number_t irq) +{ + set_irq_chip_data(virq, h->host_data); + set_irq_chip_and_handler(virq, &xilinx_intc_irqchip, handle_level_irq); + set_irq_type(virq, IRQ_TYPE_NONE); + return 0; +} + +static struct irq_host_ops xilinx_intc_ops = { + .map = xilinx_intc_map, +}; + +struct irq_host * __init +xilinx_intc_init(struct device_node *np) +{ + struct irq_host * irq; + struct resource res; + void * regs; + int rc; + + /* Find and map the intc registers */ + rc = of_address_to_resource(np, 0, &res); + if (rc) { + printk(KERN_ERR __FILE__ ": of_address_to_resource() failed\n"); + return NULL; + } + regs = ioremap(res.start, 32); + + printk(KERN_INFO "Xilinx intc at 0x%08X mapped to 0x%p\n", + res.start, regs); + + /* Setup interrupt controller */ + out_be32(regs + XINTC_IER, 0); /* disable all irqs */ + out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */ + out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */ + + /* Allocate and initialize an irq_host structure. */ + irq = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 32, &xilinx_intc_ops, -1); + if (!irq) + panic(__FILE__ ": Cannot allocate IRQ host\n"); + irq->host_data = regs; + return irq; +} + +int xilinx_intc_get_irq(void) +{ + void * regs = master_irqhost->host_data; + pr_debug("get_irq:\n"); + return irq_linear_revmap(master_irqhost, in_be32(regs + XINTC_IVR)); +} + +void __init xilinx_intc_init_tree(void) +{ + struct device_node *np; + + /* find top level interrupt controller */ + for_each_compatible_node(np, NULL, "xilinx,intc") { + if (!of_get_property(np, "interrupts", NULL)) + break; + } + + /* xilinx interrupt controller needs to be top level */ + BUG_ON(!np); + + master_irqhost = xilinx_intc_init(np); + BUG_ON(!master_irqhost); + + irq_set_default_host(master_irqhost); + of_node_put(np); +} |