target/linux/bcm27xx/patches-5.4/950-0029-irqchip-irq-bcm2836-Remove-regmap-and-syscon-use.patch

   1 From fef7d3ecae689f5f6eeb75da93f431d1a8a3200b Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Tue, 23 Jan 2018 16:52:45 +0000
   4 Subject: [PATCH] irqchip: irq-bcm2836: Remove regmap and syscon use
   5
   6 The syscon node defines a register range that duplicates that used by
   7 the local_intc node on bcm2836/7. Since irq-bcm2835 and irq-bcm2836 are
   8 built in and always present together (both drivers are enabled by
   9 CONFIG_ARCH_BCM2835), it is possible to replace the syscon usage with a
  10 global variable that simplifies the code. Doing so does lose the
  11 locking provided by regmap, but as only one side is using the regmap
  12 interface (irq-bcm2835 uses readl and write) there is no loss of
  13 atomicity.
  14
  15 See: https://github.com/raspberrypi/firmware/issues/926
  16
  17 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  18 ---
  19  drivers/irqchip/irq-bcm2835.c | 32 ++++++++++++--------------------
  20  drivers/irqchip/irq-bcm2836.c |  5 +++++
  21  2 files changed, 17 insertions(+), 20 deletions(-)
  22
  23 --- a/drivers/irqchip/irq-bcm2835.c
  24 +++ b/drivers/irqchip/irq-bcm2835.c
  25 @@ -41,8 +41,6 @@
  26  #include <linux/of_irq.h>
  27  #include <linux/irqchip.h>
  28  #include <linux/irqdomain.h>
  29 -#include <linux/mfd/syscon.h>
  30 -#include <linux/regmap.h>
  31
  32  #include <asm/exception.h>
  33  #include <asm/mach/irq.h>
  34 @@ -91,7 +89,7 @@ struct armctrl_ic {
  35         void __iomem *enable[NR_BANKS];
  36         void __iomem *disable[NR_BANKS];
  37         struct irq_domain *domain;
  38 -       struct regmap *local_regmap;
  39 +       void __iomem *local_base;
  40  };
  41
  42  static struct armctrl_ic intc __read_mostly;
  43 @@ -128,24 +126,20 @@ static void armctrl_unmask_irq(struct ir
  44         if (d->hwirq >= NUMBER_IRQS) {
  45                 if (num_online_cpus() > 1) {
  46                         unsigned int data;
  47 -                       int ret;
  48
  49 -                       if (!intc.local_regmap) {
  50 -                               pr_err("FIQ is disabled due to missing regmap\n");
  51 +                       if (!intc.local_base) {
  52 +                               pr_err("FIQ is disabled due to missing arm_local_intc\n");
  53                                 return;
  54                         }
  55
  56 -                       ret = regmap_read(intc.local_regmap,
  57 -                                         ARM_LOCAL_GPU_INT_ROUTING, &data);
  58 -                       if (ret) {
  59 -                               pr_err("Failed to read int routing %d\n", ret);
  60 -                               return;
  61 -                       }
  62 +                       data = readl_relaxed(intc.local_base +
  63 +                                            ARM_LOCAL_GPU_INT_ROUTING);
  64
  65                         data &= ~0xc;
  66                         data |= (1 << 2);
  67 -                       regmap_write(intc.local_regmap,
  68 -                                    ARM_LOCAL_GPU_INT_ROUTING, data);
  69 +                       writel_relaxed(data,
  70 +                                      intc.local_base +
  71 +                                      ARM_LOCAL_GPU_INT_ROUTING);
  72                 }
  73
  74                 writel_relaxed(REG_FIQ_ENABLE | hwirq_to_fiq(d->hwirq),
  75 @@ -231,12 +225,10 @@ static int __init armctrl_of_init(struct
  76         }
  77
  78         if (is_2836) {
  79 -               intc.local_regmap =
  80 -                       syscon_regmap_lookup_by_compatible("brcm,bcm2836-arm-local");
  81 -               if (IS_ERR(intc.local_regmap)) {
  82 -                       pr_err("Failed to get local register map. FIQ is disabled for cpus > 1\n");
  83 -                       intc.local_regmap = NULL;
  84 -               }
  85 +               extern void __iomem * __attribute__((weak)) arm_local_intc;
  86 +               intc.local_base = arm_local_intc;
  87 +               if (!intc.local_base)
  88 +                       pr_err("Failed to get local intc base. FIQ is disabled for cpus > 1\n");
  89         }
  90
  91         /* Make a duplicate irq range which is used to enable FIQ */
  92 --- a/drivers/irqchip/irq-bcm2836.c
  93 +++ b/drivers/irqchip/irq-bcm2836.c
  94 @@ -21,6 +21,9 @@ struct bcm2836_arm_irqchip_intc {
  95
  96  static struct bcm2836_arm_irqchip_intc intc  __read_mostly;
  97
  98 +void __iomem *arm_local_intc;
  99 +EXPORT_SYMBOL_GPL(arm_local_intc);
 100 +
 101  static void bcm2836_arm_irqchip_mask_per_cpu_irq(unsigned int reg_offset,
 102                                                  unsigned int bit,
 103                                                  int cpu)
 104 @@ -225,6 +228,8 @@ static int __init bcm2836_arm_irqchip_l1
 105                 panic("%pOF: unable to map local interrupt registers\n", node);
 106         }
 107
 108 +       arm_local_intc = intc.base;
 109 +
 110         bcm2835_init_local_timer_frequency();
 111
 112         intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1,