drivers/mfd/lp8788-irq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * TI LP8788 MFD - interrupt handler
   4  *
   5  * Copyright 2012 Texas Instruments
   6  *
   7  * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
   8  */
   9
  10 #include <linux/delay.h>
  11 #include <linux/err.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/irq.h>
  14 #include <linux/irqdomain.h>
  15 #include <linux/device.h>
  16 #include <linux/mfd/lp8788.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19
  20 /* register address */
  21 #define LP8788_INT_1                    0x00
  22 #define LP8788_INTEN_1                  0x03
  23
  24 #define BASE_INTEN_ADDR                 LP8788_INTEN_1
  25 #define SIZE_REG                        8
  26 #define NUM_REGS                        3
  27
  28 /*
  29  * struct lp8788_irq_data
  30  * @lp               : used for accessing to lp8788 registers
  31  * @irq_lock         : mutex for enabling/disabling the interrupt
  32  * @domain           : IRQ domain for handling nested interrupt
  33  * @enabled          : status of enabled interrupt
  34  */
  35 struct lp8788_irq_data {
  36         struct lp8788 *lp;
  37         struct mutex irq_lock;
  38         struct irq_domain *domain;
  39         int enabled[LP8788_INT_MAX];
  40 };
  41
  42 static inline u8 _irq_to_addr(enum lp8788_int_id id)
  43 {
  44         return id / SIZE_REG;
  45 }
  46
  47 static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
  48 {
  49         return _irq_to_addr(id) + BASE_INTEN_ADDR;
  50 }
  51
  52 static inline u8 _irq_to_mask(enum lp8788_int_id id)
  53 {
  54         return 1 << (id % SIZE_REG);
  55 }
  56
  57 static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
  58 {
  59         return enable << (id % SIZE_REG);
  60 }
  61
  62 static void lp8788_irq_enable(struct irq_data *data)
  63 {
  64         struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  65
  66         irqd->enabled[data->hwirq] = 1;
  67 }
  68
  69 static void lp8788_irq_disable(struct irq_data *data)
  70 {
  71         struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  72
  73         irqd->enabled[data->hwirq] = 0;
  74 }
  75
  76 static void lp8788_irq_bus_lock(struct irq_data *data)
  77 {
  78         struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  79
  80         mutex_lock(&irqd->irq_lock);
  81 }
  82
  83 static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
  84 {
  85         struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
  86         enum lp8788_int_id irq = data->hwirq;
  87         u8 addr, mask, val;
  88
  89         addr = _irq_to_enable_addr(irq);
  90         mask = _irq_to_mask(irq);
  91         val = _irq_to_val(irq, irqd->enabled[irq]);
  92
  93         lp8788_update_bits(irqd->lp, addr, mask, val);
  94
  95         mutex_unlock(&irqd->irq_lock);
  96 }
  97
  98 static struct irq_chip lp8788_irq_chip = {
  99         .name                   = "lp8788",
 100         .irq_enable             = lp8788_irq_enable,
 101         .irq_disable            = lp8788_irq_disable,
 102         .irq_bus_lock           = lp8788_irq_bus_lock,
 103         .irq_bus_sync_unlock    = lp8788_irq_bus_sync_unlock,
 104 };
 105
 106 static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
 107 {
 108         struct lp8788_irq_data *irqd = ptr;
 109         struct lp8788 *lp = irqd->lp;
 110         u8 status[NUM_REGS], addr, mask;
 111         bool handled = false;
 112         int i;
 113
 114         if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
 115                 return IRQ_NONE;
 116
 117         for (i = 0 ; i < LP8788_INT_MAX ; i++) {
 118                 addr = _irq_to_addr(i);
 119                 mask = _irq_to_mask(i);
 120
 121                 /* reporting only if the irq is enabled */
 122                 if (status[addr] & mask) {
 123                         handle_nested_irq(irq_find_mapping(irqd->domain, i));
 124                         handled = true;
 125                 }
 126         }
 127
 128         return handled ? IRQ_HANDLED : IRQ_NONE;
 129 }
 130
 131 static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
 132                         irq_hw_number_t hwirq)
 133 {
 134         struct lp8788_irq_data *irqd = d->host_data;
 135         struct irq_chip *chip = &lp8788_irq_chip;
 136
 137         irq_set_chip_data(virq, irqd);
 138         irq_set_chip_and_handler(virq, chip, handle_edge_irq);
 139         irq_set_nested_thread(virq, 1);
 140         irq_set_noprobe(virq);
 141
 142         return 0;
 143 }
 144
 145 static const struct irq_domain_ops lp8788_domain_ops = {
 146         .map = lp8788_irq_map,
 147 };
 148
 149 int lp8788_irq_init(struct lp8788 *lp, int irq)
 150 {
 151         struct lp8788_irq_data *irqd;
 152         int ret;
 153
 154         if (irq <= 0) {
 155                 dev_warn(lp->dev, "invalid irq number: %d\n", irq);
 156                 return 0;
 157         }
 158
 159         irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
 160         if (!irqd)
 161                 return -ENOMEM;
 162
 163         irqd->lp = lp;
 164         irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
 165                                         &lp8788_domain_ops, irqd);
 166         if (!irqd->domain) {
 167                 dev_err(lp->dev, "failed to add irq domain err\n");
 168                 return -EINVAL;
 169         }
 170
 171         lp->irqdm = irqd->domain;
 172         mutex_init(&irqd->irq_lock);
 173
 174         ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
 175                                 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 176                                 "lp8788-irq", irqd);
 177         if (ret) {
 178                 dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
 179                 return ret;
 180         }
 181
 182         lp->irq = irq;
 183
 184         return 0;
 185 }
 186
 187 void lp8788_irq_exit(struct lp8788 *lp)
 188 {
 189         if (lp->irq)
 190                 free_irq(lp->irq, lp->irqdm);
 191 }