--- /dev/null
+From 95fa6dbe58f286a8f87cb37b7516232eb678de2d Mon Sep 17 00:00:00 2001
+From: Sander Vanheule <sander@svanheule.net>
+Date: Sat, 9 Apr 2022 21:55:48 +0200
+Subject: [PATCH 3/6] gpio: realtek-otto: Support per-cpu interrupts
+
+On SoCs with multiple cores, it is possible that the GPIO interrupt
+controller supports assigning specific pins to one or more cores.
+
+IRQ balancing can be performed on a line-by-line basis if the parent
+interrupt is routed to all available cores, which is the default upon
+initialisation.
+
+Signed-off-by: Sander Vanheule <sander@svanheule.net>
+Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
+---
+ drivers/gpio/gpio-realtek-otto.c | 75 +++++++++++++++++++++++++++++++-
+ 1 file changed, 74 insertions(+), 1 deletion(-)
+
+--- a/drivers/gpio/gpio-realtek-otto.c
++++ b/drivers/gpio/gpio-realtek-otto.c
+@@ -1,6 +1,7 @@
+ // SPDX-License-Identifier: GPL-2.0-only
+
+ #include <linux/gpio/driver.h>
++#include <linux/cpumask.h>
+ #include <linux/irq.h>
+ #include <linux/minmax.h>
+ #include <linux/mod_devicetable.h>
+@@ -55,6 +56,8 @@
+ struct realtek_gpio_ctrl {
+ struct gpio_chip gc;
+ void __iomem *base;
++ void __iomem *cpumask_base;
++ struct cpumask cpu_irq_maskable;
+ raw_spinlock_t lock;
+ u16 intr_mask[REALTEK_GPIO_PORTS_PER_BANK];
+ u16 intr_type[REALTEK_GPIO_PORTS_PER_BANK];
+@@ -76,6 +79,11 @@ enum realtek_gpio_flags {
+ * fields, and [BA, DC] for 2-bit fields.
+ */
+ GPIO_PORTS_REVERSED = BIT(1),
++ /*
++ * Interrupts can be enabled per cpu. This requires a secondary IO
++ * range, where the per-cpu enable masks are located.
++ */
++ GPIO_INTERRUPTS_PER_CPU = BIT(2),
+ };
+
+ static struct realtek_gpio_ctrl *irq_data_to_ctrl(struct irq_data *data)
+@@ -250,14 +258,61 @@ static void realtek_gpio_irq_handler(str
+ chained_irq_exit(irq_chip, desc);
+ }
+
++static inline void __iomem *realtek_gpio_irq_cpu_mask(struct realtek_gpio_ctrl *ctrl,
++ unsigned int port, int cpu)
++{
++ return ctrl->cpumask_base + ctrl->port_offset_u8(port) +
++ REALTEK_GPIO_PORTS_PER_BANK * cpu;
++}
++
++static int realtek_gpio_irq_set_affinity(struct irq_data *data,
++ const struct cpumask *dest, bool force)
++{
++ struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data);
++ unsigned int line = irqd_to_hwirq(data);
++ unsigned int port = line / 8;
++ unsigned int port_pin = line % 8;
++ void __iomem *irq_cpu_mask;
++ unsigned long flags;
++ int cpu;
++ u8 v;
++
++ if (!ctrl->cpumask_base)
++ return -ENXIO;
++
++ raw_spin_lock_irqsave(&ctrl->lock, flags);
++
++ for_each_cpu(cpu, &ctrl->cpu_irq_maskable) {
++ irq_cpu_mask = realtek_gpio_irq_cpu_mask(ctrl, port, cpu);
++ v = ioread8(irq_cpu_mask);
++
++ if (cpumask_test_cpu(cpu, dest))
++ v |= BIT(port_pin);
++ else
++ v &= ~BIT(port_pin);
++
++ iowrite8(v, irq_cpu_mask);
++ }
++
++ raw_spin_unlock_irqrestore(&ctrl->lock, flags);
++
++ irq_data_update_effective_affinity(data, dest);
++
++ return 0;
++}
++
+ static int realtek_gpio_irq_init(struct gpio_chip *gc)
+ {
+ struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+ unsigned int port;
++ int cpu;
+
+ for (port = 0; (port * 8) < gc->ngpio; port++) {
+ realtek_gpio_write_imr(ctrl, port, 0, 0);
+ realtek_gpio_clear_isr(ctrl, port, GENMASK(7, 0));
++
++ for_each_cpu(cpu, &ctrl->cpu_irq_maskable)
++ iowrite8(GENMASK(7, 0), realtek_gpio_irq_cpu_mask(ctrl, port, cpu));
+ }
+
+ return 0;
+@@ -269,6 +324,7 @@ static struct irq_chip realtek_gpio_irq_
+ .irq_mask = realtek_gpio_irq_mask,
+ .irq_unmask = realtek_gpio_irq_unmask,
+ .irq_set_type = realtek_gpio_irq_set_type,
++ .irq_set_affinity = realtek_gpio_irq_set_affinity,
+ };
+
+ static const struct of_device_id realtek_gpio_of_match[] = {
+@@ -293,8 +349,10 @@ static int realtek_gpio_probe(struct pla
+ unsigned int dev_flags;
+ struct gpio_irq_chip *girq;
+ struct realtek_gpio_ctrl *ctrl;
++ struct resource *res;
+ u32 ngpios;
+- int err, irq;
++ unsigned int nr_cpus;
++ int cpu, err, irq;
+
+ ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl)
+@@ -355,6 +413,21 @@ static int realtek_gpio_probe(struct pla
+ girq->init_hw = realtek_gpio_irq_init;
+ }
+
++ cpumask_clear(&ctrl->cpu_irq_maskable);
++
++ if ((dev_flags & GPIO_INTERRUPTS_PER_CPU) && irq > 0) {
++ ctrl->cpumask_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
++ if (IS_ERR(ctrl->cpumask_base))
++ return dev_err_probe(dev, PTR_ERR(ctrl->cpumask_base),
++ "missing CPU IRQ mask registers");
++
++ nr_cpus = resource_size(res) / REALTEK_GPIO_PORTS_PER_BANK;
++ nr_cpus = min(nr_cpus, num_present_cpus());
++
++ for (cpu = 0; cpu < nr_cpus; cpu++)
++ cpumask_set_cpu(cpu, &ctrl->cpu_irq_maskable);
++ }
++
+ return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
+ }
+
projects / openwrt / staging / noltari.git / blobdiff