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Release 4.14 drivers/irqchip/irq-bcm2835.c

Directory: drivers/irqchip
/*
 * Copyright 2010 Broadcom
 * Copyright 2012 Simon Arlott, Chris Boot, Stephen Warren
 *
 * 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.
 *
 * Quirk 1: Shortcut interrupts don't set the bank 1/2 register pending bits
 *
 * If an interrupt fires on bank 1 that isn't in the shortcuts list, bit 8
 * on bank 0 is set to signify that an interrupt in bank 1 has fired, and
 * to look in the bank 1 status register for more information.
 *
 * If an interrupt fires on bank 1 that _is_ in the shortcuts list, its
 * shortcut bit in bank 0 is set as well as its interrupt bit in the bank 1
 * status register, but bank 0 bit 8 is _not_ set.
 *
 * Quirk 2: You can't mask the register 1/2 pending interrupts
 *
 * In a proper cascaded interrupt controller, the interrupt lines with
 * cascaded interrupt controllers on them are just normal interrupt lines.
 * You can mask the interrupts and get on with things. With this controller
 * you can't do that.
 *
 * Quirk 3: The shortcut interrupts can't be (un)masked in bank 0
 *
 * Those interrupts that have shortcuts can only be masked/unmasked in
 * their respective banks' enable/disable registers. Doing so in the bank 0
 * enable/disable registers has no effect.
 *
 * The FIQ control register:
 *  Bits 0-6: IRQ (index in order of interrupts from banks 1, 2, then 0)
 *  Bit    7: Enable FIQ generation
 *  Bits  8+: Unused
 *
 * An interrupt must be disabled before configuring it for FIQ generation
 * otherwise both handlers will fire at the same time!
 */

#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>

#include <asm/exception.h>

/* Put the bank and irq (32 bits) into the hwirq */

#define MAKE_HWIRQ(b, n)	((b << 5) | (n))

#define HWIRQ_BANK(i)		(i >> 5)

#define HWIRQ_BIT(i)		BIT(i & 0x1f)


#define NR_IRQS_BANK0		8

#define BANK0_HWIRQ_MASK	0xff
/* Shortcuts can't be disabled so any unknown new ones need to be masked */

#define SHORTCUT1_MASK		0x00007c00

#define SHORTCUT2_MASK		0x001f8000

#define SHORTCUT_SHIFT		10

#define BANK1_HWIRQ		BIT(8)

#define BANK2_HWIRQ		BIT(9)

#define BANK0_VALID_MASK	(BANK0_HWIRQ_MASK | BANK1_HWIRQ | BANK2_HWIRQ \
                                        | SHORTCUT1_MASK | SHORTCUT2_MASK)


#define REG_FIQ_CONTROL		0x0c


#define NR_BANKS		3

#define IRQS_PER_BANK		32


static const int reg_pending[] __initconst = { 0x00, 0x04, 0x08 };

static const int reg_enable[] __initconst = { 0x18, 0x10, 0x14 };

static const int reg_disable[] __initconst = { 0x24, 0x1c, 0x20 };

static const int bank_irqs[] __initconst = { 8, 32, 32 };


static const int shortcuts[] = {
	7, 9, 10, 18, 19,		/* Bank 1 */
	21, 22, 23, 24, 25, 30		/* Bank 2 */
};


struct armctrl_ic {
	
void __iomem *base;
	
void __iomem *pending[NR_BANKS];
	
void __iomem *enable[NR_BANKS];
	
void __iomem *disable[NR_BANKS];
	
struct irq_domain *domain;
};


static struct armctrl_ic intc __read_mostly;
static void __exception_irq_entry bcm2835_handle_irq(
	struct pt_regs *regs);
static void bcm2836_chained_handle_irq(struct irq_desc *desc);


static void armctrl_mask_irq(struct irq_data *d) { writel_relaxed(HWIRQ_BIT(d->hwirq), intc.disable[HWIRQ_BANK(d->hwirq)]); }

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Simon Arlott33100.00%1100.00%
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static void armctrl_unmask_irq(struct irq_data *d) { writel_relaxed(HWIRQ_BIT(d->hwirq), intc.enable[HWIRQ_BANK(d->hwirq)]); }

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static struct irq_chip armctrl_chip = { .name = "ARMCTRL-level", .irq_mask = armctrl_mask_irq, .irq_unmask = armctrl_unmask_irq };
static int armctrl_xlate(struct irq_domain *d, struct device_node *ctrlr, const u32 *intspec, unsigned int intsize, unsigned long *out_hwirq, unsigned int *out_type) { if (WARN_ON(intsize != 2)) return -EINVAL; if (WARN_ON(intspec[0] >= NR_BANKS)) return -EINVAL; if (WARN_ON(intspec[1] >= IRQS_PER_BANK)) return -EINVAL; if (WARN_ON(intspec[0] == 0 && intspec[1] >= NR_IRQS_BANK0)) return -EINVAL; *out_hwirq = MAKE_HWIRQ(intspec[0], intspec[1]); *out_type = IRQ_TYPE_NONE; return 0; }

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static const struct irq_domain_ops armctrl_ops = { .xlate = armctrl_xlate };
static int __init armctrl_of_init(struct device_node *node, struct device_node *parent, bool is_2836) { void __iomem *base; int irq, b, i; base = of_iomap(node, 0); if (!base) panic("%pOF: unable to map IC registers\n", node); intc.domain = irq_domain_add_linear(node, MAKE_HWIRQ(NR_BANKS, 0), &armctrl_ops, NULL); if (!intc.domain) panic("%pOF: unable to create IRQ domain\n", node); for (b = 0; b < NR_BANKS; b++) { intc.pending[b] = base + reg_pending[b]; intc.enable[b] = base + reg_enable[b]; intc.disable[b] = base + reg_disable[b]; for (i = 0; i < bank_irqs[b]; i++) { irq = irq_create_mapping(intc.domain, MAKE_HWIRQ(b, i)); BUG_ON(irq <= 0); irq_set_chip_and_handler(irq, &armctrl_chip, handle_level_irq); irq_set_probe(irq); } } if (is_2836) { int parent_irq = irq_of_parse_and_map(node, 0); if (!parent_irq) { panic("%pOF: unable to get parent interrupt.\n", node); } irq_set_chained_handler(parent_irq, bcm2836_chained_handle_irq); } else { set_handle_irq(bcm2835_handle_irq); } return 0; }

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Simon Arlott19879.52%120.00%
Eric Anholt4216.87%120.00%
Axel Lin52.01%120.00%
Rob Herring41.61%240.00%
Total249100.00%5100.00%


static int __init bcm2835_armctrl_of_init(struct device_node *node, struct device_node *parent) { return armctrl_of_init(node, parent, false); }

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static int __init bcm2836_armctrl_of_init(struct device_node *node, struct device_node *parent) { return armctrl_of_init(node, parent, true); }

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Eric Anholt27100.00%1100.00%
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/* * Handle each interrupt across the entire interrupt controller. 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 u32 armctrl_translate_bank(int bank) { u32 stat = readl_relaxed(intc.pending[bank]); return MAKE_HWIRQ(bank, ffs(stat) - 1); }

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Simon Arlott2982.86%150.00%
Eric Anholt617.14%150.00%
Total35100.00%2100.00%


static u32 armctrl_translate_shortcut(int bank, u32 stat) { return MAKE_HWIRQ(bank, shortcuts[ffs(stat >> SHORTCUT_SHIFT) - 1]); }

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Eric Anholt413.33%150.00%
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static u32 get_next_armctrl_hwirq(void) { u32 stat = readl_relaxed(intc.pending[0]) & BANK0_VALID_MASK; if (stat == 0) return ~0; else if (stat & BANK0_HWIRQ_MASK) return MAKE_HWIRQ(0, ffs(stat & BANK0_HWIRQ_MASK) - 1); else if (stat & SHORTCUT1_MASK) return armctrl_translate_shortcut(1, stat & SHORTCUT1_MASK); else if (stat & SHORTCUT2_MASK) return armctrl_translate_shortcut(2, stat & SHORTCUT2_MASK); else if (stat & BANK1_HWIRQ) return armctrl_translate_bank(1); else if (stat & BANK2_HWIRQ) return armctrl_translate_bank(2); else BUG(); }

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Simon Arlott8974.79%133.33%
Eric Anholt2924.37%133.33%
Axel Lin10.84%133.33%
Total119100.00%3100.00%


static void __exception_irq_entry bcm2835_handle_irq( struct pt_regs *regs) { u32 hwirq; while ((hwirq = get_next_armctrl_hwirq()) != ~0) handle_domain_irq(intc.domain, hwirq, regs); }

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Eric Anholt3797.37%266.67%
Simon Arlott12.63%133.33%
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static void bcm2836_chained_handle_irq(struct irq_desc *desc) { u32 hwirq; while ((hwirq = get_next_armctrl_hwirq()) != ~0) generic_handle_irq(irq_linear_revmap(intc.domain, hwirq)); }

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Eric Anholt38100.00%1100.00%
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IRQCHIP_DECLARE(bcm2835_armctrl_ic, "brcm,bcm2835-armctrl-ic", bcm2835_armctrl_of_init); IRQCHIP_DECLARE(bcm2836_armctrl_ic, "brcm,bcm2836-armctrl-ic", bcm2836_armctrl_of_init);

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Simon Arlott79274.79%110.00%
Eric Anholt23021.72%330.00%
Axel Lin252.36%110.00%
Rob Herring40.38%220.00%
Nico Pitre40.38%110.00%
Joël Porquet30.28%110.00%
Krzysztof Kozlowski10.09%110.00%
Total1059100.00%10100.00%
Directory: drivers/irqchip
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