diff options
Diffstat (limited to 'drivers/irqchip/irq-aspeed-vic.c')
| -rw-r--r-- | drivers/irqchip/irq-aspeed-vic.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-aspeed-vic.c b/drivers/irqchip/irq-aspeed-vic.c new file mode 100644 index 000000000000..d24451d5bf8a --- /dev/null +++ b/drivers/irqchip/irq-aspeed-vic.c @@ -0,0 +1,230 @@ +/* + * Copyright (C) 2015 - Ben Herrenschmidt, IBM Corp. + * + * Driver for Aspeed "new" VIC as found in SoC generation 3 and later + * + * Based on irq-vic.c: + * + * Copyright (C) 1999 - 2003 ARM Limited + * Copyright (C) 2000 Deep Blue Solutions Ltd + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/export.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/syscore_ops.h> +#include <linux/device.h> +#include <linux/slab.h> + +#include <asm/exception.h> +#include <asm/irq.h> + +/* These definitions correspond to the "new mapping" of the + * register set that interleaves "high" and "low". The offsets + * below are for the "low" register, add 4 to get to the high one + */ +#define AVIC_IRQ_STATUS 0x00 +#define AVIC_FIQ_STATUS 0x08 +#define AVIC_RAW_STATUS 0x10 +#define AVIC_INT_SELECT 0x18 +#define AVIC_INT_ENABLE 0x20 +#define AVIC_INT_ENABLE_CLR 0x28 +#define AVIC_INT_TRIGGER 0x30 +#define AVIC_INT_TRIGGER_CLR 0x38 +#define AVIC_INT_SENSE 0x40 +#define AVIC_INT_DUAL_EDGE 0x48 +#define AVIC_INT_EVENT 0x50 +#define AVIC_EDGE_CLR 0x58 +#define AVIC_EDGE_STATUS 0x60 + +#define NUM_IRQS 64 + +struct aspeed_vic { + void __iomem *base; + u32 edge_sources[2]; + struct irq_domain *dom; +}; +static struct aspeed_vic *system_avic; + +static void vic_init_hw(struct aspeed_vic *vic) +{ + u32 sense; + + /* Disable all interrupts */ + writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR); + writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR + 4); + + /* Make sure no soft trigger is on */ + writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR); + writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR + 4); + + /* Set everything to be IRQ */ + writel(0, vic->base + AVIC_INT_SELECT); + writel(0, vic->base + AVIC_INT_SELECT + 4); + + /* Some interrupts have a programable high/low level trigger + * (4 GPIO direct inputs), for now we assume this was configured + * by firmware. We read which ones are edge now. + */ + sense = readl(vic->base + AVIC_INT_SENSE); + vic->edge_sources[0] = ~sense; + sense = readl(vic->base + AVIC_INT_SENSE + 4); + vic->edge_sources[1] = ~sense; + + /* Clear edge detection latches */ + writel(0xffffffff, vic->base + AVIC_EDGE_CLR); + writel(0xffffffff, vic->base + AVIC_EDGE_CLR + 4); +} + +static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs) +{ + struct aspeed_vic *vic = system_avic; + u32 stat, irq; + + for (;;) { + irq = 0; + stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS); + if (!stat) { + stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS + 4); + irq = 32; + } + if (stat == 0) + break; + irq += ffs(stat) - 1; + handle_domain_irq(vic->dom, irq, regs); + } +} + +static void avic_ack_irq(struct irq_data *d) +{ + struct aspeed_vic *vic = irq_data_get_irq_chip_data(d); + unsigned int sidx = d->hwirq >> 5; + unsigned int sbit = 1u << (d->hwirq & 0x1f); + + /* Clear edge latch for edge interrupts, nop for level */ + if (vic->edge_sources[sidx] & sbit) + writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4); +} + +static void avic_mask_irq(struct irq_data *d) +{ + struct aspeed_vic *vic = irq_data_get_irq_chip_data(d); + unsigned int sidx = d->hwirq >> 5; + unsigned int sbit = 1u << (d->hwirq & 0x1f); + + writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4); +} + +static void avic_unmask_irq(struct irq_data *d) +{ + struct aspeed_vic *vic = irq_data_get_irq_chip_data(d); + unsigned int sidx = d->hwirq >> 5; + unsigned int sbit = 1u << (d->hwirq & 0x1f); + + writel(sbit, vic->base + AVIC_INT_ENABLE + sidx * 4); +} + +/* For level irq, faster than going through a nop "ack" and mask */ +static void avic_mask_ack_irq(struct irq_data *d) +{ + struct aspeed_vic *vic = irq_data_get_irq_chip_data(d); + unsigned int sidx = d->hwirq >> 5; + unsigned int sbit = 1u << (d->hwirq & 0x1f); + + /* First mask */ + writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4); + + /* Then clear edge latch for edge interrupts */ + if (vic->edge_sources[sidx] & sbit) + writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4); +} + +static struct irq_chip avic_chip = { + .name = "AVIC", + .irq_ack = avic_ack_irq, + .irq_mask = avic_mask_irq, + .irq_unmask = avic_unmask_irq, + .irq_mask_ack = avic_mask_ack_irq, +}; + +static int avic_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) +{ + struct aspeed_vic *vic = d->host_data; + unsigned int sidx = hwirq >> 5; + unsigned int sbit = 1u << (hwirq & 0x1f); + + /* Check if interrupt exists */ + if (sidx > 1) + return -EPERM; + + if (vic->edge_sources[sidx] & sbit) + irq_set_chip_and_handler(irq, &avic_chip, handle_edge_irq); + else + irq_set_chip_and_handler(irq, &avic_chip, handle_level_irq); + irq_set_chip_data(irq, vic); + irq_set_probe(irq); + return 0; +} + +static struct irq_domain_ops avic_dom_ops = { + .map = avic_map, + .xlate = irq_domain_xlate_onetwocell, +}; + +static int __init avic_of_init(struct device_node *node, + struct device_node *parent) +{ + void __iomem *regs; + struct aspeed_vic *vic; + + if (WARN(parent, "non-root Aspeed VIC not supported")) + return -EINVAL; + if (WARN(system_avic, "duplicate Aspeed VIC not supported")) + return -EINVAL; + + regs = of_iomap(node, 0); + if (WARN_ON(!regs)) + return -EIO; + + vic = kzalloc(sizeof(struct aspeed_vic), GFP_KERNEL); + if (WARN_ON(!vic)) { + iounmap(regs); + return -ENOMEM; + } + vic->base = regs; + + /* Initialize soures, all masked */ + vic_init_hw(vic); + + /* Ready to receive interrupts */ + system_avic = vic; + set_handle_irq(avic_handle_irq); + + /* Register our domain */ + vic->dom = irq_domain_add_simple(node, NUM_IRQS, 0, + &avic_dom_ops, vic); + + return 0; +} + +IRQCHIP_DECLARE(aspeed_new_vic, "aspeed,ast2400-vic", avic_of_init); |