diff options
Diffstat (limited to 'drivers/irqchip/irq-xilinx-intc.c')
| -rw-r--r-- | drivers/irqchip/irq-xilinx-intc.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-xilinx-intc.c b/drivers/irqchip/irq-xilinx-intc.c new file mode 100644 index 0000000000..238d3d3449 --- /dev/null +++ b/drivers/irqchip/irq-xilinx-intc.c @@ -0,0 +1,250 @@ +/* + * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2012-2013 Xilinx, Inc. + * Copyright (C) 2007-2009 PetaLogix + * Copyright (C) 2006 Atmark Techno, Inc. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/irqdomain.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/of_address.h> +#include <linux/io.h> +#include <linux/jump_label.h> +#include <linux/bug.h> +#include <linux/of_irq.h> + +/* No one else should require these constants, so define them locally here. */ +#define ISR 0x00 /* Interrupt Status Register */ +#define IPR 0x04 /* Interrupt Pending Register */ +#define IER 0x08 /* Interrupt Enable Register */ +#define IAR 0x0c /* Interrupt Acknowledge Register */ +#define SIE 0x10 /* Set Interrupt Enable bits */ +#define CIE 0x14 /* Clear Interrupt Enable bits */ +#define IVR 0x18 /* Interrupt Vector Register */ +#define MER 0x1c /* Master Enable Register */ + +#define MER_ME (1<<0) +#define MER_HIE (1<<1) + +#define SPURIOUS_IRQ (-1U) + +static DEFINE_STATIC_KEY_FALSE(xintc_is_be); + +struct xintc_irq_chip { + void __iomem *base; + struct irq_domain *root_domain; + u32 intr_mask; + u32 nr_irq; +}; + +static struct xintc_irq_chip *primary_intc; + +static void xintc_write(struct xintc_irq_chip *irqc, int reg, u32 data) +{ + if (static_branch_unlikely(&xintc_is_be)) + iowrite32be(data, irqc->base + reg); + else + iowrite32(data, irqc->base + reg); +} + +static u32 xintc_read(struct xintc_irq_chip *irqc, int reg) +{ + if (static_branch_unlikely(&xintc_is_be)) + return ioread32be(irqc->base + reg); + else + return ioread32(irqc->base + reg); +} + +static void intc_enable_or_unmask(struct irq_data *d) +{ + struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d); + unsigned long mask = BIT(d->hwirq); + + pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq); + + /* ack level irqs because they can't be acked during + * ack function since the handle_level_irq function + * acks the irq before calling the interrupt handler + */ + if (irqd_is_level_type(d)) + xintc_write(irqc, IAR, mask); + + xintc_write(irqc, SIE, mask); +} + +static void intc_disable_or_mask(struct irq_data *d) +{ + struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d); + + pr_debug("irq-xilinx: disable: %ld\n", d->hwirq); + xintc_write(irqc, CIE, BIT(d->hwirq)); +} + +static void intc_ack(struct irq_data *d) +{ + struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d); + + pr_debug("irq-xilinx: ack: %ld\n", d->hwirq); + xintc_write(irqc, IAR, BIT(d->hwirq)); +} + +static void intc_mask_ack(struct irq_data *d) +{ + struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d); + unsigned long mask = BIT(d->hwirq); + + pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq); + xintc_write(irqc, CIE, mask); + xintc_write(irqc, IAR, mask); +} + +static struct irq_chip intc_dev = { + .name = "Xilinx INTC", + .irq_unmask = intc_enable_or_unmask, + .irq_mask = intc_disable_or_mask, + .irq_ack = intc_ack, + .irq_mask_ack = intc_mask_ack, +}; + +static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) +{ + struct xintc_irq_chip *irqc = d->host_data; + + if (irqc->intr_mask & BIT(hw)) { + irq_set_chip_and_handler_name(irq, &intc_dev, + handle_edge_irq, "edge"); + irq_clear_status_flags(irq, IRQ_LEVEL); + } else { + irq_set_chip_and_handler_name(irq, &intc_dev, + handle_level_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } + irq_set_chip_data(irq, irqc); + return 0; +} + +static const struct irq_domain_ops xintc_irq_domain_ops = { + .xlate = irq_domain_xlate_onetwocell, + .map = xintc_map, +}; + +static void xil_intc_irq_handler(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct xintc_irq_chip *irqc; + + irqc = irq_data_get_irq_handler_data(&desc->irq_data); + chained_irq_enter(chip, desc); + do { + u32 hwirq = xintc_read(irqc, IVR); + + if (hwirq == -1U) + break; + + generic_handle_domain_irq(irqc->root_domain, hwirq); + } while (true); + chained_irq_exit(chip, desc); +} + +static void xil_intc_handle_irq(struct pt_regs *regs) +{ + u32 hwirq; + + do { + hwirq = xintc_read(primary_intc, IVR); + if (unlikely(hwirq == SPURIOUS_IRQ)) + break; + + generic_handle_domain_irq(primary_intc->root_domain, hwirq); + } while (true); +} + +static int __init xilinx_intc_of_init(struct device_node *intc, + struct device_node *parent) +{ + struct xintc_irq_chip *irqc; + int ret, irq; + + irqc = kzalloc(sizeof(*irqc), GFP_KERNEL); + if (!irqc) + return -ENOMEM; + irqc->base = of_iomap(intc, 0); + BUG_ON(!irqc->base); + + ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &irqc->nr_irq); + if (ret < 0) { + pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n"); + goto error; + } + + ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask); + if (ret < 0) { + pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n"); + irqc->intr_mask = 0; + } + + if (irqc->intr_mask >> irqc->nr_irq) + pr_warn("irq-xilinx: mismatch in kind-of-intr param\n"); + + pr_info("irq-xilinx: %pOF: num_irq=%d, edge=0x%x\n", + intc, irqc->nr_irq, irqc->intr_mask); + + + /* + * Disable all external interrupts until they are + * explicitly requested. + */ + xintc_write(irqc, IER, 0); + + /* Acknowledge any pending interrupts just in case. */ + xintc_write(irqc, IAR, 0xffffffff); + + /* Turn on the Master Enable. */ + xintc_write(irqc, MER, MER_HIE | MER_ME); + if (xintc_read(irqc, MER) != (MER_HIE | MER_ME)) { + static_branch_enable(&xintc_is_be); + xintc_write(irqc, MER, MER_HIE | MER_ME); + } + + irqc->root_domain = irq_domain_add_linear(intc, irqc->nr_irq, + &xintc_irq_domain_ops, irqc); + if (!irqc->root_domain) { + pr_err("irq-xilinx: Unable to create IRQ domain\n"); + ret = -EINVAL; + goto error; + } + + if (parent) { + irq = irq_of_parse_and_map(intc, 0); + if (irq) { + irq_set_chained_handler_and_data(irq, + xil_intc_irq_handler, + irqc); + } else { + pr_err("irq-xilinx: interrupts property not in DT\n"); + ret = -EINVAL; + goto error; + } + } else { + primary_intc = irqc; + irq_set_default_host(primary_intc->root_domain); + set_handle_irq(xil_intc_handle_irq); + } + + return 0; + +error: + iounmap(irqc->base); + kfree(irqc); + return ret; + +} + +IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init); +IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init); |