Re: [PATCH V3 2/2] irqchip: qcom: Add IRQ combiner driver
From: agustinv
Date: Wed May 25 2016 - 10:38:41 EST
Adding linux-arm-kernel and linux-acpi
On 2016-05-13 12:16, Agustin Vega-Frias wrote:
Driver for interrupt combiners in the Top-level Control and Status
Registers (TCSR) hardware block in Qualcomm Technologies chips.
An interrupt combiner in this block combines a set of interrupts by
OR'ing the individual interrupt signals into a summary interrupt
signal routed to a parent interrupt controller, and provides read-
only, 32-bit registers to query the status of individual interrupts.
The status bit for IRQ n is bit (n % 32) within register (n / 32)
of the given combiner. Thus, each combiner can be described as a set
of register offsets and the number of IRQs managed.
Signed-off-by: Agustin Vega-Frias <agustinv@xxxxxxxxxxxxxx>
---
drivers/irqchip/Kconfig | 8 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/qcom-irq-combiner.c | 344
++++++++++++++++++++++++++++++++++++
3 files changed, 353 insertions(+)
create mode 100644 drivers/irqchip/qcom-irq-combiner.c
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index f582e0d..609ff28 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -245,3 +245,11 @@ config IRQ_MXS
config MVEBU_ODMI
bool
select GENERIC_MSI_IRQ_DOMAIN
+
+config QCOM_IRQ_COMBINER
+ bool "QCOM IRQ combiner support"
+ depends on ARCH_QCOM
+ select IRQ_DOMAIN
+ help
+ Say yes here to add support for the IRQ combiner devices embedded
+ in Qualcomm Technologies chips.
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b03cfcb..05c688b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -65,3 +65,4 @@ obj-$(CONFIG_INGENIC_IRQ) += irq-ingenic.o
obj-$(CONFIG_IMX_GPCV2) += irq-imx-gpcv2.o
obj-$(CONFIG_PIC32_EVIC) += irq-pic32-evic.o
obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o
+obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
diff --git a/drivers/irqchip/qcom-irq-combiner.c
b/drivers/irqchip/qcom-irq-combiner.c
new file mode 100644
index 0000000..b4f767c
--- /dev/null
+++ b/drivers/irqchip/qcom-irq-combiner.c
@@ -0,0 +1,344 @@
+/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Driver for interrupt combiners in the Top-level Control and Status
+ * Registers (TCSR) hardware block in Qualcomm Technologies chips.
+ * An interrupt combiner in this block combines a set of interrupts by
+ * OR'ing the individual interrupt signals into a summary interrupt
+ * signal routed to a parent interrupt controller, and provides read-
+ * only, 32-bit registers to query the status of individual
interrupts.
+ * The status bit for IRQ n is bit (n % 32) within register (n / 32)
+ * of the given combiner. Thus, each combiner can be described as a
set
+ * of register offsets and the number of IRQs managed.
+ */
+
+#include <linux/acpi.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+#define REG_SIZE 32
+
+struct combiner_reg {
+ void __iomem *addr;
+ unsigned long mask;
+};
+
+struct combiner {
+ struct irq_chip irq_chip;
+ struct irq_domain *domain;
+ int parent_irq;
+ u32 nirqs;
+ u32 nregs;
+ struct combiner_reg regs[0];
+};
+
+static inline u32 irq_register(int irq)
+{
+ return irq / REG_SIZE;
+}
+
+static inline u32 irq_bit(int irq)
+{
+ return irq % REG_SIZE;
+
+}
+
+static inline int irq_nr(u32 reg, u32 bit)
+{
+ return reg * REG_SIZE + bit;
+}
+
+/*
+ * Handler for the cascaded IRQ.
+ */
+static void combiner_handle_irq(struct irq_desc *desc)
+{
+ struct combiner *combiner = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 reg;
+
+ chained_irq_enter(chip, desc);
+
+ for (reg = 0; reg < combiner->nregs; reg++) {
+ int virq;
+ int hwirq;
+ u32 bit;
+ u32 status;
+
+ if (combiner->regs[reg].mask == 0)
+ continue;
+
+ status = readl_relaxed(combiner->regs[reg].addr);
+ status &= combiner->regs[reg].mask;
+
+ while (status) {
+ bit = __ffs(status);
+ status &= ~(1 << bit);
+ hwirq = irq_nr(reg, bit);
+ virq = irq_find_mapping(combiner->domain, hwirq);
+ if (virq >= 0)
+ generic_handle_irq(virq);
+
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+/*
+ * irqchip callbacks
+ */
+
+static void combiner_irq_chip_mask_irq(struct irq_data *data)
+{
+ struct combiner *combiner = irq_data_get_irq_chip_data(data);
+ struct combiner_reg *reg = combiner->regs +
irq_register(data->hwirq);
+
+ clear_bit(irq_bit(data->hwirq), ®->mask);
+}
+
+static void combiner_irq_chip_unmask_irq(struct irq_data *data)
+{
+ struct combiner *combiner = irq_data_get_irq_chip_data(data);
+ struct combiner_reg *reg = combiner->regs +
irq_register(data->hwirq);
+
+ set_bit(irq_bit(data->hwirq), ®->mask);
+}
+
+#ifdef CONFIG_SMP
+static int combiner_irq_chip_set_affinity(struct irq_data *data,
+ const struct cpumask *mask, bool force)
+{
+ struct combiner *combiner = irq_data_get_irq_chip_data(data);
+ struct irq_data *pdata = irq_get_irq_data(combiner->parent_irq);
+
+ if (pdata->chip && pdata->chip->irq_set_affinity)
+ return pdata->chip->irq_set_affinity(pdata, mask, force);
+ else
+ return -EINVAL;
+}
+#endif
+
+/*
+ * domain callbacks
+ */
+
+static int combiner_irq_map(struct irq_domain *domain, unsigned int
irq,
+ irq_hw_number_t hwirq)
+{
+ struct combiner *combiner = domain->host_data;
+
+ if (hwirq >= combiner->nirqs)
+ return -EINVAL;
+
+ irq_set_chip_and_handler(irq, &combiner->irq_chip, handle_level_irq);
+ irq_set_chip_data(irq, combiner);
+ irq_set_parent(irq, combiner->parent_irq);
+ irq_set_noprobe(irq);
+ return 0;
+}
+
+static void combiner_irq_unmap(struct irq_domain *domain, unsigned int
irq)
+{
+ irq_set_chip_and_handler(irq, NULL, NULL);
+ irq_set_chip_data(irq, NULL);
+ irq_set_parent(irq, -1);
+}
+
+static struct irq_domain_ops domain_ops = {
+ .map = combiner_irq_map,
+ .unmap = combiner_irq_unmap
+};
+
+/*
+ * Probing and initialization.
+ *
+ * Combiner devices reside inside the TCSR block so the resulting DSDT
+ * topology is:
+ *
+ * Device (TCS0)
+ * {
+ * Name (_HID, "QCOM80B0") // Qualcomm TCSR controller
+ * Name (_UID, 0)
+ *
+ * Method (_CRS, 0x0, Serialized) {
+ * Name (RBUF, ResourceTemplate ()
+ * {
+ * Memory32Fixed (ReadWrite, 0x2E10000,
0x00001000)
+ * })
+ * Return (RBUF)
+ * }
+ *
+ * Device (QIC0)
+ * {
+ * Name(_HID,"QCOM80B1") // Qualcomm TCSR IRQ combiner
+ * ...
+ * } // end Device QIC0
+ * ...
+ * }
+ *
+ * Thus all combiner devices same the same memory mapping from the
parent
+ * device.
+ */
+
+static int __init combiner_probe(struct platform_device *pdev)
+{
+ struct platform_device *tcsr_pdev;
+ struct combiner *combiner;
+ void __iomem *tcsr_base;
+ size_t alloc_sz;
+ u32 nregs;
+ u32 nirqs;
+
+ tcsr_pdev = to_platform_device(pdev->dev.parent);
+ tcsr_base = platform_get_drvdata(tcsr_pdev);
+ if (!tcsr_base)
+ return -ENODEV;
+
+ if (device_property_read_u32(&pdev->dev, "qcom,combiner-nr-irqs",
+ &nirqs)) {
+ dev_err(&pdev->dev, "Error reading number of IRQs\n");
+ return -EINVAL;
+ }
+
+ nregs = device_property_read_u32_array(&pdev->dev,
"qcom,combiner-regs",
+ NULL, 0);
+ if (nregs < DIV_ROUND_UP(nirqs, REG_SIZE)) {
+ dev_err(&pdev->dev, "Error reading regs property\n");
+ return -EINVAL;
+ }
+
+ alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) * nregs;
+ combiner = devm_kzalloc(&pdev->dev, alloc_sz, GFP_KERNEL);
+ if (combiner) {
+ int i;
+ u32 regs[nregs];
+
+ if (device_property_read_u32_array(&pdev->dev,
+ "qcom,combiner-regs",
+ regs, nregs)) {
+ dev_err(&pdev->dev, "Error reading regs property\n");
+ return -EINVAL;
+ }
+
+ combiner->nirqs = nirqs;
+ combiner->nregs = nregs;
+ for (i = 0; i < nregs; i++) {
+ combiner->regs[i].addr = tcsr_base + regs[i];
+ combiner->regs[i].mask = 0;
+ }
+ } else {
+ return -ENOMEM;
+ }
+
+ combiner->irq_chip.irq_mask = combiner_irq_chip_mask_irq;
+ combiner->irq_chip.irq_unmask = combiner_irq_chip_unmask_irq;
+#ifdef CONFIG_SMP
+ combiner->irq_chip.irq_set_affinity = combiner_irq_chip_set_affinity;
+#endif
+
+ combiner->parent_irq = platform_get_irq(pdev, 0);
+ if (combiner->parent_irq <= 0) {
+ dev_err(&pdev->dev, "Error getting IRQ resource\n");
+ return -EINVAL;
+ }
+
+ combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, nirqs,
+ &domain_ops, combiner);
+ if (!combiner->domain)
+ /* Errors printed by irq_domain_create_linear */
+ return -ENODEV;
+
+ irq_set_chained_handler_and_data(combiner->parent_irq,
+ combiner_handle_irq, combiner);
+
+ if (device_property_read_string(&pdev->dev, "qcom,combiner-name",
+ &combiner->irq_chip.name) != 0)
+ combiner->irq_chip.name = "qcom-irq-combiner";
+
+ dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
+ combiner->parent_irq, nirqs, combiner->regs[0].addr);
+ return 0;
+}
+
+static const struct acpi_device_id qcom_irq_combiner_acpi_match[] = {
+ { "QCOM80B1", },
+ { }
+};
+
+static struct platform_driver qcom_irq_combiner_probe = {
+ .driver = {
+ .name = "qcom-irq-combiner",
+ .owner = THIS_MODULE,
+ .acpi_match_table = ACPI_PTR(qcom_irq_combiner_acpi_match),
+ },
+ .probe = combiner_probe,
+};
+
+static int __init register_qcom_irq_combiner(void)
+{
+ return platform_driver_register(&qcom_irq_combiner_probe);
+}
+arch_initcall(register_qcom_irq_combiner);
+
+static int __init tcsr_probe(struct platform_device *pdev)
+{
+ struct resource *mr;
+ void __iomem *tcsr_base;
+
+ mr = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (mr == NULL) {
+ dev_err(&pdev->dev, "Error getting memory resource\n");
+ return -EINVAL;
+ }
+
+ tcsr_base = devm_ioremap_resource(&pdev->dev, mr);
+ if (IS_ERR(tcsr_base)) {
+ dev_err(&pdev->dev, "Error mapping memory resource\n");
+ return PTR_ERR(tcsr_base);
+ }
+
+ dev_info(&pdev->dev, "Initialized TCSR block @%pa\n", &mr->start);
+ platform_set_drvdata(pdev, tcsr_base);
+ return 0;
+}
+
+static const struct acpi_device_id qcom_tcsr_acpi_match[] = {
+ { "QCOM80B0", },
+ { }
+};
+
+static struct platform_driver qcom_tcsr_probe = {
+ .driver = {
+ .name = "qcom-tcsr",
+ .owner = THIS_MODULE,
+ .acpi_match_table = ACPI_PTR(qcom_tcsr_acpi_match),
+ },
+ .probe = tcsr_probe,
+};
+
+static int __init register_qcom_tcsr(void)
+{
+ return platform_driver_register(&qcom_tcsr_probe);
+}
+arch_initcall(register_qcom_tcsr);
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum,
a Linux Foundation Collaborative Project.
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum,
a Linux Foundation Collaborative Project.