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
  70        irqd->enabled[data->hwirq] = 1;
  71}
  72
  73static void lp8788_irq_disable(struct irq_data *data)
  74{
  75        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  76
  77        irqd->enabled[data->hwirq] = 0;
  78}
  79
  80static void lp8788_irq_bus_lock(struct irq_data *data)
  81{
  82        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  83
  84        mutex_lock(&irqd->irq_lock);
  85}
  86
  87static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
  88{
  89        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  90        enum lp8788_int_id irq = data->hwirq;
  91        u8 addr, mask, val;
  92
  93        addr = _irq_to_enable_addr(irq);
  94        mask = _irq_to_mask(irq);
  95        val = _irq_to_val(irq, irqd->enabled[irq]);
  96
  97        lp8788_update_bits(irqd->lp, addr, mask, val);
  98
  99        mutex_unlock(&irqd->irq_lock);
 100}
 101
 102static struct irq_chip lp8788_irq_chip = {
 103        .name                   = "lp8788",
 104        .irq_enable             = lp8788_irq_enable,
 105        .irq_disable            = lp8788_irq_disable,
 106        .irq_bus_lock           = lp8788_irq_bus_lock,
 107        .irq_bus_sync_unlock    = lp8788_irq_bus_sync_unlock,
 108};
 109
 110static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
 111{
 112        struct lp8788_irq_data *irqd = ptr;
 113        struct lp8788 *lp = irqd->lp;
 114        u8 status[NUM_REGS], addr, mask;
 115        bool handled;
 116        int i;
 117
 118        if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
 119                return IRQ_NONE;
 120
 121        for (i = 0 ; i < LP8788_INT_MAX ; i++) {
 122                addr = _irq_to_addr(i);
 123                mask = _irq_to_mask(i);
 124
 125                /* reporting only if the irq is enabled */
 126                if (status[addr] & mask) {
 127                        handle_nested_irq(irq_find_mapping(irqd->domain, i));
 128                        handled = true;
 129                }
 130        }
 131
 132        return handled ? IRQ_HANDLED : IRQ_NONE;
 133}
 134
 135static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
 136                        irq_hw_number_t hwirq)
 137{
 138        struct lp8788_irq_data *irqd = d->host_data;
 139        struct irq_chip *chip = &lp8788_irq_chip;
 140
 141        irq_set_chip_data(virq, irqd);
 142        irq_set_chip_and_handler(virq, chip, handle_edge_irq);
 143        irq_set_nested_thread(virq, 1);
 144
 145#ifdef CONFIG_ARM
 146        set_irq_flags(virq, IRQF_VALID);
 147#else
 148        irq_set_noprobe(virq);
 149#endif
 150
 151        return 0;
 152}
 153
 154static const struct irq_domain_ops lp8788_domain_ops = {
 155        .map = lp8788_irq_map,
 156};
 157
 158int lp8788_irq_init(struct lp8788 *lp, int irq)
 159{
 160        struct lp8788_irq_data *irqd;
 161        int ret;
 162
 163        if (irq <= 0) {
 164                dev_warn(lp->dev, "invalid irq number: %d\n", irq);
 165                return 0;
 166        }
 167
 168        irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
 169        if (!irqd)
 170                return -ENOMEM;
 171
 172        irqd->lp = lp;
 173        irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
 174                                        &lp8788_domain_ops, irqd);
 175        if (!irqd->domain) {
 176                dev_err(lp->dev, "failed to add irq domain err\n");
 177                return -EINVAL;
 178        }
 179
 180        lp->irqdm = irqd->domain;
 181        mutex_init(&irqd->irq_lock);
 182
 183        ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
 184                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 185                                "lp8788-irq", irqd);
 186        if (ret) {
 187                dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
 188                return ret;
 189        }
 190
 191        lp->irq = irq;
 192
 193        return 0;
 194}
 195
 196void lp8788_irq_exit(struct lp8788 *lp)
 197{
 198        if (lp->irq)
 199                free_irq(lp->irq, lp->irqdm);
 200}
 201