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