drivers/irqchip/irq-tb10x.c

   1 /*
   2  * Abilis Systems interrupt controller driver
   3  *
   4  * Copyright (C) Abilis Systems 2012
   5  *
   6  * Author: Christian Ruppert <christian.ruppert@abilis.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  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  */
  21
  22 #include <linux/interrupt.h>
  23 #include <linux/irqdomain.h>
  24 #include <linux/irq.h>
  25 #include <linux/irqchip.h>
  26 #include <linux/of_irq.h>
  27 #include <linux/of_address.h>
  28 #include <linux/of_platform.h>
  29 #include <linux/io.h>
  30 #include <linux/slab.h>
  31 #include <linux/bitops.h>
  32
  33 #define AB_IRQCTL_INT_ENABLE   0x00
  34 #define AB_IRQCTL_INT_STATUS   0x04
  35 #define AB_IRQCTL_SRC_MODE     0x08
  36 #define AB_IRQCTL_SRC_POLARITY 0x0C
  37 #define AB_IRQCTL_INT_MODE     0x10
  38 #define AB_IRQCTL_INT_POLARITY 0x14
  39 #define AB_IRQCTL_INT_FORCE    0x18
  40
  41 #define AB_IRQCTL_MAXIRQ       32
  42
  43 static inline void ab_irqctl_writereg(struct irq_chip_generic *gc, u32 reg,
  44         u32 val)
  45 {
  46         irq_reg_writel(gc, val, reg);
  47 }
  48
  49 static inline u32 ab_irqctl_readreg(struct irq_chip_generic *gc, u32 reg)
  50 {
  51         return irq_reg_readl(gc, reg);
  52 }
  53
  54 static int tb10x_irq_set_type(struct irq_data *data, unsigned int flow_type)
  55 {
  56         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  57         uint32_t im, mod, pol;
  58
  59         im = data->mask;
  60
  61         irq_gc_lock(gc);
  62
  63         mod = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_MODE) | im;
  64         pol = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_POLARITY) | im;
  65
  66         switch (flow_type & IRQF_TRIGGER_MASK) {
  67         case IRQ_TYPE_EDGE_FALLING:
  68                 pol ^= im;
  69                 break;
  70         case IRQ_TYPE_LEVEL_HIGH:
  71                 mod ^= im;
  72                 break;
  73         case IRQ_TYPE_NONE:
  74                 flow_type = IRQ_TYPE_LEVEL_LOW;
  75         case IRQ_TYPE_LEVEL_LOW:
  76                 mod ^= im;
  77                 pol ^= im;
  78                 break;
  79         case IRQ_TYPE_EDGE_RISING:
  80                 break;
  81         default:
  82                 irq_gc_unlock(gc);
  83                 pr_err("%s: Cannot assign multiple trigger modes to IRQ %d.\n",
  84                         __func__, data->irq);
  85                 return -EBADR;
  86         }
  87
  88         irqd_set_trigger_type(data, flow_type);
  89         irq_setup_alt_chip(data, flow_type);
  90
  91         ab_irqctl_writereg(gc, AB_IRQCTL_SRC_MODE, mod);
  92         ab_irqctl_writereg(gc, AB_IRQCTL_SRC_POLARITY, pol);
  93         ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, im);
  94
  95         irq_gc_unlock(gc);
  96
  97         return IRQ_SET_MASK_OK;
  98 }
  99
 100 static void tb10x_irq_cascade(struct irq_desc *desc)
 101 {
 102         struct irq_domain *domain = irq_desc_get_handler_data(desc);
 103         unsigned int irq = irq_desc_get_irq(desc);
 104
 105         generic_handle_irq(irq_find_mapping(domain, irq));
 106 }
 107
 108 static int __init of_tb10x_init_irq(struct device_node *ictl,
 109                                         struct device_node *parent)
 110 {
 111         int i, ret, nrirqs = of_irq_count(ictl);
 112         struct resource mem;
 113         struct irq_chip_generic *gc;
 114         struct irq_domain *domain;
 115         void __iomem *reg_base;
 116
 117         if (of_address_to_resource(ictl, 0, &mem)) {
 118                 pr_err("%s: No registers declared in DeviceTree.\n",
 119                         ictl->name);
 120                 return -EINVAL;
 121         }
 122
 123         if (!request_mem_region(mem.start, resource_size(&mem),
 124                 ictl->name)) {
 125                 pr_err("%s: Request mem region failed.\n", ictl->name);
 126                 return -EBUSY;
 127         }
 128
 129         reg_base = ioremap(mem.start, resource_size(&mem));
 130         if (!reg_base) {
 131                 ret = -EBUSY;
 132                 pr_err("%s: ioremap failed.\n", ictl->name);
 133                 goto ioremap_fail;
 134         }
 135
 136         domain = irq_domain_add_linear(ictl, AB_IRQCTL_MAXIRQ,
 137                                         &irq_generic_chip_ops, NULL);
 138         if (!domain) {
 139                 ret = -ENOMEM;
 140                 pr_err("%s: Could not register interrupt domain.\n",
 141                         ictl->name);
 142                 goto irq_domain_add_fail;
 143         }
 144
 145         ret = irq_alloc_domain_generic_chips(domain, AB_IRQCTL_MAXIRQ,
 146                                 2, ictl->name, handle_level_irq,
 147                                 IRQ_NOREQUEST, IRQ_NOPROBE,
 148                                 IRQ_GC_INIT_MASK_CACHE);
 149         if (ret) {
 150                 pr_err("%s: Could not allocate generic interrupt chip.\n",
 151                         ictl->name);
 152                 goto gc_alloc_fail;
 153         }
 154
 155         gc = domain->gc->gc[0];
 156         gc->reg_base                         = reg_base;
 157
 158         gc->chip_types[0].type               = IRQ_TYPE_LEVEL_MASK;
 159         gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
 160         gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
 161         gc->chip_types[0].chip.irq_set_type  = tb10x_irq_set_type;
 162         gc->chip_types[0].regs.mask          = AB_IRQCTL_INT_ENABLE;
 163
 164         gc->chip_types[1].type               = IRQ_TYPE_EDGE_BOTH;
 165         gc->chip_types[1].chip.name          = gc->chip_types[0].chip.name;
 166         gc->chip_types[1].chip.irq_ack       = irq_gc_ack_set_bit;
 167         gc->chip_types[1].chip.irq_mask      = irq_gc_mask_clr_bit;
 168         gc->chip_types[1].chip.irq_unmask    = irq_gc_mask_set_bit;
 169         gc->chip_types[1].chip.irq_set_type  = tb10x_irq_set_type;
 170         gc->chip_types[1].regs.ack           = AB_IRQCTL_INT_STATUS;
 171         gc->chip_types[1].regs.mask          = AB_IRQCTL_INT_ENABLE;
 172         gc->chip_types[1].handler            = handle_edge_irq;
 173
 174         for (i = 0; i < nrirqs; i++) {
 175                 unsigned int irq = irq_of_parse_and_map(ictl, i);
 176
 177                 irq_set_chained_handler_and_data(irq, tb10x_irq_cascade,
 178                                                  domain);
 179         }
 180
 181         ab_irqctl_writereg(gc, AB_IRQCTL_INT_ENABLE, 0);
 182         ab_irqctl_writereg(gc, AB_IRQCTL_INT_MODE, 0);
 183         ab_irqctl_writereg(gc, AB_IRQCTL_INT_POLARITY, 0);
 184         ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, ~0UL);
 185
 186         return 0;
 187
 188 gc_alloc_fail:
 189         irq_domain_remove(domain);
 190 irq_domain_add_fail:
 191         iounmap(reg_base);
 192 ioremap_fail:
 193         release_mem_region(mem.start, resource_size(&mem));
 194         return ret;
 195 }
 196 IRQCHIP_DECLARE(tb10x_intc, "abilis,tb10x-ictl", of_tb10x_init_irq);