irqchip: irq-bcm2835: Add 2836 FIQ support

Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Clome · Jul 31, 2017 · f297b0c · f297b0c
1 parent 4b8a57b
commit f297b0c
Showing 1 changed file with 41 additions and 2 deletions.
diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c
@@ -50,8 +50,11 @@
 #include <linux/of_irq.h>
 #include <linux/irqchip.h>
 #include <linux/irqdomain.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #include <asm/exception.h>
+#include <asm/mach/irq.h>
 
 /* Put the bank and irq (32 bits) into the hwirq */
 #define MAKE_HWIRQ(b, n) (((b) << 5) | (n))
@@ -69,6 +72,9 @@
 #define BANK0_VALID_MASK (BANK0_HWIRQ_MASK | BANK1_HWIRQ | BANK2_HWIRQ \
  | SHORTCUT1_MASK | SHORTCUT2_MASK)
 
+#undef ARM_LOCAL_GPU_INT_ROUTING
+#define ARM_LOCAL_GPU_INT_ROUTING 0x0c
+
 #define REG_FIQ_CONTROL 0x0c
 #define REG_FIQ_ENABLE 0x80
 #define REG_FIQ_DISABLE 0
@@ -94,6 +100,7 @@ struct armctrl_ic {
  void __iomem *enable[NR_BANKS];
  void __iomem *disable[NR_BANKS];
  struct irq_domain *domain;
+ struct regmap *local_regmap;
 };
 
 static struct armctrl_ic intc __read_mostly;
@@ -127,12 +134,35 @@ static void armctrl_mask_irq(struct irq_data *d)
 
 static void armctrl_unmask_irq(struct irq_data *d)
 {
- if (d->hwirq >= NUMBER_IRQS)
+ if (d->hwirq >= NUMBER_IRQS) {
+ if (num_online_cpus() > 1) {
+ unsigned int data;
+ int ret;
+
+ if (!intc.local_regmap) {
+ pr_err("FIQ is disabled due to missing regmap\n");
+ return;
+ }
+
+ ret = regmap_read(intc.local_regmap,
+ ARM_LOCAL_GPU_INT_ROUTING, &data);
+ if (ret) {
+ pr_err("Failed to read int routing %d\n", ret);
+ return;
+ }
+
+ data &= ~0xc;
+ data |= (1 << 2);
+ regmap_write(intc.local_regmap,
+ ARM_LOCAL_GPU_INT_ROUTING, data);
+ }
+
  writel_relaxed(REG_FIQ_ENABLE | hwirq_to_fiq(d->hwirq),
  intc.base + REG_FIQ_CONTROL);
- else
+ } else {
  writel_relaxed(HWIRQ_BIT(d->hwirq),
  intc.enable[HWIRQ_BANK(d->hwirq)]);
+ }
 }
 
 static struct irq_chip armctrl_chip = {
@@ -210,6 +240,15 @@ static int __init armctrl_of_init(struct device_node *node,
  set_handle_irq(bcm2835_handle_irq);
  }
 
+ if (is_2836) {
+ intc.local_regmap =
+ syscon_regmap_lookup_by_compatible("brcm,bcm2836-arm-local");
+ if (IS_ERR(intc.local_regmap)) {
+ pr_err("Failed to get local register map. FIQ is disabled for cpus > 1\n");
+ intc.local_regmap = NULL;
+ }
+ }
+
  /* Make a duplicate irq range which is used to enable FIQ */
  for (b = 0; b < NR_BANKS; b++) {
  for (i = 0; i < bank_irqs[b]; i++) {