drivers/irqchip/irq-gic-realview.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Special GIC quirks for the ARM RealView
   4  * Copyright (C) 2015 Linus Walleij
   5  */
   6 #include <linux/of.h>
   7 #include <linux/regmap.h>
   8 #include <linux/mfd/syscon.h>
   9 #include <linux/bitops.h>
  10 #include <linux/irqchip.h>
  11 #include <linux/irqchip/arm-gic.h>
  12
  13 #define REALVIEW_SYS_LOCK_OFFSET        0x20
  14 #define REALVIEW_SYS_PLD_CTRL1          0x74
  15 #define REALVIEW_EB_REVB_SYS_PLD_CTRL1  0xD8
  16 #define VERSATILE_LOCK_VAL              0xA05F
  17 #define PLD_INTMODE_MASK                BIT(22)|BIT(23)|BIT(24)
  18 #define PLD_INTMODE_LEGACY              0x0
  19 #define PLD_INTMODE_NEW_DCC             BIT(22)
  20 #define PLD_INTMODE_NEW_NO_DCC          BIT(23)
  21 #define PLD_INTMODE_FIQ_ENABLE          BIT(24)
  22
  23 /* For some reason RealView EB Rev B moved this register */
  24 static const struct of_device_id syscon_pldset_of_match[] = {
  25         {
  26                 .compatible = "arm,realview-eb11mp-revb-syscon",
  27                 .data = (void *)REALVIEW_EB_REVB_SYS_PLD_CTRL1,
  28         },
  29         {
  30                 .compatible = "arm,realview-eb11mp-revc-syscon",
  31                 .data = (void *)REALVIEW_SYS_PLD_CTRL1,
  32         },
  33         {
  34                 .compatible = "arm,realview-eb-syscon",
  35                 .data = (void *)REALVIEW_SYS_PLD_CTRL1,
  36         },
  37         {
  38                 .compatible = "arm,realview-pb11mp-syscon",
  39                 .data = (void *)REALVIEW_SYS_PLD_CTRL1,
  40         },
  41         {},
  42 };
  43
  44 static int __init
  45 realview_gic_of_init(struct device_node *node, struct device_node *parent)
  46 {
  47         struct regmap *map;
  48         struct device_node *np;
  49         const struct of_device_id *gic_id;
  50         u32 pld1_ctrl;
  51
  52         np = of_find_matching_node_and_match(NULL, syscon_pldset_of_match,
  53                                              &gic_id);
  54         if (!np)
  55                 return -ENODEV;
  56         pld1_ctrl = (u32)gic_id->data;
  57
  58         /* The PB11MPCore GIC needs to be configured in the syscon */
  59         map = syscon_node_to_regmap(np);
  60         if (!IS_ERR(map)) {
  61                 /* new irq mode with no DCC */
  62                 regmap_write(map, REALVIEW_SYS_LOCK_OFFSET,
  63                              VERSATILE_LOCK_VAL);
  64                 regmap_update_bits(map, pld1_ctrl,
  65                                    PLD_INTMODE_NEW_NO_DCC,
  66                                    PLD_INTMODE_MASK);
  67                 regmap_write(map, REALVIEW_SYS_LOCK_OFFSET, 0x0000);
  68                 pr_info("RealView GIC: set up interrupt controller to NEW mode, no DCC\n");
  69         } else {
  70                 pr_err("RealView GIC setup: could not find syscon\n");
  71                 return -ENODEV;
  72         }
  73         return gic_of_init(node, parent);
  74 }
  75 IRQCHIP_DECLARE(armtc11mp_gic, "arm,tc11mp-gic", realview_gic_of_init);
  76 IRQCHIP_DECLARE(armeb11mp_gic, "arm,eb11mp-gic", realview_gic_of_init);