diff options
Diffstat (limited to 'drivers/irqchip/irq-vic.c')
| -rw-r--r-- | drivers/irqchip/irq-vic.c | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-vic.c b/drivers/irqchip/irq-vic.c new file mode 100644 index 000000000..74192f62d --- /dev/null +++ b/drivers/irqchip/irq-vic.c @@ -0,0 +1,546 @@ +/* + * linux/arch/arm/common/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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#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/amba/bus.h> +#include <linux/irqchip/arm-vic.h> + +#include <asm/exception.h> +#include <asm/irq.h> + +#define VIC_IRQ_STATUS 0x00 +#define VIC_FIQ_STATUS 0x04 +#define VIC_INT_SELECT 0x0c /* 1 = FIQ, 0 = IRQ */ +#define VIC_INT_SOFT 0x18 +#define VIC_INT_SOFT_CLEAR 0x1c +#define VIC_PROTECT 0x20 +#define VIC_PL190_VECT_ADDR 0x30 /* PL190 only */ +#define VIC_PL190_DEF_VECT_ADDR 0x34 /* PL190 only */ + +#define VIC_VECT_ADDR0 0x100 /* 0 to 15 (0..31 PL192) */ +#define VIC_VECT_CNTL0 0x200 /* 0 to 15 (0..31 PL192) */ +#define VIC_ITCR 0x300 /* VIC test control register */ + +#define VIC_VECT_CNTL_ENABLE (1 << 5) + +#define VIC_PL192_VECT_ADDR 0xF00 + +/** + * struct vic_device - VIC PM device + * @parent_irq: The parent IRQ number of the VIC if cascaded, or 0. + * @irq: The IRQ number for the base of the VIC. + * @base: The register base for the VIC. + * @valid_sources: A bitmask of valid interrupts + * @resume_sources: A bitmask of interrupts for resume. + * @resume_irqs: The IRQs enabled for resume. + * @int_select: Save for VIC_INT_SELECT. + * @int_enable: Save for VIC_INT_ENABLE. + * @soft_int: Save for VIC_INT_SOFT. + * @protect: Save for VIC_PROTECT. + * @domain: The IRQ domain for the VIC. + */ +struct vic_device { + void __iomem *base; + int irq; + u32 valid_sources; + u32 resume_sources; + u32 resume_irqs; + u32 int_select; + u32 int_enable; + u32 soft_int; + u32 protect; + struct irq_domain *domain; +}; + +/* we cannot allocate memory when VICs are initially registered */ +static struct vic_device vic_devices[CONFIG_ARM_VIC_NR]; + +static int vic_id; + +static void vic_handle_irq(struct pt_regs *regs); + +/** + * vic_init2 - common initialisation code + * @base: Base of the VIC. + * + * Common initialisation code for registration + * and resume. +*/ +static void vic_init2(void __iomem *base) +{ + int i; + + for (i = 0; i < 16; i++) { + void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4); + writel(VIC_VECT_CNTL_ENABLE | i, reg); + } + + writel(32, base + VIC_PL190_DEF_VECT_ADDR); +} + +#ifdef CONFIG_PM +static void resume_one_vic(struct vic_device *vic) +{ + void __iomem *base = vic->base; + + printk(KERN_DEBUG "%s: resuming vic at %p\n", __func__, base); + + /* re-initialise static settings */ + vic_init2(base); + + writel(vic->int_select, base + VIC_INT_SELECT); + writel(vic->protect, base + VIC_PROTECT); + + /* set the enabled ints and then clear the non-enabled */ + writel(vic->int_enable, base + VIC_INT_ENABLE); + writel(~vic->int_enable, base + VIC_INT_ENABLE_CLEAR); + + /* and the same for the soft-int register */ + + writel(vic->soft_int, base + VIC_INT_SOFT); + writel(~vic->soft_int, base + VIC_INT_SOFT_CLEAR); +} + +static void vic_resume(void) +{ + int id; + + for (id = vic_id - 1; id >= 0; id--) + resume_one_vic(vic_devices + id); +} + +static void suspend_one_vic(struct vic_device *vic) +{ + void __iomem *base = vic->base; + + printk(KERN_DEBUG "%s: suspending vic at %p\n", __func__, base); + + vic->int_select = readl(base + VIC_INT_SELECT); + vic->int_enable = readl(base + VIC_INT_ENABLE); + vic->soft_int = readl(base + VIC_INT_SOFT); + vic->protect = readl(base + VIC_PROTECT); + + /* set the interrupts (if any) that are used for + * resuming the system */ + + writel(vic->resume_irqs, base + VIC_INT_ENABLE); + writel(~vic->resume_irqs, base + VIC_INT_ENABLE_CLEAR); +} + +static int vic_suspend(void) +{ + int id; + + for (id = 0; id < vic_id; id++) + suspend_one_vic(vic_devices + id); + + return 0; +} + +static struct syscore_ops vic_syscore_ops = { + .suspend = vic_suspend, + .resume = vic_resume, +}; + +/** + * vic_pm_init - initicall to register VIC pm + * + * This is called via late_initcall() to register + * the resources for the VICs due to the early + * nature of the VIC's registration. +*/ +static int __init vic_pm_init(void) +{ + if (vic_id > 0) + register_syscore_ops(&vic_syscore_ops); + + return 0; +} +late_initcall(vic_pm_init); +#endif /* CONFIG_PM */ + +static struct irq_chip vic_chip; + +static int vic_irqdomain_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) +{ + struct vic_device *v = d->host_data; + + /* Skip invalid IRQs, only register handlers for the real ones */ + if (!(v->valid_sources & (1 << hwirq))) + return -EPERM; + irq_set_chip_and_handler(irq, &vic_chip, handle_level_irq); + irq_set_chip_data(irq, v->base); + irq_set_probe(irq); + return 0; +} + +/* + * Handle each interrupt in a single VIC. Returns non-zero if we've + * handled at least one interrupt. This reads the status register + * before handling each interrupt, which is necessary given that + * handle_IRQ may briefly re-enable interrupts for soft IRQ handling. + */ +static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs) +{ + u32 stat, irq; + int handled = 0; + + while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) { + irq = ffs(stat) - 1; + handle_domain_irq(vic->domain, irq, regs); + handled = 1; + } + + return handled; +} + +static void vic_handle_irq_cascaded(struct irq_desc *desc) +{ + u32 stat, hwirq; + struct irq_chip *host_chip = irq_desc_get_chip(desc); + struct vic_device *vic = irq_desc_get_handler_data(desc); + + chained_irq_enter(host_chip, desc); + + while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) { + hwirq = ffs(stat) - 1; + generic_handle_irq(irq_find_mapping(vic->domain, hwirq)); + } + + chained_irq_exit(host_chip, desc); +} + +/* + * Keep iterating over all registered VIC's until there are no pending + * interrupts. + */ +static void __exception_irq_entry vic_handle_irq(struct pt_regs *regs) +{ + int i, handled; + + do { + for (i = 0, handled = 0; i < vic_id; ++i) + handled |= handle_one_vic(&vic_devices[i], regs); + } while (handled); +} + +static const struct irq_domain_ops vic_irqdomain_ops = { + .map = vic_irqdomain_map, + .xlate = irq_domain_xlate_onetwocell, +}; + +/** + * vic_register() - Register a VIC. + * @base: The base address of the VIC. + * @parent_irq: The parent IRQ if cascaded, else 0. + * @irq: The base IRQ for the VIC. + * @valid_sources: bitmask of valid interrupts + * @resume_sources: bitmask of interrupts allowed for resume sources. + * @node: The device tree node associated with the VIC. + * + * Register the VIC with the system device tree so that it can be notified + * of suspend and resume requests and ensure that the correct actions are + * taken to re-instate the settings on resume. + * + * This also configures the IRQ domain for the VIC. + */ +static void __init vic_register(void __iomem *base, unsigned int parent_irq, + unsigned int irq, + u32 valid_sources, u32 resume_sources, + struct device_node *node) +{ + struct vic_device *v; + int i; + + if (vic_id >= ARRAY_SIZE(vic_devices)) { + printk(KERN_ERR "%s: too few VICs, increase CONFIG_ARM_VIC_NR\n", __func__); + return; + } + + v = &vic_devices[vic_id]; + v->base = base; + v->valid_sources = valid_sources; + v->resume_sources = resume_sources; + set_handle_irq(vic_handle_irq); + vic_id++; + + if (parent_irq) { + irq_set_chained_handler_and_data(parent_irq, + vic_handle_irq_cascaded, v); + } + + v->domain = irq_domain_add_simple(node, fls(valid_sources), irq, + &vic_irqdomain_ops, v); + /* create an IRQ mapping for each valid IRQ */ + for (i = 0; i < fls(valid_sources); i++) + if (valid_sources & (1 << i)) + irq_create_mapping(v->domain, i); + /* If no base IRQ was passed, figure out our allocated base */ + if (irq) + v->irq = irq; + else + v->irq = irq_find_mapping(v->domain, 0); +} + +static void vic_ack_irq(struct irq_data *d) +{ + void __iomem *base = irq_data_get_irq_chip_data(d); + unsigned int irq = d->hwirq; + writel(1 << irq, base + VIC_INT_ENABLE_CLEAR); + /* moreover, clear the soft-triggered, in case it was the reason */ + writel(1 << irq, base + VIC_INT_SOFT_CLEAR); +} + +static void vic_mask_irq(struct irq_data *d) +{ + void __iomem *base = irq_data_get_irq_chip_data(d); + unsigned int irq = d->hwirq; + writel(1 << irq, base + VIC_INT_ENABLE_CLEAR); +} + +static void vic_unmask_irq(struct irq_data *d) +{ + void __iomem *base = irq_data_get_irq_chip_data(d); + unsigned int irq = d->hwirq; + writel(1 << irq, base + VIC_INT_ENABLE); +} + +#if defined(CONFIG_PM) +static struct vic_device *vic_from_irq(unsigned int irq) +{ + struct vic_device *v = vic_devices; + unsigned int base_irq = irq & ~31; + int id; + + for (id = 0; id < vic_id; id++, v++) { + if (v->irq == base_irq) + return v; + } + + return NULL; +} + +static int vic_set_wake(struct irq_data *d, unsigned int on) +{ + struct vic_device *v = vic_from_irq(d->irq); + unsigned int off = d->hwirq; + u32 bit = 1 << off; + + if (!v) + return -EINVAL; + + if (!(bit & v->resume_sources)) + return -EINVAL; + + if (on) + v->resume_irqs |= bit; + else + v->resume_irqs &= ~bit; + + return 0; +} +#else +#define vic_set_wake NULL +#endif /* CONFIG_PM */ + +static struct irq_chip vic_chip = { + .name = "VIC", + .irq_ack = vic_ack_irq, + .irq_mask = vic_mask_irq, + .irq_unmask = vic_unmask_irq, + .irq_set_wake = vic_set_wake, +}; + +static void __init vic_disable(void __iomem *base) +{ + writel(0, base + VIC_INT_SELECT); + writel(0, base + VIC_INT_ENABLE); + writel(~0, base + VIC_INT_ENABLE_CLEAR); + writel(0, base + VIC_ITCR); + writel(~0, base + VIC_INT_SOFT_CLEAR); +} + +static void __init vic_clear_interrupts(void __iomem *base) +{ + unsigned int i; + + writel(0, base + VIC_PL190_VECT_ADDR); + for (i = 0; i < 19; i++) { + unsigned int value; + + value = readl(base + VIC_PL190_VECT_ADDR); + writel(value, base + VIC_PL190_VECT_ADDR); + } +} + +/* + * The PL190 cell from ARM has been modified by ST to handle 64 interrupts. + * The original cell has 32 interrupts, while the modified one has 64, + * replocating two blocks 0x00..0x1f in 0x20..0x3f. In that case + * the probe function is called twice, with base set to offset 000 + * and 020 within the page. We call this "second block". + */ +static void __init vic_init_st(void __iomem *base, unsigned int irq_start, + u32 vic_sources, struct device_node *node) +{ + unsigned int i; + int vic_2nd_block = ((unsigned long)base & ~PAGE_MASK) != 0; + + /* Disable all interrupts initially. */ + vic_disable(base); + + /* + * Make sure we clear all existing interrupts. The vector registers + * in this cell are after the second block of general registers, + * so we can address them using standard offsets, but only from + * the second base address, which is 0x20 in the page + */ + if (vic_2nd_block) { + vic_clear_interrupts(base); + + /* ST has 16 vectors as well, but we don't enable them by now */ + for (i = 0; i < 16; i++) { + void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4); + writel(0, reg); + } + + writel(32, base + VIC_PL190_DEF_VECT_ADDR); + } + + vic_register(base, 0, irq_start, vic_sources, 0, node); +} + +void __init __vic_init(void __iomem *base, int parent_irq, int irq_start, + u32 vic_sources, u32 resume_sources, + struct device_node *node) +{ + unsigned int i; + u32 cellid = 0; + enum amba_vendor vendor; + + /* Identify which VIC cell this one is, by reading the ID */ + for (i = 0; i < 4; i++) { + void __iomem *addr; + addr = (void __iomem *)((u32)base & PAGE_MASK) + 0xfe0 + (i * 4); + cellid |= (readl(addr) & 0xff) << (8 * i); + } + vendor = (cellid >> 12) & 0xff; + printk(KERN_INFO "VIC @%p: id 0x%08x, vendor 0x%02x\n", + base, cellid, vendor); + + switch(vendor) { + case AMBA_VENDOR_ST: + vic_init_st(base, irq_start, vic_sources, node); + return; + default: + printk(KERN_WARNING "VIC: unknown vendor, continuing anyways\n"); + /* fall through */ + case AMBA_VENDOR_ARM: + break; + } + + /* Disable all interrupts initially. */ + vic_disable(base); + + /* Make sure we clear all existing interrupts */ + vic_clear_interrupts(base); + + vic_init2(base); + + vic_register(base, parent_irq, irq_start, vic_sources, resume_sources, node); +} + +/** + * vic_init() - initialise a vectored interrupt controller + * @base: iomem base address + * @irq_start: starting interrupt number, must be muliple of 32 + * @vic_sources: bitmask of interrupt sources to allow + * @resume_sources: bitmask of interrupt sources to allow for resume + */ +void __init vic_init(void __iomem *base, unsigned int irq_start, + u32 vic_sources, u32 resume_sources) +{ + __vic_init(base, 0, irq_start, vic_sources, resume_sources, NULL); +} + +/** + * vic_init_cascaded() - initialise a cascaded vectored interrupt controller + * @base: iomem base address + * @parent_irq: the parent IRQ we're cascaded off + * @vic_sources: bitmask of interrupt sources to allow + * @resume_sources: bitmask of interrupt sources to allow for resume + * + * This returns the base for the new interrupts or negative on error. + */ +int __init vic_init_cascaded(void __iomem *base, unsigned int parent_irq, + u32 vic_sources, u32 resume_sources) +{ + struct vic_device *v; + + v = &vic_devices[vic_id]; + __vic_init(base, parent_irq, 0, vic_sources, resume_sources, NULL); + /* Return out acquired base */ + return v->irq; +} +EXPORT_SYMBOL_GPL(vic_init_cascaded); + +#ifdef CONFIG_OF +static int __init vic_of_init(struct device_node *node, + struct device_node *parent) +{ + void __iomem *regs; + u32 interrupt_mask = ~0; + u32 wakeup_mask = ~0; + + if (WARN(parent, "non-root VICs are not supported")) + return -EINVAL; + + regs = of_iomap(node, 0); + if (WARN_ON(!regs)) + return -EIO; + + of_property_read_u32(node, "valid-mask", &interrupt_mask); + of_property_read_u32(node, "valid-wakeup-mask", &wakeup_mask); + + /* + * Passing 0 as first IRQ makes the simple domain allocate descriptors + */ + __vic_init(regs, 0, 0, interrupt_mask, wakeup_mask, node); + + return 0; +} +IRQCHIP_DECLARE(arm_pl190_vic, "arm,pl190-vic", vic_of_init); +IRQCHIP_DECLARE(arm_pl192_vic, "arm,pl192-vic", vic_of_init); +IRQCHIP_DECLARE(arm_versatile_vic, "arm,versatile-vic", vic_of_init); +#endif /* CONFIG OF */ |