drivers/mfd/tps65912-irq.c

   1 /*
   2  * tps65912-irq.c  --  TI TPS6591x
   3  *
   4  * Copyright 2011 Texas Instruments Inc.
   5  *
   6  * Author: Margarita Olaya <magi@slimlogic.co.uk>
   7  *
   8  *  This program is free software; you can redistribute it and/or modify it
   9  *  under  the terms of the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the License, or (at your
  11  *  option) any later version.
  12  *
  13  * This driver is based on wm8350 implementation.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/bug.h>
  19 #include <linux/device.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/gpio.h>
  23 #include <linux/mfd/tps65912.h>
  24
  25 static inline int irq_to_tps65912_irq(struct tps65912 *tps65912,
  26                                                         int irq)
  27 {
  28         return irq - tps65912->irq_base;
  29 }
  30
  31 /*
  32  * This is a threaded IRQ handler so can access I2C/SPI.  Since the
  33  * IRQ handler explicitly clears the IRQ it handles the IRQ line
  34  * will be reasserted and the physical IRQ will be handled again if
  35  * another interrupt is asserted while we run - in the normal course
  36  * of events this is a rare occurrence so we save I2C/SPI reads. We're
  37  * also assuming that it's rare to get lots of interrupts firing
  38  * simultaneously so try to minimise I/O.
  39  */
  40 static irqreturn_t tps65912_irq(int irq, void *irq_data)
  41 {
  42         struct tps65912 *tps65912 = irq_data;
  43         u32 irq_sts;
  44         u32 irq_mask;
  45         u8 reg;
  46         int i;
  47
  48
  49         tps65912->read(tps65912, TPS65912_INT_STS, 1, &reg);
  50         irq_sts = reg;
  51         tps65912->read(tps65912, TPS65912_INT_STS2, 1, &reg);
  52         irq_sts |= reg << 8;
  53         tps65912->read(tps65912, TPS65912_INT_STS3, 1, &reg);
  54         irq_sts |= reg << 16;
  55         tps65912->read(tps65912, TPS65912_INT_STS4, 1, &reg);
  56         irq_sts |= reg << 24;
  57
  58         tps65912->read(tps65912, TPS65912_INT_MSK, 1, &reg);
  59         irq_mask = reg;
  60         tps65912->read(tps65912, TPS65912_INT_MSK2, 1, &reg);
  61         irq_mask |= reg << 8;
  62         tps65912->read(tps65912, TPS65912_INT_MSK3, 1, &reg);
  63         irq_mask |= reg << 16;
  64         tps65912->read(tps65912, TPS65912_INT_MSK4, 1, &reg);
  65         irq_mask |= reg << 24;
  66
  67         irq_sts &= ~irq_mask;
  68         if (!irq_sts)
  69                 return IRQ_NONE;
  70
  71         for (i = 0; i < tps65912->irq_num; i++) {
  72                 if (!(irq_sts & (1 << i)))
  73                         continue;
  74
  75                 handle_nested_irq(tps65912->irq_base + i);
  76         }
  77
  78         /* Write the STS register back to clear IRQs we handled */
  79         reg = irq_sts & 0xFF;
  80         irq_sts >>= 8;
  81         if (reg)
  82                 tps65912->write(tps65912, TPS65912_INT_STS, 1, &reg);
  83         reg = irq_sts & 0xFF;
  84         irq_sts >>= 8;
  85         if (reg)
  86                 tps65912->write(tps65912, TPS65912_INT_STS2, 1, &reg);
  87         reg = irq_sts & 0xFF;
  88         irq_sts >>= 8;
  89         if (reg)
  90                 tps65912->write(tps65912, TPS65912_INT_STS3, 1, &reg);
  91         reg = irq_sts & 0xFF;
  92         if (reg)
  93                 tps65912->write(tps65912, TPS65912_INT_STS4, 1, &reg);
  94
  95         return IRQ_HANDLED;
  96 }
  97
  98 static void tps65912_irq_lock(struct irq_data *data)
  99 {
 100         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 101
 102         mutex_lock(&tps65912->irq_lock);
 103 }
 104
 105 static void tps65912_irq_sync_unlock(struct irq_data *data)
 106 {
 107         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 108         u32 reg_mask;
 109         u8 reg;
 110
 111         tps65912->read(tps65912, TPS65912_INT_MSK, 1, &reg);
 112         reg_mask = reg;
 113         tps65912->read(tps65912, TPS65912_INT_MSK2, 1, &reg);
 114         reg_mask |= reg << 8;
 115         tps65912->read(tps65912, TPS65912_INT_MSK3, 1, &reg);
 116         reg_mask |= reg << 16;
 117         tps65912->read(tps65912, TPS65912_INT_MSK4, 1, &reg);
 118         reg_mask |= reg << 24;
 119
 120         if (tps65912->irq_mask != reg_mask) {
 121                 reg = tps65912->irq_mask & 0xFF;
 122                 tps65912->write(tps65912, TPS65912_INT_MSK, 1, &reg);
 123                 reg = tps65912->irq_mask >> 8 & 0xFF;
 124                 tps65912->write(tps65912, TPS65912_INT_MSK2, 1, &reg);
 125                 reg = tps65912->irq_mask >> 16 & 0xFF;
 126                 tps65912->write(tps65912, TPS65912_INT_MSK3, 1, &reg);
 127                 reg = tps65912->irq_mask >> 24 & 0xFF;
 128                 tps65912->write(tps65912, TPS65912_INT_MSK4, 1, &reg);
 129         }
 130
 131         mutex_unlock(&tps65912->irq_lock);
 132 }
 133
 134 static void tps65912_irq_enable(struct irq_data *data)
 135 {
 136         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 137
 138         tps65912->irq_mask &= ~(1 << irq_to_tps65912_irq(tps65912, data->irq));
 139 }
 140
 141 static void tps65912_irq_disable(struct irq_data *data)
 142 {
 143         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 144
 145         tps65912->irq_mask |= (1 << irq_to_tps65912_irq(tps65912, data->irq));
 146 }
 147
 148 static struct irq_chip tps65912_irq_chip = {
 149         .name = "tps65912",
 150         .irq_bus_lock = tps65912_irq_lock,
 151         .irq_bus_sync_unlock = tps65912_irq_sync_unlock,
 152         .irq_disable = tps65912_irq_disable,
 153         .irq_enable = tps65912_irq_enable,
 154 };
 155
 156 int tps65912_irq_init(struct tps65912 *tps65912, int irq,
 157                             struct tps65912_platform_data *pdata)
 158 {
 159         int ret, cur_irq;
 160         int flags = IRQF_ONESHOT;
 161         u8 reg;
 162
 163         if (!irq) {
 164                 dev_warn(tps65912->dev, "No interrupt support, no core IRQ\n");
 165                 return 0;
 166         }
 167
 168         if (!pdata || !pdata->irq_base) {
 169                 dev_warn(tps65912->dev, "No interrupt support, no IRQ base\n");
 170                 return 0;
 171         }
 172
 173         /* Clear unattended interrupts */
 174         tps65912->read(tps65912, TPS65912_INT_STS, 1, &reg);
 175         tps65912->write(tps65912, TPS65912_INT_STS, 1, &reg);
 176         tps65912->read(tps65912, TPS65912_INT_STS2, 1, &reg);
 177         tps65912->write(tps65912, TPS65912_INT_STS2, 1, &reg);
 178         tps65912->read(tps65912, TPS65912_INT_STS3, 1, &reg);
 179         tps65912->write(tps65912, TPS65912_INT_STS3, 1, &reg);
 180         tps65912->read(tps65912, TPS65912_INT_STS4, 1, &reg);
 181         tps65912->write(tps65912, TPS65912_INT_STS4, 1, &reg);
 182
 183         /* Mask top level interrupts */
 184         tps65912->irq_mask = 0xFFFFFFFF;
 185
 186         mutex_init(&tps65912->irq_lock);
 187         tps65912->chip_irq = irq;
 188         tps65912->irq_base = pdata->irq_base;
 189
 190         tps65912->irq_num = TPS65912_NUM_IRQ;
 191
 192         /* Register with genirq */
 193         for (cur_irq = tps65912->irq_base;
 194              cur_irq < tps65912->irq_num + tps65912->irq_base;
 195              cur_irq++) {
 196                 irq_set_chip_data(cur_irq, tps65912);
 197                 irq_set_chip_and_handler(cur_irq, &tps65912_irq_chip,
 198                                          handle_edge_irq);
 199                 irq_set_nested_thread(cur_irq, 1);
 200                 irq_clear_status_flags(cur_irq, IRQ_NOREQUEST | IRQ_NOPROBE);
 201         }
 202
 203         ret = request_threaded_irq(irq, NULL, tps65912_irq, flags,
 204                                    "tps65912", tps65912);
 205
 206         irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
 207         if (ret != 0)
 208                 dev_err(tps65912->dev, "Failed to request IRQ: %d\n", ret);
 209
 210         return ret;
 211 }
 212
 213 int tps65912_irq_exit(struct tps65912 *tps65912)
 214 {
 215         free_irq(tps65912->chip_irq, tps65912);
 216         return 0;
 217 }