drivers/mfd/tps65910-irq.c

   1 /*
   2  * tps65910-irq.c  --  TI TPS6591x
   3  *
   4  * Copyright 2010 Texas Instruments Inc.
   5  *
   6  * Author: Graeme Gregory <gg@slimlogic.co.uk>
   7  * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify it
  10  *  under  the terms of the GNU General  Public License as published by the
  11  *  Free Software Foundation;  either version 2 of the License, or (at your
  12  *  option) any later version.
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/bug.h>
  20 #include <linux/device.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/irq.h>
  23 #include <linux/gpio.h>
  24 #include <linux/mfd/tps65910.h>
  25
  26 static inline int irq_to_tps65910_irq(struct tps65910 *tps65910,
  27                                                         int irq)
  28 {
  29         return (irq - tps65910->irq_base);
  30 }
  31
  32 /*
  33  * This is a threaded IRQ handler so can access I2C/SPI.  Since all
  34  * interrupts are clear on read the IRQ line will be reasserted and
  35  * the physical IRQ will be handled again if another interrupt is
  36  * asserted while we run - in the normal course of events this is a
  37  * rare occurrence so we save I2C/SPI reads.  We're also assuming that
  38  * it's rare to get lots of interrupts firing simultaneously so try to
  39  * minimise I/O.
  40  */
  41 static irqreturn_t tps65910_irq(int irq, void *irq_data)
  42 {
  43         struct tps65910 *tps65910 = irq_data;
  44         u16 irq_sts;
  45         u16 irq_mask;
  46         u8 reg;
  47         int i;
  48
  49         tps65910->read(tps65910, TPS65910_INT_STS, 1, &reg);
  50         irq_sts = reg;
  51         tps65910->read(tps65910, TPS65910_INT_STS2, 1, &reg);
  52         irq_sts |= reg << 8;
  53
  54         tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
  55         irq_mask = reg;
  56         tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
  57         irq_mask |= reg << 8;
  58
  59         irq_sts &= ~irq_mask;
  60
  61         if (!irq_sts)
  62                 return IRQ_NONE;
  63
  64         for (i = 0; i < TPS65910_NUM_IRQ; i++) {
  65
  66                 if (!(irq_sts & (1 << i)))
  67                         continue;
  68
  69                 handle_nested_irq(tps65910->irq_base + i);
  70         }
  71
  72         /* Write the STS register back to clear IRQs we handled */
  73         reg = irq_sts & 0xFF;
  74         tps65910->write(tps65910, TPS65910_INT_STS, 1, &reg);
  75         reg = irq_sts >> 8;
  76         tps65910->write(tps65910, TPS65910_INT_STS2, 1, &reg);
  77
  78         return IRQ_HANDLED;
  79 }
  80
  81 static void tps65910_irq_lock(struct irq_data *data)
  82 {
  83         struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
  84
  85         mutex_lock(&tps65910->irq_lock);
  86 }
  87
  88 static void tps65910_irq_sync_unlock(struct irq_data *data)
  89 {
  90         struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
  91         u16 reg_mask;
  92         u8 reg;
  93
  94         tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
  95         reg_mask = reg;
  96         tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
  97         reg_mask |= reg << 8;
  98
  99         if (tps65910->irq_mask != reg_mask) {
 100                 reg = tps65910->irq_mask & 0xFF;
 101                 tps65910->write(tps65910, TPS65910_INT_MSK, 1, &reg);
 102                 reg = tps65910->irq_mask >> 8;
 103                 tps65910->write(tps65910, TPS65910_INT_MSK2, 1, &reg);
 104         }
 105         mutex_unlock(&tps65910->irq_lock);
 106 }
 107
 108 static void tps65910_irq_enable(struct irq_data *data)
 109 {
 110         struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
 111
 112         tps65910->irq_mask &= ~( 1 << irq_to_tps65910_irq(tps65910, data->irq));
 113 }
 114
 115 static void tps65910_irq_disable(struct irq_data *data)
 116 {
 117         struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
 118
 119         tps65910->irq_mask |= ( 1 << irq_to_tps65910_irq(tps65910, data->irq));
 120 }
 121
 122 static struct irq_chip tps65910_irq_chip = {
 123         .name = "tps65910",
 124         .irq_bus_lock = tps65910_irq_lock,
 125         .irq_bus_sync_unlock = tps65910_irq_sync_unlock,
 126         .irq_disable = tps65910_irq_disable,
 127         .irq_enable = tps65910_irq_enable,
 128 };
 129
 130 int tps65910_irq_init(struct tps65910 *tps65910, int irq,
 131                     struct tps65910_platform_data *pdata)
 132 {
 133         int ret, cur_irq;
 134         int flags = IRQF_ONESHOT;
 135         u8 reg;
 136
 137         if (!irq) {
 138                 dev_warn(tps65910->dev, "No interrupt support, no core IRQ\n");
 139                 return -EINVAL;
 140         }
 141
 142         if (!pdata || !pdata->irq_base) {
 143                 dev_warn(tps65910->dev, "No interrupt support, no IRQ base\n");
 144                 return -EINVAL;
 145         }
 146
 147         /* Mask top level interrupts */
 148         reg = 0xFF;
 149         tps65910->write(tps65910, TPS65910_INT_MSK, 1, &reg);
 150         reg = 0x03;
 151         tps65910->write(tps65910, TPS65910_INT_MSK2, 1, &reg);
 152
 153         mutex_init(&tps65910->irq_lock);
 154         tps65910->chip_irq = irq;
 155         tps65910->irq_base = pdata->irq_base;
 156
 157         /* Register with genirq */
 158         for (cur_irq = tps65910->irq_base;
 159              cur_irq < TPS65910_NUM_IRQ + tps65910->irq_base;
 160              cur_irq++) {
 161                 irq_set_chip_data(cur_irq, tps65910);
 162                 irq_set_chip_and_handler(cur_irq, &tps65910_irq_chip,
 163                                          handle_edge_irq);
 164                 irq_set_nested_thread(cur_irq, 1);
 165
 166                 /* ARM needs us to explicitly flag the IRQ as valid
 167                  * and will set them noprobe when we do so. */
 168 #ifdef CONFIG_ARM
 169                 set_irq_flags(cur_irq, IRQF_VALID);
 170 #else
 171                 irq_set_noprobe(cur_irq);
 172 #endif
 173         }
 174
 175         ret = request_threaded_irq(irq, NULL, tps65910_irq, flags,
 176                                    "tps65910", tps65910);
 177         if (ret != 0)
 178                 dev_err(tps65910->dev, "Failed to request IRQ: %d\n", ret);
 179
 180         return ret;
 181 }
 182
 183 int tps65910_irq_exit(struct tps65910 *tps65910)
 184 {
 185         free_irq(tps65910->chip_irq, tps65910);
 186         return 0;
 187 }