linux/drivers/mfd/lp8788-irq.c
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   1/*
   2 * TI LP8788 MFD - interrupt handler
   3 *
   4 * Copyright 2012 Texas Instruments
   5 *
   6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 *
  12 */
  13
  14#include <linux/delay.h>
  15#include <linux/err.h>
  16#include <linux/interrupt.h>
  17#include <linux/irq.h>
  18#include <linux/irqdomain.h>
  19#include <linux/device.h>
  20#include <linux/mfd/lp8788.h>
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23
  24/* register address */
  25#define LP8788_INT_1                    0x00
  26#define LP8788_INTEN_1                  0x03
  27
  28#define BASE_INTEN_ADDR                 LP8788_INTEN_1
  29#define SIZE_REG                        8
  30#define NUM_REGS                        3
  31
  32/*
  33 * struct lp8788_irq_data
  34 * @lp               : used for accessing to lp8788 registers
  35 * @irq_lock         : mutex for enabling/disabling the interrupt
  36 * @domain           : IRQ domain for handling nested interrupt
  37 * @enabled          : status of enabled interrupt
  38 */
  39struct lp8788_irq_data {
  40        struct lp8788 *lp;
  41        struct mutex irq_lock;
  42        struct irq_domain *domain;
  43        int enabled[LP8788_INT_MAX];
  44};
  45
  46static inline u8 _irq_to_addr(enum lp8788_int_id id)
  47{
  48        return id / SIZE_REG;
  49}
  50
  51static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
  52{
  53        return _irq_to_addr(id) + BASE_INTEN_ADDR;
  54}
  55
  56static inline u8 _irq_to_mask(enum lp8788_int_id id)
  57{
  58        return 1 << (id % SIZE_REG);
  59}
  60
  61static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
  62{
  63        return enable << (id % SIZE_REG);
  64}
  65
  66static void lp8788_irq_enable(struct irq_data *data)
  67{
  68        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  69        irqd->enabled[data->hwirq] = 1;
  70}
  71
  72static void lp8788_irq_disable(struct irq_data *data)
  73{
  74        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  75        irqd->enabled[data->hwirq] = 0;
  76}
  77
  78static void lp8788_irq_bus_lock(struct irq_data *data)
  79{
  80        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  81
  82        mutex_lock(&irqd->irq_lock);
  83}
  84
  85static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
  86{
  87        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  88        enum lp8788_int_id irq = data->hwirq;
  89        u8 addr, mask, val;
  90
  91        addr = _irq_to_enable_addr(irq);
  92        mask = _irq_to_mask(irq);
  93        val = _irq_to_val(irq, irqd->enabled[irq]);
  94
  95        lp8788_update_bits(irqd->lp, addr, mask, val);
  96
  97        mutex_unlock(&irqd->irq_lock);
  98}
  99
 100static struct irq_chip lp8788_irq_chip = {
 101        .name                   = "lp8788",
 102        .irq_enable             = lp8788_irq_enable,
 103        .irq_disable            = lp8788_irq_disable,
 104        .irq_bus_lock           = lp8788_irq_bus_lock,
 105        .irq_bus_sync_unlock    = lp8788_irq_bus_sync_unlock,
 106};
 107
 108static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
 109{
 110        struct lp8788_irq_data *irqd = ptr;
 111        struct lp8788 *lp = irqd->lp;
 112        u8 status[NUM_REGS], addr, mask;
 113        bool handled;
 114        int i;
 115
 116        if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
 117                return IRQ_NONE;
 118
 119        for (i = 0 ; i < LP8788_INT_MAX ; i++) {
 120                addr = _irq_to_addr(i);
 121                mask = _irq_to_mask(i);
 122
 123                /* reporting only if the irq is enabled */
 124                if (status[addr] & mask) {
 125                        handle_nested_irq(irq_find_mapping(irqd->domain, i));
 126                        handled = true;
 127                }
 128        }
 129
 130        return handled ? IRQ_HANDLED : IRQ_NONE;
 131}
 132
 133static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
 134                        irq_hw_number_t hwirq)
 135{
 136        struct lp8788_irq_data *irqd = d->host_data;
 137        struct irq_chip *chip = &lp8788_irq_chip;
 138
 139        irq_set_chip_data(virq, irqd);
 140        irq_set_chip_and_handler(virq, chip, handle_edge_irq);
 141        irq_set_nested_thread(virq, 1);
 142
 143#ifdef CONFIG_ARM
 144        set_irq_flags(virq, IRQF_VALID);
 145#else
 146        irq_set_noprobe(virq);
 147#endif
 148
 149        return 0;
 150}
 151
 152static struct irq_domain_ops lp8788_domain_ops = {
 153        .map = lp8788_irq_map,
 154};
 155
 156int lp8788_irq_init(struct lp8788 *lp, int irq)
 157{
 158        struct lp8788_irq_data *irqd;
 159        int ret;
 160
 161        if (irq <= 0) {
 162                dev_warn(lp->dev, "invalid irq number: %d\n", irq);
 163                return 0;
 164        }
 165
 166        irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
 167        if (!irqd)
 168                return -ENOMEM;
 169
 170        irqd->lp = lp;
 171        irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
 172                                        &lp8788_domain_ops, irqd);
 173        if (!irqd->domain) {
 174                dev_err(lp->dev, "failed to add irq domain err\n");
 175                return -EINVAL;
 176        }
 177
 178        lp->irqdm = irqd->domain;
 179        mutex_init(&irqd->irq_lock);
 180
 181        ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
 182                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 183                                "lp8788-irq", irqd);
 184        if (ret) {
 185                dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
 186                return ret;
 187        }
 188
 189        lp->irq = irq;
 190
 191        return 0;
 192}
 193
 194void lp8788_irq_exit(struct lp8788 *lp)
 195{
 196        if (lp->irq)
 197                free_irq(lp->irq, lp->irqdm);
 198}
 199
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