drivers/irqchip/irq-gic-realview.c

   1 /*
   2  * Special GIC quirks for the ARM RealView
   3  * Copyright (C) 2015 Linus Walleij
   4  */
   5 #include <linux/of.h>
   6 #include <linux/regmap.h>
   7 #include <linux/mfd/syscon.h>
   8 #include <linux/bitops.h>
   9 #include <linux/irqchip.h>
  10 #include <linux/irqchip/arm-gic.h>
  11
  12 #define REALVIEW_SYS_LOCK_OFFSET        0x20
  13 #define REALVIEW_SYS_PLD_CTRL1          0x74
  14 #define REALVIEW_EB_REVB_SYS_PLD_CTRL1  0xD8
  15 #define VERSATILE_LOCK_VAL              0xA05F
  16 #define PLD_INTMODE_MASK                BIT(22)|BIT(23)|BIT(24)
  17 #define PLD_INTMODE_LEGACY              0x0
  18 #define PLD_INTMODE_NEW_DCC             BIT(22)
  19 #define PLD_INTMODE_NEW_NO_DCC          BIT(23)
  20 #define PLD_INTMODE_FIQ_ENABLE          BIT(24)
  21
  22 /* For some reason RealView EB Rev B moved this register */
  23 static const struct of_device_id syscon_pldset_of_match[] = {
  24         {
  25                 .compatible = "arm,realview-eb11mp-revb-syscon",
  26                 .data = (void *)REALVIEW_EB_REVB_SYS_PLD_CTRL1,
  27         },
  28         {
  29                 .compatible = "arm,realview-eb11mp-revc-syscon",
  30                 .data = (void *)REALVIEW_SYS_PLD_CTRL1,
  31         },
  32         {
  33                 .compatible = "arm,realview-eb-syscon",
  34                 .data = (void *)REALVIEW_SYS_PLD_CTRL1,
  35         },
  36         {
  37                 .compatible = "arm,realview-pb11mp-syscon",
  38                 .data = (void *)REALVIEW_SYS_PLD_CTRL1,
  39         },
  40         {},
  41 };
  42
  43 static int __init
  44 realview_gic_of_init(struct device_node *node, struct device_node *parent)
  45 {
  46         static struct regmap *map;
  47         struct device_node *np;
  48         const struct of_device_id *gic_id;
  49         u32 pld1_ctrl;
  50
  51         np = of_find_matching_node_and_match(NULL, syscon_pldset_of_match,
  52                                              &gic_id);
  53         if (!np)
  54                 return -ENODEV;
  55         pld1_ctrl = (u32)gic_id->data;
  56
  57         /* The PB11MPCore GIC needs to be configured in the syscon */
  58         map = syscon_node_to_regmap(np);
  59         if (!IS_ERR(map)) {
  60                 /* new irq mode with no DCC */
  61                 regmap_write(map, REALVIEW_SYS_LOCK_OFFSET,
  62                              VERSATILE_LOCK_VAL);
  63                 regmap_update_bits(map, pld1_ctrl,
  64                                    PLD_INTMODE_NEW_NO_DCC,
  65                                    PLD_INTMODE_MASK);
  66                 regmap_write(map, REALVIEW_SYS_LOCK_OFFSET, 0x0000);
  67                 pr_info("RealView GIC: set up interrupt controller to NEW mode, no DCC\n");
  68         } else {
  69                 pr_err("RealView GIC setup: could not find syscon\n");
  70                 return -ENODEV;
  71         }
  72         return gic_of_init(node, parent);
  73 }
  74 IRQCHIP_DECLARE(armtc11mp_gic, "arm,tc11mp-gic", realview_gic_of_init);
  75 IRQCHIP_DECLARE(armeb11mp_gic, "arm,eb11mp-gic", realview_gic_of_init);