drivers/mfd/lp8788-irq.c

   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  */
  39 struct 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
  46 static inline u8 _irq_to_addr(enum lp8788_int_id id)
  47 {
  48         return id / SIZE_REG;
  49 }
  50
  51 static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
  52 {
  53         return _irq_to_addr(id) + BASE_INTEN_ADDR;
  54 }
  55
  56 static inline u8 _irq_to_mask(enum lp8788_int_id id)
  57 {
  58         return 1 << (id % SIZE_REG);
  59 }
  60
  61 static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
  62 {
  63         return enable << (id % SIZE_REG);
  64 }
  65
  66 static 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
  72 static 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
  78 static 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
  85 static 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
 100 static 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
 108 static 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
 133 static 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
 152 static struct irq_domain_ops lp8788_domain_ops = {
 153         .map = lp8788_irq_map,
 154 };
 155
 156 int 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
 194 void lp8788_irq_exit(struct lp8788 *lp)
 195 {
 196         if (lp->irq)
 197                 free_irq(lp->irq, lp->irqdm);
 198 }