linux/drivers/irqchip/irq-sunxi-nmi.c
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   1/*
   2 * Allwinner A20/A31 SoCs NMI IRQ chip driver.
   3 *
   4 * Carlo Caione <carlo.caione@gmail.com>
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2.  This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10
  11#define DRV_NAME        "sunxi-nmi"
  12#define pr_fmt(fmt)     DRV_NAME ": " fmt
  13
  14#include <linux/bitops.h>
  15#include <linux/device.h>
  16#include <linux/io.h>
  17#include <linux/irq.h>
  18#include <linux/interrupt.h>
  19#include <linux/irqdomain.h>
  20#include <linux/of_irq.h>
  21#include <linux/of_address.h>
  22#include <linux/of_platform.h>
  23#include <linux/irqchip.h>
  24#include <linux/irqchip/chained_irq.h>
  25
  26#define SUNXI_NMI_SRC_TYPE_MASK 0x00000003
  27
  28enum {
  29        SUNXI_SRC_TYPE_LEVEL_LOW = 0,
  30        SUNXI_SRC_TYPE_EDGE_FALLING,
  31        SUNXI_SRC_TYPE_LEVEL_HIGH,
  32        SUNXI_SRC_TYPE_EDGE_RISING,
  33};
  34
  35struct sunxi_sc_nmi_reg_offs {
  36        u32 ctrl;
  37        u32 pend;
  38        u32 enable;
  39};
  40
  41static struct sunxi_sc_nmi_reg_offs sun7i_reg_offs = {
  42        .ctrl   = 0x00,
  43        .pend   = 0x04,
  44        .enable = 0x08,
  45};
  46
  47static struct sunxi_sc_nmi_reg_offs sun6i_reg_offs = {
  48        .ctrl   = 0x00,
  49        .pend   = 0x04,
  50        .enable = 0x34,
  51};
  52
  53static struct sunxi_sc_nmi_reg_offs sun9i_reg_offs = {
  54        .ctrl   = 0x00,
  55        .pend   = 0x08,
  56        .enable = 0x04,
  57};
  58
  59static inline void sunxi_sc_nmi_write(struct irq_chip_generic *gc, u32 off,
  60                                      u32 val)
  61{
  62        irq_reg_writel(gc, val, off);
  63}
  64
  65static inline u32 sunxi_sc_nmi_read(struct irq_chip_generic *gc, u32 off)
  66{
  67        return irq_reg_readl(gc, off);
  68}
  69
  70static void sunxi_sc_nmi_handle_irq(struct irq_desc *desc)
  71{
  72        struct irq_domain *domain = irq_desc_get_handler_data(desc);
  73        struct irq_chip *chip = irq_desc_get_chip(desc);
  74        unsigned int virq = irq_find_mapping(domain, 0);
  75
  76        chained_irq_enter(chip, desc);
  77        generic_handle_irq(virq);
  78        chained_irq_exit(chip, desc);
  79}
  80
  81static int sunxi_sc_nmi_set_type(struct irq_data *data, unsigned int flow_type)
  82{
  83        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  84        struct irq_chip_type *ct = gc->chip_types;
  85        u32 src_type_reg;
  86        u32 ctrl_off = ct->regs.type;
  87        unsigned int src_type;
  88        unsigned int i;
  89
  90        irq_gc_lock(gc);
  91
  92        switch (flow_type & IRQF_TRIGGER_MASK) {
  93        case IRQ_TYPE_EDGE_FALLING:
  94                src_type = SUNXI_SRC_TYPE_EDGE_FALLING;
  95                break;
  96        case IRQ_TYPE_EDGE_RISING:
  97                src_type = SUNXI_SRC_TYPE_EDGE_RISING;
  98                break;
  99        case IRQ_TYPE_LEVEL_HIGH:
 100                src_type = SUNXI_SRC_TYPE_LEVEL_HIGH;
 101                break;
 102        case IRQ_TYPE_NONE:
 103        case IRQ_TYPE_LEVEL_LOW:
 104                src_type = SUNXI_SRC_TYPE_LEVEL_LOW;
 105                break;
 106        default:
 107                irq_gc_unlock(gc);
 108                pr_err("Cannot assign multiple trigger modes to IRQ %d.\n",
 109                        data->irq);
 110                return -EBADR;
 111        }
 112
 113        irqd_set_trigger_type(data, flow_type);
 114        irq_setup_alt_chip(data, flow_type);
 115
 116        for (i = 0; i < gc->num_ct; i++, ct++)
 117                if (ct->type & flow_type)
 118                        ctrl_off = ct->regs.type;
 119
 120        src_type_reg = sunxi_sc_nmi_read(gc, ctrl_off);
 121        src_type_reg &= ~SUNXI_NMI_SRC_TYPE_MASK;
 122        src_type_reg |= src_type;
 123        sunxi_sc_nmi_write(gc, ctrl_off, src_type_reg);
 124
 125        irq_gc_unlock(gc);
 126
 127        return IRQ_SET_MASK_OK;
 128}
 129
 130static int __init sunxi_sc_nmi_irq_init(struct device_node *node,
 131                                        struct sunxi_sc_nmi_reg_offs *reg_offs)
 132{
 133        struct irq_domain *domain;
 134        struct irq_chip_generic *gc;
 135        unsigned int irq;
 136        unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 137        int ret;
 138
 139
 140        domain = irq_domain_add_linear(node, 1, &irq_generic_chip_ops, NULL);
 141        if (!domain) {
 142                pr_err("Could not register interrupt domain.\n");
 143                return -ENOMEM;
 144        }
 145
 146        ret = irq_alloc_domain_generic_chips(domain, 1, 2, DRV_NAME,
 147                                             handle_fasteoi_irq, clr, 0,
 148                                             IRQ_GC_INIT_MASK_CACHE);
 149        if (ret) {
 150                pr_err("Could not allocate generic interrupt chip.\n");
 151                goto fail_irqd_remove;
 152        }
 153
 154        irq = irq_of_parse_and_map(node, 0);
 155        if (irq <= 0) {
 156                pr_err("unable to parse irq\n");
 157                ret = -EINVAL;
 158                goto fail_irqd_remove;
 159        }
 160
 161        gc = irq_get_domain_generic_chip(domain, 0);
 162        gc->reg_base = of_io_request_and_map(node, 0, of_node_full_name(node));
 163        if (IS_ERR(gc->reg_base)) {
 164                pr_err("unable to map resource\n");
 165                ret = PTR_ERR(gc->reg_base);
 166                goto fail_irqd_remove;
 167        }
 168
 169        gc->chip_types[0].type                  = IRQ_TYPE_LEVEL_MASK;
 170        gc->chip_types[0].chip.irq_mask         = irq_gc_mask_clr_bit;
 171        gc->chip_types[0].chip.irq_unmask       = irq_gc_mask_set_bit;
 172        gc->chip_types[0].chip.irq_eoi          = irq_gc_ack_set_bit;
 173        gc->chip_types[0].chip.irq_set_type     = sunxi_sc_nmi_set_type;
 174        gc->chip_types[0].chip.flags            = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED;
 175        gc->chip_types[0].regs.ack              = reg_offs->pend;
 176        gc->chip_types[0].regs.mask             = reg_offs->enable;
 177        gc->chip_types[0].regs.type             = reg_offs->ctrl;
 178
 179        gc->chip_types[1].type                  = IRQ_TYPE_EDGE_BOTH;
 180        gc->chip_types[1].chip.name             = gc->chip_types[0].chip.name;
 181        gc->chip_types[1].chip.irq_ack          = irq_gc_ack_set_bit;
 182        gc->chip_types[1].chip.irq_mask         = irq_gc_mask_clr_bit;
 183        gc->chip_types[1].chip.irq_unmask       = irq_gc_mask_set_bit;
 184        gc->chip_types[1].chip.irq_set_type     = sunxi_sc_nmi_set_type;
 185        gc->chip_types[1].regs.ack              = reg_offs->pend;
 186        gc->chip_types[1].regs.mask             = reg_offs->enable;
 187        gc->chip_types[1].regs.type             = reg_offs->ctrl;
 188        gc->chip_types[1].handler               = handle_edge_irq;
 189
 190        sunxi_sc_nmi_write(gc, reg_offs->enable, 0);
 191        sunxi_sc_nmi_write(gc, reg_offs->pend, 0x1);
 192
 193        irq_set_chained_handler_and_data(irq, sunxi_sc_nmi_handle_irq, domain);
 194
 195        return 0;
 196
 197fail_irqd_remove:
 198        irq_domain_remove(domain);
 199
 200        return ret;
 201}
 202
 203static int __init sun6i_sc_nmi_irq_init(struct device_node *node,
 204                                        struct device_node *parent)
 205{
 206        return sunxi_sc_nmi_irq_init(node, &sun6i_reg_offs);
 207}
 208IRQCHIP_DECLARE(sun6i_sc_nmi, "allwinner,sun6i-a31-sc-nmi", sun6i_sc_nmi_irq_init);
 209
 210static int __init sun7i_sc_nmi_irq_init(struct device_node *node,
 211                                        struct device_node *parent)
 212{
 213        return sunxi_sc_nmi_irq_init(node, &sun7i_reg_offs);
 214}
 215IRQCHIP_DECLARE(sun7i_sc_nmi, "allwinner,sun7i-a20-sc-nmi", sun7i_sc_nmi_irq_init);
 216
 217static int __init sun9i_nmi_irq_init(struct device_node *node,
 218                                     struct device_node *parent)
 219{
 220        return sunxi_sc_nmi_irq_init(node, &sun9i_reg_offs);
 221}
 222IRQCHIP_DECLARE(sun9i_nmi, "allwinner,sun9i-a80-nmi", sun9i_nmi_irq_init);
 223