linux/drivers/irqchip/irq-ath79-misc.c
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   1/*
   2 *  Atheros AR71xx/AR724x/AR913x MISC interrupt controller
   3 *
   4 *  Copyright (C) 2015 Alban Bedel <albeu@free.fr>
   5 *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
   6 *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
   7 *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   8 *
   9 *  Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
  10 *
  11 *  This program is free software; you can redistribute it and/or modify it
  12 *  under the terms of the GNU General Public License version 2 as published
  13 *  by the Free Software Foundation.
  14 */
  15
  16#include <linux/irqchip.h>
  17#include <linux/irqchip/chained_irq.h>
  18#include <linux/of_address.h>
  19#include <linux/of_irq.h>
  20
  21#define AR71XX_RESET_REG_MISC_INT_STATUS        0
  22#define AR71XX_RESET_REG_MISC_INT_ENABLE        4
  23
  24#define ATH79_MISC_IRQ_COUNT                    32
  25
  26static void ath79_misc_irq_handler(struct irq_desc *desc)
  27{
  28        struct irq_domain *domain = irq_desc_get_handler_data(desc);
  29        struct irq_chip *chip = irq_desc_get_chip(desc);
  30        void __iomem *base = domain->host_data;
  31        u32 pending;
  32
  33        chained_irq_enter(chip, desc);
  34
  35        pending = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_STATUS) &
  36                  __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  37
  38        if (!pending) {
  39                spurious_interrupt();
  40                chained_irq_exit(chip, desc);
  41                return;
  42        }
  43
  44        while (pending) {
  45                int bit = __ffs(pending);
  46
  47                generic_handle_irq(irq_linear_revmap(domain, bit));
  48                pending &= ~BIT(bit);
  49        }
  50
  51        chained_irq_exit(chip, desc);
  52}
  53
  54static void ar71xx_misc_irq_unmask(struct irq_data *d)
  55{
  56        void __iomem *base = irq_data_get_irq_chip_data(d);
  57        unsigned int irq = d->hwirq;
  58        u32 t;
  59
  60        t = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  61        __raw_writel(t | BIT(irq), base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  62
  63        /* flush write */
  64        __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  65}
  66
  67static void ar71xx_misc_irq_mask(struct irq_data *d)
  68{
  69        void __iomem *base = irq_data_get_irq_chip_data(d);
  70        unsigned int irq = d->hwirq;
  71        u32 t;
  72
  73        t = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  74        __raw_writel(t & ~BIT(irq), base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  75
  76        /* flush write */
  77        __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
  78}
  79
  80static void ar724x_misc_irq_ack(struct irq_data *d)
  81{
  82        void __iomem *base = irq_data_get_irq_chip_data(d);
  83        unsigned int irq = d->hwirq;
  84        u32 t;
  85
  86        t = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_STATUS);
  87        __raw_writel(t & ~BIT(irq), base + AR71XX_RESET_REG_MISC_INT_STATUS);
  88
  89        /* flush write */
  90        __raw_readl(base + AR71XX_RESET_REG_MISC_INT_STATUS);
  91}
  92
  93static struct irq_chip ath79_misc_irq_chip = {
  94        .name           = "MISC",
  95        .irq_unmask     = ar71xx_misc_irq_unmask,
  96        .irq_mask       = ar71xx_misc_irq_mask,
  97};
  98
  99static int misc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 100{
 101        irq_set_chip_and_handler(irq, &ath79_misc_irq_chip, handle_level_irq);
 102        irq_set_chip_data(irq, d->host_data);
 103        return 0;
 104}
 105
 106static const struct irq_domain_ops misc_irq_domain_ops = {
 107        .xlate = irq_domain_xlate_onecell,
 108        .map = misc_map,
 109};
 110
 111static void __init ath79_misc_intc_domain_init(
 112        struct irq_domain *domain, int irq)
 113{
 114        void __iomem *base = domain->host_data;
 115
 116        /* Disable and clear all interrupts */
 117        __raw_writel(0, base + AR71XX_RESET_REG_MISC_INT_ENABLE);
 118        __raw_writel(0, base + AR71XX_RESET_REG_MISC_INT_STATUS);
 119
 120        irq_set_chained_handler_and_data(irq, ath79_misc_irq_handler, domain);
 121}
 122
 123static int __init ath79_misc_intc_of_init(
 124        struct device_node *node, struct device_node *parent)
 125{
 126        struct irq_domain *domain;
 127        void __iomem *base;
 128        int irq;
 129
 130        irq = irq_of_parse_and_map(node, 0);
 131        if (!irq) {
 132                pr_err("Failed to get MISC IRQ\n");
 133                return -EINVAL;
 134        }
 135
 136        base = of_iomap(node, 0);
 137        if (!base) {
 138                pr_err("Failed to get MISC IRQ registers\n");
 139                return -ENOMEM;
 140        }
 141
 142        domain = irq_domain_add_linear(node, ATH79_MISC_IRQ_COUNT,
 143                                &misc_irq_domain_ops, base);
 144        if (!domain) {
 145                pr_err("Failed to add MISC irqdomain\n");
 146                return -EINVAL;
 147        }
 148
 149        ath79_misc_intc_domain_init(domain, irq);
 150        return 0;
 151}
 152
 153static int __init ar7100_misc_intc_of_init(
 154        struct device_node *node, struct device_node *parent)
 155{
 156        ath79_misc_irq_chip.irq_mask_ack = ar71xx_misc_irq_mask;
 157        return ath79_misc_intc_of_init(node, parent);
 158}
 159
 160IRQCHIP_DECLARE(ar7100_misc_intc, "qca,ar7100-misc-intc",
 161                ar7100_misc_intc_of_init);
 162
 163static int __init ar7240_misc_intc_of_init(
 164        struct device_node *node, struct device_node *parent)
 165{
 166        ath79_misc_irq_chip.irq_ack = ar724x_misc_irq_ack;
 167        return ath79_misc_intc_of_init(node, parent);
 168}
 169
 170IRQCHIP_DECLARE(ar7240_misc_intc, "qca,ar7240-misc-intc",
 171                ar7240_misc_intc_of_init);
 172
 173void __init ath79_misc_irq_init(void __iomem *regs, int irq,
 174                                int irq_base, bool is_ar71xx)
 175{
 176        struct irq_domain *domain;
 177
 178        if (is_ar71xx)
 179                ath79_misc_irq_chip.irq_mask_ack = ar71xx_misc_irq_mask;
 180        else
 181                ath79_misc_irq_chip.irq_ack = ar724x_misc_irq_ack;
 182
 183        domain = irq_domain_add_legacy(NULL, ATH79_MISC_IRQ_COUNT,
 184                        irq_base, 0, &misc_irq_domain_ops, regs);
 185        if (!domain)
 186                panic("Failed to create MISC irqdomain");
 187
 188        ath79_misc_intc_domain_init(domain, irq);
 189}
 190