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/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/tps65912.h>
  25
  26 static inline int irq_to_tps65912_irq(struct tps65912 *tps65912,
  27                                                         int irq)
  28 {
  29         return irq - tps65912->irq_base;
  30 }
  31
  32 /*
  33  * This is a threaded IRQ handler so can access I2C/SPI.  Since the
  34  * IRQ handler explicitly clears the IRQ it handles the IRQ line
  35  * will be reasserted and the physical IRQ will be handled again if
  36  * another interrupt is asserted while we run - in the normal course
  37  * of events this is a rare occurrence so we save I2C/SPI reads. We're
  38  * also assuming that it's rare to get lots of interrupts firing
  39  * simultaneously so try to minimise I/O.
  40  */
  41 static irqreturn_t tps65912_irq(int irq, void *irq_data)
  42 {
  43         struct tps65912 *tps65912 = irq_data;
  44         u32 irq_sts;
  45         u32 irq_mask;
  46         u8 reg;
  47         int i;
  48
  49
  50         tps65912->read(tps65912, TPS65912_INT_STS, 1, &reg);
  51         irq_sts = reg;
  52         tps65912->read(tps65912, TPS65912_INT_STS2, 1, &reg);
  53         irq_sts |= reg << 8;
  54         tps65912->read(tps65912, TPS65912_INT_STS3, 1, &reg);
  55         irq_sts |= reg << 16;
  56         tps65912->read(tps65912, TPS65912_INT_STS4, 1, &reg);
  57         irq_sts |= reg << 24;
  58
  59         tps65912->read(tps65912, TPS65912_INT_MSK, 1, &reg);
  60         irq_mask = reg;
  61         tps65912->read(tps65912, TPS65912_INT_MSK2, 1, &reg);
  62         irq_mask |= reg << 8;
  63         tps65912->read(tps65912, TPS65912_INT_MSK3, 1, &reg);
  64         irq_mask |= reg << 16;
  65         tps65912->read(tps65912, TPS65912_INT_MSK4, 1, &reg);
  66         irq_mask |= reg << 24;
  67
  68         irq_sts &= ~irq_mask;
  69         if (!irq_sts)
  70                 return IRQ_NONE;
  71
  72         for (i = 0; i < tps65912->irq_num; i++) {
  73                 if (!(irq_sts & (1 << i)))
  74                         continue;
  75
  76                 handle_nested_irq(tps65912->irq_base + i);
  77         }
  78
  79         /* Write the STS register back to clear IRQs we handled */
  80         reg = irq_sts & 0xFF;
  81         irq_sts >>= 8;
  82         if (reg)
  83                 tps65912->write(tps65912, TPS65912_INT_STS, 1, &reg);
  84         reg = irq_sts & 0xFF;
  85         irq_sts >>= 8;
  86         if (reg)
  87                 tps65912->write(tps65912, TPS65912_INT_STS2, 1, &reg);
  88         reg = irq_sts & 0xFF;
  89         irq_sts >>= 8;
  90         if (reg)
  91                 tps65912->write(tps65912, TPS65912_INT_STS3, 1, &reg);
  92         reg = irq_sts & 0xFF;
  93         if (reg)
  94                 tps65912->write(tps65912, TPS65912_INT_STS4, 1, &reg);
  95
  96         return IRQ_HANDLED;
  97 }
  98
  99 static void tps65912_irq_lock(struct irq_data *data)
 100 {
 101         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 102
 103         mutex_lock(&tps65912->irq_lock);
 104 }
 105
 106 static void tps65912_irq_sync_unlock(struct irq_data *data)
 107 {
 108         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 109         u32 reg_mask;
 110         u8 reg;
 111
 112         tps65912->read(tps65912, TPS65912_INT_MSK, 1, &reg);
 113         reg_mask = reg;
 114         tps65912->read(tps65912, TPS65912_INT_MSK2, 1, &reg);
 115         reg_mask |= reg << 8;
 116         tps65912->read(tps65912, TPS65912_INT_MSK3, 1, &reg);
 117         reg_mask |= reg << 16;
 118         tps65912->read(tps65912, TPS65912_INT_MSK4, 1, &reg);
 119         reg_mask |= reg << 24;
 120
 121         if (tps65912->irq_mask != reg_mask) {
 122                 reg = tps65912->irq_mask & 0xFF;
 123                 tps65912->write(tps65912, TPS65912_INT_MSK, 1, &reg);
 124                 reg = tps65912->irq_mask >> 8 & 0xFF;
 125                 tps65912->write(tps65912, TPS65912_INT_MSK2, 1, &reg);
 126                 reg = tps65912->irq_mask >> 16 & 0xFF;
 127                 tps65912->write(tps65912, TPS65912_INT_MSK3, 1, &reg);
 128                 reg = tps65912->irq_mask >> 24 & 0xFF;
 129                 tps65912->write(tps65912, TPS65912_INT_MSK4, 1, &reg);
 130         }
 131
 132         mutex_unlock(&tps65912->irq_lock);
 133 }
 134
 135 static void tps65912_irq_enable(struct irq_data *data)
 136 {
 137         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 138
 139         tps65912->irq_mask &= ~(1 << irq_to_tps65912_irq(tps65912, data->irq));
 140 }
 141
 142 static void tps65912_irq_disable(struct irq_data *data)
 143 {
 144         struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
 145
 146         tps65912->irq_mask |= (1 << irq_to_tps65912_irq(tps65912, data->irq));
 147 }
 148
 149 static struct irq_chip tps65912_irq_chip = {
 150         .name = "tps65912",
 151         .irq_bus_lock = tps65912_irq_lock,
 152         .irq_bus_sync_unlock = tps65912_irq_sync_unlock,
 153         .irq_disable = tps65912_irq_disable,
 154         .irq_enable = tps65912_irq_enable,
 155 };
 156
 157 int tps65912_irq_init(struct tps65912 *tps65912, int irq,
 158                             struct tps65912_platform_data *pdata)
 159 {
 160         int ret, cur_irq;
 161         int flags = IRQF_ONESHOT;
 162         u8 reg;
 163
 164         if (!irq) {
 165                 dev_warn(tps65912->dev, "No interrupt support, no core IRQ\n");
 166                 return 0;
 167         }
 168
 169         if (!pdata || !pdata->irq_base) {
 170                 dev_warn(tps65912->dev, "No interrupt support, no IRQ base\n");
 171                 return 0;
 172         }
 173
 174         /* Clear unattended interrupts */
 175         tps65912->read(tps65912, TPS65912_INT_STS, 1, &reg);
 176         tps65912->write(tps65912, TPS65912_INT_STS, 1, &reg);
 177         tps65912->read(tps65912, TPS65912_INT_STS2, 1, &reg);
 178         tps65912->write(tps65912, TPS65912_INT_STS2, 1, &reg);
 179         tps65912->read(tps65912, TPS65912_INT_STS3, 1, &reg);
 180         tps65912->write(tps65912, TPS65912_INT_STS3, 1, &reg);
 181         tps65912->read(tps65912, TPS65912_INT_STS4, 1, &reg);
 182         tps65912->write(tps65912, TPS65912_INT_STS4, 1, &reg);
 183
 184         /* Mask top level interrupts */
 185         tps65912->irq_mask = 0xFFFFFFFF;
 186
 187         mutex_init(&tps65912->irq_lock);
 188         tps65912->chip_irq = irq;
 189         tps65912->irq_base = pdata->irq_base;
 190
 191         tps65912->irq_num = TPS65912_NUM_IRQ;
 192
 193         /* Register with genirq */
 194         for (cur_irq = tps65912->irq_base;
 195              cur_irq < tps65912->irq_num + tps65912->irq_base;
 196              cur_irq++) {
 197                 irq_set_chip_data(cur_irq, tps65912);
 198                 irq_set_chip_and_handler(cur_irq, &tps65912_irq_chip,
 199                                          handle_edge_irq);
 200                 irq_set_nested_thread(cur_irq, 1);
 201                 /* ARM needs us to explicitly flag the IRQ as valid
 202                  * and will set them noprobe when we do so. */
 203 #ifdef CONFIG_ARM
 204                 set_irq_flags(cur_irq, IRQF_VALID);
 205 #else
 206                 irq_set_noprobe(cur_irq);
 207 #endif
 208         }
 209
 210         ret = request_threaded_irq(irq, NULL, tps65912_irq, flags,
 211                                    "tps65912", tps65912);
 212
 213         irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
 214         if (ret != 0)
 215                 dev_err(tps65912->dev, "Failed to request IRQ: %d\n", ret);
 216
 217         return ret;
 218 }
 219
 220 int tps65912_irq_exit(struct tps65912 *tps65912)
 221 {
 222         free_irq(tps65912->chip_irq, tps65912);
 223         return 0;
 224 }