drivers: irqchip: Add snapshot of msm_show_resume_irq

Add a snapshot of the show resume IRQ driver from msm-5.15 'commit
12ba2ebcde0b ("irqchip: add snapshot of msm_show_resume_irq")'.

Updates:
    - Remove upstream dependency with irq-gic-v3.c where it registers
      for syscore ops and handle on our side instead
    - Get GICD base address per device and print HW IRQ when resuming
      from suspend.
    - Change GPL v2 license to GPL

Change-Id: I4c0ffd433e995305459f37cad24b9cbf8b8c4ee0
Signed-off-by: Rashid Zafar <quic_rzafar@quicinc.com>

drivers/irqchip/Kconfig

@@ -440,6 +440,16 @@ config QCOM_PDC
 	  Power Domain Controller driver to manage and configure wakeup
 	  IRQs for Qualcomm Technologies Inc (QTI) mobile chips.
 
+config QCOM_SHOW_RESUME_IRQ
+        tristate "Enable logging of interrupts that could have caused resume"
+        depends on PM
+        depends on ARM_GIC_V2 || ARM_GIC_V3
+        help
+          This option logs wake up interrupts that have triggered just before
+          the resume loop unrolls. It helps to debug to know any unnecessary
+          wake up interrupts that causes system to come out of low power modes.
+          Say Y if you want to debug why the system resumed.
+
 config QCOM_MPM
 	tristate "QCOM MPM"
 	depends on ARCH_QCOM

drivers/irqchip/Makefile

@@ -120,3 +120,4 @@ obj-$(CONFIG_IRQ_IDT3243X)		+= irq-idt3243x.o
 obj-$(CONFIG_APPLE_AIC)			+= irq-apple-aic.o
 obj-$(CONFIG_MCHP_EIC)			+= irq-mchp-eic.o
 obj-$(CONFIG_SUNPLUS_SP7021_INTC)	+= irq-sp7021-intc.o
+obj-$(CONFIG_QCOM_SHOW_RESUME_IRQ)      += msm_show_resume_irq.o

drivers/irqchip/msm_show_resume_irq.c

@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2011, 2014-2016, 2018, 2020-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/syscore_ops.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip/arm-gic-v3.h>
+#include <trace/hooks/cpuidle_psci.h>
+
+static void __iomem *base;
+static int msm_show_resume_irq_mask;
+module_param_named(debug_mask, msm_show_resume_irq_mask, int, 0664);
+
+static void msm_show_resume_irqs(void)
+{
+	unsigned int i;
+	u32 enabled;
+	u32 pending[32];
+	u32 gic_line_nr;
+	u32 typer;
+
+	if (!msm_show_resume_irq_mask)
+		return;
+
+	typer = readl_relaxed(base + GICD_TYPER);
+	gic_line_nr = min(GICD_TYPER_SPIS(typer), 1023u);
+
+	for (i = 0; i * 32 < gic_line_nr; i++) {
+		enabled = readl_relaxed(base + GICD_ICENABLER + i * 4);
+		pending[i] = readl_relaxed(base + GICD_ISPENDR + i * 4);
+		pending[i] &= enabled;
+	}
+
+	for (i = find_first_bit((unsigned long *)pending, gic_line_nr);
+	     i < gic_line_nr;
+	     i = find_next_bit((unsigned long *)pending, gic_line_nr, i + 1)) {
+
+		if (i < 32)
+			continue;
+
+		pr_warn("%s: HWIRQ %u\n", __func__, i);
+	}
+}
+
+static atomic_t cpus_in_s2idle;
+
+static void gic_s2idle_enter(void *unused, struct cpuidle_device *dev, bool s2idle)
+{
+	if (!s2idle)
+		return;
+
+	atomic_inc(&cpus_in_s2idle);
+}
+
+static void gic_s2idle_exit(void *unused, struct cpuidle_device *dev, bool s2idle)
+{
+	if (!s2idle)
+		return;
+
+	if (atomic_read(&cpus_in_s2idle) == num_online_cpus())
+		msm_show_resume_irqs();
+
+	atomic_dec(&cpus_in_s2idle);
+}
+
+static struct syscore_ops gic_syscore_ops = {
+	.resume = msm_show_resume_irqs,
+};
+
+static int msm_show_resume_probe(struct platform_device *pdev)
+{
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+	if (IS_ERR(base)) {
+		pr_err("%pOF: unable to map GICD registers\n", pdev->dev.of_node);
+		return -ENXIO;
+	}
+
+	register_syscore_ops(&gic_syscore_ops);
+	return 0;
+}
+
+static const struct of_device_id msm_show_resume_match_table[] = {
+	{ .compatible = "qcom,show-resume-irqs" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, msm_show_resume_match_table);
+
+static struct platform_driver msm_show_resume_dev_driver = {
+	.probe  = msm_show_resume_probe,
+	.driver = {
+		.name = "show-resume-irqs",
+		.of_match_table = msm_show_resume_match_table,
+	},
+};
+
+static int __init msm_show_resume_init(void)
+{
+	register_trace_prio_android_vh_cpuidle_psci_enter(gic_s2idle_enter, NULL, INT_MAX);
+	register_trace_prio_android_vh_cpuidle_psci_exit(gic_s2idle_exit, NULL, INT_MAX);
+
+	return platform_driver_register(&msm_show_resume_dev_driver);
+}
+
+
+#if IS_MODULE(CONFIG_QCOM_SHOW_RESUME_IRQ)
+module_init(msm_show_resume_init);
+#else
+pure_initcall(msm_show_resume_init);
+#endif
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. MSM Show resume IRQ");
+MODULE_LICENSE("GPL");