arch/arm/mach-ux500/modem-irq-db5500.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  * Author: Stefan Nilsson <stefan.xk.nilsson@stericsson.com> for ST-Ericsson.
   4  * Author: Martin Persson <martin.persson@stericsson.com> for ST-Ericsson.
   5  * License terms: GNU General Public License (GPL), version 2.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/irq.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/io.h>
  13 #include <linux/slab.h>
  14
  15 #include <mach/id.h>
  16
  17 #define MODEM_INTCON_BASE_ADDR 0xBFFD3000
  18 #define MODEM_INTCON_SIZE 0xFFF
  19
  20 #define DEST_IRQ41_OFFSET 0x2A4
  21 #define DEST_IRQ43_OFFSET 0x2AC
  22 #define DEST_IRQ45_OFFSET 0x2B4
  23
  24 #define PRIO_IRQ41_OFFSET 0x6A4
  25 #define PRIO_IRQ43_OFFSET 0x6AC
  26 #define PRIO_IRQ45_OFFSET 0x6B4
  27
  28 #define ALLOW_IRQ_OFFSET 0x104
  29
  30 #define MODEM_INTCON_CPU_NBR 0x1
  31 #define MODEM_INTCON_PRIO_HIGH 0x0
  32
  33 #define MODEM_INTCON_ALLOW_IRQ41 0x0200
  34 #define MODEM_INTCON_ALLOW_IRQ43 0x0800
  35 #define MODEM_INTCON_ALLOW_IRQ45 0x2000
  36
  37 #define MODEM_IRQ_REG_OFFSET 0x4
  38
  39 struct modem_irq {
  40         void __iomem *modem_intcon_base;
  41 };
  42
  43
  44 static void setup_modem_intcon(void __iomem *modem_intcon_base)
  45 {
  46         /* IC_DESTINATION_BASE_ARRAY - Which CPU to receive the IRQ */
  47         writel(MODEM_INTCON_CPU_NBR, modem_intcon_base + DEST_IRQ41_OFFSET);
  48         writel(MODEM_INTCON_CPU_NBR, modem_intcon_base + DEST_IRQ43_OFFSET);
  49         writel(MODEM_INTCON_CPU_NBR, modem_intcon_base + DEST_IRQ45_OFFSET);
  50
  51         /* IC_PRIORITY_BASE_ARRAY - IRQ priority in modem IRQ controller */
  52         writel(MODEM_INTCON_PRIO_HIGH, modem_intcon_base + PRIO_IRQ41_OFFSET);
  53         writel(MODEM_INTCON_PRIO_HIGH, modem_intcon_base + PRIO_IRQ43_OFFSET);
  54         writel(MODEM_INTCON_PRIO_HIGH, modem_intcon_base + PRIO_IRQ45_OFFSET);
  55
  56         /* IC_ALLOW_ARRAY - IRQ enable */
  57         writel(MODEM_INTCON_ALLOW_IRQ41 |
  58                    MODEM_INTCON_ALLOW_IRQ43 |
  59                    MODEM_INTCON_ALLOW_IRQ45,
  60                    modem_intcon_base + ALLOW_IRQ_OFFSET);
  61 }
  62
  63 static irqreturn_t modem_cpu_irq_handler(int irq, void *data)
  64 {
  65         int real_irq;
  66         int virt_irq;
  67         struct modem_irq *mi = (struct modem_irq *)data;
  68
  69         /* Read modem side IRQ number from modem IRQ controller */
  70         real_irq = readl(mi->modem_intcon_base + MODEM_IRQ_REG_OFFSET) & 0xFF;
  71         virt_irq = IRQ_MODEM_EVENTS_BASE + real_irq;
  72
  73         pr_debug("modem_irq: Worker read addr 0x%X and got value 0x%X "
  74                  "which will be 0x%X (%d) which translates to "
  75                  "virtual IRQ 0x%X (%d)!\n",
  76                    (u32)mi->modem_intcon_base + MODEM_IRQ_REG_OFFSET,
  77                    real_irq,
  78                    real_irq & 0xFF,
  79                    real_irq & 0xFF,
  80                    virt_irq,
  81                    virt_irq);
  82
  83         if (virt_irq != 0)
  84                 generic_handle_irq(virt_irq);
  85
  86         pr_debug("modem_irq: Done handling virtual IRQ %d!\n", virt_irq);
  87
  88         return IRQ_HANDLED;
  89 }
  90
  91 static void create_virtual_irq(int irq, struct irq_chip *modem_irq_chip)
  92 {
  93         set_irq_chip(irq, modem_irq_chip);
  94         set_irq_handler(irq, handle_simple_irq);
  95         set_irq_flags(irq, IRQF_VALID);
  96
  97         pr_debug("modem_irq: Created virtual IRQ %d\n", irq);
  98 }
  99
 100 static int modem_irq_init(void)
 101 {
 102         int err;
 103         static struct irq_chip  modem_irq_chip;
 104         struct modem_irq *mi;
 105
 106         if (!cpu_is_u5500())
 107                 return -ENODEV;
 108
 109         pr_info("modem_irq: Set up IRQ handler for incoming modem IRQ %d\n",
 110                    IRQ_DB5500_MODEM);
 111
 112         mi = kmalloc(sizeof(struct modem_irq), GFP_KERNEL);
 113         if (!mi) {
 114                 pr_err("modem_irq: Could not allocate device\n");
 115                 return -ENOMEM;
 116         }
 117
 118         mi->modem_intcon_base =
 119                 ioremap(MODEM_INTCON_BASE_ADDR, MODEM_INTCON_SIZE);
 120         pr_debug("modem_irq: ioremapped modem_intcon_base from "
 121                  "phy 0x%x to virt 0x%x\n", MODEM_INTCON_BASE_ADDR,
 122                  (u32)mi->modem_intcon_base);
 123
 124         setup_modem_intcon(mi->modem_intcon_base);
 125
 126         modem_irq_chip = dummy_irq_chip;
 127         modem_irq_chip.name = "modem_irq";
 128
 129         /* Create the virtual IRQ:s needed */
 130         create_virtual_irq(MBOX_PAIR0_VIRT_IRQ, &modem_irq_chip);
 131         create_virtual_irq(MBOX_PAIR1_VIRT_IRQ, &modem_irq_chip);
 132         create_virtual_irq(MBOX_PAIR2_VIRT_IRQ, &modem_irq_chip);
 133
 134         err = request_threaded_irq(IRQ_DB5500_MODEM, NULL,
 135                                    modem_cpu_irq_handler, IRQF_ONESHOT,
 136                                    "modem_irq", mi);
 137         if (err)
 138                 pr_err("modem_irq: Could not register IRQ %d\n",
 139                        IRQ_DB5500_MODEM);
 140
 141         return 0;
 142 }
 143
 144 arch_initcall(modem_irq_init);